WorldWideScience

Sample records for achievement performances stagnate

  1. Transuranics Laboratory, achievements and performance

    International Nuclear Information System (INIS)

    The Marine and Aquatic Radioecology Group (MARG) was established in 1985 with the main scope of analysing the consequences of the Palomares accident in the adjacent Mediterranean ecosystem. From then on and up to now , this Group has extended its investigations to other European marine environments, such as the Spanish Mediterranean margin, the Artic and the Atlantic. The main research of long-lived radionuclides (plutonium, americium and Cs-137) determining the orography influence, riverine inputs and their geo-chemical associations. This group is currently accomplishing new challenges on the radioecology field such as the development of techniques for transuranics speciation to determine their geo-chemical association to the main sediment compounds. Natural and anthropogenic radionuclides distribution on salt-marsh areas affected by dry-wet periods is being studied as well as the possibilities of fusing crossed techniques for dating recent sediments (pollen, anthropogenic, ''210 Pb, etc). The Laboratory performance description, the procedures used, calculations, challenges and gaps are described in this report. (Author) 22 refs

  2. IMPORTANCE OF ACHIEVEMENT MOTIVATION IN SPORTS PERFORMANCE

    OpenAIRE

    Jyoti A Upadhye; N Chandrappa

    2014-01-01

    The present article defines the psychological construct of Achievement motivation and its influence on Sportsman to achieve their goals and to improve their performance level. Achievement Motivation is a mindset that leads people to set for themselves realistic but challenging goals. In Achievement Motivation can calculate mathematically by taking a person's desire to succeed and subtracting their fear of failure. When a student is motivated, he is inspired to pursue greater a...

  3. Revitalizing stagnated policy processes

    NARCIS (Netherlands)

    Termeer, C.J.A.M.; Kessener, B.

    2007-01-01

    Many complex policy processes face stagnations. People involved sense that continuing along existing paths will not produce those outcomes that are desired and deemed necessary. But changing and developing new action strategies is difficult. This article presents the results of an action research th

  4. Impact of Metacognition on Guitar Performance Achievement

    OpenAIRE

    YOKUŞ, Tuba

    2013-01-01

    This study has been carried out to determine the impact of the development of metacognition on guitar performance achievement in the individual instrument guitar lesson, which is included in the Bachelor’s program of Music Teacher Education in Marmara University Atatürk Faculty of Education, Department of Fine Arts Education, in Turkey. “Experimental Design with Pretest–Posttest Control Group” has been used, in order to achieve the objective of the study. The study sample (N=10) consists of g...

  5. Achieving scale strategies for sustained competitive performance.

    Science.gov (United States)

    Grube, Mark E; Gish, Ryan S; Tkach, Sasha N

    2008-05-01

    Growth to achieve scale requires the following strategic initiatives: Having a clear understanding of what the organization is and what it wants to become. Ensuring a structured and rigorous growth process. Leveraging size to achieve benefits of scale. Recognizing the importance of physicians, ambulatory care, and primary care. Establishing and maintaining accountability as growth occurs.

  6. Capital Accumulation and the Dynamics of secular stagnation

    OpenAIRE

    Le Garrec, Gilles; Touze, Vincent

    2016-01-01

    We characterize the dynamics of secular stagnation as a permanent regime switching from a full employment equilibrium to an underemployment equilibrium. In the latter, the natural interest rate is negative, and the economy is in deáation. Due to the non negativity condition imposed on policy rate, the zero lower bond (ZLB) applies which prevents targeting ináation. The secular stagnation equilibrium is achieved in a standard overlapping generations model with capital accumulati...

  7. User-Level Device Drivers: Achieved Performance

    Institute of Scientific and Technical Information of China (English)

    Ben Leslie; Gernot Heiser; Peter Chubb; Nicholas Fitzroy-Dale; Stefan G(o)tz; Charles Gray; Luke Macpherson; Daniel Potts; Yue-Ting Shen; Kevin Elphinstone

    2005-01-01

    Running device drivers as unprivileged user-level code, encapsulated into their own process, has often been proposed as a technique for increasing system robustness. However, in the past, systems based on user-level drivers have generally exhibited poor I/O performance. Consequently, user-level device drivers have never caught on to any significant degree. In this paper we demonstrate that it is possible to build systems which employ user-level device drivers, without significant performance degradation, even for high-bandwidth devices such as Gigabit Ethernet.

  8. Classroom Environment, Achievement Goals and Maths Performance: Gender Differences

    Science.gov (United States)

    Gherasim, Loredana Ruxandra; Butnaru, Simona; Mairean, Cornelia

    2013-01-01

    This study investigated how gender shapes the relationships between classroom environment, achievement goals and maths performance. Seventh-grade students ("N"?=?498) from five urban secondary schools filled in achievement goal orientations and classroom environment scales at the beginning of the second semester. Maths performance was assessed as…

  9. The stagnation of international law

    NARCIS (Netherlands)

    Pauwelyn, Joost; Wessel, R.A.; Wouters, Jan

    2012-01-01

    Traditional international law and its instruments are stagnating both in terms of quantity and quality. New, alternative forms of cross-border cooperation, in particular processes of informal international lawmaking, have emerged and gained prominence since the 2000s in response to an increasingly d

  10. Total Performance Scorecard Redefining Management to Achieve Performance with Integrity

    CERN Document Server

    Rampersad, Hubert

    2003-01-01

    In the post-Enron climate corporate executives are increasingly pressured to increase productivity and create an ethical, trustworthy organizational climate. 'Total Performance Scorecard' introduces a concept of organizational improvement and change management that combines the Balanced Scorecard model with the learning organization theory. The TPS contains a personal balanced scorecard, which is tied to an organizational balanced scorecard. These scorecards reflect not only performance goals but personal learning and growth goals as well, and the organizational scorecards also address organiz

  11. Achieving High Performance on the i860 Microprocessor

    Science.gov (United States)

    Lee, King; Kutler, Paul (Technical Monitor)

    1998-01-01

    The i860 is a high performance microprocessor used in the Intel Touchstone project. This paper proposes a paradigm for programming the i860 that is modelled on the vector instructions of the Cray computers. Fortran callable assembler subroutines were written that mimic the concurrent vector instructions of the Cray. Cache takes the place of vector registers. Using this paradigm we have achieved twice the performance of compiled code on a traditional solve.

  12. Effects of Motivational and Situational Variables on Achievement Performance.

    Science.gov (United States)

    Boker, John R.; Games, Paul A.

    Problem-solving performance and goal-setting behavior were investigated in 156 undergraduates who, on Mehrabian's Achievement Scales, demonstrated either the motive to approach success or the motive to avoid failure. Different expectations of success or failure were induced by fictitious preperformance information. The degree of success or failure…

  13. School Performance Indicators, Accountability Ratings, and Student Achievement

    Science.gov (United States)

    Jackson, Shirley A.; Lunenburg, Fred C.

    2010-01-01

    Researchers have been challenged to find school-level characteristics that make a difference in student achievement. This study focused on a diverse sample of 24 middle schools to examine differences between schools rated Exemplary, Recognized, Academically Acceptable, and Academically Unacceptable on four performance indicator dimensions:…

  14. Performance Achievement and Analysis of Teaching during Choral Rehearsals.

    Science.gov (United States)

    Davis, Anita P.

    1998-01-01

    Evaluates teaching sequences in high-school choral rehearsals to provide insight into the relationship between ensemble achievement and performance preparation. Indicates that teacher pace improvement is unrelated to ensemble maturity, teacher verbalization may not relate to success, and teacher assistance and instructions decrease with student…

  15. How to Achieve Quality Business Performance in an Organization

    OpenAIRE

    Merima Bekri ć

    2013-01-01

    RQ: The research question is the influence of quality management on quality business performance.Purpose: Determine which top management approaches are essential for business excellence and leadership approaches that achieve quality business.Method: Analysis of articles from the Journal Organization from the last 5 years and one article from the Journal of Universal Excellent to obtain data.Results: Characteristics of managers and individual employees influence the quality of an organization'...

  16. The Role Of The Budgetary System In Achieving Enterprise Performance

    Directory of Open Access Journals (Sweden)

    Adriana Mihaela Ionescu

    2014-05-01

    Full Text Available The long-term existence of an enterprise can only be assured by achieving of the performance.In the current economic climate, the companies pay more attention to effective management of resources and use for this purpose different management tools of performance. Along with material and financial resources necessary to productive activities, the people in an organization represent more than a source of cost or consumption. Their systems of needs and values, along with degrees of motivation and satisfaction determine individual and organizational performance. This is why the managers are tasked to reconcile and correlate the economic performance of the organization with the skills and capabilities of the employees. Flexible approach to business organization and permanent training of the human resources are the ingredients of success of an enterprise that aims to adapt to the current business environment changes.

  17. Magnetic fusion: progress -> stagnation -> degradation

    Science.gov (United States)

    Zakharov, Leonid

    2012-10-01

    ``The theory of the failure of magnetic fusion,'' created in 2004 and presented to APS-2007 introduced the notion of the ``difficult'' and ``complicated'' stages of the program and described them details. At the first phase the emerging fusion science was created under strong leadership. Progress was visible on year to year basis, and the program was easy to manage. The complicated phase started in the late 1980s, when the plasma physics appeared to be incapable to implement the mission of ITER to test nuclear components of a fusion reactor. Then, the failure of TFTR (PPPL, USA) and JET (Culham, UK) in the mid 1990 to demonstrate QDT=1 and the blindness of their leaders to already visible means to resolve the problem, were a clear indication of an irreversible stagnation. In fact, right after 2007, it became clear that in the case of a large system of human ``particles'' (scientists) two phases have a continuation. The internal degrees of freedom, otherwise protected from external perturbations by a strong dedication to the scientific method, are now eroding and collapsing. The loss of science in addressing confinement, stability, power extraction, fueling, stationary regimes issues makes the current program irrelevant to fusion energy. A fresh approach should be taken.

  18. How to Achieve Quality Business Performance in an Organization

    Directory of Open Access Journals (Sweden)

    Merima Bekri ć

    2013-02-01

    Full Text Available RQ: The research question is the influence of quality management on quality business performance.Purpose: Determine which top management approaches are essential for business excellence and leadership approaches that achieve quality business.Method: Analysis of articles from the Journal Organization from the last 5 years and one article from the Journal of Universal Excellent to obtain data.Results: Characteristics of managers and individual employees influence the quality of an organization's performance and business excellence. This is rudimentary for an organization to perform successfully. The results show the weaknesses that an organization can improve in.Organization: The research study facilitates in improving long-term success of an organization. The results can assist in further decision-making and timely responses to changes in its internal and external environment.Society: Better business performance contributes to the wider environment, as this also ensures stability of an organization.Originality: A different approach in viewing management issuesand searching for improvements. There are not many review articles on this topic.Limitations: The analysis was conducted with only ten articles.

  19. 晋升机会缺失对员工工作绩效的影响--内在动机与内部地位感知的中介作用%Promotion Opportunity Stagnation and Job Performance:the Mediating---Role of Intrinsic Motivation and Perceived Insider Status

    Institute of Scientific and Technical Information of China (English)

    廖建桥; 景珍思; 刘文兴; 汪兴东

    2015-01-01

    This study tries to explore the side back of promotion opportunity stagnation, assuming that promotion opportunity stagnation should be one important factor of inhibiting employee j ob performance,and that the effect of promotion opportunity stagnation on j ob performance should be mediated by intrinsic motivation and perceived insider status.By the answers to the questionnaires and the analysis of 354 samples from a large installation company in China,the results indicated that,(1 )promotion opportunity stagnation had negative effects on employee j ob performance;(2 )promotion opportunity stagnation had negative effects on intrinsic motivation and perceived insider status;(3 )both intrinsic motivation and perceived insider status had positive effects on employee j ob performance;(4 )both intrinsic motivation and perceived insider status fully mediated the relationship between promotion opportunity stagnation and j ob performance.At last,we discuss implications of these results for research and practice and future directions.%探讨晋升机会缺失的负面影响,认为晋升机会缺失是阻碍员工工作绩效提升的重要影响因素,且晋升机会缺失是通过内在动机与内部地位感知最终影响到员工工作绩效。通过对来自一家大型安装企业的354名员工实证分析结果表明:①晋升机会缺失会显著降低员工工作绩效;②晋升机会缺失会显著降低内在动机与内部地位感知;③内在动机、内部地位感知显著正面影响员工工作绩效;④晋升机会缺失通过内在动机、内部地位感知,进而降低员工工作绩效。最后,讨论了相关理论和实践的启示以及未来的研究方向。

  20. Combinational concentration gradient confinement through stagnation flow.

    Science.gov (United States)

    Alicia, Toh G G; Yang, Chun; Wang, Zhiping; Nguyen, Nam-Trung

    2016-01-21

    Concentration gradient generation in microfluidics is typically constrained by two conflicting mass transport requirements: short characteristic times (τ) for precise temporal control of concentration gradients but at the expense of high flow rates and hence, high flow shear stresses (σ). To decouple the limitations from these parameters, here we propose the use of stagnation flows to confine concentration gradients within large velocity gradients that surround the stagnation point. We developed a modified cross-slot (MCS) device capable of feeding binary and combinational concentration sources in stagnation flows. We show that across the velocity well, source-sink pairs can form permanent concentration gradients. As source-sink concentration pairs are continuously supplied to the MCS, a permanently stable concentration gradient can be generated. Tuning the flow rates directly controls the velocity gradients, and hence the stagnation point location, allowing the confined concentration gradient to be focused. In addition, the flow rate ratio within the MCS rapidly controls (τ ∼ 50 ms) the location of the stagnation point and the confined combinational concentration gradients at low flow shear (0.2 Pa < σ < 2.9 Pa). The MCS device described in this study establishes the method for using stagnation flows to rapidly generate and position low shear combinational concentration gradients for shear sensitive biological assays. PMID:26671507

  1. Science Achievement for All: Improving Science Performance and Closing Achievement Gaps

    Science.gov (United States)

    Jackson, Julie K.; Ash, Gwynne

    2012-01-01

    This article addresses the serious and growing need to improve science instruction and science achievement for all students. We will describe the results of a 3-year study that transformed science instruction and student achievement at two high-poverty ethnically diverse public elementary schools in Texas. The school-wide intervention included…

  2. Vorticity amplification near the stagnation point of landing gear wheels

    Science.gov (United States)

    Feltham, G.; Ekmekci, A.

    2014-04-01

    The vicinity near the forward stagnation point of landing-gear wheels has been found to support a mechanism for oncoming streams of weak vorticity to collect, grow, and amplify into discrete large-scale vortical structures that then shed with a distinct periodicity. To the authors' knowledge, such a flow phenomenon has never been reported before for landing gear wheels, which are in essence finite (three-dimensional) cylinders. To gain further insight into this phenomenon, a detailed experimental study has been undertaken employing the hydrogen bubble visualization and Particle Image Velocimetry techniques. A very thin platinum wire, similar to those used in hydrogen bubble visualization applications, was placed upstream of the wheel model to produce two streams of weak vorticity (with opposite sign) that convected toward the model. As the vorticity streams enter the stagnation region of the wheels, significant flow deceleration and vorticity stretching act to collect, grow, and amplify the incoming vorticity streams into large-scale vortical structures. Experiments were performed at a fixed Reynolds number, with a value of 32 500 when defined based on the diameter of the wheel and a value of 21 based on the diameter of the vorticity-generating upstream wire. First, to establish a baseline, the natural flow field (without the presence of an upstream wire) was characterized, where experimentally determined values for the stagnation boundary-layer thickness and the velocity profile along the stagnation streamline were both found to agree with the values provided in the literature for two-dimensional cylinders. Subsequently, the dynamics of vorticity collection, growth, amplification, and shedding were studied. The size, stand-off distance and the shedding frequency of the vortical structures forming near the stagnation region were all found to strongly depend on the impingement location of the inbound vorticity on the wheel. A simple relationship between the non

  3. Performance-Based Pay as a Motivational Tool for Achieving Organisational Performance: An Exploratory Case Study

    OpenAIRE

    Francis Boachie-Mensah; Ophelia Delali Dogbe

    2011-01-01

    The issue of employees’ performance in furtherance of organisational objectives has occupied managementattention for long. Differences in levels of performance have been attributed to differences in skills and abilitieson the one hand, and to different theories of money on the other. This study examined the issue ofperformance-based pay as a motivational tool for achieving organisational performance, using the situation in amanufacturing company in Ghana as a case study. The main objective of...

  4. Approximate Model for Turbulent Stagnation Point Flow.

    Energy Technology Data Exchange (ETDEWEB)

    Dechant, Lawrence [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-01

    Here we derive an approximate turbulent self-similar model for a class of favorable pressure gradient wedge-like flows, focusing on the stagnation point limit. While the self-similar model provides a useful gross flow field estimate this approach must be combined with a near wall model is to determine skin friction and by Reynolds analogy the heat transfer coefficient. The combined approach is developed in detail for the stagnation point flow problem where turbulent skin friction and Nusselt number results are obtained. Comparison to the classical Van Driest (1958) result suggests overall reasonable agreement. Though the model is only valid near the stagnation region of cylinders and spheres it nonetheless provides a reasonable model for overall cylinder and sphere heat transfer. The enhancement effect of free stream turbulence upon the laminar flow is used to derive a similar expression which is valid for turbulent flow. Examination of free stream enhanced laminar flow suggests that the rather than enhancement of a laminar flow behavior free stream disturbance results in early transition to turbulent stagnation point behavior. Excellent agreement is shown between enhanced laminar flow and turbulent flow behavior for high levels, e.g. 5% of free stream turbulence. Finally the blunt body turbulent stagnation results are shown to provide realistic heat transfer results for turbulent jet impingement problems.

  5. Why did Danish women's life expectancy stagnate?

    DEFF Research Database (Denmark)

    Lindahl-Jacobsen, Rune; Oeppen, Jim; Rizzi, Silvia;

    2016-01-01

    The general health status of a population changes over time, generally in a positive direction. Some generations experience more unfavourable conditions than others. The health of Danish women in the interwar generations is an example of such a phenomenon. The stagnation in their life expectancy...... between 1977 and 1995 is thought to be related to their smoking behaviour. So far, no study has measured the absolute effect of smoking on the mortality of the interwar generations of Danish women and thus the stagnation in Danish women's life expectancy. We applied a method to estimate age......-specific smoking-attributable number of deaths to examine the effect of smoking on the trends in partial life expectancy of Danish women between age 50 and 85 from 1950 to 2012. We compared these trends to those for women in Sweden, where there was no similar stagnation in life expectancy. When smoking...

  6. Achievement Goals, Motivation, and Performance: A Closer Look.

    Science.gov (United States)

    Urdan, Tim; Pajares, Frank; Lapin, Amy Z.

    An achievement goal theory framework was used to examine the relations among goals and a number of other motivational constructs in a sample of middle school students. Participants were 189 eighth graders from a public school in the south. In one session students completed the attitude measures and in another session they completed a mathematics…

  7. Aggregate demand, functional finance and secular stagnation

    DEFF Research Database (Denmark)

    Skott, Peter

    2016-01-01

    This paper makes three main points. Fiscal policy, first, may be needed in the long run to maintain full employment and avoid secular stagnation. If fiscal policy is used in this way, second, the long-run debt ratio depends (i) inversely on the rate of growth, (ii) inversely on government consump...

  8. Safety and performance achievement of Indian nuclear power plant

    International Nuclear Information System (INIS)

    Full text: The Nuclear power programme in India at present is based mainly on series of pressurized heavy water reactor(PHWR). Starting from Rajesthan atomic power station comprising two unit of 200 MWe in 1973, the programme has come a long way with 17 units in operation includes two unit of 540 MWe at Turapur 3 and 4. Narora atomic power station commissioned in 1991 marked major indigenization and standardization of PHWR design. Which includes, double containment of reactor building, two diverse reactor protection system and emergency core cooling system. Further in 540 MWe at Tarapur, the safety systems have been divided into two groups to the extent possible. These groups are physically separated so that any common mode incident either inside or outside the reactor building would nor disabled more than one of these groups. Each group of safety system should meet the requirements of shutdown the reactor , remove decay heat from the fuel subsequent to shutdown, prevent any subsequent escalation of failures, minimize the escape of radioactivity, supply necessary information to the operators for assesment of the state of the plant. Group-1 is first line of defense safety systems i.e. Shut Down System-1 (SDS-1), Emergency Core Cooling System (ECCS) and all process water systems including shutdown cooling. Group-2 is the second safety systems i.e. Shut Down System-2 (SDS-2), containment isolation, Moderator cooling, Emergency water supply (fire fighting water with diesel driven pump) through Steam Generator. Status of the plant is monitored and controlled from Main Control Room (MCR) and it is done from supplementary control room in case of emergency. Each safety system is designed to achieve unavailability of 10-3 year/year or less. Indian nuclear power plant progressively attained excellent operation performance comparable to international benchmark with sustained efforts in operation and maintenance, development and nurturing of qualified human resources at

  9. Achieving intelligent performance in autonomous on-road driving

    Science.gov (United States)

    Schlenoff, Craig I.; Evans, John M.; Barbera, Anthony J.; Albus, James S.; Messina, Elena R.; Balakirsky, Stephen B.

    2004-12-01

    This paper describes NIST"s efforts in evaluating what it will take to achieve autonomous human-level driving skills in terms of time and funding. NIST has approached this problem from several perspectives: considering the current state-of-the-art in autonomous navigation and extrapolating from there, decomposing the tasks identified by the Department of Transportation for on-road driving and comparing that with accomplishments to date, analyzing computing power requirements by comparison with the human brain, and conducting a Delphi Forecast using the expert researchers in the field of autonomous driving. A detailed description of each of these approaches is provided along with the major finding from each approach and an overall picture of what it will take to achieve human level driving skills in autonomous vehicles.

  10. Cryogenics system: strategy to achieve nominal performance and reliable operation

    CERN Document Server

    Bremer, J; Casas, J; Claudet, S; Delikaris, D; Delruelle, N; Ferlin, G; Fluder, C; Perin, A; Perinic, G; Pezzetti, M; Pirotte, O; Tavian, L; Wagner, U

    2012-01-01

    During the LHC operation in 2010 and 2011, the cryogenic system has achieved an availability level fulfilling the overall requirement. To reach this level, the cryogenic system has profited like many other beam-dependent systems from the reduced beam parameters. Therefore, impacts of some failures occurred during the LHC operation were mitigated by using the overcapacity margin, the existing built-in redundancy in between adjacent sector cryogenic plants and the "cannibalization" of spares on two idle cryogenic plants. These two first years of operation were also crucial to identify the weaknesses of the present cryogenic maintenance plan and new issues like SEUs. After the LS1, nominal beam parameters are expected and the mitigated measures will be less effective or not applicable at all. Consequently, a consolidation plan to improve the MTBF and the MTTR of the LHC cryogenic system is under definition. Concerning shutdown periods, the present cryogenic sectorization imposes some restrictions in the type of ...

  11. Three Oil Giants Achieved Good Operating Performances in First Quarter

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ PetroChina announced performance results PetroChina released its operation data for the first quarter this year on April 15th. A manager in PetroChina said that the increase rate of production of PetroChina in the first quarter this year has created the best level since PetroChina registered in HK in 2000.

  12. Achieving Mixtures of Ultra-High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Mircea POPA

    2013-07-01

    Full Text Available Ultra-High Performance Concrete (UHPC is a relatively new concrete. According to [11] UHPC is that concrete which features compressive strength over C100/115 class. Up to this point standards for this type of concrete were not adopted, although its characteristic strength exceeds those specified in [33]. Its main property is high compressive strength. This provides the possibility of reducing the section of elements (beams or columns made of this type of concrete, while the load capacity remains high. The study consists in blending mixtures of UHPC made of varying proportions of materials. The authors have obtained strengths of up to 160 MPa. The materials used are: Portland cement, silica fume, quartz powder, steel fibers, superplasticiser, sand and crushed aggregate for concrete - andesite.

  13. WEIGHTS STAGNATION IN DYNAMIC LOCAL SEARCH FOR SAT

    Directory of Open Access Journals (Sweden)

    Abdelraouf Ishtaiwi

    2016-05-01

    Full Text Available Since 1991, tries were made to enhance the stochastic local search techniques (SLS. Some researchers turned their focus on studying the structure of the propositional satisfiability problems (SAT to better understand their complexity in order to come up with better algorithms. Other researchers focused in investigating new ways to develop heuristics that alter the search space based on some information gathered prior to or during the search process. Thus, many heuristics, enhancements and developments were introduced to improve SLS techniques performance during the last three decades. As a result a group of heuristics were introduced namely Dynamic Local Search (DLS that could outperform the systematic search techniques. Interestingly, a common characteristic of DLS heuristics is that they all depend on the use of weights during searching for satisfiable formulas. In our study we experimentally investigated the weights behaviors and movements during searching for satisfiability using DLS techniques, for simplicity, DDFW DLS heuristic is chosen. As a results of our studies we discovered that while solving hard SAT problems such as blocks world and graph coloring problems, weights stagnation occur in many areas within the search space. We conclude that weights stagnation occurrence is highly related to the level of the problem density, complexity and connectivity.

  14. Public debt, secular stagnation and functional finance

    DEFF Research Database (Denmark)

    Skott, Peter

    2016-01-01

    Fiscal policy and public debt may be required to maintain full employment and avoid secular stagnation. This conclusion emerges from a range of different models, including OLG specifications and stock-flow consistent (post-) Keynesian models. One of the determinants of the required long-run debt...... ratio is the rate of economic growth. Low growth leads to high debt, and empirical correlations between growth and debt may reflect this causal effect of growth on debt, rather than negative effects of debt on growth. A second result relates directly to austerity policies. The level of government...

  15. Stagnation Point Radiative Heating Relations for Venus Entry

    Science.gov (United States)

    Tauber, Michael E.; Palmer, Grant E.; Prabhu, Dinesh K.

    2012-01-01

    Improved analytic expressions for calculating the stagnation point radiative heating during entry into the atmosphere of Venus have been developed. These analytic expressions can be incorporated into entry trajectory simulation codes. Together with analytical expressions for convective heating at the stagnation point, the time-integrated total heat load at the stagnation point is used in determining the thickness of protective material required, and hence the mass of the fore body heatshield of uniform thickness.

  16. Predicting Examination Performance Using an Expanded Integrated Hierarchical Model of Test Emotions and Achievement Goals

    Science.gov (United States)

    Putwain, Dave; Deveney, Carolyn

    2009-01-01

    The aim of this study was to examine an expanded integrative hierarchical model of test emotions and achievement goal orientations in predicting the examination performance of undergraduate students. Achievement goals were theorised as mediating the relationship between test emotions and performance. 120 undergraduate students completed…

  17. Experimental and numerical investigation of reacting stagnation flow

    Science.gov (United States)

    Bergthorson, Jeff; Dimotakis, Paul

    2003-11-01

    Planar laminar premixed flames are stabilized in the stagnation flowfield of an impinging jet. These flames are studied experimentally through measurements of the axial velocity and CH radical profiles, the equivalence ratio, plate temperature, and the static (Bernoulli) pressure drop across the nozzle. The velocity measurements are performed using Particle Streak Velocimetry (PSV), a technique valuable in flame measurements due to the low particle-mass loading, high accuracy and short run times possible. The CH radical profile is measured using Planar Laser Induced Fluorescence (PLIF), which provides a very accurate marker for the reaction zone location. The experimental results are compared to predictions by a one-dimensional simulation which incorporates full chemistry. Difficulties in performing detailed comparisons between one-dimensional simulations and finite-nozzle-diameter experiments are discussed in the context of validating chemical kinetics models. To further investigate the validity of these chemical kinetics models, global flame properties such as extinction strain-rates are also investigated.

  18. Orality disorders in melancholia: acedia as stagnation

    Directory of Open Access Journals (Sweden)

    Ana Cecília Magtaz

    2012-09-01

    Full Text Available In this article valuable contributions by Lasègue, Freud and Abraham are discussed, as they are all indispensible to the understanding of orality disorders in melancholia. Although none of the above authors used the exact term "orality disorders," their understandings of both hysteria and melancholia are important in the debate surrounding the clinical treatment of these difficulties. Sadness is a common denominator for the authors, but contributions on acedia, the "noonday demon" mentioned by Agamben, are also important. Acedia is defined as stagnation, a desperate lack of vigor when faced with a wearying and demanding situation. Those who suffer from chronic acedia feel great inertia and are unable to envision a future. They see their creativity wane away, especially due to the painful isolation caused by what might be called anguished sadness - a denial of sadness through manic action.

  19. Construct Validity of the Computerized Continuous Performance Test with Measures of Intelligence, Achievement, and Behavior.

    Science.gov (United States)

    Campbell, Janice Whitten; And Others

    1991-01-01

    Administered Continuous Performance Test (CPT), Wechsler Intelligence Scale for Children-Revised, Wide Range Achievement Test-Revised, Bender Visual-Motor Gestalt Test, and reading comprehension subtest of Peabody Individual Achievement Test to 54 school-aged children and adolescents referred for evaluation of learning disabilities. Parents…

  20. Positive Biases in Self-Assessment of Mathematics Competence, Achievement Goals, and Mathematics Performance

    Science.gov (United States)

    Dupeyrat, Caroline; Escribe, Christian; Huet, Nathalie; Regner, Isabelle

    2011-01-01

    The study examined how biases in self-evaluations of math competence relate to achievement goals and progress in math achievement. It was expected that performance goals would be related to overestimation and mastery goals to accurate self-assessments. A sample of French high-school students completed a questionnaire measuring their math…

  1. The association between physical activity, cognitive performance, and academic achievement in adolescents

    NARCIS (Netherlands)

    Van Dijk, Martin; De Groot, Renate; Kirschner, Paul A.

    2011-01-01

    Van Dijk, M. L., De Groot, R. H. M., Kirschner, P. A. (2011, 24 March). The association between physical activity, cognitive performance, and academic achievement in adolescents. Presentation at the ICO Introduction course, Utrecht, The Netherlands.

  2. The GOALS Study: The association between physical activity, cognitive performance, and academic achievement in adolescents

    NARCIS (Netherlands)

    Van Dijk, Martin; De Groot, Renate; Kirschner, Paul A.

    2011-01-01

    Van Dijk, M. L., De Groot, R. H. M., & Kirschner, P. A. (2011, 26 April). The GOALS Study: The association between physical activity, cognitive performance, and academic achievement in adolescents. Presentation at the Learning & Cognition meeting, Heerlen, The Netherlands.

  3. Neuropsychological and Academic Achievement Correlates of Abnormal WISC-R Verbal-Performance Discrepancies.

    Science.gov (United States)

    Lueger, Robert J.; And Others

    1985-01-01

    Examined neuropsychological and academic achievement correlates of statistically abnormal verbal-performance discrepancies on the Wechsler Intelligence Scale for Children (Revised). Results indicated that abnormal discrepancies reflect specific aphasia deficits rather than generalized neuropsychological dysfunction and that academic achievement…

  4. Achieving Flexibility and Performance for Packet Forwarding and Data Center Management

    OpenAIRE

    Moon, Daekyeong

    2010-01-01

    Although today's networking equipment has achieved high performance and low cost by embedding forwarding logic in hardware, this has come at the price of severely reduced flexibility. In this dissertation, we address the problem of achieving both flexibility and performance in two networking domains: packet forwarding and data center networking. In packet forwarding, we present Software Defined Forwarding, a hybrid design that attempts to combine the high speed and low cost of hardware with ...

  5. On impulsively started convection: The case of stagnation point flow

    Energy Technology Data Exchange (ETDEWEB)

    Ramadan, K. [Department of Mechanical Engineering, Mu' tah University, P. O. Box 7, Karak 61710 (Jordan); Al-Nimr, M.A. [Department of Mechanical Engineering, Jordan University of Science and Technology, P. O. Box 3030, Irbid 22110 (Jordan)

    2011-12-15

    Transient convection in incompressible planar and axisymmetric point flow is analyzed numerically in this work, and the thermal boundary layer response to surface sudden heating and cooling in the two settings is presented and compared over a range of Prandtl number between 0.5 and 100. A comparison between surface sudden cooling and heating is performed and different criteria are established as to when surface sudden heating and cooling are equivalent in terms of the transition time. With no initial thermal boundary layer (surface and fluid are at the same temperature), the transition time from the initial steady state to the final steady state upon surface sudden cooling or heating is found to be a constant regardless of the surface heating or cooling extent above or below the initial surface temperature, and is dependent only on the Prandtl number. With the existence of an initial thermal boundary layer, the transition time is dependent upon the heating or cooling extent, the initial surface temperature, the Prandtl number and whether heating/cooling is towards building-up or demolishing the thermal boundary later. It takes longer time when surface sudden heating or cooling is towards demolishing the thermal boundary layer than building it up. With symmetric surface sudden cooling or heating above or below the far-field fluid temperature, the transition time is independent on the surface cooling or heating extent and is a function of only the Prandtl number. A considerable difference in the thermal boundary layer response in the two settings is found. The transition time from the initial to the final steady state in axisymmetric stagnation point flow is less than that in plane stagnation flow under the same conditions. (authors)

  6. Performance-Approach and Performance-Avoidance Classroom Goals and the Adoption of Personal Achievement Goals

    Science.gov (United States)

    Schwinger, Malte; Stiensmeier-Pelster, Joachim

    2011-01-01

    Background: Students' perceptions of classroom goals influence their adoption of personal goals. To assess different forms of classroom goals, recent studies have favoured an overall measure of performance classroom goals, compared to a two-dimensional assessment of performance-approach and performance-avoidance classroom goals (PAVCG). Aims: This…

  7. The effect of adaptive performance support system on learning achievements of students

    OpenAIRE

    Kommers, Piet; Stoyanov, Slavi; Mileva, Nevena; Martinez Mediano, Catalina

    2008-01-01

    The study compares the effectiveness of two performance support systems, adaptive and non-adaptive, on learning achievements of engineering students. In addition, the research design controls for a possible effect of learning style. The analysis reveals that students working with an adaptive performance support system score significantly higher than students using a non-adaptive performance system on a performance test across different learning styles. The only variation in the two experiment...

  8. Can achievement emotions be used to better understand motivation, learning, and performance in medical education?

    Science.gov (United States)

    Artino, Anthony R; Holmboe, Eric S; Durning, Steven J

    2012-01-01

    In this article, we consider an emergent theory of human emotion. The overarching purpose of the article is to introduce medical education researchers to the notion of achievement emotions and provide a brief overview of how this work can inform the theory, research, and practice of medical education. First, we define achievement emotions and describe one of the leading contemporary theories of achievement emotions, control-value theory (Pekrun R. 2006. The control-value theory of achievement emotions: Assumptions, corollaries, and implications for educational research and practice. Educ Psychol Rev 18:315-341.). Next, we distinguish between different types of achievement emotions, their proximal causes, and their consequences for motivation, learning, and performance, and we discuss several implications for educational practice. Finally, we end with a call for more research on achievement emotions in medical education to facilitate our understanding of emotions and their impact on important educational outcomes.

  9. A meta-analysis of self-reported achievement goals and nonself-report performance across three achievement domains (work, sports, and education.

    Directory of Open Access Journals (Sweden)

    Nico W Van Yperen

    Full Text Available During the past three decades, the achievement goal approach to achievement motivation has emerged as an influential area of research, and is dedicated to understanding the reasons behind the individual's drive to achieve competence and performance. However, the current literature on achievement goals is segmented rather than integrated. That is, citations across the three major and distinct achievement domains (work, education, and sports are more the exception than the rule and similarities and differences between findings for the different achievement domains have yet to be tested. The purpose of the present study was to examine the relationships between self-reported achievement goals and nonself-report performance through meta-analysis, and the moderating potential of achievement domain. Identifying achievement domain as moderator improves our understanding to which contexts we can (not generalize conclusions to, it helps to understand seemingly inconsistent findings, and opens avenues for future research on the underlying processes. Because the achievement goal (AG measure used in a study is partially confounded with achievement domain, we examined the moderating role of this variable as well. Our findings suggest that - overall - approach goals (either mastery or performance were associated positively with performance attainment, whereas avoidance goals (either mastery or performance were associated negatively with performance attainment. These relationships were moderated by achievement domain. For example, relative to the education or work domain, in the sports domain, we did not observe negative correlations between avoidance goals and performance. The absence of statistical moderation due to AG measure suggests that the observed moderation of achievement domain cannot be explained by the AG measure utilized. We suggest further steps to integrate the achievement goal literature, and accordingly, to broaden and deepen understanding of

  10. The effect of adaptive performance support system on learning achievements of students

    NARCIS (Netherlands)

    Kommers, Piet; Stoyanov, Slavi; Mileva, Nevena; Martinez Mediano, Catalina

    2008-01-01

    The study compares the effectiveness of two performance support systems, adaptive and non-adaptive, on learning achievements of engineering students. In addition, the research design controls for a possible effect of learning style. The analysis reveals that students working with an adaptive perform

  11. The impact of the achievement motive on athletic performance in adolescent football players.

    Science.gov (United States)

    Zuber, Claudia; Conzelmann, Achim

    2014-01-01

    Researchers largely agree that there is a positive relationship between achievement motivation and athletic performance, which is why the achievement motive is viewed as a potential criterion for talent. However, the underlying mechanism behind this relationship remains unclear. In talent and performance models, main effect, mediator and moderator models have been suggested. A longitudinal study was carried out among 140 13-year-old football talents, using structural equation modelling to determine which model best explains how hope for success (HS) and fear of failure (FF), which are the aspects of the achievement motive, motor skills and abilities that affect performance. Over a period of half a year, HS can to some extent explain athletic performance, but this relationship is not mediated by the volume of training, sport-specific skills or abilities, nor is the achievement motive a moderating variable. Contrary to expectations, FF does not explain any part of performance. Aside from HS, however, motor abilities and in particular skills also predict a significant part of performance. The study confirms the widespread assumption that the development of athletic performance in football depends on multiple factors, and in particular that HS is worth watching in the medium term as a predictor of talent.

  12. Corporate Governance as a Crucial Factor in Achieving Sustainable Corporate Performance

    OpenAIRE

    Julija Bistrova; Natalja Lace; Manuela Tvaronaviciene

    2014-01-01

    In the developed stock markets the corporate governance aspect is crucial in the stock portfolio selection process for investor seeking to achieve shareholder value sustainability. In the emerging markets the importance of the corporate governance role just starts to be realized by the investors and by the corporate managers. The present research, looking at the stock performance leaders and laggards, analyzes whether the corporate governance system matters to achieve long-term shareholder va...

  13. Predicting subjective vitality and performance in sports: the role of passion and achievement goals.

    Science.gov (United States)

    Li, Chiung-Huang

    2010-06-01

    The major purpose of this study was to test the hypothesized paths from dualistic passions through achievement goals to subjective vitality and performance in sports. 645 high school athletes participated. The proposed structural equation model, with relationships between dualistic passions and subjective vitality and sports performance mediated by achievement goals, fit the data well, especially for mastery-approach and performance-approach goals. Harmonious and obsessive passions may lead athletes to high performance via the adoption of mastery-approach goals. However, these passions seem to have two paths influencing personal functioning: direct effects make players feel energetic, and indirect effects on subjective vitality through adoption of mastery-approach and performance-approach goals.

  14. Performance on large-scale science tests: Item attributes that may impact achievement scores

    Science.gov (United States)

    Gordon, Janet Victoria

    Significant differences in achievement among ethnic groups persist on the eighth-grade science Washington Assessment of Student Learning (WASL). The WASL measures academic performance in science using both scenario and stand-alone question types. Previous research suggests that presenting target items connected to an authentic context, like scenario question types, can increase science achievement scores especially in underrepresented groups and thus help to close the achievement gap. The purpose of this study was to identify significant differences in performance between gender and ethnic subgroups by question type on the 2005 eighth-grade science WASL. MANOVA and ANOVA were used to examine relationships between gender and ethnic subgroups as independent variables with achievement scores on scenario and stand-alone question types as dependent variables. MANOVA revealed no significant effects for gender, suggesting that the 2005 eighth-grade science WASL was gender neutral. However, there were significant effects for ethnicity. ANOVA revealed significant effects for ethnicity and ethnicity by gender interaction in both question types. Effect sizes were negligible for the ethnicity by gender interaction. Large effect sizes between ethnicities on scenario question types became moderate to small effect sizes on stand-alone question types. This indicates the score advantage the higher performing subgroups had over the lower performing subgroups was not as large on stand-alone question types compared to scenario question types. A further comparison examined performance on multiple-choice items only within both question types. Similar achievement patterns between ethnicities emerged; however, achievement patterns between genders changed in boys' favor. Scenario question types appeared to register differences between ethnic groups to a greater degree than stand-alone question types. These differences may be attributable to individual differences in cognition

  15. The Role of General and Performance Self Esteem In Relation Academic Procrastination and Academic Achievement

    OpenAIRE

    Balkıs, Murat; Duru, Erdinç

    2010-01-01

    In this study, mediator role of general and performance self esteem were investigated in relation to the academic procrastination and reported academic achievement. The participants were 323 students who study different major fields at the Faculty of Education in Pamukkale University. Age range varied from 17 to 31. In this study, Aitken Procrastination Inventory, Rosenberg Self Esteem Inventory, Performance Self Esteem Subscale of State Self Esteem Scale and Personal Information Sheet w...

  16. Nuclear power performance and safety. V.2. Achievements in construction and operation

    International Nuclear Information System (INIS)

    The International Conference on Nuclear Power Performance and Safety, organized by the International Atomic Energy Agency, was held at the Austria Centre Vienna (ACV) in Vienna, Austria, from 28 September to 2 October 1987. The objective of the Conference was to promote an exchange of worldwide information on the current trends in the performance and safety of nuclear power and its fuel cycle, and to take a forward look at the expectations and objectives for the 1990s. This objective was accomplished through presentation and discussion of about 200 papers at the Conference. This is volume 2 of the Conference proceedings. The presentations in this volume were divided into the following sections: plant construction achievements (8 papers); plant availability achievements (12 papers); controlling and financing nuclear power cost (6 papers); achievements in technology transfer and infrastructure development (5 papers); advanced systems (9 papers). A separate abstract was prepared for each of these papers. Refs, figs and tabs

  17. Four Language Skills Performance, Academic Achievement, and Learning Strategy Use in Preservice Teacher Training Programs

    Science.gov (United States)

    Shawer, Saad Fathy

    2016-01-01

    This article examines the differences in language learning strategies (LLS) use between preservice teachers of English as a foreign language (EFL) and Arabic as a second language (ASL). It also examines the relationship between LLS use and language performance (academic achievement and four language skills) among ASL students. The study made use…

  18. Performance Concern, Contingent Self-Worth, and Responses to Repeated Achievement Failure in Second Graders

    Science.gov (United States)

    Smiley, Patricia A.; Coulson, Sheri L.; Greene, Joelle K.; Bono, Katherine L.

    2010-01-01

    Individual differences in emotion, cognitions, and task choice following achievement failure are found among four- to seven-year-olds. However, neither performance deterioration during failure nor generalization after failure--aspects of the helpless pattern in 10-year-olds--have been reliably demonstrated in this age group. In the present study,…

  19. Physical activity, cognitive performance, and academic achievement: an observational study in Dutch adolescents using accelerometers

    NARCIS (Netherlands)

    Van Dijk, Martin; De Groot, Renate; Savelberg, Hans; Van Acker, Frederik; Kirschner, Paul A.

    2013-01-01

    Van Dijk, M. L., De Groot, R. H. M., Savelberg, H. C. M., Van Acker, F. H. M., & Kirschner, P. A. (2013, 7 November). Physical activity, cognitive performance, and academic achievement: an observational study in Dutch adolescents using accelerometers. Paper presentation at ICO National Fall School 2

  20. Physical activity, cognitive performance, and academic achievement: an observational study in Dutch adolescents using accelerometers

    OpenAIRE

    Van Dijk, Martin; De Groot, Renate; Savelberg, Hans; Van Acker, Frederik; Kirschner, Paul A.

    2013-01-01

    Van Dijk, M. L., De Groot, R. H. M., Savelberg, H. C. M., Van Acker, F. H. M., & Kirschner, P. A. (2013, 7 November). Physical activity, cognitive performance, and academic achievement: an observational study in Dutch adolescents using accelerometers. Paper presentation at ICO National Fall School 2013, Maastricht, The Netherlands.

  1. Associations between physical activity, cognitive performance, and academic achievement in Dutch adolescents: The GOALS Study

    NARCIS (Netherlands)

    Van Dijk, Martin; De Groot, Renate; Savelberg, Hans; Van Acker, Frederik; Kirschner, Paul A.

    2013-01-01

    Van Dijk, M. L., De Groot, R. H. M., Van Acker, F., Savelberg, H. C. M., & Kirschner, P. A. (2013, 12 November). Associations between physical activity, cognitive performance, and academic achievement in Dutch adolescents: The GOALS Study. Presentation at the Learning and Cognition plenary, Heerlen,

  2. Associations between physical activity, cognitive performance, and academic achievement in Dutch adolescents: The GOALS Study

    OpenAIRE

    Van Dijk, Martin; De Groot, Renate; Savelberg, Hans; Van Acker, Frederik; Kirschner, Paul A.

    2013-01-01

    Van Dijk, M. L., De Groot, R. H. M., Van Acker, F., Savelberg, H. C. M., & Kirschner, P. A. (2013, 12 November). Associations between physical activity, cognitive performance, and academic achievement in Dutch adolescents: The GOALS Study. Presentation at the Learning and Cognition plenary, Heerlen, The Netherlands.

  3. A meta-analysis of the impact of situationally induced achievement goals on task performance

    NARCIS (Netherlands)

    Van Yperen, Nico W.; Blaga, Monica; Postmes, Thomas

    2015-01-01

    The purpose of this research was to meta-analyze studies which experimentally induced an achieve- ment goal state to examine its causal effect on the individual’s performance at the task at hand, and to investigate the moderator effects of feedback anticipation and time pressure. The data set compri

  4. Immigrant Children's Educational Achievement in Western Countries: Origin, Destination, and Community Effects on Mathematical Performance

    Science.gov (United States)

    Levels, Mark; Dronkers, Jaap; Kraaykamp, Gerbert

    2008-01-01

    This article explores the extent to which macro-level characteristics of destination countries, origin countries, and immigrant communities help explain differences in immigrant children's educational achievement. Using data from the 2003 PISA survey, we analyze the mathematical performance of 7,403 pupils from 35 different origin countries in 13…

  5. The effect of adaptive performance support system on learning achievements of students.

    NARCIS (Netherlands)

    Kommers, Piet; Stoyanov, Slavi; Mileva, Nevena; Martínez Mediano, Catalina

    2008-01-01

    Kommers, P., Stoyanov, S., Mileva, N., & Kommers, P., Stoyanov, S., Mileva, N., & Martínez Mediano, K. (2008). The effect of adaptive performance support system on learning achievements of students. International Journal of Continuing Engineering Education and Lifelong Learning, 18 (3), 351-365

  6. Gender, Geographic Locations, Achievement Goals and Academic Performance of Secondary School Students from Borno State, Nigeria

    Science.gov (United States)

    Musa, Alice K.J.

    2013-01-01

    The paper examined gender, geography location, achievement goals and academic performance of senior secondary school students in Borno State, Nigeria. The sample consists of 827 students from 18 public boarding secondary schools across South and North of Borno State: 414 (50.1 per cent) males and 413 (49.9 per cent) are females; 414 (50.1 per…

  7. Teaching to the Tails: Teacher Performance Pay and the Distribution of Student Achievement

    Science.gov (United States)

    Loyalka, Prashant; Sylvia, Sean; Liu, Chengfang; Chu, James; Rozelle, Scott

    2015-01-01

    Growing evidence suggests that teachers in developing countries often have weak or misaligned incentives for improving student outcomes. In response, policymakers and researchers have proposed performance pay as a way to improve student outcomes by tying concrete measures like achievement scores to teacher pay. While evidence from randomized…

  8. On the achievable performance using variable geometry active secondary suspension systems in commercial vehicles

    NARCIS (Netherlands)

    Evers, W.J.; Besselink, I.G.M.; Teerhuis, A.P.; Nijmeijer, H.

    2011-01-01

    There is a need to further improve driver comfort in commercial vehicles. The variable geometry active suspension offers an interesting option to achieve this in an energy efficient way. However, the optimal control strategy and the overal performance potential remains unclear. The aim of this paper

  9. The Influence of Overt Practice, Achievement Level, and Explanatory Style on Calibration Accuracy and Performance

    Science.gov (United States)

    Bol, Linda; Hacker, Douglas J.; O'Shea, Patrick; Allen, Dwight

    2005-01-01

    The authors measured the influence of overt calibration practice, achievement level, and explanatory style on calibration accuracy and exam performance. Students (N = 356) were randomly assigned to either an overt practice or no-practice condition. Students in the overt practice condition made predictions and postdictions about their performance…

  10. Stability analysis of stagnation-point flow over a stretching/shrinking sheet

    Directory of Open Access Journals (Sweden)

    I. S. Awaludin

    2016-04-01

    Full Text Available The stagnation point flow over a linearly stretching or shrinking sheet is considered in the present study. The transformed ordinary differential equations are solved numerically. Dual solutions are possible for the shrinking case, while the solution is unique for the stretching case. For the shrinking case, a linear temporal stability analysis is performed to determine which one of the solution is stable and thus physically reliable.

  11. Modeling and simulation of axisymmetric stagnation flames

    Science.gov (United States)

    Sone, Kazuo

    Laminar flame modeling is an important element in turbulent combustion research. The accuracy of a turbulent combustion model is highly dependent upon our understanding of laminar flames and their behavior in many situations. How much we understand combustion can only be measured by how well the model describes and predicts combustion phenomena. One of the most commonly used methane combustion models is GRI-Mech 3.0. However, how well the model describes the reacting flow phenomena is still uncertain even after many attempts to validate the model or quantify uncertainties. In the present study, the behavior of laminar flames under different aerodynamic and thermodynamic conditions is studied numerically in a stagnation-flow configuration. In order to make such a numerical study possible, the spectral element method is reformulated to accommodate the large density variations in methane reacting flows. In addition, a new axisymmetric basis function set for the spectral element method that satisfies the correct behavior near the axis is developed, and efficient integration techniques are developed to accurately model axisymmetric reacting flow within a reasonable amount of computational time. The numerical method is implemented using an object-oriented programming technique, and the resulting computer program is verified with several different verification methods. The present study then shows variances with the commonly used GRI-Mech 3.0 chemical kinetics model through a direct simulation of laboratory flames that allows direct comparison to experimental data. It is shown that the methane combustion model based on GRI-Mech 3.0 works well for methane-air mixtures near stoichiometry. However, GRI-Mech 3.0 leads to an overprediction of laminar flame speed for lean mixtures and an underprediction for rich mixtures. This result is slightly different from conclusion drawn in previous work, in which experimental data are compared with a one-dimensional numerical solutions

  12. ACHIEVING MATURITY (AND MEASURING PERFORMANCE THROUGH MODEL-BASED PROCESS IMPROVEMENT

    Directory of Open Access Journals (Sweden)

    Jose Marcelo Almeida Prado Cestari

    2013-08-01

    Full Text Available This paper presents the approach adopted by a software development unit in order to achieve the maturity level 3 of CMMI-DEV and therefore obtaining better performance. Through historical research and secondary data analysis of the organization, the paper intends to answer the following research question: "Could the adoption of maturity/best practices models bring better performance results to small and medium organizations?" Data and analysis conducted show that, besides the creation of indicator’s based management, there are some quantitative performance improvements in indicators such as: Schedule Deviation Rate, Effort Deviation Rate, Percent Late Delivery, Productivity Deviation and Internal Rework Rate

  13. The honeymoon effect in job performance - Temporal increases in the predictive power of achievement motivation

    Science.gov (United States)

    Helmreich, Robert L.; Sawin, Linda L.; Carsrud, Alan L.

    1986-01-01

    Correlations between a job performance criterion and personality measures reflecting achievement motivation and an interpersonal orientation were examined at three points in time after completion of job training for a sample of airline reservations agents. Although correlations between the personality predictors and performance were small and nonsignificant for the 3-month period after beginning the job, by the end of six and eight months a number of significant relationships had emerged. Implications for the utility of personality measures in selection and performance prediction are discussed.

  14. A physical education trial improves adolescents' cognitive performance and academic achievement: the EDUFIT study.

    Science.gov (United States)

    Ardoy, D N; Fernández-Rodríguez, J M; Jiménez-Pavón, D; Castillo, R; Ruiz, J R; Ortega, F B

    2014-02-01

    To analyze the effects of an intervention focused on increasing the time and intensity of Physical Education (PE), on adolescents' cognitive performance and academic achievement. A 4-month group-randomized controlled trial was conducted in 67 adolescents from South-East Spain, 2007. Three classes were randomly allocated into control group (CG), experimental group 1 (EG1) and experimental group 2 (EG2). CG received usual PE (two sessions/week), EG1 received four PE sessions/week and EG2 received four PE sessions/week of high intensity. Cognitive performance (non-verbal and verbal ability, abstract reasoning, spatial ability, verbal reasoning and numerical ability) was assessed by the Spanish Overall and Factorial Intelligence Test, and academic achievement by school grades. All the cognitive performance variables, except verbal reasoning, increased more in EG2 than in CG (all P improved more than EG1, without differences between EG1 and CG. Increased PE can benefit cognitive performance and academic achievement. This study contributes to the current knowledge by suggesting that the intensity of PE sessions might play a role in the positive effect of physical activity on cognition and academic success. Future studies involving larger sample sizes should confirm or contrast these preliminary findings. PMID:23826633

  15. Response of air stagnation frequency to anthropogenically enhanced radiative forcing.

    Science.gov (United States)

    Horton, Daniel E; Harshvardhan; Diffenbaugh, Noah S

    2012-01-01

    Stagnant atmospheric conditions can lead to hazardous air quality by allowing ozone and particulate matter to accumulate and persist in the near-surface environment. By changing atmospheric circulation and precipitation patterns, global warming could alter the meteorological factors that regulate air stagnation frequency. We analyze the response of the National Climatic Data Center (NCDC) Air Stagnation Index (ASI) to anthropogenically enhanced radiative forcing using global climate model projections of late-21(st) century climate change (SRES A1B scenario). Our results indicate that the atmospheric conditions over the highly populated, highly industrialized regions of the eastern United States, Mediterranean Europe, and eastern China are particularly sensitive to global warming, with the occurrence of stagnant conditions projected to increase 12-to-25% relative to late-20(th) century stagnation frequencies (3-18+ days/year). Changes in the position/strength of the polar jet, in the occurrence of light surface winds, and in the number of precipitation-free days all contribute to more frequent late-21(st) century air mass stagnation over these high-population regions. In addition, we find substantial inter-model spread in the simulated response of stagnation conditions over some regions using either native or bias corrected global climate model simulations, suggesting that changes in the atmospheric circulation and/or the distribution of precipitation represent important sources of uncertainty in the response of air quality to global warming. PMID:23284587

  16. Average Minimum Transmit Power to achieve SINR Targets: Performance Comparison of Various User Selection Algorithms

    CERN Document Server

    Salim, Umer

    2010-01-01

    In multi-user communication from one base station (BS) to multiple users, the problem of minimizing the transmit power to achieve some target guaranteed performance (rates) at users has been well investigated in the literature. Similarly various user selection algorithms have been proposed and analyzed when the BS has to transmit to a subset of the users in the system, mostly for the objective of the sum rate maximization. We study the joint problem of minimizing the transmit power at the BS to achieve specific signal-to-interference-and-noise ratio (SINR) targets at users in conjunction with user scheduling. The general analytical results for the average transmit power required to meet guaranteed performance at the users' side are difficult to obtain even without user selection due to joint optimization required over beamforming vectors and power allocation scalars. We study the transmit power minimization problem with various user selection algorithms, namely semi-orthogonal user selection (SUS), norm-based...

  17. Relationship of Mathematics Olympiad Performance of Gifted Students with IQ and Mathematics Achievement

    OpenAIRE

    BORAN, Ali İhsan; Kübra AÇIKGÜL; KÖKSAL, Mustafa Serdar

    2015-01-01

    The purpose of this study is to investigate relationship of mathematics Olympiad (analysis-algebra and geometry) scores of gifted students with IQ scores (verbal, performance and general) and mathematics achievement scores of the gifted students. Study group of the study included 64 gifted students (27 girls and 37 boys) who took courses from one Science and Art Center. Data of study involved scores of the participants on mathematics Olympiad exam, WISC-R test and school mathematics achieveme...

  18. AN ENERGY MODEL FOR ACHIEVING HIGH PERFORMANCE BURST TRANSMISSION IN OBCS NETWORKS

    OpenAIRE

    Renuka, R.; Kavitha, V.

    2013-01-01

    Optical burst switching is a promising solution for all optical WDM networks. It combines the benefits of optical circuit switching and optical packet switching. In OBS, the user data is collected at the edge of the network, sorted based on the destination address and grouped into variable size bursts. The OBS framework has been widely used in past years, for recent work use Optical Burst Chain switching (OBCS) to achieve high performance. Here switching unit is burst chain it consist of non-...

  19. Relationships among multiple intelligences, motor performance and academic achievement in secondary school children

    OpenAIRE

    Ruiz Perez, Luis Miguel; Palomo Nieto, Miriam; Ramon Otero, Irene; Ruiz Amengual, Aixa; Navia Manzano, José Antonio

    2014-01-01

    This study examines the relationships between multiple intelligences, academic achievement and motor performance in a group of secondary school children. Four hundred and eighty schoolchildren participated in this study (171 female and 309 male) with an average age of 13.33 years (SD: 1.41). The Revised self-efficacy Inventory for Multiple Intelligences (IAIM-R) and the motor test Sportcomp were applied, and the average results of the academic year they had made were obtained. The analysis of...

  20. Relationship of Mathematics Olympiad Performance of Gifted Students with IQ and Mathematics Achievement

    Directory of Open Access Journals (Sweden)

    Ali İhsan BORAN

    2015-04-01

    Full Text Available The purpose of this study is to investigate relationship of mathematics Olympiad (analysis-algebra and geometry scores of gifted students with IQ scores (verbal, performance and general and mathematics achievement scores of the gifted students. Study group of the study included 64 gifted students (27 girls and 37 boys who took courses from one Science and Art Center. Data of study involved scores of the participants on mathematics Olympiad exam, WISC-R test and school mathematics achievement. For analysis of the data Pearson correlation analysis, Spearman correlation analysis, independent groups’ t-test and Mann Whitney U test were utilized. The findings showed that there was no significant relationship between the Olympiad scores on analysis-algebra and geometry and IQ scores (general, performance and verbal. But the Olympiad scores on analysis-algebra and geometry factors were significantly related to school mathematics achievement. Comparing IQ scores of highest and lowest scorer groups on the Olympiad scores showed that there were no significant differences between IQ scores (general, performance and verbal of the groups. However school mathematics scores of the participants significantly differed in terms of groups determined based on analysis-algebra and geometry scores.

  1. AN ENERGY MODEL FOR ACHIEVING HIGH PERFORMANCE BURST TRANSMISSION IN OBCS NETWORKS

    Directory of Open Access Journals (Sweden)

    R.RENUKA

    2013-04-01

    Full Text Available Optical burst switching is a promising solution for all optical WDM networks. It combines the benefits of optical circuit switching and optical packet switching. In OBS, the user data is collected at the edge of the network, sorted based on the destination address and grouped into variable size bursts. The OBS framework has been widely used in past years, for recent work use Optical Burst Chain switching (OBCS to achieve high performance. Here switching unit is burst chain it consist of non-periodic bursts in one wavelength. We present extensive simulation result for throughput, delay and energy to demonstrate its superior performance over OBS networks.

  2. Achieving High Performance Distributed System: Using Grid, Cluster and Cloud Computing

    Directory of Open Access Journals (Sweden)

    Sunil Kr Singh

    2015-02-01

    Full Text Available To increase the efficiency of any task, we require a system that would provide high performance along with flexibilities and cost efficiencies for user. Distributed computing, as we are all aware, has become very popular over the past decade. Distributed computing has three major types, namely, cluster, grid and cloud. In order to develop a high performance distributed system, we need to utilize all the above mentioned three types of computing. In this paper, we shall first have an introduction of all the three types of distributed computing. Subsequently examining them we shall explore trends in computing and green sustainable computing to enhance the performance of a distributed system. Finally presenting the future scope, we conclude the paper suggesting a path to achieve a Green high performance distributed system using cluster, grid and cloud computing

  3. Theoretical study on a solar collector loop during stagnation

    DEFF Research Database (Denmark)

    Chen, Ziqian; Dragsted, Janne; Furbo, Simon;

    2010-01-01

    A mathematical model simulating the stagnation behavior of a pressurized solar collector loop with solar collectors with a good emptying behavior is developed. Based on the pre-pressure of the expansion vessel, the system filling pressure of the solar collector loop and the design of the solar...... collector loop, the mass of the fluid flowing into the pressurized expansion vessel and the pressures at the top part and at the bottom part of the solar collector loop during stagnation for the solar collector loop are calculated. The theoretically calculated results are compared with experimental results....... There is a good agreement between calculations and measurements. The developed simulation model is therefore suitable to determine the behavior of solar collector loops during stagnation....

  4. Theoretical study on a solar collector loop during stagnation

    DEFF Research Database (Denmark)

    Chen, Ziqian; Dragsted, Janne; Furbo, Simon;

    A mathematical model simulating the stagnation behavior of a pressurized solar collector loop with solar collectors with a good emptying behavior is developed. Based on the pre-pressure of the expansion vessel, the system filling pressure of the solar collector loop and the design of the solar...... collector loop, the mass of the fluid flowing into the pressurized expansion vessel and the pressures at the top part and at the bottom part of the solar collector loop during stagnation for the solar collector loop are calculated. The theoretically calculated results are compared with experimental results....... There is a good agreement between calculations and measurements. The developed simulation model is therefore suitable to determine the behavior of solar collector loops during stagnation....

  5. Behavior of a solar collector loop during stagnation

    DEFF Research Database (Denmark)

    Chen, Ziqian; Dragsted, Janne; Furbo, Simon;

    2015-01-01

    A mathematical model simulating the emptying behavior of a pressurized solar collector loop with solar collectors with a good emptying behavior is developed and validated with measured data. The calculated results are in good agreement with the measured results. The developed simulation model...... is therefore suitable to determine the behavior of a solar collector loop during stagnation. A volume ratio R, which is the ratio of the volume of the vapour in the upper pipes of the solar collector loop during stagnation and the fluid content of solar collectors, is introduced to determine the mass...... of the collector fluid pushed into the expansion vessel during stagnation, Min. A correlation function for the mass Min and the volume ratio R for solar collector loops is obtained. The function can be used to determine a suitable size of expansion vessels for solar collector loops....

  6. The Problem: Low-Achieving Districts and Low-Performing Boards

    Directory of Open Access Journals (Sweden)

    David E. Lee

    2014-10-01

    Full Text Available Effective school districts maintain superintendent and school board collegiality which can foster success and connectedness among members. Delagardelle and Alsbury (2008 found that superintendents and board members are not consistent in their perceptions about the work the board does, and Glass (2007 found that states do not require boards to undergo evaluation for effectiveness. In the current study, 115 board meetings were observed using the School Board Video Project (SBVP survey, which was created in 2012 by researchers to uncover school board meetings’ effectiveness. MANOVA, Univariate ANOVA, and Pearson Chi-Square test results revealed significant differences between low-, medium-, and high-performing districts’ school board meetings. Evidence indicated that low-performing districts’ board meetings were: less orderly; had less time spent on student achievement; lacked respectful and attentive engagement across speakers; had board meeting members who seemed to advance their own agenda; had less effective working relationships among the governance team; had fewer board members who relied on the superintendent for advice and input; had one member, other than the board president, stand out for taking excessive time during meetings; and did not focus on policy items as much as high- and medium-performing school districts. The research concluded that more school board members from low-performing districts needed training to improve their effectiveness. Furthermore, highly refined and target-enhanced school board training programs might lead to lasting governance success and more effective teaming that could improve district, and ultimately, student achievement.

  7. Pressure and temperature development in solar heating system during stagnation

    DEFF Research Database (Denmark)

    Dragsted, Janne; Furbo, Simon; Chen, Ziqian;

    2010-01-01

    This paper presents an investigation of stagnation in solar collectors and the effects it will have on the collector loop. At a laboratory test stand at the Technical University of Denmark, a pressurized solar collector loop was designed to test different numbers of collectors and different designs...... of the pipes of the solar collector loop. During the investigation the pre-pressure of the expansion vessel and system filling pressure was changed. The investigations showed that a large pressurised expansion vessel will protect the collector loop from critically high temperatures as long as the solar...... collectors have a good emptying behaviour and the circulation pump is turned off during stagnation....

  8. Unsteady Reversed Stagnation-Point Flow over a Flat Plate

    CERN Document Server

    Sin, Vai Kuong

    2013-01-01

    This paper investigates the nature of the development of two-dimensional laminar flow of an incompressible fluid at the reversed stagnation-point. ". In this study, we revisit the problem of reversed stagnation-point flow over a flat plate. Proudman and Johnson (1962) first studied the flow and obtained an asymptotic solution by neglecting the viscous terms. This is no true in neglecting the viscous terms within the total flow field. In particular it is pointed out that for a plate impulsively accelerated from rest to a constant velocity V0 that a similarity solution to the self-similar ODE is obtained which is noteworthy completely analytical.

  9. Numerical Investigation of Nonisothermal Reversed Stagnation-point Flow

    CERN Document Server

    Kit, Chio Chon

    2013-01-01

    This thesis investigates the nature of the development of two-dimensional laminar nonisothermal flow of an incompressible fluid close to the reversed stagnation-point. Proudman and Johnson (1962) \\cite{proudman1962boundary} first studied the flow and obtained an asymptotic solution by neglecting the viscous terms. This is not practice in neglecting the viscous terms within the total flow field. Viscous terms in this analysis are now included, and two-dimensional nonisothermal reversed stagnation-point flow is investigated by solving the Navier-Stokes equations coupled to energy equation.

  10. Understanding the stagnation and burn of implosions on NIF

    Science.gov (United States)

    Kilkenny, J. D.; Caggiano, J. A.; Hatarik, R.; Knauer, J. P.; Sayre, D. B.; Spears, B. K.; Weber, S. V.; Yeamans, C. B.; Cerjan, C. J.; Divol, L.; Eckart, M. J.; Glebov, V. Yu; Herrmann, H. W.; Le Pape, S.; Munro, D. H.; Grim, G. P.; Jones, O. S.; Berzak-Hopkins, L.; Gatu-Johnson, M.; Mackinnon, A. J.; Meezan, N. B.; Casey, D. T.; Frenje, J. A.; Mcnaney, J. M.; Petrasso, R.; Rinderknecht, H.; Stoeffl, W.; Zylstra, A. B.

    2016-03-01

    An improved the set of nuclear diagnostics on NIF measures the properties of the stagnation plasma of implosions, including the drift velocity, areal density (ρr) anisotropy and carbon ρr of the compressed core. Two types of deuterium-tritium (DT) gas filled targets are imploded by shaped x-ray pulses, producing stagnated and burning DT cores of radial convergence (Cr) ∼ 5 or ∼20. Comparison with two-dimensional modeling with inner and outer surface mix shows good agreement with nuclear measurements.

  11. Social jetlag, academic achievement and cognitive performance: Understanding gender/sex differences.

    Science.gov (United States)

    Díaz-Morales, Juan F; Escribano, Cristina

    2015-01-01

    Adolescents in high school suffer from circadian misalignment, undersleeping on weekdays and oversleeping on weekends. Since high schools usually impose early schedules, adolescents suffer from permanent social jetlag (SJL) and thus are a suitable population to study the effects of SJL on both academic and cognitive performance. In this study, 796 adolescents aged 12-16 years reported information about their sleep habits, morningness-eveningness (M-E), cognitive abilities and grade point average (GPA). Time in bed on both weekdays and weekends was not related to cognitive abilities, and only time in bed on weekdays was related to academic achievement. SJL was negatively related to academic achievement, cognitive abilities (except for vocabulary and verbal fluency abilities) and general cognitive ability (g), whereas M-E was slightly positively related to academic achievement and marginally negatively related to inductive reasoning. Results separated by sex/gender indicated that SJL may be more detrimental to girls' performance, as it was negatively related to a greater number of cognitive abilities and GPA.

  12. THE IMPACT OF EMPLOYEE EMPOWERMENT ON ACHIEVEMENT MOTIVATION AND CONTEXTUAL PERFORMANCE OF EMPLOYEE: A CASE BANKING SECTOR IN PAKISTAN

    OpenAIRE

    Mudassar Ghafoor; Sadaf Amjad Gillani; Maria Zafar Cheema; Azeem, M.

    2013-01-01

    The rationale of study is to investigate the effects of employee empowerment on achievement motivation and contextual performance of employees. Responses of employees in Public and private banks have been analyzed by using regressions analysis. The results of study show the positive impact of employee empowerment of achievement motivation and contextual performance of employees. It implies that employee empowerment is important for achievement motivation and ultimate performance for employees...

  13. Achieving excellence in human performance through leadership, education, and training in nuclear power industry

    International Nuclear Information System (INIS)

    Full text: In order to achieve and maintain high levels of safety and productivity, nuclear power plants are required to be staffed with an adequate number of highly qualified and experienced personnel who are duly aware of the technical and administrative requirements for safety and are motivated to adopt a positive attitude to safety, as an element of safety culture. To establish and maintain a high level of human performance, appropriate education and training programmes should be in place and kept under constant review to ensure their relevance. As the nuclear power industry continues to be challenged by increasing safety requirements, a high level of competition and decreasing budgets, it becomes more important than ever to maintain excellence in human performance and ensure that NPP personnel training provides a value to the organization. Nuclear industry managers and supervisors bear the primary responsibility to assure that people perform their jobs safely and effectively. Training personnel must be responsive to the needs of the organization, working hand-in-hand with line managers and supervisors to ensure that human performance improvement needs are properly analyzed, and that training as well as other appropriate interventions are developed and implemented in the most effective and efficient way possible. The International Atomic Energy Agency together with its Member States has provided for coordinated information exchange and developed guidance on methods and practices to identify and improve the effectiveness NPP personnel training. This has resulted in: plant performance improvements, improved human performance, meeting goals and objectives of the business (quality, safety, productivity), and more effective training programs. This article describes the IAEA activities and achievements in the subject area for systematically understanding and improving human performance in nuclear power industry. The article also describes cooperation programmes

  14. Occurrence and persistence of future atmospheric stagnation events

    Science.gov (United States)

    Horton, Daniel E.; Skinner, Christopher B.; Singh, Deepti; Diffenbaugh, Noah S.

    2014-08-01

    Poor air quality causes an estimated 2.6-4.4 million premature deaths per year. Hazardous conditions form when meteorological components allow the accumulation of pollutants in the near-surface atmosphere. Global-warming-driven changes to atmospheric circulation and the hydrological cycle are expected to alter the meteorological components that control pollutant build-up and dispersal, but the magnitude, direction, geographic footprint and public health impact of this alteration remain unclear. We used an air stagnation index and an ensemble of bias-corrected climate model simulations to quantify the response of stagnation occurrence and persistence to global warming. Our analysis projects increases in stagnation occurrence that cover 55% of the current global population, with areas of increase affecting ten times more people than areas of decrease. By the late twenty-first century, robust increases of up to 40 days per year are projected throughout the majority of the tropics and subtropics, as well as within isolated mid-latitude regions. Potential impacts over India, Mexico and the western US are particularly acute owing to the intersection of large populations and increases in the persistence of stagnation events, including those of extreme duration. These results indicate that anthropogenic climate change is likely to alter the level of pollutant management required to meet future air quality targets.

  15. Generativity-Stagnation: Development of a Status Model.

    Science.gov (United States)

    Bradley, Cheryl L.

    1997-01-01

    Reviews theoretical and empirical developments in Erik Erikson's construct of generativity-stagnation. Presents a five-category model describing styles of resolving the issue using combinations of level of involvement or active concern for the growth of self and others; and level of inclusivity or scope of caregiving concern. Discusses model in…

  16. When structures become shackles: stagnation and dynamics in international lawmaking

    NARCIS (Netherlands)

    Pauwelyn, Joost; Wessel, Ramses A.; Wouters, Jan

    2014-01-01

    Formal international law is stagnating in terms both of quantity and quality. It is increasingly superseded by ‘informal international lawmaking’ involving new actors, new processes, and new outputs, in fields ranging from finance and health to internet regulation and the environment. On many occasi

  17. Modeling ion interpenetration, stagnation, and thermalization in colliding plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Jones, M.E.; Winske, D.; Goldman, S.R.; Kopp, R.A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Rogatchev, V.G.; Belkov, S.A.; Gasparyan, P.D.; Dolgoleva, G.V.; Zhidkov, N.V.; Ivanov, N.V.; Kochubej, Y.K.; Nasyrov, G.F.; Pavlovskii, V.A.; Smirnov, V.V.; Romanov, Y.A. [All Russian Scientific Research Institute of Experimental Physics, Sarov (Arzamas 16), Nizhniy Novgorod Region, 607200 (Russia)

    1996-03-01

    Ion interpenetration, stagnation, and energization processes are studied in colliding laser-produced plasma configurations relevant to Trident [R. G. Watt, Rev. Sci. Instrum. {bold 64}, 1770 (1993)] experiments using four different numerical methods: one-dimensional Monte Carlo and Lagrangian multifluid codes, and one- and two-dimensional hybrid (particle ions, fluid electrons) and single-fluid Lagrangian codes. Results from the four methodologies are compared for plasmas generated with gold and deuterated polyethylene (CD{sub 2}) targets. Overall, the various codes give similar results concerning the initial expansion of the plasmas and their collisional interaction, the degree of stagnation, stagnation time, and amount of ion thermalization for gold targets, while multispecies techniques indicate a much softer stagnation for CD{sub 2} plasmas than the single-fluid model. Variations in the results of the calculations due to somewhat different initializations and parameters, as well as to different physics in the codes, are discussed. {copyright} {ital 1996 American Institute of Physics.}

  18. Stability of stagnation via an expanding accretion shock wave

    Science.gov (United States)

    Velikovich, A. L.; Murakami, M.; Taylor, B. D.; Giuliani, J. L.; Zalesak, S. T.; Iwamoto, Y.

    2016-05-01

    Stagnation of a cold plasma streaming to the center or axis of symmetry via an expanding accretion shock wave is ubiquitous in inertial confinement fusion (ICF) and high-energy-density plasma physics, the examples ranging from plasma flows in x-ray-generating Z pinches [Maron et al., Phys. Rev. Lett. 111, 035001 (2013)] to the experiments in support of the recently suggested concept of impact ignition in ICF [Azechi et al., Phys. Rev. Lett. 102, 235002 (2009); Murakami et al., Nucl. Fusion 54, 054007 (2014)]. Some experimental evidence indicates that stagnation via an expanding shock wave is stable, but its stability has never been studied theoretically. We present such analysis for the stagnation that does not involve a rarefaction wave behind the expanding shock front and is described by the classic ideal-gas Noh solution in spherical and cylindrical geometry. In either case, the stagnated flow has been demonstrated to be stable, initial perturbations exhibiting a power-law, oscillatory or monotonic, decay with time for all the eigenmodes. This conclusion has been supported by our simulations done both on a Cartesian grid and on a curvilinear grid in spherical coordinates. Dispersion equation determining the eigenvalues of the problem and explicit formulas for the eigenfunction profiles corresponding to these eigenvalues are presented, making it possible to use the theory for hydrocode verification in two and three dimensions.

  19. Stability of stagnation via an expanding accretion shock wave

    CERN Document Server

    Velikovich, A L; Taylor, B D; Giuliani, J L; Zalesak, S T; Iwamoto, Y

    2016-01-01

    Stagnation of a cold plasma streaming to the center or axis of symmetry via an expanding accretion shock wave is ubiquitous in inertial confinement fusion (ICF) and high-energy-density plasma physics, the examples ranging from plasma flows in x-ray-generating Z pinches [Y. Maron et al., Phys. Rev. Lett. 111, 035001 (2013)] to the experiments in support of the recently suggested concept of impact ignition in ICF [H. Azechi et al., Phys. Rev. Lett. 102, 235002 (2009); M. Murakami et al., Nucl. Fusion 54, 054007 (2014)]. Some experimental evidence indicates that stagnation via an expanding shock wave is stable, but its stability has never been studied theoretically. We present such analysis for the stagnation that does not involve a rarefaction wave behind the expanding shock front and is described by the classic ideal-gas Noh solution in spherical and cylindrical geometry. In either case the stagnated flow has been demonstrated to be stable, initial perturbations exhibiting a power-law, oscillatory or monotonic...

  20. Achieving High Performance in AC-Field Driven Organic Light Sources.

    Science.gov (United States)

    Xu, Junwei; Carroll, David L; Smith, Gregory M; Dun, Chaochao; Cui, Yue

    2016-04-11

    Charge balance in organic light emitting structures is essential to simultaneously achieving high brightness and high efficiency. In DC-driven organic light emitting devices (OLEDs), this is relatively straight forward. However, in the newly emerging, capacitive, field-activated AC-driven organic devices, charge balance can be a challenge. In this work we introduce the concept of gating the compensation charge in AC-driven organic devices and demonstrate that this can result in exceptional increases in device performance. To do this we replace the insulator layer in a typical field-activated organic light emitting device with a nanostructured, wide band gap semiconductor layer. This layer acts as a gate between the emitter layer and the voltage contact. Time resolved device characterization shows that, at high-frequencies (over 40 kHz), the semiconductor layer allows for charge accumulation in the forward bias, light generating part of the AC cycle and charge compensation in the negative, quiescent part of the AC cycle. Such gated AC organic devices can achieve a non-output coupled luminance of 25,900 cd/m(2) with power efficiencies that exceed both the insulator-based AC devices and OLEDs using the same emitters. This work clearly demonstrates that by realizing balanced management of charge, AC-driven organic light emitting devices may well be able to rival today's OLEDs in performance.

  1. Achieving High Performance in AC-Field Driven Organic Light Sources

    Science.gov (United States)

    Xu, Junwei; Carroll, David L.; Smith, Gregory M.; Dun, Chaochao; Cui, Yue

    2016-04-01

    Charge balance in organic light emitting structures is essential to simultaneously achieving high brightness and high efficiency. In DC-driven organic light emitting devices (OLEDs), this is relatively straight forward. However, in the newly emerging, capacitive, field-activated AC-driven organic devices, charge balance can be a challenge. In this work we introduce the concept of gating the compensation charge in AC-driven organic devices and demonstrate that this can result in exceptional increases in device performance. To do this we replace the insulator layer in a typical field-activated organic light emitting device with a nanostructured, wide band gap semiconductor layer. This layer acts as a gate between the emitter layer and the voltage contact. Time resolved device characterization shows that, at high-frequencies (over 40 kHz), the semiconductor layer allows for charge accumulation in the forward bias, light generating part of the AC cycle and charge compensation in the negative, quiescent part of the AC cycle. Such gated AC organic devices can achieve a non-output coupled luminance of 25,900 cd/m2 with power efficiencies that exceed both the insulator-based AC devices and OLEDs using the same emitters. This work clearly demonstrates that by realizing balanced management of charge, AC-driven organic light emitting devices may well be able to rival today’s OLEDs in performance.

  2. Corporate Governance as a Crucial Factor in Achieving Sustainable Corporate Performance

    Directory of Open Access Journals (Sweden)

    Julija Bistrova

    2014-06-01

    Full Text Available In the developed stock markets the corporate governance aspect is crucial in the stock portfolio selection process for investor seeking to achieve shareholder value sustainability. In the emerging markets the importance of the corporate governance role just starts to be realized by the investors and by the corporate managers. The present research, looking at the stock performance leaders and laggards, analyzes whether the corporate governance system matters to achieve long-term shareholder value within the Central and Eastern European stock markets universe. Corporate governance quality was assessed and compared among the out- and underperformers. The financial results plausibility and the ownership structure were considered as well. Additionally, the authors analyzed whether the quality of corporate governance influences the economic performance of the company. The obtained results provide the proof that the corporate governance does matter as the market outperformers have above average corporate governance quality and provide trustworthy financial results more often than the underperforming companies. Besides, well-governed companies are also able to deliver more attractive financial results.

  3. High-Achieving High School Students and Not so High-Achieving College Students: A Look at Lack of Self-Control, Academic Ability, and Performance in College

    Science.gov (United States)

    Honken, Nora B.; Ralston, Patricia A. S.

    2013-01-01

    This study investigated the relationship among lack of self-control, academic ability, and academic performance for a cohort of freshman engineering students who were, with a few exceptions, extremely high achievers in high school. Structural equation modeling analysis led to the conclusion that lack of self-control in high school, as measured by…

  4. The role of locus of control and achievement motivation in the work performance of black managers

    Directory of Open Access Journals (Sweden)

    A. C. Bothma

    1997-06-01

    Full Text Available The primary objective of this study was to predict the work performance of Black managers by using three measures of Locus of Control and five measures of Achievement Motivation. Work performance was assessed by superiors with the aid of the Performance Appraisal Questionnaire of Schepers (1994 which yields three scores, viz, Work Performance, Creativity/Initiative and Management Skills. The sample comprised 102 Black male employees in supervisory and more senior positions in a diversified and geographically dispersed chemical company. In analysing the data, the three sets of measures were intercorrelated and subjected to a factor analysis. Three factors were identified; amongst others a factor representing work performance. A composite score was accordingly computed which served as the criterion measure in a regression analysis. Furthermore/ a canonical correlation procedure was used to maximise the correlation between the predictor variables and the dependent variables. Two statistically significant canonical correlations were obtained. It was found that both the Locus of Control Inventory and the Achievement Motivation Questionnaire can be used as predictors of work performance as assessed by means of the Performance Appraisal Questionnaire (PA. Opsomming Die primêre doelwit van hierdie studie was om die werkverrigting van Swart bestuurders te voorspel deur gebruik te maak van drie metings van Lokus van Beheer en vyf metings van Prestasiemotivering. Werkverrigting is deur bogeskiktes met behulp van die Prestasiebeoordelingsvraelys van Schepers (1994 beoordeel, wat drie tellings lewer, naamlik Werkverigting, Inisiatief/Kreatiwiteit en Bestuursvaardighede. Die steekproef het uit 102 Swart manlike werknemers in toesighoudende en meer senior posisies in 'n gediversifiseerde en geografies verspreide chemiese maatskappy bestaan. In die ontleding van die data is die drie stelle metings geïterkorreleer en aan 'n faktorontleding onderwerp. Drie

  5. Achieving realistic performance and decison-making capabilities in computer-generated air forces

    Science.gov (United States)

    Banks, Sheila B.; Stytz, Martin R.; Santos, Eugene, Jr.; Zurita, Vincent B.; Benslay, James L., Jr.

    1997-07-01

    For a computer-generated force (CGF) system to be useful in training environments, it must be able to operate at multiple skill levels, exhibit competency at assigned missions, and comply with current doctrine. Because of the rapid rate of change in distributed interactive simulation (DIS) and the expanding set of performance objectives for any computer- generated force, the system must also be modifiable at reasonable cost and incorporate mechanisms for learning. Therefore, CGF applications must have adaptable decision mechanisms and behaviors and perform automated incorporation of past reasoning and experience into its decision process. The CGF must also possess multiple skill levels for classes of entities, gracefully degrade its reasoning capability in response to system stress, possess an expandable modular knowledge structure, and perform adaptive mission planning. Furthermore, correctly performing individual entity behaviors is not sufficient. Issues related to complex inter-entity behavioral interactions, such as the need to maintain formation and share information, must also be considered. The CGF must also be able to acceptably respond to unforeseen circumstances and be able to make decisions in spite of uncertain information. Because of the need for increased complexity in the virtual battlespace, the CGF should exhibit complex, realistic behavior patterns within the battlespace. To achieve these necessary capabilities, an extensible software architecture, an expandable knowledge base, and an adaptable decision making mechanism are required. Our lab has addressed these issues in detail. The resulting DIS-compliant system is called the automated wingman (AW). The AW is based on fuzzy logic, the common object database (CODB) software architecture, and a hierarchical knowledge structure. We describe the techniques we used to enable us to make progress toward a CGF entity that satisfies the requirements presented above. We present our design and

  6. Improvement in performance of DM plant, secondary systems for achieving chemistry performance indicator of KGS-3 and 4

    International Nuclear Information System (INIS)

    Kaiga Generating Station (KGS)-3 and 4 has two 220 MWe Pressurized Heavy Water Reactors. It uses Heavy water as moderator and coolant and DM (De-mineralized) water in secondary system for steam generation. Raw water for plant is taken from Kali River. Raw water is first treated in pretreatment plant and Dual media filter for turbidity removal. Chlorination is carried out for control of micro-organism. DM water is makeup to feed water which is the input to Steam Generator for production of steam for power generation. Continuous blow down through Boiler blow down (BBD) IX column is carried out to control Steam Generator (SG) chemistry. It was decided by Nuclear Power Corporation India Limited (NPCIL) management to calculate Chemistry Performance Indicator of KGS secondary system and it was found 2.6 which was much higher than Standard and best achievable value of 1.0. Detailed analysis was carried out and improvements required in DM plant, water treatment plant, BBD IX column, Steam Generator etc were identified and plan was made for improvement. Turbidity of filter water was brought below 2.0 NTU. Many changes were incorporated in DM plant. Regenerate concentration, regeneration levels and regeneration procedures were modified. Resin replacement frequencies were fixed and brine treatment of anion resin was started at regular interval. For DM water production two mixed resin columns in series were used in place of earlier one mixed resin column. By these modifications DM water Chloride, Sodium and Sulphate were brought <1.0 ppb from earlier 5-10 ppb. Regeneration procedure of BBD IX column were standardized. Service life of BBD IX column was fixed and was isolated from service before exhaustion. Design deficiencies of BBD IX column was rectified by applying innovative idea. Online sodium analyzer was installed in boiler blow down line. By implementing these improvements Chemistry Performance Indicator of both units were brought down to 1.0, which is standard and best

  7. A comprehensive approach to decipher biological computation to achieve next generation high-performance exascale computing.

    Energy Technology Data Exchange (ETDEWEB)

    James, Conrad D.; Schiess, Adrian B.; Howell, Jamie; Baca, Michael J.; Partridge, L. Donald; Finnegan, Patrick Sean; Wolfley, Steven L.; Dagel, Daryl James; Spahn, Olga Blum; Harper, Jason C.; Pohl, Kenneth Roy; Mickel, Patrick R.; Lohn, Andrew; Marinella, Matthew

    2013-10-01

    The human brain (volume=1200cm3) consumes 20W and is capable of performing > 10^16 operations/s. Current supercomputer technology has reached 1015 operations/s, yet it requires 1500m^3 and 3MW, giving the brain a 10^12 advantage in operations/s/W/cm^3. Thus, to reach exascale computation, two achievements are required: 1) improved understanding of computation in biological tissue, and 2) a paradigm shift towards neuromorphic computing where hardware circuits mimic properties of neural tissue. To address 1), we will interrogate corticostriatal networks in mouse brain tissue slices, specifically with regard to their frequency filtering capabilities as a function of input stimulus. To address 2), we will instantiate biological computing characteristics such as multi-bit storage into hardware devices with future computational and memory applications. Resistive memory devices will be modeled, designed, and fabricated in the MESA facility in consultation with our internal and external collaborators.

  8. Stagnation-point flow and heat transfer over an exponentially shrinking sheet: A stability analysis

    Science.gov (United States)

    Ismail, Nurul Syuhada; Arifin, Norihan Md.; Bachok, Norfifah; Mahiddin, Norhasimah

    2016-06-01

    Numerical solutions for the stagnation-point flow and heat transfer over an exponentially shrinking sheet have been investigated. The governing boundary layer equations are transformed into an ordinary differential equation using a non-similar transformation. By using the bvp4c solver in MATLAB, the results of the equations can be solved numerically. Numerical results indicate that in certain parameter, the non-unique solutions for the velocity and the temperature do exist. A linear stability analysis shows that only one solution is linearly stable otherwise is unstable. Then, the stability analysis is performed to identify which solution is stable between the two non-unique solutions.

  9. A Novel Hybrid MCDM Procedure for Achieving Aspired Earned Value Project Performance

    Directory of Open Access Journals (Sweden)

    Shou-Yan Chou

    2016-01-01

    Full Text Available A better-performing project gains more subsequent businesses. Many organizations worldwide apply an earned value management (EVM system to monitor and control their projects’ performance. However, a successful EVM application requires handling multiple interinfluenced criteria with feedback effects for decision-making and continuous improvements throughout the application life cycle. The conventional decision approaches assume that preferences between criteria are independent and put their focuses on decision-making. This study employs a hybrid multiple criteria decision-making (HMCDM method to devise a novel procedure to fulfil the deficiencies. The proposed procedure enables us to evaluate interinfluence effects and gap indices among criteria/dimensions/alternatives and then systemize the evaluation results in a context of influential network relation map (INRM. The INRM provides managers with visual information to find a route in making application decisions, while identifying critical gaps for continuous improvements. A numerical example is presented to illustrate the applicability of the proposed procedure. The results show that, by employing the HMCDM method, the proposed procedure can provide organizations with a foundation to ensure that the aspired EVM application outcomes are achieved at different levels within an organization.

  10. Magnetohydrodynamic stagnation point flow with a convective surface boundary condition

    Energy Technology Data Exchange (ETDEWEB)

    Jafar, Khamisah [Universiti Kebangsaan Malaysia, Bangi, Selangor (Malaysia). Faculty of Engineering and Built Environment; Ishak, Anuar; Nazar, Roslinda [Universiti Kebangsaan, Bangi, Selangor (Malaysia). School of Mathematical Sciences

    2011-08-15

    This study analyzes the steady laminar two-dimensional stagnation point flow and heat transfer of an incompressible viscous fluid impinging normal to a horizontal plate, with the bottom surface of the plate heated by convection from a hot fluid. A uniform magnetic field is applied in a direction normal to the flat plate, with a free stream velocity varying linearly with the distance from the stagnation point. The governing partial differential equations are first transformed into ordinary differential equations, before being solved numerically. The analysis includes the effects of the magnetic parameter, the Prandtl number, and the convective parameter on the heat transfer rate at the surface. Results showed that the heat transfer rate at the surface increases with increasing values of these quantities. (orig.)

  11. Spectroscopic study of z-pinch stagnation on Z.

    Energy Technology Data Exchange (ETDEWEB)

    Maron, Yitzhak (Weizmann Institute of Science); Weingarten, L. (Weizmann Institute of Science); Starobinets, A. (Weizmann Institute of Science); Fisher, V. (Weizmann Institute of Science); Jennings, Christopher A.; Ampleford, David J.; Bailey, James E.; Yu, Edmund P.; Bernshtam, V. (Weizmann Institute of Science); Cuneo, Michael Edward; Rochau, Gregory Alan; Coverdale, Christine Anne; Jones, Brent Manley; Hansen, Stephanie B.

    2010-11-01

    Fast z-pinches provide intense 1-10 keV photon energy radiation sources. Here, we analyze time-, space-, and spectrally-resolved {approx}2 keV K-shell emissions from Al (5% Mg) wire array implosions on Sandia's Z machine pulsed power driver. The stagnating plasma is modeled as three separate radial zones, and collisional-radiative modeling with radiation transport calculations are used to constrain the temperatures and densities in these regions, accounting for K-shell line opacity and Doppler effects. We discuss plasma conditions and dynamics at the onset of stagnation, and compare inferences from the atomic modeling to three-dimensional magneto-hydrodynamic simulations.

  12. Wage Stagnation? Fact Disclosure and Cross-Country Comparison

    OpenAIRE

    Chang-Ching Lin; Juin-Jen Chang; Shu-Shiuan Lu

    2014-01-01

    This paper sheds light on three important issues in the macroeconomics literature, which comes to a better understanding of Taiwan’s wage stagnation. First, we explore the trend of labor income shares, namely the labor income-output ratios, in Taiwan. This enables us to understand the distribution or tradeoff between labor and capital shares. Second, we calculate the correlation coefficients between real wages and gross domestic product (GDP) per capita, showing that whether Taiwan’s real wag...

  13. Acceleration, Stagnation and Crisis: the Role of Policies and Institutions

    OpenAIRE

    Jerzmanowski, Michal

    2011-01-01

    In this paper we study long run economic growth as a sequence of accelerations, slowdowns and crises, and estimate the role of institutions and macroeconomic policies in determining this sequence. We analyze the joint effect of policies and institutions on the frequency of the four growth regimes: stable growth, stagnation, crisis and miracle-like fast growth. The results confirm the importance of institutions for growth but also show that macro-policies; inflation, trade openness, size of go...

  14. The Long Italian Stagnation and the Welfare Effects of Outsourcing

    OpenAIRE

    Zotti, Jacopo

    2015-01-01

    The stagnation of the Italian economy over the last two decades is widely documented. During this period, the world economy has become highly integrated, and foreign outsourcing has become a standard practice for firms. While trade theory predicts benefits from the internationalization of production, Italy seems to have gained negligibly from it, or, rather to have lost. In a simple model, we show that this may be the case when markets are overregulated and competition policies are weak. We s...

  15. Dynamics and Stagnation in the Malthusain Epoch: Theory and Evidence

    OpenAIRE

    Quamrul Ashraf; Oded Galor

    2008-01-01

    This paper empirically tests the predictions of the Malthusian theory with respect to both population dynamics and income per capita stagnation in the pre-Industrial Revolution era. The theory suggests that improvements in technology during this period generated only temporary gains in income per capita, eventually leading to a larger but not richer population. Using exogenous cross-country variations in land productivity and the timing of the Neolithic Revolution, the analysis demonstrates t...

  16. Achieving numerical accuracy and high performance using recursive tile LU factorization with partial pivoting

    KAUST Repository

    Dongarra, Jack

    2013-09-18

    The LU factorization is an important numerical algorithm for solving systems of linear equations in science and engineering and is a characteristic of many dense linear algebra computations. For example, it has become the de facto numerical algorithm implemented within the LINPACK benchmark to rank the most powerful supercomputers in the world, collected by the TOP500 website. Multicore processors continue to present challenges to the development of fast and robust numerical software due to the increasing levels of hardware parallelism and widening gap between core and memory speeds. In this context, the difficulty in developing new algorithms for the scientific community resides in the combination of two goals: achieving high performance while maintaining the accuracy of the numerical algorithm. This paper proposes a new approach for computing the LU factorization in parallel on multicore architectures, which not only improves the overall performance but also sustains the numerical quality of the standard LU factorization algorithm with partial pivoting. While the update of the trailing submatrix is computationally intensive and highly parallel, the inherently problematic portion of the LU factorization is the panel factorization due to its memory-bound characteristic as well as the atomicity of selecting the appropriate pivots. Our approach uses a parallel fine-grained recursive formulation of the panel factorization step and implements the update of the trailing submatrix with the tile algorithm. Based on conflict-free partitioning of the data and lockless synchronization mechanisms, our implementation lets the overall computation flow naturally without contention. The dynamic runtime system called QUARK is then able to schedule tasks with heterogeneous granularities and to transparently introduce algorithmic lookahead. The performance results of our implementation are competitive compared to the currently available software packages and libraries. For example

  17. The Achievement Motivation-Performance Relationship as Moderated by Sex-Role Attitudes

    Science.gov (United States)

    Thurber, Steven

    1976-01-01

    The moderating effect of sex-role attitudes in relation to the predictive validity of Mehrabian's achievement tendency scale for females is examined. The scale predicts better for academic achievement with females classified as non-traditional in sex-role orientation, and in social achievement for females classified as traditional. (Author/JKS)

  18. Measuring Emotions in Students' Learning and Performance: The Achievement Emotions Questionnaire (AEQ)

    Science.gov (United States)

    Pekrun, Reinhard; Goetz, Thomas; Frenzel, Anne C.; Barchfeld, Petra; Perry, Raymond P.

    2011-01-01

    Aside from test anxiety scales, measurement instruments assessing students' achievement emotions are largely lacking. This article reports on the construction, reliability, internal validity, and external validity of the Achievement Emotions Questionnaire (AEQ) which is designed to assess various achievement emotions experienced by students in…

  19. Amplification of Vorticity Near the Stagnation Point of Landing Gear Wheels

    Science.gov (United States)

    Feltham, Graham; Ekmekci, Alis

    2013-11-01

    In this experimental investigation, a stream of steady weak vorticity impinging near the stagnation point of a landing gear wheel is shown to grow and amplify into large-scale vortices that coherently shed from the point of generation. To produce the upstream vorticity, a platinum wire of 100 micron diameter, similar to that used in hydrogen bubble visualization technique, is placed upstream of the wheel model. Experiments are conducted in a recirculating water channel. The wheel diameter is D = 152 mm. The Reynolds number based on the wire diameter is 21 and based on the wheel diameter is 32,500. Qualitative understanding of the vorticity amplification and eventual vortex shedding near the stagnation region of the wheel is achieved by employing the hydrogen bubble visualization technique while quantitative insight is collected using Particle Image Velocimetry (PIV). The size and frequency of the shed vortices are found to depend on the wheel geometry as well as the magnitude and impingement point of the inbound vorticity.

  20. Measuring Metacognition and Reaction Time: Further Findings on the Performances of General Education, Low-Achieving, and Institutionally Raised Students

    Science.gov (United States)

    Al-Hilawani, Yasser A.; Abdullah, Ahmad A.

    2010-01-01

    The purpose of this study was to use the picture format to examine in depth the metacognitive performances and reaction time in general education, low-achieving, and institutionally raised students. Results revealed that institutionally raised students, unlike low-achieving students, took significantly the longest reaction time to finish the test…

  1. A comprehensive approach to decipher biological computation to achieve next generation high-performance exascale computing.

    Energy Technology Data Exchange (ETDEWEB)

    James, Conrad D.; Schiess, Adrian B.; Howell, Jamie; Baca, Micheal J.; Partridge, L. Donald [University of New Mexico, Albuquerque, NM; Finnegan, Patrick Sean; Wolfley, Steven L.; Dagel, Daryl James; Spahn, Olga Blum; Harper, Jason C.; Pohl, Kenneth Roy; Mickel, Patrick R.; Lohn, Andrew; Marinella, Matthew

    2013-10-01

    The human brain (volume=1200cm3) consumes 20W and is capable of performing>10%5E16 operations/s. Current supercomputer technology has reached 1015 operations/s, yet it requires 1500m%5E3 and 3MW, giving the brain a 10%5E12 advantage in operations/s/W/cm%5E3. Thus, to reach exascale computation, two achievements are required: 1) improved understanding of computation in biological tissue, and 2) a paradigm shift towards neuromorphic computing where hardware circuits mimic properties of neural tissue. To address 1), we will interrogate corticostriatal networks in mouse brain tissue slices, specifically with regard to their frequency filtering capabilities as a function of input stimulus. To address 2), we will instantiate biological computing characteristics such as multi-bit storage into hardware devices with future computational and memory applications. Resistive memory devices will be modeled, designed, and fabricated in the MESA facility in consultation with our internal and external collaborators.

  2. A hydrological modeling framework for defining achievable performance standards for pesticides.

    Science.gov (United States)

    Rousseau, Alain N; Lafrance, Pierre; Lavigne, Martin-Pierre; Savary, Stéphane; Konan, Brou; Quilbé, Renaud; Jiapizian, Paul; Amrani, Mohamed

    2012-01-01

    This paper proposes a hydrological modeling framework to define achievable performance standards (APSs) for pesticides that could be attained after implementation of recommended management actions, agricultural practices, and available technologies (i.e., beneficial management practices [BMPs]). An integrated hydrological modeling system, Gestion Intégrée des Bassins versants à l'aide d'un Système Informatisé, was used to quantify APSs for six Canadian watersheds for eight pesticides: atrazine, carbofuran, dicamba, glyphosate, MCPB, MCPA, metolachlor, and 2,4-D. Outputs from simulation runs to predict pesticide concentration under current conditions and in response to implementation of two types of beneficial management practices (reduced pesticide application rate and 1- to 10-m-wide edge-of-field and/or riparian buffer strips, implemented singly or in combination) showed that APS values for scenarios with BMPs were less than those for current conditions. Moreover, APS values at the outlet of watersheds were usually less than ecological thresholds of good condition, when available. Upstream river reaches were at greater risk of having concentrations above a given ecological thresholds because of limited stream flows and overland loads of pesticides. Our integrated approach of "hydrological modeling-APS estimation-ecotoxicological significance" provides the most effective interpretation possible, for management and education purposes, of the potential biological impact of predicted pesticide concentrations in rivers.

  3. Performance of Learning Disabled and Low Achieving Secondary Students on Formal Features of a Paragraph-Writing Task.

    Science.gov (United States)

    Moran, Mary Ross

    1981-01-01

    Writing samples were analyzed for syntactic maturity, productivity and word selection; for conventions such as tense and number markers and number agreement; and for spelling, punctuation, and capitalization. Only spelling performance proved significantly different in favor of low achievers. (Author)

  4. Physical Activity Before School, Cognitive Performance, and Academic Achievement in Dutch Adolescents: Let them Walk or Cycle to School!

    NARCIS (Netherlands)

    Van Dijk, Martin; De Groot, Renate; Van Acker, Frederik; Savelberg, Hans; Kirschner, Paul A.

    2014-01-01

    In this study, associations between objectively measured active commuting to school and cognitive performance and academic achievement in Dutch adolescents were investigated. Active commuting to school was found to be positively associated with executive functioning in adolescent girls.

  5. The CryoSat Interferometer after 6 years in orbit: calibration and achievable performance

    Science.gov (United States)

    Scagliola, Michele; Fornari, Marco; De Bartolomei, Maurizio; Bouffard, Jerome; Parrinello, Tommaso

    2016-04-01

    The main payload of CryoSat is a Ku-band pulse width limited radar altimeter, called SIRAL (Synthetic interferometric radar altimeter). When commanded in SARIn (synthetic aperture radar interferometry) mode, through coherent along-track processing of the returns received from two antennas, the interferometric phase related to the first arrival of the echo is used to retrieve the angle of arrival of the scattering in the across-track direction. In fact, the across-track echo direction can be derived by exploiting the precise knowledge of the baseline vector (i.e. the vector between the two antennas centers of phase) and simple geometry. The end-to-end calibration strategy for the CryoSat interferometer consists on in-orbit calibration campaigns following the approach described in [1]. From the beginning of the CryoSat mission, about once a year the interferometer calibration campaigns have been periodically performed by rolling left and right the spacecraft of about ±0.4 deg. This abstract is aimed at presenting our analysis of the calibration parameters and of the achievable performance of the CryoSat interferometer over the 6 years of mission. Additionally, some further studies have been performed to assess the accuracy of the roll angle computed on ground as function of the aberration (the apparent displacement of a celestial object from its true position, caused by the relative motion of the observer and the object) correction applied to the attitude quaternions, provided by the Star Tracker mounted on-board. In fact, being the roll information crucial to obtain an accurate estimate of the angle of arrival, the data from interferometer calibration campaigns have been used to verify how the application of the aberration correction affects the roll information and, in turns, the measured angle of arrival. [1] Galin, N.; Wingham, D.J.; Cullen, R.; Fornari, M.; Smith, W.H.F.; Abdalla, S., "Calibration of the CryoSat-2 Interferometer and Measurement of Across

  6. Tracking Student Achievement in Music Performance: Developing Student Learning Objectives for Growth Model Assessments

    Science.gov (United States)

    Wesolowski, Brian C.

    2015-01-01

    Student achievement growth data are increasingly used for assessing teacher effectiveness and tracking student achievement in the classroom. Guided by the student learning objective (SLO) framework, music teachers are now responsible for collecting, tracking, and reporting student growth data. Often, the reported data do not accurately reflect the…

  7. Cohort versus Non-Cohort High School Students' Math Performance: Achievement Test Scores and Coursework

    Science.gov (United States)

    Parke, Carol S.; Keener, Dana

    2011-01-01

    The purpose of this study is to compare multiple measures of mathematics achievement for 1,378 cohort students who attended the same high school in a district from 9th to 12th grade with non-cohort students in each grade level. Results show that mobility had an impact on math achievement. After accounting for gender, ethnicity, and SES, adjusted…

  8. Performance-Based Music Ensembles' Effects on Academic Achievement: A Correlational Study

    Science.gov (United States)

    Stevenson, Timothy Francis

    2013-01-01

    As increasing student achievement levels for all learners continues to drive the focus of education, identifying strategies and opportunities to accomplish this goal becomes progressively more important. This study explored the concepts of self-efficacy, self-efficacy for self-regulated learning, and self-efficacy for academic achievement in…

  9. Relationships of cognitive and metacognitive learning strategies to mathematics achievement in four high-performing East Asian education systems.

    Science.gov (United States)

    Areepattamannil, Shaljan; Caleon, Imelda S

    2013-01-01

    The authors examined the relationships of cognitive (i.e., memorization and elaboration) and metacognitive learning strategies (i.e., control strategies) to mathematics achievement among 15-year-old students in 4 high-performing East Asian education systems: Shanghai-China, Hong Kong-China, Korea, and Singapore. In all 4 East Asian education systems, memorization strategies were negatively associated with mathematics achievement, whereas control strategies were positively associated with mathematics achievement. However, the association between elaboration strategies and mathematics achievement was a mixed bag. In Shanghai-China and Korea, elaboration strategies were not associated with mathematics achievement. In Hong Kong-China and Singapore, on the other hand, elaboration strategies were negatively associated with mathematics achievement. Implications of these findings are briefly discussed.

  10. Climatic and technological ceilings for Chinese rice stagnation based on yield gaps and yield trend pattern analysis.

    Science.gov (United States)

    Zhang, Tianyi; Yang, Xiaoguang; Wang, Hesong; Li, Yong; Ye, Qing

    2014-04-01

    Climatic or technological ceilings could cause yield stagnation. Thus, identifying the principal reasons for yield stagnation within the context of the local climate and socio-economic conditions are essential for informing regional agricultural policies. In this study, we identified the climatic and technological ceilings for seven rice-production regions in China based on yield gaps and on a yield trend pattern analysis for the period 1980-2010. The results indicate that 54.9% of the counties sampled experienced yield stagnation since the 1980. The potential yield ceilings in northern and eastern China decreased to a greater extent than in other regions due to the accompanying climate effects of increases in temperature and decreases in radiation. This may be associated with yield stagnation and halt occurring in approximately 49.8-57.0% of the sampled counties in these areas. South-western China exhibited a promising scope for yield improvement, showing the greatest yield gap (30.6%), whereas the yields were stagnant in 58.4% of the sampled counties. This finding suggests that efforts to overcome the technological ceiling must be given priority so that the available exploitable yield gap can be achieved. North-eastern China, however, represents a noteworthy exception. In the north-central area of this region, climate change has increased the yield potential ceiling, and this increase has been accompanied by the most rapid increase in actual yield: 1.02 ton ha(-1) per decade. Therefore, north-eastern China shows a great potential for rice production, which is favoured by the current climate conditions and available technology level. Additional environmentally friendly economic incentives might be considered in this region. PMID:24130084

  11. Stagnation region gas film cooling: Spanwise angled injection from multiple rows of holes. [gas turbine engines

    Science.gov (United States)

    Luckey, D. W.; Lecuyer, M. R.

    1981-01-01

    The stagnation region of a cylinder in a cross flow was used in experiments conducted with both a single row and multiple rows of spanwise angled (25 deg) coolant holes for a range of the coolant blowing ratio with a freestream to wall temperature ratio approximately equal to 1.7 and R(eD) = 90,000. Data from local heat flux measurements are presented for injection from a single row located at 5 deg, 22.9 deg, 40.8 deg, 58.7 deg from stagnation using a hole spacing ratio of S/d(o) = 5 and 10. Three multiple row configurations were also investigated. Data are presented for a uniform blowing distribution and for a nonuniform blowing distribution simulating a plenum supply. The data for local Stanton Number reduction demonstrated a lack of lateral spreading by the coolant jets. Heat flux levels larger than those without film cooling were observed directly behind the coolant holes as the blowing ratio exceeded a particular value. The data were spanwise averaged to illustrate the influence of injection location, blowing ratio and hole spacing. The large values of blowing ratio for the blowing distribution simulating a plenum supply resulted in heat flux levels behind the holes in excess of the values without film cooling. An increase in freestream turbulence intensity from 4.4 to 9.5 percent had a negligible effect on the film cooling performance.

  12. Stagnation of electron flow by a nonlinearly generated whistler wave

    CERN Document Server

    Taguchi, Toshihiro; Mima, Kunioki

    2016-01-01

    Relativistic electron beam transport through a high-density, magnetized plasma is studied numerically and theoretically. An electron beam injected into a cold plasma excites Weibel and two-stream instabilities that heat the beam and saturate. In the absence of an applied magnetic field, the heated beam continues to propagate. However, when a magnetic field of particular strength is applied along the direction of beam propagation, a secondary instability of off-angle whistler modes is excited. These modes then couple nonlinearly creating a large amplitude parallel propagating whistler that stops the beam. In this letter, we will show the phenomena in detail and explain the mechanism of whistler mediated beam stagnation.

  13. Stagnation and interpenetration of laser-created colliding plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Pollaine, S.M.; Albritton, J.R.; Kauffman, R.; Keane, C.J. (Lawrence Livermore National Lab., CA (USA)); Berger, R.L.; Bosch, R.; Delameter, N.D.; Failor, B.H. (KMS Fusion, Inc., Ann Arbor, MI (USA))

    1990-11-05

    A KMS laser experiment collides Aluminum (A1) and Magnesium (Mg) plasmas. The measurements include electron density, time and space resolved Ly-alpha and He-alpha lines of Al and Mg, and x-ray images. These measurements were analyzed with a hydrodynamic code, LASNEX, and a special two-fluid code OFIS. The results strongly suggest that at early times, the Al interpenetrates the counterstreaming Mg and deposits in the dense Mg region. At late times, the Al plasma stagnates against the Mg plasma.

  14. Avoiding Intellectual Stagnation: The Starship as an Expander of Minds

    CERN Document Server

    Crawford, Ian A

    2015-01-01

    Interstellar exploration will advance human knowledge and culture in multiple ways. Scientifically, it will advance our understanding of the interstellar medium, stellar astrophysics, planetary science and astrobiology. In addition, significant societal and cultural benefits will result from a programme of interstellar exploration and colonisation. Most important will be the cultural stimuli resulting from expanding the horizons of human experience, and increased opportunities for the spread and diversification of life and culture through the Galaxy. Ultimately, a programme of interstellar exploration may be the only way for human (and post-human) societies to avoid the intellectual stagnation predicted for the "end of history".

  15. Stagnation Region Heat Transfer Augmentation at Very High Turbulence Levels

    Energy Technology Data Exchange (ETDEWEB)

    Ames, Forrest [University of North Dakota; Kingery, Joseph E. [University of North Dakota

    2015-06-17

    A database for stagnation region heat transfer has been extended to include heat transfer measurements acquired downstream from a new high intensity turbulence generator. This work was motivated by gas turbine industry heat transfer designers who deal with heat transfer environments with increasing Reynolds numbers and very high turbulence levels. The new mock aero-combustor turbulence generator produces turbulence levels which average 17.4%, which is 37% higher than the older turbulence generator. The increased level of turbulence is caused by the reduced contraction ratio from the liner to the exit. Heat transfer measurements were acquired on two large cylindrical leading edge test surfaces having a four to one range in leading edge diameter (40.64 cm and 10.16 cm). Gandvarapu and Ames [1] previously acquired heat transfer measurements for six turbulence conditions including three grid conditions, two lower turbulence aero-combustor conditions, and a low turbulence condition. The data are documented and tabulated for an eight to one range in Reynolds numbers for each test surface with Reynolds numbers ranging from 62,500 to 500,000 for the large leading edge and 15,625 to 125,000 for the smaller leading edge. The data show augmentation levels of up to 136% in the stagnation region for the large leading edge. This heat transfer rate is an increase over the previous aero-combustor turbulence generator which had augmentation levels up to 110%. Note, the rate of increase in heat transfer augmentation decreases for the large cylindrical leading edge inferring only a limited level of turbulence intensification in the stagnation region. The smaller cylindrical leading edge shows more consistency with earlier stagnation region heat transfer results correlated on the TRL (Turbulence, Reynolds number, Length scale) parameter. The downstream regions of both test surfaces continue to accelerate the flow but at a much lower rate than the leading edge. Bypass transition occurs

  16. Injection-induced turbulence in stagnation-point boundary layers

    Science.gov (United States)

    Park, C.

    1984-02-01

    A theory is developed for the stagnation point boundary layer with injection under the hypothesis that turbulence is produced at the wall by injection. From the existing experimental heat transfer rate data obtained in wind tunnels, the wall mixing length is deduced to be a product of a time constant and an injection velocity. The theory reproduces the observed increase in heat transfer rates at high injection rates. For graphite and carbon-carbon composite, the time constant is determined to be 0.0002 sec from the existing ablation data taken in an arc-jet tunnel and a balistic range.

  17. Achievable Performance and Effective Interrogator Design for SAW RFID Sensor Tags

    Science.gov (United States)

    Barton Richard J.

    2012-01-01

    current generation tags limits the performance in a cluttered sensing environment. That is, as more SAW-based sensors are added to the environment, numerous tag responses are superimposed at the receiver and decoding all or even a subset of the telemetry becomes increasingly difficult. Background clutter generated by reflectors other than the sensors themselves is also a problem, as is multipath interference and signal distortion, but the limiting factor in many remote sensing applications can be expected to be tag mutual interference. This problem may be greatly mitigated by proper design of the SAW tag waveform, but that remains an open research problem, and in the meantime, several other related questions remain to be answered including: (1) What are the fundamental relationships between tag parameters such as bit-rate, time-bandwidth-product, SNR, and achievable collision resolution? (2) What are the differences in optimal or near-optimal interrogator designs between noise-limited environments and interference-limited environments? (3) What are the performance characteristics of different interrogator designs in term of parameters such as transmitter power level, range, and number of interfering tags? In this paper, we will present the results of a research effort aimed at providing at least partial answers to all of these questions.

  18. Standard Test Method for Calculation of Stagnation Enthalpy from Heat Transfer Theory and Experimental Measurements of Stagnation-Point Heat Transfer and Pressure

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers the calculation from heat transfer theory of the stagnation enthalpy from experimental measurements of the stagnation-point heat transfer and stagnation pressure. 1.2 Advantages 1.2.1 A value of stagnation enthalpy can be obtained at the location in the stream where the model is tested. This value gives a consistent set of data, along with heat transfer and stagnation pressure, for ablation computations. 1.2.2 This computation of stagnation enthalpy does not require the measurement of any arc heater parameters. 1.3 Limitations and ConsiderationsThere are many factors that may contribute to an error using this type of approach to calculate stagnation enthalpy, including: 1.3.1 TurbulenceThe turbulence generated by adding energy to the stream may cause deviation from the laminar equilibrium heat transfer theory. 1.3.2 Equilibrium, Nonequilibrium, or Frozen State of GasThe reaction rates and expansions may be such that the gas is far from thermodynamic equilibrium. 1.3.3 Noncat...

  19. Credit Markets and Stagnation in an Endogenous Growth Model Credit Markets and Stagnation in an Endogenous Growth Model

    Directory of Open Access Journals (Sweden)

    José De Gregorio

    1993-03-01

    Full Text Available Credit Markets and Stagnation in an Endogenous Growth Model This paper studies the effects that the inability of individuals to borrow against future income has on economic growth. The model assumes that human capitals, which is accumulated through education, is the onlv factor of production. It is shown that liquidity contraints reduce growth. Further, in the presence of externalities that may induce two equilibria, it is shown that liquidity constraints not only reduce the rate of growth in the highgrowth equilibrium, but can also make the low-growth equilibrium more likely to occur.

  20. The effect of social trust on achievement test performance of students in Japan

    OpenAIRE

    YAMAMURA, Eiji

    2010-01-01

    Empirical results using Japanese data suggest that social trust improves student language and mathematics achievement test scores in primary and junior high school. After controlling for endogeneity bias, social trust had a greater effect on scores for primary school students than on scores for junior high school students.

  1. Do Children in Montessori Schools Perform Better in the Achievement Test? A Taiwanese Perspective

    Science.gov (United States)

    Peng, Hsin-Hui; Md-Yunus, Sham'ah

    2014-01-01

    The study examines whether elementary school students in Taiwan who had received Montessori education achieved significantly higher scores on tests of language arts, math, and social studies than students who attended non-Montessori elementary programs. One hundred ninety six children in first, second, and third grade participated in the study.…

  2. Performance Evaluation of Methods for Estimating Achievable Throughput on Cellular Connections

    DEFF Research Database (Denmark)

    Mikkelsen, Lars Møller; Højholt, Nikolaj Bove; Madsen, Tatiana Kozlova

    2015-01-01

    achievable throughput (AT) is the main focus of this paper, which can be expressed as the data rate that users experience. We establish the Bulk Transfer Capacity (BTC) method as the ground truth of the AT. We choose to evaluate the Trains of Packet-Pair (TOPP) method as an alternative to BTC in estimating...

  3. Immigrant Children's Educational Achievement in Western Countries : Origin, Destination, and Community Effects on Mathematical Performance

    NARCIS (Netherlands)

    Levels, Mark; Dronkers, Jaap; Kraaykamp, Gerbert

    2008-01-01

    ICS Radboud University Nijmegen This article explores the extent to which macro-level characteristics of destination countries, origin countries, and immigrant communities help explain differences in immigrant children’s educational achievement. Using data from the 2003 PISA survey, we analyze the m

  4. Nursing to achieve organizational performance: Consider the role of nursing intellectual capital.

    Science.gov (United States)

    Harris, Alexandra

    2016-05-01

    The success and performance of healthcare organizations relies on the strategic management of knowledge. Nursing Intellectual Capital (NIC) has emerged as a concept involving nursing knowledge resources that create value in healthcare organizations. This article aims to discuss the importance of considering knowledge resources in the context of healthcare performance, with specific reference to NIC. Reflections are then provided on how leaders can look to advance NIC for improved performance. PMID:27060807

  5. Energy thrift and improved performance achieved through novel railway brake discs

    International Nuclear Information System (INIS)

    A disc with radial vanes and circumferential pillars proves to be successful in operation and achieves energy efficiency improvements compared with those of traditional design. Cooling characteristics of this novel design are practically identical to the disc with tangential vanes but the equivalent aerodynamic (air pumping) losses are approximately 50% less. It is shown that these reductions in pumping losses can lead to substantial energy savings in train operations. When developing new designs and/or comparing different railway disc designs, the proposed disc cooling to aerodynamic efficiency ratio (ηv) was found to be a very useful parameter to assess. This 'efficiency ratio' - a ratio of convective power dissipation to aerodynamic power losses can help in achieving adequate balance of cooling efficiency and aerodynamic losses to suit particular application. The use of CFD is of enormous benefit in generating discs that fulfil these demanding requirements, with the spin rig being exceptionally useful for experimental work

  6. The Augmented Performer and the Performative Augmentation

    DEFF Research Database (Denmark)

    Kallionpaa, Maria; Gasselseder, Hans-Peter

    2016-01-01

    Composers, performers, and listeners usually regard musical compositions as unchangeable entities, which limits the composition techniques and decreases the originality of performers ́ interpretations, thus leading to a stagnation of classical music culture. The significance and possibilities of ...

  7. Predicting arithmetical achievement from neuro-psychological performance: a longitudinal study.

    Science.gov (United States)

    Fayol, M; Barrouillet, P; Marinthe, C

    1998-08-01

    In this article, we show that the performances of 5- to 6-year-old children in arithmetic tests can be predicted from their performances in neuro-psychological tests administered a number of months in advance, independently of their level of development. PMID:9818514

  8. The Effect of Performance Pay in Little Rock, Arkansas on Student Achievement. Research Brief

    Science.gov (United States)

    Winters, Marcus; Greene, Jay; Ritter, Gary; Marsh, Ryan

    2008-01-01

    This paper examines evidence from a performance-pay program implemented in five Little Rock, Arkansas elementary schools between 2004 and 2007. Using a differences-in-differences approach, the evidence shows that students whose teachers were eligible for performance pay made substantially larger test score gains in math, reading, and language than…

  9. A University Engagement Model for Achieving Technology Adoption and Performance Improvement Impacts in Healthcare, Manufacturing, and Government

    Science.gov (United States)

    McKinnis, David R.; Sloan, Mary Anne; Snow, L. David; Garimella, Suresh V.

    2014-01-01

    The Purdue Technical Assistance Program (TAP) offers a model of university engagement and service that is achieving technology adoption and performance improvement impacts in healthcare, manufacturing, government, and other sectors. The TAP model focuses on understanding and meeting the changing and challenging needs of those served, always…

  10. The Relationship between Students' Reading Performance on Diagnostic Assessments and the Third Grade Reading Achievement Test in Ohio

    Science.gov (United States)

    Hollinger, Jamie L.

    2009-01-01

    The purpose of this correlational study was twofold: to examine the relationship of students' reading performance on six different diagnostic reading assessments and the third grade Ohio Reading Achievement Test; and to assist educators in choosing the diagnostic assessments that best identify students at risk of failing the third grade Ohio…

  11. Active commuting to school, cognitive performance, and academic achievement: an observational study in Dutch adolescents using accelerometers

    NARCIS (Netherlands)

    Van Dijk, Martin; De Groot, Renate; Van Acker, Frederik; Savelberg, Hans; Kirschner, Paul A.

    2014-01-01

    Background: The current study examined the associations between active commuting to school, cognitive performance, and academic achievement in Dutch adolescents. In addition, it was explored whether these associations were moderated by sex and mediated by depressive symptoms. Methods: Students in gr

  12. Relationships of Cognitive and Metacognitive Learning Strategies to Mathematics Achievement in Four High-Performing East Asian Education Systems

    Science.gov (United States)

    Areepattamannil, Shaljan; Caleon, Imelda S.

    2013-01-01

    The authors examined the relationships of cognitive (i.e., memorization and elaboration) and metacognitive learning strategies (i.e., control strategies) to mathematics achievement among 15-year-old students in 4 high-performing East Asian education systems: Shanghai-China, Hong Kong-China, Korea, and Singapore. In all 4 East Asian education…

  13. Conscientiousness, Achievement Striving, and Intelligence as Performance Predictors in a Sample of German Psychology Students: Always a Linear Relationship?

    Science.gov (United States)

    Ziegler, Matthias; Knogler, Maximilian; Buhner, Markus

    2009-01-01

    Studies on the interface between cognitive ability (intelligence) and personality in the prediction of academic performance have yielded mixed results so far. Especially an interaction between conscientiousness (and its facet achievement striving) and intelligence has been investigated. The hypothesis is that conscientiousness enhances the impact…

  14. The Relationship of Selected Measures of Proprioception to Physical Growth, Motor Performance, and Academic Achievement in Young Children.

    Science.gov (United States)

    Haubenstricker, John L.; Milne, D. Conrad

    This study investigates the relationship of selected measures of proprioception to measures of physical growth, motor performance, and academic achievement in young children. Measures were obtained from 321 boys and girls attending kindergarten and first and second grade. Sample correlation matrices were computed on all variables at each grade…

  15. Locus of Control and Achievement Motivation as Moderators of the Expectancy-Academic Performance Relationship

    Science.gov (United States)

    Batlis, Nick C.; Waters, L. K.

    1973-01-01

    Expectancy theory predictions of course performance were tested for a sample of 195 undergraduates; significant prediction was attained for the total sample using a log linear expectancy model. (Author)

  16. Two-Dimensional Finite Element Ablative Thermal Response Analysis of an Arcjet Stagnation Test

    Science.gov (United States)

    Dec, John A.; Laub, Bernard; Braun, Robert D.

    2011-01-01

    The finite element ablation and thermal response (FEAtR, hence forth called FEAR) design and analysis program simulates the one, two, or three-dimensional ablation, internal heat conduction, thermal decomposition, and pyrolysis gas flow of thermal protection system materials. As part of a code validation study, two-dimensional axisymmetric results from FEAR are compared to thermal response data obtained from an arc-jet stagnation test in this paper. The results from FEAR are also compared to the two-dimensional axisymmetric computations from the two-dimensional implicit thermal response and ablation program under the same arcjet conditions. The ablating material being used in this arcjet test is phenolic impregnated carbon ablator with an LI-2200 insulator as backup material. The test is performed at the NASA, Ames Research Center Interaction Heating Facility. Spatially distributed computational fluid dynamics solutions for the flow field around the test article are used for the surface boundary conditions.

  17. Nonlinear radiative heat transfer to stagnation-point flow of Sisko fluid past a stretching cylinder

    Science.gov (United States)

    Khan, Masood; Malik, Rabia; Hussain, M.

    2016-05-01

    In the present paper, we endeavor to perform a numerical analysis in connection with the nonlinear radiative stagnation-point flow and heat transfer to Sisko fluid past a stretching cylinder in the presence of convective boundary conditions. The influence of thermal radiation using nonlinear Rosseland approximation is explored. The numerical solutions of transformed governing equations are calculated through forth order Runge-Kutta method using shooting technique. With the help of graphs and tables, the influence of non-dimensional parameters on velocity and temperature along with the local skin friction and Nusselt number is discussed. The results reveal that the temperature increases however, heat transfer from the surface of cylinder decreases with the increasing values of thermal radiation and temperature ratio parameters. Moreover, the authenticity of numerical solutions is validated by finding their good agreement with the HAM solutions.

  18. Thermoelastic Analysis of Hyper-X Camera Windows Suddenly Exposed to Mach 7 Stagnation Aerothermal Shock

    Science.gov (United States)

    Ko, William L.; Gong, Leslie

    2000-01-01

    To visually record the initial free flight event of the Hyper-X research flight vehicle immediately after separation from the Pegasus(registered) booster rocket, a video camera was mounted on the bulkhead of the adapter through which Hyper-X rides on Pegasus. The video camera was shielded by a protecting camera window made of heat-resistant quartz material. When Hyper-X separates from Pegasus, this camera window will be suddenly exposed to Mach 7 stagnation thermal shock and dynamic pressure loading (aerothermal loading). To examine the structural integrity, thermoelastic analysis was performed, and the stress distributions in the camera windows were calculated. The critical stress point where the tensile stress reaches a maximum value for each camera window was identified, and the maximum tensile stress level at that critical point was found to be considerably lower than the tensile failure stress of the camera window material.

  19. The magnetohydrodynamic stagnation point flow of a nanofluid over a stretching/shrinking sheet with suction.

    Science.gov (United States)

    Mansur, Syahira; Ishak, Anuar; Pop, Ioan

    2015-01-01

    The magnetohydrodynamic (MHD) stagnation point flow of a nanofluid over a permeable stretching/shrinking sheet is studied. Numerical results are obtained using boundary value problem solver bvp4c in MATLAB for several values of parameters. The numerical results show that dual solutions exist for the shrinking case, while for the stretching case, the solution is unique. A stability analysis is performed to determine the stability of the dual solutions. For the stable solution, the skin friction is higher in the presence of magnetic field and increases when the suction effect is increased. It is also found that increasing the Brownian motion parameter and the thermophoresis parameter reduces the heat transfer rate at the surface.

  20. The Magnetohydrodynamic Stagnation Point Flow of a Nanofluid over a Stretching/Shrinking Sheet with Suction

    Science.gov (United States)

    Mansur, Syahira; Ishak, Anuar; Pop, Ioan

    2015-01-01

    The magnetohydrodynamic (MHD) stagnation point flow of a nanofluid over a permeable stretching/shrinking sheet is studied. Numerical results are obtained using boundary value problem solver bvp4c in MATLAB for several values of parameters. The numerical results show that dual solutions exist for the shrinking case, while for the stretching case, the solution is unique. A stability analysis is performed to determine the stability of the dual solutions. For the stable solution, the skin friction is higher in the presence of magnetic field and increases when the suction effect is increased. It is also found that increasing the Brownian motion parameter and the thermophoresis parameter reduces the heat transfer rate at the surface. PMID:25760733

  1. The magnetohydrodynamic stagnation point flow of a nanofluid over a stretching/shrinking sheet with suction.

    Directory of Open Access Journals (Sweden)

    Syahira Mansur

    Full Text Available The magnetohydrodynamic (MHD stagnation point flow of a nanofluid over a permeable stretching/shrinking sheet is studied. Numerical results are obtained using boundary value problem solver bvp4c in MATLAB for several values of parameters. The numerical results show that dual solutions exist for the shrinking case, while for the stretching case, the solution is unique. A stability analysis is performed to determine the stability of the dual solutions. For the stable solution, the skin friction is higher in the presence of magnetic field and increases when the suction effect is increased. It is also found that increasing the Brownian motion parameter and the thermophoresis parameter reduces the heat transfer rate at the surface.

  2. Rise, stagnation, and rise of Danish women's life expectancy

    DEFF Research Database (Denmark)

    Lindahl-Jacobsen, Rune; Rau, Roland; Jeune, Bernard;

    2016-01-01

    or later. Because it is difficult to disentangle period effects from cohort effects, demographers, epidemiologists, actuaries, and other population scientists often disagree about cohort effects' relative importance. In particular, some advocate forecasts of life expectancy based on period trends; others...... favor forecasts that hinge on cohort differences. We use a combination of age decomposition and exchange of survival probabilities between countries to study the remarkable recent history of female life expectancy in Denmark, a saga of rising, stagnating, and now again rising lifespans. The gap between...... female life expectancy in Denmark vs. Sweden grew to 3.5 y in the period 1975-2000. When we assumed that Danish women born 1915-1945 had the same survival probabilities as Swedish women, the gap remained small and roughly constant. Hence, the lower Danish life expectancy is caused by these cohorts...

  3. Mass flow rate measurements in two-phase mixtrues with stagnation probes. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Fincke, J.R.; Deason, V.A.

    1979-01-01

    Applications of stagnation probes to the measurement of mass flow rate in two-phase flows are discussed. Descriptions of several stagnation devices, which have been evaluated at the Idaho National Engineering Laboratory, are presented along with modeling techniques and two-phase flow data.

  4. Achievable ADC Performance by Postcorrection Utilizing Dynamic Modeling of the Integral Nonlinearity

    Directory of Open Access Journals (Sweden)

    Peter Händel

    2008-03-01

    Full Text Available There is a need for a universal dynamic model of analog-to-digital converters (ADC’s aimed for postcorrection. However, it is complicated to fully describe the properties of an ADC by a single model. An alternative is to split up the ADC model in different components, where each component has unique properties. In this paper, a model based on three components is used, and a performance analysis for each component is presented. Each component can be postcorrected individually and by the method that best suits the application. The purpose of postcorrection of an ADC is to improve the performance. Hence, for each component, expressions for the potential improvement have been developed. The measures of performance are total harmonic distortion (THD and signal to noise and distortion (SINAD, and to some extent spurious-free dynamic range (SFDR.

  5. Coping with stress and cognitive interference in student teachers performance as important factors influencing their achievement

    Directory of Open Access Journals (Sweden)

    Cirila Peklaj

    2001-06-01

    Full Text Available The purpose of our study was to investigate the relations between student teachers' strategies for coping with stressful situations, cognitive interference factors and successfulness of presentation of student teachers' seminar work. There were 135 student teachers participating in the study. At the beginning of the semester they filled in the Way of Coping Questionnaire (Folkman & Lazarus, 1988. After their presentation of seminar theme they reported about the cognitive interference factors during the presentation (distractive factors and intrusive thoughts. Different aspects of their performance were also evaluated by the teacher according to the well-known criteria. The analysis of the results showed significant correlations between certain ways of coping, cognitive interference factors and success of performance. Further statistical analysis showed significant differences in experiencing distractive factors and intrusive thoughts during presentation between students with low, medium and high performance success. The importance of successful strategies for coping with verbal presentation and the implications for student teacher education are discussed.

  6. NEMO5: Achieving High-end Internode Communication for Performance Projection Beyond Moore's Law

    CERN Document Server

    Andrawis, Robert; Charles, James; Fang, Jianbin; Fonseca, Jim; He, Yu; Klimeck, Gerhard; Jiang, Zhengping; Kubis, Tillmann; Mejia, Daniel; Lemus, Daniel; Povolotskyi, Michael; Rubiano, Santiago Alonso Perez; Sarangapani, Prasad; Zeng, Lang

    2015-01-01

    Electronic performance predictions of modern nanotransistors require nonequilibrium Green's functions including incoherent scattering on phonons as well as inclusion of random alloy disorder and surface roughness effects. The solution of all these effects is numerically extremely expensive and has to be done on the world's largest supercomputers due to the large memory requirement and the high performance demands on the communication network between the compute nodes. In this work, it is shown that NEMO5 covers all required physical effects and their combination. Furthermore, it is also shown that NEMO5's implementation of the algorithm scales very well up to about 178176CPUs with a sustained performance of about 857 TFLOPS. Therefore, NEMO5 is ready to simulate future nanotransistors.

  7. Modified surface loading process for achieving improved performance of the quantum dot-sensitized solar cells

    Science.gov (United States)

    Liu, Feng; Jin, Zhongxiu; Zhu, Jun; Xu, Yafeng; Zhou, Li; Dai, Songyuan

    2016-06-01

    Achieving high surface coverage of the colloidal quantum dots (QDs) on TiO2 films has been challenging for quantum dot-sensitized solar cells (QDSCs). Herein, a general surface engineering approach was proposed to increase the loading of these QDs. It was found that S2- treatment/QD re-uptake process can significantly improve the attachment of the QDs on TiO2 films. Surface concentration of the QDs was improved by ∼60%, which in turn greatly enhances light absorption and decreases carrier recombination in QDSCs. Ensuing QDSCs with optimized QD loading exhibit a power conversion efficiency of 3.66%, 83% higher than those fabricated with standard procedures.

  8. Use of neurofeedback to achieve human performance enhancement in the nuclear power industry

    Energy Technology Data Exchange (ETDEWEB)

    Freer, P. [Freer Logic (United States); Chandler, K. [Univ. of Windsor, Dept. of Kinesiology, Windsor, Ontario (Canada); Lane, L.; Templeton, R. [Ontario Power Generation, Toronto, Ontario (Canada)

    2007-07-01

    The nuclear industry has spent many millions of dollars to provide training to personnel to operate our nuclear facilities. However, even with excellent training programs, candidates often fail examinations. For many, the debilitating effects of performance anxiety are contributing factors. Neurofeedback technology instantly presents psychophysiological feedback to the trainee while the trainee is performing a training task. This feedback can teach the trainee to effectively cope with environmental and psychological stressors. We hypothesize that NF training can help NPPs resolve staffing and training challenges while yielding a high ROI by ultimately improving success rates for Certification training candidates. (author)

  9. Seasonal Reversals of Groundwater Flow Around Lakes and the Relevance to Stagnation Points and Lake Budgets

    Science.gov (United States)

    Anderson, Mary P.; Munter, James A.

    1981-08-01

    Several researchers have observed seasonal reversals in the direction of groundwater flow around lakes. If these reversals are prolonged and are accompanied by the formation of a stagnation point, they may have a significant effect on a lake's water and nutrient budgets. The formation of a stagnation point at a flow-through lake (i.e., a lake that receives groundwater through part of the lake basin and recharges the groundwater system over the rest of the lake basin) is accomplished by the formation of a groundwater mound on the downgradient side of the lake. In this paper the seasonal formation of a stagnation point at Snake Lake, Wisconsin, is investigated with the aid of two-dimensional transient computer models applied in cross section and areally. The analysis demonstrates the potential for the seasonal formation of a stagnation point at a flow-through lake and provides some insight into the transient development of the stagnation point.

  10. The role of supply chain action programs in achieving operational performance excellence

    DEFF Research Database (Denmark)

    Farooq, Sami; Dukovska-Popovska, Iskra; Boer, Harry

    2009-01-01

    This paper investigates the effects of five individual supply chain action programs on cost and speed aspects of procurement and manufacturing performance. The study is based on the IMSS-IV database. As should be expected, supply chain action programs have stronger effects on externally oriented...

  11. Teacher Performance Pay Signals and Student Achievement: Are Signals Accurate, and How well Do They Work?

    Science.gov (United States)

    Manzeske, David; Garland, Marshall; Williams, Ryan; West, Benjamin; Kistner, Alexandra Manzella; Rapaport, Amie

    2016-01-01

    High-performing teachers tend to seek out positions at more affluent or academically challenging schools, which tend to hire more experienced, effective educators. Consequently, low-income and minority students are more likely to attend schools with less experienced and less effective educators (see, for example, DeMonte & Hanna, 2014; Office…

  12. Initial Teacher Education: Does Self-Efficacy Influence Candidate Teacher Academic Achievement and Future Career Performance?

    Science.gov (United States)

    Shawer, Saad F.

    2013-01-01

    This quantitative investigation examined the influence of low and high self-efficacy on candidate teacher academic performance in a foreign language teaching methodology course through testing the speculation that high self-efficacy levels would improve pedagogical-content knowledge (PCK). Positivism guided the research design at the levels of…

  13. "High" Achievers? Cannabis Access and Student Performance. CEP Discussion Paper No. 1340

    Science.gov (United States)

    Marie, Olivier; Zölitz, Ulf

    2015-01-01

    This paper investigates how legal cannabis access affects student performance. Identification comes from an exceptional policy introduced in the city of Maastricht which discriminated legal access based on individuals' nationality. We apply a difference-in-difference approach using administrative panel data on over 54,000 course grades of local…

  14. Paying Teachers According to Student Achievement: Questions regarding Pay-for-Performance Models in Public Education

    Science.gov (United States)

    Caillier, James

    2010-01-01

    In an effort to correct for perceived deficiencies in the No Child Left Behind Act, value-added models were proposed as a way to find out how much students learned in schools and classrooms throughout the school year. What has garnered much controversy regarding the value-added model, however, is the attempt to link pay and tenure to performance.…

  15. Use of performance curves in estimating number of procedures required to achieve proficiency in coronary angiography

    DEFF Research Database (Denmark)

    Räder, Sune B E W; Jørgensen, Erik; Bech, Bo;

    2011-01-01

    Background: Current guidelines in cardiology training programs recommend 100-300 coronary angiography procedures for certification. We aimed to assess the number of procedures needed to reach sufficient proficiency. Methods: Procedure time, fluoroscopy time, dose area product (DAP), and contrast...... needed for trainees to reach recommended reference levels was estimated as 226 and 353, for DAP and use of contrast media, respectively. After 300 procedures, trainees' procedure time, fluoroscopy time, DAP, and contrast media volume were significantly higher compared with experts' performance, P ....001 for all parameters. To approach the experts' level of DAP and contrast media use, trainees need 394 and 588 procedures, respectively. Performance curves showed large individual differences in the development of competence. Conclusion: On average, trainees needed 300 procedures to reach sufficient level...

  16. How to Achieve the Best SRF Performance: (Practical) Limitations and Possible Solutions

    CERN Document Server

    Antoine, Claire Z

    2014-01-01

    This chapter presents in the first part the requirement for the surface preparation of RF Niobium cavities and its justification in term s of physical origin of limitation (e.g. cleanliness and field emission, influence of the surface treatments, morphology and surface damage, etc.). In the second part we discuss the different models describing the ultimate limits of SRF cavities, and we present one of the possible ways to overcome Niobium monopoly toward higher performances.

  17. Data Quality Monitoring Framework for ATLAS Experiment: Performance Achieved with Colliding Beams at LHC

    CERN Document Server

    Corso-Radu, A; The ATLAS collaboration; Ilchenko, Y; Kolos, S; Okawa, H; Slagle, K; Taffard, A

    2010-01-01

    With the delivery of the first proton-proton collisions by the LHC, the ATLAS collaboration had the opportunity to operate the detector under the environment it was designed for. These first runs have been of great interest not only for the high energy physics outcome, but also were used to perform a general commissioning of the system. The online data quality monitoring framework (DQMF) is a highly scalable distributed framework that is used to assess the quality of the data and the operational conditions of the detector, trigger and data acquisition system. DQMF provides quick feedback to the user about the correct functioning and performance of different parts of the detector, it quickly spots problems related with data quality and allows one to determine the origin of these problems. DQMF performs over forty thousand advanced data quality checks at a rate that depends on the histogram update frequency and it displays histograms and results of these checks on several dozens of monitors installed in the mai...

  18. Achievement motivation, competitiveness and sports performance in a team of sportsmen soccer players between 14 and 24 years old

    Directory of Open Access Journals (Sweden)

    Alejo García-Naveira

    2011-05-01

    Full Text Available In order to identify to what extent competitiveness trait is related to sport performance in soccer, and to what extent the age and sport category can influence these variables, a descriptive cross-sectional study has been developed. The variables age, sport category, sport performance, achievement motivation (Me, motivation to avoid the failure (Mef and competitiveness trait have been assessed in 151 men soccer players (between 14 and 24 y.o. of a Spanish sport club. The results indicated that the sport performance ascends with age. Consequently, a direct relationship between the sport category and the performance has been observed. Me, Mef and competitiveness trait have been associated with the performance and has varied based on the sport category. No correlation between Me, Mef, competitiveness and age of the sportsmen has been found

  19. Motivation and performance within a collaborative computer-based modeling task: Relations between students' achievement goal orientation, self-efficacy, cognitive processing and achievement

    NARCIS (Netherlands)

    Sins, P.H.M.; van Joolingen, W.R.; Savelsbergh, E.R.; van Hout-Wolters, B.H.A.M.

    2008-01-01

    Purpose of the present study was to test a conceptual model of relations among achievement goal orientation, self-efficacy, cognitive processing, and achievement of students working within a particular collaborative task context. The task involved a collaborative computer-based modeling task. In ord

  20. Motivation and performance within a collaborative computer-based modeling task: relations between students’ achievement goal orientation, self-efficacy, cognitive processing, and achievement

    NARCIS (Netherlands)

    Sins, Patrick H.M.; Joolingen, van Wouter R.; Savelsbergh, Elwin R.; Hout-Wolters, van Bernadette

    2008-01-01

    Purpose of the present study was to test a conceptual model of relations among achievement goal orientation, self-efficacy, cognitive processing, and achievement of students working within a particular collaborative task context. The task involved a collaborative computer-based modeling task. In ord

  1. A conceptual framework for achieving performance enhancing drug compliance in sport.

    Science.gov (United States)

    Donovan, Robert J; Egger, Garry; Kapernick, Vicki; Mendoza, John

    2002-01-01

    There has been, and continues to be, widespread international concern about athletes' use of banned performance enhancing drugs (PEDs). This concern culminated in the formation of the World Anti-Doping Agency (WADA) in November 1999. To date, the main focus on controlling the use of PEDs has been on testing athletes and the development of tests to detect usage. Although athletes' beliefs and values are known to influence whether or not an athlete will use drugs, little is known about athletes' beliefs and attitudes, and the limited empirical literature shows little use of behavioural science frameworks to guide research methodology, results interpretation, and intervention implications. Mindful of this in preparing its anti-doping strategy for the 2000 Olympics, the Australian Sports Drug Agency (ASDA) in 1997 commissioned a study to assess the extent to which models of attitude-behaviour change in the public health/injury prevention literature had useful implications for compliance campaigns in the sport drug area. A preliminary compliance model was developed from three behavioural science frameworks: social cognition models; threat (or fear) appeals; and instrumental and normative approaches. A subsequent review of the performance enhancing drug literature confirmed that the overall framework was consistent with known empirical data, and therefore had at least face validity if not construct validity. The overall model showed six major inputs to an athlete's attitudes and intentions with respect to performance enhancing drug usage: personality factors, threat appraisal, benefit appraisal, reference group influences, personal morality and legitimacy. The model demonstrated that a comprehensive, fully integrated programme is necessary for maximal effect, and provides anti-doping agencies with a structured framework for strategic planning and implementing interventions. Programmes can be developed in each of the six major areas, with allocation of resources to each

  2. The role of mechanization and integration of manufacturing processes in achieving operational performance

    DEFF Research Database (Denmark)

    Naqvi, Syed Turab Haider; Farooq, Sami; Johansen, John;

    2014-01-01

    Small manufacturing firms are the dominant organization type for most of the developed countries. However, these firms have not been the focus of research and their strategic and operational needs are not extensively addressed by the academic community. Therefore, this research aims at empirically...... finding the impact of mechanization and integration of manufacturing processes and systems on operational performance in small Danish manufacturing firms. We use data of 357 small Danish manufacturing firms and empirically found distinct impact of mechanization and integration of systems on operational...

  3. High-performance gas sensing achieved by mesoporous tungsten oxide mesocrystals with increased oxygen vacancies

    KAUST Repository

    Wang, Dong

    2013-01-01

    The inner structure of W18O49 mesocrystals was observed by electron microscopy with the help of ultramicrotomy and focused ion beam techniques. The results showed that these mesocrystals contain irregular mesopores formed through partial fusion of self-assembled nanowires, and consequently have long-range structural ordering in one dimension and short-range ordering in the other two dimensions. The W18O 49 mesocrystals exhibit superior performance in gas sensing applications, which is considered to be associated with the presence of more oxygen vacancy sites in the unique mesoporous structure. © 2013 The Royal Society of Chemistry.

  4. Studies on the impact of achievement motivation on childrens’ performance in the FEW-2

    Directory of Open Access Journals (Sweden)

    Peggy Beuthan

    2012-09-01

    Full Text Available If children in occupational diagnostics solve tasks with suboptimal test motivation, the results of such tests can be falsified. Against that background, the present research aims were to examine, whether there is an influence of children’s test motivation on their performance in the FEW-2, and if their test motivation can be improved by promising a reward. In an experimental field study of 80 healthy and German-speaking children, at the age of 4 to 6 years, data on test motivation were collected and the FEW-2 was performed. To answer the research questions correlation analysis and t-tests for unpaired samples were carried out. The correlation analyses showed an influence of the motivation of the test on the outcomes of the FEW-2, if the claim of other cognitive services, such as, for example, the concentration of power was increased. According to the findings of the t-tests, the reward did not lead to a heightened test motivation amongst the participants of the experimental group. The revealed influence of test motivation on the outcomes of the FEW-2 underlines the necessity to test for test motivation in view of a reliable and valid neuropsychological diagnostic.

  5. Balance the Carrier Mobility To Achieve High Performance Exciplex OLED Using a Triazine-Based Acceptor.

    Science.gov (United States)

    Hung, Wen-Yi; Chiang, Pin-Yi; Lin, Shih-Wei; Tang, Wei-Chieh; Chen, Yi-Ting; Liu, Shih-Hung; Chou, Pi-Tai; Hung, Yi-Tzu; Wong, Ken-Tsung

    2016-02-01

    A star-shaped 1,3,5-triazine/cyano hybrid molecule CN-T2T was designed and synthesized as a new electron acceptor for efficient exciplex-based OLED emitter by mixing with a suitable electron donor (Tris-PCz). The CN-T2T/Tris-PCz exciplex emission shows a high ΦPL of 0.53 and a small ΔET-S = -0.59 kcal/mol, affording intrinsically efficient fluorescence and highly efficient exciton up-conversion. The large energy level offsets between Tris-PCz and CN-T2T and the balanced hole and electron mobility of Tris-PCz and CN-T2T, respectively, ensuring sufficient carrier density accumulated in the interface for efficient generation of exciplex excitons. Employing a facile device structure composed as ITO/4% ReO3:Tris-PCz (60 nm)/Tris-PCz (15 nm)/Tris-PCz:CN-T2T(1:1) (25 nm)/CN-T2T (50 nm)/Liq (0.5 nm)/Al (100 nm), in which the electron-hole capture is efficient without additional carrier injection barrier from donor (or acceptor) molecule and carriers mobilities are balanced in the emitting layer, leads to a highly efficient green exciplex OLED with external quantum efficiency (EQE) of 11.9%. The obtained EQE is 18% higher than that of a comparison device using an exciplex exhibiting a comparable ΦPL (0.50), in which TCTA shows similar energy levels but higher hole mobility as compared with Tris-PCz. Our results clearly indicate the significance of mobility balance in governing the efficiency of exciplex-based OLED. Exploiting the Tris-PCz:CN-T2T exciplex as the host, we further demonstrated highly efficient yellow and red fluorescent OLEDs by doping 1 wt % Rubrene and DCJTB as emitter, achieving high EQE of 6.9 and 9.7%, respectively. PMID:26820247

  6. Quality of Education Predicts Performance on the Wide Range Achievement Test-4th Edition Word Reading Subtest

    OpenAIRE

    Sayegh, P; Arentoft, A.; Thaler, NS; Dean, AC; Thames, AD

    2014-01-01

    © The Author 2014. Published by Oxford University Press. All rights reserved. The current study examined whether self-rated education quality predicts Wide Range Achievement Test-4th Edition (WRAT-4) Word Reading subtest and neurocognitive performance, and aimed to establish this subtest's construct validity as an educational quality measure. In a community-based adult sample (N = 106), we tested whether education quality both increased the prediction of Word Reading scores beyond demographic...

  7. Achieving enhanced DSSC performance by microwave plasma incorporation of carbon into TiO2 photoelectrodes

    Science.gov (United States)

    Dang, Binh H. Q.; MacElroy, Don; Dowling, Denis P.

    2013-06-01

    The photoactivity of carbon-incorporated titanium dioxide (TiO2) has been widely reported. This study involves a novel approach to the incorporation of carbon into TiO2 through the use of microwave plasma processing. The process involved thermally treating printed TiO2 nanoparticle coatings in a microwave-induced argon-oxygen plasma containing low concentrations of methane. The resulting deposited carbon layer was characterized using XRD, XPS, Raman, UV-vis, ellipsometry, and optical profilometry. It was found that the methane gas was dissociated in the microwave plasma into its carbon species, which were then deposited as a nm-thick layer onto the TiO2 coatings, most likely in the form of graphite. The photovoltaic performances of both the TiO2 and the carbon-incorporated TiO2 were assessed through J-V and IPCE measurements of the N719-sensitized solar cells using the titania as their photoanodes. Up to a 72% improvement in the maximum power density (Pd-max) was observed for the carbon-incorporated TiO2 samples as compared to the TiO2, onto which no carbon was added. This improvement was found to be mainly associated with an increase in the short-circuit current density (Jsc), but independent from the open-circuit voltage (Voc), the filter factor (FF), and the level of dye adsorption. Possible contributory factors to the improved performance of the carbon-incorporated TiO2 were the enhanced electron conductivity and electron lifetime, both of which were elucidated through electrochemical impedance spectroscopy (EIS). When the surface layer was examined using XPS, the optimal carbon content on the TiO2 coating surface was found to be 8.4%, beyond which there was a reduction in the DSSC efficiency.

  8. Achieving enhanced DSSC performance by microwave plasma incorporation of carbon into TiO2 photoelectrodes

    International Nuclear Information System (INIS)

    The photoactivity of carbon-incorporated titanium dioxide (TiO2) has been widely reported. This study involves a novel approach to the incorporation of carbon into TiO2 through the use of microwave plasma processing. The process involved thermally treating printed TiO2 nanoparticle coatings in a microwave-induced argon-oxygen plasma containing low concentrations of methane. The resulting deposited carbon layer was characterized using XRD, XPS, Raman, UV–vis, ellipsometry, and optical profilometry. It was found that the methane gas was dissociated in the microwave plasma into its carbon species, which were then deposited as a nm-thick layer onto the TiO2 coatings, most likely in the form of graphite. The photovoltaic performances of both the TiO2 and the carbon-incorporated TiO2 were assessed through J-V and IPCE measurements of the N719-sensitized solar cells using the titania as their photoanodes. Up to a 72% improvement in the maximum power density (Pd-max) was observed for the carbon-incorporated TiO2 samples as compared to the TiO2, onto which no carbon was added. This improvement was found to be mainly associated with an increase in the short-circuit current density (Jsc), but independent from the open-circuit voltage (Voc), the filter factor (FF), and the level of dye adsorption. Possible contributory factors to the improved performance of the carbon-incorporated TiO2 were the enhanced electron conductivity and electron lifetime, both of which were elucidated through electrochemical impedance spectroscopy (EIS). When the surface layer was examined using XPS, the optimal carbon content on the TiO2 coating surface was found to be 8.4%, beyond which there was a reduction in the DSSC efficiency.

  9. Tuning interactions between zeolite and supported metal by physical-sputtering to achieve higher catalytic performances.

    Science.gov (United States)

    Li, Xin-Gang; Liu, Cheng; Sun, Jian; Xian, Hui; Tan, Yi-Sheng; Jiang, Zheng; Taguchi, Akira; Inoue, Mitsuhiro; Yoneyama, Yoshiharu; Abe, Takayuki; Tsubaki, Noritatsu

    2013-01-01

    To substitute for petroleum, Fischer-Tropsch synthesis (FTS) is an environmentally benign process to produce synthetic diesel (n-paraffin) from syngas. Industrially, the synthetic gasoline (iso-paraffin) can be produced with a FTS process followed by isomerization and hydrocracking processes over solid-acid catalysts. Herein, we demonstrate a cobalt nano-catalyst synthesized by physical-sputtering method that the metallic cobalt nano-particles homogeneously disperse on the H-ZSM5 zeolite support with weak Metal-Support Interactions (MSI). This catalyst performed the high gasoline-range iso-paraffin productivity through the combined FTS, isomerization and hydrocracking reactions. The weak MSI results in the easy reducibility of the cobalt nano-particles; the high cobalt dispersion accelerates n-paraffin diffusion to the neighboring acidic sites on the H-ZSM5 support for isomerization and hydrocracking. Both factors guarantee its high CO conversion and iso-paraffin selectivity. This physical-sputtering technique to synthesize the supported metallic nano-catalyst is a promising way to solve the critical problems caused by strong MSI for various processes. PMID:24085106

  10. Transuranics Laboratory, achievements and performance; Laboratorio de Transuranicos, logros y fundamento

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, C.; Anton, M. P.

    2004-07-01

    The Marine and Aquatic Radioecology Group (MARG) was established in 1985 with the main scope of analysing the consequences of the Palomares accident in the adjacent Mediterranean ecosystem. From then on and up to now , this Group has extended its investigations to other European marine environments, such as the Spanish Mediterranean margin, the Artic and the Atlantic. The main research of long-lived radionuclides (plutonium, americium and Cs-137) determining the orography influence, riverine inputs and their geo-chemical associations. This group is currently accomplishing new challenges on the radioecology field such as the development of techniques for transuranics speciation to determine their geo-chemical association to the main sediment compounds. Natural and anthropogenic radionuclides distribution on salt-marsh areas affected by dry-wet periods is being studied as well as the possibilities of fusing crossed techniques for dating recent sediments (pollen, anthropogenic, ''210 Pb, etc). The Laboratory performance description, the procedures used, calculations, challenges and gaps are described in this report. (Author) 22 refs.

  11. Rankings of International Achievement Test Performance and Economic Strength: Correlation or Conjecture?

    Directory of Open Access Journals (Sweden)

    CHRISTOPHER H. TIENKEN

    2008-04-01

    Full Text Available Examining a popular political notion, this article presents results from a series of Spearman Rho calculations conducted to investigate relationships between countries’ rankings on international tests of mathematics and science and future economic competitiveness as measured by the 2006 World Economic Forum’s Growth Competitiveness Index (GCI. The study investigated the existence of relationships between international test rankings from three different time periods during the last 50 years of U.S. education policy development (i.e., 1957–1982, 1983–2000, and 2001–2006 and 2006 GCI ranks. It extends previous research on the topic by investigating how GCI rankings in the top 50 percent and bottom 50 percent relate to rankings on international tests for the countries that participated in each test. The study found that the relationship between ranks on international tests of mathematics and science and future economic strength is stronger among nations with lower-performing economies. Nations with strong economies, such as the United States, demonstrate a weaker, nonsignificant relationship.

  12. ITC SOLUTIONS TO ACHIEVE PERFORMANCE AND EFFICIENCY OF HEALTH SERVICES: ONLINE VIRTUAL CLINIC

    Directory of Open Access Journals (Sweden)

    Adina BĂLAN

    2010-01-01

    Full Text Available The digital era modified the way people work, how the information and the informational resources are defined and organized. The organization which holds, uses and correctly reproduces the piece of information, the knowledge, the intellectual capital, becomes a leader in the proper field of activity. Following the actual tendencies in the digital era connected to the exchange of professional information, I can say that the exchange and sharing of digital information in a global multitude of interconnected computers are essential instruments that can contribute to the development and consolidation of the intellectual potential of the organization. This is why, the access of the individuals to information is an actual requirement of the development of the Romanian society in the context of globalization and world implication o contemporary processes and phenomena. The Digital integration eliminates the barriers that traditionally suppress the circuit of the medical information, lets the goods and services circulate to and from Romania by promoting efficiency as final purpose. Performance is needed in the health system, the transformation of the system of medical services by bringing the benefits of the medical science and technology to all individuals from every community. In order to accomplish these expectations it is needed that all the components that form the health system look at it as a whole and subscribe to modern solutions for improvement so that the quality of health should raise to an unprecedented level. Even if health systems differ from country to country from the organizational and financial point of view, they face the same challenges and problems, respectively the supply of medical care of better quality and keeping under control the health expenses. The use of information and communication technology in the field of medical assistance in order to stock, share, transmit and analyze clinical data and knowledge is more necessary

  13. Achieving high performance polymer optoelectronic devices for high efficiency, long lifetime and low fabrication cost

    Science.gov (United States)

    Huang, Jinsong

    This thesis described three types of organic optoelectronic devices: polymer light emitting diodes (PLED), polymer photovoltaic solar cell, and organic photo detector. The research in this work focuses improving their performance including device efficiency, operation lifetime simplifying fabrication process. With further understanding in PLED device physics, we come up new device operation model and improved device architecture design. This new method is closely related to understanding of the science and physics at organic/metal oxide and metal oxide/metal interface. In our new device design, both material and interface are considered in order to confine and balance all injected carriers, which has been demonstrated very be successful in increasing device efficiency. We created two world records in device efficiency: 18 lm/W for white emission fluorescence PLED, 22 lm/W for red emission phosphorescence PLED. Slow solvent drying process has been demonstrated to significantly increase device efficiency in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C 61-butyric acid methyl ester (PCBM) mixture polymer solar cell. From the mobility study by time of flight, the increase of efficiency can be well correlated to the improved carrier transport property due to P3HT crystallization during slow solvent drying. And it is found that, similar to PLED, balanced carrier mobility is essential in high efficient polymer solar cell. There is also a revolution in our device fabrication method. A unique device fabrication method is presented by an electronic glue based lamination process combined with interface modification as a one-step polymer solar cell fabrication process. It can completely skip the thermal evaporation process, and benefit device lifetime by several merits: no air reactive. The device obtained is metal free, semi-transparent, flexible, self-encapsulated, and comparable efficiency with that by regular method. We found the photomultiplication (PM) phenomenon in C

  14. Wage Dispersion, Public Sector Wages and the Stagnating Danish Gender Wage Gap

    DEFF Research Database (Denmark)

    Gupta, Nabanita Datta; Oaxaca, Ronald L.; Smith, Nina

    1998-01-01

    The gender wage gap in Denmark has virtually stagnated since the early 70s. This study examines whether this stagnation is mainly due to a changing wage dispersion or to changing prices on observed and unobserved skills. Since about half the female labour force is employed in the public sector, the....... These techniques are applied to a sample of Danish wage earners in the period 1983-94. The decomposition results suggest different explanations behind the stagnation of the gender wage gap in the public and private sectors. The development in average public sector wages is calculated assuming observed...

  15. Stagnating Jatropha Biofuel Development in Southwest China: An Institutional Approach

    Directory of Open Access Journals (Sweden)

    Jia Li

    2014-05-01

    Full Text Available Biodiesel from jatropha has been considered as a promising alternative to fossil fuels for some time. Consequently, China started promoting jatropha as one of the options to meet its ever-increasing energy consumption, and the Chinese biodiesel industry also gained interest. However, the excitement of the biofuel industry in jatropha faded after it did not bring about the expected results. This article investigates the stagnation in jatropha development and production for biodiesel in China, using two detailed case studies of jatropha biofuel production in southeast China. It is found that the underdeveloped biodiesel policy and regulation, such as a rather late formulation of standards for biodiesel (especially the B5 and the absence of mandatory targets, is an important reason for hampering jatropha development. Besides that, lack of financial support undermined sustained jatropha planting at the farm level and lack of sustained commitment from state-owned enterprises or private companies over a long time span further contributed to jatropha project’s failure. Better implementation of the rule of law, mandatory blending requirements, hazard insurance, as well as continuous financial support, might improve the continuation of jatropha plantation schemes.

  16. Rise, stagnation, and rise of Danish women's life expectancy.

    Science.gov (United States)

    Lindahl-Jacobsen, Rune; Rau, Roland; Jeune, Bernard; Canudas-Romo, Vladimir; Lenart, Adam; Christensen, Kaare; Vaupel, James W

    2016-04-12

    Health conditions change from year to year, with a general tendency in many countries for improvement. These conditions also change from one birth cohort to another: some generations suffer more adverse events in childhood, smoke more heavily, eat poorer diets, etc., than generations born earlier or later. Because it is difficult to disentangle period effects from cohort effects, demographers, epidemiologists, actuaries, and other population scientists often disagree about cohort effects' relative importance. In particular, some advocate forecasts of life expectancy based on period trends; others favor forecasts that hinge on cohort differences. We use a combination of age decomposition and exchange of survival probabilities between countries to study the remarkable recent history of female life expectancy in Denmark, a saga of rising, stagnating, and now again rising lifespans. The gap between female life expectancy in Denmark vs. Sweden grew to 3.5 y in the period 1975-2000. When we assumed that Danish women born 1915-1945 had the same survival probabilities as Swedish women, the gap remained small and roughly constant. Hence, the lower Danish life expectancy is caused by these cohorts and is not attributable to period effects.

  17. Predictive Gust Load Alleviation Control Using Leading Edge Stagnation Point Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ZONA Technology, Inc proposes an R&D effort to develop a Gust Load Alleviation (GLA) control system using a novel Leading Edge Stagnation Point (LESP) sensor...

  18. Safe, Non-Corrosive Dielectric Fluid for Stagnating Radiator Thermal Control System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Paragon proposes to develop a single-loop, non-toxic, stagnating active pumped loop thermal control design for NASA's Orion or Lunar Surface Access Module (LSAM)...

  19. Analytic Solution for Magnetohydrodynamic Stagnation Point Flow towards a Stretching Sheet

    Institute of Scientific and Technical Information of China (English)

    DING Qi; ZHANG Hong-Qing

    2009-01-01

    A steady two-dimensional magnetohydrodynamic stagnation point flow towards a stretching sheet with variable surface temperature is investigated. The analytic solution is obtained by homotopy analysis method. Theconvergence region is computed and the feature of the solution is discussed.

  20. Safe, Non-Corrosive Dielectric Fluid for Stagnating Radiator Thermal Control System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Paragon Space Development Corporation proposes to develop a single-loop, non-toxic, active pumped radiator design with robust, reliable operation near stagnation...

  1. Achieving high performance in intermediate temperature direct carbon fuel cells with renewable carbon as a fuel source

    International Nuclear Information System (INIS)

    Highlights: • Bamboo fiber and waste paper were pyrolyzed to generate bamboo carbon and waste paper carbon as anode fuels of IT-DCFC. • Superior cell performance was achieved with the waste paper carbon. • The results suggested the high performance was due to the highest thermal reactivity and the catalytic inherent impurities. • Calcite and kaolinite as inherent impurities favored the thermal decomposition and the electrooxidation of carbon. - Abstract: Three kinds of carbon sources obtained from carbon black, bamboo fiber and waste paper were investigated as anode fuels in an intermediate temperature direct carbon fuel cell. The carbon sources were characterized with X-ray photoelectron spectroscopy, thermal gravimetric analysis, etc. The results indicated that the waste paper carbon was more abundant in calcite and kaolinite, and showed higher thermal reactivity in the intermediate temperature range compared with the other two carbon sources. The cell performance was tested at 650 °C in a hybrid single cell, using Sm0.20Ce0.80O2−x as the electrolyte. As a result, the cell fed with waste paper carbon showed the highest performance among the three carbon sources, with a peak power density of 225 mW cm−2. The results indicated that its inherent impurities, such as calcite and kaolinite, might favor the thermal gasification of renewable carbon sources, which resulted in the enhanced performance of the intermediate temperature direct carbon fuel cell

  2. Multimedia OC12 parallel interface using VCSEL array to achieve high-performance cost-effective optical interconnections

    Science.gov (United States)

    Chang, Edward S.

    1996-09-01

    ribbon cable, and MT connectors to achieve a high-performance, low-cost parallel link. A logical model of a multimedia server with parallel connections to an ATM switch, and to clients is presented. The design of the parallel optical link is analyzed. Furthermore, the link configured for testing, the test method, and test results are presented to confirm the analysis and to assure reliable link performance.

  3. Quality of education predicts performance on the Wide Range Achievement Test-4th Edition Word Reading subtest.

    Science.gov (United States)

    Sayegh, Philip; Arentoft, Alyssa; Thaler, Nicholas S; Dean, Andy C; Thames, April D

    2014-12-01

    The current study examined whether self-rated education quality predicts Wide Range Achievement Test-4th Edition (WRAT-4) Word Reading subtest and neurocognitive performance, and aimed to establish this subtest's construct validity as an educational quality measure. In a community-based adult sample (N = 106), we tested whether education quality both increased the prediction of Word Reading scores beyond demographic variables and predicted global neurocognitive functioning after adjusting for WRAT-4. As expected, race/ethnicity and education predicted WRAT-4 reading performance. Hierarchical regression revealed that when including education quality, the amount of WRAT-4's explained variance increased significantly, with race/ethnicity and both education quality and years as significant predictors. Finally, WRAT-4 scores, but not education quality, predicted neurocognitive performance. Results support WRAT-4 Word Reading as a valid proxy measure for education quality and a key predictor of neurocognitive performance. Future research should examine these findings in larger, more diverse samples to determine their robust nature.

  4. Case study: Comparison of motivation for achieving higher performance between self-directed and manager-directed aerospace engineering teams

    Science.gov (United States)

    Erlick, Katherine

    "The stereotype of engineers is that they are not people oriented; the stereotype implies that engineers would not work well in teams---that their task emphasis is a solo venture and does not encourage social aspects of collaboration" (Miner & Beyerlein, 1999, p. 16). The problem is determining the best method of providing a motivating environment where design engineers may contribute within a team in order to achieve higher performance in the organization. Theoretically, self-directed work teams perform at higher levels. But, allowing a design engineer to contribute to the team while still maintaining his or her anonymity is the key to success. Therefore, a motivating environment must be established to encourage greater self-actualization in design engineers. The purpose of this study is to determine the favorable motivational environment for design engineers and describe the comparison between two aerospace design-engineering teams: one self-directed and the other manager directed. Following the comparison, this study identified whether self-direction or manager-direction provides the favorable motivational environment for operating as a team in pursuit of achieving higher performance. The methodology used in this research was the case study focusing on the team's levels of job satisfaction and potential for higher performance. The collection of data came from three sources, (a) surveys, (b) researcher observer journal and (c) collection of artifacts. The surveys provided information regarding personal behavior characteristics, potentiality for higher performance and motivational attributes. The researcher journal provided information regarding team dynamics, individual interaction, conflict and conflict resolution. The milestone for performance was based on the collection of artifacts from the two teams. The findings from this study illustrated that whether the team was manager-directed or self-directed does not appear to influence the needs and wants of the

  5. Intellectual and non-intellectual determinants of high academic achievement – the contribution of personality traits to the assessment of high performance potential

    Directory of Open Access Journals (Sweden)

    Silvia Schubhart

    2013-09-01

    Full Text Available In this paper a study is presented which tries to explain and predict high academic achievement in children or adolescents on the basis of intellectual and non-intellectual determinants – in this case, performance relevant personality traits as well as the social environment of stimulation. The prognosis of high academic achievement is based on a new diagnostic model, the Viennese Diagnostic Model of High Achievement Potential, which undergoes its first empirical validation here. The results show impressive evidence that performance-relevant personality traits and categories of social environment of stimulation contribute to high academic achievement in children and adolescents of above-average intelligence.

  6. Intellectual and non-intellectual determinants of high academic achievement – the contribution of personality traits to the assessment of high performance potential

    OpenAIRE

    Silvia Schubhart; Stefana Holocher-Ertl; Georg Wilflinger

    2013-01-01

    In this paper a study is presented which tries to explain and predict high academic achievement in children or adolescents on the basis of intellectual and non-intellectual determinants – in this case, performance relevant personality traits as well as the social environment of stimulation. The prognosis of high academic achievement is based on a new diagnostic model, the Viennese Diagnostic Model of High Achievement Potential, which undergoes its first empirical validation here. The resu...

  7. MHD Stagnation Flow of a Newtonian Fluid towards a Uniformly Heated and Moving Vertical Plate

    Directory of Open Access Journals (Sweden)

    Mehmet Şirin Demir

    2016-01-01

    Full Text Available Stagnation flow of an electrically conducting incompressible viscous fluid towards a moving vertical plate in the presence of a constant magnetic field is investigated. By using the appropriate transformations for the velocity components and temperature, the partial differential equations governing flow and heat transfer are reduced to a set of nonlinear ordinary differential equations. These equations are solved approximately using a numerical technique for the following two problems: (i two-dimensional stagnation-point flow on a moving vertical plate, (ii axisymmetric stagnation-point flow on a moving vertical plate. The effects of non-dimensional parameters on the velocity components, wall shear stresses, temperature and heat transfer are examined carefully.

  8. A strategy for reducing stagnation phase hydrodynamic instability growth in inertial confinement fusion implosions

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D. S.; Robey, H. F.; Smalyuk, V. A. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)

    2015-05-15

    Encouraging progress is being made in demonstrating control of ablation front hydrodynamic instability growth in inertial confinement fusion implosion experiments on the National Ignition Facility [E. I. Moses, R. N. Boyd, B. A. Remington, C. J. Keane, and R. Al-Ayat, Phys. Plasmas 16, 041006 (2009)]. Even once ablation front stabilities are controlled, however, instability during the stagnation phase of the implosion can still quench ignition. A scheme is proposed to reduce the growth of stagnation phase instabilities through the reverse of the “adiabat shaping” mechanism proposed to control ablation front growth. Two-dimensional radiation hydrodynamics simulations confirm that improved stagnation phase stability should be possible without compromising fuel compression.

  9. Gender Differences in Achievement Goals and Performances in English Language and Mathematics of Senior Secondary Schools Students in Borno State, Nigeria

    Science.gov (United States)

    Musa, Alice K. J.; Dauda, Bala; Umar, Mohammad A.

    2016-01-01

    The paper investigated gender difference in achievement goals and performance in English Language and Mathematics of senior secondary schools students in Borno State, Nigeria. The study specifically sought to determine gender differences in students' academic performances in English Language, Mathematics and overall academic performance as well as…

  10. Achievement Gaps: How Hispanic and White Students in Public Schools Perform in Mathematics and Reading on the National Assessment of Educational Progress. Highlights. NCES 2011-485

    Science.gov (United States)

    National Center for Education Statistics, 2011

    2011-01-01

    This report provides a detailed portrait of Hispanic and White academic achievement gaps and how students' performance has changed over time at both the national and state levels. The report presents achievement gaps using reading and mathematics assessment data from the National Assessment of Educational Progress (NAEP) for the 4th- and 8th-grade…

  11. DTC-SVM Based on PI Torque and PI Flux Controllers to Achieve High Performance of Induction Motor

    Directory of Open Access Journals (Sweden)

    Hassan Farhan Rashag

    2014-01-01

    Full Text Available The fundamental idea of direct torque control of induction machines is investigated in order to emphasize the property produced by a given voltage vector on stator flux and torque variations. The proposed control system is based on Space Vector Modulation (SVM of electrical machines, Improvement model reference adaptive system, real time of stator resistance and estimation of stator flux. The purpose of this control is to minimize electromagnetic torque and flux ripple and minimizing distortion of stator current. In this proposed method, PI torque and PI flux controller are designed to achieve estimated torque and flux with good tracking and fast response with reference torque and there is no steady state error. In addition, design of PI torque and PI flux controller are used to optimize voltages in d-q reference frame that applied to SVM. The simulation Results of proposed DTC-SVM have complete excellent performance in steady and transient states as compared with classical DTC-SVM.

  12. Performance Assessment of High and Low Income Families through "Online RAW Achievement Battery Test" of Primary Grade Students

    Science.gov (United States)

    Ahmed, Tamim; Hanif, Maria

    2016-01-01

    This study is intended to investigate student's achievement capability among two families i.e. Low and High income families and designed for primary level learners. A Reading, Arithmetic and Writing (RAW) Achievement test that was developed as a part of another research study (Tamim Ahmed Khan, 2015) was adopted for this study. Both English medium…

  13. A Multi-Institutional Study of the Relationship between High School Mathematics Achievement and Performance in Introductory College Statistics

    Science.gov (United States)

    Dupuis, Danielle N.; Medhanie, Amanuel; Harwell, Michael; LeBeau, Brandon; Monson, Debra; Post, Thomas R.

    2012-01-01

    In this study we examined the effects of prior mathematics achievement and completion of a commercially developed, National Science Foundation-funded, or University of Chicago School Mathematics Project high school mathematics curriculum on achievement in students' first college statistics course. Specifically, we examined the relationship between…

  14. Craft-Joule Project: Stagnation proof transparently insulated flat plate solar collector (static)

    Energy Technology Data Exchange (ETDEWEB)

    Oliva, A; Cadafalch, J; Perez-Segarra, C.D. [Universitat Politecnica de Catalunya, Barcelona (Spain)] (and others)

    2000-07-01

    The STATIC (STAgnation proof Transparently Insulated flat plate Solar Collector) project is a Craft-Joule Project within the framework of the Non Nuclear Energy Programme Joule III coordinated by the Centre Technologic de Transferencia de Calor (CTTC). The core group of SMEs involved in the project has its main economical activity in the field of solar thermal systems at low temperature level (domestic hot water, solar heating, etc.). Beyond this, a large application potential exists for solar heating at medium temperature level (from 80 to 160 Celsius degrees) : industrial process heat, solar cooling and air conditioning, solar drying , distillation and desalination. Three of the four SME proposers are located in Southern Europe and in the Caribean, where a continuos increase of the demand for air conditioning and cooling has been demonstrated in the last years. The recent development of flat plate solar collectors with honeycomb-type transparent insulation cover has shown that this type of collectors can become a low cost alternative to evacuated tube and high concentrating CPC collectors in the medium temperature range from 80 to 160 Celsius degrees. With the expected reduction of collector cost, that forms 30%-50% of total system cost, a decisive break-through of solar thermal systems using heat in the medium temperature range can be achieved. The feasibility and good performance of these solar collectors has been proved in several prototypes. Nevertheless, up to now no commercial products are available. In order to reach this, the following developments of new concepts are necessary and are being carried out within this project: solution of the problem of overheating: development of collector versions for different working temperatures: optimization of the design with the support of high level numerical simulation. Several prototypes of the new solar collectors are being tested. System tests will also be carried or for two test arrays of optimized collector

  15. Invalidating stagnation theory for family owned businesses : comparing family-to-family and third party ownership transfers

    NARCIS (Netherlands)

    Heaver, Roger; Ibrahimovic, Alija; Teeffelen, Lex van

    2015-01-01

    Miller, Le Breton-Miller and Scholnick (2008) summarize and discuss two major perspectives constructed from the literature on family owned businesses (FOBs): stewardship and stagnation theory. In this paper the stagnation theory is being put to the test on Dutch small/medium enterprises (SMEs). Acco

  16. Economic stagnation postponed: background of the 2008 financial-economic crisis in the European Union and the United States

    NARCIS (Netherlands)

    G. Reuten

    2011-01-01

    The significant increase since the early 1980s in the share of income accruing to capital (rather than labor), in both the United States and the European Union, created the potential for economic stagnation. Stagnation was postponed, however, by the development of the banking sector in these countri

  17. Large eddy simulation of premixed and non-premixed combustion in a Stagnation Point Reverse Flow combustor

    Science.gov (United States)

    Undapalli, Satish

    A new combustor referred to as Stagnation Point Reverse Flow (SPRF) combustor has been developed at Georgia Tech to meet the increasingly stringent emission regulations. The combustor incorporates a novel design to meet the conflicting requirements of low pollution and high stability in both premixed and non-premixed modes. The objective of this thesis work is to perform Large Eddy Simulations (LES) on this lab-scale combustor and elucidate the underlying physics that has resulted in its excellent performance. To achieve this, numerical simulations have been performed in both the premixed and non-premixed combustion modes, and velocity field, species field, entrainment characteristics, flame structure, emissions, and mixing characteristics have been analyzed. Simulations have been carried out first for a non-reactive case to resolve relevant fluid mechanics without heat release by the computational grid. The computed mean and RMS quantities in the non-reacting case compared well with the experimental data. Next, the simulations were extended for the premixed reactive case by employing different sub-grid scale combustion chemistry closures: Eddy Break Up (EBU), Artificially Thickened Flame (TF) and Linear Eddy Mixing (LEM) models. Results from the EBU and TF models exhibit reasonable agreement with the experimental velocity field. However, the computed thermal and species fields have noticeable discrepancies. Only LEM with LES (LEMLES), which is an advanced scalar approach, has been able to accurately predict both the velocity and species fields. Scalar mixing plays an important role in combustion, and this is solved directly at the sub-grid scales in LEM. As a result, LEM accurately predicts the scalar fields. Due to the two way coupling between the super-grid and sub-grid quantities, the velocity predictions also compare very well with the experiments. In other approaches, the sub-grid effects have been either modeled using conventional approaches (EBU) or need

  18. On the Analytical Solution of Non-Orthogonal Stagnation Point Flow towards a Stretching Sheet

    DEFF Research Database (Denmark)

    Kimiaeifar, Amin; Bagheri, G. H.; Barari, Amin;

    2011-01-01

    An analytical solution for non-orthogonal stagnation point for the steady flow of a viscous and incompressible fluid is presented. The governing nonlinear partial differential equations for the flow field are reduced to ordinary differential equations by using similarity transformations existed i...

  19. An application of interacting shear flows theory: exact solution for unsteady oblique stagnation point flow

    Institute of Scientific and Technical Information of China (English)

    Guibo Li; Minguo Dai; Zhi Gao

    2006-01-01

    An analytical solution of the governing equations of the interacting shear flows for unsteady oblique stagnation point flow is obtained. It has the same form as that of the exact solution obtained from the complete NS equations and physical analysis and relevant discussions are then presented.

  20. Stagnation-point flow of the Walters' B' fluid with slip

    Directory of Open Access Journals (Sweden)

    F. Labropulu

    2004-01-01

    Full Text Available The steady two-dimensional stagnation point flow of a non-Newtonian Walters' B' fluid with slip is studied. The fluid impinges on the wall either orthogonally or obliquely. A finite difference technique is employed to obtain solutions.

  1. TCM Treatment of Lumbago Due to Qi Stagnation in the Liver and Gallbladder

    Institute of Scientific and Technical Information of China (English)

    王彦辉

    2004-01-01

    @@ As we know, lumbago falls into the category of bi syndrome. It is mainly caused by the external pathogens, such as wind, cold, heat or dampness in the meridians and collaterals. Actually, the emotional disorder, and Zang and Fu damage can also lead to liver stagnation and finally the bi syndrome.

  2. Prediction and experimental validation of stagnation temperature attained by a solar cooker of hot box type

    Energy Technology Data Exchange (ETDEWEB)

    Narasimha Rao, A. V; Srikrishna, D. V. N [Warangal (India)

    2000-07-01

    A hot box type solar cooker, having double glass covers and a plane mirror reflector, is tested for stagnation temperature. A computer code is developed based on the analytical model proposed by Vaishya et. al. The global and beam components of solar radiation measured at Warangal are made use to predict the stagnation temperature of the cooker. The observed values of stagnation temperature at Warangal are compared with those of predicted values. A good agreement of the measured and observed values of the stagnation temperature is observed during the afternoon period. The lag in the observed values during the forenoon may be due to thermal inertia of the cooker. [Spanish] Se probo una estufa solar de tipo caja caliente con cubiertas dobles de vidrio y un espejo reflector plano para medir la temperatura de estancamiento. Se desarrollo un codigo de computacion basado en el modelo analitico propuesto por Vaishya et. al. Los componentes de la radiacion solar globales y de rayo medidos en Warangal se usan para predecir la temperatura de estancamiento de la estufa. Los valores observados de la temperatura de estancamiento en Warangal se comparan con los valores predichos. Se aprecia una buena concidencia de los valores medidos y observados de la temperatura de estancamiento durante el periodo de la tarde. El retraso de los valores observados durante la manana puede ser debido a la inercia termica de la estufa.

  3. What Explains the Stagnation of Female Labor Force Participation in Urban India?

    NARCIS (Netherlands)

    Klasen, S.; Pieters, J.

    2015-01-01

    Female labor force participation rates in urban India between 1987 and 2011 are surprisingly low and have stagnated since the late 1980s. Despite rising growth, fertility decline, and rising wage and education levels, married women's labor force participation hovered around 18 percent. Analysis of f

  4. A meta-analytic review of the approach-avoidance achievement goals and performance relationships in the sport psychology literature

    Directory of Open Access Journals (Sweden)

    Marc Lochbaum

    2015-06-01

    Conclusion: The performance goal contrast holds value for sport performance research. Contrary to approach-avoidance predictions, the mastery-approach goal and performance effect size was significant and of equal magnitude as the performance approach goal and performance effect size. Thus, future research should closely test the efficacy of both the mastery- and performance contrasts in impacting performance of sport tasks. Last, the significant effect sizes reported in this review are in stark contrast to contemporary meta-analytic findings in education. Differences in the approach-avoidance goals in sport and education relative to performance should be researched further.

  5. Fifteen Years of Collaborative Innovation and Achievement: NASA Nebraska Space Grant Consortium 15-Year Program Performance and Results Report

    Science.gov (United States)

    Schaaf, Michaela M.; Bowen, Brent D.; Fink, Mary M.; Nickerson, Jocelyn S.; Avery, Shelly; Carstenson, Larry; Dugan, James; Farritor, Shane; Joyce, James; Rebrovich, Barb

    2003-01-01

    Condensing five years of significant work into a brief narrative fitting PPR requirements gave the affiliates of the Nebraska Space Grant a valuable chance for reflection. Achievements of Space Grant in Nebraska were judiciously chosen for this document that best illustrate the resultant synergism of this consortium, keeping in mind that these examples are only a representation of greater activity throughout the state. Following are highlights of many of the finer and personal achievements for Nebraska Space Grant. The Consortium welcomes inquiries to elaborate on any of these accomplishments.

  6. Student Achievement Gaps in High-Performing Schools: Differences as a Function of the Professional Staff as a Learning Community.

    Science.gov (United States)

    Cowley, Kimberly S.; Meehan, Merrill L.

    This study investigated differences among professional staff members' commitment to continuous learning and improvement in high-performing schools differentiated by student academic performance and disaggregated by race and socioeconomic status. A total of 48 high-performing schools were identified by Kentucky Department of Education staff based…

  7. Staying with the Text: The Contribution of Gender, Achievement Orientations, and Interest to Students' Performance on a Literacy Task

    Science.gov (United States)

    Graham, Jedda; Tisher, Ruth; Ainley, Mary; Kennedy, Gregor

    2008-01-01

    This study addresses concerns about boys' underperformance on literacy tasks compared to girls, by investigating male and females students' responses to narrative texts. Participants were 142 Grade 9 and 10 students. Achievement orientations, including goals, self-efficacy, and self-handicapping, were measured and approach and avoidance factors…

  8. Founders and Financially Affiliated Directors on Charter School Boards and Their Impact on Financial Performance and Academic Achievement

    OpenAIRE

    Charisse A. Gulosin; Elif Sisli-Ciamarra

    2012-01-01

    This study uses a hand-collected dataset for charter school boards in Massachusetts between 2001 and 2009 to examine the relationship between financial performance and the presence of founders and financially affiliated directors. School-level financial performance suggests that founder presence on a board has a negative effect on both financial and academic performance of a charter school. On the other hand, the presence of financially affiliated directors on the charter school governing boa...

  9. The Effects of Intercollegiate Athletic Participation on Student Academic Achievement and Leadership Performance in a Selective Institution

    Science.gov (United States)

    Yunker, Craig Andrew

    2009-01-01

    The purpose of this study was to examine the influence of various intensity levels of athletic participation on academic and leadership performance in a selective institution. For the purpose of this study a retrospective analysis of existing admissions and student performance data was conducted. The continuous dependent variables were academic…

  10. The Effect of Performance-Pay in Little Rock, Arkansas on Student Achievement. Working Paper 2008-02

    Science.gov (United States)

    Winters, Marcus; Greene, Jay P.; Ritter, Gary; Marsh, Ryan

    2008-01-01

    This paper examines evidence from a performance-pay program implemented in five Little Rock, Arkansas elementary schools between 2004 and 2007. Using a differences-in-differences approach, the evidence shows that students whose teachers were eligible for performance pay made substantially larger test score gains in math, reading, and language than…

  11. The effect of retesting on end-of-semester performance in high school chemistry at three levels of previous science achievement

    Science.gov (United States)

    Deboer, George E.

    To determine the effect of retesting on student learning in chemistry, three questions were addressed by means of a 3 × 2 (achievement level X treatment) factorial design: (1) Does retesting affect differently the end-of-semester mastery of course objectives of students who are grouped according to their previous achievement in science? (2) Do students who are given an opportunity to take retests merely delay their studying and perform at a lower level on initial tests than nonretested students? (3) Is the procrastination of retested students (if it exists) affected by their achievement level? The results showed that for one of four units low ability students who were retested demonstrated greater learning gains than low ability students who were not retested, and that procrastination, if it was present, did not have significant effects on student learning at any achievement level. Results were discussed in terms of the students' room for improvement, motivation to improve, and ability to improve.

  12. Patterns and Predictors of Adolescent Academic Achievement and Performance in a Sample of Children with Attention-Deficit/Hyperactivity Disorder (ADHD)

    OpenAIRE

    Langberg, Joshua M.; Molina, Brooke S. G.; Arnold, L. Eugene; Epstein, Jeffery N.; Altaye, Mekibib; Hinshaw, Stephen P.; Swanson, James M.; Wigal, Timothy; Hechtman, Lily

    2011-01-01

    Examined predictors of academic achievement, measured by standardized test scores, and performance, measured by school grades, in adolescents (Mage=16.8 yr) who met diagnostic criteria for ADHD-Combined type in early childhood (Mage = 8.5; N = 579). Several mediation models were also tested to determine whether ADHD medication use, receipt of special education, classroom performance, homework completion, or homework management mediated the relationship between symptoms of ADHD and academic ou...

  13. Long-term costs of inflated self-estimate on academic performance among adolescent students: a case of second-language achievements.

    Science.gov (United States)

    Yang, Mu-Li; Chuang, Hsueh-Hua; Chiou, Wen-Bin

    2009-12-01

    Past studies suggest that the adaptive or maladaptive consequences of inflated self-estimate, one form of positive illusions, require further investigation. 308 freshmen at a junior college (164 women, 144 men; M age = 19.8 yr., SD = 1.1) participated in a longitudinal study during a 2-yr. period. There were three assessments of short- and long-term effects of overly positive self-estimates on second-language achievement. Students' overestimation of subsequent performance appears to be associated with lower achievement. Those students with apparently inflated self-estimates performed marginally better on the first assessment but worse in the second and final assessments. Students with more accurate self-estimates showed improvement on all assessments. The findings suggested that overinflated self-estimates, i.e., positive illusions, among adolescent students might lead to a lower achievement over the long-term.

  14. Microfluidic-based single cell trapping using a combination of stagnation point flow and physical barrier

    Science.gov (United States)

    Yu, Miao; Chen, Zongzheng; Xiang, Cheng; Liu, Bo; Xie, Handi; Qin, Kairong

    2016-06-01

    Single cell trapping in vitro by microfluidic device is an emerging approach for the study of the relationship between single cells and their dynamic biochemical microenvironments. In this paper, a hydrodynamic-based microfluidic device for single cell trapping is designed using a combination of stagnation point flow and physical barrier. The microfluidic device overcomes the weakness of the traditional ones, which have been only based upon either stagnation point flows or physical barriers, and can conveniently load dynamic biochemical signals to the trapped cell. In addition, it can connect with a programmable syringe pump and a microscope to constitute an integrated experimental system. It is experimentally verified that the microfluidic system can trap single cells in vitro even under flow disturbance and conveniently load biochemical signals to the trapped cell. The designed micro-device would provide a simple yet effective experimental platform for further study of the interactions between single cells and their microenvironments.

  15. Mechanism and numerical simulation of pressure stagnation during water jetting perforation

    Institute of Scientific and Technical Information of China (English)

    Huang Zhongwei; Li Gensheng; Tian Shouceng; Shen Zhonghou; Luo Hongbin

    2008-01-01

    When perforating with an abrasive water jet, it is possible that the pressure in the hole (perforation) will be higher than that in the annulus because of water jet blasting against the hole wall,which also is the theoretical basis for the technology of hydro-jet fracturing. This paper analyzes the mechanism of generating pressure stagnation in water jet hole, and puts forward a new concept of hydroseal. Then, the distribution of pressure in the hole was simulated with the finite element method. The simulation results showed that the pressure in the hole was higher than that in the annulus. Also, the lower the annular pressure (confining pressure) and the higher the blasting pressure, the greater the pressure difference. An experiment indicated that the cement sample was lifted up under the pressure stagnation in the hole, which proved the finite element simulation results obviously.

  16. A numerical study of hypersonic stagnation heat transfer predictions at a coordinate singularity

    Science.gov (United States)

    Grasso, Francesco; Gnoffo, Peter A.

    1990-01-01

    The problem of grid induced errors associated with a coordinate singularity on heating predictions in the stagnation region of a three-dimensional body in hypersonic flow is examined. The test problem is for Mach 10 flow over an Aeroassist Flight Experiment configuration. This configuration is composed of an elliptic nose, a raked elliptic cone, and a circular shoulder. Irregularities in the heating predictions in the vicinity of the coordinate singularity, located at the axis of the elliptic nose near the stagnation point, are examined with respect to grid refinement and grid restructuring. The algorithm is derived using a finite-volume formulation. An upwind-biased total-variation diminishing scheme is employed for the inviscid flux contribution, and central differences are used for the viscous terms.

  17. Modeling of Aerobrake Ballute Stagnation Point Temperature and Heat Transfer to Inflation Gas

    Science.gov (United States)

    Bahrami, Parviz A.

    2012-01-01

    A trailing Ballute drag device concept for spacecraft aerocapture is considered. A thermal model for calculation of the Ballute membrane temperature and the inflation gas temperature is developed. An algorithm capturing the most salient features of the concept is implemented. In conjunction with the thermal model, trajectory calculations for two candidate missions, Titan Explorer and Neptune Orbiter missions, are used to estimate the stagnation point temperature and the inflation gas temperature. Radiation from both sides of the membrane at the stagnation point and conduction to the inflating gas is included. The results showed that the radiation from the membrane and to a much lesser extent conduction to the inflating gas, are likely to be the controlling heat transfer mechanisms and that the increase in gas temperature due to aerodynamic heating is of secondary importance.

  18. Eating the right amount of fish: Inverted U-shape association between fish consumption and cognitive performance and academic achievement in Dutch adolescents

    NARCIS (Netherlands)

    De Groot, Renate; Ouwehand, Carolijn; Jolles, Jelle

    2012-01-01

    De Groot, R. H. M., Ouwehand, C., & Jolles, J. (2012). Eating the right amount of fish: Inverted U-shape association between fish consumption and cognitive performance and academic achievement in Dutch adolescents. Prostaglandins, Leukotrienes, and Essential Fatty Acids, 86(3), 113-117. doi:10.1016/

  19. Eating the right amount of fish: Inverted U-shape association between fish consumption and cognitive performance, and academic achievement in Dutch adolescents

    NARCIS (Netherlands)

    De Groot, Renate; Ouwehand, Carolijn; Jolles, Jelle

    2012-01-01

    De Groot, R. H. M., Ouwehand, C., & Jolles, J. (2011, 2 September). Eating the right amount of fish: Inverted U-shape association between fish consumption and cognitive performance and academic achievement in Dutch adolescents. Poster presented at the the 14th biannual EARLI conference, Exeter, Unit

  20. Eating the right amount of fish: Inverted U-shape association between fish consumption and cognitive performance, and academic achievement in Dutch adolescents

    NARCIS (Netherlands)

    De Groot, Renate; Ouwehand, Carolijn; Jolles, Jelle

    2012-01-01

    De Groot, R. H. M., Ouwehand, C., & Jolles, J. (2012, May). Eating the right amount of fish: Inverted U-shape association between fish consumption and cognitive performance, and academic achievement in Dutch adolescents. Paper presented at the 10th Congress of the International Society for the Study

  1. Building trust through promises and performance. Can your organization achieve the stellar results and employee loyalty found at Southwest Airlines?

    Science.gov (United States)

    O'Connor, Edward J; Annison, Michael H

    2002-01-01

    Establishing a trusting relationship with your employees can help you transform your organization into a top performer. Examine how well-defined visions and goals are some of the keys to building that trust. PMID:11806234

  2. TRANSFORMATION VERSUS STAGNATION IN THE OIL PALM INDUSTRY: A COMPARISON BETWEEN MALAYSIA AND NIGERIA

    OpenAIRE

    Kajisa, Kei; Maredia, Mywish K.; Boughton, Duncan

    1997-01-01

    This paper contrasts the successful transformation of the oil palm sector in Malaysia with the stagnation of the oil palm sector in Nigeria, and examines the factors determining the different paths that the oil palm sectors took in these two countries with the aim of drawing lessons for future development and transfer strategy in Nigeria. Comparing two countries in different regions is not easy, especially when Nigeria has been in political chaos and the agro-climatic environments for oil-pal...

  3. Flow and heat transfer at a general three-dimensional stagnation point in a nanofluid

    Energy Technology Data Exchange (ETDEWEB)

    Bachok, Norfifah [Department of Mathematics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Ishak, Anuar, E-mail: anuarishak@yahoo.co [School of Mathematical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Institute of Mathematical Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Nazar, Roslinda [School of Mathematical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Pop, Ioan [Faculty of Mathematics, University of Cluj, R-3400 Cluj, CP 253 (Romania)

    2010-12-15

    The problem dealing with steady three-dimensional stagnation point flow in a nanofluid is investigated. By using appropriate transformation for velocity and temperature, the basic equations governing the flow and heat transfer are reduced to a set of ordinary differential equations. These equations subjected to the associated boundary conditions are then solved numerically. The effects of the nanoparticle volume fraction {phi} and the ratio of the gradient of velocities c on the flow and heat transfer characteristics are thoroughly examined.

  4. Stagnation-Point Flow towards a Stretching Vertical Sheet with Slip Effects

    OpenAIRE

    Khairy Zaimi; Anuar Ishak

    2016-01-01

    The effects of partial slip on stagnation-point flow and heat transfer due to a stretching vertical sheet is investigated. Using a similarity transformation, the governing partial differential equations are reduced into a system of nonlinear ordinary differential equations. The resulting equations are solved numerically using a shooting method. The effect of slip and buoyancy parameters on the velocity, temperature, skin friction coefficient and the local Nusselt number are graphically presen...

  5. Heat flux measurements in stagnation point methane/air flames with thermographic phosphors

    Science.gov (United States)

    Salem, Mohamed; Staude, Susanne; Bergmann, Ulf; Atakan, Burak

    2010-10-01

    Light-induced phosphorescence from thermographic phosphors was used to study the wall temperatures and heat fluxes from nearly one-dimensional flat premixed flames. The investigated flames were stoichiometric, lean and rich laminar methane/air flames with equivalence ratios of φ = 1, φ = 0.75 and φ = 1.25 at ambient pressure. The flames were burning in a stagnation point arrangement against a water-cooled plate. The central part of this plate was an alumina ceramic plate coated from both sides with chromium-doped alumina (ruby) and excited with a Nd:YAG laser or a green light-emitting diode (LED) array to measure the wall temperature from both sides and thus the heat flux rate from the flame. The outlet velocity of the gases was varied from 0.1 to 1.2 m/s. The burner to plate distance (H) ranged from 0.5 to 2 times the burner exit diameter ( d = 30 mm). The measured heat flux rates indicate the change of the flame stabilization mechanism from a burner stabilized to a stagnation plate stabilized flame. The results were compared to modeling results of a one-dimensional stagnation point flow, with a detailed reaction mechanism. In order to prove the model, gas phase temperatures were measured by OH-LIF for a stoichiometric stagnation point flame. It turns out that the flame stabilization mechanism and with it the heat fluxes change from low to high mass fluxes. This geometry may be well suited for further studies of the elementary flame wall interaction.

  6. Mathematical Analysis of the Historical Economic Growth with a Search for Takeoffs from Stagnation to Growth

    OpenAIRE

    Nielsen, Ron W

    2016-01-01

    Abstract. Data describing historical economic growth are analysed. Included in the analysis is the world and regional economic growth. The analysis demonstrates that historical economic growth had a natural tendency to follow hyperbolic distributions. Parameters describing hyperbolic distributions have been determined. A search for takeoffs from stagnation to growth produced negative results. This analysis throws a new light on the interpretation of the mechanism of the historical economic gr...

  7. A cross-country comparison of math achievement at teen age and cognitive performance 40 years later

    OpenAIRE

    Vegard Skirbekk; Valeria Bordone; Daniela Weber

    2014-01-01

    Background: Maintaining cognitive functioning through mid- to late-life is relevant for the individual and societal aim of active ageing. Evidence shows considerable stability in individual-level rank-ordering of cognitive functioning, but little attention has been given to cohort performance over the life cycle and macro-level factors that could affect it. Objective: The main goal of this paper is to address cross-national variation in mental performance from younger to older ages. Met...

  8. Attendance and Achievement in Medicine: Investigating the Impact of Attendance Policies on Academic Performance of Medical Students

    OpenAIRE

    Subramaniam, BS; Hande, S; Komattil, R

    2013-01-01

    Background: The attendance mandate for the medical course in Melaka Manipal Medical College, Manipal, India was increased from 75% to 90% based on the assumption that the mandatory increase will improve the students’ performance. Aims: To find out whether there is any correlation between class attendance and academic performance. Subjects and Methods: This was an institution based retrospective analytical study. Students who have completed Phase I (first two and a half years) of the MBBS cour...

  9. Final LDRD report : science-based solutions to achieve high-performance deep-UV laser diodes.

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Andrew M.; Miller, Mary A.; Crawford, Mary Hagerott; Alessi, Leonard J.; Smith, Michael L.; Henry, Tanya A.; Westlake, Karl R.; Cross, Karen Charlene; Allerman, Andrew Alan; Lee, Stephen Roger

    2011-12-01

    We present the results of a three year LDRD project that has focused on overcoming major materials roadblocks to achieving AlGaN-based deep-UV laser diodes. We describe our growth approach to achieving AlGaN templates with greater than ten times reduction of threading dislocations which resulted in greater than seven times enhancement of AlGaN quantum well photoluminescence and 15 times increase in electroluminescence from LED test structures. We describe the application of deep-level optical spectroscopy to AlGaN epilayers to quantify deep level energies and densities and further correlate defect properties with AlGaN luminescence efficiency. We further review our development of p-type short period superlattice structures as an approach to mitigate the high acceptor activation energies in AlGaN alloys. Finally, we describe our laser diode fabrication process, highlighting the development of highly vertical and smooth etched laser facets, as well as characterization of resulting laser heterostructures.

  10. An Initial Study of Relationships among the R&D Productivities of Patent Inventors in Patent, Academic Achievement and Professional Performances - An Example of Pixar Animation Studies

    Directory of Open Access Journals (Sweden)

    Mei-Yin Chen

    2004-09-01

    Full Text Available Patent information is seen to be a kind of information with the features of exactitude and trustfulness, and it can be used as an indicator to measure the capability of research and development in a company. This research initially explores the relationships among the R&D productivities of patent inventors in patents, academic achievements and professional performances in terms of a patent production aspect. Our research object is the Pixar Company, which had been devoted to 3D animation production for a long time and become one of the key players in the industry. This paper presents a study to discover the technical human resource in the company based on inventor analyses from patent information. Three problems were addressed as follows: (1 Pixar’s key inventors and their active periods, (2 the collaboration among these inventors, and (3 their academic achievements and professional performances and then examined their relationships among the patents, academic achievements and professional performances. In the study, we produced a graph to depict the collaboration of patent inventors when they cooperated to develop technologies and applied patents, and finally we integrated the graph with the search results from the ACM database and the IMDB databases to synthesize another graph to demonstrate the relationships among the productivities of key patent inventors in patents, academic achievements and professional performances. The findings show that in the digital content industry the performances of patent producing of technical talents principally come from the accumulation of their academic ability. When they applied the knowledge and the competence to the industry, they not only achieved remarkable success but also gained confirmation from international awards. Finally, the study also approved the potential and the feasibility of applying knowledge and techniques of bibliometrics to industrial analysis. [Article content in Chinese

  11. Effects of heat conduction and radical quenching on premixed stagnation flame stabilised by a wall

    Science.gov (United States)

    Zhang, Huangwei; Chen, Zheng

    2013-08-01

    The premixed stagnation flame stabilised by a wall is analysed theoretically considering thermally sensitive intermediate kinetics. We consider the limit case of infinitely large activation energy of the chain-branching reaction, in which the radical is produced infinitely fast once the cross-over temperature is reached. Under the assumptions of potential flow field and constant density, the correlation for flame position and stretch rate of the premixed stagnation flame is derived. Based on this correlation, the effects of heat conduction and radical quenching on the wall surface are examined. The wall temperature is shown to have great impact on flame bifurcation and extinction, especially when the flame is close to the wall. Different flame structures are observed for near-wall normal flame, weak flame, and critically quenched flame. The fuel and radical Lewis numbers are found to have opposite effects on the extinction stretch rate. Moreover, it is also demonstrated that only when the flame is close to the wall does the radical quenching strongly influence the flame bifurcation and extinction. The extinction stretch rate is shown to decrease with the amount of radical quenching for different fuel and radical Lewis numbers. Besides, the coupling between the wall heat conduction and radical quenching is found to greatly influence the bifurcation and extinction of the premixed stagnation flame.

  12. Stagnation temperature in a cold hypersonic flow produced by a light free piston compression facility

    Science.gov (United States)

    Widodo, Agung; Buttsworth, David

    2013-04-01

    Stagnation temperatures at the nozzle exit of the University of Southern Queensland hypersonic wind tunnel facility have been identified using an aspirating tube device with a 0.075 mm diameter k-type butt-welded thermocouple junction positioned at its inlet. Because of the finite thermal inertia of the thermocouple, a response time correction is introduced, and uncertainties in the response time correction are assessed and minimized by operating the aspirating device over a range of different initial temperatures. Pressure measurements within the barrel of the wind tunnel facility were used to estimate a theoretical upper bound on the flow stagnation temperature by assuming isentropic compression of the test gas. Results demonstrate that for the current operating conditions, the gas which is first delivered into the hypersonic nozzle has a stagnation temperature almost identical to the isentropic compression value of around 560 K, but a cooling effect is registered for the duration of the test flow which is about 200 ms. Thermodynamic simulations based on an unsteady energy balance model with turbulent heat transfer from the test gas within the barrel demonstrate a cooling effect of a similar magnitude to that indicated by the measured temperature variation, suggesting that strong mixing of the test gas occurs within the barrel during flow discharge through the hypersonic nozzle.

  13. La motivación de logro mejora el rendimiento académico (Achievement Motivation Improves Academic Performance

    Directory of Open Access Journals (Sweden)

    Jose Miguel Garcia-Ramirez

    2016-01-01

    Full Text Available A través de los proyectos de innovación docente las universidades mejoran y consolidan la calidad de la educación que ofrecen, tomando la creatividad y visibilidad como claves de la motivación por competencias y logro. Método: La investigación se realiza durante el curso académico 2013-14, a través del proyecto de innovación docente “ReiDoCrea” de la Universidad de Granada. Los participantes (N=62, M=22.7, SD=6.6, estudiantes de la Facultad de Ciencias del Trabajo, se adscribieron voluntariamente al Grupo Experimental (n=30 o al Grupo Control (n=32. El grupo experimental participó en el proyecto, mientras que el grupo control no participó; los instrumentos utilizados fueron dos pruebas objetivas (pre y post del programa de evaluación académica. Resultados: El análisis estadístico muestra que existen diferencias significativas entre los resultados obtenidos por el Grupo Experimental (M=83.6, SE=1.259, t(60=3.748, p<.05, d=.95 r=.43 y el Grupo Control (M=77.25, SE=1.14. Conclusiones: En la innovación docente, la motivación por competencias y de logro es clave para desarrollar el pensamiento creativo y mejorar el rendimiento académico. Abstract: Through teaching innovation projects universities improve and consolidate the quality of education they offer, taking creativity and visibility as the key to competence and achievement motivation. Method: The research study was conducted during the academic year 2013-14, through the teaching innovation project "ReiDoCrea" of the University of Granada. The participants (N=62, M=22.7, SD=6.6, students of the Faculty of Labour, voluntarily joined the Experimental Group (n=30 or the Control Group (n=32. The experimental group participated in the project, while the Control Group did not participate; the instruments used were two objective tests (pre and post, part of the academic program evaluation. Results: The statistical analysis shows that there are significant differences between the

  14. La motivación de logro mejora el rendimiento académico (Achievement Motivation Improves Academic Performance

    Directory of Open Access Journals (Sweden)

    Jose Miguel Garcia-Ramirez

    2016-01-01

    Full Text Available A través de los proyectos de innovación docente las universidades mejoran y consolidan la calidad de la educación que ofrecen, tomando la creatividad y visibilidad como claves de la motivación por competencias y logro. Método: La investigación se realiza durante el curso académico 2013-14, a través del proyecto de innovación docente “ReiDoCrea” de la Universidad de Granada. Los participantes (N=62, M=22.7, SD=6.6, estudiantes de la Facultad de Ciencias del Trabajo, se adscribieron voluntariamente al Grupo Experimental (n=30 o al Grupo Control (n=32. El grupo experimental participó en el proyecto, mientras que el grupo control no participó; los instrumentos utilizados fueron dos pruebas objetivas (pre y post del programa de evaluación académica. Resultados: El análisis estadístico muestra que existen diferencias significativas entre los resultados obtenidos por el Grupo Experimental (M=83.6, SE=1.259, t(60=3.748, p<.05, d=.95, r=.43 y el Grupo Control (M=77.25, SE=1.14. Conclusiones: En la innovación docente, la motivación por competencias y de logro es clave para desarrollar el pensamiento creativo y mejorar el rendimiento académico. Abstract: Through teaching innovation projects universities improve and consolidate the quality of education they offer, taking creativity and visibility as the key to competence and achievement motivation. Method: The research study was conducted during the academic year 2013-14, through the teaching innovation project "ReiDoCrea" of the University of Granada. The participants (N=62, M=22.7, SD=6.6, students of the Faculty of Labour, voluntarily joined the Experimental Group (n=30 or the Control Group (n=32. The experimental group participated in the project, while the Control Group did not participate; the instruments used were two objective tests (pre and post, part of the academic program evaluation. Results: The statistical analysis shows that there are significant differences between the

  15. The influence of the stagnation zone on the fluid dynamics at the nozzle exit of a confined and submerged impinging jet

    Science.gov (United States)

    Jeffers, Nicholas; Stafford, Jason; Conway, Ciaran; Punch, Jeff; Walsh, Edmond

    2016-02-01

    Low profile impinging jets provide a means to achieve high heat transfer coefficients while occupying a small quantity of space. Consequently, they are found in many engineering applications such as electronics cooling, annealing of metals, food processing, and others. This paper investigates the influence of the stagnation zone fluid dynamics on the nozzle exit flow condition of a low profile, submerged, and confined impinging water jet. The jet was geometrically constrained to a round, 16-mm diameter, square-edged nozzle at a jet exit to target surface spacing ( H/ D) that varied between 0.25 flow regimes is the main focus of this paper; however, laminar flow data are also presented between 1350 measurement facility was designed and commissioned to utilise particle image velocimetry in order to quantitatively measure the fluid dynamics both before and after the jet exits its nozzle. The velocity profiles are normalised with the mean velocity across the nozzle exit, and turbulence statistics are also presented. The primary objective of this paper is to present accurate flow profiles across the nozzle exit of an impinging jet confined to a low H/ D, with a view to guide the boundary conditions chosen for numerical simulations confined to similar constraints. The results revealed in this paper suggest that the fluid dynamics in the stagnation zone strongly influences the nozzle exit velocity profile at confinement heights between 0 0.5—where D is the inner diameter of the jet—in order to minimise modelling uncertainty.

  16. The Influence of Parenting Styles, Achievement Motivation, and Self-Efficacy on Academic Performance in College Students

    Science.gov (United States)

    Turner, Erlanger A.; Chandler, Megan; Heffer, Robert W.

    2009-01-01

    Parenting styles have consistently been shown to relate to various outcomes such as youth psychopathology, behavior problems, and academic performance. Building on the research in the parenting style literature, along with examining components of self-determination theory, the present study examined the relations among authoritative parenting…

  17. Supervised, Multivariate, Whole-brain Reduction Did Not Help to Achieve High Classification Performance in Schizophrenia Research

    Directory of Open Access Journals (Sweden)

    Eva Janousova

    2016-08-01

    Full Text Available We examined how penalized linear discriminant analysis with resampling, which is a supervised, multivariate, whole-brain reduction technique, can help schizophrenia diagnostics and research. In an experiment with magnetic resonance brain images of 52 first-episode schizophrenia patients and 52 healthy controls, this method allowed us to select brain areas relevant to schizophrenia, such as the left prefrontal cortex, the anterior cingulum, the right anterior insula, the thalamus and the hippocampus. Nevertheless, the classification performance based on such reduced data was not significantly better than the classification of data reduced by mass univariate selection using a t-test or unsupervised multivariate reduction using principal component analysis. Moreover, we found no important influence of the type of imaging features, namely local deformations or grey matter volumes, and the classification method, specifically linear discriminant analysis or linear support vector machines, on the classification results. However, we ascertained significant effect of a cross-validation setting on classification performance as classification results were overestimated even though the resampling was performed during the selection of brain imaging features. Therefore, it is critically important to perform cross-validation in all steps of the analysis (not only during classification in case there is no external validation set to avoid optimistically biasing the results of classification studies.

  18. Valuing Information in Complex Systems: An Integrated Analytical Approach to Achieve Optimal Performance in the Beer Distribution Game

    OpenAIRE

    Thompson, Kimberly M.; Badizadegan, Nima D.

    2015-01-01

    Even seemingly simple systems can produce complex dynamics, which leads management professionals to develop tools for training, monitoring, and improving performance. Management simulators provide useful insights about human behavior and interactions, while computational and informational decision support tools offer opportunities to reduce inconsistencies, errors, and non-optimal human choices, particularly for complex systems that involve multiple decision makers, uncertainty, variability, ...

  19. A Descriptive-Comparative Study of Teacher Performance Evaluation on Student Achievement in a Public School District

    Science.gov (United States)

    Christensen, William Howard

    2013-01-01

    In 2010, the federal government increased accountability expectations by placing more emphasis on monitoring teacher performance. Using a model that focuses on the New York State teacher evaluation system, that is comprised of a rubric for observation, local student assessment scores, and student state assessment scores, this…

  20. Ice mechanics, basal water and the stagnation of Kamb Ice Stream, Antarctica

    Science.gov (United States)

    Fried, M.; Hulbe, C. L.; Fahnestock, M. A.

    2012-12-01

    Several of the ice streams that move ice from the interior of the West Antarctic Ice Sheet (WAIS) to the Ross Ice Shelf are documented to stagnate and reactivate on multi-century time scales. Once such event may now be underway on the downstream ice plain of the Whillans Ice Stream (WIS), a stream that stopped and started between about 850 and 450 years ago. Kamb Ice Stream (KIS) ceased its rapid flow about 150 years ago in an event that appears to have initiated in the downstream reach of the ice stream. These switches from fast to slow and back again produce major changes in mass balance of the ice sheet and ice shelf system. Ice stream stagnation must in some way involve changes in the basal water that facilitates fast flow. Here, transients in ice thickness and surface slope, which together steer basal water, are examined in the context of the recent stagnation of KIS. Transients have both regional—changes in WIS flux and in Crary Ice Rise, for example—and local causes. A mechanical analysis of high-resolution surface elevation and ice velocity data sets on the now-active WIS is used as a proxy for past conditions on KIS and an ice flow model is used to place those local conditions in a regional context. We argue that thickness transients associated with stagnation of WIS required the KIS grounding line to retreat far upstream of its present location while reactivation of WIS led to regional thickening, grounding of floating ice, and advance of the KIS grounding line toward its present location. The present work examines the role of lateral margins near the grounding line, in particular the broad, flat, "Duckfoot" on the right lateral side of the KIS outlet and Lake Englehardt, which occupies the same postion at the outlet of WIS. Lake Englehardt diverts water away from the main trunk of the ice stream. In the past, the Duckfoot may have played a similar role and that diversion may have been associated with KIS stagnation. Overall, our aim is to understand

  1. THE ROLE OF STRATEGY IN ACHIEVING PERFORMANCE AND INTERNATIONAL RECOGNITION – THE CASE OF ROMANIAN ADVANCED RESEARCH UNIVERSITIES

    OpenAIRE

    Ruxandra CIULU; Olesia MIHAI

    2012-01-01

    The paper addresses the issue of strategy in higher education, applied to a group of top Romanian public universities. After reviewing the concepts of strategy (and its related sub-concepts), performance and internationalization, the authors briefly analyze the websites of the twelve Romanian universities included in the category ‘advanced research and education’. The study assesses the chances of Romanian universities to be included in the category of ‘top universities worldwide’ and conclu...

  2. New optical method for heat flux measurements in stagnation point laminar methane/air flames and hydrogen/methane/air flames using thermographic phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Elmnefi, Mohamed Salem

    2010-11-24

    In the present study, a new optical method was implemented to study the heat transfer from flat stagnation point flames which can be regarded as one-dimensional in the central part. Premixed methane-air flames and hydrogen-methane-air flames were investigated. The effects of burner-to-plate distance and the fresh gas mixture velocity on heat transfer were examined. Experiments were performed using light induced phosphorescence from thermographic phosphors to study the wall temperatures and heat fluxes of nearly one-dimensional flat premixed flames impinging upward normally on a horizontal water cooled circular flat plate. The investigated flames were stoichiometric, lean and rich laminar methane/air flames with different equivalence ratios of {phi} =1, {phi} = 0.75 and {phi} = 1.25 and stoichiometric laminar hydrogen/methane/air flames. Mixtures of air with 10, 25, 50 and 75 % hydrogen in methane (CH{sub 4}) as well as a pure hydrogen flames at ambient pressure were investigated. The central part of this plate was an alumina ceramic plate coated from both sides with chromium doped alumina (ruby) and excited with a Nd:YAG laser or a green light emitting diode (LED) array to measure the wall temperature from both sides and thus the heat flux rate from the flame. The outlet velocity of the gases was varied from 0.1 m/s to 1.2 m/s. The burner to plate distance ranged from 0.5 to 2 times the burner exit diameter (d = 30 mm).The accuracy of the method was evaluated. The measured heat flux indicate the change of the flame stabilization mechanism from a burner stabilized to a stagnation plate stabilized flame. The results were compared to modeling results of a one dimensional stagnation point flow, with a detailed reaction mechanism. In order to prove the model, also measured gas phase temperatures by OH LIF for a stoichiometric stagnation point flame were discussed. It turns out that the flame stabilization mechanism and with it the heat fluxes change from low to high

  3. Effects of heat exposure and 3% dehydration achieved via hot water immersion on repeated cycle sprint performance.

    Science.gov (United States)

    Kraft, Justin A; Green, James M; Bishop, Phillip A; Richardson, Mark T; Neggers, Yasmin H; Leeper, James D

    2011-03-01

    This study examined effects of heat exposure with and without dehydration on repeated anaerobic cycling. Males (n = 10) completed 3 trials: control (CT), water-bath heat exposure (∼39°C) to 3% dehydration (with fluid replacement) (HE), and similar heat exposure to 3% dehydration (DEHY). Hematocrit increased significantly from pre to postheat immersion in both HE and DEHY. Participants performed 6 × 15s cycle sprints (30s active recovery). Mean Power (MP) was significantly lower vs. CT (596 ± 66 W) for DEHY (569 ± 72 W), and the difference approached significance for HE (582 ± 76 W, p = 0.07). Peak Power (PP) was significantly lower vs. CT (900 ± 117 W) for HE (870 ± 128 W) and approached significance for DEHY (857 ± 145 W, p = 0.07). Postsprint ratings of perceived exertion was higher during DEHY (6.4 ± 2.0) and HE (6.3 ± 1.6) than CT (5.7 ± 2.1). Combined heat and dehydration impaired MP and PP (decrements greatest in later bouts) with HE performance intermediate to CT and DEHY.

  4. Control-value theory: using achievement emotions to improve understanding of motivation, learning, and performance in medical education: AMEE Guide No. 64.

    Science.gov (United States)

    Artino, Anthony R; Holmboe, Eric S; Durning, Steven J

    2012-01-01

    In this AMEE Guide, we consider the emergent theoretical and empirical work on human emotion and how this work can inform the theory, research, and practice of medical education. In the Guide, we define emotion, in general, and achievement emotions, more specifically. We describe one of the leading contemporary theories of achievement emotions, control-value theory (Pekrun 2006), and we distinguish between different types of achievement emotions, their proximal antecedents, and their consequences for motivation, learning, and performance. Next, we review the empirical support for control-value theory from non-medical fields and suggest several important implications for educational practice. In this section, we highlight the importance of designing learning environments that foster a high degree of control and value for students. Finally, we end with a discussion of the need for more research on achievement emotions in medical education, and we propose several key research questions we believe will facilitate our understanding of achievement emotions and their impact on important educational outcomes.

  5. The Development and Testing of Laboratory Performance Tasks for the Assessment of Achievement in High School Physics.

    Science.gov (United States)

    Boorman, Joan Marie

    The quest to stem "the rising tide of mediocrity" described in A Nation at Risk has prompted a myriad of changes in secondary science instruction. Appropriate assessments of these changes in curriculum are crucial to a meaningful evaluation of their effectiveness. Because the nature of many of the improvements has been to engage students in higher order thinking skills, simple paper and pencil tests are often inconclusive evaluation measures. Research has shown a more definitive assessment of a student's ability to apply higher order thinking skills is possible with tests of performance in problem-solving tasks in a science laboratory. The Physics Laboratory Skills Test (PLST) was developed as a prototype assessment instrument for evaluation of student ability to perform a range of process skills in the high school physics laboratory setting. The PLST included seven different items based on topics presented in a typical high school physics course. Each item constituted a separate laboratory performance test and was completed by individual students in a 40 minute class period. A sample of 219 physics students from rural, urban, public, and private schools in NY and PA were tested with the PLST in May 1990. Results of this study show that the PLST has usability, validity, and reliability as an assessment of basic skills (measuring and reporting) and higher order skills (planning and analysis). Participating teachers determined the PLST to be an appropriate and useful tool in evaluating individual student abilities. Content validity was established via evaluation by 'expert' high school physics teachers. The Pearson Correlation Coefficient was used to verify construct validity (r =.49) and inter-rater reliability (r =.81). The Cronbach Coefficient Alpha, which was used to determine internal consistency of each item, yielded strong positive results for the PLST. The outcomes of this study will be of particular interest to curriculum developers and classroom teachers

  6. Achieving enhanced DSSC performance by microwave plasma incorporation of carbon into TiO{sub 2} photoelectrodes

    Energy Technology Data Exchange (ETDEWEB)

    Dang, Binh H.Q.; MacElroy, Don [School of Chemical and Bioprocess Engineering, University College Dublin (Ireland); Dowling, Denis P., E-mail: denis.dowling@ucd.ie [School of Chemical and Bioprocess Engineering, University College Dublin (Ireland); School of Mechanical and Materials Engineering, University College Dublin (Ireland)

    2013-06-15

    The photoactivity of carbon-incorporated titanium dioxide (TiO{sub 2}) has been widely reported. This study involves a novel approach to the incorporation of carbon into TiO{sub 2} through the use of microwave plasma processing. The process involved thermally treating printed TiO{sub 2} nanoparticle coatings in a microwave-induced argon-oxygen plasma containing low concentrations of methane. The resulting deposited carbon layer was characterized using XRD, XPS, Raman, UV–vis, ellipsometry, and optical profilometry. It was found that the methane gas was dissociated in the microwave plasma into its carbon species, which were then deposited as a nm-thick layer onto the TiO{sub 2} coatings, most likely in the form of graphite. The photovoltaic performances of both the TiO{sub 2} and the carbon-incorporated TiO{sub 2} were assessed through J-V and IPCE measurements of the N719-sensitized solar cells using the titania as their photoanodes. Up to a 72% improvement in the maximum power density (P{sub d-max}) was observed for the carbon-incorporated TiO{sub 2} samples as compared to the TiO{sub 2}, onto which no carbon was added. This improvement was found to be mainly associated with an increase in the short-circuit current density (J{sub sc}), but independent from the open-circuit voltage (V{sub oc}), the filter factor (FF), and the level of dye adsorption. Possible contributory factors to the improved performance of the carbon-incorporated TiO{sub 2} were the enhanced electron conductivity and electron lifetime, both of which were elucidated through electrochemical impedance spectroscopy (EIS). When the surface layer was examined using XPS, the optimal carbon content on the TiO{sub 2} coating surface was found to be 8.4%, beyond which there was a reduction in the DSSC efficiency.

  7. Performance Achievement As The Impact Of Strategy Organizatonal Competence Strategy Execution And Competitive Advantage A Study On Private Polytechnics In West Java Indonesia

    Directory of Open Access Journals (Sweden)

    Bertha Musty

    2015-08-01

    Full Text Available ABSTRACT - The higher education environment has changed faster than the ability of higher education to respond the competition becomes more intense complex and dynamic making some polytechnics can thrive survive and others are stopping operations. This study was conducted to examine the profile of 29 polytechnics in West Java to achieve organizational performance. Research results show that polytechnic performance is affected by the quality of the execution and its competitive advantage which are determined by the precision and alignment strategies with organizational competence. The model findings of this study could be an analysis tool to solve the polytechnics survival problems how to face the intense competition and changing environment.

  8. The major upgrade of the MAGIC telescopes, Part II: The achieved physics performance using the Crab Nebula observations

    CERN Document Server

    Aleksic, J; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; Barcelo, M; Barrio, J A; Gonzalez, J Becerra; Bednarek, W; Bernardini, E; Biasuzzi, B; Biland, A; Bitossi, M; Blanch, O; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Cecchi, R; Colin, P; Colombo, E; Contreras, J L; Corti, D; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; Wilhelmi, E de Ona; Mendez, C Delgado; Dettlaff, A; Prester, D Dominis; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Fidalgo, D; Fink, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; Galindo, D; Lopez, R J Garcia; Garczarczyk, M; Terrats, D Garrido; Gaug, M; Giavitto, G; Godinovic, N; Munoz, A Gonzalez; Gozzini, S R; Haberer, W; Hadasch, D; Hanabata, Y; Hayashida, M; Herrera, J; Hildebrand, D; Hose, J; Hrupec, D; Idec, W; Illa, J M; Kadenius, V; Kellermann, H; Knoetig, M L; Kodani, K; Konno, Y; Krause, J; Kubo, H; Kushida, J; La Barbera, A; Lelas, D; Lemus, J L; Lewandowska, N; Lindfors, E; Lombardi, S; Longo, F; Lopez, M; Lopez-Coto, R; Lopez-Oramas, A; Lorca, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martinez, M; Mazin, D; Menzel, U; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Negrello, M; Neustroev, V; Niedzwiecki, A; Nilsson, K; Nishijima, K; Noda, K; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Persic, M; Poutanen, J; Moroni, P G Prada; Prandini, E; Puljak, I; Reinthal, R; Rhode, W; Ribo, M; Rico, J; Garcia, J Rodriguez; Rugamer, S; Saito, T; Saito, K; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schlammer, J; Schmidl, S; Schweizer, T; Shore, S N; Sillanpaa, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Stamerra, A; Steinbring, T; Storz, J; Strzys, M; Takalo, L; Takami, H; Tavecchio, F; Tejedor, L A; Temnikov, P; Terzic, T; Tescaro, D; Teshima, M; Thaele, J; Tibolla, O; Torres, D F; Toyama, T; Treves, A; Vogler, P; Wetteskind, H; Will, M; Zanin, R; IFAE,; UAB, Campus; Bellaterra, E-08193; Spain,; di Udine, Universita; Trieste, INFN; Udine, I-33100; Italy,; Astrophysics, INAF National Institute for; Rome, I-00136; di Siena, Universita; Pisa, INFN; Siena, I-53100; Institute, Rudjer Boskovic; Rijeka, University of; Split, University of; Zagreb, HR-10000; Croatia,; Physik, Max-Planck-Institut fur; Munchen, D-80805; Germany,; Complutense, Universidad; Madrid, E-28040; de Canarias, Inst de Astrofisica; La Laguna, E-38200; Tenerife,; Lodz, University of; Lodz, PL-90236; Poland,; Elektronen-Synchrotron, Deutsches; Zeuthen, D-15738; Zurich, ETH; Zurich, CH-8093; Switzerland,; Wurzburg, Universitat; Wurzburg, D-97074; Energeticas, Centro de Investigaciones; Tecnologicas, Medioambientales y; Sciences, Institute of Space; Barcelona, E-08193; di Padova, Universita; INFN,; Padova, I-35131; Dortmund, Technische Universitat; Dortmund, D-44221; Radiacions, Unitat de Fisica de les; de Fisica, Departament; CERES-IEEC,; de Barcelona, Universitat Autonoma; de Barcelona, Universitat; ICC,; IEEC-UB,; Barcelona, E-08028; Physics, Division of; Astronomy,; University, Kyoto; Japan,; Observatory, Tuorla; Turku, University of; Physics, Department of; Oulu, University of; Finland,; Research, Inst for Nucl; Energy, Nucl; Sofia, BG-1784; Bulgaria,; di Pisa, Universita; Pisa, I-56126; ICREA,; Insubria, Universita dell; Bicocca, INFN Milano; Como,; Como, I-22100; Observatory, European Gravitational; Macerata, I-56021 S Stefano a; Siena, INFN; at, now; :,; Center, NASA Goddard Space Flight; Greenbelt,; 20771, MD; USA,; Physics, Department of; Astronomy, Department of; Maryland, University of; Park, College; 20742, MD; de Lausanne, now at Ecole polytechnique federale; Lausanne,; Teilchenphysik, Now at Institut fur Astro- und; Innsbruck, Leopold-Franzens- Universitat; Innsbruck, A-6020; Austria,; deceased,; ESO, now at Finnish Centre for Astronomy with; Turku,; Division, now at Astrophysics Science; Centre, Bhabha Atomic Research; 400085, Mumbai; India,; INAF-Trieste, also at

    2014-01-01

    MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent a series of upgrades, involving the exchange of the MAGIC-I camera and its trigger system, as well as the upgrade of the readout system of both telescopes. We use observations of the Crab Nebula taken at low and medium zenith angles to assess the key performance parameters of the MAGIC stereo system. For low zenith observations the trigger threshold of the MAGIC telescopes is about 50GeV. The integral sensitivity for sources with Crab Nebula-like spectrum above 220GeV is (0.66+/-0.03)% of Crab Nebula flux in 50 h of observations. The angular resolution at those energies is < 0.07 degree, while the energy resolution is 16%. We also re-evaluate the effect of the systematic uncertainty on the data taken with the MAGIC telescopes after the upgrade. We estimate that the systematic uncertainties can be divided in following components: < 15% in energy scale...

  9. Off-centered stagnation point flow of a couple stress fluid towards a rotating disk.

    Science.gov (United States)

    Khan, Najeeb Alam; Riaz, Fatima

    2014-01-01

    An investigation has been made to study the off-centered stagnation flow of a couple stress fluid over a rotating disk. The model developed for the governing problem in the form of partial differential equations has been converted to ordinary differential equations with the use of suitable similarity transformation. The analytical approximation has been made with the most promising analytical approach, homotopy analysis method (HAM). The convergence region of the obtained solution is determined and plotted. The effects of couple stress and nondimensional parameters have been observed on the flows of couple stress fluid. Also comparison has been made with the Newtonian fluid as the special case of considered problem.

  10. MHD stagnation-point flow of an upper-convected Maxwell fluid over a stretching surface

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, T. [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Abbas, Z. [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan)], E-mail: za_qau@yahoo.com; Sajid, M. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad 44000 (Pakistan)

    2009-01-30

    The present analysis comprises the steady two-dimensional magnetohydrodynamic flow of an upper-convected Maxwell fluid near a stagnation-point over a stretching surface. The governing non-linear partial differential equation for the flow are reduced to an ordinary differential equation by using similarity transformations. The analytic solution of nonlinear system is constructed in the series form using Homotopy analysis method. Convergence of the obtained series is discussed explicitly. The effects of the sundry parameters on the velocity profile is shown through graphs. The values of skin-friction coefficient for different parameters is tabulated.

  11. Stagnation-Point Flow towards a Stretching Vertical Sheet with Slip Effects

    Directory of Open Access Journals (Sweden)

    Khairy Zaimi

    2016-04-01

    Full Text Available The effects of partial slip on stagnation-point flow and heat transfer due to a stretching vertical sheet is investigated. Using a similarity transformation, the governing partial differential equations are reduced into a system of nonlinear ordinary differential equations. The resulting equations are solved numerically using a shooting method. The effect of slip and buoyancy parameters on the velocity, temperature, skin friction coefficient and the local Nusselt number are graphically presented and discussed. It is found that dual solutions exist in a certain range of slip and buoyancy parameters. The skin friction coefficient decreases while the Nusselt number increases as the slip parameter increases.

  12. Impact of Entropy Generation on Stagnation-Point Flow of Sutterby Nanofluid: A Numerical Analysis

    Science.gov (United States)

    Azhar, Ehtsham; Iqbal, Z.; Maraj, E. N.

    2016-09-01

    The present article dicusses the computational analysis of entropy generation for the stagnation-point flow of Sutterby nanofluid over a linear stretching plate. The Sutterby fluid is chosen to study the effect for three major classes of non-Newtonian fluids, i.e. pseudoplastic, Newtonian, and dilatant. The effects of pertinent physical parameters are examined under the approximation of boundary layer. The system of coupled nonlinear partial differential equations is simplified by incorporating suitable similarity transformation into a system of non-linear-coupled ordinary differential equations. Entropy generation analysis is conducted numerically, and the results are displayed through graphs and tables. Significant findings are listed in the closing remarks.

  13. Heat transfer in MHD unsteady stagnation point flow with variable wall temperature

    Digital Repository Service at National Institute of Oceanography (India)

    Soundalgekar, V.M.; Murty, T.V.R.; Takhar, H.S.

    Indian J.pur~appl. Malh., 21 (4) : 384-389. April 1990 ,HEAT TRANSFER IN MHD UNSTEADY STAGNATION POINT FLOW WITH VARIABLE WALL TEMPERATURE V. M. SOUNDALGEKAR1. T. V. RAMANA MURTy2 AND B. S. TAKHAR3 131A/12 Brindavan Society, Thane 400 601 2/ndian... of free-stream oscillations cn the flow of an incompressible viscous fluid past a semi-infinite boay. The small amplituae pheno menon was studied. The unsteady motion of a semi-infinite plate in a viscous fluid was also studied by Cheng and ElJiott 2...

  14. Growth or stagnation in pre-industrial Britain? A revealed income growth approach

    DEFF Research Database (Denmark)

    Groth, Christian; Persson, Karl Gunnar

    The extent of growth in pre-industrial Europe in general and in Britain in particular has attracted intense scholarly focus. Growth or Malthusian stagnation? No consensus has evolved. Reconstructions of national income from 1300 and up to the Industrial Revolution come to opposing conclusions...... and so do econometric studies. Applying Engels’ law, we suggest a new approach in which income growth is revealed by changes in occupational structure. Data needed for this approach are less contested than the wage and output series used in the existing literature. We find that pre-industrial Britain...

  15. MHD Stagnation-Point Flow of Casson Fluid and Heat Transfer over a Stretching Sheet with Thermal Radiation

    Directory of Open Access Journals (Sweden)

    Krishnendu Bhattacharyya

    2013-01-01

    Full Text Available The two-dimensional magnetohydrodynamic (MHD stagnation-point flow of electrically conducting non-Newtonian Casson fluid and heat transfer towards a stretching sheet have been considered. The effect of thermal radiation is also investigated. Implementing similarity transformations, the governing momentum, and energy equations are transformed to self-similar nonlinear ODEs and numerical computations are performed to solve those. The investigation reveals many important aspects of flow and heat transfer. If velocity ratio parameter (B and magnetic parameter (M increase, then the velocity boundary layer thickness becomes thinner. On the other hand, for Casson fluid it is found that the velocity boundary layer thickness is larger compared to that of Newtonian fluid. The magnitude of wall skin-friction coefficient reduces with Casson parameter (β. The velocity ratio parameter, Casson parameter, and magnetic parameter also have major effects on temperature distribution. The heat transfer rate is enhanced with increasing values of velocity ratio parameter. The rate of heat transfer is enhanced with increasing magnetic parameter M for B > 1 and it decreases with M for B < 1. Moreover, the presence of thermal radiation reduces temperature and thermal boundary layer thickness.

  16. Impedance spectroscopy and structural properties of the perovskite-like Sn(Ba,Sr)O{sub 3} stagnate

    Energy Technology Data Exchange (ETDEWEB)

    Cuervo Farfan, J. [Grupo de Fisica de Nuevos Materiales, Departamento de Fisica, Universidad Nacional de Colombia, AA 5997, Bogota DC (Colombia); Ciencias Basicas, Universidad Manuela Beltran, Bogota DC (Colombia); Olaya, J.J. [Departamento de Ingenieria Mecanica y Mecatronica, Universidad Nacional de Colombia, Bogota DC (Colombia); Vera Lopez, E. [Grupo de Superficies, Electroquimica y Corrosion, Universidad Pedagogica y Tecnologica de Colombia, Tunja (Colombia); Landinez Tellez, D.A. [Grupo de Fisica de Nuevos Materiales, Departamento de Fisica, Universidad Nacional de Colombia, AA 5997, Bogota DC (Colombia); Roa-Rojas, J., E-mail: jroar@unal.edu.co [Grupo de Fisica de Nuevos Materiales, Departamento de Fisica, Universidad Nacional de Colombia, AA 5997, Bogota DC (Colombia)

    2012-08-15

    An exhaustive study of structural, electrical and transport properties on the perovskite stagnate Sn(Ba,Sr)O{sub 3} was performed. Samples of SnBa{sub 1-x}Sr{sub x}O{sub 3} with 0{<=}x{<=}1.00 were prepared by the solid state reaction method. The crystallographic structure was studied by X-ray diffraction experiments and Rietveld refinement using the GSAS code. Results reveal the material synthesized in a cubic structure (space group Pm3-bar m, no. 221) for 0{<=}x{<=}0.50 and in an orthorhombic (space group Pnma, no. 62) for x>0.50. The approximate grain size was found from experiments' Scanning Electron Microscopy. The electric response was studied by the Impedance Spectroscopy technique from 10.0 mHz up to 0,10 MHz. Electric polarization measurements for SnSrO{sub 3} and SnBaO{sub 3} were determined through curves of polarization as a function of applied electric field, which reveal the ferroelectric character of the material. From the saturation polarization the dielectric constants of materials were calculated.

  17. Mixed Convection Boundary Layer Stagnation-Point Flow of a Jeffery Fluid Past a Permeable Vertical Flat Plate

    Science.gov (United States)

    Rahman, Mohammad M.; Ioan, Pop

    2014-12-01

    This paper analyzes the combined effects of buoyancy force, mass flux, and variable surface temperature on the stagnation point flow and heat transfer due to a Jeffery fluid over a vertical surface. The governing nonlinear partial differential equations are transformed into a system of coupled nonlinear ordinary differential equations using similarity transformations and then solved numerically using the function bvp4c from computer algebra software Matlab. Numerical results are obtained for skin friction coefficient, Nusselt number as well as dimensionless velocity and temperature profiles for various values of the controlling parameters namely mixed convection parameter λ, mass flux parameter s, elastic parameter (Deborah number) γ, and the ratio of relaxation and retardation time parameter λ1. The results indicate that dual solutions exist in a certain range of the mixed convection and mass flux parameters. In order to establish the physically realizable of these solutions, a stability analysis has also been performed. The results indicate that mixed convection and mass flux significantly affects the nature of the solutions, skin friction, and Nusselt number of a Jeffery fluid.

  18. Performance-based tests versus behavioral ratings in the assessment of executive functioning in preschoolers: associations with ADHD symptoms and reading achievement.

    Directory of Open Access Journals (Sweden)

    Ana eMiranda

    2015-04-01

    Full Text Available The early assessment of the executive processes using ecologically valid instruments is essential for identifying deficits and planning actions to deal with possible adverse consequences. The present study has two different objectives. The first objective is to analyze the relationship between preschoolers’ performance on tests of Working Memory and Inhibition and parents’ and teachers’ ratings of these executive functions (EF using the Behavior Rating Inventory of Executive Function (BRIEF. The second objective consists of studying the predictive value of the different EF measures (performance-based test and rating scales on Inattention and Hyperactivity/Impulsivity behaviors and on indicators of word reading performance. The participants in the study were 209 children in the last year of preschool, their teachers and their families. Performance-based tests of Working Memory and Inhibition were administered, as well as word reading measures (accuracy and speed. The parents and teachers filled out rating scales of the EF and typical behaviors of ADHD symptomatology. Moderate correlation values were found between the different EF assessments procedures, although the results varied depending on the different domains. Metacognition index from the BRIEF presented stronger correlations with verbal working memory tests than with inhibition tests. Both the rating scales and the performance-based tests were significant predictors of Inattention and Hyperactivity/Impulsivity behaviors and the reading achievement measures. However, the BRIEF explained a greater percentage of variance in the case of the ADHD symptomatology, while the performance-based tests explained reading achievement to a greater degree. The implications of the findings for research and clinical practice are discussed.

  19. Compositional mantle layering revealed by slab stagnation at ~1000-km depth.

    Science.gov (United States)

    Ballmer, Maxim D; Schmerr, Nicholas C; Nakagawa, Takashi; Ritsema, Jeroen

    2015-12-01

    Improved constraints on lower-mantle composition are fundamental to understand the accretion, differentiation, and thermochemical evolution of our planet. Cosmochemical arguments indicate that lower-mantle rocks may be enriched in Si relative to upper-mantle pyrolite, whereas seismic tomography images suggest whole-mantle convection and hence appear to imply efficient mantle mixing. This study reconciles cosmochemical and geophysical constraints using the stagnation of some slab segments at ~1000-km depth as the key observation. Through numerical modeling of subduction, we show that lower-mantle enrichment in intrinsically dense basaltic lithologies can render slabs neutrally buoyant in the uppermost lower mantle. Slab stagnation (at depths of ~660 and ~1000 km) and unimpeded slab sinking to great depths can coexist if the basalt fraction is ~8% higher in the lower mantle than in the upper mantle, equivalent to a lower-mantle Mg/Si of ~1.18. Global-scale geodynamic models demonstrate that such a moderate compositional gradient across the mantle can persist can in the presence of whole-mantle convection. PMID:26824060

  20. Study of magnetic fields and current in the Z pinch at stagnation

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, V. V.; Anderson, A. A.; Astanovitskiy, A. L.; Nalajala, V.; Dmitriev, O. [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States); Papp, D. [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States); ELI-ALPS, ELI-Hu Nkft., H-6720 Szeged (Hungary)

    2015-09-15

    The structure of magnetic fields in wire-array Z pinches at stagnation was studied using a Faraday rotation diagnostic at the wavelength of 266 nm. The electron plasma density and the Faraday rotation angle in plasma were calculated from images of the three-channel polarimeter. The magnetic field was reconstructed with Abel transform, and the current was estimated using a simple model. Several shots with wire-array Z pinches at 0.5–1.5 MA were analyzed. The strength of the magnetic field measured in plasma of the stagnated pinch was in the range of 1–2 MG. The magnetic field and current profile in plasma near the neck on the pinch were reconstructed, and the size of the current-carrying plasma was estimated. It was found that current flowed in the large-size trailing plasma near the dense neck. Measurements of the magnetic field near the bulge on the pinch also showed current in trailing plasma. A distribution of current in the large-size trailing plasma can prevent the formation of multi-MG fields in the Z pinch.

  1. Microfluidic-based single cell trapping using a combination of stagnation point flow and physical barrier

    Institute of Scientific and Technical Information of China (English)

    Miao Yu; Zongzheng Chen; Cheng Xiang; Bo Liu; Handi Xie; Kairong Qin

    2016-01-01

    Single cell trapping in vitro by microfluidic device is an emerging approach for the study of the rela-tionship between single cells and their dynamic biochemical microenvironments. In this paper, a hydrodynamic-based microfluidic device for single cell trapping is designed using a combination of stagnation point flow and physical barrier. The microfluidic device overcomes the weakness of the tra-ditional ones, which have been only based upon either stag-nation point flows or physical barriers, and can conveniently load dynamic biochemical signals to the trapped cell. In addi-tion, it can connect with a programmable syringe pump and a microscope to constitute an integrated experimental system. It is experimentally verified that the microfluidic system can trap single cells in vitro even under flow disturbance and con-veniently load biochemical signals to the trapped cell. The designed micro-device would provide a simple yet effective experimental platform for further study of the interactions between single cells and their microenvironments.

  2. Detection of flow separation and stagnation points using artificial hair sensors

    Science.gov (United States)

    Phillips, D. M.; Ray, C. W.; Hagen, B. J.; Su, W.; Baur, J. W.; Reich, G. W.

    2015-11-01

    Recent interest in fly-by-feel approaches for aircraft control has motivated the development of novel sensors for use in aerial systems. Artificial hair sensors (AHSs) are one type of device that promise to fill a unique niche in the sensory suite for aerial systems. In this work, we investigate the capability of an AHS based on structural glass fibers to directly identify flow stagnation and separation points on a cylindrical domain in a steady flow. The glass fibers are functionalized with a radially aligned carbon nanotube (CNT) forest and elicit a piezoresistive response as the CNT forest impinges on electrodes in a micropore when the hair is deflected due to viscous drag forces. Particle image velocimetry is used to measure the flow field allowing for the resulting moment and force acting on the hair to be correlated with the electrical response. It is demonstrated that the AHS provides estimates for the locations of both the stagnation and separation in steady flow. From this, a simulation of a heading estimation is presented to demonstrate a potential application for hair sensors. These results motivate the construction of large arrays of hair sensors for imaging and resolving flow structures in real time.

  3. Study of magnetic fields and current in the Z pinch at stagnation

    International Nuclear Information System (INIS)

    The structure of magnetic fields in wire-array Z pinches at stagnation was studied using a Faraday rotation diagnostic at the wavelength of 266 nm. The electron plasma density and the Faraday rotation angle in plasma were calculated from images of the three-channel polarimeter. The magnetic field was reconstructed with Abel transform, and the current was estimated using a simple model. Several shots with wire-array Z pinches at 0.5–1.5 MA were analyzed. The strength of the magnetic field measured in plasma of the stagnated pinch was in the range of 1–2 MG. The magnetic field and current profile in plasma near the neck on the pinch were reconstructed, and the size of the current-carrying plasma was estimated. It was found that current flowed in the large-size trailing plasma near the dense neck. Measurements of the magnetic field near the bulge on the pinch also showed current in trailing plasma. A distribution of current in the large-size trailing plasma can prevent the formation of multi-MG fields in the Z pinch

  4. The Role of Lithium Conditioning in Achieving High Performance, Long Pulse H-mode Discharges in the NSTX and EAST Devices

    Energy Technology Data Exchange (ETDEWEB)

    Maingi, Rajesh [PPPL; Mansfield, D. K. [PPPL; Gong, X. Z. [IPPCAS; Sun, Z. [IPPCAS; Bell, M. G. [PPPL

    2014-10-01

    In this paper, the role of lithium wall conditioning on the achievement of high performance, long pulse discharges in the National Spherical Torus Experiment (NSTX) and the Experimental Advanced Superconducting Tokamak (EAST) is documented. Common observations include recycling reduction and elimination of ELMs. In NSTX, lithium conditioning typically resulted in ELM-free operation with impurity accumulation, which was ameliorated e.g. with pulsed 3D fields to trigger controlled ELMs. Active lithium conditioning in EAST discharges has overcome this problem, producing an ELM-free Hmode with controlled density and impurities.

  5. Effect of the choice of stagnation density in data-fitted first- and second-order traffic models

    CERN Document Server

    Fan, Shimao

    2013-01-01

    For a class of data-fitted macroscopic traffic models, the influence of the choice of the stagnation density on the model accuracy is investigated. This work builds on an established framework of data-fitted first-order Lighthill-Whitham-Richards (LWR) models and their second-order Aw-Rascle-Zhang (ARZ) generalizations. These models are systematically fitted to historic fundamental diagram data, and then their predictive accuracy is quantified via a version of the three-detector problem test, considering vehicle trajectory data and single-loop sensor data. The key outcome of this study is that with commonly suggested stagnation densities of 120 vehicles/km/lane and above, information travels backwards too slowly. It is then demonstrated that the reduction of the stagnation density to 90-100 vehicles/km/lane addresses this problem and results in a significant improvement of the predictive accuracy of the considered models.

  6. The Classroom Performance System (CPS): Effects on student participation, attendance, and achievement in multicultural anatomy and physiology classes at South Texas College

    Science.gov (United States)

    Termos, Mohamad Hani

    2011-12-01

    The Classroom Performance System (CPS) is an instructional technology tool that increases student performance and addresses different learning styles. Instructional technologies are used to promote active learning; however, student embarrassment issue in a multicultural setting is not addressed. This study assessed the effect of the CPS on student participation, attendance, and achievement in multicultural college-level anatomy and physiology classes at South Texas College, where the first spoken language is not English. Quantitative method and quasi-experimental design were employed and comparative statistic methods and pre-post tests were used to collect the data. Participants were college students and sections of study were selected by convenient sampling. Participation was 100% during most of the lectures held and participation rate did not strike above 68% in control group. Attendance was significantly higher in CPS sections than the control group as shown by t-tests. Experimental sections had a higher increase in the pre-post test scores and student averages on lecture exams increased at a higher rate as compared to the control group. Therefore, the CPS increased student participation, attendance, and achievement in multicultural anatomy and physiology classes. The CPS can be studied in other settings where the first spoken language is English or in other programs, such as special education programs. Additionally, other variables can be studied and other methodologies can be employed.

  7. 抑郁症肝郁气滞证及肝郁脾虚证证候标准的研究%Studies on standards for syndromes of Hepatic Qi Stagnation and Hepatic Stagnation causing Splenic Deficiency for depression

    Institute of Scientific and Technical Information of China (English)

    陈珍贵; 陈泽奇; 胡随瑜; 张海男; 张宏耕

    2003-01-01

    目的探讨抑郁症肝郁气滞证、肝郁脾虚证的证候辨证标准.方法选择抑郁症临床流行病学调查肝郁气滞证588例,肝郁脾虚证487例,共1 075例,对75项证候指标进行频数分析、χ2检验等统计学处理,并建立判别方程.根据统计分析,采取主证辨证法确定两证的证候标准.结果肝郁气滞证的证候标准为:情绪抑郁、悲观厌世、善叹息、烦躁、脉弦,5项中具备3项(情绪抑郁必备),记分在4分以上者,即可诊断.肝郁脾虚证的证候标准为:情绪抑郁、悲观厌世、善叹息、倦怠乏力、纳差、形体消瘦、脉细,7项中具备4项,即肝郁两项(情绪抑郁必备),脾虚两项者,总记分在6分以上者,即可诊断.结论情绪抑郁、善叹息等5项为肝郁气滞证的证候标准,情绪抑郁、倦怠乏力、纳差等7项为肝郁脾虚证的证候标准.%Objective:To explore the standard of syndrome differentiation of the Hepatic Qi Stagnation and Hepatic Stagnation causing Splenic Deficiency for depression. Methods:588 cases with syndromes of the Hepatic Qi Stagnation and 487 cases with syndromes of the Hepatic Stagnation causing Splenic Deficiency, 1075 cases in sum,were from clinical epidemiological survery. 75 indexes were analyzed by frequency analysis and Chi-squared test. Then discriminant equations were established.According to the results of statistic analysis, by the differentiation of primary symptoms, the standard of syndrome with the Hepatic Qi Stagnation and syndrome with Hepatic Stagnation causing Splenic Deficiency for depression were developed. Results:The standard of syndrome with the Hepatic Qi Stagnation was the five symptoms including emotion depression, pessimism, sigh, dysphoria and stringy pulse.When more than three symptoms occur(emotion depression is necessary ) and the total scores are more than 4 ,the differentiation can be established. The standard of differentiation of syndrome with Hepatic Stagnation causing

  8. Academic Momentum at University/College: Exploring the Roles of Prior Learning, Life Experience, and Ongoing Performance in Academic Achievement across Time

    Science.gov (United States)

    Martin, Andrew J.; Wilson, Rachel; Liem, Gregory Arief D.; Ginns, Paul

    2014-01-01

    In the context of "academic momentum," a longitudinal study of university students (N = 904) showed high school achievement and ongoing university achievement predicted subsequent achievement through university. However, the impact of high school achievement diminished, while additive effects of ongoing university achievement continued.…

  9. MHD stagnation point flow toward a linearly-stretching thermally-insulated sheet with induced magnetic field

    CERN Document Server

    El-Mistikawy, Tarek M A

    2016-01-01

    The equations governing the magnetohydrodynamic stagnation point flow toward a non-conducting, thermally insulated, nonporous, linearly stretching sheet are cast in a self similar form. Consistent boundary conditions on the velocity, magnetic field and temperature are invoked. The flow problem involves three parameters- the magnetic Prandtl number, the magnetic interaction number, and the ratio of the stretching rate to the strength of the stagnation point flow. The energy equation includes viscous dissipation and Joule heating, and introduces the Prandtl number as a fourth parameter. Numerical solutions are obtained and sample results are presented.

  10. Investigations of subterranean microorganisms and their importance for performance assessment of radioactive waste disposal. Results and conclusions achieved during the period 1995 to 1997

    International Nuclear Information System (INIS)

    In 1987, microbiology became a part of the Swedish scientific program for the safe disposal of high level nuclear waste (HLW). The goal of the microbiology sub-program is to understand how subterranean microorganisms will interact with the performance of a future HLW repository. The Swedish research program on subterranean microbiology has mainly been performed at two sites in granitic rock aquifers at depths ranging from 70 m down to 1240 m; the Stripa research mine in the middle of Sweden and the Aespoe hard rock laboratory (HRL) situated on the south eastern coast of Sweden. Some work has also been performed in co-operation with other national or international research groups in Sweden, Canada and at the natural analogue sites in Oklo in Gabon and Maqarin in Jordan. The most recent report in the SKB technical report series on microbiology and performance assessment, SKB-TR--95-10, gave the state of the art regarding microorganisms and their importance for performance assessment. That report is recommended as a source of knowledge about basic microbiology, microbial ecology of subterranean environments and the nuclear waste disposal concept in a microbiological perspective. The present report summarises results and conclusions achieved during the period 1995 to 1997 and is a continuation of SKB TR 95-10. The report is structured as summary which explains and analyses the obtained results and conclusions in a performance assessment perspective. The scientific basis for the summary is an enclosed series of eleven papers of which eight have gone through an international peer review process for publication in international scientific journals and reports and papers published earlier

  11. Investigations of subterranean microorganisms and their importance for performance assessment of radioactive waste disposal. Results and conclusions achieved during the period 1995 to 1997

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, K. [Goeteborg Univ. (Sweden). Dept. of General and Marine Microbiology

    1997-11-01

    In 1987, microbiology became a part of the Swedish scientific program for the safe disposal of high level nuclear waste (HLW). The goal of the microbiology sub-program is to understand how subterranean microorganisms will interact with the performance of a future HLW repository. The Swedish research program on subterranean microbiology has mainly been performed at two sites in granitic rock aquifers at depths ranging from 70 m down to 1240 m; the Stripa research mine in the middle of Sweden and the Aespoe hard rock laboratory (HRL) situated on the south eastern coast of Sweden. Some work has also been performed in co-operation with other national or international research groups in Sweden, Canada and at the natural analogue sites in Oklo in Gabon and Maqarin in Jordan. The most recent report in the SKB technical report series on microbiology and performance assessment, SKB-TR--95-10, gave the state of the art regarding microorganisms and their importance for performance assessment. That report is recommended as a source of knowledge about basic microbiology, microbial ecology of subterranean environments and the nuclear waste disposal concept in a microbiological perspective. The present report summarises results and conclusions achieved during the period 1995 to 1997 and is a continuation of SKB TR 95-10. The report is structured as summary which explains and analyses the obtained results and conclusions in a performance assessment perspective. The scientific basis for the summary is an enclosed series of eleven papers of which eight have gone through an international peer review process for publication in international scientific journals and reports and papers published earlier. 413 refs, 56 figs, 39 tabs.

  12. Assessment of In-Core Damage for Feeder Stagnation Break in CANDU

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jong Yeob; Park, Joo Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-05-15

    A feeder break is a single channel accident while the other channels remain intact in the CANDU core. For some ranges of feeder break size, a flow in the channel can become stagnate due to a force balance between the upstream and the downstream ends. In the extreme, this can lead to a rapid fuel heat up and fuel damage, and the failure of a fuel channel. This break scenario is called a feeder stagnation break. Following the feeder stagnation break, the fuel and pressure tube in the affected channel heat up quickly. The channel fails due to overheating and the channel contents begin to discharge into the moderator. The discharge is composed of steam, some hydrogen produced by possible metal-water reaction, and solid fuel elements of fuel fragments with molten material. The severity of the transient is primarily determined by the amount of molten material discharged into the moderator, and by the interaction between the molten material and the moderator, which determines the rate of energy release. After a channel rupture (pressure tube and calandria tube) some SOR (Shut-Off Rod) guide tubes, which are located in the vicinity of the break in the core, may be damaged. If the damage to the guide tube is substantial, some SORs may not be able to descend into the moderator, and therefore, not contribute to the shut down of the reactor. The increase in system reactivity, due to factors such as poison dilution from discharging coolant and void formation, may challenge the reactivity worth of the available undamaged SORs. Therefore, an analysis of the reactivity worth of the partially impaired SDS 1 (Shut-Down System 1) is required to determine that it can compensate for the increase in reactivity and shut down the reactor. In this study, the hydrodynamic transient, due to the dispersed molten material and the discharged steam, was calculated following the feeder stagnation break. The timing of the channel failure and the mass of the molten material were provided from the

  13. Momentum and Heat Transfer in MHD Axisymmetric Stagnation-Point Flow over a Shrinking Sheet

    Directory of Open Access Journals (Sweden)

    T. R. Mahapatra

    2013-01-01

    Full Text Available In this paper we present a mathematical analysis for the magneto hydrodynamic (MHD axi-symmetric stagnation-point flow and heat transfer over a shrinking sheet which shrinks axi-symmetrically in its own plane. The governing partial differential equations along with the boundary conditions are first cast into a dimensionless form and then these equations are solved numerically by shooting technique. Thermal conductivity is assumed to vary linearly with the temperature. Temperature profiles are obtained for two different types of heating process namely (i the sheet with prescribed surface temperature (PST and (ii the sheet with prescribed surface heat flux (PHF. The effects of various physical parameters on the flow and heat transfer characteristics are presented graphically and discussed.

  14. Hydromagnetic Stagnation-Point Flow towards a Radially Stretching Convectively Heated Disk

    Directory of Open Access Journals (Sweden)

    S. Shateyi

    2013-01-01

    Full Text Available The steady stagnation-point flow and heat transfer of an electrically conducted incompressible viscous fluid are extended to the case where the disk surface is convectively heated and radially stretching. The fluid is subjected to an external uniform magnetic field perpendicular to the plane of the disk. The governing momentum and energy balance equations give rise to nonlinear boundary value problem. Using a spectral relaxation method with a Chebyshev spectral collocation method, the numerical solutions are obtained over the entire range of the physical parameters. Emphasis has been laid to study the effects of viscous dissipation and Joule heating on the thermal boundary layer. Pertinent results on the effects of various thermophysical parameters on the velocity and temperature fields as well as local skin friction and local Nusselt number are discussed in detail and shown graphically and/or in tabular form.

  15. Melting heat transfer in boundary layer stagnation-point flow towards a stretching/shrinking sheet

    Energy Technology Data Exchange (ETDEWEB)

    Bachok, Norfifah [Department of Mathematics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Ishak, Anuar [School of Mathematical Sciences, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Pop, Ioan, E-mail: popm.ioan@yahoo.co.u [Faculty of Mathematics, University of Cluj, CP 253 (Romania)

    2010-09-06

    An analysis is carried out to study the steady two-dimensional stagnation-point flow and heat transfer from a warm, laminar liquid flow to a melting stretching/shrinking sheet. The governing partial differential equations are converted into ordinary differential equations by similarity transformation, before being solved numerically using the Runge-Kutta-Fehlberg method. Results for the skin friction coefficient, local Nusselt number, velocity profiles as well as temperature profiles are presented for different values of the governing parameters. Effects of the melting parameter, stretching/shrinking parameter and Prandtl number on the flow and heat transfer characteristics are thoroughly examined. Different from a stretching sheet, it is found that the solutions for a shrinking sheet are non-unique.

  16. Melting heat transfer in stagnation point flow of carbon nanotubes towards variable thickness surface

    Directory of Open Access Journals (Sweden)

    T. Hayat

    2016-01-01

    Full Text Available This work concentrates on the mathematical modeling for stagnation point flow of nanofluids over an impermeable stretching sheet with variable thickness. Carbon nanotubes [single-wall carbon nanotubes (SWCNTs and multi-wall carbon nanotubes (MWCNTs] as the nanoparticles are utilized. Water and kerosene oil are taken as the base fluids. Heat transfer through melting effect is discussed. Transformation procedure is adapted to obtain the non-linear ordinary differential equations from the fundamental laws of mass, linear momentum and energy. The optimal values of convergence control parameters and corresponding individual and total residual errors for SWCNTs and MWCNTs are computed by means of homotopy analysis method (HAM based BVPh 2.0. Characteristics of different involved parameters on the velocity, temperature, skin friction coefficient and Nusselt number are discussed. Higher velocity profile is observed for wall thickness parameter in case of water carbon nanotubes when compared with the kerosene oil carbon nanotubes.

  17. Interaction of Magnetic Field and Nonlinear Convection in the Stagnation Point Flow over a Shrinking Sheet

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar

    2016-01-01

    Full Text Available The steady two-dimensional boundary layer stagnation point flow due to a shrinking sheet is analyzed. The combined effects of magnetic field and nonlinear convection are taken into account. The governing equations for the flow are modeled and then simplified using the similarity transformation and boundary layer approach. The numerical solution of the reduced equations is obtained by the second-order finite difference scheme also known as Keller box method. The influence of the pertinent parameters of the problem on velocity and temperature profiles, skin friction, and sheet temperature gradient are presented through the graphs and tables and discussed. The magnetic field and nonlinear convection parameters significantly enhance the solution range.

  18. Dual Solutions in Unsteady Stagnation-Point Flow over a Shrinking Sheet

    Institute of Scientific and Technical Information of China (English)

    Krishnendu Bhattacharyya

    2011-01-01

    @@ An analysis is made to study the dual nature of solution of unsteady stagnation-point Sow due to a shrinking sheet.Using similarity transformations, the governing boundary layer equations are transformed into the self-similar nonlinear ordinary differential equations.The transformed equations are solved numerically using a very efficient shooting method.The study reveals the conditions of existence, uniqueness and non-existence of unsteady similarity solution.The dual solutions for velocity distribution exist for certain values of velocity ratio parameter (c/a), and the increment in the unsteadiness parameter A increases the range of cla where solution exists.Also,with increasing A, the skin friction coefficient increases for the first solution and decreases for the second.

  19. Steady Stagnation Point Flow and Heat Transfer Over a Shrinking Sheet with Induced Magnetic Field

    Directory of Open Access Journals (Sweden)

    Aniruddha Sinha

    2014-01-01

    Full Text Available The problem of the steady magnetohydrodynamic (MHD stagnation-point flow of an incompressible, viscous and electrically conducting fluid over a shrinking sheet is studied. The effects of an induced magnetic field and thermal radiation are taken into account. Velocity and thermal slip conditions have also been incorporated in the study. The nonlinear partial differential equations are transformed into ordinary differential equations via the similarity transformation. The transformed boundary layer equations are solved numerically using Newton’s linearization method. Computational results for the variation in velocity, temperature, skin-friction co-efficient and Nusselt number are presented graphically and in tabular form. Study reveals that the surface velocity gradient and heat transfer are enhanced by decreasing magnetic parameter.

  20. Radiation Effects on MHD Stagnation-Point Flow in a Nanofluid

    Directory of Open Access Journals (Sweden)

    Mohammad Eftekhari Yazdi

    2013-05-01

    Full Text Available In this study, the two-dimensional Magnetohydrodynamic (MHD boundary layer of stagnation-point flow in a nanofluid in the presence of thermal radiation is investigated. Using a similarity transform, the Navier-Stokes equations are reduced to a set of nonlinear ordinary differential equations. The similarity equations are solved numerically for three types of nanoparticles, namely copper (Cu, alumina (Al2O3 and titania (TiO2 in water as the base fluid. The skin-friction coefficient and Nusselt number as well as the velocity and temperature profiles for some values of the governing parameters are presented graphically and discussed. Effects of the nanoparticle volume fraction on the flow and heat transfer characteristics are thoroughly examined.

  1. Series solutions of stagnation slip flow and heat transfer by the homotopy analysis method

    Institute of Scientific and Technical Information of China (English)

    R.N.MOHAPATRA; K.VAJRAVELU

    2009-01-01

    An analytical approximation for the similarity solutions of the two-and three-dimensional stagnation slip flow and heat transfer is obtained by using the homotopy analysis method. This method is a series expansion method, but it is different from the perturbation technique, because it is independent of small physical parameters at all. Instead, it is based on a continuous mapping in topology so that it is applicable for not only weakly but also strongly nonlinear flow phenomena. Convergent [m,m] homotopy Padé approximants are obtained and compared with the numerical results and the asymptotic approximations. It is found that the homotopy Padé approximants agree well with the numerical results. The effects of the slip length and the thermal slip constant β on the heat transfer characteristics are investigated and discussed.

  2. Series solutions of stagnation slip flow and heat transfer by the homotopy analysis method

    Institute of Scientific and Technical Information of China (English)

    CHENG Jun; LIAO ShiJun; R. N. MOHAPATRA; K. VAJRAVELU

    2009-01-01

    An analytical approximation for the similarity solutions of the two- and three-dimensional stagnation slip flow and heat transfer is obtained by using the homotopy analysis method. This method is a series expansion method, but it is different from the perturbation technique, because it is independent of small physical parameters at all. Instead, it is based on a continuous mapping in topology so that it is applicable for not only weakly but also strongly nonlinear flow phenomena. Convergent [m,m] homotopy Pade approximants are obtained and compared with the numerical results and the numerical results. The effects of the slip length and the thermal slip constant β on the heat transfer characteristics are investigated and discussed.

  3. Manipulating flow separation: sensitivity of stagnation points, separatrix angles and recirculation area to steady actuation

    CERN Document Server

    Boujo, Edouard

    2014-01-01

    A variational technique is used to derive analytical expressions for the sensitivity of several geometric indicators of flow separation to steady actuation. Considering the boundary layer flow above a wall-mounted bump, the six following representative quantities are considered: the locations of the separation point and reattachment point connected by the separatrix, the separation angles at these stagnation points, the backflow area and the recirculation area. For each geometric quantity, linear sensitivity analysis allows us to identify regions which are the most sensitive to volume forcing and wall blowing/suction. Validations against full non-linear Navier-Stokes calculations show excellent agreement for small-amplitude control for all considered indicators. With very resemblant sensitivity maps, the reattachment point, the backflow and recirculation areas are seen to be easily manipulated. In contrast, the upstream separation point and the separatrix angles are seen to remain extremely robust with respec...

  4. Axisymmetric Stagnation-Point Flow with a General Slip Boundary Condition over a Lubricated Surface

    Institute of Scientific and Technical Information of China (English)

    M. Sajid; K. Mahmood; Z. Abbas

    2012-01-01

    We investigate the axisymmetric stagnation-point flow of a viscous fluid over a lubricated surface by imposing a generalized slip condition at the fluid-fluid interface.The power law non-Newtonian fluid is considered as a lubricant.The lubrication layer is thin and assumed to have a variable thickness.The transformed nonlinear ordinary differential equation governing the flow is linearized using quasilinearization.The method of superposition is adopted to convert the boundary value problem into an initial value problem and the solution is obtained numerically by using the fourth-order RungeKutta method.The results are discussed to see the influence of pertinent parameters.The limiting cases of Navier and no-slip boundary conditions are obtained as the special cases and found to be in excellent agreement with the existing results in the literature.%We investigate the axisymmetric stagnation-point flow of a viscous fluid over a lubricated surface by imposing a generalized slip condition at the fluid-fluid interface. The power law non-Newtonian fluid is considered as a lubricant. The lubrication layer is thin and assumed to have a variable thickness. The transformed nonlinear ordinary differential equation governing the flow is linearized using quasilinearization. The method of superposition is adopted to convert the boundary value problem into an initial value problem and the solution is obtained numerically by using the fourth-order Runge Kutta method. The results arc discussed to see the influence of pertinent parameters. The limiting cases of Navier and no-slip boundary conditions are obtained as the special cases and found to be in excellent agreement with the existing results in the literature.

  5. The stagnation of the Mexican male life expectancy in the first decade of the 21st century

    DEFF Research Database (Denmark)

    Canudas-Romo, Vladimir; García-Guerrero, Víctor Manuel; Echarri-Cánovas, Carlos Javier

    2015-01-01

    OBJECTIVES: In the first decade of the 21st century, the Mexican life expectancy changed from a long trend of increase to stagnation. These changes concur with an increase in deaths by homicides that the country experienced in that decade, and an obesity epidemic that had developed over the last ...

  6. Investigation on the Behavior of Austenite and Ferrite Phases at Stagnation Region in the Turning of Duplex Stainless Steel Alloys

    Science.gov (United States)

    Nomani, J.; Pramanik, A.; Hilditch, T.; Littlefair, G.

    2016-06-01

    This paper investigates the deformation mechanisms and plastic behavior of austenite and ferrite phases in duplex stainless steel alloys 2205 and 2507 under chip formation from a machine turning operation. SEM images and EBSD phase mapping of frozen chip root samples detected a build-up of ferrite bands in the stagnation region, and between 65 and 85 pct, more ferrite was identified in the stagnation region compared to austenite. SEM images detected micro-cracks developing in the ferrite phase, indicating ferritic build-up in the stagnation region as a potential triggering mechanism to the formation of built-up edge, as transgranular micro-cracks found in the stagnation region are similar to micro-cracks initiating built-up edge formation. Higher plasticity of austenite due to softening under high strain is seen responsible for the ferrite build-up. Flow lines indicate that austenite is plastically deforming at a greater rate into the chip, while ferrite shows to partition most of the strain during deformation. The loss of annealing twins and activation of multiple slip planes triggered at high strain may explain the highly plastic behavior shown by austenite.

  7. Achieving Standardization

    DEFF Research Database (Denmark)

    Henningsson, Stefan

    2016-01-01

    competitive, national customs and regional economic organizations are seeking to establish a standardized solution for digital reporting of customs data. However, standardization has proven hard to achieve in the socio-technical e-Customs solution. In this chapter, the authors identify and describe what has...... to be harmonized in order for a global company to perceive e-Customs as standardized. In doing so, they contribute an explanation of the challenges associated with using a standardization mechanism for harmonizing socio-technical information systems....

  8. Achieving Standardization

    DEFF Research Database (Denmark)

    Henningsson, Stefan

    2014-01-01

    competitive, national customs and regional economic organizations are seeking to establish a standardized solution for digital reporting of customs data. However, standardization has proven hard to achieve in the socio-technical e-Customs solution. In this chapter, the authors identify and describe what has...... to be harmonized in order for a global company to perceive e-Customs as standardized. In doing so, they contribute an explanation of the challenges associated with using a standardization mechanism for harmonizing socio-technical information systems....

  9. The impact of nursing students' chemistry learning performance assessment in Taiwan: competitive versus non-competitive student team achievement division approaches

    Science.gov (United States)

    Wang, Kai-Ping

    2012-07-01

    Purpose: The purpose of this study was to determine the effectiveness of competitive Student Team Achievement Division (STAD), non-competitive STAD, and traditional learning on chemistry learning and learning perceptions. Sample, design and methods: By adopting the STAD approach, this study examined 144 nursing students at a five-year junior college in northern Taiwan during the first semester (totaling 18 weeks) of the 2008 academic year. Results: The findings reveal that both a heterogeneous group with external pressure (involving competitive STAD) and a friendship group with affective pressure (involving traditional learning) enhance group cohesion and assist students' meaningful learning; the heterogeneous group without extra pressure (involving non-competitive STAD), by contrast, fails because of apathy and lassitude. Moreover, learning effectiveness will obviously predominate until the learning strategy continues for a long period or at least one semester. Conclusions: This study revealed that the learning performance level of the competitive STAD group is significantly different from that of the non-competitive STAD group; and the learning performance level of the traditional group is significantly different from that of the non-competitive STAD group. Both the competitive STAD group and traditional group of medium ability students are significantly different from the non-competitive STAD group. Low-ability students from the competitive STAD group are significantly different from those of the non-competitive STAD, though no significant differences were found in learning perception. However, both a lack of friendship and a lack of ability in using algorithms may affect students' chemistry learning. Furthermore, gender imbalance, educational culture, and group emotions are factors that may influence student learning performance. Further study should focus on the use of grouping, improve responsibility in group discussion, and investigate group interaction

  10. Effects of Gyejibongnyeong-hwan on dysmenorrhea caused by blood stagnation: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Park Jeong-Su

    2012-01-01

    Full Text Available Abstract Background Gyejibongnyeong-hwan (GJBNH is one of the most popular Korean medicine formulas for menstrual pain of dysmenorrhea. The concept of blood stagnation in Korean medicine is considered the main factor of causing abdominal pain, or cramps, during menstrual periods. To treat the symptoms, GJBNH is used to fluidify the stagnated blood and induce the blood flow to be smooth, reducing pain as the result. The purpose of this trial is to identify the efficacy of GJBNH in dysmenorrhea caused by blood stagnation. Methods This study is a multi-centre, randomised, double-blind, controlled trial with two parallel arms: the group taking GJBNH and the group taking placebo. 100 patients (women from age 18 to 35 will be enrolled to the trial. Through randomization 50 patients will be in experiment arm, and the other 50 patients will be in control arm. At the second visit (baseline, all participants who were already screened that they fulfil both the inclusion and the exclusion criteria will be randomised into two groups. Each group will take the intervention three times per day during two menstrual cycles. After the treatment for two cycles, each patient will be followed up during their 3rd, 4th and 5th menstrual cycles. From the screening (Visit 1 through the second follow-up (Visit 6 the entire process will take 25 weeks. Discussion This trial will provide evidence for the effectiveness of GJBNH in treating periodical pain due to dysmenorrhea that is caused by blood stagnation. The primary outcome between the two groups will be measured by changes in the Visual Analogue Score (VAS of pain. The secondary outcome will be measured by the Blood Stagnation Scale, the Short-form McGill questionnaire and the COX menstrual symptom scale. Analysis of covariance (ANCOVA and repeated measured ANOVA will be used to analyze the data analysis. Trial registration Current Controlled Trials: ISRCTN30426947

  11. Is yield increase sufficient to achieve food security in China?

    Science.gov (United States)

    Wei, Xing; Zhang, Zhao; Shi, Peijun; Wang, Pin; Chen, Yi; Song, Xiao; Tao, Fulu

    2015-01-01

    Increasing demand for food, driven by unprecedented population growth and increasing consumption, will keep challenging food security in China. Although cereal yields have substantially improved during the last three decades, whether it will keep thriving to meet the increasing demand is not known yet. Thus, an integrated analysis on the trends of crop yield and cultivated area is essential to better understand current state of food security in China, especially on county scale. So far, yield stagnation has extensively dominated the main cereal-growing areas across China. Rice yield is facing the most severe stagnation that 53.9% counties tracked in the study have stagnated significantly, followed by maize (42.4%) and wheat (41.9%). As another important element for production sustainability, but often neglected is the planted area patterns. It has been further demonstrated that the loss in productive arable land for rice and wheat have dramatically increased the pressure on achieving food security. Not only a great deal of the planted areas have stagnated since 1980, but also collapsed. 48.4% and 54.4% of rice- and wheat-growing counties have lost their cropland areas to varying degrees. Besides, 27.6% and 35.8% of them have retrograded below the level of the 1980s. The combined influence (both loss in yield and area) has determined the crop sustainable production in China to be pessimistic for rice and wheat, and consequently no surprise to find that more than half of counties rank a lower level of production sustainability. Therefore, given the potential yield increase in wheat and maize, as well as substantial area loss of rice and wheat, the possible targeted adaptation measures for both yield and cropping area is required at county scale. Moreover, policies on food trade, alongside advocation of low calorie diets, reducing food loss and waste can help to enhance food security. PMID:25680193

  12. Is yield increase sufficient to achieve food security in China?

    Directory of Open Access Journals (Sweden)

    Xing Wei

    Full Text Available Increasing demand for food, driven by unprecedented population growth and increasing consumption, will keep challenging food security in China. Although cereal yields have substantially improved during the last three decades, whether it will keep thriving to meet the increasing demand is not known yet. Thus, an integrated analysis on the trends of crop yield and cultivated area is essential to better understand current state of food security in China, especially on county scale. So far, yield stagnation has extensively dominated the main cereal-growing areas across China. Rice yield is facing the most severe stagnation that 53.9% counties tracked in the study have stagnated significantly, followed by maize (42.4% and wheat (41.9%. As another important element for production sustainability, but often neglected is the planted area patterns. It has been further demonstrated that the loss in productive arable land for rice and wheat have dramatically increased the pressure on achieving food security. Not only a great deal of the planted areas have stagnated since 1980, but also collapsed. 48.4% and 54.4% of rice- and wheat-growing counties have lost their cropland areas to varying degrees. Besides, 27.6% and 35.8% of them have retrograded below the level of the 1980s. The combined influence (both loss in yield and area has determined the crop sustainable production in China to be pessimistic for rice and wheat, and consequently no surprise to find that more than half of counties rank a lower level of production sustainability. Therefore, given the potential yield increase in wheat and maize, as well as substantial area loss of rice and wheat, the possible targeted adaptation measures for both yield and cropping area is required at county scale. Moreover, policies on food trade, alongside advocation of low calorie diets, reducing food loss and waste can help to enhance food security.

  13. Is yield increase sufficient to achieve food security in China?

    Science.gov (United States)

    Wei, Xing; Zhang, Zhao; Shi, Peijun; Wang, Pin; Chen, Yi; Song, Xiao; Tao, Fulu

    2015-01-01

    Increasing demand for food, driven by unprecedented population growth and increasing consumption, will keep challenging food security in China. Although cereal yields have substantially improved during the last three decades, whether it will keep thriving to meet the increasing demand is not known yet. Thus, an integrated analysis on the trends of crop yield and cultivated area is essential to better understand current state of food security in China, especially on county scale. So far, yield stagnation has extensively dominated the main cereal-growing areas across China. Rice yield is facing the most severe stagnation that 53.9% counties tracked in the study have stagnated significantly, followed by maize (42.4%) and wheat (41.9%). As another important element for production sustainability, but often neglected is the planted area patterns. It has been further demonstrated that the loss in productive arable land for rice and wheat have dramatically increased the pressure on achieving food security. Not only a great deal of the planted areas have stagnated since 1980, but also collapsed. 48.4% and 54.4% of rice- and wheat-growing counties have lost their cropland areas to varying degrees. Besides, 27.6% and 35.8% of them have retrograded below the level of the 1980s. The combined influence (both loss in yield and area) has determined the crop sustainable production in China to be pessimistic for rice and wheat, and consequently no surprise to find that more than half of counties rank a lower level of production sustainability. Therefore, given the potential yield increase in wheat and maize, as well as substantial area loss of rice and wheat, the possible targeted adaptation measures for both yield and cropping area is required at county scale. Moreover, policies on food trade, alongside advocation of low calorie diets, reducing food loss and waste can help to enhance food security.

  14. The new research centre of the Brazilian Petroleum Company in Rio de Janeiro, Brazil: The achievements in the thermal performance of air-conditioned buildings in the tropics

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Rafael; Marcondes, Monica Pereira; De Benedetto, Gisele S.; Goncalves, Joana Carla Soares; Duarte, Denise Helena Silva; Ramos, Jose Ovidio [Laboratorio de Conforto Ambiental e Eficiencia Energetica (LABAUT), Departamento de Tecnologia da Arquitetura (AUT), Faculdade de Arquitetura e Urbanismo, Universidade de Sao Paulo (FAUUSP), Sao Paulo, Brasil, Rua do Lago, 876, Cidade Universitaria, 05508-900 Sao Paulo, SP (Brazil)

    2008-07-01

    The study on the thermal performance of the air-conditioned buildings of the new research centre of the Brazilian Petroleum Company, in the tropical climate of Rio de Janeiro, was part of a bigger research and consultancy project involving environmental issues. The architectural design was the subject of a national competition in 2004, encompassing over 100,000 m{sup 2}. According to the design brief, out of the 10 buildings of the new research centre, 7 have to be either completely or partially air-conditioned, due to specific occupation requirements. The challenge for better thermal performance was related to systems' energy efficiency, to the introduction of natural ventilation and to the notion of adaptive comfort, which were verified with the support of thermal dynamic simulations. At the early stages of the assessments, the potential for natural ventilation in the working spaces considering the mixed-mode strategy achieved 30% of occupation hours. However, the development of the design project led to fully air-conditioned working spaces, due to users' references regarding the conventional culture of the office environment. Nevertheless, the overall architectural approach in accordance to the climatic conditions still showed a contribution to the buildings' energy efficiency. (author)

  15. An analysis of factors correlated with the achievement of the goal standard for the science portion of the Connecticut Academic Performance Test

    Science.gov (United States)

    Kmetz, Barbara Fotta

    2001-07-01

    This study sought to identify factors that could be used to predict the success of students on the science portion of the grade ten Connecticut Academic Performance Test (CAPT). While the Connecticut State Department of Education measures student achievement in mathematics, reading and writing in grades 4, 6, and 8, science is assessed only in the grade ten CAPT. Since the CAPT science test does not identify specific areas in need of improvement, it is not possible to determine causes for low test scores. To address this, the study investigated the predictive values of the grade eight Mastery Tests in mathematics and reading, the student ability scores of the Otis-Lennon School Ability Index, and grades in prior science courses. The research sample consisted of five hundred and twenty-five students, member of the graduating classes of 2000 and 2001 in a large suburban high school. Students in the study had participated in the district testing program and their scores for the grade seven Otis-Lennon School Ability Test (OLSAT), the grade eight Connecticut Mastery Tests (CMT) and the grade ten Connecticut Academic Performance Tests (CAPT) were available for analysis. This study investigated correlations between student achievement on the CMT and the science subtest of the CAPT, between OLSAT scores and the CAPT science scores, and between grades in ninth grade science and CAPT science scores. Scores were disaggregated by gender and by course level. Hypotheses 1, 2, 3 and 4 investigated the Pearson Product Moment Correlations of the OLSAT, CMT and course grades with scores on the science portion of the CAPT. Hypothesis 5 compared the scores of male and female students, using the t-test of independent sample means. Calculations showed moderate correlations for hypotheses 1--4, and the hypotheses were accepted. Hypothesis 5 was accepted for one class and rejected for the other. On the whole, female students received higher course grades and lower standardized test

  16. Achieving New Source Performance Standards (NSPS) Emission Standards Through Integration of Low-NOx Burners with an Optimization Plan for Boiler Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Wayne Penrod

    2006-12-31

    The objective of this project was to demonstrate the use of an Integrated Combustion Optimization System to achieve NO{sub X} emission levels in the range of 0.15 to 0.22 lb/MMBtu while simultaneously enabling increased power output. The project plan consisted of the integration of low-NO{sub X} burners and advanced overfire air technology with various process measurement and control devices on the Holcomb Station Unit 1 boiler. The plan included the use of sophisticated neural networks or other artificial intelligence technologies and complex software to optimize several operating parameters, including NO{sub X} emissions, boiler efficiency, and CO emissions. The program was set up in three phases. In Phase I, the boiler was equipped with sensors that can be used to monitor furnace conditions and coal flow to permit improvements in boiler operation. In Phase II, the boiler was equipped with burner modifications designed to reduce NO{sub X} emissions and automated coal flow dampers to permit on-line fuel balancing. In Phase III, the boiler was to be equipped with an overfire air system to permit deep reductions in NO{sub X} emissions. Integration of the overfire air system with the improvements made in Phases I and II would permit optimization of boiler performance, output, and emissions. This report summarizes the overall results from Phases I and II of the project. A significant amount of data was collected from the combustion sensors, coal flow monitoring equipment, and other existing boiler instrumentation to monitor performance of the burner modifications and the coal flow balancing equipment.

  17. A planning model for expansion and stagnation of higher education in Iran.

    Directory of Open Access Journals (Sweden)

    Aeen Mohammadi

    2014-10-01

    Full Text Available Iran universities of medical sciences have experienced a period of expansion in past decades. Now previous concerns are alleviated, and the former quantity-based policy has given a way to a more quality-seeking attitude. In this study, we developed a planning model for expansion and stagnation of higher education in Iranian universities of medical sciences based on workforce requirements of the country and capabilities of the universities. The plan provided an objectively documented base for the authorities to decide on developmental limits of universities. We devised guidelines for justifying existing programs within universities, assigning new undergraduate and postgraduate programs to universities, voluntary request of universities to cancel a program, and their request to offer new programs for the first time in the country, based on three factors: university educational status, each university-program educational status and the nation's need for each discipline. Related councils of the Ministry of Health and Medical Education legitimately approved the plan and guidelines. In this article, we introduced the methodology of developing the plan, described it and its related guidelines and discussed challenges and limitations we encountered in design and application phases.

  18. Rapid trench initiated recrystallization and stagnation in narrow Cu interconnect lines

    Science.gov (United States)

    O'Brien, Brendan B.; Rizzolo, Michael; Prestowitz, Luke C.; Dunn, Kathleen A.

    2015-10-01

    Understanding and ultimately controlling the self-annealing of Cu in narrow interconnect lines has remained a top priority in order to continue down-scaling of back-end of the line interconnects. Recently, it was hypothesized that a bottom-up microstructural transformation process in narrow interconnect features competes with the surface-initiated overburden transformation. Here, a set of transmission electron microscopy images which captures the grain coarsening process in 48 nm lines in a time resolved manner is presented, supporting such a process. Grain size measurements taken from these images have demonstrated that the Cu microstructural transformation in 48 nm interconnect lines stagnates after only 1.5 h at room temperature. This stubborn metastable structure remains stagnant, even after aggressive elevated temperature anneals, suggesting that a limited internal energy source such as dislocation content is driving the transformation. As indicated by the extremely low defect density found in 48 nm trenches, a rapid recrystallization process driven by annihilation of defects in the trenches appears to give way to a metastable microstructure in the trenches.

  19. Large amplitude oscillation of a boiling bubble growing at a wall in stagnation flow

    International Nuclear Information System (INIS)

    A boiling bubble is created on an artificial site that is part of a bubble generator that is mounted at the center of a pipe. Downflow of water impinges on the bubble generator and creates a stagnation flow above the artificial cavity. Stable axisymmetric elongation in the direction away from the wall and multiple shape oscillation cycles are observed. The time of growth and attachment is typically of the order of 250 ms. Amongst the length scales that characterize the bubble shape is the radius of curvature of the upper part of the bubble, R. The period of oscillation, T, is strongly dependent on time, as is R. The parameters C and m in the defining equation T = C Rm √(ρL/σ) have been determined by fitting to data of more than 100 bubbles. For each operating condition, the same values of C and m have been found. The value of m is 1.49 ± 0.02, which is explained from the continuous growth of the bubble and from the relation to the period of oscillation of a free bubble deforming in the fundamental mode corresponding to the third Legendre Polynomial. For the latter, R is the radius of the volume-equivalent sphere, R0, and C is √12, while for attached boiling bubbles C is found to amount 1.9√12. The difference is easily explained from the continuous growth, difference in definition, finite amplitude oscillation and proximity of the wall. (author)

  20. Effects of Thermal Noise on the Transitional Dynamics of an Inextensible Elastic Filament in Stagnation Flow

    Science.gov (United States)

    Deng, Mingge; Grinberg, Leopold; Caswell, Bruce

    2015-01-01

    We investigate the dynamics of a single inextensible elastic filament subject to anisotropic friction in a viscous stagnation-point flow, by employing both a continuum model represented by Langevin type stochastic partial differential equations (SPDEs) and a Dissipative Particle Dynamics (DPD) method. Unlike previous works1, the filament is free to rotate and the tension along the filament is determined by the local inextensible constraint. The kinematics of the filament is recorded and studied with normal modes analysis. The results show that the filament displays an instability induced by negative tension, which is analogous to Euler buckling of a beam. Symmetry breaking of normal modes dynamics and stretch-coil transitions are observed above the threshold of the buckling instability point. Furthermore, both temporal and spatial noise are amplified resulting from the interaction of thermal fluctuations and nonlinear filament dynamics. Specifically, the spatial noise is amplified with even normal modes being excited due to symmetry breaking, while the temporal noise is amplified with increasing time correlation length and variance. PMID:26023834

  1. Oxidation of iridium coating on rhenium coated graphite at elevated temperature in stagnated air

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yongle; Bai, Shuxin, E-mail: NUDT_MSE_501@163.com; Zhang, Hong; Ye, Yicong

    2015-02-15

    Highlights: • Continuous and dense Ir coatings were prepared on graphite by electrodepostion. • The purification of the as-prepared Ir coating was higher than about 99.98%. • The Ir/Re/C specimen kept integrity without significant failures after oxidation. • The average oxidation rate of the Ir coating was about 0.219 mg/(cm{sup 2} min). • Penetrating holes at gains boundaries resulted in the failure of the Ir coating. - Abstract: Continuous and dense iridium coatings were prepared on the rhenium coated graphite specimens by electrodeposition. The iridium/rhenium coated graphite (Ir/Re/C) specimens were oxidized at elevated temperatures in stagnated air for 3600 s. The purification of the as-prepared Ir coating was higher than about 99.98% with the main impurity elements Si, Al, Fe and Ru. After oxidation, the Ir/Re/C specimens kept integrity without significant failures and the average oxidation rate was about 0.219 mg/(cm{sup 2} min). Pores were found at the grain boundaries and concentrated to penetrating holes with the growth of Ir grains, which resulted in disastrous failures of the Ir coating.

  2. Effect of wall structure on pebble stagnation behavior in pebble bed reactor

    International Nuclear Information System (INIS)

    Highlights: • DEM study of wall structure role in preventing near wall crystallization is carried out. • Suggestions on pebble’s kinematic parameters and wall structure design are provided. • Triangle is better than arc and sawtooth shapes for wall structure design. • Wall structure size should be close to the scale of pebble diameter. • Suitable intervals can prevent crystallization without significantly increasing the flow resistance. - Abstract: Crystallization of pebbles in pebble bed is a crucial problem in high temperature gas-cooled pebble-bed reactors. This phenomenon usually happens along the internal surface and leads to a large number of stagnated pebbles, which poses a threat to reactor safety. In real reactor engineering, wall structures have been utilized to avoid this problem. This article verifies the crystallization phenomenon through DEM (discrete element method) simulation, and explains how wall structures work in preventing crystallization. Moreover, several kinematic parameters have been adopted to evaluate wall structures with different shapes, sizes and intervals. Detailed information shows the impact of wall structure on flow field in pebble bed. Lastly, the preferred characteristics of an effective wall structure are suggested for reactor engineering

  3. Rapid trench initiated recrystallization and stagnation in narrow Cu interconnect lines

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Brendan B.; Rizzolo, Michael; Prestowitz, Luke C.; Dunn, Kathleen A., E-mail: kdunn1@sunypoly.edu [Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, New York 12203 (United States)

    2015-10-26

    Understanding and ultimately controlling the self-annealing of Cu in narrow interconnect lines has remained a top priority in order to continue down-scaling of back-end of the line interconnects. Recently, it was hypothesized that a bottom-up microstructural transformation process in narrow interconnect features competes with the surface-initiated overburden transformation. Here, a set of transmission electron microscopy images which captures the grain coarsening process in 48 nm lines in a time resolved manner is presented, supporting such a process. Grain size measurements taken from these images have demonstrated that the Cu microstructural transformation in 48 nm interconnect lines stagnates after only 1.5 h at room temperature. This stubborn metastable structure remains stagnant, even after aggressive elevated temperature anneals, suggesting that a limited internal energy source such as dislocation content is driving the transformation. As indicated by the extremely low defect density found in 48 nm trenches, a rapid recrystallization process driven by annihilation of defects in the trenches appears to give way to a metastable microstructure in the trenches.

  4. Proton imaging of hohlraum plasma stagnation in inertial-confinement-fusion experiments

    International Nuclear Information System (INIS)

    Proton radiography of the spatial structure and temporal evolution of plasma blowing off from a hohlraum wall reveals how the fill gas compresses the wall blow-off, inhibits plasma jet formation and impedes plasma stagnation in the hohlraum interior. The roles of spontaneously generated electric and magnetic fields in hohlraum dynamics and capsule implosions are demonstrated. The heat flux is shown to rapidly convect the magnetic field due to the Nernst effect, which is shown to be ∼10 times faster than convection by the plasma fluid from expanded wall blow-off (vN ∼ 10v). This leads to inhibition of heat transfer from the gas region in the laser beam paths to the surrounding cold gas, resulting in a local plasma temperature increase. The experiments show that interpenetration of the two materials (gas and wall) occurs due to the classical Rayleigh–Taylor instability as the lighter, decelerating ionized fill gas pushes against the heavier, expanding gold wall blow-off. This experiment provides physics insight into the effects of fill gas on x-ray-driven implosions, and would impact the ongoing ignition experiments at the National Ignition Facility. (paper)

  5. Radiation Effect on MHD Stagnation-Point Flow of a Nanofluid over an Exponentially Stretching Sheet

    Directory of Open Access Journals (Sweden)

    Imran ANWAR

    2014-07-01

    Full Text Available This paper theoretically investigates the radiation effect on magnetohydrodynamics (MHD stagnation-point flow of a nanofluid over an exponentially stretching sheet under the assumptions of a small magnetic Reynolds number. The sheet is stretched with an exponential velocity in the presence of a non-uniform magnetic field B applied in a transverse direction normal to the flow. By using the modified Bernoulli's equation, a highly nonlinear nanofluid problem is modeled for an electrically conducting nanofluid. The momentum, thermal and concentration boundary layer thicknesses are intensified for the incorporated flow parameters such as Brownian motion parameter Nb, thermophoresis parameter Nt, Prandtl number Pr, Lewis number Le, Hartmann number Mexp and velocity ratio parameter ε. Also by an appropriate similarity transformation, the system of nonlinear partial differential equations is reduced to ordinary differential equations. These equations subjected to the boundary conditions are solved numerically using the Keller-box method. Numerical results are plotted and discussed for pertinent flow parameters. A comparison with existing results in the literature is also provided.doi:10.14456/WJST.2014.11

  6. A uniformly valid series solution to the unsteady stagnation-point flow towards an impulsively stretching surface

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The paper studies the problem of the unsteady two-dimensional stagnation-point flow of an incompressible viscous fluid over a flat deformable sheet. The flow is started impulsively from rest and the sheet is suddenly stretched in its own plane with a velocity proportional to the distance from the stagnation point. An analytical series solution is obtained by means of the homotopy analysis method (HAM). Also, the homotopy-Pade′ technique is employed. An explicit formula for the local friction coefficient is provided. The present formula, different from the perturbation solution, is accurate and uniformly valid for all dimensionless time in the whole spatial region and for all possible values of physical parameter λ, defined as the ratio of the potential flow velocity to the sheet sudden stretching velocity. Numerical tests are done to verify the present formula for its validity and accuracy.

  7. System and method for confining an object to a region of fluid flow having a stagnation point

    Science.gov (United States)

    Schroeder, Charles M. (Inventor); Shaqfeh, Eric S. G. (Inventor); Babcock, Hazen P. (Inventor); Chu, Steven (Inventor)

    2006-01-01

    A device for confining an object to a region proximate to a fluid flow stagnation point includes one or more inlets for carrying the fluid into the region, one or more outlets for carrying the fluid out of the region, and a controller, in fluidic communication with the inlets and outlets, for adjusting the motion of the fluid to produce a stagnation point in the region, thereby confining the object to the region. Applications include, for example, prolonged observation of the object, manipulation of the object, etc. The device optionally may employ a feedback control mechanism, a sensing apparatus (e.g., for imaging), and a storage medium for storing, and a computer for analyzing and manipulating, data acquired from observing the object. The invention further provides methods of using such a device and system in a number of fields, including biology, chemistry, physics, material science, and medical science.

  8. Two-Dimensional Stagnation-Point Velocity-Slip Flow and Heat Transfer over Porous Stretching Sheet

    Directory of Open Access Journals (Sweden)

    FEROZ AHMED SOOMRO

    2016-10-01

    Full Text Available Present paper investigates 2D (Two-Dimensional stagnation-point velocity-slip flow over porous stretching sheet. The governing non-linear PDEs (Partial Differential Equations are non-dimensionlized by using the similarity transformation technique that results into coupled non-linear ODEs (Ordinary Differential Equations. Such ODEs are then solved by using shooting technique with fourth-order Runge-Kutta method. Since the behavior of boundary layer stagnation-point flow depends on the rate of cooling and stretching. Therefore, the main objective of this paper is to analyze the effects of different working parameters on shear stress, heat transfer, velocity and temperature of fluid. The results revealed that the velocity-slip has significant effect on the fluid flow as well as on the heat transfer. The numerical results are also compared with existing work for no-slip condition and found to have good agreement with improved asymptotic behavior.

  9. Nonlinear convection stagnation point heat transfer and MHD fluid flow in porous medium towards a permeable shrinking sheet

    CERN Document Server

    Kumar, Rakesh

    2015-01-01

    This investigation deals with the analysis of stagnation point heat transfer and corresponding flow features of hydromagnetic viscous incompressible fluid over a vertical shrinking sheet. The considered sheet is assumed to be permeable and subject to addition of stagnation point to control the generated vorticity in the boundary layer. The sheet is placed on the right side of the fluid saturated porous medium which is having permeability of specified form. Nonlinear convection waves in the flow field are realized due to the envisaged nonlinear relation between density and temperature. The equations governing the nonlinear convection boundary layer flow are modeled and simplified using similarity transformations. The economized equations are solved for numerical solutions by employing the implicit finite difference scheme also known as Keller-box method. The influence of the associated parameters of the problem on velocity and temperature distributions, skin friction and rate of heat transfer are presented thr...

  10. Study the Micropolar Fluid Flow near the Stagnation on a Vertical Plate with Prescribed Wall Heat Flux

    Directory of Open Access Journals (Sweden)

    Gitima Patowary

    2011-11-01

    Full Text Available This paper investigates the influence of the material parameter, buoyancy parameter and Prandtl number on the skin friction coefficient and the heat transfer rate at the surface on a steady, two dimensional flow of an incompressible micropolar fluid near the stagnation point on a vertical plate with prescribed surface heat flux in presence of a magnetic filed. The free stream velocity and the surface heat flux are assumed to be proportional to the distance from the stagnation point. Similarly transformation is employed to transform the governing partial differential equations to a set of ordinary differential equations. The effects of the material parameter, buoyancy parameter and Prandtl number on the skin friction coefficient and the heat transfer rate at the surface are discussed and the corresponding velocity, temperature and microrotation profiles are shown graphically. Both assisting and opposing flows are considered and it is found that dual solutions exist for both cases

  11. Biological basis of “depression with liver-qi stagnation and spleen deficiency syndrome”: A digital gene expression profiling study

    Directory of Open Access Journals (Sweden)

    Junling Li

    2015-07-01

    Conclusions: Hnf4α, Hnf4γ and Cyp1a1 are involved in “depression with liver-qi stagnation and spleen deficiency syndrome”. These findings indicate that depressed rats with liver-qi stagnation and spleen deficiency syndrome are at risk of liver diseases. Furthermore, our results will inform exploration of the etiology of depression and help in the development of effective therapeutic strategies.

  12. Impact of Water Chemistry, Pipe Material and Stagnation on the Building Plumbing Microbiome.

    Directory of Open Access Journals (Sweden)

    Pan Ji

    Full Text Available A unique microbiome establishes in the portion of the potable water distribution system within homes and other buildings (i.e., building plumbing. To examine its composition and the factors that shape it, standardized cold water plumbing rigs were deployed at the treatment plant and in the distribution system of five water utilities across the U.S. Three pipe materials (copper with lead solder, CPVC with brass fittings or copper/lead combined pipe were compared, with 8 hour flush cycles of 10 minutes to simulate typical daily use patterns. High throughput Illumina sequencing of 16S rRNA gene amplicons was employed to profile and compare the resident bulk water bacteria and archaea. The utility, location of the pipe rig, pipe material and stagnation all had a significant influence on the plumbing microbiome composition, but the utility source water and treatment practices were dominant factors. Examination of 21 water chemistry parameters suggested that the total chlorine concentration, pH, P, SO42- and Mg were associated with the most of the variation in bulk water microbiome composition. Disinfectant type exerted a notably low-magnitude impact on microbiome composition. At two utilities using the same source water, slight differences in treatment approaches were associated with differences in rare taxa in samples. For genera containing opportunistic pathogens, Utility C samples (highest pH of 9-10 had the highest frequency of detection for Legionella spp. and lowest relative abundance of Mycobacterium spp. Data were examined across utilities to identify a true universal core, special core, and peripheral organisms to deepen insight into the physical and chemical factors that shape the building plumbing microbiome.

  13. Observation and Simulation of Ion Flow Stagnation in the Enceladus Plume

    Science.gov (United States)

    Tokar, R. L.; Omidi, N.; Averkamp, T.; Wang, Z.; Gurnett, D. A.; Thomsen, M. F.; Crary, F. J.

    2010-12-01

    The Cassini Plasma Spectrometer (CAPS) detected freshly-produced water-group ions (O+, OH+, H2O+, H3O+) and heavier charged water clusters (HxO2)+ very close to Enceladus within and outside of the south polar plume, see (1). The data were obtained during close flybys of Enceladus in 2008 and 2009 (E3, E5, E7) when CAPS viewing of the ion plasma was favorable. The ions are observed in CAPS detectors looking in the Cassini ram direction and close to the ram kinetic energy, indicative of a nearly stagnant (at rest with respect to Enceladus) plasma flow in the plume. In this study these CAPS observations are compared with 3D hybrid simulations of the Enceladus interaction (2). The primary goal is to simulate the spatial extent of the ion flow stagnation in and near the plume observed by CAPS. The simulations include not only plume water vapor undergoing charge exchange with the ambient ion flow but also heavy plume dust that acquires a negative charge. The neutral dust spatial distribution is modeled using particle impact rates obtained from Radio and Plasma Wave System (RPWS) data while plasma fluid parameters during the encounters are obtained from CAPS. The dust is a second heavy particle component in the simulation that is followed in the same manner as the positive ions. The dust absorption of electrons mass-loads the plasma producing flow deceleration observable by CAPS over the high impact regions measured by RPWS. This deceleration is compared with that due to the charge exchange process. 1.)Tokar,R.L. et al. Geophys. Res. Lett., 36, L13203, doi:10.1029/2009GL038923, 2009. 2.)Omidi,N. et al., J. Geophys. Res., 115, A05212, doi:10.1029/2009JA014391, 2010.

  14. Explorations in achievement motivation

    Science.gov (United States)

    Helmreich, Robert L.

    1982-01-01

    Recent research on the nature of achievement motivation is reviewed. A three-factor model of intrinsic motives is presented and related to various criteria of performance, job satisfaction and leisure activities. The relationships between intrinsic and extrinsic motives are discussed. Needed areas for future research are described.

  15. To compare the efficacy of two kinds of Zhizhu pills in the treatment of functional dyspepsia of spleen-deficiency and qi-stagnation syndrome:a randomized group sequential comparative trial

    Directory of Open Access Journals (Sweden)

    Huang Luqi

    2011-07-01

    Full Text Available Abstract Background In Traditional Chinese Medicine (TCM theory, functional dyspepsia (FD can be divided into different syndromes according to different clinical symptoms and signs, and the most common one is spleen-deficiency and qi-stagnation syndrome that can be treated by Chinese traditional patent medicine ---- two kinds of Zhizhu pills, between which the primary difference in ingredients is that one contains immature orange fruit of Citrus aurantium L.(IFCA and the other contains that of Citrus sinensis Osbeck (IFCS. The trial's objective was to compare the efficacy of two kinds of Zhizhu pills on symptom changes in patients with FD of spleen-deficiency and qi-stagnation syndrome. Methods A randomized, group sequential, double-blinded, multicenter trial was conducted in patients with FD of spleen-deficiency and qi-stagnation syndrome at 3 hospitals in Beijing between June 2003 and May 2005. Participants were randomly allocated into two groups (IFCA group and IFCS group in a 1:1 ratio, and respectively took one of the two kinds of Zhizhu pills orally, 6 g each time, 3 times a day, for 4 weeks. Statistical analysis was performed with use of a group sequential method, the triangular test (TT. Results A total of 163 patients were randomized, and 3 patients were excluded from analysis because of early dropouts, leaving 160 patients (IFCA group: n = 82; IFCS group: n = 78 for statistical analysis. Three interim analyses were done after 62, 116, and 160 patients had completed their 4-week treatment, respectively. At the third interim analysis, the sample path crossed the upper boundary and the trial was stopped, the cure-markedly effective rates were 45% for IFCS group and 67% for IFCA group, respectively, the one-sided p-value was 0.0036, the median unbiased estimate of the odds ratio (OR for the benefit of IFCA relative to IFCS was 2.91 with 95%CI: 1.40 to 6.06. No adverse events were observed in the two groups. Conclusions Zhizhu pills

  16. Students' Accounts of School-Performance Stress: A Qualitative Analysis of a High-Achieving Setting in Stockholm, Sweden

    Science.gov (United States)

    Låftman, Sara Brolin; Almquist, Ylva B.; Östberg, Viveca

    2013-01-01

    The aim of the study is to examine students' experiences of school performance as a stressor. Accounts of school-performance stress at both the individual level and in relation to group mechanisms are studied through qualitative interviews with eighth-grade students in a high-performing school in Stockholm, Sweden (n = 49). Using qualitative…

  17. Are Physical Activity and Academic Performance Compatible? Academic Achievement, Conduct, Physical Activity and Self-Esteem of Hong Kong Chinese Primary School Children

    Science.gov (United States)

    Yu, C. C. W.; Chan, Scarlet; Cheng, Frances; Sung, R. Y. T.; Hau, Kit-Tai

    2006-01-01

    Education is so strongly emphasized in the Chinese culture that academic success is widely regarded as the only indicator of success, while too much physical activity is often discouraged because it drains energy and affects academic concentration. This study investigated the relations among academic achievement, self-esteem, school conduct and…

  18. Autonomy Support and Achievement Goals as Predictors of Perceived School Performance and Life Satisfaction in the Transition between Lower and Upper Secondary School

    Science.gov (United States)

    Diseth, Åge; Samdal, Oddrun

    2014-01-01

    A self-determination theory perspective on motivation assumes that basic need support is a prerequisite for motivation, achievement, and well-being in several domains of life. In the present cross-sectional study, a representative sample of 2.594 Norwegian students in their final year of lower secondary education and their first year of upper…

  19. High Performing Schools in High Risk Environments: A Study on Leadership, School Safety, and Student Achievement at Two Urban Middle Schools in Los Angeles County

    Science.gov (United States)

    Frias, Gus

    2010-01-01

    In the United States of America, all students and staff have a constitutional right to attend schools that are safe, secure, and successful. Despite this right, at many public schools, education leaders have failed to ensure the safety and high academic achievement of all students. The purpose of this research study is to expand knowledge about…

  20. Feelings and Performance in the First Year at University: Learning-Related Emotions as Predictors of Achievement Outcomes in Mathematics and Statistics

    Science.gov (United States)

    Niculescu, Alexandra C.; Templelaar, Dirk; Leppink, Jimmie; Dailey-Hebert, Amber; Segers, Mien; Gijselaers, Wim

    2015-01-01

    Introduction: This study examined the predictive value of four learning-related emotions--Enjoyment, Anxiety, Boredom and Hopelessness for achievement outcomes in the first year of study at university. Method: We used a large sample (N = 2337) of first year university students enrolled over three consecutive academic years in a mathematics and…

  1. From nuclear stagnation to renaissance: The challenge of transferring regulatory knowledge

    International Nuclear Information System (INIS)

    Full text: Around 20 years ago there was a de facto nuclear stagnation of the peaceful uses of atomic energy in the West. At the time, governmental institutions for nuclear research and regulation, as well as the nuclear industry, had a nuclear 'intelligentsia' and many well qualified specialists available. Moreover, universities were ready and able to educate the next generation of professionals. The decline of the nuclear industry was therefore damaging both for individuals and the schools educating them. The options were few: for the workers, to restart a working life in other industries or to try to hang on until retirement; for the educational institutions, to abandon researching and teaching nuclear subjects. Now, however, an emerging energy crisis and growing environmental concerns about the burning of fossil fuels are inducing Western politicians to rethink the soundness of the decision to curtail the nuclear power industry. It therefore seems that there will be a nuclear renaissance, but that the qualified personnel to carry this out are no longer available, since in the intervening years they have changed jobs, retired or died. Put simply, the plentiful workforce responsible for last century's nuclear miracle is no longer there. Moreover, a cultural gap exists between the past and present generations, and such a lack of cultural continuity creates a difficult challenge for the traditional inter-generational knowledge transfer that has enabled development in the past. There are many reasons for this situation, and it will be for historians to explain them, but it is obvious that the Chernobyl accident and the public belief that nuclear installations were not safely regulated played a crucial role. At the time, nuclear regulatory authorities were less demanding, and in many countries they simply did not exist. Concepts such as regulatory independence and strengthening and safety culture are generally post-Chernobyl phenomena. Moreover, over the past decades

  2. Monetary Policy, Fiscal Policy, and Secular Stagnation at the Zero Lower Bound. A View on the Eurozone

    OpenAIRE

    Kleczka, Mitja

    2015-01-01

    This paper delivers a contemporary estimate of the Eurozone’s natural real rate of interest. While it is found that the natural real rate has declined substantially between 1997 and 2015, it has not become negative. Thus, even in the presence of low inflation and nominal interest rates at the zero lower bound, the Eurozone does not face an acute threat of secular stagnation as defined by Lawrence Summers. Similarly, it is deemed unlikely that a number of ‘headwinds’ or a demise of technologic...

  3. Radiation effects on MHD stagnation point flow of nano fluid towards a stretching surface with convective boundary condition

    Institute of Scientific and Technical Information of China (English)

    Noreen Sher Akbar; S. Nadeem; Rizwan Ul Haq; Z.H. Khan

    2013-01-01

    The aim of the present paper is to study the numerical solutions of the steady MHD two dimensional stagnation point flow of an incompressible nano fluid towards a stretching cylinder. The effects of radiation and convective boundary condition are also taken into account. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. The result-ing nonlinear momentum, energy and nano particle equations are simplified using similarity trans-formations. Numerical solutions have been obtained for the velocity, temperature and nanoparticle fraction profiles. The influence of physical parameters on the velocity, temperature, nanoparticle fraction, rates of heat transfer and nanoparticle fraction are shown graphically.

  4. Magnetic Field and Slip Effects on the Flow and Heat Transfer of Stagnation Point Jeffrey Fluid over Deformable Surfaces

    Science.gov (United States)

    Turkyilmazoglu, Mustafa

    2016-06-01

    The Mhd slip flow and heat transfer of stagnation point Jeffrey fluid over deformable surfaces are the state of the art of this article. Following an analytical approach, the existence, uniqueness, and possible multiplicity of the physical solutions affected by several physical parameters are investigated. Particularly, magnetic interaction and slip factor are shown to much influence the structure of the solutions regarding both momentum and thermal boundary layers. The presented exact solutions not only provide a clear understanding of fruitful physical mechanisms present in this nonlinear flow problem but they have also merits in calculations by means of numerous numerical schemes aiming to explore further complex phenomena.

  5. Unsteady Stagnation Point Flow and Heat Transfer over a Stretching/Shrinking Sheet with Suction or Injection

    Directory of Open Access Journals (Sweden)

    M. Suali

    2012-01-01

    Full Text Available The unsteady stagnation point flow and heat transfer over a stretching/shrinking sheet with suction/injection is studied. The governing partial differential equations are converted into nonlinear ordinary differential equations using a similarity transformation and solved numerically. Both stretching and shrinking cases are considered. Results for the skin friction coefficient, local Nusselt number, velocity, and temperature profiles are presented for different values of the governing parameters. It is found that the dual solutions exist for the shrinking case, whereas the solution is unique for the stretching case. Numerical results show that the range of dual solutions increases with mass suction and decreases with mass injection.

  6. Unsteady stagnation point flow and heat transfer over a stretching/shrinking sheet with prescribed surface heat flux

    Directory of Open Access Journals (Sweden)

    A. Ishak

    2012-08-01

    Full Text Available An analysis is carried out to study the unsteady two dimensional stagnation point flow and heat transfer over a stretching/shrinking sheet with prescribed surface heat flux. The governing partial differential equations are converted into nonlinear ordinary differential equations using similarity variables, and solved numerically. The effects of the unsteadiness parameter A, stretching/shrinking parameter ε and Prandtl number Pr on the flow and heat transfer characteristics are studied. It is found that the skin friction f′′(0 and the local Nusselt number 1θ(0 increase as the the unsteadiness parameter A increases. Moreover, the velocity and temperature increase as ε and Pr increase.

  7. Finite-Difference Implementation of Inviscid Separated Flows with Infinitely-Long Cusp-Ended Stagnation Zone around Circular Cylinder

    CERN Document Server

    Todorov, M D

    1998-01-01

    The classical Helmholtz problem is applied for modelling and numerical investigation of inviscid cusp-ended separated flow around circular cylinder. Two coordinate systems are used: polar for initial calculations and parabolic as topologically most suited for infinite stagnation zone. Scaling by the shape of the unknown free line renders the problem to computational domain with fixed boundaries. Difference schemes and algorithm for Laplace equation and for Bernoulli integral are devised. A separated flow with drag coefficient $C_x=0$ like the so called ``critical'' flow is obtained. The pressure distribution on the surface of cylinder and the detachment point compares quantitatively very well with the predictions of the hodograph method.

  8. Improving Teacher Effectiveness: An Examination of a Pay for Performance Plan for Boosting Student Academic Achievement in Charlotte-Mecklenburg Schools

    Science.gov (United States)

    Ngoma, Sylvester

    2011-01-01

    Throughout the United States, educational organizations are striving to find more effective ways to improve teacher performance and student learning. The increased pressure to improve teacher effectiveness in the classroom has led many public school districts to adopt a pay for performance system as a strategic compensation option for enhancing…

  9. Which Feedback Is More Effective for Pursuing Multiple Goals of Differing Importance? The Interaction Effects of Goal Importance and Performance Feedback Type on Self-Regulation and Task Achievement

    Science.gov (United States)

    Lee, Hyunjoo

    2016-01-01

    This study examined how performance feedback type (progress vs. distance) affects Korean college students' self-regulation and task achievement according to relative goal importance in the pursuit of multiple goals. For this study, 146 students participated in a computerised task. The results showed the interaction effects of goal importance and…

  10. Achieving ICME with Multiscale Modeling: The Effects of Constituent Properties and Processing on the Performance of Laminated Polymer Matrix Composite Structures

    Science.gov (United States)

    Pineda, Evan Jorge; Bednarcyk, Brett A.; Arnold, Steven M.

    2014-01-01

    Integrated computational materials engineering (ICME) is a useful approach for tailoring the performance of a material. For fiber-reinforced composites, not only do the properties of the constituents of the composite affect the performance, but so does the architecture (or microstructure) of the constituents. The generalized method of cells is demonstrated to be a viable micromechanics tool for determining the effects of the microstructure on the performance of laminates. The micromechanics is used to predict the inputs for a macroscale model for a variety of different fiber volume fractions, and fiber architectures. Using this technique, the material performance can be tailored for specific applications by judicious selection of constituents, volume fraction, and architectural arrangement given a particular manufacturing scenario

  11. Closing the social-class achievement gap: a difference-education intervention improves first-generation students' academic performance and all students' college transition.

    Science.gov (United States)

    Stephens, Nicole M; Hamedani, MarYam G; Destin, Mesmin

    2014-04-01

    College students who do not have parents with 4-year degrees (first-generation students) earn lower grades and encounter more obstacles to success than do students who have at least one parent with a 4-year degree (continuing-generation students). In the study reported here, we tested a novel intervention designed to reduce this social-class achievement gap with a randomized controlled trial (N = 168). Using senior college students' real-life stories, we conducted a difference-education intervention with incoming students about how their diverse backgrounds can shape what they experience in college. Compared with a standard intervention that provided similar stories of college adjustment without highlighting students' different backgrounds, the difference-education intervention eliminated the social-class achievement gap by increasing first-generation students' tendency to seek out college resources (e.g., meeting with professors) and, in turn, improving their end-of-year grade point averages. The difference-education intervention also improved the college transition for all students on numerous psychosocial outcomes (e.g., mental health and engagement). PMID:24553359

  12. Measurement of Perceived Parental Success Standards in Sport and Relations with Athletes’ Self-Esteem, Performance Anxiety, and Achievement Goal Orientation: Comparing Parental and Coach Influences

    Directory of Open Access Journals (Sweden)

    Frank J. Schwebel

    2016-01-01

    Full Text Available The Perceived Parent Success Standards Scale (PPSSS, adapted from the Perception of Success Questionnaire constructed by Roberts et al. (1998 to measure athletes’ achievement goal orientation, provides a measure of athletes’ perceptions of mastery- and ego-oriented parental success criteria, a central component of parental motivational climate. This study focused on 543 young athletes (ages 9–16 on 82 teams in recreational basketball leagues. The PPSSS exhibited strong factorial validity, construct validity, and orthogonality between ego and mastery factors that allow for different combinations of these factors to be tested. We also compared the impact of the motivational climates created by coaches and success standards conveyed by parents on postseason athlete outcome measures of anxiety, self-esteem, and achievement goal orientation. Correlational and multilevel regression analyses revealed that both coach and parent variables were significantly related to the athlete variables. However, mediational analyses indicated that parental success standards mediated relations between coach-initiated climate and all of the outcome variables, reflecting the power of parental socialization processes. We discuss potential reasons for the greater parental influence shown in this and a previous study, and we suggest directions for further research as well as possible interventions that can help both coaches and parents create a more positive athletic environment for young athletes.

  13. Closing the social-class achievement gap: a difference-education intervention improves first-generation students' academic performance and all students' college transition.

    Science.gov (United States)

    Stephens, Nicole M; Hamedani, MarYam G; Destin, Mesmin

    2014-04-01

    College students who do not have parents with 4-year degrees (first-generation students) earn lower grades and encounter more obstacles to success than do students who have at least one parent with a 4-year degree (continuing-generation students). In the study reported here, we tested a novel intervention designed to reduce this social-class achievement gap with a randomized controlled trial (N = 168). Using senior college students' real-life stories, we conducted a difference-education intervention with incoming students about how their diverse backgrounds can shape what they experience in college. Compared with a standard intervention that provided similar stories of college adjustment without highlighting students' different backgrounds, the difference-education intervention eliminated the social-class achievement gap by increasing first-generation students' tendency to seek out college resources (e.g., meeting with professors) and, in turn, improving their end-of-year grade point averages. The difference-education intervention also improved the college transition for all students on numerous psychosocial outcomes (e.g., mental health and engagement).

  14. Standard Practice for Exposure of Solar Collector Cover Materials to Natural Weathering Under Conditions Simulating Stagnation Mode

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1992-01-01

    1.1 This practice covers a procedure for the exposure of solar collector cover materials to the natural weather environment at elevated temperatures that approximate stagnation conditions in solar collectors having a combined back and edge loss coefficient of less than 1.5 W/(m2 · °C). 1.2 This practice is suitable for exposure of both glass and plastic solar collector cover materials. Provisions are made for exposure of single and double cover assemblies to accommodate the need for exposure of both inner and outer solar collector cover materials. 1.3 This practice does not apply to cover materials for evacuated collectors, photovoltaic cells, flat-plate collectors having a combined back and edge loss coefficient greater than 1.5 W/(m2 ·° C), or flat-plate collectors whose design incorporates means for limiting temperatures during stagnation. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard t...

  15. Comparison of volatility distributions in the periods of booms and stagnations: an empirical study on stock price indices

    CERN Document Server

    Kaizoji, T

    2005-01-01

    The aim of this paper is to compare statistical properties of stock price indices in periods of booms with those in periods of stagnations. We use the daily data of the four stock price indices in the major stock markets in the world: (i) the Nikkei 225 index (Nikkei 225) from January 4, 1975 to August 18, 2004, of (ii) the Dow Jones Industrial Average (DJIA) from January 2, 1946 to August 18, 2004, of (iii) Standard and Poor's 500 index (SP500) from November 22, 1982 to August 18, 2004, and of (iii) the Financial Times Stock Exchange 100 index (FT 100) from April 2, 1984 to August 18, 2004. We divide the time series of each of these indices in the two periods: booms and stagnations, and investigate the statistical properties of absolute log returns, which is a typical measure of volatility, for each period. We find that (i) the tail of the distribution of the absolute log-returns is approximated by a power-law function with the exponent close to 3 in the periods of booms while the distribution is described b...

  16. The effect of mixing rates on the formation and growth of condensation aerosols in a model stagnation flow

    KAUST Repository

    Alshaarawi, Amjad

    2015-03-01

    A steady, laminar stagnation flow configuration is adopted to investigate numerically the interaction between condensing aerosol particles and gas-phase transport across a canonical mixing layer. The mixing rates are varied by adjusting the velocity and length scales of the stagnation flow parametrically. The effect of mixing rates on particle concentration, polydispersity, and mean droplet diameter is explored and discussed. This numerical study reveals a complex response of the aerosol to varying flow times. Depending on the flow time, the variation of the particle concentration in response to varying mixing rates falls into one of the two regimes. For fast mixing rates, the number density and volume fraction of the condensing particles increase with residence time (nucleation regime). On the contrary, for low mixing rates, number density decreases with residence time and volume fraction reaches a plateau (condensation regime). It is shown that vapor scavenging by the aerosol phase is key to explaining the transition between these two regimes. The results reported here are general and illustrate genuine features of the evolution of aerosols forming by condensation of supersaturated vapor from heat and mass transport across mixing layers.

  17. Single-Atom Pd₁/Graphene Catalyst Achieved by Atomic Layer Deposition: Remarkable Performance in Selective Hydrogenation of 1,3-Butadiene.

    Science.gov (United States)

    Yan, Huan; Cheng, Hao; Yi, Hong; Lin, Yue; Yao, Tao; Wang, Chunlei; Li, Junjie; Wei, Shiqiang; Lu, Junling

    2015-08-26

    We reported that atomically dispersed Pd on graphene can be fabricated using the atomic layer deposition technique. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure spectroscopy both confirmed that isolated Pd single atoms dominantly existed on the graphene support. In selective hydrogenation of 1,3-butadiene, the single-atom Pd1/graphene catalyst showed about 100% butenes selectivity at 95% conversion at a mild reaction condition of about 50 °C, which is likely due to the changes of 1,3-butadiene adsorption mode and enhanced steric effect on the isolated Pd atoms. More importantly, excellent durability against deactivation via either aggregation of metal atoms or carbonaceous deposits during a total 100 h of reaction time on stream was achieved. Therefore, the single-atom catalysts may open up more opportunities to optimize the activity, selectivity, and durability in selective hydrogenation reactions. PMID:26268551

  18. Achieving high performance non-fullerene organic solar cells through tuning the numbers of electron deficient building blocks of molecular acceptors

    Science.gov (United States)

    Yang, Lei; Chen, Yusheng; Chen, Shangshang; Dong, Tao; Deng, Wei; Lv, Lei; Yang, Saina; Yan, He; Huang, Hui

    2016-08-01

    Two analogous dimer and tetramer compounds, SF-PDI2 and SF-PDI4, were designed, theoretically calculated, synthesized, and developed as electron acceptors for organic solar cells. The effects of the number of the electron deficient building blocks on the optical absorption, energy levels, charge transport, morphology, crystallinity, and photovoltaic performance of the molecules were investigated. In combination with two different donors, PTB7-Th and PffBT4T-2OD, the results showed that increasing the numbers of PDI building blocks is beneficial to photovoltaic performance and leads to efficiency over 5%.

  19. The effect of parental education, prior achievement, self-efficacy, goal orientation, and effort on undergraduate science performance of Latinos and Caucasians

    Science.gov (United States)

    Stansbury, Sydney Lynn

    Compared with majority students, underrepresented minorities have demonstrated weaker undergraduate science performance. Previous research has attributed the weaker performance to socioeconomic factors that influence poorer precollege preparation. Studies also have found that, compared with majority students, underrepresented minorities are less confident about their science skills and more interested in extrinsic rewards of science careers. Social Cognitive Theory posits that low self-efficacy coupled with high extrinsic goal orientation diminishes cognitive engagement, resulting in weak performance. Applying motivational characteristics of underrepresented minority students to a Social Cognitive Model may explain why their performance is weaker than that of Caucasians. Thus, the purpose of this study was to investigate the degree to which motivation variables account for the difference between underrepresented minority and majority students' undergraduate science performance. The study was conducted at a large, predominantly Caucasian, private university located in an urban setting in the Southwest. Two hundred twenty-two students--154 Caucasians and 68 Latinos--enrolled in a general chemistry course participated. Students were administered the Motivation for Learning Questionnaire, designed specifically for this study, consisting of scales measuring the following variables: ethnicity, level of parental education, and effort exertion; self-efficacy, effort regulation, intrinsic goal orientation, and extrinsic goal orientation, measures from the Motivated Strategies for Learning Questionnaire (Pintrich, Smith, Garcia, & McKeachie, 1991); and ability orientation, a measure from the Patterns of Adaptive Learning Survey (Midgley, Maehr, & Urdan, 1995). Financial aid information, chemistry and math placement test scores, and chemistry grades were obtained from other on-campus departments. Results demonstrated that the hypotheses were only partially confirmed by the

  20. 再论"诸病兼从郁治"%Removing Stagnation as Adjuvant Treatment for All Diseases: A Further Discussion

    Institute of Scientific and Technical Information of China (English)

    黄琰

    2011-01-01

    The close relationship between exogenous pathogenic factors induced diseases and stagnation syndrome was discussed based on " Huangdi’s Classic on Medicine" , " Treatise on Febrile Diseases " , and the theory of epidemic febrile diseases; and the close relationship between stagnation syndrome and miscellaneous diseases was discussed by taking hysteria, globus hystericus, dizziness, esophageal cancer, chest pain, abdominal pain, and lumbago as examples. Therefore, it is suggested that removing stagnation should be used as adjuvant treatment for all diseases.%从、及温病学说角度论述郁与外感病的密切关系,并以脏躁、梅核气、眩晕、噎膈、心腹痛、腰痛为例论述郁与内伤杂病的密切关系,从而论证了"诸病兼从郁治"的观点.

  1. The Effect of Evaluation on Performance: Evidence from Longitudinal Student Achievement Data of Mid-Career Teachers. NBER Working Paper No. 16877

    Science.gov (United States)

    Taylor, Eric S.; Tyler, John H.

    2011-01-01

    The effect of evaluation on employee performance is traditionally studied in the context of the principal-agent problem. Evaluation can, however, also be characterized as an investment in the evaluated employee's human capital. We study a sample of mid-career public school teachers where we can consider these two types of evaluation effect…

  2. Graded Achievement, Tested Achievement, and Validity

    Science.gov (United States)

    Brookhart, Susan M.

    2015-01-01

    Twenty-eight studies of grades, over a century, were reviewed using the argument-based approach to validity suggested by Kane as a theoretical framework. The review draws conclusions about the meaning of graded achievement, its relation to tested achievement, and changes in the construct of graded achievement over time. "Graded…

  3. Restaurant-bar strategic behaviors in Oulu city centre 2014: analysis of competitive advantage, performance patterns and success-achievement results

    OpenAIRE

    Vera de la Rosa, Oscar Eduardo

    2014-01-01

    The objective is to measure direct and indirect competitors’ operating strategies, in order to evaluate their performance and make comparisons. The results are essential information for Coyoacán restaurant that will open on November 2014 on the street of Hallituskatu number 27. The 5 companies chosen represent the median values of all the competitors under a 93.75% certainty. The chosen “Subjects of Study” are: 1) Burgeribaari Kauppuri 5 (Bar & Grill Kauppuri 5 Oy) Fast-Food/Ba...

  4. THE EFFECT OF PERFORMANCE ASSESSMENT APPROACH TO THE STUDENTS' LEVEL OF ACHIEVEMENT AND ATTITUDE OF THE STUDENTS FOR TEACHING SOCIAL STUDIES

    OpenAIRE

    Elvan YALÇINKAYA

    2010-01-01

    The aim of this study is to investigate how the performance assessment approach effect students' academic success and attitude towards lessons at social studies lessons. The study model is designed as experimental design with pre test post test control group. The control group include 23 students, experiment group include 23 students and there are total 46 students. Economy and Social Life unit is studied with control group students by lesson book based approach and traditional assesment is ...

  5. Enhanced in Vitro and in Vivo Performance of Mg-Zn-Y-Nd Alloy Achieved with APTES Pretreatment for Drug-Eluting Vascular Stent Application.

    Science.gov (United States)

    Liu, Jing; Zheng, Bo; Wang, Pei; Wang, Xingang; Zhang, Bin; Shi, Qiuping; Xi, Tingfei; Chen, Ming; Guan, Shaokang

    2016-07-20

    Bioabsorbable magnesium alloys are becoming prominent as temporary functional implants, as they avoid the risks generated by permanent metallic implants such as persistent inflammation and late restenosis. Nevertheless, the overfast corrosion of Mg alloys under physiological conditions hinders their wider application as medical implant materials. Here we investigate a simple one-step process to introduce a cross-linked 3-amino-propyltrimethoxysilane (APTES) silane physical barrier layer on the surface of Mg-Zn-Y-Nd alloys prior to electrostatic spraying with rapamycin-eluting poly(lactic-co-glycolic acid) (PLGA) layer. Surface microstructure was characterized by scanning electron microscope and Fourier transform infrared spectroscopy. Nanoscratch test verified the superior adhesion strength of PLGA coating in the group pretreated with APTES. Electrochemical tests combined with long-term immersion results suggested that the preferable in vitro anticorrosion behavior could be achieved by dense APTES barrier. Cell morphology and proliferation data demonstrated that APTES pretreated group resulted in remarkably preferable compatibility for both human umbilical vein endothelial cells and vascular smooth muscle cells. On the basis of excellent in vitro mechenical property, the animal study on the APTES pretreated Mg-Zn-Y-Nd stent implanted into porcine coronary arteries confirmed benign tissue compatibility as well as re-endothelialization without thrombogenesis or in-stent restenosis at six-month followup. PMID:27331417

  6. Highly Functional TNTs with Superb Photocatalytic, Optical, and Electronic Performance Achieving Record PV Efficiency of 10.1% for 1D-Based DSSCs.

    Science.gov (United States)

    Qadir, Muhammad Bilal; Li, Yuewen; Sahito, Iftikhar Ali; Arbab, Alvira Ayoub; Sun, Kyung Chul; Mengal, Naveed; Memon, Anam Ali; Jeong, Sung Hoon

    2016-09-01

    Different nanostructures of TiO2 play an important role in the photocatalytic and photoelectronic applications. TiO2 nanotubes (TNTs) have received increasing attention for these applications due to their unique physicochemical properties. Focusing on highly functional TNTs (HF-TNTs) for photocatalytic and photoelectronic applications, this study describes the facile hydrothermal synthesis of HF-TNTs by using commercial and cheaper materials for cost-effective manufacturing. To prove the functionality and applicability, these TNTs are used as scattering structure in dye-sensitized solar cells (DSSCs). Photocatalytic, optical, Brunauer-Emmett-Teller (BET), electrochemical impedance spectrum, incident-photon-to-current efficiency, and intensity-modulated photocurrent spectroscopy/intensity-modulated photovoltage spectroscopy characterizations are proving the functionality of HF-TNTs for DSSCs. HF-TNTs show 50% higher photocatalytic degradation rate and also 68% higher dye loading ability than conventional TNTs (C-TNTs). The DSSCs having HF-TNT and its composite-based multifunctional overlayer show effective light absorption, outstanding light scattering, lower interfacial resistance, longer electron lifetime, rapid electron transfer, and improved diffusion length, and consequently, J SC , quantum efficiency, and record photoconversion efficiency of 10.1% using commercial N-719 dye is achieved, for 1D-based DSSCs. These new and highly functional TNTs will be a concrete fundamental background toward the development of more functional applications in fuel cells, dye-sensitized solar cells, Li-ion batteries, photocatalysis process, ion-exchange/adsorption process, and photoelectrochemical devices. PMID:27432775

  7. 28 CFR 545.28 - Achievement awards.

    Science.gov (United States)

    2010-07-01

    ... COMPENSATION Inmate Work and Performance Pay Program § 545.28 Achievement awards. (a) With prior approval of... achievement award from performance pay funds. (b) With prior approval of the Psychology Services Department... also be granted an achievement award from performance pay funds....

  8. Investigation of 4H-SiC insulated-gate bipolar transistor turn-off performance for achieving low power loss

    Science.gov (United States)

    Navarro, Dondee; Pesic, Iliya; Morikawa, Yoji; Furui, Yoshiharu; Miura-Mattausch, Mitiko

    2016-04-01

    The dynamic characteristics of a 4H-SiC insulated-gate bipolar transistor (IGBT) at pulse switching is investigated by incorporating reported measurements of the interface defect density to device simulation. Different trap features such as energy states and trap time constants are investigated to determine the influence of traps on circuit performance. The capture cross-section parameter used in the simulation depicts the probability of traps to trap/detrap carriers which relates to the carrier trap time constant. It is demonstrated that trapped carriers from the on-state condition cause enhanced generation current during the off-state condition, which give rise to undesired leakage current in addition to the threshold voltage shift previously reported. The device power dissipation is increased by a factor of 100 due to the defects.

  9. The Effects of Chronic Achievement Motivation and Achievement Primes on the Activation of Achievement and Fun Goals

    OpenAIRE

    Hart, William; Albarracín, Dolores

    2009-01-01

    This research examined the hypothesis that situational achievement cues can elicit achievement or fun goals depending on chronic differences in achievement motivation. In 4 studies, chronic differences in achievement motivation were measured, and achievement-denoting words were used to influence behavior. The effects of these variables were assessed on self-report inventories, task performance, task resumption following an interruption, and the pursuit of means relevant to achieving or having...

  10. MHD Stagnation-Point Flow and Heat Transfer with Effects of Viscous Dissipation, Joule Heating and Partial Velocity Slip

    Science.gov (United States)

    Mat Yasin, Mohd Hafizi; Ishak, Anuar; Pop, Ioan

    2015-12-01

    The steady two-dimensional stagnation-point flow and heat transfer past a permeable stretching/shrinking sheet with effects of viscous dissipation, Joule heating and partial velocity slip in the presence of a magnetic field is investigated. The partial differential equations are reduced to nonlinear ordinary differential equations by using a similarity transformation, before being solved numerically by shooting technique. Results indicate that the skin friction coefficient and the local Nusselt number increase as magnetic parameter increases. It is found that for the stretching sheet the solution is unique while for the shrinking sheet there exist nonunique solutions (dual solutions) in certain range of parameters. The stability analysis shows that the upper branch solution is stable while the lower branch solution is unstable.

  11. Effects of induced magnetic field and homogeneous–heterogeneous reactions on stagnation flow of a Casson fluid

    Directory of Open Access Journals (Sweden)

    C.S.K. Raju

    2016-06-01

    Full Text Available In this study, we analyzed the induced magnetic field effect on the stagnation-point flow of a non-Newtonian fluid over a stretching sheet with homogeneous–heterogeneous reactions and non-uniform heat source or sink. The transformed ordinary differential equations are solved numerically using Runge–Kutta and Newton's method. For physical relevance we analyzed the behavior of homogeneous and heterogeneous profiles individually in the presence of induced magnetic field. The effects of different non-dimensional governing parameters on velocity, induced magnetic field, temperature and concentration profiles, along with the skin friction coefficient and local Nusselt number, are discussed and presented through graphs. The results of the present study are validated by comparing with the existed literature. Results indicate that induced magnetic field parameter and stretching ratio parameter have the tendency to enhance the heat transfer rate.

  12. Analytical solution to stagnation-point flow and heat transfer over a stretching sheet based on homotopy analysis

    Institute of Scientific and Technical Information of China (English)

    Jing ZHU; Lian-cun ZHENG; Xin-xin ZHANG

    2009-01-01

    This paper is concerned with two-dimensional stagnation-point steady flow of an incompressible viscous fluid towards a stretching sheet whose velocity is proportional to the distance from the slit. The governing system of partial differential equations is first transformed into a system of dimensionless ordinary differential equations. Analytical solutions of the velocity distribution and dimensionless temperature profiles are obtained for different ratios of free stream velocity and stretching velocity, Prandtl number, Eckert number and dimensionality index in series forms using homotopy analysis method(HAM).It is shown that a boundary layer is formed when the free stream velocity exceeds the stretching velocity, and an inverted boundary layer is formed when the free stream velocity is less than the stretching velocity. Graphs are presented to show the effects of different parameters.

  13. MHD Stagnation-Point Flow and Heat Transfer with Effects of Viscous Dissipation, Joule Heating and Partial Velocity Slip.

    Science.gov (United States)

    Yasin, Mohd Hafizi Mat; Ishak, Anuar; Pop, Ioan

    2015-01-01

    The steady two-dimensional stagnation-point flow and heat transfer past a permeable stretching/shrinking sheet with effects of viscous dissipation, Joule heating and partial velocity slip in the presence of a magnetic field is investigated. The partial differential equations are reduced to nonlinear ordinary differential equations by using a similarity transformation, before being solved numerically by shooting technique. Results indicate that the skin friction coefficient and the local Nusselt number increase as magnetic parameter increases. It is found that for the stretching sheet the solution is unique while for the shrinking sheet there exist nonunique solutions (dual solutions) in certain range of parameters. The stability analysis shows that the upper branch solution is stable while the lower branch solution is unstable. PMID:26647651

  14. Heat transfer in boundary layer stagnation-point flow towards a shrinking sheet with non-uniform heat flux

    Institute of Scientific and Technical Information of China (English)

    Krishnendu Bhattacharyya

    2013-01-01

    In this paper,the effect of non-uniform heat flux on heat transfer in boundary layer stagnation-point flow over a shrinking sheet is studied.The variable boundary heat fluxes are considered of two types:direct power-law variation with the distance along the sheet and inverse power-law variation with the distance.The governing partial differential equations (PDEs) are transformed into non linear self-similar ordinary differential equations (ODEs) by similarity transformations,and then those are solved using very efficient shooting method.The direct variation and inverse variation of heat flux along the sheet have completely different effects on the temperature distribution.Moreover,the heat transfer characteristics in the presence of non-uniform heat flux for several values of physical parameters are also found to be interesting.

  15. Mixed convection flow of a viscoelastic fluid near the orthogonal stagnation-point on a vertical surface

    Energy Technology Data Exchange (ETDEWEB)

    Li, D. [Department of Mathematics and Statistics, University of Regina, Regina, SK S4S 0A2 (Canada); Labropulu, F. [Luther College e Mathematics, University of Regina, Regina, SK S4S 0A2 (Canada); Pop, I. [Faculty of Mathematics, University of Cluj, R-3400 Cluj, CP 253 (Romania)

    2011-09-15

    An analysis of the steady mixed convection flow of a viscoelastic fluid stagnating orthogonally on a heated or cooled vertical flat plate has been studied. Using similarity variables, the governing equations are transformed into a system of two coupled non-linear ordinary differential equations. The resulting equations are then solved numerically using the spectral method. It is observed that the skin friction coefficient and the local heat transfer are decreasing when the Weissenberg number We is increasing in both assisting and opposing flow cases. On the other hand, the skin friction is decreasing and the local heat transfer is increasing when the Prandtl number Pr is increasing in the case of assisting flow. In the case of opposing flow, the skin friction and the local heat transfer are increasing as Pr is increasing. (authors)

  16. Stagnation-Point Flow and Heat Transfer over a Nonlinearly Stretching/Shrinking Sheet in a Micropolar Fluid

    Directory of Open Access Journals (Sweden)

    Khairy Zaimi

    2014-01-01

    Full Text Available This paper considers the problem of a steady two-dimensional stagnation-point flow and heat transfer of an incompressible micropolar fluid over a nonlinearly stretching/shrinking sheet. A similarity transformation is employed to convert the partial differential equations into nonlinear ordinary ones which are then solved numerically using a shooting method. Numerical results obtained are presented graphically, showing the effects of the micropolar or material parameter and the stretching/shrinking parameter on the flow field and heat transfer characteristics. The dual solutions are found to exist in a limited range of the stretching/shrinking parameter for the shrinking case, while unique solutions are possible for all positive values of the stretching/shrinking parameter (stretching case. It is also observed that the skin friction coefficient and the magnitude of the local Nusselt number increase as the material parameter increases.

  17. Performance Requirements to Achieve Cost-Effectiveness of Point-of-Care Tests for Sepsis Among Patients with Febrile Illness in Low-Resource Settings.

    Science.gov (United States)

    Penno, Erin C; Crump, John A; Baird, Sarah J

    2015-10-01

    Bacterial sepsis is an important cause of mortality in low- and middle-income countries, yet distinguishing patients with sepsis from those with other illnesses remains a challenge. Currently, management decisions are based on clinical assessment using algorithms such as Integrated Management of Adolescent and Adult Illness. Efforts to develop and evaluate point-of-care tests (POCTs) for sepsis to guide decisions on the use of antimicrobials are underway. To establish the minimum performance characteristics of such a test, we varied the characteristics of a hypothetical POCT for sepsis required for it to be cost-effective and applied a decision tree model to a population of febrile patients presenting at the district hospital level in a low-resource setting. We used a case fatality probability of 20% for appropriately treated sepsis and of 50% for inappropriately treated sepsis. On the basis of clinical assessment for sepsis with established sensitivity of 0.83 and specificity of 0.62, we found that a POCT for sepsis with a sensitivity of 0.83 and a specificity of 0.94 was cost-effective, resulting in parity in survival but costing $1.14 less per live saved. A POCT with accuracy equivalent to the best malaria rapid diagnostic test was cheaper and more effective than clinical assessment. PMID:26195467

  18. Achieving high performance electric field induced strain: a rational design of hyperbranched aromatic polyamide functionalized graphene-polyurethane dielectric elastomer composites.

    Science.gov (United States)

    Chen, Tian; Qiu, Jinhao; Zhu, Kongjun; Li, Jinhuan; Wang, Jingwen; Li, Shuqin; Wang, Xiaoliang

    2015-03-26

    Dielectric elastomers have great potentials as flexible actuators in micro-electromechanical systems (MEMS) due to their large deformation, light weight, mechanical compliancy, and low cost. The low dielectric constant of these elastomers requires a rather high voltage electric field, which has greatly limited their applications. In this work, a diaphragm-type flexible microactuator comprising a hyperbranched aromatic polyamide functionalized graphene (HAPFG) filler embedded into the polyurethane (PU) dielectric elastomer matrix is described. The rational designed HAPFG sheets exhibits uniform dispersion in PU matrix and strong adhesion with the matrix by hydrogen-bond coupling. Consequently, the HAPFG-PU composites possess high dielectric performance and low loss modulus. The effect of hyperbranched aromatic polyamide functionalized graphene on high voltage electric field induced strain was experimentally investigated using the Fotonic sensor. The high electric field response of the composite was discussed by applying different kinds of alternating-current field. In addition, a comparison of the breakdown strength between the HAPFG-PU composite and the pure PU was carried out. PMID:25741878

  19. The Predictiveness of Achievement Goals

    Directory of Open Access Journals (Sweden)

    Huy P. Phan

    2013-11-01

    Full Text Available Using the Revised Achievement Goal Questionnaire (AGQ-R (Elliot & Murayama, 2008, we explored first-year university students’ achievement goal orientations on the premise of the 2 × 2 model. Similar to recent studies (Elliot & Murayama, 2008; Elliot & Thrash, 2010, we conceptualized a model that included both antecedent (i.e., enactive learning experience and consequence (i.e., intrinsic motivation and academic achievement of achievement goals. Two hundred seventy-seven university students (151 women, 126 men participated in the study. Structural equation modeling procedures yielded evidence that showed the predictive effects of enactive learning experience and mastery goals on intrinsic motivation. Academic achievement was influenced intrinsic motivation, performance-approach goals, and enactive learning experience. Enactive learning experience also served as an antecedent of the four achievement goal types. On the whole, evidence obtained supports the AGQ-R and contributes, theoretically, to 2 × 2 model.

  20. The performance of small scale multi-generation technologies in achieving cost-optimal and zero-energy office building solutions

    International Nuclear Information System (INIS)

    Highlights: • The cost-optimal solutions for a new office building in Finland are obtained. • The EBPD comparative framework methodology is followed. • Biomass CHPs with high overall efficiency and low P/H ratio are economically viable. • Biomass CCHPs do not have economic or environmental benefits over biomass CHPs. • Extending the cost-optimal solutions by PV system yields NZEB with minimum LCC. - Abstract: This study investigates the economic viability of small-scale, multi-generation systems (combined heat and power (CHP), combined cooling, heating, and power (CCHP)), along with conventional heating and cooling systems combining sixteen heating/cooling energy generation systems (H/C-EGSs). The Energy Performance of Buildings Directive (EBPD) comparative framework methodology is followed. The local cost-optimal solution for an office building, in Helsinki, Finland is determined for each H/C-EGS as well as the global cost-optimum. The suggested energy efficiency measures get 144 building combinations, and alongside the H/C-EGSs, altogether 2304 cases. The results show that the global cost-optimum belongs to the ground source heat pump with free ground cooling. The investigated biomass-based CHPs are economically viable only with high overall efficiency and low power-to-heat ratio due to both low investment and operational costs. The biomass-based CCHPs do not have economic or environmental benefits over the biomass-based CHPs due to the significant increase entailed of both investment and operational costs. The fossil fuel-based CHPs with high operational costs are the worst solutions economically and environmentally. Extending the cost optimal solutions by a photovoltaic panels system yields the net zero-energy office building with minimum life-cycle costs as well

  1. Relationship between Gastro-esophageal Reflux Disease and the Stagnation Theory%从郁论治胃食管反流病探析

    Institute of Scientific and Technical Information of China (English)

    刘仁昌; 王光铭; 李春婷

    2012-01-01

    从气结为郁、痰积为郁、湿蕴为郁、瘀留为郁四方面阐述了郁之理论在胃食管反流病中形成的机理,以疏肝行气法、化痰降浊法、清热除湿法、祛瘀通络法作为开郁以治疗胃食管反流病的具体治法,并为其治法在临床治疗中提供了佐证.%To explain the importance of stagnation theory in treating gastro-esophageal reflux disease by four parts which is stagnation of Qi, stagnation of Phlegm, stagnation of dampness and blood stasis. With the evidence in how to treat gastro-esophageal reflux disease in clinic, the main treatment is smoothing the liver Qi, eliminating the phlegm, clearing away dampness-heat, removing the blood stasis to free collaterals.

  2. Bacterial deposition to fluoridated and non-fluoridated polyurethane coatings with different elastic modulus and surface tension in a parallel plate and a stagnation point flow chamber

    NARCIS (Netherlands)

    Bakker, D.P.; Huijs, F.M.; Vries, J. de; Klijnstra, J.W.; Busscher, H.J.; Mei, H.C. van der

    2003-01-01

    Deposition of three marine bacterial strains with different cell surface hydrophobicities from artificial seawater to polyurethane coatings on glass with different surface tensions and elastic modulus was studied in situ in a parallel plate (PP) and stagnation point (SP) flow chamber. Different surf

  3. Bacterial deposition in a parallel plate and a stagnation point flow chamber : microbial adhesion mechanisms depend on the mass transport conditions

    NARCIS (Netherlands)

    Bakker, DP; Busscher, HJ; van der Mei, HC

    2002-01-01

    Deposition onto glass in a parallel plate (PP) and in a stagnation point (SP) flow chamber of Marinobacter hydrocarbonoclasticus, Psychrobacter sp. and Halomonas pacifica, suspended in artificial seawater, was compared in order to determine the influence of methodology on bacterial adhesion mechanis

  4. Deposition of oral bacteria and polystyrene particles to quartz and dental enamel in a parallel plate and stagnation point flow chamber

    NARCIS (Netherlands)

    Yang, JL; Belder, GF; Busscher, HJ; Bos, R.R.M.

    1999-01-01

    The aim of this paper is to determine to what extent (i) deposition of oral bacteria and polystyrene particles, (ii) onto quartz and dental enamel with and without a salivary conditioning film, (iii) in a parallel plate (PP) and stagnation point (SP) flow chamber and at common Peclet numbers are com

  5. Treatment Experience of Acne by the Methods of Eliminating Stagnation and Anthracoma%散结消痈治疗痤疮经验

    Institute of Scientific and Technical Information of China (English)

    周宝宽; 周探

    2012-01-01

    Objective :To summarize treatment experience of acne by the. Methods of eliminating stagnation and anthracoma, and the decoctions of Miraculous decoction for regional infection, Lianqiao Baidu Powder, Wuwei Xiaodu Decoction, Simiao Yong'an decoction. Methods : Discuss principles, methods, formulas and medicinals of hypomnesia caused by sexual overindulgence based on medical records. Result: Acne with lung meridian wind-heat, toxic heat stagnanl was treated by Miraculous decoction for regional infection; acne with wind heat toxin attacking, toxic heat stagnation, qi stagnation blood stasis was treated by Lianqiao Baidu Powder; acne with lung meridian wind-heat, burn infection stagnation was treated by Wuwei Xiaodu Decoction;acne with toxic he.at flourishing and obstructing meridian and vessels was treated with Simiao Yong'an Decoction. Those methods and decoction show a better therapeutic effect on acne. Conclusions : Methods of eliminating stagnation and anthracoma have a good effect on acne.%目的:总结仙方活命饮、连翘败毒散、五味消毒饮、四妙勇安汤四方散结消痈治疗痤疮经验.方法:以医案形式,融理、法、方、药为一体进行阐述.结果:仙方活命饮加减治疗肺经风热、热毒壅滞型痤疮;连翘败毒散治疗风热毒邪上攻、热毒壅结、气血瘀滞型痤疮;五味消毒饮治疗肺经风热、火毒结聚型痤疮;四妙勇安汤治疗热毒炽盛、瘀阻经脉型痤疮,均取得满意疗效.结论:散结消痈治疗痤疮,疗效满意.

  6. Effects of Gender, Mathematics Anxiety and Achievement Motivation on College Students’ Achievement in Mathematics

    OpenAIRE

    Ajogbeje Oke James; Borisade Fidelis Tunde; Aladesaye Charles Ademuyiwa; Ayodele Oludolapo Bolanle

    2013-01-01

    The urge to excel or perform maximally in mathematics varies from individual to individual because achievement motivation is often developed or learnt during socialization and learning experiences. The study examined the relationship between College of Education students’ achievement motivation and mathematics achievement, correlation coefficient between mathematics anxiety and college students’ achievement motivation as well as mathematics anxiety and mathematics achievement. The sample, 268...

  7. Has Athletic Performance Reached its Peak?

    OpenAIRE

    Berthelot, Geoffroy,; Sedeaud, Adrien; Marck, Adrien; Antero-Jacquemin, Juliana; Schipman, Julien; Saulière, Guillaume; Marc, Andy; Desgorces, François-Denis; Toussaint, Jean-François

    2015-01-01

    Limits to athletic performance have long been a topic of myth and debate. However, sport performance appears to have reached a state of stagnation in recent years, suggesting that the physical capabilities of humans and other athletic species, such as greyhounds and thoroughbreds, cannot progress indefinitely. Although the ultimate capabilities may be predictable, the exact path for the absolute maximal performance values remains difficult to assess and relies on technical innovations, sport ...

  8. Estimating achievement from fame

    OpenAIRE

    Simkin, M. V.; Roychowdhury, V. P.

    2009-01-01

    We report a method for estimating people's achievement based on their fame. Earlier we discovered (cond-mat/0310049) that fame of fighter pilot aces (measured as number of Google hits) grows exponentially with their achievement (number of victories). We hypothesize that the same functional relation between achievement and fame holds for other professions. This allows us to estimate achievement for professions where an unquestionable and universally accepted measure of achievement does not exi...

  9. Slab stagnation and buckling in the mantle transition zone: Rheology, phase transition, trench migration, and seismic structure

    Science.gov (United States)

    Bina, Craig; Cizkova, Hana

    2014-05-01

    observations better than a flat-lying slab (Zhang et al., 2013). Earthquake hypocentral distributions and focal mechanisms may provide clearer insights into slab buckling, as they appear to vary systematically across regions of slab stagnation (Fukao and Obayashi, 2013). Stress fields computed from our dynamical models may help to illuminate such observations. References: Bina, C.R., and H. Kawakatsu, Buoyancy, bending, and seismic visibility in deep slab stagnation, Phys. Earth Planet. Inter., 183, 330-340, 2010. Čížková, H., and C.R. Bina, Effects of mantle and subduction-interface rheologies on slab stagnation and trench rollback, Earth Planet. Sci. Lett., 379, 95-103, 2013. Fukao, Y., and M. Obayashi, Deepest hypocentral distributions associated with stagnant slabs and penetrated slabs, Fall Meeting Abstracts, AGU, DI14A-01, 2013. Li, Z.-H., and N.M. Ribe, Dynamics of free subduction from 3-D boundary element modeling, J. Geophys. Res., 117, B06408. Matthews, D.C., L. Zheng, and R.G. Gordon, Do trenches advance? Fall Meeting Abstracts, AGU, T43D-2682, 2013. Zhang, Y., Y. Wang, Y. Wu, C. Bina, Z. Jin, and S. Dong, Phase transitions of harzburgite and buckled slab under eastern China, Geochem. Geophys. Geosys., 14, 1182-1199, 2013.

  10. Hot spot formation and stagnation properties in simulations of direct-drive NIF implosions

    Science.gov (United States)

    Schmitt, Andrew J.; Obenschain, Stephen P.

    2016-05-01

    We investigate different proposed methods of increasing the hot spot energy and radius in inertial confinement fusion implosions. In particular, shock mistiming (preferentially heating the inner edge of the target's fuel) and increasing the initial vapor gas density are investigated as possible control mechanisms. We find that only the latter is effective in substantially increasing the hot spot energy and dimensions while achieving ignition. In all cases an increase in the hot spot energy is accompanied by a decrease in the hot spot energy density (pressure) and both the yield and the gain of the target drop substantially. 2D simulations of increased vapor density targets predict an increase in the robustness of the target with respect to surface perturbations but are accompanied by significant yield degradation.

  11. Achieving success: moving beyond the comfort level.

    Science.gov (United States)

    Manji, I

    1993-11-01

    Understanding the stages of growth, saturation and transition is the first step to setting meaningful career goals. While this concept is fairly new in dentistry, it is not new in other commercial enterprises. Business managers and owners have known for decades that growth stagnates after a period of time. At that point, a new infusion of energy and a reformation of the business's objectives and methods are needed to launch forward into the next phase of growth. Transition management in dentistry represents periods of growth that are followed by saturation and a comparatively rapid changeover to a new practice form. Saturation occurs when the clinical capacity of a practice is exceeded by the needs of a growing patient base. The key transitions in the career of a dentist are those from school to practising, and practising to retirement. A great number of dentists (due to low motivation, the comfort level or poor management skills) never reach the saturation point during their practising career. For these dentists, starting out and retirement are the only transitions that will ever apply to them. Dentists evaluating transition options must first identify which career stage they belong to since their objectives will be different at each stage. Dentists in the growth phase should focus on practice management and achieving saturation before attempting a transition. Since transitions like start-up, retirement, partnerships, associateships and buy-ins have pivotal roles in the life cycle of a practice, transitions must be managed carefully to achieve successful results.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Performative

    DEFF Research Database (Denmark)

    Sack-Nielsen, Torsten

    2015-01-01

    The article describes the potential of building skins being climate-adaptive. The principle of folding, and the relation between form and performance of facades are discussed here.......The article describes the potential of building skins being climate-adaptive. The principle of folding, and the relation between form and performance of facades are discussed here....

  13. Using 1D theory to understand 3D stagnation of a wire-array Z pinch in the absence of radiation

    Science.gov (United States)

    Yu, Edmund

    2015-11-01

    Many high-energy-density systems implode towards the axis of symmetry, where it collides on itself, forming a hot plasma. However, experiments show these imploding plasmas develop three-dimensional (3D) structures. As a result, the plasma cannot completely dissipate its kinetic energy at stagnation, instead retaining significant 3D flow. A useful tool for understanding the effects of this residual flow is 3D simulation, but the amount and complexity of information can be daunting. To address this problem, we explore the connection between 3D simulation and one-dimensional (1D) theory. Such a connection, if it exists, is mutually beneficial: 1D theory can provide a clear picture of the underlying dynamics of 3D stagnation. On the other hand, deviations between theory and simulation suggest how 1D theory must be modified to account for 3D effects. In this work, we focus on a 3D, magnetohydrodynamic simulation of a compact wire-array Z pinch. To provide a simpler background against which to test our ideas, we artificially turn off radiation during the stagnation phase. Examination of the initial accumulation of mass on axis reveals oblique collision between jets, shock accretion, and vortex formation. Despite evidence for shock-dominated stagnation, a 1D shockless stagnation solution is more appropriate for describing the global dynamics, in that it reproduces the increase of on-axis density with time. However, the 1D solution must be modified to account for 3D effects: the flows suggest enhanced thermal transport as well as centrifugal force. Upon reaching peak compression, the stagnation transitions to a second phase, in which the high-pressure core on axis expands outward into the remaining imploding plasma. During this phase, a 1D shock solution describes the growth of the shock accretion region, as well as the decrease of on-axis density with time. However, the effect of 3D flows is still present: the on-axis temperature does not cool during expansion, which

  14. 不同下属特性对领导者成就动机与领导绩效关系的调节作用%Variors Subordinates Affecting the Relationship Between Leaders' Achievement Motivation and Performance

    Institute of Scientific and Technical Information of China (English)

    郭丹

    2011-01-01

    In the light of the leadership trait theory based on situation,we select various subordinates as the main situation,and study the effect of the situation on the relationship between the leaders' achievement motivation and performance.achievement motivation have significant positive relation to leader's performance in prevalent situations.After considering the situation of subordinates,the aforementioned relations do vary to corresponding degree.%在基于情境的领导素质理论思想指导下,以领导素质中的成就动机为切入点,选取任何组织中都存在的重要情境———不同下属特性,研究该情境对领导者成就动机与领导绩效关系所起的调节作用。领导者成就动机在普遍意义下与领导绩效有显著正相关关系,在加入下属特性情境因素后,领导者动机和领导绩效间的相关关系受到不同程度的影响。

  15. Heat Transfer due to Magnetohydrodynamic Stagnation-Point Flow of a Power-Law Fluid towards a Stretching Surface in the Presence of Thermal Radiation and Suction/Injection

    OpenAIRE

    Tapas Ray Mahapatra; Sabyasachi Mondal; Dulal Pal

    2012-01-01

    An analysis is made on the study of two-dimensional MHD (magnetohydrodynamic) boundary-layer stagnation-point flow of an electrically conducting power-law fluid over a stretching surface when the surface is stretched in its own plane with a velocity proportional to the distance from the stagnation-point in the presence of thermal radiation and suction/injection. The paper examines heat transfer in the stagnation-point flow of a power-law fluid except when the ratio of the free stream velocity...

  16. Vorticity amplification near the stagnation point of landing gear wheels: effect of the orientation of the impinging vorticity

    Science.gov (United States)

    Gu, Mingyao; Feltham, Graham; Ekmekci, Alis

    2014-11-01

    When oncoming streams of weak vorticity aligned with the axle axis of a two-wheel landing gear impinge near the forward stagnation point of the wheels, a mechanism for vorticity collection, growth, amplification into discrete large-scale vortices, and shedding was formerly shown to exist. In the current study, the impinging vorticity streams are perpendicular to the axle axis, i.e. in a vertical orientation as opposed to the horizontal orientation before. Experiments are conducted in a recirculating water channel using hydrogen bubble visualization and particle image velocimetry at a Reynolds number of 32,500 (based on the wheel diameter). As with the horizontal orientation, vorticity collection and amplification are observed, but the large-scale vortices thus formed are stretched around the wheel circumference in contrast to being stretched around the wheel sides, as observed for the horizontal orientation. This flow behavior varies with the impingement location of the vorticity streams across the wheel width. Maximum vorticity amplification occurs at a critical impingement location and drastically alters the flow separation along the wheel circumference. In addition, the instantaneous vortical structures are identified and tracked using a Galilean-invariant criterion.

  17. Melting heat transfer effects on stagnation point flow of micropolar fluid saturated in porous medium with internal heat generation (absorption)

    Institute of Scientific and Technical Information of China (English)

    M.A.A.MAHMOUD; S.E.WAHEED

    2014-01-01

    The effect of melting heat transfer on the two dimensional boundary layer flow of a micropolar fluid near a stagnation point embedded in a porous medium in the presence of internal heat generation/absorption is investigated. The governing non-linear partial differential equations describing the problem are reduced to a system of non-linear ordinary differential equations using similarity transformations solved numerically using the Chebyshev spectral method. Numerical results for velocity, angular velocity and temperature profiles are shown graphically and discussed for different values of the inverse Darcy number, the heat generation/absorption parameter, and the melting parameter. The effects of the pertinent parameters on the local skin-friction coefficient, the wall couple stress, and the local Nusselt number are tabulated and discussed. The results show that the inverse Darcy number has the effect of enhancing both velocity and temperature and suppressing angular velocity. It is also found that the local skin-friction coefficient decreases, while the local Nusselt number increases as the melting parameter increases.

  18. MHD Stagnation-Point Flow of a Carreau Fluid and Heat Transfer in the Presence of Convective Boundary Conditions.

    Science.gov (United States)

    Khan, Masood; Hashim; Alshomrani, Ali Saleh

    2016-01-01

    In the present investigation we analyze the impact of magnetic field on the stagnation-point flow of a generalized Newtonian Carreau fluid. The convective surface boundary conditions are considered to investigate the thermal boundary layer. The leading partial differential equations of the current problem are altered to a set of ordinary differential equations by picking local similarity transformations. The developed non-linear ordinary differential equations are then numerically integrated via Runge-Kutta Fehlberg method after changing into initial value problems. This investigation explores that the momentum and thermal boundary layers are significantly influenced by various pertinent parameters like the Hartmann number M, velocity shear ratio parameter α, Weissenberg number We, power law index n, Biot number γ and Prandtl number Pr. The analysis further reveals that the fluid velocity as well as the skin friction is raised by the velocity shear ratio parameter. Moreover, strong values of the Hartmann number correspond to thinning of the momentum boundary layer thickness while quite the opposite is true for the thermal boundary layer thickness. Additionally, it is seen that the numerical computations are in splendid consent with previously reported studies. PMID:27322600

  19. A Clinical Study of Safflower Yellow Injection in Treating Coronary Heart Disease Angina Pectoris with Xin-Blood Stagnation Syndrome

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective: To evaluate the clinical effect and safety of Safflower Yellow injection (SYI) in treating coronary heart disease angina pectoris (CHD-AP) with Xin-blood stagnation syndrome (XBSS).Methods: Adopted was the multi-centered, randomized, positive parallel controlled method, 448 patients with CHD-AP-XBSS were enrolled and divided into two groups, 336 in the tested group treated with SYI and112 in the control group treated with Salvia injection by intravenous dripping once a day for 14 days, so as to observe the conditions of angina, electrocardiogram, and therapeutic effect on traditinal Chinese medicine(TCM) symptoms as well as the safety of the treatment. Results: The significantly effective rate and total effective rate in the tested group were 60.06% (194/323) and 91.02% (294/323) respectively; those in improvement of TCM symptoms were 40.18% (129/321) and 75.23% (243/323) respectively, which were better than those in the control group (P<0.01). Conclusion: SYI Injection is effective and safe in treating CHD-AP-XBSS.

  20. Are the yields of major cereal crops stagnating? Results from the newly developed high spatial resolution crop yield time series

    Science.gov (United States)

    Ray, D. K.; Ramankutty, N.; Foley, J. A.

    2011-12-01

    A variety of global scale studies that use crop yield time series for the last 50 years have remained constrained to using national level information due to the lack of high spatial resolution crop yield time series data. In this presentation we will unveil a new global crop yield data set for the 1961-2008 time period, at 5 min spatial resolution, and covering 174 crops. We developed this data by collecting national and sub-national harvested area and production information for individual crops. This new dataset can be used to answer questions related to global agriculture at a resolution and over a time period not previously possible. We have used this new dataset to address the question of whether the yields of the three important cereal crops -- maize, rice and wheat -- are stagnating as widely reported. Our results show that while in the older crop belts of the world yield improvements have slowed, a green revolution type of major yield increases in maize, rice and wheat are continuing in newly cultivated areas of the world.

  1. A Critical Pragmatism: Marcuse, Adorno, and Peirce on the Artificial Stagnation of Individual and Social Development in Advanced Industrial Societies

    Directory of Open Access Journals (Sweden)

    Clancy Smith

    2009-12-01

    Full Text Available This paper will analyze the effects advanced industrial societies have on individual and social development through the eyes of Marcuse’s One-Dimensional Man and the moral consequences of such artificial stagnation through Adorno’s lectures on The Problems of Moral Philosophy. Because such an investigation necessarily brings us into the realm of social psychology, we will turn to the social psychological tradition at the heart of American pragmatism, a target for critical theorists who are often antagonistic to the entire tradition. We will endeavor to advance two alternate readings of the work of C.S. Peirce, arguing that although one type of pragmatism may be justly attacked by critical theorists, there is another, I argue, more critical manifestation of pragmatic human development, that requires the type of autonomy-infused, open-ended development that Marcuse champions. Moreover, I will argue that Peirce’s seminal essay “The Fixation of Belief” anticipated many of Marcuse’s critiques of advanced industrial societies by nearly ninety years.

  2. Unsteady boundary layer flow of a micro-polar fluid near the rear stagnation point of a plane surface

    Energy Technology Data Exchange (ETDEWEB)

    Lok, Yian Yian [Academic Service Center, Kolej Universiti Teknikal Kebangsaan Malaysia, 75450 Ayer Keroh, Melaka (Malaysia); Amin, Norsarahaida [Department of Mathematics, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Pop, Ioan [Faculty of Mathematics, University of Cluj, R-3400, CP 253, Cluj (Romania)

    2003-11-01

    The growth of the boundary layer flow of a viscous and incompressible micro-polar fluid started impulsively from rest near the rear stagnation point of a two-dimensional plane surface is studied theoretically. The transformed non-similar boundary-layer equations are solved numerically using a very efficient finite-difference method known as Keller-box method. This method may present well-behaved solutions for the transient (small time) solution up to the separation boundary layer flow. Numerical results are given for the reduced velocity and micro-rotation profiles, as well as for the skin friction coefficient when the material parameter K takes the values K=0 (Newtonian fluid), 0.5, 1, 1.1, 1.5, 2, 2.5 and 3 with the boundary condition for micro-rotation n=0 (strong concentration of microelements) and n=1/2 (weak concentration of microelements), respectively. Important features of these flow characteristics are shown on graphs and in tables. (authors)

  3. Unsteady mixed convection flow of a micro-polar fluid near the stagnation point on a vertical surface

    Energy Technology Data Exchange (ETDEWEB)

    Lok, Y.Y. [Center for Academic Services, Kolej Universiti Teknikal Kebangsaan Malaysia, 75450 Ayer Keroh, Melaka (Malaysia); Amin, N. [Department of Mathematics, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Pop, I. [Faculty of Mathematics, University of Cluj, R-3400 Cluj, CP 253 (Romania)

    2006-12-15

    The unsteady mixed convection boundary-layer flow of a micro-polar fluid near the region of the stagnation point on a double-infinite vertical flat plate is studied. It is assumed that the unsteadiness is caused by the impulsive motion of the free stream velocity and by sudden increase or sudden decrease in the surface temperature from the uniform ambient temperature. The problem is reduced to a system of non-dimensional partial differential equations, which is solved numerically using the Keller-box method. This method may present well-behaved solutions for the transient (small time) solution and those of the steady-state flow (large time) solution. It was found that there is a smooth transition from the small-time solution (initial unsteady-state flow) to the large-time solution (final steady-state flow). Further, it is shown that for both assisting and opposing cases and a fixed value of the Prandtl number, the reduced steady-state skin friction and the steady-state heat transfer from the wall (or Nusselt number) decrease with the increase of the material parameter. On the other hand, it is shown that with the increase of the Prandtl number and a fixed value of the material parameter, the reduced steady-state skin friction decreases when the flow is assisting and it increases when the flow is opposing. (author)

  4. MHD Stagnation-Point Flow of a Carreau Fluid and Heat Transfer in the Presence of Convective Boundary Conditions.

    Science.gov (United States)

    Khan, Masood; Hashim; Alshomrani, Ali Saleh

    2016-01-01

    In the present investigation we analyze the impact of magnetic field on the stagnation-point flow of a generalized Newtonian Carreau fluid. The convective surface boundary conditions are considered to investigate the thermal boundary layer. The leading partial differential equations of the current problem are altered to a set of ordinary differential equations by picking local similarity transformations. The developed non-linear ordinary differential equations are then numerically integrated via Runge-Kutta Fehlberg method after changing into initial value problems. This investigation explores that the momentum and thermal boundary layers are significantly influenced by various pertinent parameters like the Hartmann number M, velocity shear ratio parameter α, Weissenberg number We, power law index n, Biot number γ and Prandtl number Pr. The analysis further reveals that the fluid velocity as well as the skin friction is raised by the velocity shear ratio parameter. Moreover, strong values of the Hartmann number correspond to thinning of the momentum boundary layer thickness while quite the opposite is true for the thermal boundary layer thickness. Additionally, it is seen that the numerical computations are in splendid consent with previously reported studies.

  5. MHD Stagnation-Point Flow of a Carreau Fluid and Heat Transfer in the Presence of Convective Boundary Conditions.

    Directory of Open Access Journals (Sweden)

    Masood Khan

    Full Text Available In the present investigation we analyze the impact of magnetic field on the stagnation-point flow of a generalized Newtonian Carreau fluid. The convective surface boundary conditions are considered to investigate the thermal boundary layer. The leading partial differential equations of the current problem are altered to a set of ordinary differential equations by picking local similarity transformations. The developed non-linear ordinary differential equations are then numerically integrated via Runge-Kutta Fehlberg method after changing into initial value problems. This investigation explores that the momentum and thermal boundary layers are significantly influenced by various pertinent parameters like the Hartmann number M, velocity shear ratio parameter α, Weissenberg number We, power law index n, Biot number γ and Prandtl number Pr. The analysis further reveals that the fluid velocity as well as the skin friction is raised by the velocity shear ratio parameter. Moreover, strong values of the Hartmann number correspond to thinning of the momentum boundary layer thickness while quite the opposite is true for the thermal boundary layer thickness. Additionally, it is seen that the numerical computations are in splendid consent with previously reported studies.

  6. Stagnation-point Flow and Heat Transfer of a Nanofluid Adjacent to Linearly Stretching/Shrinking Sheet: A Numerical Study

    Directory of Open Access Journals (Sweden)

    Sadegh Khalili

    2014-01-01

    Full Text Available In this study, the steady stagnation point flow and heat transfer of three different types of nanofluid over a linearly shrinking/stretching sheet is investigated numerically. A similarity transformation is used to reduce the governing system of partial differential equations to a set of nonlinear ordinary differential equations which are then solved numerically using the fourth-order Runge-Kutta method with shooting technique. The effects of the governing parameters on the nanofluid flow and heat transfer characteristics are analyzed and discussed. Numerical results for the local Nusselt number, skin friction coefficient, velocity profiles and temperature profiles are presented for different values of the solid volume fraction (&empty and for three different types of nanoparticles (Cu, Al2O3 and TiO2 in stretching or shrinking cases. It is found that the skin friction coefficient and the heat transfer rate at the surface are highest for Cu-water nanofluid compared to the Al2O3-water and Al2O3 Ti2 -water nanofluids. Furthermore, it was seen that the effect of the solid volume fraction of nanoparticles on the heat transfer and fluid flow characteristics is more important compared to the type of the nanoparticles.

  7. Dual solutions of MHD stagnation point flow and heat transfer over a stretching/shrinking sheet with generalized slip condition

    Institute of Scientific and Technical Information of China (English)

    ABBAS Zaheer; MASOOD Tahmina; OLANREWAJU Philip Oladapo

    2015-01-01

    An analysis was made to study the steady momentum and heat transfer characteristics of a viscous electrically conducting fluid near a stagnation point due to a stretching/shrinking sheet in the presence of a transverse magnetic field and generalized slip condition. Two flow problems corresponding to the planar and axisymmetric stretching/shrinking sheet were considered. By means of similarity transformations, the obtained resultant nonlinear ordinary differential equations were solved numerically using a shooting method for dual solutions of velocity and temperature profiles. Some important physical features of the flow and heat transfer in terms of the fluid velocity, the temperature distribution, the skin friction coefficient and the local Nusselt number for various values of the controlling governing parameters like velocity slip parameter, critical shear rate, magnetic field, ratio of stretching/shrinking rate to external flow rate and Prandtl number were analyzed and discussed. An increase of the critical shear rate decreases the fluid velocity whereas the local Nusselt number increases. The comparison of the present numerical results with the existing literature in a limiting case is given and found to be in an excellent agreement.

  8. "The Crisis of Finance-dominated Capitalism in the Euro Area: Deficiencies in the Economic Policy Architecture and Deflationary Stagnation Policies"

    OpenAIRE

    Hein, Eckhard

    2012-01-01

    In this paper the euro crisis is interpreted as the latest episode in the crisis of finance-dominated capitalism. For 11 initial Euro area countries, the major features of finance-dominated capitalism are analyzed; specifically, the increasing inequality of income distribution and the rising imbalances of current accounts. Against this background, the euro crisis and the economic policy reactions of European governments and institutions are examined. It is shown that deflationary stagnation p...

  9. Variation character of stagnation point heat flux for hypersonic pointed bodies from continuum to rarefied flow states and its bridge function study

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This paper is a research on the variation character of stagnation point heat flux for hypersonic pointed bodies from continuum to rarefied flow states by using theoretical analysis and numerical simulation methods. The newly developed near space hypersonic cruise vehicles have sharp noses and wingtips,which desires exact and relatively simple methods to estimate the stagnation point heat flux. With the decrease of the curvature radius of the leading edge,the flow becomes rarefied gradually,and viscous interaction effects and rarefied gas effects come forth successively,which results in that the classical Fay-Riddell equation under continuum hypothesis will become invalid and the variation of stagnation point heat flux is characterized by a new trend. The heat flux approaches the free molecular flow limit instead of an infinite value when the curvature radius of the leading edge tends to 0. The physical mechanism behind this phenomenon remains in need of theoretical study. Firstly,due to the fact that the whole flow regime can be described by Boltzmann equation,the continuum and rarefied flow are analyzed under a uniform framework. A relationship is established between the molecular collision insufficiency in rarefied flow and the failure of Fourier’s heat conduction law along with the increasing significance of the nonlinear heat flux. Then based on an inspiration drew from Burnett approximation,control factors are grasped and a specific heat flux expression containing the nonlinear term is designed in the stagnation region of hypersonic leading edge. Together with flow pattern analysis,the ratio of nonlinear to linear heat flux Wr is theoretically obtained as a parameter which reflects the influence of nonlinear factors,i.e. a criterion to classify the hypersonic rarefied flows. Ultimately,based on the characteristic parameter Wr,a bridge function with physical background is constructed,which predicts comparative reasonable results in coincidence well with DSMC

  10. Effects of Magnetic Field and Thermal Radiation on Stagnation Flow and Heat Transfer of a Power-Law Fluid over a Shrinking Sheet

    OpenAIRE

    Samir Kumar Nandy

    2013-01-01

    An analysis is made on the steady two-dimensional boundary layer magnetohydrodynamic (MHD) stagnation-point flow and radiative heat transfer of an electrically conducting power-law fluid over a shrinking sheet which is shrunk in its own plane with a velocity proportional to the distance from a fixed point. The similarity transformations are used to transform the boundary layer equations into a system of nonlinear ordinary differential equations which are then solved numerically using shooting...

  11. Achieving world class maintenance status

    Energy Technology Data Exchange (ETDEWEB)

    Tomlingson, P.D. [Paul D. Tomingson Associates (United States)

    2007-08-15

    The article written by a management consultant, discusses the art of successful planning and operation of maintenance in mines considering factors such as benchmaking, key performance indices (KPIs) and frequency of procedures which can help achieve 'world class maintenance'. 1 fig.

  12. Ant Colony Optimization Based Modified Termite Algorithm (MTA with Efficient Stagnation Avoidance Strategy for MANETs

    Directory of Open Access Journals (Sweden)

    Sharvani G S

    2012-10-01

    Full Text Available Designing an effective load balancing algorithm is difficult due to Dynamic topology of MANET. Toaddress the problem, a load balancing routing algorithm namely Modified Termite Algorithm (MTA hasbeen developed based on ant’s food foraging behavior. Stability of the link is determined based on nodestability factor ‘’. The stability factor “ “of the node is the ratio defined between the “hello sent” and“hello replied” by a node to its neighbors. This also indicates the link stability in relation to other pathstowards the destination. A higher ratio of “” indicates that the neighbor node is more stable. Using thisconcept pheromone evaporation for the stable node is fine tuned such that if the ratio “” is more, theevaporation is slow and if “” is less the evaporation is faster. This leads to decreasing of the pheromonecontent in an optimal path which may result in congestion. These paths can be avoided using efficientevaporation technique. The MTA developed by adopting efficient pheromone evaporation technique willaddress the load balancing problems and expected to enhance the performance of the network in terms ofthroughput, and reduces End-to-end delay and Routing overheads

  13. Efficient Stagnation Avoidance for Manets with Local Repair Strategy Using ant Colony Optimization

    Directory of Open Access Journals (Sweden)

    Sharvani G S

    2012-10-01

    Full Text Available Wireless networks such as Mobile AdHoc Networks (MANETs have many advantages compared to wired networks. In MANETs the communication is not limited to a certain geometrical region. Swarm Intelligence based ACO algorithms provide interesting solutions to network routing problems. ACO based routing in MANETs will enhance the reliability and efficient packet delivery. They help in reducing control overhead due to their inherent scalable feature. The similarity between ant and nodes, colony and Wireless network helps to use ACO based routing in MANETs. The Termite Algorithms contains several tunable parameters and methods to automate the selection of optimal routes for different network conditions. However, Termite doesn’t contain methods for determination of QoS, Route Maintenance; Load balancing etc. The present work focuses on development of an efficient routing algorithm “Modified Termite algorithms” (MTA for MANETs. The MTA developed by adopting efficient pheromone evaporation technique will address to load balancing problems. By including QoS, efficient route maintenance, local repair strategy by prediction of node failures, the MTA is expected to enhance the performance of the network in terms of throughput, and reduction of End-to-end delay and routing overheads. The results of the analysis are presented in the paper.

  14. Metacognition, achievement goals, study strategies and academic achievement: pathways to achievement

    NARCIS (Netherlands)

    A. Vrugt; F.J. Oort

    2008-01-01

    The purpose of this research was to develop and test a model of effective selfregulated learning. Based on effort expenditure we discerned effective self-regulators and less effective self-regulators. The model comprised achievement goals (mastery, performance-approach and -avoidance goals), metacog

  15. 基于大数据技术的配电网抢修驻点优化方法%Optimization Method of Repair the Stagnation Point Distribution Based on Big Data Analysis Method

    Institute of Scientific and Technical Information of China (English)

    陆如; 范宏; 周献远

    2015-01-01

    Emergency repair is an important task in the operation of distribution network,for which the scientific and efficient management and implementation method is vital to improve reliability and service quality of distribution network. A method based on Hadoop analysis method is proposed to solve the optimization problem of distribution network emergency repair stagnation points.The factors that affect the efficiency of distribution network emergency repair is analyzed comprehensively,optimization model for emergency repair stagnation point is built up,and the data mining technique for processing big data is introduced to enhance the efficiency of model analysis.In addition,the reasonable and effective allocation of emergency repair resources is achieved by quick and accurate estimation of fault time and fault point and comprehensive analysis and location of distribution network emergency repair points and states,thus improving the serve quantity and efficiency of emergency repair.%配电网故障抢修是配电网运行的重要工作,科学高效的抢修管理和实施方法对提高配电网供电可靠性和配电网服务质量意义重大.提出了基于Hadoop处理技术的大数据解决方法处理配电网抢修驻点优化问题;全面分析了影响配电网抢修效率的各个因素;建立了配电网抢修驻点优化模型;引入了处理大数据的数据挖掘技术以提高模型分析的效率.此外,通过对配电网抢修点和抢修态进行综合分析与定位,对电网故障发生时间和故障位置的准确快速判断,实现合理有效调配抢修资源,从而提高配电网故障抢修工作的服务质量和效率.

  16. Clinical Research of the Formula for Removing Stagnation and Cleary Heat in the Improvements of Pancreas Function%开郁清热方改善胰岛功能的临床研究

    Institute of Scientific and Technical Information of China (English)

    宋军; 仝小林; 赵林华; 姬航宇

    2012-01-01

    目的 验证开郁清热方改善胰岛功能的临床疗效.方法 选取仝小林教授于广安门医院门诊诊治的2型糖尿病病历116例,所有患者辨证均属于肝郁胃热证,给予中药开郁清热方治疗,于治疗前、治疗后3个月、6个月、1年、1年半、2年分别记录其空腹血糖(FPG)、餐后2 h血糖(2 h PG)、胰岛素等检查指标,并根据公式计算患者胰岛功能指数(HOMA-β),运用统计软件SPSS16.0对数据进行分析.结果 治疗后各组空腹血糖、餐后2 h血糖均较治疗前有明显下降(P<0.05),而治疗后各组间空腹血糖、餐后2 h血糖比较,差异无统计学意义(P>0.05);HOMA-β均有一定程度的下降,但治疗前、治疗后比较,差异无统计学意义(P>0.05).结论 开郁清热方具有一定的胰岛功能保护作用.%Objective To verify the clinical efficacy of the formula for removing stasis and clearing heat in the improvements of pancreas function. Methods 116 cases of diabetes type 2 treated with Prof. TONG Xiao - lin were selected from the clinic of Guanganmen Hospital. All the cases were differentiated as liver stagnation and stomach heat pattern and were treated with the formula for removing stagnation and clearing heat. Before treatment,in 3 months,6 months, 1 year,l. 5 years and 2 years after treatment,the levels of FPG, 2hPG, insulin and the other indexes were recorded separately. HOMA - ? Value was calculated with a formula and the data were analyzed with SPSS16. 0 software. Results The levels of FPG and 2hPG after treatment were reduced apparently as compared with those before treatment in each group( P 0.05 ). HOMA - β value was reduced to a certain extent,but without statistical significance before and after treatment P > 0. 05 ). Conclusion The formula for removing stagnation and clearing heat achieves a certain protection of pancreas function.

  17. Determinants of Student Achievement in Turkey

    OpenAIRE

    Gokce Uysal; M. Alper Dincer

    2009-01-01

    Recent achievement test results show that Turkish students have been performing poorly compared to students from other countries. Using data from the PISA 2006 survey, we aim to measure the determinants of student achievement in Turkey. We find that the program type the student is enrolled in affects student achievement significantly. However, this effect may partially be biased by past academic achievement. In line with the previous literature, our results also indicate that school resources...

  18. Breathtaking or stagnation?

    DEFF Research Database (Denmark)

    Sauer, Johannes; Graversen, Jesper Tranbjerg; Park, Tim

    2006-01-01

    efficiency on farm level is analyzed by considering also curvature consistency. The total change in productivity for the reference period is measured by using the Malmquist total factor productivity index approach based on a time trends as well as a general index model specification. Input specific bias...... in technical change as well as a general index model specification. Input specific bias in technical change as well elasticities of input substitution are analyzed. Factors for the development of technical change and the change in efficiency over time are investigated by applying a bootstrapped ITSUR...... techniques. Finally we try to conclude on the significance of subsidies for promoting long term growth in organic production by estimating a bootstrapped bivariate probit model with respect to factors influencing the probability of organic market exit. The results revealed significant difference...

  19. DIDACTICS: DEVELOPMENT OR STAGNATION?

    Directory of Open Access Journals (Sweden)

    I. P. Smirnov

    2016-01-01

    Full Text Available The aim of the paper – the detailed analysis of the monograph «Contents and Structure of Regularities of Process of Training (Theory and Experiment» which is written by the corresponding member of the Russian Academy of Education (RAE, Doctor of pedagogical sciences, Professor I. I. Logvinov. The book was included into a series «Basic researches of institute of the theory and history of pedagogics of the Russian Academy of Education. Proceedings 2008–2012».The review of the monograph of I. I. Logvinov has become a reason for reflections of the author of the present publication about actual, most burning issues of a modern Russian educational system: on the status of pedagogics in modern domestic science; evolutions of didactic knowledge and its typology; quality of dissertation researches and emasculation in scientific pedagogical concepts of the fundamental bases; ideologization of didactics and a role of the state in this process.Sorting basic thesis of I. I. Logvinov’s work, in something agreeing, and in something arguing with the scientist, the author of article claims that it is a serious and necessary work where the extremely important questions concerning the most painful points of the Russian pedagogical science and a condition of our education in general are brought up.

  20. College Achievement and Earnings

    OpenAIRE

    Gemus, Jonathan

    2010-01-01

    I study the size and sources of the monetary return to college achievement as measured by cumulative Grade Point Average (GPA). I first present evidence that the return to achievement is large and statistically significant. I find, however, that this masks variation in the return across different groups of people. In particular, there is no relationship between GPA and earnings for graduate degree holders but a large and positive relationship for people without a graduate degree. To reconcile...

  1. Migrants and educational achievement gaps

    OpenAIRE

    Entorf, Horst

    2015-01-01

    As global migration flows increase, so do the number of migrant students in host country schools. Yet migrants' achievement scores lag well behind those of their native-born schoolmates. Performance gaps are explained largely by differences in migrant parents' socio-economic background, cultural capital, and language skills. Education policy needs to focus on language teaching, parental involvement, diversity training, and beneficial social interaction between immigrant and native-born popula...

  2. Treating Impotence from Asthenia and Liver stagnation%从虚劳肝瘀论治阳痿

    Institute of Scientific and Technical Information of China (English)

    王国强

    2014-01-01

    阳痿是指成年男子性交时,由于阴茎痿软不举,或举而不坚,或坚而不久,无法进行正常性生活的病证。中医对阳痿的认识已有3千年的历史,《素问•痿论》中又称“宗筋弛纵”和“筋萎”,“思想无穷,所愿不得,发为筋痿”。《灵枢•邪气脏腑病形》篇称阳痿为“阴痿”。《类证治裁》说“伤于内则阳不起,故阳之痿”。《伤寒杂病论》将阳痿列至虚劳篇,“男子平人,脉大为劳,极虚亦为劳”。总结历代医家思想,笔者认为应从虚劳、从肝和从瘀三个方面论治阳痿。%Impotence is an adult man’s sexual disease in which his penis fails to get hard or stay hard during the intercourse. The understanding of impotence in TCM has a history of 3000 years. In Treatise of Atrophy of Plain Question, impotence was called “loose tendon”or“tendon atrophy”,“much desire with little realization will cause impotence”. In Viscera Disease Pathogen of Miraculous Pivot, impotence was called “Yinwei”. In Leizheng Zhicai, it is said that internal damage can cause impotence. In Treatise on Febrile and Miscellaneous Diseases, impotence was listed in asthenia volume. It is said a man with big pulse is considered as atrophy and severe weakness is also atrophy. From the summary of the medical theory of doctors in various dynasty, the writer thinks impotence should be treated from the aspects of atrophy, liver and stagnation.

  3. Biological nitrate transport in sediments on the Peruvian margin mitigates benthic sulfide emissions and drives pelagic N loss during stagnation events

    Science.gov (United States)

    Dale, A. W.; Sommer, S.; Lomnitz, U.; Bourbonnais, A.; Wallmann, K.

    2016-06-01

    Benthic N cycling in the Peruvian oxygen minimum zone (OMZ) was investigated at ten stations along 12 °S from the middle shelf (74 m) to the upper slope (1024 m) using in situ flux measurements, sediment biogeochemistry and modeling. Middle shelf sediments were covered by mats of the filamentous bacteria Thioploca spp. and contained a large 'hidden' pool of nitrate that was not detectable in the porewater. This was attributed to a biological nitrate reservoir stored within the bacteria to oxidize sulfide during 'dissimilatory nitrate reduction to ammonium' (DNRA). The extremely high rates of DNRA on the shelf (15.6 mmol m-2 d-1 of N), determined using an empirical steady-state model, could easily supply all the ammonium requirements for anammox in the water column. The model further showed that denitrification by foraminifera may account for 90% of N2 production at the lower edge of the OMZ. At the time of sampling, dissolved oxygen was below detection limit down to 400 m and the water body overlying the shelf had stagnated, resulting in complete depletion of nitrate and nitrite. A decrease in the biological nitrate pool was observed on the shelf during fieldwork concomitant with a rise in porewater sulfide levels in surface sediments to 2 mM. Using a non-steady state model to simulate this natural anoxia experiment, these observations were shown to be consistent with Thioploca surviving on a dwindling intracellular nitrate reservoir to survive the stagnation period. The model shows that sediments hosting Thioploca are able to maintain high ammonium fluxes for many weeks following stagnation, potentially sustaining pelagic N loss by anammox. In contrast, sulfide emissions remain low, reducing the economic risk to the Peruvian fishery by toxic sulfide plume development.

  4. Two Quality of Higher Vocational College Graduates.Academic Achievement and Workplace Performance%高职院校毕业生的两种质量:学业成就以及职场表现

    Institute of Scientific and Technical Information of China (English)

    庄西真

    2012-01-01

    According to the view of the higher occupation education is a kind of training skilled personnel educa- tion, the lack of skilled talents and the higher occupation education expansion between contrast analysis, this arti- cle put forward the skill talent has its own development law of conclusion. On this basis, the article according to the higher occupation college graduates' dual identity judgment, then put forward the higher occupation college graduates' academic achievement and job performance of two kinds of quality.%根据高等职业教育是一种培养技能型人才的教育的普遍观点,通过技能型人才短缺和高等职业教育规模扩张之间反差的分析,提出技能型人才有自己的成长规律的结论。在此基础上,根据高等职业院校毕业生的双重身份特点,提出高等职业院校毕业生有学业成就和职场表现两种质量的结论。

  5. Performance assessment of a cavity ring-down laser spectrometer: achieving better precision and accuracy in the measurement of δ18O and δ2H in liquid water samples

    International Nuclear Information System (INIS)

    The development of new isotopic laser-based analyzers currently represents a clear alternative to conventional isotope ratio mass spectrometers. However, this analytical technique also suffers some disadvantages such as the memory effect, problems related to the overall stability of the equipment and other issues associated with the injection system, essentially regarding the syringe's longevity. This paper aims to minimize these disadvantages in order to increase the overall performance, in terms of precision and accuracy, of these kinds of analyzers. The main results of the experiments carried out in this paper have shown that: (i) the minimum number of discarded injections needed to eliminate the memory effect can be determined just considering the expected isotopic signature difference between two consecutive samples; (ii) both accuracy and precision of the isotopic measurements increase with increasing injection volume up to 2.1–2.2 µL; (iii) it is possible to extend the syringe lifetime by almost a factor of 6 by using n-methyl 2-pyrrolidone as a lubricant. Besides, it has been concluded that, by using the appropriate procedure, the main disadvantages associated with CRDS laser spectroscopy analyzers can be minimized, achieving measurement accuracy and precision of the order of ±0.05 ‰ for δ18O and ±0.3 ‰ for δ2H. (paper)

  6. Simultaneous Effects of MHD and Thermal Radiation on the Mixed Convection Stagnation-Point Flow of a Power-Law Fluid

    Institute of Scientific and Technical Information of China (English)

    T. Hayat; M. Mustafa; S. Obaidat

    2011-01-01

    Magnetohydrodynamic (MHD) mixed convection stagnation-point flow and heat transfer of power-law fluids towards a stretching surface is investigated.The homotopy analysis method (HAM) is used in finding the series solution for a nonlinear problem.Closed form solutions for velocity and temperature fields are presented in the limiting cases.Graphical results are shown.It is found that velocity and temperature are decreasing functions of power law index.Numerical computations for shear stress coefficient and local Nusselt number are reported.The present results are also compared with the existing numerical solution in a limiting sense.

  7. Method for exciting a gas dynamic CO/sub 2/ laser at high stagnation temperatures and apparatus for practical application. Verfahren zum Anregen eines gasdynamischen CO/sub 2/-Lasers bei hohen Stagnationstemperaturen und Anordnung zur Durchfuehrung des Verfahrens

    Energy Technology Data Exchange (ETDEWEB)

    Born, G.; Hermansdorfer, H.; Sepp, G.; Grosch, G.

    1981-03-26

    A method for exciting a gas dynamic CO/sub 2/ laser, especially at high stagnation temperatures above 2500 K and at a combustion chamber pressure above 50 bar, is described. A liquid fuel (e.g. C/sub 6/H/sub 6/, C/sub 2/N/sub 2/, C/sub 7/H/sub 5/N, C/sub 5/H/sub 5/N) and a liquid oxidizer (e.g. N/sub 2/O, NO, N/sub 2/O/sub 4/) are injected into the combustion chamber at these operating parameters and the produced laser gas is caused to flow through a Laval nozzle into a resonator. The flow cross sectional area of the Laval nozzle adjacent to the resonator is at least 100 times larger than the flow cross sectional area adjacent to the nozzle neck facing the combustion chamber. The flow of the laser gas through this nozzle cools the gas to about 300 K, whereby an inversion state is produced. The laser for performing this type of operation has a combustion chamber connected through the above mentioned nozzle to a resonator which in turn is connected to a diffuser. A tank for liquid fuel and a tank for a liquid oxidizer are connected to the respective injection nozzles of the combustion chamber, whereby the respective conduits preferably extend through cooling jackets of the combustion chamber of the diffuser.

  8. Intelligence and Educational Achievement

    Science.gov (United States)

    Deary, Ian J.; Strand, Steve; Smith, Pauline; Fernandes, Cres

    2007-01-01

    This 5-year prospective longitudinal study of 70,000+ English children examined the association between psychometric intelligence at age 11 years and educational achievement in national examinations in 25 academic subjects at age 16. The correlation between a latent intelligence trait (Spearman's "g"from CAT2E) and a latent trait of educational…

  9. Setting and Achieving Objectives.

    Science.gov (United States)

    Knoop, Robert

    1986-01-01

    Provides basic guidelines which school officials and school boards may find helpful in negotiating, establishing, and managing objectives. Discusses characteristics of good objectives, specific and directional objectives, multiple objectives, participation in setting objectives, feedback on goal process and achievement, and managing a school…

  10. Three-dimensional magnetohydrodynamics axisymmetric stagnation flow and heat transfer due to an axisymmetric shrinking/stretching sheet with viscous dissipation and heat source/sink

    International Nuclear Information System (INIS)

    The present work is concerned with the effects of viscous dissipation and heat source/sink on a three-dimensional magnetohydrodynamic boundary layer axisymmetric stagnation flow, and the heat transfer of an electrically conducting fluid over a sheet, which shrinks or stretches axisymmetrically in its own plane where the line of the symmetry of the stagnation flow and that of the shrinking (stretching) sheet are, in general, not aligned. The governing equations are transformed into ordinary differential equations by using suitable similarity transformations and then solved numerically by a shooting technique. This investigation explores the conditions of the non-existence, existence and uniqueness of the solutions of the similar equations numerically. It is noted that the range of the velocity ratio parameter, where the similarity solution exists, is increased with the increase of the value of the magnetic parameter. Furthermore, the study reveals that the non-alignment function affects the shrinking sheet more than the stretching sheet. In addition, the numerical results of the velocity profile, temperature profile, skin-friction coefficient, and rate of heat transfer at the sheet are discussed in detail with different parameters. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  11. A Clinical Study on the Treatment of Chronic Pelvic Inflammation of Qi-stagnation with Blood Stasis Syndrome by Penyanqing Capsule (盆炎清胶囊)

    Institute of Scientific and Technical Information of China (English)

    SHEN Bi-qiong; SITU Yi; HUANG Jian-ling; SU Xiao-mei; HE Wei-tang; ZHANG Mao-wei; CHEN Qu-bo

    2005-01-01

    Objective: To observe the clinical efficacy of Penyanqing Capsule (盆炎清胶囊, PYQC) in treating pelvic inflammation of Qi-stagnation with blood stasis syndrome. Methods: The randomized, single blinded, parallel positive drug controlled method was adopted, with 82 patients assigned into two groups by envelop method. The 42 patients in the treated group received PYQC 3 times a day, 4 capsules each time taken orally; the 40 patients in the control group were given orally Fuyankang tablets (妇炎康片, FYKT) 3 times a day, 6 tablets each time. The therapeutic course for both groups was 2 months, and 2 courses of treatment were given successively to observe the comprehensive effect, changes of symptoms and signs before and after treatment. The effects of PYQC on hemorrheological character in part of the patients and on the pathogenetic chlamydia and mycoplasma were also observed. Results: The total effective rate in the treated group was 83.3 %, which was insignificantly different from that in the control group ( 77.5 %, P > 0.05 ).However, PYQC could significantly lower the hemorrheologic indexes in patients and showed definite influence on the pathogenetic chlamydia and mycoplasma. Conclusion: PYQC has good therapeutic effect in treating chronic pelvic inflammation of Qi-stagnation with blood stasis syndrome, and showed definite effect on chlamydia and mycoplasma.

  12. Achievement Goals, Learning Strategies and Language Achievement among Peruvian High School Students

    Directory of Open Access Journals (Sweden)

    Lennia Matos

    2007-05-01

    Full Text Available We used an achievement goal framework to study the role of motivation in the academic context of a Peruvian sample of 8th to 10th grade high school students (N = 1505. The purpose of this cross-sectional study was to examine the relationship between students' achievement goals, their use of learning strategies and their academic achievement. Multiple Hierarchical Regressions Analyses identified, as predicted, positive effects of mastery goals, including more use of learning strategies and higher academic achievement, and negative effects of performance avoidance goals, including lower academic achievement. Mixed results were found for pursuing performance approach goals, which predicted a greater use of learning strategies, but were unrelated to academic achievement. The present findings support the external validity of achievement goal theory in a sample of students from a culture that is understudied in the achievement goal literature in particular and the motivational literature in general.

  13. Teaching for Successful Intelligence Raises School Achievement.

    Science.gov (United States)

    Sternberg, Robert J.; Torff, Bruce; Grigorenko, Elena

    1998-01-01

    A "successful intelligence" intervention improved school achievement for a group of 225 ethnically diverse third-graders, both on performance assessments measuring analytical, creative, and practical achievements and on conventional multiple-choice memory assessments. Teaching for triarchic thinking facilitates factual recall, because learning…

  14. Achieveing Organizational Excellence Through

    Directory of Open Access Journals (Sweden)

    Mehdi Abzari

    2009-04-01

    Full Text Available AbstractToday, In order to create motivation and desirable behavior in employees, to obtain organizational goals,to increase human resources productivity and finally to achieve organizational excellence, top managers oforganizations apply new and effective strategies. One of these strategies to achieve organizational excellenceis creating desirable corporate culture. This research has been conducted to identify the path to reachorganizational excellence by creating corporate culture according to the standards and criteria oforganizational excellence. The result of the so-called research is this paper in which researchers foundtwenty models and components of corporate culture and based on the Industry, organizational goals andEFQM model developed a model called "The Eskimo model of Culture-Excellence". The method of theresearch is survey and field study and the questionnaires were distributed among 116 managers andemployees. To assess the reliability of questionnaires, Cronbach alpha was measured to be 95% in the idealsituation and 0/97 in the current situation. Systematic sampling was done and in the pre-test stage 45questionnaires were distributed. A comparison between the current and the ideal corporate culture based onthe views of managers and employees was done and finally it has been concluded that corporate culture isthe main factor to facilitate corporate excellence and success in order to achieve organizational effectiveness.The contribution of this paper is that it proposes a localized –applicable model of corporate excellencethrough reinforcing corporate culture.

  15. Identifying learning techniques among high achievers

    OpenAIRE

    Shanmukananda P; L. Padma

    2013-01-01

    Background: In every college, it is noticed that in spite of being exposed to the same teaching modalities and adopting seemingly similar strategies, some students perform much better than their peers. This can be evaluated in the form of better academic performance in the internal assessments they undertake. This project is an endeavor to identify the learning techniques among high achievers which they employ to outperform others. We can also suggest the same to the medium and low achievers ...

  16. [The Colombian healthcare system: 20 years of achievements and problems].

    Science.gov (United States)

    Calderón, Carlos Alberto Agudelo; Botero, Jaime Cardona; Bolaños, Jesús Ortega; Martínez, Rocio Robledo

    2011-06-01

    An overview of some of the key processes and results of Colombia's National Health System is presented. A systematic review of the literature evaluating the quality of the evidence published in indexed journals and literature not published in journals was made. Health system financial resources have seen a sustained increase while spending on health has remained at around 8% of GNP. Coverage, measured by affiliation to contributory and subsidized regimes, is in the order of 92% of the total population. The Mandatory Health Plan, defining the benefits to which one has access, has been broadly maintained but has been hampered by mechanisms for making legal complaints, thereby leading to financial deficits. The health system has contributed towards improving the poorest sector's income, but inequalities persist due to the lack of universal coverage, differences in health plans and the system's expenditure according to the population's income. Advances made in the National Health System have been positive but universality has not been achieved and this has stagnated in matters regarding access to services and equality. PMID:21709979

  17. Achieving English Spoken Fluency

    Institute of Scientific and Technical Information of China (English)

    王鲜杰

    2000-01-01

    Language is first and foremost oral,spoken language,speaking skill is the most important one of the four skills(L,S,R,W)and also it is the most difficult one of the four skills. To have an all-round command of a language one must be able to speak and to understand the spoken language, it is not enough for a language learner only to have a good reading and writing skills. As Englisn language teachers, we need to focus on improving learners' English speaking skill to meet the need of our society and our country and provide learner some useful techniques to achieving their English spoken fluency. This paper focuses on the spoken how to improving learners speaking skill.

  18. Achieving diagnosis by consensus

    LENUS (Irish Health Repository)

    Kane, Bridget

    2009-08-01

    This paper provides an analysis of the collaborative work conducted at a multidisciplinary medical team meeting, where a patient’s definitive diagnosis is agreed, by consensus. The features that distinguish this process of diagnostic work by consensus are examined in depth. The current use of technology to support this collaborative activity is described, and experienced deficiencies are identified. Emphasis is placed on the visual and perceptual difficulty for individual specialities in making interpretations, and on how, through collaboration in discussion, definitive diagnosis is actually achieved. The challenge for providing adequate support for the multidisciplinary team at their meeting is outlined, given the multifaceted nature of the setting, i.e. patient management, educational, organizational and social functions, that need to be satisfied.

  19. Lie Group Analysis and Similarity Solutions for Mixed Convection Boundary Layers in the Stagnation-Point Flow toward a Stretching Vertical Sheet

    Directory of Open Access Journals (Sweden)

    Sarkhosh Seddighi Chaharborj

    2013-01-01

    Full Text Available An analysis for the mixed convection boundary layers in the stagnation-point flow toward a stretching vertical sheet is carried out via symmetry analysis. By employing Lie group method to the given system of nonlinear partial differential equations, we can obtain information about the invariants and symmetries of these equations. This information can be used to determine the similarity variables that will reduce the number of independent variables in the system. The transformed ordinary differential equations are solved numerically for some values of the parameters involved using fifth-order Improved Runge-Kutta Method (IRK5 coupled with shooting method. The features of the flow and heat transfer characteristics are analyzed and discussed in detail. Both cases of assisting and opposing flows are considered. This paper' results in comparison with known results are excellent.

  20. Achievement Goals and Achievement Emotions: A Meta-Analysis

    Science.gov (United States)

    Huang, Chiungjung

    2011-01-01

    This meta-analysis synthesized 93 independent samples (N = 30,003) in 77 studies that reported in 78 articles examining correlations between achievement goals and achievement emotions. Achievement goals were meaningfully associated with different achievement emotions. The correlations of mastery and mastery approach goals with positive achievement…

  1. Competition and achievement goals in work teams

    NARCIS (Netherlands)

    Heidemeier, H.; Bittner, Jenny V.

    2012-01-01

    This study examined how competition within teams influences which type of achievement goals employees adopt. We studied how dispositional learning-goal and performance-goal orientation interact with team-level competition and predict whether team members adopt state learning or performance achieveme

  2. Achieving the Goals of Sports Organizations

    OpenAIRE

    Horal, Filip

    2009-01-01

    The theoretical part focuses on setting and achieving of goals in organizations in general and identifies specific performance objectives in sports organizations. In the practical part examines the process of setting targets and performance in sport organizations to Jindřichohradecko.

  3. Spatially resolved X-ray emission measurements of the residual velocity during the stagnation phase of inertial confinement fusion implosion experiments

    Science.gov (United States)

    Ruby, J. J.; Pak, A.; Field, J. E.; Ma, T.; Spears, B. K.; Benedetti, L. R.; Bradley, D. K.; Berzak Hopkins, L. F.; Casey, D. T.; Döppner, T.; Eder, D.; Fittinghoff, D.; Grim, G.; Hatarik, R.; Hinkel, D. E.; Izumi, N.; Kilkenny, J. D.; Khan, S. F.; Knauer, J. P.; Kritcher, A. L.; Merrill, F. E.; Moody, J. D.; Nagel, S. R.; Park, H.-S.; Salmonson, J. D.; Sayre, D. B.; Callahan, D. A.; Hsing, W. W.; Hurricane, O. A.; Patel, P. K.; Edwards, M. J.

    2016-07-01

    A technique for measuring residual motion during the stagnation phase of an indirectly driven inertial confinement experiment has been implemented. This method infers a velocity from spatially and temporally resolved images of the X-ray emission from two orthogonal lines of sight. This work investigates the accuracy of recovering spatially resolved velocities from the X-ray emission data. A detailed analytical and numerical modeling of the X-ray emission measurement shows that the accuracy of this method increases as the displacement that results from a residual velocity increase. For the typical experimental configuration, signal-to-noise ratios, and duration of X-ray emission, it is estimated that the fractional error in the inferred velocity rises above 50% as the velocity of emission falls below 24 μm/ns. By inputting measured parameters into this model, error estimates of the residual velocity as inferred from the X-ray emission measurements are now able to be generated for experimental data. Details of this analysis are presented for an implosion experiment conducted with an unintentional radiation flux asymmetry. The analysis shows a bright localized region of emission that moves through the larger emitting volume at a relatively higher velocity towards the location of the imposed flux deficit. This technique allows for the possibility of spatially resolving velocity flows within the so-called central hot spot of an implosion. This information would help to refine our interpretation of the thermal temperature inferred from the neutron time of flight detectors and the effect of localized hydrodynamic instabilities during the stagnation phase. Across several experiments, along a single line of sight, the average difference in magnitude and direction of the measured residual velocity as inferred from the X-ray and neutron time of flight detectors was found to be ˜13 μm/ns and ˜14°, respectively.

  4. Quality Standard Research of Pills for Dispersing Stagnated Liver Qi for Promoting Bile Flow%疏肝利胆丸质量检测方法研究

    Institute of Scientific and Technical Information of China (English)

    杨瑞芳; 王静

    2015-01-01

    目的:建立疏肝利胆丸的质量控制标准。方法对处方中的党参、炒扁豆、姜厚朴、炒莱菔子、郁金、茯苓进行显微鉴别,同时对君药当归中的阿魏酸进行薄层鉴别。结果显微鉴别方法简单,易操作,薄层鉴别专属性强,方法可行。结论显微及薄层鉴别中所用方法简便,专属性强,重现性好,为疏肝利胆丸质量评价提供了依据。%Objective To establish the quality standard of pills for dispersing stagnated liver qi for promoting bile flow .Methods Conduct microscopic identification of Radix Codonopsis , fried lentils, Medicinal Magnolia Bark slices stir -baked with ginger juice, fried semen Raphani, curcuma root, poria in the prescription and at the meanwhile conduct TLC identification of ferulic acid in Angelica sinensis monarch drug .Results Microscopic identification is simple , easy to operate;TLC identification is high-ly specific and feasible .Conclusion The methods used in microscopic and TLC identification are easy , highly specific and reproducible , which provide the basis for quality evaluation of pills for dispersing stag-nated liver qi for promoting bile flow .

  5. Effects of variable properties on MHD heat and mass transfer flow near a stagnation point towards a stretching sheet in a porous medium with thermal radiation

    Institute of Scientific and Technical Information of China (English)

    A. M. Salem; Rania Fathy

    2012-01-01

    The effect of variable viscosity and thermal conductivity on steady magnetohydrodynamic(MHD)heat and mass transfer flow of viscous and incompressible fluid near a stagnation point towards a permeable stretching sheet embedded in a porous medium are presented,taking into account thermal radiation and internal heat genberation/absorbtion.The stretching velocity and the ambient fluid velocity are assumed to vary linearly with the distance from the stagnation point.The Rosseland approximation is used to describe the radiative heat flux in the energy equation.The governing fundamental equations are first transformed into a system of ordinary differential equations using a scaling group of transformations and are solved numerically by using the fourth-order Rung-Kutta method with the shooting technique.A comparison with previously published work has been carried out and the results are found to be in good agreement.The results are analyzed for the effect of different physical parameters,such as the variable viscosity and thermal conductivity,the ratio of free stream velocity to stretching velocity,the magnetic field,the porosity,the radiation and suction/injection on the flow,and the heat and mass transfer characteristics.The results indicate that the inclusion of variable viscosity and thermal conductivity into the fluids of light and medium molecular weight is able to change the boundary-layer behavior for all values of the velocity ratio parameter λ except for λ=1.In addition,the imposition of fluid suction increases both the rate of heat and mass transfer,whereas fluid injection shows the opposite effect.

  6. These Shoes Are Made for Walking: Sensitivity Performance Evaluation of Commercial Activity Monitors under the Expected Conditions and Circumstances Required to Achieve the International Daily Step Goal of 10,000 Steps.

    Directory of Open Access Journals (Sweden)

    Sandra O'Connell

    Full Text Available Physical activity is a vitally important part of a healthy lifestyle, and is of major benefit to both physical and mental health. A daily step count of 10,000 steps is recommended globally to achieve an appropriate level of physical activity. Accurate quantification of physical activity during conditions reflecting those needed to achieve the recommended daily step count of 10,000 steps is essential. As such, we aimed to assess four commercial activity monitors for their sensitivity/accuracy in a prescribed walking route that reflects a range of surfaces that would typically be used to achieve the recommended daily step count, in two types of footwear expected to be used throughout the day when aiming to achieve the recommended daily step count, and in a timeframe required to do so.Four commercial activity monitors were worn simultaneously by participants (n = 15 during a prescribed walking route reflective of surfaces typically encountered while achieving the daily recommended 10,000 steps. Activity monitors tested were the Garmin Vivofit ™, New Lifestyles' NL-2000 ™ pedometer, Withings Smart Activity Monitor Tracker (Pulse O2 ™, and Fitbit One ™.All activity monitors tested were accurate in their step detection over the variety of different surfaces tested (natural lawn grass, gravel, ceramic tile, tarmacadam/asphalt, linoleum, when wearing both running shoes and hard-soled dress shoes.All activity monitors tested were accurate in their step detection sensitivity and are valid monitors for physical activity quantification over the variety of different surfaces tested, when wearing both running shoes and hard-soled dress shoes, and over a timeframe necessary for accumulating the recommended daily step count of 10,000 steps. However, it is important to consider the accuracy of activity monitors, particularly when physical activity in the form of stepping activities is prescribed as an intervention in the treatment or prevention of a

  7. Bilingualism and academic achievement.

    Science.gov (United States)

    Han, Wen-Jui

    2012-01-01

    Using the Early Childhood Longitudinal Study, Kindergarten Cohort, this study examines the role that bilingualism plays in children's academic developmental trajectories during their early school years, with particular attention on the school environment (N = 16,380). Growth-curve results showed that despite starting with lower math scores in kindergarten, Mixed Bilingual children fully closed the math gap with their White English Monolingual peers by fifth grade. However, because non-English-Dominant Bilinguals and non-English Monolinguals started kindergarten with significantly lower reading and math scores compared to their English Monolingual peers, by fifth grade the former groups still had significantly lower scores. School-level factors explained about one third of the reductions in the differences in children's academic performance. PMID:22098584

  8. Attitude Towards Physics and Additional Mathematics Achievement Towards Physics Achievement

    Science.gov (United States)

    Veloo, Arsaythamby; Nor, Rahimah; Khalid, Rozalina

    2015-01-01

    The purpose of this research is to identify the difference in students' attitude towards Physics and Additional Mathematics achievement based on gender and relationship between attitudinal variables towards Physics and Additional Mathematics achievement with achievement in Physics. This research focused on six variables, which is attitude towards…

  9. Effects of Gender, Mathematics Anxiety and Achievement Motivation on College Students’ Achievement in Mathematics

    Directory of Open Access Journals (Sweden)

    Ajogbeje Oke James

    2013-07-01

    Full Text Available The urge to excel or perform maximally in mathematics varies from individual to individual because achievement motivation is often developed or learnt during socialization and learning experiences. The study examined the relationship between College of Education students’ achievement motivation and mathematics achievement, correlation coefficient between mathematics anxiety and college students’ achievement motivation as well as mathematics anxiety and mathematics achievement. The sample, 268 College of Education students offering mathematics as one of their subject combination, was selected using purposive sampling techniques. Three research instruments namely: Mathematics Anxiety Scale (MAS, Achievement Motivation Scale (AMS and Mathematics Achievement Test (MAT were used to collect data for the study. Data collected for the study were analyzed using correlational analysis and ANOVA. The results showed that a significantly low negative correlation coefficient existed between mathematics anxiety and mathematics achievement. There is a negative and significant correlation coefficient between mathematics anxiety and achievement motivation. Similarly, a positive and significant correlation coefficient also exists between achievement motivation and mathematics achievement. Based on the findings of the study, it was recommended that mathematics teachers should adopt activity based strategies and conducive learning environment in order to reduce college students’ anxieties in mathematics learning.

  10. Identifying learning techniques among high achievers

    Directory of Open Access Journals (Sweden)

    Shanmukananda P

    2013-04-01

    Full Text Available Background: In every college, it is noticed that in spite of being exposed to the same teaching modalities and adopting seemingly similar strategies, some students perform much better than their peers. This can be evaluated in the form of better academic performance in the internal assessments they undertake. This project is an endeavor to identify the learning techniques among high achievers which they employ to outperform others. We can also suggest the same to the medium and low achievers so that they can improve their academic performance. This study was conducted to identify different learning techniques adopted by high achievers and suggesting the same to medium and low achievers. Methods: After obtaining clearance from the institutional ethics committee, the high achievers were identified by selecting the upper third of the students in the ascending order of marks obtained in the consecutive three internal assessments in three consecutive batches. The identity of the students was not revealed. They were then administered an open ended questionnaire which addressed relevant issues. The most common and feasible techniques will be suggested to the medium and low achievers. Results: The respondents’ (n=101 replies were analyzed by calculating the percentages of responses, and assessing based on that, which were the most frequently adapted techniques by these high achievers Conclusions: High-achievers have a diligent study pattern; they not only study regularly, but also involve in group discussions and approach their teachers when in doubt. Additionally, they refer to other sources of information like the internet, demonstrating a proactive attitude towards studies. [Int J Basic Clin Pharmacol 2013; 2(2.000: 203-207

  11. Cherokee Culture and School Achievement.

    Science.gov (United States)

    Brown, Anthony D.

    1980-01-01

    Compares the effect of cooperative and competitive behaviors of Cherokee and Anglo American elementary school students on academic achievement. Suggests changes in teaching techniques and lesson organization that might raise academic achievement while taking into consideration tribal traditions that limit scholastic achievement in an…

  12. 1984—1988年中国农业增长滞缓探微%China' s Agricultural Stagnation in 1984-1988

    Institute of Scientific and Technical Information of China (English)

    向为

    2015-01-01

    1978年开始试行的家庭联产承包责任制极大推动了中国农村经济的复苏和增长,但其在全国普及后,中国农业却陷入增长滞缓泥沼. 基于对河南省商城县一位老农民的采访,通过个案分析发现当时乡、村两级地方组织以提留统筹费名义向农民收取的不合理税款削弱了农民的劳作积极性,使得大量农村人口外流,从而导致1984—1988年间中国农业增长陷入滞缓境地. 此外,分析发现1987年农业增长的正向波动缘于科学技术运用的滞后效应. 1978—1988年间全国农业,特别是河南省农业的宏观数据又再次验证了提留统筹费对农业增长的消极影响和科学技术在运用过程中存在的滞后效应,由此建议将农业赋税制度作为农村经济改革的重要抓手,同时着力完善科学技术在农村的引入推广方式.%Agricultural growth in cropping sector was trapped into stagnation after Household Responsibility System had been completely popularized in rural areas in China .Based on a case study from Henan province , it is discovered that "Tiliu" and "Tongchou" taxes allocated by the local government discouraged the agricultural production when farmers with heavy tax burden flowed to cities for jobs .Hence, the agricultural stagnation from 1984—1988 is enun-ciated.The Hysteresis hypothesis that it takes some time for farmers to adopt new technology is also proposed to ex -plain the sudden impulse of agricultural growth in 1987.The state and provincial macro agricultural data are used to validate the analysis .The conclusions suggest the agricultural fiscal system be a core object of economic reform in ru -ral areas in China .In addition , the way of introducing new technology in such areas should be improved .

  13. 疏肝解郁论治双心疾病%Treatment of Soothing Liver-Qi Stagnation and Dispel Melancholy for Psychological and Cardiovascular Diseases

    Institute of Scientific and Technical Information of China (English)

    段文慧; 史大卓

    2013-01-01

    心血管病患者多伴发紧张、焦虑、惊恐、悲伤和抑郁等精神心理问题,精神心理问题可增加心血管事件的发病率和病死率。二者共存于一个个体,现代医学称之为“双心疾病”。目前西医一般采用心血管病药物和抗焦虑、抗抑郁药联合治疗,但因药物之间存在相互作用,且患者依从性差,往往难以获得理想效果。作者长期临床观察发现,双心疾病的基本病机为肝气郁结、气机失调、气血失和,治疗当以疏肝解郁、调畅气机、调理气血为主。在此基础上,根据正虚邪实的轻重和兼夹病邪的不同属性,施以不同的扶正祛邪、调和气血方药,随证治之,常可收到较好疗效。%Patients with cardiovascular disease always have psychological problems such as tension ,anxiety,panic,sadness and depres-sion et al ,and psychological problems can increase the morbidity and mortality of cardiovascular events .We call it pshycardiological dis-ease in modern medicine when psychological problems and cardiovascular disease coexist in an individual .Drugs for cardiovascular dis-ease and anti-anxiety or anti-depression drugs are commonly used to treat pshycardiological disease .But due to the interactions between drugs ,and the poor compliance of patients ,it is difficult to have ideal effects for pshycardiological disease .After long-term clinical obser-vations ,we found that the basic pathogeneses of pshycardiological disease are stagnation of liver qi ,disorder of qi activity ,as well as dis-harmony of qi and blood .The treatment should be soothing liver-qi stagnation ,regulating qi activity ,regulating qi and blood .And then drugs that work to strengthen body resistance ,eliminate evil or regulate qi and blood should be used depending on the severity of vital qi deficiency and the different kinds of pathogenic factors to get a satisfactory therapeutic effect .

  14. Students' Achievement Goals, Learning-Related Emotions and Academic Achievement

    Directory of Open Access Journals (Sweden)

    Marko eLüftenegger

    2016-05-01

    Full Text Available In the present research, the recently proposed 3x2 model of achievement goals is tested and associations with achievement emotions and their joint influence on academic achievement are investigated. The study was conducted with 388 students using the 3x2 Achievement Goal Questionnaire including the six proposed goal constructs (task-approach, task-avoidance, self-approach, self-avoidance, other-approach, other-avoidance and the enjoyment and boredom scales from the Achievement Emotion Questionnaire. Exam grades were used as an indicator of academic achievement. Findings from CFAs provided strong support for the proposed structure of the 3x2 achievement goal model. Self-based goals, other-based goals and task-approach goals predicted enjoyment. Task-approach goals negatively predicted boredom. Task-approach and other-approach predicted achievement. The indirect effects of achievement goals through emotion variables on achievement were assessed using bias-corrected bootstrapping. No mediation effects were found. Implications for educational practice are discussed.

  15. Factors Influencing Seminar Learning and Academic Achievement.

    Science.gov (United States)

    Spruijt, Annemarie; Leppink, Jimmie; Wolfhagen, Ineke; Bok, Harold; Mainhard, Tim; Scherpbier, Albert; van Beukelen, Peter; Jaarsma, Debbie

    2015-01-01

    Many veterinary curricula use seminars, interactive educational group formats in which some 25 students discuss questions and issues relating to course themes. To get indications on how to optimize the seminar learning process for students, we aimed to investigate relationships between factors that seem to be important for the seminar learning process, and to determine how these seminar factors account for differences in students' achievement scores. A 57-item seminar evaluation (USEME) questionnaire was administered to students right after they attended a seminar. In total, 80 seminars distributed over years 1, 2, and 3 of an undergraduate veterinary medicine curriculum were sampled and 988 questionnaires were handed in. Principal factor analysis (PFA) was conducted on 410 questionnaires to examine which items could be grouped together as indicators of the same factor, and to determine correlations between the derived factors. Multilevel regression analysis was performed to explore the effects of these seminar factors and students' prior achievement scores on students' achievement scores. Within the questionnaire, four factors were identified that influence the seminar learning process: teacher performance, seminar content, student preparation, and opportunities for interaction within seminars. Strong correlations were found between teacher performance, seminar content, and group interaction. Prior achievement scores and, to a much lesser extent, the seminar factor group interaction appeared to account for differences in students' achievement scores. The factors resulting from the present study and their relation to the method of assessment should be examined further, for example, in an experimental setup. PMID:26075625

  16. Hydrodynamic performance and heat generation by centrifugal pumps.

    Science.gov (United States)

    Ganushchak, Y; van Marken Lichtenbelt, W; van der Nagel, T; de Jong, D S

    2006-11-01

    For over a century, centrifugal pumps (CP) have been used in various applications, from large industrial pumps to flow pumps for aquariums. However, the use of CP as blood pumps has a rather short history. Consequently, the hydraulic performance data for a blood CP are limited. The aim of our investigation was to study the hydraulic performance and the heat generation of three commercially available CP: Bio-Medicus Bio-Pump BP80 (Medtronic), Rotaflow (Jostra Medizintechnik), and DeltaStream DP2 (MEDOS Medizintechnik AQ). The study was performed using a circuit primed with a water-glycerin mixture with a dynamic viscosity of 0.00272 pa/s. Pressure-flow curves were obtained by a stepwise stagnation of the pump outlet or inlet. The temperature changes were observed using ThermaCAM SC2000 (Flir Systems). The pumps' performance in close to clinical conditions ('operating region') was analysed in this report. The 'operating region' in the case of the BP80 is positioned around the pressure-flow curve at a pump speed of 3000 rpm. In the case of the Rotaflow, the 'operating region' was between the pump pressure-flow curves at a speed of 3000 and 4000 rpm, and the DP2 was found between 7000 and 8000 rpm. The standard deviation of mean pressure through the pump was used to characterise the stability of the pump. In experiments with outlet stagnation, the BP80 demonstrated high negative association between flow and pressure variability (r = -0.68, p pumps demonstrated significantly higher variability of pressure in experiments with inlet stagnation in comparison to the experiments with outlet stagnation. The rise of relative temperature in the inlet of a pump was closely related to the flow rate. The heating of fluid was more pronounced in the 'zero-flow' mode, especially in experiments with inlet stagnation. In summary, (1) the 'zero-flow' regime, which is described in the manuals of some commercially-available pumps, is the use of the pump outside the allowable operating

  17. Wire number dependence of the implosion dynamics, stagnation, and radiation output of tungsten wire arrays at Z driver

    International Nuclear Information System (INIS)

    We report results of the experimental campaign, which studied the initiation, implosion dynamics, and radiation yield of tungsten wire arrays as a function of the wire number. The wire array dimensions and mass were those of interest for the Z-pinch driven Inertial Confinement Fusion (ICF) program. An optimization study of the x-ray emitted peak power, rise time, and full width at half maximum was effectuated by varying the wire number while keeping the total array mass constant and equal to ∼5.8 mg. The driver utilized was the ∼20-MA Z accelerator before refurbishment in its usual short pulse mode of 100 ns. We studied single arrays of 20-mm diameter and 1-cm height. The smaller wire number studied was 30 and the largest 600. It appears that 600 is the highest achievable wire number with present day's technology. Radial and axial diagnostics were utilized including crystal monochromatic x-ray backlighter. An optimum wire number of ∼375 was observed which was very close to the routinely utilized 300 for the ICF program in Sandia.

  18. Wire number dependence of the implosion dynamics, stagnation, and radiation output of tungsten wire arrays at Z driver

    Energy Technology Data Exchange (ETDEWEB)

    Mazarakis, Michael G.; Stygar, William A.; Sinars, Daniel B.; Cuneo, Michael E.; Nash, Thomas J.; Chandler, Gordon A.; Keith Matzen, M.; Porter, John L.; Struve, Kenneth W.; McDaniel, Dillon H. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States); Deeney, Christopher E. [National Nuclear Security Administration, Washington, D.C. 20585 (United States); Douglas, Melissa R. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Chittenden, Jerry [Imperial College, London, SW and 2BW (United Kingdom)

    2011-11-15

    We report results of the experimental campaign, which studied the initiation, implosion dynamics, and radiation yield of tungsten wire arrays as a function of the wire number. The wire array dimensions and mass were those of interest for the Z-pinch driven Inertial Confinement Fusion (ICF) program. An optimization study of the x-ray emitted peak power, rise time, and full width at half maximum was effectuated by varying the wire number while keeping the total array mass constant and equal to {approx}5.8 mg. The driver utilized was the {approx}20-MA Z accelerator before refurbishment in its usual short pulse mode of 100 ns. We studied single arrays of 20-mm diameter and 1-cm height. The smaller wire number studied was 30 and the largest 600. It appears that 600 is the highest achievable wire number with present day's technology. Radial and axial diagnostics were utilized including crystal monochromatic x-ray backlighter. An optimum wire number of {approx}375 was observed which was very close to the routinely utilized 300 for the ICF program in Sandia.

  19. Recent Achievement of Gas Electron Multiplier

    Institute of Scientific and Technical Information of China (English)

    XIA Yi-ben; WANG Lin-jun; ZHANG Ming-long; YANG Ying; ZHANG Wei-li; RUAN Jian-feng

    2004-01-01

    Gas electron multiplier (GEM) as a novel gas detector, due to it's simple structure, high performance, well compatibility etc. ,is widely used in high-energy physics, nuclear physics and other fields. In this review, the principle, recent achievements,developments and applications of GEM are mainly described.

  20. Is achievement in Australian chemistry gender based?

    Science.gov (United States)

    Beard, John; Fogliani, Charles; Owens, Chris; Wilson, Audrey

    1993-12-01

    This paper compares the performances of female and male secondary students in the 1991 and 1992 Australian National Chemistry Quizzes. Male students consistently achieved a higher mean score in all Year groups (7 to 12), even though the numbers of female and male entrants were approximately equal. Implications for class tests and assessment tasks are addressed.

  1. Student Perceptions of High-Achieving Classmates

    Science.gov (United States)

    Händel, Marion; Vialle, Wilma; Ziegler, Albert

    2013-01-01

    The reported study investigated students' perceptions of their high-performing classmates in terms of intelligence, social skills, and conscientiousness in different school subjects. The school subjects for study were examined with regard to cognitive, physical, and gender-specific issues. The results show that high academic achievements in…

  2. Science Achievement of Secondary Agricultural Education Students

    Science.gov (United States)

    Clark, Sara Vicky

    2012-01-01

    The purposes of this quantitative descriptive and correlational study were to describe the science achievements of secondary agricultural education students and determine if the number of agricultural education courses passed, FFA involvement, and SAE participation would statistically significantly improve students' performance on science…

  3. Mixed convection stagnation-point flow of nanofluids over a stretching/shrinking sheet in a porous medium with internal heat generation/absorption

    Directory of Open Access Journals (Sweden)

    Dulal Pal

    2015-05-01

    Full Text Available In this paper, we analyzed the buoyancy-driven radiative non-isothermal heat transfer in a nanofluid stagnation-point flow over a stretching/shrinking sheet embedded in a porous medium.The effects of thermal radiation and internal heat generation/absorption along with suction/injection at the boundary are also considered. Three different types of nanofluids, namely the Copper-water, the Alumina-water and the Titanium dioxide water are considered. The resulting coupled nonlinear differential equations are solved numerically by a fifth-order Runge-Kutta-Fehlberg integration scheme with a shooting technique. A good agreement is found between the present numerical results and the available results in the literature for some special cases. The effects of the physical parameters on the flow and temperature characteristics are presented through tables and graphs, and the salient features are discussed. The results obtained reveal many interesting behaviors that warrant further study on the heat transfer enhancement due to the nanofluids.

  4. Mixed Convection Boundary-layer Flow of a Nanofluid Near Stagnation-point on a Vertical Plate with Effects of Buoyancy Assisting and Opposing Flows

    Directory of Open Access Journals (Sweden)

    Hossein Tamim

    2013-07-01

    Full Text Available In this study, the steady laminar mixed convection boundary layer flow of a nanofluid near the stagnation-point on a vertical plate with prescribed surface temperature is investigated. Here, both assisting and opposing flows are considered and studied. Using appropriate transformations, the system of partial differential equations is transformed into an ordinary differential system of two equations, which is solved numerically by shooting method, coupled with Runge-Kutta scheme. Three different types of nanoparticles, namely copper Cu, alumina Al2O3 and titania TiO2 with water as the base fluid are considered. Numerical results are obtained for the skin-friction coefficient and Nusselt number as well as for the velocity and temperature profiles for some values of the governing parameters, namely, the nanoparticle volume fraction parameter &Phiand mixed convection parameter &lambda It is found that the highest rate of heat transfer occurs in the mixed convection with assisting flow while the lowest one occurs in the mixed convection with opposing flow. Moreover, the skin friction coefficient and the heat transfer rate at the surface are highest for copper–water nanofluid compared to the alumina–water and titania–water nanofluids.

  5. The Mechanics of Human Achievement

    Science.gov (United States)

    Duckworth, Angela L.; Eichstaedt, Johannes C.; Ungar, Lyle H.

    2015-01-01

    Countless studies have addressed why some individuals achieve more than others. Nevertheless, the psychology of achievement lacks a unifying conceptual framework for synthesizing these empirical insights. We propose organizing achievement-related traits by two possible mechanisms of action: Traits that determine the rate at which an individual learns a skill are talent variables and can be distinguished conceptually from traits that determine the effort an individual puts forth. This approach takes inspiration from Newtonian mechanics: achievement is akin to distance traveled, effort to time, skill to speed, and talent to acceleration. A novel prediction from this model is that individual differences in effort (but not talent) influence achievement (but not skill) more substantially over longer (rather than shorter) time intervals. Conceptualizing skill as the multiplicative product of talent and effort, and achievement as the multiplicative product of skill and effort, advances similar, but less formal, propositions by several important earlier thinkers. PMID:26236393

  6. Mathematics Achievement in High- and Low-Achieving Secondary Schools

    Science.gov (United States)

    Mohammadpour, Ebrahim; Shekarchizadeh, Ahmadreza

    2015-01-01

    This paper identifies the amount of variance in mathematics achievement in high- and low-achieving schools that can be explained by school-level factors, while controlling for student-level factors. The data were obtained from 2679 Iranian eighth graders who participated in the 2007 Trends in International Mathematics and Science Study. Of the…

  7. 年级之间学业情绪与学业成绩的研究成果及展望%Research Achievements and Outlooks on the Correlation between Academic Emotions and Academic Performance

    Institute of Scientific and Technical Information of China (English)

    陈维维; 黄丽婷; 梁源; 蒋莎莎

    2013-01-01

      学业情绪是影响学生学业成绩的非智力的重要因素之一,研究两者之间的关系对教学有重大的意义。通过对不同年级学业情绪与学业成绩的研究成果进行分析和对比,探究不同阶段间两者相互关系存在的普遍性以及特殊性,为更好地改善教学方式,真正做到因材施教提供依据,并由此展望学业情绪未来的发展趋向。%  Academic emotion is one of the important non-intelligent factors influencing students’ academic performance. The correlation between academic emotion and students’ academic performance is analyzed between different grades, so as to investigate their universality and particularity, and to provide reference for teaching in accordance with students’ aptitude, as well as for the prediction on the outlook of students’ academic emotional tendency.

  8. Causes of and Solutions to the Achievement Gap: Teachers' Perceptions

    Science.gov (United States)

    Ratcliff, Nancy J.; Costner, Richard H.; Carroll, Kimberly L.; Jones, Cathy R.; Sheehan, Heather Chase; Hunt, Gilbert H.

    2016-01-01

    Survey results from 874 educators regarding the achievement gap are shared. The importance of the achievement gap, causes of and solutions to the achievement gap, and performance expectations for students in their schools are explored. Implications for teacher educators are discussed as related to both pre-service and in-service training programs.

  9. Achievement goals in the workplace : Conceptualization, prevalence, profiles, and outcomes

    NARCIS (Netherlands)

    Van Yperen, Nico W.; Orehek, Edward

    2013-01-01

    The purpose of the present paper is to discuss an important component of workers' willingness to perform at their jobs, that is, their achievement motivation. More specifically, we will discuss the conceptualization of the four achievement goals from the 2 x 2 achievement goal framework and present

  10. Indoor test for thermal performance of the Sunmaster evacuated tube (liquid) solar collector

    Science.gov (United States)

    1979-01-01

    The test procedures used to obtain the thermal performance data for a solar collector under simulated conditions are presented. Tests included a stagnation test, a time constant test, a thermal efficiency test, an incident angle modifier test, and a hot fill test. All tests were performed at ambient conditions and the transient effect and the incident angle effect on the collector were determined. The solar collector is a water working fluid type.

  11. Attribution theory in science achievement

    Science.gov (United States)

    Craig, Martin

    Recent research reveals consistent lags in American students' science achievement scores. Not only are the scores lower in the United States compared to other developed nations, but even within the United States, too many students are well below science proficiency scores for their grade levels. The current research addresses this problem by examining potential malleable factors that may predict science achievement in twelfth graders using 2009 data from the National Assessment of Educational Progress (NAEP). Principle component factor analysis was conducted to determine the specific items that contribute to each overall factor. A series of multiple regressions were then analyzed and formed the predictive value of each of these factors for science achievement. All significant factors were ultimately examined together (also using multiple regression) to determine the most powerful predictors of science achievement, identifying factors that predict science achievement, the results of which suggested interventions to strengthen students' science achievement scores and encourage persistence in the sciences at the college level and beyond. Although there is a variety of research highlighting how students in the US are falling behind other developing nations in science and math achievement, as yet, little research has addressed ways of intervening to address this gap. The current research is a starting point, seeking to identify malleable factors that contribute to science achievement. More specifically, this research examined the types of attributions that predict science achievement in twelfth grade students.

  12. APPLICATION OF ANT COLONY OPTIMISATION ALGORITHM WITH STAGNATION DETECTION IN 2D HP LATTICE MODEL%带有停滞检测的蚁群算法在2D HP 格点模型中的应用

    Institute of Scientific and Technical Information of China (English)

    刘羽; 熊壬浩

    2016-01-01

    为了提高蛋白质折叠结构预测的求解效率,针对2D HP 格点模型,研究蚁群 ACO(Ant Colony Optimization)算法在该问题上的应用。采用四元组表示绝对的折叠方向,并建立构象和解的一一对应关系。通过实验对算法各阶段的常用策略、方法进行比较分析。为了防止搜索陷入停滞,引入位置信息素停滞比和序列信息素停滞比两个参数,使用一种新的停滞检测机制。实验结果表明,改进的算法在保证预测质量的前提下,显著地提升了收敛速度。%Aiming at 2D HP lattice model we studied the application of ant colony optimisation algorithm on protein folding structure prediction in order to improve the efficiency of its solution.We used the quadruple to express absolute folding direction,and established the one-to-one correspondence between conformation and solution.Through experiment we made the comparative analyses on common strategies and methods in each stage of the algorithm.To prevent the search from going to stagnation,we introduced two parameters,the position pheromone stagnation ratio and the sequence pheromone stagnation ratio,and applied a new stagnation detection mechanism as well. Experimental results showed that the improved algorithm remarkably accelerated the convergence speed on the premise of ensuring prediction quality.

  13. Schoolbook Texts: Behavioral Achievement Priming in Math and Language.

    Science.gov (United States)

    Engeser, Stefan; Baumann, Nicola; Baum, Ingrid

    2016-01-01

    Prior research found reliable and considerably strong effects of semantic achievement primes on subsequent performance. In order to simulate a more natural priming condition to better understand the practical relevance of semantic achievement priming effects, running texts of schoolbook excerpts with and without achievement primes were used as priming stimuli. Additionally, we manipulated the achievement context; some subjects received no feedback about their achievement and others received feedback according to a social or individual reference norm. As expected, we found a reliable (albeit small) positive behavioral priming effect of semantic achievement primes on achievement in math (Experiment 1) and language tasks (Experiment 2). Feedback moderated the behavioral priming effect less consistently than we expected. The implication that achievement primes in schoolbooks can foster performance is discussed along with general theoretical implications.

  14. Predicting genetics achievement in nonmajors college biology

    Science.gov (United States)

    Mitchell, Angela; Lawson, Anton E.

    Students enrolled in a non-majors college biology course were pretested to determine their level of intellectual development, degree of field independence, mental capacity, amount of prior genetics knowledge, and amount of fluid intelligence. They were then taught a unit on Mendelian genetics. The only student variables found to not account for a significant amount of variance on a test of reading comprehension and/or a test of genetics achievement was amount of prior genetics knowledge. Developmental level was found to be the most consistent predictor of performance, suggesting that a lack of general hypothetico-deductive reasoning ability is a major factor limiting achievement among these students.

  15. The Process of Science Achievement.

    Science.gov (United States)

    Papanastasiou, Constantinos; Papanastasiou, Elena C.

    2002-01-01

    Investigates the science achievement of 8th grade students in Cyprus by using a structural equation model with three exogenous constructs--family's educational background, reinforcements, and school climate, and three endogenous constructs--teaching, student attitudes, and achievement. Proposes a model for the effects of family, school, student…

  16. Physical Activity and Academic Achievement

    Centers for Disease Control (CDC) Podcasts

    2014-12-09

    This podcast highlights the evidence that supports the link between physical activity and improved academic achievement. It also identifies a few actions to support a comprehensive school physical activity program to improve academic achievement.  Created: 12/9/2014 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 12/9/2014.

  17. Healthy Eating and Academic Achievement

    Centers for Disease Control (CDC) Podcasts

    2014-12-09

    This podcast highlights the evidence that supports the link between healthy eating and improved academic achievement. It also identifies a few actions to support a healthy school nutrition environment to improve academic achievement.  Created: 12/9/2014 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 12/9/2014.

  18. Perils of Standardized Achievement Testing

    Science.gov (United States)

    Haladyna, Thomas M.

    2006-01-01

    This article argues that the validity of standardized achievement test-score interpretation and use is problematic; consequently, confidence and trust in such test scores may often be unwarranted. The problem is particularly severe in high-stakes situations. This essay provides a context for understanding standardized achievement testing, then…

  19. Peer relationships and academic achievement

    Directory of Open Access Journals (Sweden)

    Krnjajić Stevan B.

    2002-01-01

    Full Text Available After their childhood, when children begin to establish more intensive social contacts outside family, first of all, in school setting, their behavior i.e. their social, intellectual, moral and emotional development is more strongly affected by their peers. Consequently, the quality of peer relationships considerably affects the process of adaptation and academic achievement and their motivational and emotional attitude towards school respectively. Empirical findings showed that there is bi-directional influence between peer relationships and academic achievement. In other words, the quality of peer relationships affects academic achievement, and conversely, academic achievement affects the quality of peer relationships. For example, socially accepted children exhibiting prosocial, cooperative and responsible forms of behavior in school most frequently have high academic achievement. On the other hand, children rejected by their peers often have lower academic achievement and are a risk group tending to delinquency, absenteeism and drop out of school. Those behavioral and interpersonal forms of competence are frequently more reliable predictors of academic achievement than intellectual abilities are. Considering the fact that various patterns of peer interaction differently exert influence on students' academic behavior, the paper analyzed effects of (a social competence, (b social acceptance/rejection, (c child's friendships and (d prosocial behavior on academic achievement.

  20. Achieving single channel, full duplex wireless communication

    KAUST Repository

    Choi, Jung Il

    2010-01-01

    This paper discusses the design of a single channel full-duplex wireless transceiver. The design uses a combination of RF and baseband techniques to achieve full-duplexing with minimal effect on link reliability. Experiments on real nodes show the full-duplex prototype achieves median performance that is within 8% of an ideal full-duplexing system. This paper presents Antenna Cancellation, a novel technique for self-interference cancellation. In conjunction with existing RF interference cancellation and digital baseband interference cancellation, antenna cancellation achieves the amount of self-interference cancellation required for full-duplex operation. The paper also discusses potential MAC and network gains with full-duplexing. It suggests ways in which a full-duplex system can solve some important problems with existing wireless systems including hidden terminals, loss of throughput due to congestion, and large end-to-end delays. Copyright 2010 ACM.

  1. Capacity achieving multiwrite WOM codes

    OpenAIRE

    Shpilka, Amir

    2012-01-01

    In this paper we give an explicit construction of a capacity achieving family of binary t-write WOM codes for any number of writes t, that have a polynomial time encoding and decoding algorithms. The block length of our construction is N=(t/\\epsilon)^{O(t/(\\delta\\epsilon))} when \\epsilon is the gap to capacity and encoding and decoding run in time N^{1+\\delta}. This is the first deterministic construction achieving these parameters. Our techniques also apply to larger alphabets.

  2. Achievements of sustainable manufacturing by machining

    OpenAIRE

    J. Kopac

    2009-01-01

    Purpose: Manufacturing industry is under increasing pressure of global competition, stricter environmental legislation and supply-chain demand for improved sustainability performance. The latter can be achieved through changes in products, processes and systems which are related to the sustainability issues. Sustainability in manufacturing is an appropriate approach; however it is still unified to a higher production rate and benefit. To encounter this problem academic, scientific, cultural a...

  3. Hungary's banking sector: achievements and challenges

    OpenAIRE

    Várhegyi, Éva

    2002-01-01

    Hungary is generally considered one of the best performing transition countries, having been successful in achieving macroeconomic stabilisation and in creating a market-driven economic system (see, for instance, Fischer and Sahay, 2000; and Weder, 2001). In terms of financial sector reforms, the country is also considered in the advanced league (Bokros, 2001). While we agree to this assessment, it is also true that the degree of monetisation and bank intermediation in the Hungarian economy i...

  4. Achieving Better Learning Performance through the Discussion Activity in Facebook

    Science.gov (United States)

    Orawiwatnakul, Wiwat; Wichadee, Saovapa

    2016-01-01

    This study was conducted to see the effectiveness of using Facebook for expressing opinions on given topics to improve students' oral proficiency and critical thinking skills in an English class at a private university. The participants were 80 students enrolled in a course which emphasized the use of English for expressing ideas. Three research…

  5. Achieving Integrated Performance Management with the Corporate University

    Science.gov (United States)

    Dealtry, Richard

    2005-01-01

    Purpose: This article aims to deliver synoptic perspectives on the evolution taking place in corporate university management best practice. Design/methodology/approach: The insights are based on the author's co-creative client experience in the design, management and impact studies of this business and organisation development intervention. The…

  6. Dimensional consistency achieved in high-performance synchronizing hubs

    Directory of Open Access Journals (Sweden)

    García, P.

    2013-02-01

    Full Text Available The tolerances of parts produced for the automotive industry are so tight that any small process variation may mean that the product does not fulfill them. As dimensional tolerances decrease, the material properties of parts are expected to be improved. Depending on the dimensional and material requirements of a part, different production routes are available to find robust processes, minimizing cost and maximizing process capability. Dimensional tolerances have been reduced in recent years, and as a result, the double pressing-double sintering production via (“2P2S” has again become an accurate way to meet these increasingly narrow tolerances. In this paper, it is shown that the process parameters of the first sintering have great influence on the following production steps and the dimensions of the final parts. The roles of factors other than density and the second sintering process in defining the final dimensions of product are probed. All trials were done in a production line that produces synchronizer hubs for manual transmissions, allowing the maintenance of stable conditions and control of those parameters that are relevant for the product and process.

    Las tolerancias en componentes fabricados para la industria del automóvil son tan estrechas que cualquier modificación en las variables del proceso puede provocar que no se cumplan. Una disminución de las tolerancias dimensionales, puede significar una mejora en las propiedades de las piezas. Dependiendo de los requerimientos dimensionales y del material, distintas rutas de procesado pueden seguirse para encontrar un método de procesado robusto, que minimice costes y maximice la capacidad del proceso. En los últimos años, la tolerancia dimensional se ha ajustado gracias a métodos de procesado como el doble prensado/doble sinterizado (“2P2S”, método de gran precisión para conseguir estrechas tolerancias. En este trabajo, se muestra que los parámetros de procesado del primer ciclo de sinterización tienen una gran importancia en los pasos siguientes y en las dimensiones finales alcanzadas. Todos los ciclos se han realizado en una línea real de fabricación de cubos sincronizadores para cambio manual, asegurando el mantenimiento de condiciones estables y control de proceso relevante para el producto y el proceso en sí mismo.

  7. Connecting Achievement Motivation to Performance in General Chemistry

    Science.gov (United States)

    Ferrell, Brent; Phillips, Michael M.; Barbera, Jack

    2016-01-01

    Student success in chemistry is inherently tied to motivational and other affective processes. We investigated three distinct constructs tied to motivation: self-efficacy, interest, and effort beliefs. These variables were measured twice over the course of a semester in three sections of a first-semester general chemistry course (n = 170). We…

  8. Human Resource Management in Small Businesses: Achieving Peak Performance

    OpenAIRE

    DREW, EILEEN PATRICIA

    2011-01-01

    PUBLISHED Cheltenham, UK. Northampton, MA, USA Series: New Horizons in Management This chapter addresses the largely under-researched theme of how entrepreneurs in Ireland manage their business lives in parallel with their family commitments, with specific reference to dependent children. Since the emergence of dual-earner couples as ?typical?, there has been an expanding attention to the working lives of parents and the issue of work?family conflict in the conte...

  9. Achievement and New Challenges for High Performance Materials in Europe

    International Nuclear Information System (INIS)

    The European approach in the framework of nuclear energy advancement is described, in the light of such prominent objectives as safety, sustainability and transmutation of nuclear waste. The highlights are given on innovation and safety related design aspects of relevant fast neutron reactor component and systems. The materials requirements and related new challenges on materials for selected systems as decay heat removal systems, energy conversion systems, core components, etc., will be discussed and related European R&D programmes presented. (author)

  10. Iranian Students' Performance on the IELTS: A Question of Achievement

    Science.gov (United States)

    Ghaemi, Farid; Daftarifard, Parisa; Shirkhani, Servat

    2011-01-01

    Reading comprehension has won much effort on the part of teachers, testers, and researchers in Iran due to the fact that the immediate need of Iranian students at different university levels is the ability to read in order to get new information on the topic they are studying. The question raised is how much reading practice can move learners…

  11. Increase in protectionism and its impact on Sri Lanka's performance in global markets

    OpenAIRE

    Kaminski, Bartlomiej; Ng, Francis

    2013-01-01

    Sri Lanka's external performance defies global trends on two counts. First, the level of openness as measured by the ratio of trade in goods and services, after a strong increase in 1987-95 and stagnation in 1996-2004, sharply fell in 2005-10 to the levels experienced during the era of import substitution. Second, the share of clothing in manufactured exports has remained largely unchanged...

  12. Reading Achievement, Attitude toward Reading, and Reading Self-Esteem of Historically Low Achieving Students

    Science.gov (United States)

    Kaniuka, Theodore S.

    2010-01-01

    The main purpose of schools is to improve the academic performance of all students and more recently with special regard to those that have historically struggled to meet state achievement goals. In an effort to attain these goals, educators have utilized many approaches including enhancing student self-esteem as a precursor to improving the…

  13. 微极流体向受热面的MHD驻点流动%MHD Stagnation Point Flow of a Micropolar Fluid Towards a Heated Surface

    Institute of Scientific and Technical Information of China (English)

    M·M·阿斯拉夫

    2011-01-01

    The problem of two dimensional stagnation point flow of an electrically conducting micropolar fluid impinging normally on a heated surface in the presence of a uniform transverse magnetic field was analyzed. The governing continuity, momentum, angular momentum, and heat equations together with the associated boundary conditions were reduced to dimensionless form using suitable similarity transformations. The reduced self similar non-linear equations were then solved numerically by an algorithm based on finite difference discretization. The results were further refined by Richardson' s extrapolation. The effects of the magnetic parameter, the micropolar parameters, and the Prandtl number on the flow and temperature fields were predicted in tabular and graphical forms to show the important features of the solution.The study shows that the velocity and thermal boundary layers become thinner as the magnetic parameter is increased. The micropolar fluids display more reduction in shear stress as well as heat transfer rate than that exhibited by Newtonian fluids, which is beneficial in the flow and thermal control of polymeric processing.%分析了有均匀横向磁场作用时,导电微极流体垂直冲击受热面时形成的二维驻点流动问题.应用适当的相似转换,将连续、动量、角动量及热量的控制方程,及其相应的边界条件,简化为无量纲形式.然后,利用以有限差分离散化为基础的算法,求解简化了的自相似非线性方程.用Richardson外推法,进一步求精其结果.以图表形式表示磁场参数、微极性参数、Prandtl数对流动和温度场的影响,说明了其解的重要特性.研究表明,随着磁场参数的增大,速度和热边界层厚度变小了.与Newton流体相比较,微极流体的剪应力和传热率出现明显的减少,这对聚合物生产过程中流体的流动和热量控制是有益的.

  14. Comparison of the Two Modeling Methonds for Qi Stagnation and Blood Stasis%两种气滞血瘀证造模方法的比较

    Institute of Scientific and Technical Information of China (English)

    王婷婷; 贾乘; 宁天一; 姜静; 程嘉艺

    2013-01-01

    To compare methods of rat modeling for Qi stagnation and blood stasis for serving the experimental of etiological factors and pathogenesis. Methods; Apply various stimulations such as noise, light, electricity, tail - clamping, icewater - bath,bondage and adrenaline injection to establish the rat mode. Adopt the pressure sensing technology of MOTO to detect hemorheology - related indicators, use the coagulation method to detect coagulation - related indicators. Results: In hemorheology, compared with the negative control group, the viscosity of whole blood of high, medium, low shear and plasma viscosity increased in the multi - factor stimulation group (P < 0. 05). The viscosity of whole blood of high shear and plasma viscosity increased in the adrenaline injection group (P <0. 05). The fibrinogen content in blood coagulation indicated significant increase in both group(P <0. 05). Conclusion; Both multi -factor stimulation and adrenaline injection can lead to blood stasis. Adrenaline injection method can be convenient and easy. Multi - factor stimulation group relatively conform the theory of etiology and pathogenesis.%目的:比较两种大鼠气滞血瘀证模型的建立方法,为研究气滞血瘀病因病机提供实验基础.方法:分别采用声光电、夹尾、束缚、冰水浴多种刺激联合应用及肾上腺素注射的方法造模.采用MOTO压力传感技术检测血液流变学相关指标,采用凝固法检测凝血四项相关指标.结果:与空白对照组相比,多因素刺激组大鼠血液流变学指标中全血高、中、低切粘度与血浆黏度均显著升高(P<0.05),肾上腺素组大鼠全血高切粘度与血浆黏度显著升高(P<0.05);两组大鼠凝血四项指标中纤维蛋白原含量均显著升高(P<0.01).结论:多因素刺激与肾上腺素注射法均能导致动物出现血瘀状态,肾上腺素注射法方便易行,多因素刺激组较符合中医病因病机理论.

  15. 基于文献研究的肝郁证现代医学诊断规律探析%Analysis of the Diagnostic Law of Modern Medicine on Liver Qi Stagnation Based on Literature Research

    Institute of Scientific and Technical Information of China (English)

    马青; 司富春

    2013-01-01

    Objective To analyze the diagnostic law of modern medicine on liver qi stagnation based on clinical research. Methods The retrieval standard was implemented. The literatures of clinical research on liver qi stagnation from 1992 to 2012 that were in compliance with the standard were collected. SPSS17. 0 statistical measure was adopted to analyze the frequency distributions of the relevant disorders,disease category and positive indexes of liver qi stagnation pattern/syndrome. Results Of 40 literatures retrieved,16 sorts of diseases were involved,the total case frequency was 2013,8 categories were classified;the diseases in the urogenital system accounted for 42. 50% on the first top of the list,the diseases in the digestive system for 27. 50% on the second top;the case frequencies were 706 and 388 for climacteric syndrome and breast hyperplasia respectively, occupying the first and second tops; the total frequency of the relevant positive indexes was 6354,including 69 categories,in which,the frequency of liver qi stagnation integral was 840, occupying the first top and that of estradiol was 825 , occupying the second top. Conclusion The diseases in the urogenital system form the main disease category of liver qi stagnation. Climacteric syndrome and breast hyperplasia are the main relevant diseases. The liver qi stagnation integral and estradiol are the main relevant factors of modern clinical pattern/syndrome differentiation.%目的 探析肝郁证现代医学临床研究诊断规律.方法 制定检索标准,对1992~2012年期间符合检索标准的肝郁证临床研究文献收集、整理,应用SPSS17.0统计分析肝郁证的相关疾病、疾病类别、阳性指标频率分布.结果 检索到40篇文献中涉及疾病16种,病例总频次2013,归为8大种类,泌尿生殖系统疾病占42.50%,居第一位,消化系统疾病占27.50%,居第二位,更年期综合征、乳腺增生病例频次分别为706、388,居疾病第一、第二位;

  16. Curricular Diversity and Academic Achievement.

    Science.gov (United States)

    Wilson, Reginald

    1991-01-01

    Educational achievement should be intellectually and philosophically divorced from cultural affirmation, which is merely a byproduct of the inclusion of diverse voices in the search for truth. A model based on the relationship between the valuation of oneself by others and by oneself is presented to explain differential effects of schooling on…

  17. Epistemological Beliefs and Academic Achievement

    Science.gov (United States)

    Arslantas, Halis Adnan

    2016-01-01

    This study aimed to identify the relationship between teacher candidates' epistemological beliefs and academic achievement. The participants of the study were 353 teacher candidates studying their fourth year at the Education Faculty. The Epistemological Belief Scale was used which adapted to Turkish through reliability and validity work by…

  18. Goal Setting to Achieve Results

    Science.gov (United States)

    Newman, Rich

    2012-01-01

    Both districts and individual schools have a very clear set of goals and skills for their students to achieve and master. In fact, except in rare cases, districts and schools develop very detailed goals they wish to pursue. In most cases, unfortunately, only the teachers and staff at a particular school or district-level office are aware of the…

  19. Achieving a sustainable service advantage.

    Science.gov (United States)

    Coyne, K P

    1993-01-01

    Many managers believe that superior service should play little or no role in competitive strategy; they maintain that service innovations are inherently copiable. However, the author states that this view is too narrow. For a company to achieve a lasting service advantage, it must base a new service on a capability gap that competitors cannot or will not copy.

  20. Numerical investigation of heat transfer performance of synthetic jet impingement onto dimpled/protrusioned surface

    Directory of Open Access Journals (Sweden)

    Zhang Di

    2015-01-01

    Full Text Available Dynamic mesh methods and user defined functions are adopted and the shear stress transport k-ω turbulent model has been used in the numerical investigation of heat transfer performance of synthetic jet impingement onto dimple/protrusioned surface. The results show that the local time-averaged Nusselt number of the dimpled/protrusioned target surface tends to be much closer with that of flat cases with increasing of frequency. The heat transfer performance gets better when frequency increases. The area-averaged time-averaged Nusselt number of protrusioned target surface is the most close to that of flat cases when f = 320 Hz while it is the smallest among the synthetic jet cases in dimpled target surface. The heat transfer enhancement performance of synthetic jet is 30 times better than that of natural convection. The time-averaged Nusselt number of stagnation point in the protrusioned target surface is higher than that of flat target surface while it is lower in the dimpled surface than that of flat surface no matter in the synthetic jet, steady jet or natural convection cases. Meanwhile, the timeaveraged Nusselt number of stagnation point in the synthetic jet cases increases with the increasing of frequency. It is worth pointing out that the time-averaged Nusselt number of stagnation point is lower than that of steady cases when the frequency is low. However, it shows a bit higher than that of steady cases when f = 320 Hz.