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Sample records for modeling experiments suggest

  1. Hypnosis, suggestion, and suggestibility: an integrative model.

    Science.gov (United States)

    Lynn, Steven Jay; Laurence, Jean-Roch; Kirsch, Irving

    2015-01-01

    This article elucidates an integrative model of hypnosis that integrates social, cultural, cognitive, and neurophysiological variables at play both in and out of hypnosis and considers their dynamic interaction as determinants of the multifaceted experience of hypnosis. The roles of these variables are examined in the induction and suggestion stages of hypnosis, including how they are related to the experience of involuntariness, one of the hallmarks of hypnosis. It is suggested that studies of the modification of hypnotic suggestibility; cognitive flexibility; response sets and expectancies; the default-mode network; and the search for the neurophysiological correlates of hypnosis, more broadly, in conjunction with research on social psychological variables, hold much promise to further understanding of hypnosis.

  2. Didactic Experiments Suggest Enhanced Learning Outcomes

    DEFF Research Database (Denmark)

    Pals Svendsen, Lisbet

    2011-01-01

    and presenting material in the language studied, just as they were encouraged to systematically use evaluation processes to enhance learning outcomes. Eventually, increased grade point averages suggested that the experiment was successful. The article also mentions subsequent revisions to the original format...... and points the way for further research....

  3. Health service marketing: a suggested model.

    Science.gov (United States)

    Zaltman, G; Vertinsky, I

    1971-07-01

    Focus is on social marketing in a health context, and attention is directed to the development of a psychosocial model of health-related behavior with emphasis on developing countries. Each component of the model is identified and defined, with some of the interactions among its components noted. There are both advantages and limitations to using the model in a social marketing context. The model's primary contribution at this stage of its development is in structuring and organizing diverse sources of knowledge and data. New relationships are suggested which were not previously considered in the literature. The relationship between risk-taking and perceived susceptibility is 1 example. The model also provides a basis for simulating health processes, providing a testing ground for health policies before their actual implementation. The model's perspective is uniquely appropriate for the development of social marketing strategies, and it promises to encompass health market behavior in various cultural settings.

  4. Hotel Employees' Japanese Language Experiences: Implications and Suggestions.

    Science.gov (United States)

    Makita-Discekici, Yasuko

    1998-01-01

    Analyzes the Japanese language learning experiences of 13 hotel employees in Guam. Results of the study present implications and suggestions for a Japanese language program for the hotel industry. The project began as a result of hotel employees frustrations when they were unable to communicate effectively with their Japanese guests. (Auth/JL)

  5. Using suggestion to model different types of automatic writing.

    Science.gov (United States)

    Walsh, E; Mehta, M A; Oakley, D A; Guilmette, D N; Gabay, A; Halligan, P W; Deeley, Q

    2014-05-01

    Our sense of self includes awareness of our thoughts and movements, and our control over them. This feeling can be altered or lost in neuropsychiatric disorders as well as in phenomena such as "automatic writing" whereby writing is attributed to an external source. Here, we employed suggestion in highly hypnotically suggestible participants to model various experiences of automatic writing during a sentence completion task. Results showed that the induction of hypnosis, without additional suggestion, was associated with a small but significant reduction of control, ownership, and awareness for writing. Targeted suggestions produced a double dissociation between thought and movement components of writing, for both feelings of control and ownership, and additionally, reduced awareness of writing. Overall, suggestion produced selective alterations in the control, ownership, and awareness of thought and motor components of writing, thus enabling key aspects of automatic writing, observed across different clinical and cultural settings, to be modelled. Copyright © 2014. Published by Elsevier Inc.

  6. Children Undergoing Radiotherapy: Swedish Parents’ Experiences and Suggestions for Improvement

    Science.gov (United States)

    Mullaney, Tara; Nilsson, Kristina; Wickart-Johansson, Gun; Svärd, Anna-Maja; Nyholm, Tufve; Lindh, Jack; Lindh, Viveca

    2015-01-01

    Approximately 300 children, from 0 to 18 years old, are diagnosed with cancer in Sweden every year. Of these children, 80–90 of them undergo radiotherapy treatment for their cancer. Although radiotherapy is an encounter with advanced technology, few studies have investigated the child’s and the parent’s view of the procedure. As part of an ongoing multicenter study aimed to improve patient preparation and the care environment in pediatric radiotherapy, this article reports the findings from interviews with parents at baseline. The aim of the present study was twofold: to describe parents’ experience when their child undergoes radiotherapy treatment, and to report parents’ suggestions for improvements during radiotherapy for their children. Sixteen mothers and sixteen fathers of children between 2–16 years old with various cancer diagnoses were interviewed. Data were analyzed using content analysis. The findings showed that cancer and treatment turns people’s lives upside down, affecting the entire family. Further, the parents experience the child’s suffering and must cope with intense feelings. Radiotherapy treatment includes preparation by skilled and empathetic staff. The parents gradually find that they can deal with the process; and lastly, parents have suggestions for improvements during the radiotherapy treatment. An overarching theme emerged: that despair gradually turns to a sense of security, with a sustained focus on and close interaction with the child. In conclusion, an extreme burden was experienced around the start of radiotherapy, though parents gradually coped with the process. PMID:26509449

  7. Earthquake experience suggests new approach to seismic criteria

    International Nuclear Information System (INIS)

    Knox, R.

    1983-01-01

    Progress in seismic qualification of nuclear power plants as reviewed at the 4th Pacific Basin Nuclear Conference in Vancouver, September 1983, is discussed. The lack of experience of earthquakes in existing nuclear plants can be compensated by the growing experience of actual earthquake effects in conventional power plants and similar installations. A survey of the effects on four power stations, with a total of twenty generating units, in the area strongly shaken by the San Fernando earthquake in California in 1971 is reported. The Canadian approach to seismic qualification, international criteria, Canadian/Korean experience, safety related equipment, the Tadotsu test facility and seismic tests are discussed. (U.K.)

  8. Simple suggestions for including vertical physics in oil spill models

    International Nuclear Information System (INIS)

    D'Asaro, Eric; University of Washington, Seatle, WA

    2001-01-01

    Current models of oil spills include no vertical physics. They neglect the effect of vertical water motions on the transport and concentration of floating oil. Some simple ways to introduce vertical physics are suggested here. The major suggestion is to routinely measure the density stratification of the upper ocean during oil spills in order to develop a database on the effect of stratification. (Author)

  9. Halloween Costumes May Suggest Influence of Violent Models on Children.

    Science.gov (United States)

    Owen, John W.; Sterling, Bruce S.

    Halloween costumes may be used to examine the influence violent models have on children. On Halloween evening observers recorded the frequency of violent and nonviolent costumes worn by children. When all of the data are inspected they suggest that children confronted with several aggressive models may be more likely to identify with the…

  10. Modelling of Arabidopsis LAX3 expression suggests auxin homeostasis.

    Science.gov (United States)

    Mellor, Nathan; Péret, Benjamin; Porco, Silvana; Sairanen, Ilkka; Ljung, Karin; Bennett, Malcolm; King, John

    2015-02-07

    Emergence of new lateral roots from within the primary root in Arabidopsis has been shown to be regulated by the phytohormone auxin, via the expression of the auxin influx carrier LAX3, mediated by the ARF7/19 IAA14 signalling module (Swarup et al., 2008). A single cell model of the LAX3 and IAA14 auxin response was formulated and used to demonstrate that hysteresis and bistability may explain the experimentally observed 'all-or-nothing' LAX3 spatial expression pattern in cortical cells containing a gradient of auxin concentrations. The model was tested further by using a parameter fitting algorithm to match model output with qRT-PCR mRNA expression data following exogenous auxin treatment. It was found that the model is able to show good agreement with the data, but only when the exogenous auxin signal is degraded over time, at a rate higher than that measured in the experimental medium, suggesting the triggering of an endogenous auxin homeostasis mechanism. Testing the model over a more physiologically relevant range of extracellular auxin shows bistability and hysteresis still occur when using the optimised parameters, providing the rate of LAX3 active auxin transport is sufficiently high relative to passive diffusion. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Suggestions for Implementing First Year Experience Learning Communities in Teacher Education Programs

    Science.gov (United States)

    Hintz, Kathryn; Genareo, Vincent

    2017-01-01

    This article describes the creation of a First Year Experience learning community in a teacher education program. The First Year Experience model was adopted by the university because of declining enrollment, retention, and graduation rates and has been generally successful in the education department. With little information available for teacher…

  12. Suggestion of a Management Model: Total Entropy Management

    OpenAIRE

    Goksel Alpan,; Ismail Efil

    2011-01-01

    “Entropy” can be defined as the measure of disorder, uncertainty and consumed energy in a system or in the Universe. In the study, entropy concept is used as metaphor and it is aimed to construct the conceptual basis of a new management model which can be utilized to manage all entropy sources effectively. The study is conveyed with a multidisciplinary and holistic approach and by the use of qualitative research techniques. In the study, it is examined the relations of the entropy concept wit...

  13. A Model Suggestion to Predict Leverage Ratio for Construction Projects

    Directory of Open Access Journals (Sweden)

    Özlem Tüz

    2013-12-01

    Full Text Available Due to the nature, construction is an industry with high uncertainty and risk. Construction industry carries high leverage ratios. Firms with low equities work in big projects through progress payment system, but in this case, even a small negative in the planned cash flows constitute a major risk for the company.The use of leverage, with a small investment to achieve profit targets large-scale, high-profit, but also brings a high risk with it. Investors may lose all or the portion of the money. In this study, monitoring and measuring of the leverage ratio because of the displacement in cash inflows of construction projects which uses high leverage and low cash to do business in the sector is targeted. Cash need because of drifting the cash inflows may be seen due to the model. Work should be done in the early stages of the project with little capital but in the later stages, rapidly growing capital need arises.The values obtained from the model may be used to supply the capital held in the right time by anticipating the risks because of the delay in cashflow of construction projects which uses high leverage ratio.

  14. In vitro model suggests oxidative stress involved in keratoconus disease

    Science.gov (United States)

    Karamichos, D.; Hutcheon, A. E. K.; Rich, C. B.; Trinkaus-Randall, V.; Asara, J. M.; Zieske, J. D.

    2014-04-01

    Keratoconus (KC) affects 1:2000 people and is a disorder where cornea thins and assumes a conical shape. Advanced KC requires surgery to maintain vision. The role of oxidative stress in KC remains unclear. We aimed to identify oxidative stress levels between human corneal keratocytes (HCKs), fibroblasts (HCFs) and keratoconus cells (HKCs). Cells were cultured in 2D and 3D systems. Vitamin C (VitC) and TGF-β3 (T3) were used for 4 weeks to stimulate self-assembled extracellular matrix (ECM). No T3 used as controls. Samples were analyzed using qRT-PCR and metabolomics. qRT-PCR data showed low levels of collagen I and V, as well as keratocan for HKCs, indicating differentiation to a myofibroblast phenotype. Collagen type III, a marker for fibrosis, was up regulated in HKCs. We robustly detected more than 150 metabolites of the targeted 250 by LC-MS/MS per condition and among those metabolites several were related to oxidative stress. Lactate levels, lactate/malate and lactate/pyruvate ratios were elevated in HKCs, while arginine and glutathione/oxidized glutathione ratio were reduced. Similar patterns found in both 2D and 3D. Our data shows that fibroblasts exhibit enhanced oxidative stress compared to keratocytes. Furthermore the HKC cells exhibit the greatest level suggesting they may have a myofibroblast phenotype.

  15. Understanding the Experiences of Women in Jazz: A Suggested Model

    Science.gov (United States)

    Wehr, Erin L.

    2016-01-01

    Jazz has long been recognized as a male-dominated field, with females traditionally having only limited acceptance, often in the roles of singer and pianist. Researchers have explored sources of the gender imbalance in the field of jazz and jazz education, but there is no theory or framework to organize such findings. This directed content…

  16. Suggestibility, social support, and memory for a novel experience in young children

    Science.gov (United States)

    Quas, Jodi A.; Wallin, Allison R.; Papini, Silvia; Lench, Heather; Scullin, Matthew H.

    2010-01-01

    This study examined 5- and 6-year-olds' suggestibility and interviewer demeanor as joint predictors of their memory for a novel experience. Session 1 consisted of children taking part in a novel laboratory event. Session 2 took place after approximately a 1-week delay and consisted of children completing both a memory test concerning what happened during the prior event and the Video Suggestibility Scale for Children (VSSC). During the second session, the interviewer behaved either supportively or nonsupportively. Greater acquiescence on the VSSC was associated with fewer correct responses to misleading questions about the laboratory event in the supportive and nonsupportive conditions and with more errors in response to specific questions in the nonsupportive condition. Results indicate that individual differences in children's suggestibility are related to the accuracy of their memory for separate events, although some of these relations may vary depending on the context in which children are interviewed. PMID:15904929

  17. Modelling psychiatric and cultural possession phenomena with suggestion and fMRI.

    Science.gov (United States)

    Deeley, Quinton; Oakley, David A; Walsh, Eamonn; Bell, Vaughan; Mehta, Mitul A; Halligan, Peter W

    2014-04-01

    Involuntary movements occur in a variety of neuropsychiatric disorders and culturally influenced dissociative states (e.g., delusions of alien control and attributions of spirit possession). However, the underlying brain processes are poorly understood. We combined suggestion and fMRI in 15 highly hypnotically susceptible volunteers to investigate changes in brain activity accompanying different experiences of loss of self-control of movement. Suggestions of external personal control and internal personal control over involuntary movements modelled delusions of control and spirit possession respectively. A suggestion of impersonal control by a malfunctioning machine modelled technical delusions of control, where involuntary movements are attributed to the influence of machines. We found that (i) brain activity and/or connectivity significantly varied with different experiences and attributions of loss of agency; (ii) compared to the impersonal control condition, both external and internal personal alien control were associated with increased connectivity between primary motor cortex (M1) and brain regions involved in attribution of mental states and representing the self in relation to others; (iii) compared to both personal alien control conditions, impersonal control of movement was associated with increased activity in brain regions involved in error detection and object imagery; (iv) there were no significant differences in brain activity, and minor differences in M1 connectivity, between the external and internal personal alien control conditions. Brain networks supporting error detection and object imagery, together with representation of self and others, are differentially recruited to support experiences of impersonal and personal control of involuntary movements. However, similar brain systems underpin attributions and experiences of external and internal alien control of movement. Loss of self-agency for movement can therefore accompany different kinds of

  18. Gender differences in recognition of toy faces suggest a contribution of experience

    Science.gov (United States)

    Ryan, Kaitlin F.; Gauthier, Isabel

    2016-01-01

    When there is a gender effect, women perform better then men in face recognition tasks. Prior work has not documented a male advantage on a face recognition task, suggesting that women may outperform men at face recognition generally either due to evolutionary reasons or the influence of social roles. Here, we question the idea that women excel at all face recognition and provide a proof of concept based on a face category for which men outperform women. We developed a test of face learning to measures individual differences with face categories for which men and women may differ in experience, using the faces of Barbie dolls and of Transformers. The results show a crossover interaction between subject gender and category, where men outperform women with Transformers’ faces. We demonstrate that men can outperform women with some categories of faces, suggesting that explanations for a general face recognition advantage for women are in fact not needed. PMID:27923772

  19. Laval University and Lakehead University Experiments at TREC 2015 Contextual Suggestion Track

    Science.gov (United States)

    2015-11-20

    are downloaded synchronously into two data- bases MySQL and ElasticSearch. We query Elas- ticSearch for candidate suggestions while get train- ing data...from MySQL for MySQL has a better API for data retrieving though ElasticSearch also has all the data we need. ` Then a trained regressor will... MySQL and Elas- ticSearch as the crawler push data to the two sim- ultaneously. ` V. ONLINE RANKING MODEL A. Modeling of User Profile While

  20. Simulation - modeling - experiment

    International Nuclear Information System (INIS)

    2004-01-01

    After two workshops held in 2001 on the same topics, and in order to make a status of the advances in the domain of simulation and measurements, the main goals proposed for this workshop are: the presentation of the state-of-the-art of tools, methods and experiments in the domains of interest of the Gedepeon research group, the exchange of information about the possibilities of use of computer codes and facilities, about the understanding of physical and chemical phenomena, and about development and experiment needs. This document gathers 18 presentations (slides) among the 19 given at this workshop and dealing with: the deterministic and stochastic codes in reactor physics (Rimpault G.); MURE: an evolution code coupled with MCNP (Meplan O.); neutronic calculation of future reactors at EdF (Lecarpentier D.); advance status of the MCNP/TRIO-U neutronic/thermal-hydraulics coupling (Nuttin A.); the FLICA4/TRIPOLI4 thermal-hydraulics/neutronics coupling (Aniel S.); methods of disturbances and sensitivity analysis of nuclear data in reactor physics, application to VENUS-2 experimental reactor (Bidaud A.); modeling for the reliability improvement of an ADS accelerator (Biarotte J.L.); residual gas compensation of the space charge of intense beams (Ben Ismail A.); experimental determination and numerical modeling of phase equilibrium diagrams of interest in nuclear applications (Gachon J.C.); modeling of irradiation effects (Barbu A.); elastic limit and irradiation damage in Fe-Cr alloys: simulation and experiment (Pontikis V.); experimental measurements of spallation residues, comparison with Monte-Carlo simulation codes (Fallot M.); the spallation target-reactor coupling (Rimpault G.); tools and data (Grouiller J.P.); models in high energy transport codes: status and perspective (Leray S.); other ways of investigation for spallation (Audoin L.); neutrons and light particles production at intermediate energies (20-200 MeV) with iron, lead and uranium targets (Le Colley F

  1. Models and theories of prescribing decisions: A review and suggested a new model.

    Science.gov (United States)

    Murshid, Mohsen Ali; Mohaidin, Zurina

    2017-01-01

    To date, research on the prescribing decisions of physician lacks sound theoretical foundations. In fact, drug prescribing by doctors is a complex phenomenon influenced by various factors. Most of the existing studies in the area of drug prescription explain the process of decision-making by physicians via the exploratory approach rather than theoretical. Therefore, this review is an attempt to suggest a value conceptual model that explains the theoretical linkages existing between marketing efforts, patient and pharmacist and physician decision to prescribe the drugs. The paper follows an inclusive review approach and applies the previous theoretical models of prescribing behaviour to identify the relational factors. More specifically, the report identifies and uses several valuable perspectives such as the 'persuasion theory - elaboration likelihood model', the stimuli-response marketing model', the 'agency theory', the theory of planned behaviour,' and 'social power theory,' in developing an innovative conceptual paradigm. Based on the combination of existing methods and previous models, this paper suggests a new conceptual model of the physician decision-making process. This unique model has the potential for use in further research.

  2. Uncovering young children's emerging identities related to their literacy experiences: Suggestions to strengthen language education

    Directory of Open Access Journals (Sweden)

    Moen, Melanie Carmen

    2015-12-01

    Full Text Available The study explored how young children’s identities emerged from their drawings and accounts of their favourite stories as we argue the importance of understanding children in the context of school and language education. Sixty-six (n=66 children of two urban schools in Pretoria, South Africa were asked to write about and draw their favourite story. The participants were between the ages of six and seven years. Vygotsky’s socio-cultural theory and Chen’s theory of the construction of identity in a social context were used as conceptual framework. This conceptual framework could be linked to the findings which suggested that the children related their drawings and versions of their favourite stories to their interpretations of their life worlds. The prominent themes from the data could be associated with the self, the family, familiar objects and known animals. Their literacy experiences and the socio-cultural influences on the children’s construction of their identities were apparent in their work. We argue that teachers need to better understand how children understand themselves in relation to the world around them when making decisions about effective language education.

  3. Models and theories of prescribing decisions: A review and suggested a new model

    Directory of Open Access Journals (Sweden)

    Ali Murshid M

    2017-06-01

    Full Text Available To date, research on the prescribing decisions of physician lacks sound theoretical foundations. In fact, drug prescribing by doctors is a complex phenomenon influenced by various factors. Most of the existing studies in the area of drug prescription explain the process of decision-making by physicians via the exploratory approach rather than theoretical. Therefore, this review is an attempt to suggest a value conceptual model that explains the theoretical linkages existing between marketing efforts, patient and pharmacist and physician decision to prescribe the drugs. The paper follows an inclusive review approach and applies the previous theoretical models of prescribing behaviour to identify the relational factors. More specifically, the report identifies and uses several valuable perspectives such as the ‘persuasion theory - elaboration likelihood model’, the stimuli–response marketing model’, the ‘agency theory’, the theory of planned behaviour,’ and ‘social power theory,’ in developing an innovative conceptual paradigm. Based on the combination of existing methods and previous models, this paper suggests a new conceptual model of the physician decision-making process. This unique model has the potential for use in further research.

  4. Models and theories of prescribing decisions: A review and suggested a new model

    Science.gov (United States)

    Mohaidin, Zurina

    2017-01-01

    To date, research on the prescribing decisions of physician lacks sound theoretical foundations. In fact, drug prescribing by doctors is a complex phenomenon influenced by various factors. Most of the existing studies in the area of drug prescription explain the process of decision-making by physicians via the exploratory approach rather than theoretical. Therefore, this review is an attempt to suggest a value conceptual model that explains the theoretical linkages existing between marketing efforts, patient and pharmacist and physician decision to prescribe the drugs. The paper follows an inclusive review approach and applies the previous theoretical models of prescribing behaviour to identify the relational factors. More specifically, the report identifies and uses several valuable perspectives such as the ‘persuasion theory - elaboration likelihood model’, the stimuli–response marketing model’, the ‘agency theory’, the theory of planned behaviour,’ and ‘social power theory,’ in developing an innovative conceptual paradigm. Based on the combination of existing methods and previous models, this paper suggests a new conceptual model of the physician decision-making process. This unique model has the potential for use in further research. PMID:28690701

  5. Distinction between Clock and Time, and a Suggested Experiment with Different Types of Clocks in GPS

    Science.gov (United States)

    Smarandache, Florentin

    2013-03-01

    The clock is an instrument for measuring the time, instrument that may not run perfectly (accurately) under certain conditions (like, say, in strong electromagnetic field, in strong gravitational field, in extremely high or low temperature, pressure, etc.), but this does not mean that time itself runs slower or faster as Einstein's Theory of Relativity asserts. We are referring to an absolute time, i.e. time measured not with respect to ether or non-ether, but with respect to an absolute mathematical reference frame. Several types of clocks could run at a more slowly rate in a moving frame of reference than other types of clocks; it depends on the construction material and functioning principle of each type of clock. Relativists say that ``gravity slows time''. This is incorrect, since actually gravity slows today's types of clocks. And one type of clock is slowed more or less than another type of clock. Not only gravity but other (electric, magnetic, etc.) fields or various medium composition elements or structures may slow or accelerate clocks that are in that medium. The clocks used today in the satellites for the GPS necessitate a correction with respect to the Earth clocks. But in the future, when new types of clocks will be built based on different construction material and functioning principle, the correction of the GPS clocks would be different. In order to make the distinction between ``clock'' and ``time'', we suggest a Experiment # 1 with different types of clocks for the GPS clocks, in order to prove that the resulted dilation and contraction factors are different from those obtained with today's cesium atomic clock.

  6. Mathematical modeling of sustainable synaptogenesis by repetitive stimuli suggests signaling mechanisms in vivo.

    Directory of Open Access Journals (Sweden)

    Hiromu Takizawa

    Full Text Available The mechanisms of long-term synaptic maintenance are a key component to understanding the mechanism of long-term memory. From biological experiments, a hypothesis arose that repetitive stimuli with appropriate intervals are essential to maintain new synapses for periods of longer than a few days. We successfully reproduce the time-course of relative numbers of synapses with our mathematical model in the same conditions as biological experiments, which used Adenosine-3', 5'-cyclic monophosphorothioate, Sp-isomer (Sp-cAMPS as external stimuli. We also reproduce synaptic maintenance responsiveness to intervals of Sp-cAMPS treatment accompanied by PKA activation. The model suggests a possible mechanism of sustainable synaptogenesis which consists of two steps. First, the signal transduction from an external stimulus triggers the synthesis of a new signaling protein. Second, the new signaling protein is required for the next signal transduction with the same stimuli. As a result, the network component is modified from the first network, and a different signal is transferred which triggers the synthesis of another new signaling molecule. We refer to this hypothetical mechanism as network succession. We build our model on the basis of two hypotheses: (1 a multi-step network succession induces downregulation of SSH and COFILIN gene expression, which triggers the production of stable F-actin; (2 the formation of a complex of stable F-actin with Drebrin at PSD is the critical mechanism to achieve long-term synaptic maintenance. Our simulation shows that a three-step network succession is sufficient to reproduce sustainable synapses for a period longer than 14 days. When we change the network structure to a single step network, the model fails to follow the exact condition of repetitive signals to reproduce a sufficient number of synapses. Another advantage of the three-step network succession is that this system indicates a greater tolerance of parameter

  7. A Critical Reflection on a Suggested Return to Aesthetic Experience in Socialist China

    Science.gov (United States)

    Man, Eva Kit Wah

    2001-01-01

    It is said that aestheticians today, including art critics and philosophers, are yearning for some kind of salvation for contemporary art. This salvation would come in the form of a return to aesthetic experience that would act as a foundation enabling resistance to pure discursive reflection and intertextuality. These debates concerning…

  8. Experiments with duckweed-moth systems suggest global warming may reduce rather than promote herbivory

    NARCIS (Netherlands)

    Heide, van Tj.; Roijackers, R.M.M.; Peeters, E.T.H.M.; Nes, van E.H.

    2006-01-01

    1. Wilf & Labandeira (1999)suggested that increased temperatures because of global warming will cause an increase in herbivory by insects. This conclusion was based on the supposed effect of temperature on herbivores but did not consider an effect of temperature on plant growth. 2. We studied

  9. Research in Music Education History: One Historian's Experiences, Perspectives, and Suggestions.

    Science.gov (United States)

    Pemberton, Carol

    1992-01-01

    Discusses the skills, attitudes, and work habits necessary for conducting research in music education. Describes the process used in a historical research study about the impact of Lowell Mason on music in U.S. history. Concludes with six practical suggestions on historical research. (CFR)

  10. Monitoring of scrap loads at Gorzia border checkpoints: A thirty months experience and some suggestions

    International Nuclear Information System (INIS)

    Fabretto, M.

    1999-01-01

    The following topics are highlighted: personnel training, assistance from foreign scrap suppliers, and computerized database. It is suggested that when selecting personnel for this job, major attention should be paid to their attitudes; the personnel should be given very good training, teaching them also how to make controls manually; expert physicist' support should be available within a very short time; each monitoring checkpoint should have its local electronic database; periodical exchange and updating of information should be practised on the standardization of methods of detection, of levels of attention and alarm, of statistics among the people in charge of EU and non-EU countries. (P.A.)

  11. Endovenous simulated laser experiments at 940 nm and 1470 nm suggest wavelength-independent temperature profiles.

    Science.gov (United States)

    van den Bos, R R; van Ruijven, P W M; van der Geld, C W M; van Gemert, M J C; Neumann, H A M; Nijsten, T

    2012-07-01

    EVLA has proven to be very successful, but the optimum methods for energy delivery have still not been clarified. A better understanding of the mechanism of action may contribute to achieving a consensus on the best laser method and the most effective use of laser parameters, resulting in optimal clinical outcomes, maintaining high success rates with minimal adverse events. The aim of this study is to assess the impact of wavelength, pullback speed and power level on the endovenous temperature profile in an experimental setting. In an experimental setting, temperature measurements were performed using thermocouples. The experimental set-up consisted of a transparent box in which a glass tube was fixed. Different laser parameters (wavelength and power) and 2 different pullback speeds (2 and 5 mm/s) were used. Thermocouples were placed at different distances from the fiber tip. Validity of the experimental setting was assessed by performing the same temperature measurements using a stripped varicose vein. The maximal temperature rise and the time span that the temperature was above collagen denaturation temperature were measured. The experiments showed that decreasing the pullback speed (2 mm/s) and increasing the power (up to 14 W) both cause higher maximal temperature and a longer time above the temperature for collagen denaturation. The use of different laser wavelengths (940 or 1470 nm) did not influence the temperature profile. The results of our experiments show that wavelength on its own has not been demonstrated to be an important parameter to influence the temperature profile. Copyright © 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  12. MARKETING MODELS APPLICATION EXPERIENCE

    Directory of Open Access Journals (Sweden)

    A. Yu. Rymanov

    2011-01-01

    Full Text Available Marketing models are used for the assessment of such marketing elements as sales volume, market share, market attractiveness, advertizing costs, product pushing and selling, profit, profitableness. Classification of buying process decision taking models is presented. SWOT- and GAPbased models are best for selling assessments. Lately, there is a tendency to transfer from the assessment on the ba-sis of financial indices to that on the basis of those non-financial. From the marketing viewpoint, most important are long-term company activities and consumer drawingmodels as well as market attractiveness operative models.

  13. Modelling Urban Experiences

    DEFF Research Database (Denmark)

    Jantzen, Christian; Vetner, Mikael

    2008-01-01

    How can urban designers develop an emotionally satisfying environment not only for today's users but also for coming generations? Which devices can they use to elicit interesting and relevant urban experiences? This paper attempts to answer these questions by analyzing the design of Zuidas, a new...

  14. Experience from implementing international standards in national emergency response planning national adjustments and suggestions for improvements

    International Nuclear Information System (INIS)

    Naadland Holo, E.

    2003-01-01

    Full text: A process has been going on for some time in Norway to establish a harmonized background for emergency response planning for any kind of nuclear or radiological accident. The national emergency preparedness organisation with the crisis committee for nuclear accident, consisting of representatives from civil defence, defence, police-, health-, and food control authorities, has the authority to implement countermeasures to protect health, environment and national interests in case of an accident or in case of nuclear terrorism. However, in an early phase, the response plans need to be fully harmonized to ensure that every operational level knows their responsibility and the responsibilities of others. Our intention is to implement the IAEA standard 'preparedness and response for a nuclear or radiological emergency'. We believe this will simplify national and international communication and also simplify the crisis management if an accident occurs. In revising the national plans, and also the planning basis at regional and local level, as well as the planning basis for response to accidents at national nuclear facilities and in connection with arrival of nuclear submarines in Norwegian harbours, we have seen the need to make national adjustments to the international standards. In addition to the standard, there exist several other processes and routines for reporting different kinds of incidents. We have seen a need to coordinate this internally at the competent authority to simplify the routines. This paper will focus on the challenges we have met, our national solutions and some suggestions for simplification. National adjustments to the international standard. - Firstly, the threat categorization needs to be adjusted. First of all, we do not have nuclear power plants in Norway. In the aftermath of 11 September 2001 we also have focused more an the potential for nuclear terrorism. Nuclear terrorism is unlikely but puts up some new requirements in the

  15. Modeling Choice and Valuation in Decision Experiments

    Science.gov (United States)

    Loomes, Graham

    2010-01-01

    This article develops a parsimonious descriptive model of individual choice and valuation in the kinds of experiments that constitute a substantial part of the literature relating to decision making under risk and uncertainty. It suggests that many of the best known "regularities" observed in those experiments may arise from a tendency for…

  16. Simulation - modeling - experiment; Simulation - modelisation - experience

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    After two workshops held in 2001 on the same topics, and in order to make a status of the advances in the domain of simulation and measurements, the main goals proposed for this workshop are: the presentation of the state-of-the-art of tools, methods and experiments in the domains of interest of the Gedepeon research group, the exchange of information about the possibilities of use of computer codes and facilities, about the understanding of physical and chemical phenomena, and about development and experiment needs. This document gathers 18 presentations (slides) among the 19 given at this workshop and dealing with: the deterministic and stochastic codes in reactor physics (Rimpault G.); MURE: an evolution code coupled with MCNP (Meplan O.); neutronic calculation of future reactors at EdF (Lecarpentier D.); advance status of the MCNP/TRIO-U neutronic/thermal-hydraulics coupling (Nuttin A.); the FLICA4/TRIPOLI4 thermal-hydraulics/neutronics coupling (Aniel S.); methods of disturbances and sensitivity analysis of nuclear data in reactor physics, application to VENUS-2 experimental reactor (Bidaud A.); modeling for the reliability improvement of an ADS accelerator (Biarotte J.L.); residual gas compensation of the space charge of intense beams (Ben Ismail A.); experimental determination and numerical modeling of phase equilibrium diagrams of interest in nuclear applications (Gachon J.C.); modeling of irradiation effects (Barbu A.); elastic limit and irradiation damage in Fe-Cr alloys: simulation and experiment (Pontikis V.); experimental measurements of spallation residues, comparison with Monte-Carlo simulation codes (Fallot M.); the spallation target-reactor coupling (Rimpault G.); tools and data (Grouiller J.P.); models in high energy transport codes: status and perspective (Leray S.); other ways of investigation for spallation (Audoin L.); neutrons and light particles production at intermediate energies (20-200 MeV) with iron, lead and uranium targets (Le Colley F

  17. Design Studies Suggested by an Abstract Model for a Medical Information System

    Science.gov (United States)

    Cox, J. R.; Kimura, T. D.; Moore, P.; Gillett, W.; Stucki, M. J.

    1980-01-01

    We have developed a formal model of a database system that is unusual in that it has the ability to represent information about its own structure and to insure semantic consistency. The model distinguishes general laws from instances of events and objects, but many of its mechanisms serve both categories of information. The model forms a substrate upon which an information structure appropriate to neonatology is being developed. Some example queries are shown and a design study for an associative memory suggested by the model is described briefly.

  18. Twenty Careers and Classroom Experiences for Teaching Science. Includes: Job Descriptions, Teaching Suggestions and Answers, Work Sheets.

    Science.gov (United States)

    Ondrake, Greg

    Part 1 of this teacher's guide contains job descriptions, teaching suggestions/answers, and worksheets for twenty careers and classroom experiences which are designed to be used in teaching science. The following twenty careers are covered: meteorologist, geologist, musical instrument maker/repairman, opthalmologist, astronomer, paint chemist,…

  19. Suggestions for planning a migration-monitoring network based on the experience of establishing and operating the maps program

    Science.gov (United States)

    David F. DeSante

    2005-01-01

    Based on the experience of creating and implementing the Monitoring Avian Productivity and Survivorship (MAPS) program, I suggest that, to be successful, a migration-monitoring network must: (1) provide strong justification for the data it proposes to collect; (2) provide direct links between those monitoring data and both research and management goals; (3) provide...

  20. Mentoring for junior medical faculty: Existing models and suggestions for low-resource settings.

    Science.gov (United States)

    Menon, Vikas; Muraleedharan, Aparna; Bhat, Ballambhattu Vishnu

    2016-02-01

    Globally, there is increasing recognition about the positive benefits and impact of mentoring on faculty retention rates, career satisfaction and scholarly output. However, emphasis on research and practice of mentoring is comparatively meagre in low and middle income countries. In this commentary, we critically examine two existing models of mentorship for medical faculty and offer few suggestions for an integrated hybrid model that can be adapted for use in low resource settings. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. The database for reaching experiments and models.

    Directory of Open Access Journals (Sweden)

    Ben Walker

    Full Text Available Reaching is one of the central experimental paradigms in the field of motor control, and many computational models of reaching have been published. While most of these models try to explain subject data (such as movement kinematics, reaching performance, forces, etc. from only a single experiment, distinct experiments often share experimental conditions and record similar kinematics. This suggests that reaching models could be applied to (and falsified by multiple experiments. However, using multiple datasets is difficult because experimental data formats vary widely. Standardizing data formats promises to enable scientists to test model predictions against many experiments and to compare experimental results across labs. Here we report on the development of a new resource available to scientists: a database of reaching called the Database for Reaching Experiments And Models (DREAM. DREAM collects both experimental datasets and models and facilitates their comparison by standardizing formats. The DREAM project promises to be useful for experimentalists who want to understand how their data relates to models, for modelers who want to test their theories, and for educators who want to help students better understand reaching experiments, models, and data analysis.

  2. A trophic model of fringing coral reefs in Nanwan Bay, southern Taiwan suggests overfishing.

    Science.gov (United States)

    Liu, Pi-Jen; Shao, Kwang-Tsao; Jan, Rong-Quen; Fan, Tung-Yung; Wong, Saou-Lien; Hwang, Jiang-Shiou; Chen, Jen-Ping; Chen, Chung-Chi; Lin, Hsing-Juh

    2009-09-01

    Several coral reefs of Nanwan Bay, Taiwan have recently undergone shifts to macroalgal or sea anemone dominance. Thus, a mass-balance trophic model was constructed to analyze the structure and functioning of the food web. The fringing reef model was comprised of 18 compartments, with the highest trophic level of 3.45 for piscivorous fish. Comparative analyses with other reef models demonstrated that Nanwan Bay was similar to reefs with high fishery catches. While coral biomass was not lower, fish biomass was lower than those of reefs with high catches. Consequently, the sums of consumption and respiratory flows and total system throughput were also decreased. The Nanwan Bay model potentially suggests an overfished status in which the mean trophic level of the catch, matter cycling, and trophic transfer efficiency are extremely reduced.

  3. 'Cape capture': Geologic data and modeling results suggest the holocene loss of a Carolina Cape

    Science.gov (United States)

    Thieler, E.R.; Ashton, A.D.

    2011-01-01

    For more than a century, the origin and evolution of the set of cuspate forelands known as the Carolina Capes-Hatteras, Lookout, Fear, and Romain-off the eastern coast of the United States have been discussed and debated. The consensus conceptual model is not only that these capes existed through much or all of the Holocene transgression, but also that their number has not changed. Here we describe bathymetric, lithologic, seismic, and chronologic data that suggest another cape may have existed between Capes Hatteras and Lookout during the early to middle Holocene. This cape likely formed at the distal end of the Neuse-Tar-Pamlico fiuvial system during the early Holocene transgression, when this portion of the shelf was fiooded ca. 9 cal (calibrated) kyr B.P., and was probably abandoned by ca. 4 cal kyr B.P., when the shoreline attained its present general configuration. Previously proposed mechanisms for cape formation suggest that the large-scale, rhythmic pattern of the Carolina Capes arose from a hydrodynamic template or the preexisting geologic framework. Numerical modeling, however, suggests that the number and spacing of capes can be dynamic, and that a coast can self-organize in response to a high-angle-wave instability in shoreline shape. In shoreline evolution model simulations, smaller cuspate forelands are subsumed by larger neighbors over millennial time scales through a process of 'cape capture.' The suggested former cape in Raleigh Bay represents the first interpreted geological evidence of dynamic abandonment suggested by the self-organization hypothesis. Cape capture may be a widespread process in coastal environments with large-scale rhythmic shoreline features; its preservation in the sedimentary record will vary according to geologic setting, physical processes, and sea-level history. ?? 2011 Geological Society of America.

  4. Authority Delegation in Boyerahmad Health Centers through Model to Combine Suggestions System and Delphi Method 2012

    Directory of Open Access Journals (Sweden)

    M Momeninezhad

    2013-11-01

    Full Text Available Background & aim: Authority delegation means to transmit part of organization`s manager and leader`s special authorities and executive duties, regardless its root to subordinates and heads of units and related offices to speed up implementing affairs and organizational purposes quickly and on time. The purpose of this study was to inspect authority delegation in health centers of Boyerahmad district through using model to combine suggestions (to identify process and Delphi method (expert`s opinions . Methods: This cross-sectional study was implemented in two stages at first stage, research community was authorities of Boyerahmad health centers (58 persons, their suggestions about requested processes to delegate were gathered by total count through open questionnaires and in second stage, which was Delphi, suggestions gathered from previous stage judged by 30 experts. Data of both stages analyzed by help of Chi-square, correlation coefficient tests. Results: Findings showed that 73.85% of suggestions were able to be delegated, based on expert`s opinion. 40% of suggestions were in domain of official, 36.92% financial and 23.08% hygienic. 88% less than 6 years management background. 20.69% had no academic studies and only 27% were general physicians. Conclusion: By participation of environmental management levels, several processes may be specified and identify cases which are possible to delegate them executively using Delphi (expert`s opinion and this model can be used as a trust worthy method to delegate authority for decentralization. Key words: Participation Management, Health centers, Authority delegation

  5. Computational modelling suggests good, bad and ugly roles of glycosaminoglycans in arterial wall mechanics and mechanobiology

    Science.gov (United States)

    Roccabianca, S.; Bellini, C.; Humphrey, J. D.

    2014-01-01

    The medial layer of large arteries contains aggregates of the glycosaminoglycan hyaluronan and the proteoglycan versican. It is increasingly thought that these aggregates play important mechanical and mechanobiological roles despite constituting only a small fraction of the normal arterial wall. In this paper, we offer a new hypothesis that normal aggregates of hyaluronan and versican pressurize the intralamellar spaces, and thereby put into tension the radial elastic fibres that connect the smooth muscle cells to the elastic laminae, which would facilitate mechanosensing. This hypothesis is supported by novel computational simulations using two complementary models, a mechanistically based finite-element mixture model and a phenomenologically motivated continuum hyperelastic model. That is, the simulations suggest that normal aggregates of glycosaminoglycans/proteoglycans within the arterial media may play equally important roles in supporting (i.e. a structural role) and sensing (i.e. an instructional role) mechanical loads. Additional simulations suggest further, however, that abnormal increases in these aggregates, either distributed or localized, may over-pressurize the intralamellar units. We submit that these situations could lead to compromised mechanosensing, anoikis and/or reduced structural integrity, each of which represent fundamental aspects of arterial pathologies seen, for example, in hypertension, ageing and thoracic aortic aneurysms and dissections. PMID:24920112

  6. A Website to Improve Asthma Care by Suggesting Patient Questions for Physicians: Qualitative Analysis of User Experiences

    Science.gov (United States)

    Sciamanna, Christopher N; Blanch, Danielle C; Mui, Sarah; Lawless, Heather; Manocchia, Michael; Rosen, Rochelle K; Pietropaoli, Anthony

    2007-01-01

    Background Asthma is one of the most prevalent chronic conditions in the United Sates, yet despite the existence of national guidelines, nearly three fourths of patients with asthma do not have adequate control and clinical adherence to guidelines is low. While there are many reasons for this, physician inertia with respect to treatment change is partly to blame. Research suggests that patients who ask for specific tests and treatments are more likely to receive them. Objectives This study investigated the impact and experience of using an interactive patient website designed to give patients individual feedback about their condition and to suggest tailored questions for patients to ask their physician. The website was designed to be used prior to a physician visit, to increase the likelihood that patients would receive recommended tests and treatments. Methods A total of 37 adult patients with asthma participated in semi-structured telephone interviews aimed at eliciting information about their experiences with the website. Transcripts were coded using qualitative data analysis techniques and software. Themes were developed from subsets of codes generated through the analysis. In addition, 26 physicians were surveyed regarding their impressions of the website. Results Opportunities exist for improving website feedback, although the majority of both patient and physician respondents held favorable opinions about the site. Two major themes emerged regarding patients’ experiences with the website. First, many patients who used the website had a positive shift in their attitudes regarding interactions with their physicians. Second, use of the website prompted patients to become more actively involved in their asthma care. No patient reported any negative experiences as a result of using the website. Physicians rated the website positively. Conclusions Patients perceived that the interactive website intervention improved communication and interaction with their

  7. Atmospheric CO2 observations and models suggest strong carbon uptake by forests in New Zealand

    Science.gov (United States)

    Steinkamp, Kay; Mikaloff Fletcher, Sara E.; Brailsford, Gordon; Smale, Dan; Moore, Stuart; Keller, Elizabeth D.; Baisden, W. Troy; Mukai, Hitoshi; Stephens, Britton B.

    2017-01-01

    A regional atmospheric inversion method has been developed to determine the spatial and temporal distribution of CO2 sinks and sources across New Zealand for 2011-2013. This approach infers net air-sea and air-land CO2 fluxes from measurement records, using back-trajectory simulations from the Numerical Atmospheric dispersion Modelling Environment (NAME) Lagrangian dispersion model, driven by meteorology from the New Zealand Limited Area Model (NZLAM) weather prediction model. The inversion uses in situ measurements from two fixed sites, Baring Head on the southern tip of New Zealand's North Island (41.408° S, 174.871° E) and Lauder from the central South Island (45.038° S, 169.684° E), and ship board data from monthly cruises between Japan, New Zealand, and Australia. A range of scenarios is used to assess the sensitivity of the inversion method to underlying assumptions and to ensure robustness of the results. The results indicate a strong seasonal cycle in terrestrial land fluxes from the South Island of New Zealand, especially in western regions covered by indigenous forest, suggesting higher photosynthetic and respiratory activity than is evident in the current a priori land process model. On the annual scale, the terrestrial biosphere in New Zealand is estimated to be a net CO2 sink, removing 98 (±37) Tg CO2 yr-1 from the atmosphere on average during 2011-2013. This sink is much larger than the reported 27 Tg CO2 yr-1 from the national inventory for the same time period. The difference can be partially reconciled when factors related to forest and agricultural management and exports, fossil fuel emission estimates, hydrologic fluxes, and soil carbon change are considered, but some differences are likely to remain. Baseline uncertainty, model transport uncertainty, and limited sensitivity to the northern half of the North Island are the main contributors to flux uncertainty.

  8. Low modeled ozone production suggests underestimation of precursor emissions (especially NOx in Europe

    Directory of Open Access Journals (Sweden)

    E. Oikonomakis

    2018-02-01

    (where both NOx and VOC emissions are increased leads to a better model performance. Although increasing only the traffic NOx emissions by a factor of 4 gave very similar results to the doubling of all NOx emissions, the first scenario is more consistent with the uncertainties reported by other studies than the latter, suggesting that high uncertainties in NOx emissions might originate mainly from the road-transport sector rather than from other sectors. The impact of meteorology was examined with three sensitivity tests: (i increased surface temperature by 4 °C, (ii reduced wind speed by 50 % and (iii doubled wind speed. The first two scenarios led to a consistent increase in all surface ozone mixing ratios, thus improving the model performance for the high ozone values but significantly degrading it for the low ozone values, while the third scenario had exactly the opposite effects. Overall, the modeled ozone is predicted to be more sensitive to its precursor emissions (especially traffic NOx and therefore their uncertainties, which seem to be responsible for the model underestimation of the observed high ozone mixing ratios and ozone production.

  9. Adsorption of amino acids and nucleic acid bases onto minerals: a few suggestions for prebiotic chemistry experiments

    Science.gov (United States)

    Zaia, Dimas A. M.

    2012-10-01

    Amino acids and nucleic acid bases are very important for the living organisms. Thus, their protection from decomposition, selection, pre-concentration and formation of biopolymers are important issues for understanding the origin of life on the Earth. Minerals could have played all of these roles. This paper discusses several aspects involving the adsorption of amino acids and nucleic acid bases onto minerals under conditions that could have been found on the prebiotic Earth; in particular, we recommend the use of minerals, amino acids, nucleic acid bases and seawater ions in prebiotic chemistry experiments. Several experiments involving amino acids, nucleic acid bases, minerals and seawater ions are also suggested, including: (a) using well-characterized minerals and the standardization of the mineral synthesis methods; (b) using primary chondrite minerals (olivine, pyroxene, etc.) and clays modified with metals (Cu, Fe, Ni, Mo, Zn, etc.); (c) determination of the possible products of decomposition due to interactions of amino acids and nucleic acid bases with minerals; (d) using minerals with more organophilic characteristics; (e) using seawaters with different concentrations of ions (i.e. Na+, Ca2+, Mg2+, SO4 2- and Cl-) (f) using non-protein amino acids (AIB, α-ABA, β-ABA, γ-ABA and β-Ala and g) using nucleic acid bases other than adenine, thymine, uracil and cytosine. These experiments could be useful to clarify the role played by minerals in the origin of life on the Earth.

  10. The Nature of Scatter at the DARHT Facility and Suggestions for Improved Modeling of DARHT Facility

    Energy Technology Data Exchange (ETDEWEB)

    Morneau, Rachel Anne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Klasky, Marc Louis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-09

    The U.S. Stockpile Stewardship Program [1] is designed to sustain and evaluate the nuclear weapons stockpile while foregoing underground nuclear tests. The maintenance of a smaller, aging U.S. nuclear weapons stockpile without underground testing requires complex computer calculations [14]. These calculations in turn need to be verified and benchmarked [14]. A wide range of research facilities have been used to test and evaluate nuclear weapons while respecting the Comprehensive Nuclear Test-Ban Treaty (CTBT) [2]. Some of these facilities include the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, the Z machine at Sandia National Laboratories, and the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory. This research will focus largely on DARHT (although some information from Cygnus and the Los Alamos Microtron may be used in this research) by modeling it and comparing to experimental data. DARHT is an electron accelerator that employs high-energy flash x-ray sources for imaging hydro-tests. This research proposes to address some of the issues crucial to understanding DARHT Axis II and the analysis of the radiographic images produced. Primarily, the nature of scatter at DARHT will be modeled and verified with experimental data. It will then be shown that certain design decisions can be made to optimize the scatter field for hydrotest experiments. Spectral effects will be briefly explored to determine if there is any considerable effect on the density reconstruction caused by changes in the energy spectrum caused by target changes. Finally, a generalized scatter model will be made using results from MCNP that can be convolved with the direct transmission of an object to simulate the scatter of that object at the detector plane. The region in which with this scatter model is appropriate will be explored.

  11. Low modeled ozone production suggests underestimation of precursor emissions (especially NOx) in Europe

    Science.gov (United States)

    Oikonomakis, Emmanouil; Aksoyoglu, Sebnem; Ciarelli, Giancarlo; Baltensperger, Urs; Prévôt, André Stephan Henry

    2018-02-01

    the latter, suggesting that high uncertainties in NOx emissions might originate mainly from the road-transport sector rather than from other sectors. The impact of meteorology was examined with three sensitivity tests: (i) increased surface temperature by 4 °C, (ii) reduced wind speed by 50 % and (iii) doubled wind speed. The first two scenarios led to a consistent increase in all surface ozone mixing ratios, thus improving the model performance for the high ozone values but significantly degrading it for the low ozone values, while the third scenario had exactly the opposite effects. Overall, the modeled ozone is predicted to be more sensitive to its precursor emissions (especially traffic NOx) and therefore their uncertainties, which seem to be responsible for the model underestimation of the observed high ozone mixing ratios and ozone production.

  12. Mentoring in Gifted Student’s Education and a Model Suggestion

    Directory of Open Access Journals (Sweden)

    Lutfu Cakir

    2016-01-01

    Full Text Available The purpose of this study is to examine the mentoring process in the education of gifted students and to develop a model applicable for the Turkish Educational System. The data of the study were collected through a literature review and focus group interviews. The study was conducted on one public and one private education institution for gifted students in Istanbul, Turkey. Purposeful sampling method was used in this study. A total of nine group interviews were carried out on 43 shareholders, the administrators, teachers, parents and student sub-groups, of the institutions in the sample group. The interviews were recorded and the recordings transcribed and analyzed through content analysis. As a result of the study, the establishment of a mentoring model was suggested under the Ministry of National Education, General Directorate of Special Education Guidance and Counseling Services, Department of Special Talents Development and issues such as model development, mentor and service area selection, matching, system operation and feedback were examined in detail.

  13. Bridging experiments, models and simulations

    DEFF Research Database (Denmark)

    Carusi, Annamaria; Burrage, Kevin; Rodríguez, Blanca

    2012-01-01

    understanding of living organisms and also how they can reduce, replace, and refine animal experiments. A fundamental requirement to fulfill these expectations and achieve the full potential of computational physiology is a clear understanding of what models represent and how they can be validated. The present...... of biovariability; 2) testing and developing robust techniques and tools as a prerequisite to conducting physiological investigations; 3) defining and adopting standards to facilitate the interoperability of experiments, models, and simulations; 4) and understanding physiological validation as an iterative process...... that contributes to defining the specific aspects of cardiac electrophysiology the MSE system targets, rather than being only an external test, and that this is driven by advances in experimental and computational methods and the combination of both....

  14. Debris flows: Experiments and modelling

    Science.gov (United States)

    Turnbull, Barbara; Bowman, Elisabeth T.; McElwaine, Jim N.

    2015-01-01

    Debris flows and debris avalanches are complex, gravity-driven currents of rock, water and sediments that can be highly mobile. This combination of component materials leads to a rich morphology and unusual dynamics, exhibiting features of both granular materials and viscous gravity currents. Although extreme events such as those at Kolka Karmadon in North Ossetia (2002) [1] and Huascarán (1970) [2] strongly motivate us to understand how such high levels of mobility can occur, smaller events are ubiquitous and capable of endangering infrastructure and life, requiring mitigation. Recent progress in modelling debris flows has seen the development of multiphase models that can start to provide clues of the origins of the unique phenomenology of debris flows. However, the spatial and temporal variations that debris flows exhibit make this task challenging and laboratory experiments, where boundary and initial conditions can be controlled and reproduced, are crucial both to validate models and to inspire new modelling approaches. This paper discusses recent laboratory experiments on debris flows and the state of the art in numerical models.

  15. Coalescent Modelling Suggests Recent Secondary-Contact of Cryptic Penguin Species.

    Science.gov (United States)

    Grosser, Stefanie; Burridge, Christopher P; Peucker, Amanda J; Waters, Jonathan M

    2015-01-01

    Molecular genetic analyses present powerful tools for elucidating demographic and biogeographic histories of taxa. Here we present genetic evidence showing a dynamic history for two cryptic lineages within Eudyptula, the world's smallest penguin. Specifically, we use a suite of genetic markers to reveal that two congeneric taxa ('Australia' and 'New Zealand') co-occur in southern New Zealand, with only low levels of hybridization. Coalescent modelling suggests that the Australian little penguin only recently expanded into southern New Zealand. Analyses conducted under time-dependent molecular evolutionary rates lend support to the hypothesis of recent anthropogenic turnover, consistent with shifts detected in several other New Zealand coastal vertebrate taxa. This apparent turnover event highlights the dynamic nature of the region's coastal ecosystem.

  16. Microarray and bioinformatic analyses suggest models for carbon metabolism in the autotroph Acidithiobacillus ferrooxidans

    Energy Technology Data Exchange (ETDEWEB)

    C. Appia-ayme; R. Quatrini; Y. Denis; F. Denizot; S. Silver; F. Roberto; F. Veloso; J. Valdes; J. P. Cardenas; M. Esparza; O. Orellana; E. Jedlicki; V. Bonnefoy; D. Holmes

    2006-09-01

    Acidithiobacillus ferrooxidans is a chemolithoautotrophic bacterium that uses iron or sulfur as an energy and electron source. Bioinformatic analysis was used to identify putative genes and potential metabolic pathways involved in CO2 fixation, 2P-glycolate detoxification, carboxysome formation and glycogen utilization in At. ferrooxidans. Microarray transcript profiling was carried out to compare the relative expression of the predicted genes of these pathways when the microorganism was grown in the presence of iron versus sulfur. Several gene expression patterns were confirmed by real-time PCR. Genes for each of the above predicted pathways were found to be organized into discrete clusters. Clusters exhibited differential gene expression depending on the presence of iron or sulfur in the medium. Concordance of gene expression within each cluster, suggested that they are operons Most notably, clusters of genes predicted to be involved in CO2 fixation, carboxysome formation, 2P-glycolate detoxification and glycogen biosynthesis were up-regulated in sulfur medium, whereas genes involved in glycogen utilization were preferentially expressed in iron medium. These results can be explained in terms of models of gene regulation that suggest how A. ferrooxidans can adjust its central carbon management to respond to changing environmental conditions.

  17. A cervid vocal fold model suggests greater glottal efficiency in calling at high frequencies.

    Directory of Open Access Journals (Sweden)

    Ingo R Titze

    2010-08-01

    Full Text Available Male Rocky Mountain elk (Cervus elaphus nelsoni produce loud and high fundamental frequency bugles during the mating season, in contrast to the male European Red Deer (Cervus elaphus scoticus who produces loud and low fundamental frequency roaring calls. A critical step in understanding vocal communication is to relate sound complexity to anatomy and physiology in a causal manner. Experimentation at the sound source, often difficult in vivo in mammals, is simulated here by a finite element model of the larynx and a wave propagation model of the vocal tract, both based on the morphology and biomechanics of the elk. The model can produce a wide range of fundamental frequencies. Low fundamental frequencies require low vocal fold strain, but large lung pressure and large glottal flow if sound intensity level is to exceed 70 dB at 10 m distance. A high-frequency bugle requires both large muscular effort (to strain the vocal ligament and high lung pressure (to overcome phonation threshold pressure, but at least 10 dB more intensity level can be achieved. Glottal efficiency, the ration of radiated sound power to aerodynamic power at the glottis, is higher in elk, suggesting an advantage of high-pitched signaling. This advantage is based on two aspects; first, the lower airflow required for aerodynamic power and, second, an acoustic radiation advantage at higher frequencies. Both signal types are used by the respective males during the mating season and probably serve as honest signals. The two signal types relate differently to physical qualities of the sender. The low-frequency sound (Red Deer call relates to overall body size via a strong relationship between acoustic parameters and the size of vocal organs and body size. The high-frequency bugle may signal muscular strength and endurance, via a 'vocalizing at the edge' mechanism, for which efficiency is critical.

  18. Models for leprosy. An appraisal of graphic representations of the "spectrum" concept as models and a suggestion for a catastrophe theory model for leprosy.

    Science.gov (United States)

    Srinivasan, H

    1984-09-01

    Graphic representations of the spectrum concept of leprosy are examined in some detail as models for this disease. This reveals that this concept is somewhat inadequate and that the spectrum metaphor may itself be inappropriate because, by its very linearity of logic, it may not be able to depict the nonlinear behavior of leprosy properly. The assumptions underlying this concept and their logical consequences, brought out by the graphic representations, include an invariable relation between CMI and BI, identity of one type of leprosy with one specific level of CMI, a fixed sequence of types, and the consequent impossibility of skipping the sequence. However, our experience with leprosy does not bear out these assumptions. Further, development and progress of leprosy from a normal (nonleprous) state cannot be represented in these models. A search for alternative conceptual models therefore appears reasonable and even necessary. The catastrophe theory (a branch of topology in mathematics) describes a number of models for explaining how continuous causes could produce sudden or discontinuous changes. Of the various catastrophe theory models available, the relatively simple "cusp" model appears capable of application to leprosy. This model, as applied here, requires two control factors (identified tentatively as the amount of dead bacilli and the amount of living bacilli or their indicators) and one pattern of behavior, identified as progress towards limited or extensive disease. This model suggests under what conditions leprosy will change from one type to another and whether that will happen gradually or suddenly. It also suggests that for certain values of control factors the disease may manifest in one of two forms of borderline leprosy, and that lesions very similar to start with can progress to quite different states under similar conditions of change. The behavior of leprosy agrees more or less with that suggested by this model. The cusp model thus seems to: a

  19. Evidence Suggesting a Role of Iron in a Mouse Model of Nephrogenic Systemic Fibrosis.

    Directory of Open Access Journals (Sweden)

    Chhanda Bose

    Full Text Available Nephrogenic systemic fibrosis is associated with gadolinium contrast exposure in patients with reduced kidney function and carries high morbidity and mortality. We have previously demonstrated that gadolinium contrast agents induce in vivo systemic iron mobilization and in vitro differentiation of peripheral blood mononuclear cells into ferroportin (iron exporter-expressing fibrocytic cells. In the present study we examined the role of iron in a mouse model of nephrogenic systemic fibrosis. Chronic kidney disease was induced in 8-week-old male Balb/C mice with a two-step 5/6 nephrectomy surgery. Five groups of mice were studied: control (n = 5, sham surgery control (n = 5, chronic kidney disease control (n = 4, chronic kidney disease injected with 0.5 mmol/kg body weight of Omniscan 3 days per week, for a total of 10 injections (n = 8, and chronic kidney disease with Omniscan plus deferiprone, 125 mg/kg, in drinking water (n = 9. Deferiprone was continued for 16 weeks until the end of the experiment. Mice with chronic kidney disease injected with Omniscan developed skin changes characteristic of nephrogenic systemic fibrosis including hair loss, reddening, ulceration, and skin tightening by 10 to 16 weeks. Histopathological sections demonstrated dermal fibrosis with increased skin thickness (0.25±0.06 mm, sham; 0.34±+0.3 mm, Omniscan-injected. Additionally, we observed an increase in tissue infiltration of ferroportin-expressing, fibrocyte-like cells accompanied by tissue iron accumulation in the skin of the Omniscan-treated mice. The deferiprone-treated group had significantly decreased skin thickness (p<0.05 and significantly decreased dermal fibrosis compared to the Omniscan-only group. In addition, iron chelation prevented tissue infiltration of ferroportin-expressing, fibrocyte-like cells. Our in vitro experiments demonstrated that exposure to Omniscan resulted in the release of catalytic iron and this was prevented by the iron chelator

  20. Rate control management of atrial fibrillation: may a mathematical model suggest an ideal heart rate?

    Directory of Open Access Journals (Sweden)

    Matteo Anselmino

    Full Text Available Despite the routine prescription of rate control therapy for atrial fibrillation (AF, clinical evidence demonstrating a heart rate target is lacking. Aim of the present study was to run a mathematical model simulating AF episodes with a different heart rate (HR to predict hemodynamic parameters for each situation.The lumped model, representing the pumping heart together with systemic and pulmonary circuits, was run to simulate AF with HR of 50, 70, 90, 110 and 130 bpm, respectively.Left ventricular pressure increased by 57%, from 33.92±37.56 mmHg to 53.15±47.56 mmHg, and mean systemic arterial pressure increased by 27%, from 82.66±14.04 mmHg to 105.3±7.6 mmHg, at the 50 and 130 bpm simulations, respectively. Stroke volume (from 77.45±8.50 to 39.09±8.08 mL, ejection fraction (from 61.10±4.40 to 39.32±5.42% and stroke work (SW, from 0.88±0.04 to 0.58±0.09 J decreased by 50, 36 and 34%, at the 50 and 130 bpm simulations, respectively. In addition, oxygen consumption indexes (rate pressure product - RPP, tension time index per minute - TTI/min, and pressure volume area per minute - PVA/min increased from the 50 to the 130 bpm simulation, respectively, by 186% (from 5598±1939 to 15995±3219 mmHg/min, 56% (from 2094±265 to 3257±301 mmHg s/min and 102% (from 57.99±17.90 to 117.4±26.0 J/min. In fact, left ventricular efficiency (SW/PVA decreased from 80.91±2.91% at 50 bpm to 66.43±3.72% at the 130 bpm HR simulation.Awaiting compulsory direct clinical evidences, the present mathematical model suggests that lower HRs during permanent AF relates to improved hemodynamic parameters, cardiac efficiency, and lower oxygen consumption.

  1. Rate control management of atrial fibrillation: may a mathematical model suggest an ideal heart rate?

    Science.gov (United States)

    Anselmino, Matteo; Scarsoglio, Stefania; Camporeale, Carlo; Saglietto, Andrea; Gaita, Fiorenzo; Ridolfi, Luca

    2015-01-01

    Despite the routine prescription of rate control therapy for atrial fibrillation (AF), clinical evidence demonstrating a heart rate target is lacking. Aim of the present study was to run a mathematical model simulating AF episodes with a different heart rate (HR) to predict hemodynamic parameters for each situation. The lumped model, representing the pumping heart together with systemic and pulmonary circuits, was run to simulate AF with HR of 50, 70, 90, 110 and 130 bpm, respectively. Left ventricular pressure increased by 57%, from 33.92±37.56 mmHg to 53.15±47.56 mmHg, and mean systemic arterial pressure increased by 27%, from 82.66±14.04 mmHg to 105.3±7.6 mmHg, at the 50 and 130 bpm simulations, respectively. Stroke volume (from 77.45±8.50 to 39.09±8.08 mL), ejection fraction (from 61.10±4.40 to 39.32±5.42%) and stroke work (SW, from 0.88±0.04 to 0.58±0.09 J) decreased by 50, 36 and 34%, at the 50 and 130 bpm simulations, respectively. In addition, oxygen consumption indexes (rate pressure product - RPP, tension time index per minute - TTI/min, and pressure volume area per minute - PVA/min) increased from the 50 to the 130 bpm simulation, respectively, by 186% (from 5598±1939 to 15995±3219 mmHg/min), 56% (from 2094±265 to 3257±301 mmHg s/min) and 102% (from 57.99±17.90 to 117.4±26.0 J/min). In fact, left ventricular efficiency (SW/PVA) decreased from 80.91±2.91% at 50 bpm to 66.43±3.72% at the 130 bpm HR simulation. Awaiting compulsory direct clinical evidences, the present mathematical model suggests that lower HRs during permanent AF relates to improved hemodynamic parameters, cardiac efficiency, and lower oxygen consumption.

  2. Genomic survey, gene expression analysis and structural modeling suggest diverse roles of DNA methyltransferases in legumes.

    Directory of Open Access Journals (Sweden)

    Rohini Garg

    Full Text Available DNA methylation plays a crucial role in development through inheritable gene silencing. Plants possess three types of DNA methyltransferases (MTases, namely Methyltransferase (MET, Chromomethylase (CMT and Domains Rearranged Methyltransferase (DRM, which maintain methylation at CG, CHG and CHH sites. DNA MTases have not been studied in legumes so far. Here, we report the identification and analysis of putative DNA MTases in five legumes, including chickpea, soybean, pigeonpea, Medicago and Lotus. MTases in legumes could be classified in known MET, CMT, DRM and DNA nucleotide methyltransferases (DNMT2 subfamilies based on their domain organization. First three MTases represent DNA MTases, whereas DNMT2 represents a transfer RNA (tRNA MTase. Structural comparison of all the MTases in plants with known MTases in mammalian and plant systems have been reported to assign structural features in context of biological functions of these proteins. The structure analysis clearly specified regions crucial for protein-protein interactions and regions important for nucleosome binding in various domains of CMT and MET proteins. In addition, structural model of DRM suggested that circular permutation of motifs does not have any effect on overall structure of DNA methyltransferase domain. These results provide valuable insights into role of various domains in molecular recognition and should facilitate mechanistic understanding of their function in mediating specific methylation patterns. Further, the comprehensive gene expression analyses of MTases in legumes provided evidence of their role in various developmental processes throughout the plant life cycle and response to various abiotic stresses. Overall, our study will be very helpful in establishing the specific functions of DNA MTases in legumes.

  3. An integrated disease/pharmacokinetic/pharmacodynamic model suggests improved interleukin-21 regimens validated prospectively for mouse solid cancers.

    Directory of Open Access Journals (Sweden)

    Moran Elishmereni

    2011-09-01

    Full Text Available Interleukin (IL-21 is an attractive antitumor agent with potent immunomodulatory functions. Yet thus far, the cytokine has yielded only partial responses in solid cancer patients, and conditions for beneficial IL-21 immunotherapy remain elusive. The current work aims to identify clinically-relevant IL-21 regimens with enhanced efficacy, based on mathematical modeling of long-term antitumor responses. For this purpose, pharmacokinetic (PK and pharmacodynamic (PD data were acquired from a preclinical study applying systemic IL-21 therapy in murine solid cancers. We developed an integrated disease/PK/PD model for the IL-21 anticancer response, and calibrated it using selected "training" data. The accuracy of the model was verified retrospectively under diverse IL-21 treatment settings, by comparing its predictions to independent "validation" data in melanoma and renal cell carcinoma-challenged mice (R(2>0.90. Simulations of the verified model surfaced important therapeutic insights: (1 Fractionating the standard daily regimen (50 µg/dose into a twice daily schedule (25 µg/dose is advantageous, yielding a significantly lower tumor mass (45% decrease; (2 A low-dose (12 µg/day regimen exerts a response similar to that obtained under the 50 µg/day treatment, suggestive of an equally efficacious dose with potentially reduced toxicity. Subsequent experiments in melanoma-bearing mice corroborated both of these predictions with high precision (R(2>0.89, thus validating the model also prospectively in vivo. Thus, the confirmed PK/PD model rationalizes IL-21 therapy, and pinpoints improved clinically-feasible treatment schedules. Our analysis demonstrates the value of employing mathematical modeling and in silico-guided design of solid tumor immunotherapy in the clinic.

  4. Conceptual Models in Health Informatics Research: A Literature Review and Suggestions for Development.

    Science.gov (United States)

    Gray, Kathleen; Sockolow, Paulina

    2016-02-24

    Contributing to health informatics research means using conceptual models that are integrative and explain the research in terms of the two broad domains of health science and information science. However, it can be hard for novice health informatics researchers to find exemplars and guidelines in working with integrative conceptual models. The aim of this paper is to support the use of integrative conceptual models in research on information and communication technologies in the health sector, and to encourage discussion of these conceptual models in scholarly forums. A two-part method was used to summarize and structure ideas about how to work effectively with conceptual models in health informatics research that included (1) a selective review and summary of the literature of conceptual models; and (2) the construction of a step-by-step approach to developing a conceptual model. The seven-step methodology for developing conceptual models in health informatics research explained in this paper involves (1) acknowledging the limitations of health science and information science conceptual models; (2) giving a rationale for one's choice of integrative conceptual model; (3) explicating a conceptual model verbally and graphically; (4) seeking feedback about the conceptual model from stakeholders in both the health science and information science domains; (5) aligning a conceptual model with an appropriate research plan; (6) adapting a conceptual model in response to new knowledge over time; and (7) disseminating conceptual models in scholarly and scientific forums. Making explicit the conceptual model that underpins a health informatics research project can contribute to increasing the number of well-formed and strongly grounded health informatics research projects. This explication has distinct benefits for researchers in training, research teams, and researchers and practitioners in information, health, and other disciplines.

  5. Low modeled ozone production suggests underestimation of precursor emissions (especially NOx) in Europe

    OpenAIRE

    Oikonomakis, Emmanouil; Aksoyoglu, Sebnem; Ciarelli, Giancarlo; Baltensperger, Urs; Prévôt, André Stephan Henry

    2018-01-01

    High surface ozone concentrations, which usually occur when photochemical ozone production takes place, pose a great risk to human health and vegetation. Air quality models are often used by policy makers as tools for the development of ozone mitigation strategies. However, the modeled ozone production is often not or not enough evaluated in many ozone modeling studies. The focus of this work is to evaluate the modeled ozone production in Europe indirectly, with the use of t...

  6. Conceptual Models in Health Informatics Research: A Literature Review and Suggestions for Development

    Science.gov (United States)

    2016-01-01

    Background Contributing to health informatics research means using conceptual models that are integrative and explain the research in terms of the two broad domains of health science and information science. However, it can be hard for novice health informatics researchers to find exemplars and guidelines in working with integrative conceptual models. Objectives The aim of this paper is to support the use of integrative conceptual models in research on information and communication technologies in the health sector, and to encourage discussion of these conceptual models in scholarly forums. Methods A two-part method was used to summarize and structure ideas about how to work effectively with conceptual models in health informatics research that included (1) a selective review and summary of the literature of conceptual models; and (2) the construction of a step-by-step approach to developing a conceptual model. Results The seven-step methodology for developing conceptual models in health informatics research explained in this paper involves (1) acknowledging the limitations of health science and information science conceptual models; (2) giving a rationale for one’s choice of integrative conceptual model; (3) explicating a conceptual model verbally and graphically; (4) seeking feedback about the conceptual model from stakeholders in both the health science and information science domains; (5) aligning a conceptual model with an appropriate research plan; (6) adapting a conceptual model in response to new knowledge over time; and (7) disseminating conceptual models in scholarly and scientific forums. Conclusions Making explicit the conceptual model that underpins a health informatics research project can contribute to increasing the number of well-formed and strongly grounded health informatics research projects. This explication has distinct benefits for researchers in training, research teams, and researchers and practitioners in information, health, and other

  7. Models of text mining to measure improvements to doctoral courses suggested by “STELLA” phd survey respondents

    Directory of Open Access Journals (Sweden)

    Pasquale Pavone

    2014-10-01

    Full Text Available We present Text Mining models to thematically categorise and measure the suggestions of  PhD holders on improving PhD programmes in the STELLA survey (Statistiche in TEma di Laureati e LAvoro. The coded responses questionnaire, designed to evaluate the employment opportunities of students and assess their learning experience, included open-ended questions on how to improve PhD programmes. The Corpus analysed was taken from the data of Italian PhD holders between 2005 and 2009 in eight universities (Bergamo, Brescia, Milano Statale, Milano Bicocca, Pisa, Scuola Superiore Sant’Anna, Palermo and Pavia. The usual methodological approach to text analysis allowed us to categorize open-ended proposals of PhD courses improvements in 8 Italian Universities.

  8. Coordinating the Provision of Health Services in Humanitarian Crises: a Systematic Review of Suggested Models.

    Science.gov (United States)

    Lotfi, Tamara; Bou-Karroum, Lama; Darzi, Andrea; Hajjar, Rayan; El Rahyel, Ahmed; El Eid, Jamale; Itani, Mira; Brax, Hneine; Akik, Chaza; Osman, Mona; Hassan, Ghayda; El-Jardali, Fadi; Akl, Elie

    2016-08-03

    Our objective was to identify published models of coordination between entities funding or delivering health services in humanitarian crises, whether the coordination took place during or after the crises. We included reports describing models of coordination in sufficient detail to allow reproducibility. We also included reports describing implementation of identified models, as case studies. We searched Medline, PubMed, EMBASE, Cochrane Central Register of Controlled Trials, CINAHL, PsycINFO, and the WHO Global Health Library. We also searched websites of relevant organizations. We followed standard systematic review methodology. Our search captured 14,309 citations. The screening process identified 34 eligible papers describing five models of coordination of delivering health services: the "Cluster Approach" (with 16 case studies), the 4Ws "Who is Where, When, doing What" mapping tool (with four case studies), the "Sphere Project" (with two case studies), the "5x5" model (with one case study), and the "model of information coordination" (with one case study). The 4Ws and the 5x5 focus on coordination of services for mental health, the remaining models do not focus on a specific health topic. The Cluster approach appears to be the most widely used. One case study was a mixed implementation of the Cluster approach and the Sphere model. We identified no model of coordination for funding of health service. This systematic review identified five proposed coordination models that have been implemented by entities funding or delivering health service in humanitarian crises. There is a need to compare the effect of these different models on outcomes such as availability of and access to health services.

  9. Mathematical modeling suggests that periodontitis behaves as a non-linear chaotic dynamical process

    NARCIS (Netherlands)

    Papantonopoulos, G.H.; Takahashi, K.; Bountis, T.; Loos, B.G.

    2013-01-01

    Background: This study aims to expand on a previously presented cellular automata model and further explore the non-linear dynamics of periodontitis. Additionally the authors investigated whether their mathematical model could predict the two known types of periodontitis, aggressive (AgP) and

  10. Toward an Integrative Model of Creativity and Personality: Theoretical Suggestions and Preliminary Empirical Testing

    Science.gov (United States)

    Fü rst, Guillaume; Ghisletta, Paolo; Lubart, Todd

    2016-01-01

    The present work proposes an integrative model of creativity that includes personality traits and cognitive processes. This model hypothesizes that three high-order personality factors predict two main process factors, which in turn predict intensity and achievement of creative activities. The personality factors are: "Plasticity" (high…

  11. A Multi-Scale Energy Demand Model suggests sharing Market Risks with Intelligent Energy Cooperatives

    NARCIS (Netherlands)

    G. Methenitis (Georgios); M. Kaisers (Michael); J.A. La Poutré (Han)

    2015-01-01

    textabstractIn this paper, we propose a multi-scale model of energy demand that is consistent with observations at a macro scale, in our use-case standard load profiles for (residential) electric loads. We employ the model to study incentives to assume the risk of volatile market prices for

  12. The Substitution Augmentation Modification Redefinition (SAMR) Model: A Critical Review and Suggestions for Its Use

    Science.gov (United States)

    Hamilton, Erica R.; Rosenberg, Joshua M.; Akcaoglu, Mete

    2016-01-01

    The Substitution, Augmentation, Modification, and Redefinition (SAMR) model is a four-level, taxonomy-based approach for selecting, using, and evaluating technology in K-12 settings (Puentedura 2006). Despite its increasing popularity among practitioners, the SAMR model is not currently represented in the extant literature. To focus the ongoing…

  13. Deep ocean model penetrator experiments

    International Nuclear Information System (INIS)

    Freeman, T.J.; Burdett, J.R.F.

    1986-01-01

    Preliminary trials of experimental model penetrators in the deep ocean have been conducted as an international collaborative exercise by participating members (national bodies and the CEC) of the Engineering Studies Task Group of the Nuclear Energy Agency's Seabed Working Group. This report describes and gives the results of these experiments, which were conducted at two deep ocean study areas in the Atlantic: Great Meteor East and the Nares Abyssal Plain. Velocity profiles of penetrators of differing dimensions and weights have been determined as they free-fell through the water column and impacted the sediment. These velocity profiles are used to determine the final embedment depth of the penetrators and the resistance to penetration offered by the sediment. The results are compared with predictions of embedment depth derived from elementary models of a penetrator impacting with a sediment. It is tentatively concluded that once the resistance to penetration offered by a sediment at a particular site has been determined, this quantity can be used to sucessfully predict the embedment that penetrators of differing sizes and weights would achieve at the same site

  14. Mathematical analysis of a mouse experiment suggests little role for resource depletion in controlling influenza infection within host

    OpenAIRE

    Ahmed, Hasan; Moore, James; Manicassamy, Balaji; Garcia-Sastre, Adolfo; Handel, Andreas; Antia, Rustom

    2017-01-01

    How important is resource depletion (e.g. depletion of target cells) in controlling infection within a host? And how can we distinguish between resource depletion and other mechanisms that may contribute to decline of pathogen load or lead to pathogen clearance? In this paper we examine data from a previously published experiment. In this experiment, mice were infected with influenza virus carrying a green fluorescent protein reporter gene, and the proportion of lung epithelial cells that wer...

  15. Discrete Dynamical Modeling of Influenza Virus Infection Suggests Age-Dependent Differences in Immunity.

    Science.gov (United States)

    Keef, Ericka; Zhang, Li Ang; Swigon, David; Urbano, Alisa; Ermentrout, G Bard; Matuszewski, Michael; Toapanta, Franklin R; Ross, Ted M; Parker, Robert S; Clermont, Gilles

    2017-12-01

    Immunosenescence, an age-related decline in immune function, is a major contributor to morbidity and mortality in the elderly. Older hosts exhibit a delayed onset of immunity and prolonged inflammation after an infection, leading to excess damage and a greater likelihood of death. Our study applies a rule-based model to infer which components of the immune response are most changed in an aged host. Two groups of BALB/c mice (aged 12 to 16 weeks and 72 to 76 weeks) were infected with 2 inocula: a survivable dose of 50 PFU and a lethal dose of 500 PFU. Data were measured at 10 points over 19 days in the sublethal case and at 6 points over 7 days in the lethal case, after which all mice had died. Data varied primarily in the onset of immunity, particularly the inflammatory response, which led to a 2-day delay in the clearance of the virus from older hosts in the sublethal cohort. We developed a Boolean model to describe the interactions between the virus and 21 immune components, including cells, chemokines, and cytokines, of innate and adaptive immunity. The model identifies distinct sets of rules for each age group by using Boolean operators to describe the complex series of interactions that activate and deactivate immune components. Our model accurately simulates the immune responses of mice of both ages and with both inocula included in the data (95% accurate for younger mice and 94% accurate for older mice) and shows distinct rule choices for the innate immunity arm of the model between younger and aging mice in response to influenza A virus infection. IMPORTANCE Influenza virus infection causes high morbidity and mortality rates every year, especially in the elderly. The elderly tend to have a delayed onset of many immune responses as well as prolonged inflammatory responses, leading to an overall weakened response to infection. Many of the details of immune mechanisms that change with age are currently not well understood. We present a rule-based model of the

  16. A Latent Growth Model Suggests that Empathy of Medical Students Does Not Decline over Time

    Science.gov (United States)

    Costa, Patrício; Magalhães, Eunice; Costa, Manuel João

    2013-01-01

    Empathy is a relevant attribute in the context of patient care. However, a decline in empathy throughout medical education has been reported in North-American medical schools, particularly, in the transition to clinical training. The present study aims to longitudinally model empathy during medical school at three time points: at the entrance,…

  17. Modelling soil organic carbon in Danish agricultural soils suggests low potential for future carbon sequestration

    DEFF Research Database (Denmark)

    Taghizadeh-Toosi, Arezoo; Olesen, Jørgen Eivind

    2016-01-01

    Soil organic carbon (SOC) is in active exchange with the atmosphere. The amount of organic carbon (OC) input into the soil and SOC turnover rate are important for predicting the carbon (C) sequestration potential of soils subject to changes in land-use and climate. The C-TOOL model was developed...

  18. DNA databanks and consent: a suggested policy option involving an authorization model.

    Science.gov (United States)

    Caulfield, Timothy; Upshur, Ross E G; Daar, Abdallah

    2003-01-03

    Genetic databases are becoming increasingly common as a means of determining the relationship between lifestyle, environmental exposures and genetic diseases. These databases rely on large numbers of research subjects contributing their genetic material to successfully explore the genetic basis of disease. However, as all possible research questions that can be posed of the data are unknown, an unresolved ethical issue is the status of informed consent for future research uses of genetic material. In this paper, we discuss the difficulties of an informed consent model for future ineffable uses of genetic data. We argue that variations on consent, such as presumed consent, blanket consent or constructed consent fail to meet the standards required by current informed consent doctrine and are distortions of the original concept. In this paper, we propose the concept of an authorization model whereby participants in genetic data banks are able to exercise a certain amount of control over future uses of genetic data. We argue this preserves the autonomy of individuals at the same time as allowing them to give permission and discretion to researchers for certain types of research. The authorization model represents a step forward in the debate about informed consent in genetic databases. The move towards an authorization model would require changes in the regulatory and legislative environments. Additionally, empirical support of the utility and acceptability of authorization is required.

  19. DNA databanks and consent: A suggested policy option involving an authorization model

    Directory of Open Access Journals (Sweden)

    Daar Abdallah

    2003-01-01

    Full Text Available Abstract Background Genetic databases are becoming increasingly common as a means of determining the relationship between lifestyle, environmental exposures and genetic diseases. These databases rely on large numbers of research subjects contributing their genetic material to successfully explore the genetic basis of disease. However, as all possible research questions that can be posed of the data are unknown, an unresolved ethical issue is the status of informed consent for future research uses of genetic material. Discussion In this paper, we discuss the difficulties of an informed consent model for future ineffable uses of genetic data. We argue that variations on consent, such as presumed consent, blanket consent or constructed consent fail to meet the standards required by current informed consent doctrine and are distortions of the original concept. In this paper, we propose the concept of an authorization model whereby participants in genetic data banks are able to exercise a certain amount of control over future uses of genetic data. We argue this preserves the autonomy of individuals at the same time as allowing them to give permission and discretion to researchers for certain types of research. Summary The authorization model represents a step forward in the debate about informed consent in genetic databases. The move towards an authorization model would require changes in the regulatory and legislative environments. Additionally, empirical support of the utility and acceptability of authorization is required.

  20. Experiments beyond the standard model

    International Nuclear Information System (INIS)

    Perl, M.L.

    1984-09-01

    This paper is based upon lectures in which I have described and explored the ways in which experimenters can try to find answers, or at least clues toward answers, to some of the fundamental questions of elementary particle physics. All of these experimental techniques and directions have been discussed fully in other papers, for example: searches for heavy charged leptons, tests of quantum chromodynamics, searches for Higgs particles, searches for particles predicted by supersymmetric theories, searches for particles predicted by technicolor theories, searches for proton decay, searches for neutrino oscillations, monopole searches, studies of low transfer momentum hadron physics at very high energies, and elementary particle studies using cosmic rays. Each of these subjects requires several lectures by itself to do justice to the large amount of experimental work and theoretical thought which has been devoted to these subjects. My approach in these tutorial lectures is to describe general ways to experiment beyond the standard model. I will use some of the topics listed to illustrate these general ways. Also, in these lectures I present some dreams and challenges about new techniques in experimental particle physics and accelerator technology, I call these Experimental Needs. 92 references

  1. A suggested model for physical examination and conservative treatment of athletic pubalgia.

    Science.gov (United States)

    Hegedus, Eric J; Stern, Ben; Reiman, Michael P; Tarara, Dan; Wright, Alexis A

    2013-02-01

    Athletic pubalgia (AP) is a chronic debilitating syndrome that affects many athletes. As a syndrome, AP is difficult to diagnose both with clinical examination and imaging. AP is also a challenge for conservative intervention with randomized controlled trials showing mixed success rates. In other syndromes where clinical diagnosis and conservative treatment have been less than clear, a paradigm has been suggested as a framework for clinical decision making. To propose a new clinical diagnostic and treatment paradigm for the conservative management of AP. Relevant studies were viewed with regard to diagnosis and intervention and where a gap in evidence existed, clinical expertise was used to fill that gap and duly noted. A new paradigm is proposed to assist with clinical diagnosis and non-surgical intervention in patients suffering with AP. The level of evidence supporting this paradigm, according to the SORT taxonomy, is primarily level 2B. Further testing is warranted but following the suggested paradigm should lead to a clearer diagnosis of AP and allow more meaningful research into homogeneous patient populations within the AP diagnostic cluster. Strength-of-Recommendation Taxonomy (SORT): 2B. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Introducing radiology report checklists among residents: adherence rates when suggesting versus requiring their use and early experience in improving accuracy.

    Science.gov (United States)

    Powell, Daniel K; Lin, Eaton; Silberzweig, James E; Kagetsu, Nolan J

    2014-03-01

    To retrospectively compare resident adherence to checklist-style structured reporting for maxillofacial computed tomography (CT) from the emergency department (when required vs. suggested between two programs). To compare radiology resident reporting accuracy before and after introduction of the structured report and assess its ability to decrease the rate of undetected pathology. We introduced a reporting checklist for maxillofacial CT into our dictation software without specific training, requiring it at one program and suggesting it at another. We quantified usage among residents and compared reporting accuracy, before and after counting and categorizing faculty addenda. There was no significant change in resident accuracy in the first few months, with residents acting as their own controls (directly comparing performance with and without the checklist). Adherence to the checklist at program A (where it originated and was required) was 85% of reports compared to 9% of reports at program B (where it was suggested). When using program B as a secondary control, there was no significant difference in resident accuracy with or without using the checklist (comparing different residents using the checklist to those not using the checklist). Our results suggest that there is no automatic value of checklists for improving radiology resident reporting accuracy. They also suggest the importance of focused training, checklist flexibility, and a period of adjustment to a new reporting style. Mandatory checklists were readily adopted by residents but not when simply suggested. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

  3. Active tension network model suggests an exotic mechanical state realized in epithelial tissues

    Science.gov (United States)

    Noll, Nicholas; Mani, Madhav; Heemskerk, Idse; Streichan, Sebastian J.; Shraiman, Boris I.

    2017-12-01

    Mechanical interactions play a crucial role in epithelial morphogenesis, yet understanding the complex mechanisms through which stress and deformation affect cell behaviour remains an open problem. Here we formulate and analyse the active tension network (ATN) model, which assumes that the mechanical balance of cells within a tissue is dominated by cortical tension and introduces tension-dependent active remodelling of the cortex. We find that ATNs exhibit unusual mechanical properties. Specifically, an ATN behaves as a fluid at short times, but at long times supports external tension like a solid. Furthermore, an ATN has an extensively degenerate equilibrium mechanical state associated with a discrete conformal--`isogonal'--deformation of cells. The ATN model predicts a constraint on equilibrium cell geometries, which we demonstrate to approximately hold in certain epithelial tissues. We further show that isogonal modes are observed in the fruit fly embryo, accounting for the striking variability of apical areas of ventral cells and helping understand the early phase of gastrulation. Living matter realizes new and exotic mechanical states, the study of which helps to understand biological phenomena.

  4. Hypothalamus transcriptome profile suggests an anorexia-cachexia syndrome in the anx/anx mouse model.

    Science.gov (United States)

    Mercader, Josep Maria; Lozano, Juan José; Sumoy, Lauro; Dierssen, Mara; Visa, Joana; Gratacòs, Mònica; Estivill, Xavier

    2008-11-12

    The anx/anx mouse displays poor appetite and lean appearance and is considered a good model for the study of anorexia nervosa. To identify new genes involved in feeding behavior and body weight regulation we performed an expression profiling in the hypothalamus of the anx/anx mice. Using commercial microarrays we detected 156 differentially expressed genes and validated 92 of those using TaqMan low-density arrays. The expression of a set of 87 candidate genes selected based on literature evidences was also quantified by TaqMan low-density arrays. Our results showed enrichment in deregulated genes involved in cell death, cell morphology, and cancer, as well as an alteration of several signaling circuits involved in energy balance including neuropeptide Y and melanocortin signaling. The expression profile along with the phenotype led us to conclude that anx/anx mice resemble the anorexia-cachexia syndrome typically observed in cancer, infection with human immunodeficiency virus or chronic diseases, rather than starvation, and that anx/anx mice could be considered a good model for the treatment and investigation of this condition.

  5. Research Spotlight: Model suggests path to ending the ongoing Haitian cholera epidemic

    Science.gov (United States)

    Schultz, Colin

    2011-05-01

    Since early November 2010 a deadly cholera epidemic has been spreading across the Caribbean nation of Haiti, killing thousands of people and infecting hundreds of thousands. While infection rates are being actively monitored, health organizations have been left without a clear understanding of exactly how the disease has spread across Haiti. Cholera can spread through exposure to contaminated water, and the disease travels over long distances if an infected individual moves around the country. Using representations of these two predominant dispersion mechanisms, along with information on the size of the susceptible population, the number of infected individuals, and the aquatic concentration of the cholera-causing bacteria for more than 500 communities, Bertuzzo et al. designed a model that was able to accurately reproduce the progression of the Haitian cholera epidemic. (Geophysical Research Letters, doi:10.1029/2011GL046823, 2011)

  6. A global experiment suggests climate warming will not accelerate litter decomposition in streams but might reduce carbon sequestration

    OpenAIRE

    Boyero, Luz; Pearson, R.G.; Gessner, M.O.; Barmuta, L.A.; Ferreira, V.; Graça, M.A.S.; Dudgeon, D.; Boulton, A.J.; Callisto, M.; Chauvet, E.

    2011-01-01

    The decomposition of plant litter is one of the most important ecosystem processes in the biosphere and is particularly sensitive to climate warming. Aquatic ecosystems are well suited to studying warming effects on decomposition because the otherwise confounding influence of moisture is constant. By using a latitudinal temperature gradient in an unprecedented global experiment in streams, we found that climate warming will likely hasten microbial litter decomposition and produce an equivalen...

  7. Coumarins as Potential Antioxidant Agents Complemented with Suggested Mechanisms and Approved by Molecular Modeling Studies

    Directory of Open Access Journals (Sweden)

    Yasameen K. Al-Majedy

    2016-01-01

    Full Text Available Syntheses of coumarins, which are a structurally interesting antioxidant activity, was done in this article. The modification of 7-hydroxycoumarin by different reaction steps was done to yield target compounds. Molecular structures were characterized by different spectroscopical techniques (Fourier transformation infrared and nuclear magnetic resonance. Antioxidant activities were performed by using various in vitro spectrophometric assays against 1,1-diphenyl-2-picrylhydrazyl (DPPH radical and hydrogen peroxide (H2O2. All compounds exhibited high efficiency as antioxidants compared to ascorbic acid. The highest efficiency scavenging activity was found for compound 3 (91.0 ± 5.0, followed by compounds 2 and 4 (88.0 ± 2.00; and 87.0 ± 3.00. Ascorbic acid C was used as a standard drug with a percentage inhibition of 91.00 ± 1.5. The mechanism of the synthesized compounds as antioxidants was also studied. Hartree–Fock–based quantum chemical studies have been carried out with the basis set to 3-21G, in order to obtain information about the three-dimensional (3D geometries, electronic structure, molecular modeling, and electronic levels, namely HOMO (highest occupied molecular orbital and LUMO (lowest unoccupied molecular orbital, to understand the antioxidant activity for the synthesized compounds.

  8. Modeling the Experience of Emotion

    OpenAIRE

    Broekens, Joost

    2009-01-01

    Affective computing has proven to be a viable field of research comprised of a large number of multidisciplinary researchers resulting in work that is widely published. The majority of this work consists of computational models of emotion recognition, computational modeling of causal factors of emotion and emotion expression through rendered and robotic faces. A smaller part is concerned with modeling the effects of emotion, formal modeling of cognitive appraisal theory and models of emergent...

  9. University of Glasgow at TREC 2014: Experiments with Terrier in Contextual Suggestion, Temporal Summarisation and Web Tracks

    Science.gov (United States)

    2014-11-01

    automatic selec- Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1...this year on the generation of more meaningful and interesting descriptions for each venue sug- gestion , instead of simply returning the LBSN’s... gestions track. Figures in bold represent the top performances. follows. For each venue suggestion, we extracted the reviews that have been entered by

  10. Diagnosis of arterial gas embolism in SCUBA diving: modification suggestion of autopsy techniques and experience in eight cases.

    Science.gov (United States)

    Casadesús, Josep M; Aguirre, Fernando; Carrera, Ana; Boadas-Vaello, Pere; Serrando, Maria T; Reina, Francisco

    2018-03-01

    The purpose of this study was to suggest modifications of autopsy techniques in order to improve post-mortem diagnosis of arterial gas embolism (AGE) based on multidisciplinary investigation of SCUBA diving fatalities. Five adult human cadavers from the voluntary donation program of the Human Anatomy Laboratory, and eight judicial autopsied bodies of SCUBA divers from the Forensic Pathology Service were assessed. Before performing any autopsies, we accessed the diving plan and the divers' profiles for each case. We then introduced a new dissection procedure that included identification, isolation, and manipulation of carotid, vertebral and thoracic arterial systems. The dissected vascular structures that allowed optimall isolation of the systemic arterial circulation were identified and ligated. In three of the eight judicial cases, we had a strongly suggestive history of arterial gas embolism following pulmonary barotrauma (PBt/AGE). In these cases, the additional arterial dissection allowed us to clearly diagnose AGE in one of them. The autopsy of the rest of the cases showed other causes of death such as asphyxia by drowning and heart attack. In all cases we were able to reject decompression sickness, and in some of them we showed the presence of artefacts secondary to decomposition and resuscitation maneuvers. These results allow us to suggest a specific autopsy technique divided into four steps, aimed at confirming or excluding some evidence of dysbaric disorders according to a re-enactment of the incident. We have demonstrated the presence of large volumes of intravascular air, which is typical of PBt/AGE.

  11. Numerical experiments modelling turbulent flows

    Science.gov (United States)

    Trefilík, Jiří; Kozel, Karel; Příhoda, Jaromír

    2014-03-01

    The work aims at investigation of the possibilities of modelling transonic flows mainly in external aerodynamics. New results are presented and compared with reference data and previously achieved results. For the turbulent flow simulations two modifications of the basic k - ω model are employed: SST and TNT. The numerical solution was achieved by using the MacCormack scheme on structured non-ortogonal grids. Artificial dissipation was added to improve the numerical stability.

  12. Numerical experiments modelling turbulent flows

    Directory of Open Access Journals (Sweden)

    Trefilík Jiří

    2014-03-01

    Full Text Available The work aims at investigation of the possibilities of modelling transonic flows mainly in external aerodynamics. New results are presented and compared with reference data and previously achieved results. For the turbulent flow simulations two modifications of the basic k – ω model are employed: SST and TNT. The numerical solution was achieved by using the MacCormack scheme on structured non-ortogonal grids. Artificial dissipation was added to improve the numerical stability.

  13. Experience economy meets business model design

    DEFF Research Database (Denmark)

    Gudiksen, Sune Klok; Smed, Søren Graakjær; Poulsen, Søren Bolvig

    2012-01-01

    companies automatically get a higher prize when offering an experience setting to the customer illustrated by the coffee example. Organizations that offer experiences still have an advantage but when an increasing number of organizations enter the experience economy the competition naturally gets tougher......Through the last decade the experience economy has found solid ground and manifested itself as a parameter where business and organizations can differentiate from competitors. The fundamental premise is the one found in Pine & Gilmores model from 1999 over 'the progression of economic value' where...... produced, designed or staged experience that gains the most profit or creates return of investment. It becomes more obvious that other parameters in the future can be a vital part of the experience economy and one of these is business model innovation. Business model innovation is about continuous...

  14. Immunization experiments using the rodent caries model.

    Science.gov (United States)

    Smith, D J; Taubman, M A

    1976-04-01

    Taken together, the immunization experiments which have been performed in the rat caries model system appear to suggest a correlation between the presence of salivary antibody to S mutans and reductions in caries caused by these bacteria. However, the multifactorial nature of this disease does not permit at present the conclusion that the presence of this antibody is both necessary and sufficient to give rise to the demonstrated effects on pathogenesis. To clarify the role of salivary antibody, several refinements may be required in the current model. Immunization procedures that elicit only a local antibody response would both simplify interpretations of effects and would be more desirable for use as a vaccine. Such procedures might include intraductal installation of antigen in the parotid gland which has been demonstrated to result in this type of response. An additional refinement stems from the knowledge that the kinds of immunization procedures currently used stimulated both cellular immune and soluble antibody systems, potentially giving rise to a rather broad spectrum of immune responses. Therefore, it might be useful to study the effects on S mutans pathogenesis in rats in which certain of these responses have been repressed, for example, by thymectomy, antilymphocyte serum, and so on. Also, each of these approaches would be measurably enhanced by more sensitive techniques to monitor immunological events in the oral cavity. Refinements in the selection and use of relevant antigens of S mutans also are necessary to delineate the in vivo mechanism of immunological interference in the pathogenesis of cariogenic streptococci. Approaches involve the use of purified GTF antigens or cell surface antigens both in the investigation of these mechanisms in in vitro models using antibody specifically directed to these antigens and in rat immunization experiments using immunogenic preparations of these materials. In addition, alterations in the diet and challenge

  15. Atmospheric statistical dynamic models. Climate experiments: albedo experiments with a zonal atmospheric model

    International Nuclear Information System (INIS)

    Potter, G.L.; Ellsaesser, H.W.; MacCracken, M.C.; Luther, F.M.

    1978-06-01

    The zonal model experiments with modified surface boundary conditions suggest an initial chain of feedback processes that is largest at the site of the perturbation: deforestation and/or desertification → increased surface albedo → reduced surface absorption of solar radiation → surface cooling and reduced evaporation → reduced convective activity → reduced precipitation and latent heat release → cooling of upper troposphere and increased tropospheric lapse rates → general global cooling and reduced precipitation. As indicated above, although the two experiments give similar overall global results, the location of the perturbation plays an important role in determining the response of the global circulation. These two-dimensional model results are also consistent with three-dimensional model experiments. These results have tempted us to consider the possibility that self-induced growth of the subtropical deserts could serve as a possible mechanism to cause the initial global cooling that then initiates a glacial advance thus activating the positive feedback loop involving ice-albedo feedback (also self-perpetuating). Reversal of the cycle sets in when the advancing ice cover forces the wave-cyclone tracks far enough equatorward to quench (revegetate) the subtropical deserts

  16. Modeling a High Explosive Cylinder Experiment

    Science.gov (United States)

    Zocher, Marvin A.

    2017-06-01

    Cylindrical assemblies constructed from high explosives encased in an inert confining material are often used in experiments aimed at calibrating and validating continuum level models for the so-called equation of state (constitutive model for the spherical part of the Cauchy tensor). Such is the case in the work to be discussed here. In particular, work will be described involving the modeling of a series of experiments involving PBX-9501 encased in a copper cylinder. The objective of the work is to test and perhaps refine a set of phenomenological parameters for the Wescott-Stewart-Davis reactive burn model. The focus of this talk will be on modeling the experiments, which turned out to be non-trivial. The modeling is conducted using ALE methodology.

  17. Firn Model Intercomparison Experiment (FirnMICE)

    DEFF Research Database (Denmark)

    Lundin, Jessica M.D.; Stevens, C. Max; Arthern, Robert

    2017-01-01

    Evolution of cold dry snow and firn plays important roles in glaciology; however, the physical formulation of a densification law is still an active research topic. We forced eight firn-densification models and one seasonal-snow model in six different experiments by imposing step changes in tempe......Evolution of cold dry snow and firn plays important roles in glaciology; however, the physical formulation of a densification law is still an active research topic. We forced eight firn-densification models and one seasonal-snow model in six different experiments by imposing step changes...

  18. ‘Cape capture’: Geologic data and modeling results suggest the Holocene loss of a Carolina Cape

    Science.gov (United States)

    Thieler, E. Robert; Ashton, Andrew D.

    2011-01-01

    For more than a century, the origin and evolution of the set of cuspate forelands known as the Carolina Capes—Hatteras, Lookout, Fear, and Romain—off the eastern coast of the United States have been discussed and debated. The consensus conceptual model is not only that these capes existed through much or all of the Holocene transgression, but also that their number has not changed. Here we describe bathymetric, lithologic, seismic, and chronologic data that suggest another cape may have existed between Capes Hatteras and Lookout during the early to middle Holocene. This cape likely formed at the distal end of the Neuse-Tar-Pamlico fluvial system during the early Holocene transgression, when this portion of the shelf was flooded ca. 9 cal (calibrated) kyr B.P., and was probably abandoned by ca. 4 cal kyr B.P., when the shoreline attained its present general configuration. Previously proposed mechanisms for cape formation suggest that the large-scale, rhythmic pattern of the Carolina Capes arose from a hydrodynamic template or the preexisting geologic framework. Numerical modeling, however, suggests that the number and spacing of capes can be dynamic, and that a coast can self-organize in response to a high-angle-wave instability in shoreline shape. In shoreline evolution model simulations, smaller cuspate forelands are subsumed by larger neighbors over millennial time scales through a process of ‘cape capture.’ The suggested former cape in Raleigh Bay represents the first interpreted geological evidence of dynamic abandonment suggested by the self-organization hypothesis. Cape capture may be a widespread process in coastal environments with large-scale rhythmic shoreline features; its preservation in the sedimentary record will vary according to geologic setting, physical processes, and sea-level history.

  19. Modeling of laser-driven hydrodynamics experiments

    Science.gov (United States)

    di Stefano, Carlos; Doss, Forrest; Rasmus, Alex; Flippo, Kirk; Desjardins, Tiffany; Merritt, Elizabeth; Kline, John; Hager, Jon; Bradley, Paul

    2017-10-01

    Correct interpretation of hydrodynamics experiments driven by a laser-produced shock depends strongly on an understanding of the time-dependent effect of the irradiation conditions on the flow. In this talk, we discuss the modeling of such experiments using the RAGE radiation-hydrodynamics code. The focus is an instability experiment consisting of a period of relatively-steady shock conditions in which the Richtmyer-Meshkov process dominates, followed by a period of decaying flow conditions, in which the dominant growth process changes to Rayleigh-Taylor instability. The use of a laser model is essential for capturing the transition. also University of Michigan.

  20. A multi-scale distribution model for non-equilibrium populations suggests resource limitation in an endangered rodent.

    Directory of Open Access Journals (Sweden)

    William T Bean

    Full Text Available Species distributions are known to be limited by biotic and abiotic factors at multiple temporal and spatial scales. Species distribution models, however, frequently assume a population at equilibrium in both time and space. Studies of habitat selection have repeatedly shown the difficulty of estimating resource selection if the scale or extent of analysis is incorrect. Here, we present a multi-step approach to estimate the realized and potential distribution of the endangered giant kangaroo rat. First, we estimate the potential distribution by modeling suitability at a range-wide scale using static bioclimatic variables. We then examine annual changes in extent at a population-level. We define "available" habitat based on the total suitable potential distribution at the range-wide scale. Then, within the available habitat, model changes in population extent driven by multiple measures of resource availability. By modeling distributions for a population with robust estimates of population extent through time, and ecologically relevant predictor variables, we improved the predictive ability of SDMs, as well as revealed an unanticipated relationship between population extent and precipitation at multiple scales. At a range-wide scale, the best model indicated the giant kangaroo rat was limited to areas that received little to no precipitation in the summer months. In contrast, the best model for shorter time scales showed a positive relation with resource abundance, driven by precipitation, in the current and previous year. These results suggest that the distribution of the giant kangaroo rat was limited to the wettest parts of the drier areas within the study region. This multi-step approach reinforces the differing relationship species may have with environmental variables at different scales, provides a novel method for defining "available" habitat in habitat selection studies, and suggests a way to create distribution models at spatial and

  1. Measurement Error in Designed Experiments for Second Order Models

    OpenAIRE

    McMahan, Angela Renee

    1997-01-01

    Measurement error (ME) in the factor levels of designed experiments is often overlooked in the planning and analysis of experimental designs. A familiar model for this type of ME, called the Berkson error model, is discussed at length. Previous research has examined the effect of Berkson error on two-level factorial and fractional factorial designs. This dissertation extends the examination to designs for second order models. The results are used to suggest ...

  2. Argonne Bubble Experiment Thermal Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Buechler, Cynthia Eileen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-12-03

    This report will describe the Computational Fluid Dynamics (CFD) model that was developed to calculate the temperatures and gas volume fractions in the solution vessel during the irradiation. It is based on the model used to calculate temperatures and volume fractions in an annular vessel containing an aqueous solution of uranium . The experiment was repeated at several electron beam power levels, but the CFD analysis was performed only for the 12 kW irradiation, because this experiment came the closest to reaching a steady-state condition. The aim of the study is to compare results of the calculation with experimental measurements to determine the validity of the CFD model.

  3. Intraspecific niche models for ponderosa pine (Pinus ponderosa) suggest potential variability in population-level response to climate change

    Science.gov (United States)

    Maguire, Kaitlin C.; Shinneman, Douglas; Potter, Kevin M.; Hipkins, Valerie D.

    2018-01-01

    Unique responses to climate change can occur across intraspecific levels, resulting in individualistic adaptation or movement patterns among populations within a given species. Thus, the need to model potential responses among genetically distinct populations within a species is increasingly recognized. However, predictive models of future distributions are regularly fit at the species level, often because intraspecific variation is unknown or is identified only within limited sample locations. In this study, we considered the role of intraspecific variation to shape the geographic distribution of ponderosa pine (Pinus ponderosa), an ecologically and economically important tree species in North America. Morphological and genetic variation across the distribution of ponderosa pine suggest the need to model intraspecific populations: the two varieties (var. ponderosa and var. scopulorum) and several haplotype groups within each variety have been shown to occupy unique climatic niches, suggesting populations have distinct evolutionary lineages adapted to different environmental conditions. We utilized a recently-available, geographically-widespread dataset of intraspecific variation (haplotypes) for ponderosa pine and a recently-devised lineage distance modeling approach to derive additional, likely intraspecific occurrence locations. We confirmed the relative uniqueness of each haplotype-climate relationship using a niche-overlap analysis, and developed ecological niche models (ENMs) to project the distribution for two varieties and eight haplotypes under future climate forecasts. Future projections of haplotype niche distributions generally revealed greater potential range loss than predicted for the varieties. This difference may reflect intraspecific responses of distinct evolutionary lineages. However, directional trends are generally consistent across intraspecific levels, and include a loss of distributional area and an upward shift in elevation. Our results

  4. CFD and FEM modeling of PPOOLEX experiments

    Energy Technology Data Exchange (ETDEWEB)

    Paettikangas, T.; Niemi, J.; Timperi, A. (VTT Technical Research Centre of Finland (Finland))

    2011-01-15

    Large-break LOCA experiment performed with the PPOOLEX experimental facility is analysed with CFD calculations. Simulation of the first 100 seconds of the experiment is performed by using the Euler-Euler two-phase model of FLUENT 6.3. In wall condensation, the condensing water forms a film layer on the wall surface, which is modelled by mass transfer from the gas phase to the liquid water phase in the near-wall grid cell. The direct-contact condensation in the wetwell is modelled with simple correlations. The wall condensation and direct-contact condensation models are implemented with user-defined functions in FLUENT. Fluid-Structure Interaction (FSI) calculations of the PPOOLEX experiments and of a realistic BWR containment are also presented. Two-way coupled FSI calculations of the experiments have been numerically unstable with explicit coupling. A linear perturbation method is therefore used for preventing the numerical instability. The method is first validated against numerical data and against the PPOOLEX experiments. Preliminary FSI calculations are then performed for a realistic BWR containment by modeling a sector of the containment and one blowdown pipe. For the BWR containment, one- and two-way coupled calculations as well as calculations with LPM are carried out. (Author)

  5. A Grammar-based Approach for Modeling User Interactions and Generating Suggestions During the Data Exploration Process.

    Science.gov (United States)

    Dabek, Filip; Caban, Jesus J

    2017-01-01

    Despite the recent popularity of visual analytics focusing on big data, little is known about how to support users that use visualization techniques to explore multi-dimensional datasets and accomplish specific tasks. Our lack of models that can assist end-users during the data exploration process has made it challenging to learn from the user's interactive and analytical process. The ability to model how a user interacts with a specific visualization technique and what difficulties they face are paramount in supporting individuals with discovering new patterns within their complex datasets. This paper introduces the notion of visualization systems understanding and modeling user interactions with the intent of guiding a user through a task thereby enhancing visual data exploration. The challenges faced and the necessary future steps to take are discussed; and to provide a working example, a grammar-based model is presented that can learn from user interactions, determine the common patterns among a number of subjects using a K-Reversible algorithm, build a set of rules, and apply those rules in the form of suggestions to new users with the goal of guiding them along their visual analytic process. A formal evaluation study with 300 subjects was performed showing that our grammar-based model is effective at capturing the interactive process followed by users and that further research in this area has the potential to positively impact how users interact with a visualization system.

  6. Model suggests potential for Porites coral population recovery after removal of anthropogenic disturbance (Luhuitou, Hainan, South China Sea)

    Science.gov (United States)

    Zhao, Meixia; Riegl, Bernhard; Yu, Kefu; Shi, Qi; Zhang, Qiaomin; Liu, Guohui; Yang, Hongqiang; Yan, Hongqiang

    2016-09-01

    Population models are important for resource management and can inform about potential trajectories useful for planning purposes, even with incomplete monitoring data. From size frequency data on Luhuitou fringing reef, Hainan, South China Sea, a matrix population model of massive corals (Porites lutea) was developed and trajectories over 100 years under no disturbance and random disturbances were projected. The model reflects a largely open population of Porites lutea, with low local recruitment and preponderance of imported recruitment. Under no further disturbance, the population of Porites lutea will grow and its size structure will change from predominance of small size classes to large size classes. Therewith, total Porites cover will increase. Even under random disturbances every 10 to 20 years, the Porites population could remain viable, albeit at lower space cover. The models suggest recovery at Luhuitou following the removal of chronic anthropogenic disturbance. Extending the area of coral reef reserves to protect the open coral community and the path of connectivity is advisable and imperative for the conservation of Hainan’s coral reefs.

  7. Modelling Virus and Antibody Dynamics during Dengue Virus Infection Suggests a Role for Antibody in Virus Clearance.

    Directory of Open Access Journals (Sweden)

    Hannah E Clapham

    2016-05-01

    Full Text Available Dengue is an infection of increasing global importance, yet uncertainty remains regarding critical aspects of its virology, immunology and epidemiology. One unanswered question is how infection is controlled and cleared during a dengue infection. Antibody is thought to play a role, but little past work has examined the kinetics of both virus and antibody during natural infections. We present data on multiple virus and antibody titres measurements recorded sequentially during infection from 53 Vietnamese dengue patients. We fit mechanistic mathematical models of the dynamics of viral replication and the host immune response to these data. These models fit the data well. The model with antibody removing virus fits the data best, but with a role suggested for ADCC or other infected cell clearance mechanisms. Our analysis therefore shows that the observed viral and antibody kinetics are consistent with antibody playing a key role in controlling viral replication. This work gives quantitative insight into the relationship between antibody levels and the efficiency of viral clearance. It will inform the future development of mechanistic models of how vaccines and antivirals might modify the course of natural dengue infection.

  8. High-resolution mutational profiling suggests the genetic validity of glioblastoma patient-derived pre-clinical models.

    Directory of Open Access Journals (Sweden)

    Shawn E Yost

    Full Text Available Recent advances in the ability to efficiently characterize tumor genomes is enabling targeted drug development, which requires rigorous biomarker-based patient selection to increase effectiveness. Consequently, representative DNA biomarkers become equally important in pre-clinical studies. However, it is still unclear how well these markers are maintained between the primary tumor and the patient-derived tumor models. Here, we report the comprehensive identification of somatic coding mutations and copy number aberrations in four glioblastoma (GBM primary tumors and their matched pre-clinical models: serum-free neurospheres, adherent cell cultures, and mouse xenografts. We developed innovative methods to improve the data quality and allow a strict comparison of matched tumor samples. Our analysis identifies known GBM mutations altering PTEN and TP53 genes, and new actionable mutations such as the loss of PIK3R1, and reveals clear patient-to-patient differences. In contrast, for each patient, we do not observe any significant remodeling of the mutational profile between primary to model tumors and the few discrepancies can be attributed to stochastic errors or differences in sample purity. Similarly, we observe ∼96% primary-to-model concordance in copy number calls in the high-cellularity samples. In contrast to previous reports based on gene expression profiles, we do not observe significant differences at the DNA level between in vitro compared to in vivo models. This study suggests, at a remarkable resolution, the genome-wide conservation of a patient's tumor genetics in various pre-clinical models, and therefore supports their use for the development and testing of personalized targeted therapies.

  9. Organizational suggestion system in the era of holding by developing an innovative model : the case of bonyade ta avon holding in Iran(an applied model

    Directory of Open Access Journals (Sweden)

    Meysam Ghasemi

    2010-01-01

    Full Text Available One of the popular ways of taking advantage of personnel creativity is through suggestionsystems. Our main question is how to implement suggestion system in holding with conglomeratestructure. The paper presents an innovative model that were named ITFSK Model with accordanceof Bonayade Taavone (a holding that has many companies and institutions with conglomeratestructure. ITFSK is a model that explains how participation management and suggestion system isimplemented effectively in huge Enterprises (holding and this approach brings continuousimprovement (kaizen and it impacts the productivity of these enterprises.The paper is based on field research and the research in Bonyade Tavan that has 22 companies and2 institutions that activity fields of the subholdings is very varied.Our model consists of five main parts such as ideas bank, think-tank, feedback, sharing ofknowledge and kaizen that was named ITFSK.Implementation of “Suggestion system” rules has immediate and significant effects on theproductivity of activities in the jobs, thus influencing the performance of processes in the analyzedorganization. Suggestion system can result in kaizen and innovation in environment oforganization.The model was used to implement and evaluate a suggestion system of holding with conglomeratedstructure. The application of the model to evaluate the suggestion system provided some goodinsights and highlighted some areas of improvement.

  10. Numerical modeling of shock-sensitivity experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, A.L.; Forest, C.A.; Kershner, J.D.; Mader, C.L.; Pimbley, G.H.

    1981-01-01

    The Forest Fire rate model of shock initiation of heterogeneous explosives has been used to study several experiments commonly performed to measure the sensitivity of explosives to shock and to study initiation by explosive-formed jets. The minimum priming charge test, the gap test, the shotgun test, sympathetic detonation, and jet initiation have been modeled numerically using the Forest Fire rate in the reactive hydrodynamic codes SIN and 2DE.

  11. Bicycle Rider Control: Observations, Modeling & Experiments

    OpenAIRE

    Kooijman, J.D.G.

    2012-01-01

    Bicycle designers traditionally develop bicycles based on experience and trial and error. Adopting modern engineering tools to model bicycle and rider dynamics and control is another method for developing bicycles. This method has the potential to evaluate the complete design space, and thereby develop well handling bicycles for specific user groups in a much shorter time span. The recent benchmarking of the Whipple bicycle model for the balance and steer of a bicycle is an opening enabling t...

  12. Modelling of isotope exchange experiments in JET

    International Nuclear Information System (INIS)

    Ehrenberg, J.

    1987-01-01

    Isotope exchange experiments from hydrogen to deuterium in JET are theoretically described by employing a simple global isotope exchange model. Experimental results for discharges with limiter temperature around 250 0 C can be approximated by this model if an additional slow diffusion process of hydrogen in the limiter bulk is assumed. In discharges where thermal desorption occurs due to higher limiter temperatures (> or approx. 1000 0 C) (post carbonisation discharges) the change over process seems to be predominantly governed by thermal processes. (orig.)

  13. The mathematical model for total pubertal growth in idiopathic growth hormone (GH) deficiency suggests a moderate role of GH dose.

    Science.gov (United States)

    Ranke, Michael B; Lindberg, Anders; Martin, David D; Bakker, Bert; Wilton, Patrick; Albertsson-Wikland, Kerstin; Cowell, Chris T; Price, David A; Reiter, Edward O

    2003-10-01

    The role of GH treatment during total pubertal growth (TPG) is still unclear. We developed a prediction model for TPG (centimeters) through a multiple regression analysis of various prepubertal parameters in 303 adolescents with idiopathic GH deficiency from the KIGS database. Prepubertal catch-up growth and near-adult height were achieved, and GH dose was kept constant at approximately 30 micro g/kg.d. The model was validated on a cohort of 36 patients from one center. Four TPG predictors explained 70% of the variability with an error SD of 4.2 cm: gender (TPG in males was >11.3 cm vs. that in females), age at onset of puberty (negative), height SD score minus midparental height SD score at puberty onset (negative), and mean GH dose during puberty (positive). Our analysis suggests that TPG in idiopathic GH deficiency is only moderately dependent on GH dose. The use of a higher GH dosage at the onset of puberty should thus depend on the individual's height development. The TPG model aids in the planning of individually optimized and cost-effective GH treatment.

  14. Bicycle Rider Control : Observations, Modeling & Experiments

    NARCIS (Netherlands)

    Kooijman, J.D.G.

    2012-01-01

    Bicycle designers traditionally develop bicycles based on experience and trial and error. Adopting modern engineering tools to model bicycle and rider dynamics and control is another method for developing bicycles. This method has the potential to evaluate the complete design space, and thereby

  15. Visual modelling suggests a weak relationship between the evolution of ultraviolet vision and plumage coloration in birds.

    Science.gov (United States)

    Lind, O; Delhey, K

    2015-03-01

    Birds have sophisticated colour vision mediated by four cone types that cover a wide visual spectrum including ultraviolet (UV) wavelengths. Many birds have modest UV sensitivity provided by violet-sensitive (VS) cones with sensitivity maxima between 400 and 425 nm. However, some birds have evolved higher UV sensitivity and a larger visual spectrum given by UV-sensitive (UVS) cones maximally sensitive at 360-370 nm. The reasons for VS-UVS transitions and their relationship to visual ecology remain unclear. It has been hypothesized that the evolution of UVS-cone vision is linked to plumage colours so that visual sensitivity and feather coloration are 'matched'. This leads to the specific prediction that UVS-cone vision enhances the discrimination of plumage colours of UVS birds while such an advantage is absent or less pronounced for VS-bird coloration. We test this hypothesis using knowledge of the complex distribution of UVS cones among birds combined with mathematical modelling of colour discrimination during different viewing conditions. We find no support for the hypothesis, which, combined with previous studies, suggests only a weak relationship between UVS-cone vision and plumage colour evolution. Instead, we suggest that UVS-cone vision generally favours colour discrimination, which creates a nonspecific selection pressure for the evolution of UVS cones. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

  16. Modeling Users' Experiences with Interactive Systems

    CERN Document Server

    Karapanos, Evangelos

    2013-01-01

    Over the past decade the field of Human-Computer Interaction has evolved from the study of the usability of interactive products towards a more holistic understanding of how they may mediate desired human experiences.  This book identifies the notion of diversity in usersʼ experiences with interactive products and proposes methods and tools for modeling this along two levels: (a) interpersonal diversity in usersʽ responses to early conceptual designs, and (b) the dynamics of usersʼ experiences over time. The Repertory Grid Technique is proposed as an alternative to standardized psychometric scales for modeling interpersonal diversity in usersʼ responses to early concepts in the design process, and new Multi-Dimensional Scaling procedures are introduced for modeling such complex quantitative data. iScale, a tool for the retrospective assessment of usersʼ experiences over time is proposed as an alternative to longitudinal field studies, and a semi-automated technique for the analysis of the elicited exper...

  17. Refining Grasp Affordance Models by Experience

    DEFF Research Database (Denmark)

    Detry, Renaud; Kraft, Dirk; Buch, Anders Glent

    2010-01-01

    grasps. These affordances are represented probabilistically with grasp densities, which correspond to continuous density functions defined on the space of 6D gripper poses. A grasp density characterizes an object’s grasp affordance; densities are linked to visual stimuli through registration...... with a visual model of the object they characterize. We explore a batch-oriented, experience-based learning paradigm where grasps sampled randomly from a density are performed, and an importance-sampling algorithm learns a refined density from the outcomes of these experiences. The first such learning cycle...

  18. Modeling variability in porescale multiphase flow experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Bowen; Bao, Jie; Oostrom, Mart; Battiato, Ilenia; Tartakovsky, Alexandre M.

    2017-07-01

    Microfluidic devices and porescale numerical models are commonly used to study multiphase flow in biological, geological, and engineered porous materials. In this work, we perform a set of drainage and imbibition experiments in six identical microfluidic cells to study the reproducibility of multiphase flow experiments. We observe significant variations in the experimental results, which are smaller during the drainage stage and larger during the imbibition stage. We demonstrate that these variations are due to sub-porescale geometry differences in microcells (because of manufacturing defects) and variations in the boundary condition (i.e.,fluctuations in the injection rate inherent to syringe pumps). Computational simulations are conducted using commercial software STAR-CCM+, both with constant and randomly varying injection rate. Stochastic simulations are able to capture variability in the experiments associated with the varying pump injection rate.

  19. Modeling variability in porescale multiphase flow experiments

    Science.gov (United States)

    Ling, Bowen; Bao, Jie; Oostrom, Mart; Battiato, Ilenia; Tartakovsky, Alexandre M.

    2017-07-01

    Microfluidic devices and porescale numerical models are commonly used to study multiphase flow in biological, geological, and engineered porous materials. In this work, we perform a set of drainage and imbibition experiments in six identical microfluidic cells to study the reproducibility of multiphase flow experiments. We observe significant variations in the experimental results, which are smaller during the drainage stage and larger during the imbibition stage. We demonstrate that these variations are due to sub-porescale geometry differences in microcells (because of manufacturing defects) and variations in the boundary condition (i.e., fluctuations in the injection rate inherent to syringe pumps). Computational simulations are conducted using commercial software STAR-CCM+, both with constant and randomly varying injection rates. Stochastic simulations are able to capture variability in the experiments associated with the varying pump injection rate.

  20. The erythrocyte sedimentation rates: some model experiments.

    Science.gov (United States)

    Cerny, L C; Cerny, E L; Granley, C R; Compolo, F; Vogels, M

    1988-01-01

    In order to obtain a better understanding of the erythrocyte sedimentation rate (ESR), several models are presented. The first directs attention to the importance of geometrical models to represent the structure of mixtures. Here it is our intention to understand the effect of the structure on the packing of red blood cells. In this part of the study, "Cheerios" (trademark General Mills) are used as a macroscopic model. It is interesting that a random sampling of "Cheerios" has the same volume distribution curve that is found for erythrocytes with a Coulter Sizing Apparatus. In order to examine the effect of rouleaux formation, the "Cheerios" are stacked one on top of another and then glued. Rouleaux of 2,3,4,5, 7 and 10 discs were used. In order to examine a more realistic biological model, the experiments of Dintenfass were used. These investigations were performed in a split-capillary photo viscometer using whole blood from patients with a variety of diseases. The novel part of this research is the fact that the work was performed at 1g and at near zero gravity in the space shuttle "Discovery." The size of the aggregates and/or rouleaux clearly showed a dependence upon the gravity of the experiment. The purpose of this model was to examine the condition of self-similarity and fractal behavior. Calculations are reported which clearly indicate that there is general agreement in the magnitude of the fractal dimension from the "Cheerios" model, the "Discovery" experiment with those determined with the automatic sedimentimeter. The final aspect of this work examines the surface texture of the sedimention tube. A series of tubes were designed with "roughened" interiors. A comparison of the sedimentation rates clearly indicates a more rapid settling in "roughened" tubes than in ones with a smooth interior surface.

  1. Skin care products can aggravate epidermal function: studies in a murine model suggest a pathogenic role in sensitive skin.

    Science.gov (United States)

    Li, Zhengxiao; Hu, Lizhi; Elias, Peter M; Man, Mao-Qiang

    2018-02-01

    Sensitive skin is defined as a spectrum of unpleasant sensations in response to a variety of stimuli. However, only some skin care products provoke cutaneous symptoms in individuals with sensitive skin. Hence, it would be useful to identify products that could provoke cutaneous symptoms in individuals with sensitive skin. To assess whether vehicles, as well as certain branded skin care products, can alter epidermal function following topical applications to normal mouse skin. Following topical applications of individual vehicle or skin care product to C57BL/6J mice twice daily for 4 days, transepidermal water loss (TEWL) rates, stratum corneum (SC) hydration and skin surface pH were measured on treated versus untreated mouse skin with an MPA5 device and pH 900 pH meter. Our results show that all tested products induced abnormalities in epidermal functions of varying severity, including elevations in TEWL and skin surface pH, and reduced SC hydration. Our results suggest that mice can serve as a predictive model that could be used to evaluate the potential safety of skin care products in humans with sensitive skin. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Genomic, RNAseq, and Molecular Modeling Evidence Suggests That the Major Allergen Domain in Insects Evolved from a Homodimeric Origin

    Science.gov (United States)

    Randall, Thomas A.; Perera, Lalith; London, Robert E.; Mueller, Geoffrey A.

    2013-01-01

    The major allergen domain (MA) is widely distributed in insects. The crystal structure of a single Bla g 1 MA revealed a novel protein fold in which the fundamental structure was a duplex of two subsequences (monomers), which had diverged over time. This suggested that the evolutionary origin of the MA structure may have been a homodimer of this smaller subsequence. Using publicly available genomic data, the distribution of the basic unit of this class of proteins was determined to better understand its evolutionary history. The duplication and divergence is examined at three distinct levels of resolution: 1) within the orders Diptera and Hymenoptera, 2) within one genus Drosophila, and 3) within one species Aedes aegypti. Within the family Culicidae, we have found two separate occurrences of monomers as independent genes. The organization of the gene family in A. aegypti shows a common evolutionary origin for its monomer and several closely related MAs. Molecular modeling of the A. aegypti monomer with the unique Bla g 1 fold confirms the distant evolutionary relationship and supports the feasibility of homodimer formation from a single monomer. RNAseq data for A. aegypti confirms that the monomer is expressed in the mosquito similar to other A. aegypti MAs after a blood meal. Together, these data support the contention that the detected monomer shares similar functional characteristics to related MAs in other insects. An extensive search for this domain outside of Insecta confirms that the MAs are restricted to insects. PMID:24253356

  3. Nonhomologous recombination between defective poliovirus and coxsackievirus genomes suggests a new model of genetic plasticity for picornaviruses.

    Science.gov (United States)

    Holmblat, Barbara; Jégouic, Sophie; Muslin, Claire; Blondel, Bruno; Joffret, Marie-Line; Delpeyroux, Francis

    2014-08-05

    Most of the circulating vaccine-derived polioviruses (cVDPVs) implicated in poliomyelitis outbreaks in Madagascar have been shown to be recombinants between the type 2 poliovirus (PV) strain of the oral polio vaccine (Sabin 2) and another species C human enterovirus (HEV-C), such as type 17 coxsackie A virus (CA17) in particular. We studied intertypic genetic exchanges between PV and non-PV HEV-C by developing a recombination model, making it possible to rescue defective type 2 PV RNA genomes with a short deletion at the 3' end by the cotransfection of cells with defective or infectious CA17 RNAs. We isolated over 200 different PV/CA17 recombinants, using murine cells expressing the human PV receptor (PVR) and selecting viruses with PV capsids. We found some homologous (H) recombinants and, mostly, nonhomologous (NH) recombinants presenting duplications of parental sequences preferentially located in the regions encoding proteins 2A, 2B, and 3A. Short duplications appeared to be stable, whereas longer duplications were excised during passaging in cultured cells or after multiplication in PVR-transgenic mice, generating H recombinants with diverse sites of recombination. This suggests that NH recombination events may be a transient, intermediate step in the generation and selection of the fittest H recombinants. In addition to the classical copy-choice mechanism of recombination thought to generate mostly H recombinants, there may also be a modular mechanism of recombination, involving NH recombinant precursors, shaping the genomes of recombinant enteroviruses and other picornaviruses. Importance: The multiplication of circulating vaccine-derived polioviruses (cVDPVs) in poorly immunized human populations can render these viruses pathogenic, causing poliomyelitis outbreaks. Most cVDPVs are intertypic recombinants between a poliovirus (PV) strain and another human enterovirus, such as type 17 coxsackie A viruses (CA17). For further studies of the genetic exchanges

  4. Debris Thermal Hydraulics Modeling of QUENCH Experiments

    International Nuclear Information System (INIS)

    Kisselev, Arcadi E.; Kobelev, Gennadii V.; Strizhov, Valerii F.; Vasiliev, Alexander D.

    2006-01-01

    Porous debris formation and behavior in QUENCH experiments (QUENCH-02, QUENCH-03) plays a considerable role and its adequate modeling is important for thermal analysis. This work is aimed to the development of a numerical module which is able to model thermal hydraulics and heat transfer phenomena occurring during the high-temperature stage of severe accident with the formation of debris region and molten pool. The original approach for debris evolution is developed from classical principles using a set of parameters including debris porosity; average particle diameter; temperatures and mass fractions of solid, liquid and gas phases; specific interface areas between different phases; effective thermal conductivity of each phase, including radiative heat conductivity; mass and energy fluxes through the interfaces. The debris model is based on the system of continuity, momentum and energy conservation equations, which consider the dynamics of volume-averaged velocities and temperatures of fluid, solid and gaseous phases of porous debris. The different mechanisms of debris formation are considered, including degradation of fuel rods according to temperature criteria, taking into consideration some correlations between rod layers thicknesses; degradation of rod layer structure due to thermal expansion of melted materials inside intact rod cladding; debris formation due to sharp temperature drop of previously melted material due to reflood; and transition to debris of material from elements lying above. The porous debris model was implemented to best estimate numerical code RATEG/SVECHA/HEFEST developed for modeling thermal hydraulics and severe accident phenomena in a reactor. The model is used for calculation of QUENCH experiments. The results obtained by the model are compared to experimental data concerning different aspects of thermal behavior: thermal hydraulics of porous debris, radiative heat transfer in a porous medium, the generalized melting and refreezing

  5. Nonhomologous Recombination between Defective Poliovirus and Coxsackievirus Genomes Suggests a New Model of Genetic Plasticity for Picornaviruses

    Science.gov (United States)

    Holmblat, Barbara; Jégouic, Sophie; Muslin, Claire; Blondel, Bruno; Joffret, Marie-Line

    2014-01-01

    ABSTRACT Most of the circulating vaccine-derived polioviruses (cVDPVs) implicated in poliomyelitis outbreaks in Madagascar have been shown to be recombinants between the type 2 poliovirus (PV) strain of the oral polio vaccine (Sabin 2) and another species C human enterovirus (HEV-C), such as type 17 coxsackie A virus (CA17) in particular. We studied intertypic genetic exchanges between PV and non-PV HEV-C by developing a recombination model, making it possible to rescue defective type 2 PV RNA genomes with a short deletion at the 3′ end by the cotransfection of cells with defective or infectious CA17 RNAs. We isolated over 200 different PV/CA17 recombinants, using murine cells expressing the human PV receptor (PVR) and selecting viruses with PV capsids. We found some homologous (H) recombinants and, mostly, nonhomologous (NH) recombinants presenting duplications of parental sequences preferentially located in the regions encoding proteins 2A, 2B, and 3A. Short duplications appeared to be stable, whereas longer duplications were excised during passaging in cultured cells or after multiplication in PVR-transgenic mice, generating H recombinants with diverse sites of recombination. This suggests that NH recombination events may be a transient, intermediate step in the generation and selection of the fittest H recombinants. In addition to the classical copy-choice mechanism of recombination thought to generate mostly H recombinants, there may also be a modular mechanism of recombination, involving NH recombinant precursors, shaping the genomes of recombinant enteroviruses and other picornaviruses. PMID:25096874

  6. Argonne Bubble Experiment Thermal Model Development III

    Energy Technology Data Exchange (ETDEWEB)

    Buechler, Cynthia Eileen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-01-11

    This report describes the continuation of the work reported in “Argonne Bubble Experiment Thermal Model Development” and “Argonne Bubble Experiment Thermal Model Development II”. The experiment was performed at Argonne National Laboratory (ANL) in 2014. A rastered 35 MeV electron beam deposited power in a solution of uranyl sulfate, generating heat and radiolytic gas bubbles. Irradiations were performed at beam power levels between 6 and 15 kW. Solution temperatures were measured by thermocouples, and gas bubble behavior was recorded. The previous report2 described the Monte-Carlo N-Particle (MCNP) calculations and Computational Fluid Dynamics (CFD) analysis performed on the as-built solution vessel geometry. The CFD simulations in the current analysis were performed using Ansys Fluent, Ver. 17.2. The same power profiles determined from MCNP calculations in earlier work were used for the 12 and 15 kW simulations. The primary goal of the current work is to calculate the temperature profiles for the 12 and 15 kW cases using reasonable estimates for the gas generation rate, based on images of the bubbles recorded during the irradiations. Temperature profiles resulting from the CFD calculations are compared to experimental measurements.

  7. The 'OMITRON' and 'MODEL OMITRON' proposed experiments

    International Nuclear Information System (INIS)

    Sestero, A.

    1997-12-01

    In the present paper the main features of the OMITRON and MODEL OMITRON proposed high field tokamaks are illustrated. Of the two, OMITRON is an ambitious experiment, aimed at attaining plasma burning conditions. its key physics issues are discussed, and a comparison is carried out with corresponding physics features in ignition experiments such as IGNITOR and ITER. Chief asset and chief challenge - in both OMITRON and MODEL OMITRON is the conspicuous 20 Tesla toroidal field value on the plasma axis. The advanced features of engineering which consent such a reward in terms of toroidal magnet performance are discussed in convenient depth and detail. As for the small, propaedeutic device MODEL OMITRON among its goals one must rank the purpose of testing key engineering issues in vivo, which are vital for the larger and more expensive parent device. Besides that, however - as indicated by ad hoc performed scoping studies - the smaller machine is found capable also of a number of quite interesting physics investigations in its own right

  8. Low modeled ozone production suggests underestimation of precursor emissions (especially NOx) in Europe

    OpenAIRE

    E. Oikonomakis; S. Aksoyoglu; G. Ciarelli; U. Baltensperger; A. S. H. Prévôt

    2018-01-01

    High surface ozone concentrations, which usually occur when photochemical ozone production takes place, pose a great risk to human health and vegetation. Air quality models are often used by policy makers as tools for the development of ozone mitigation strategies. However, the modeled ozone production is often not or not enough evaluated in many ozone modeling studies. The focus of this work is to evaluate the modeled ozone production in Europe indirectly, with the use of t...

  9. A proposed experiment on ball lightning model

    Energy Technology Data Exchange (ETDEWEB)

    Ignatovich, Vladimir K., E-mail: v.ignatovi@gmail.com [Frank Laboratory for Neutron Physics, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Ignatovich, Filipp V. [1565 Jefferson Rd., 420, Rochester, NY 14623 (United States)

    2011-09-19

    Highlights: → We propose to put a glass sphere inside an excited gas. → Then to put a light ray inside the glass in a whispering gallery mode. → If the light is resonant to gas excitation, it will be amplified at every reflection. → In ms time the light in the glass will be amplified, and will melt the glass. → A liquid shell kept integer by electrostriction forces is the ball lightning model. -- Abstract: We propose an experiment for strong light amplification at multiple total reflections from active gaseous media.

  10. Experiments for foam model development and validation.

    Energy Technology Data Exchange (ETDEWEB)

    Bourdon, Christopher Jay; Cote, Raymond O.; Moffat, Harry K.; Grillet, Anne Mary; Mahoney, James F. (Honeywell Federal Manufacturing and Technologies, Kansas City Plant, Kansas City, MO); Russick, Edward Mark; Adolf, Douglas Brian; Rao, Rekha Ranjana; Thompson, Kyle Richard; Kraynik, Andrew Michael; Castaneda, Jaime N.; Brotherton, Christopher M.; Mondy, Lisa Ann; Gorby, Allen D.

    2008-09-01

    A series of experiments has been performed to allow observation of the foaming process and the collection of temperature, rise rate, and microstructural data. Microfocus video is used in conjunction with particle image velocimetry (PIV) to elucidate the boundary condition at the wall. Rheology, reaction kinetics and density measurements complement the flow visualization. X-ray computed tomography (CT) is used to examine the cured foams to determine density gradients. These data provide input to a continuum level finite element model of the blowing process.

  11. Experience with the CMS Event Data Model

    Energy Technology Data Exchange (ETDEWEB)

    Elmer, P.; /Princeton U.; Hegner, B.; /CERN; Sexton-Kennedy, L.; /Fermilab

    2009-06-01

    The re-engineered CMS EDM was presented at CHEP in 2006. Since that time we have gained a lot of operational experience with the chosen model. We will present some of our findings, and attempt to evaluate how well it is meeting its goals. We will discuss some of the new features that have been added since 2006 as well as some of the problems that have been addressed. Also discussed is the level of adoption throughout CMS, which spans the trigger farm up to the final physics analysis. Future plans, in particular dealing with schema evolution and scaling, will be discussed briefly.

  12. Implementation of the model project: Ghanaian experience

    International Nuclear Information System (INIS)

    Schandorf, C.; Darko, E.O.; Yeboah, J.; Asiamah, S.D.

    2003-01-01

    Upgrading of the legal infrastructure has been the most time consuming and frustrating part of the implementation of the Model project due to the unstable system of governance and rule of law coupled with the low priority given to legislation on technical areas such as safe applications of Nuclear Science and Technology in medicine, industry, research and teaching. Dwindling Governmental financial support militated against physical and human resource infrastructure development and operational effectiveness. The trend over the last five years has been to strengthen the revenue generation base of the Radiation Protection Institute through good management practices to ensure a cost effective use of the limited available resources for a self-reliant and sustainable radiation and waste safety programme. The Ghanaian experience regarding the positive and negative aspects of the implementation of the Model Project is highlighted. (author)

  13. Bucky gel actuator displacement: experiment and model

    International Nuclear Information System (INIS)

    Ghamsari, A K; Zegeye, E; Woldesenbet, E; Jin, Y

    2013-01-01

    Bucky gel actuator (BGA) is a dry electroactive nanocomposite which is driven with a few volts. BGA’s remarkable features make this tri-layered actuator a potential candidate for morphing applications. However, most of these applications would require a better understanding of the effective parameters that influence the BGA displacement. In this study, various sets of experiments were designed to investigate the effect of several parameters on the maximum lateral displacement of BGA. Two input parameters, voltage and frequency, and three material/design parameters, carbon nanotube type, thickness, and weight fraction of constituents were selected. A new thickness ratio term was also introduced to study the role of individual layers on BGA displacement. A model was established to predict BGA maximum displacement based on the effect of these parameters. This model showed good agreement with reported results from the literature. In addition, an important factor in the design of BGA-based devices, lifetime, was investigated. (paper)

  14. Forces between permanent magnets: experiments and model

    International Nuclear Information System (INIS)

    González, Manuel I

    2017-01-01

    This work describes a very simple, low-cost experimental setup designed for measuring the force between permanent magnets. The experiment consists of placing one of the magnets on a balance, attaching the other magnet to a vertical height gauge, aligning carefully both magnets and measuring the load on the balance as a function of the gauge reading. A theoretical model is proposed to compute the force, assuming uniform magnetisation and based on laws and techniques accessible to undergraduate students. A comparison between the model and the experimental results is made, and good agreement is found at all distances investigated. In particular, it is also found that the force behaves as r −4 at large distances, as expected. (paper)

  15. Forces between permanent magnets: experiments and model

    Science.gov (United States)

    González, Manuel I.

    2017-03-01

    This work describes a very simple, low-cost experimental setup designed for measuring the force between permanent magnets. The experiment consists of placing one of the magnets on a balance, attaching the other magnet to a vertical height gauge, aligning carefully both magnets and measuring the load on the balance as a function of the gauge reading. A theoretical model is proposed to compute the force, assuming uniform magnetisation and based on laws and techniques accessible to undergraduate students. A comparison between the model and the experimental results is made, and good agreement is found at all distances investigated. In particular, it is also found that the force behaves as r -4 at large distances, as expected.

  16. Modeling reproducibility of porescale multiphase flow experiments

    Science.gov (United States)

    Ling, B.; Tartakovsky, A. M.; Bao, J.; Oostrom, M.; Battiato, I.

    2017-12-01

    Multi-phase flow in porous media is widely encountered in geological systems. Understanding immiscible fluid displacement is crucial for processes including, but not limited to, CO2 sequestration, non-aqueous phase liquid contamination and oil recovery. Microfluidic devices and porescale numerical models are commonly used to study multiphase flow in biological, geological, and engineered porous materials. In this work, we perform a set of drainage and imbibition experiments in six identical microfluidic cells to study the reproducibility of multiphase flow experiments. We observe significant variations in the experimental results, which are smaller during the drainage stage and larger during the imbibition stage. We demonstrate that these variations are due to sub-porescale geometry differences in microcells (because of manufacturing defects) and variations in the boundary condition (i.e.,fluctuations in the injection rate inherent to syringe pumps). Computational simulations are conducted using commercial software STAR-CCM+, both with constant and randomly varying injection rate. Stochastic simulations are able to capture variability in the experiments associated with the varying pump injection rate.

  17. Mathematical Model of Nicholson’s Experiment

    Directory of Open Access Journals (Sweden)

    Sergey D. Glyzin

    2017-01-01

    Full Text Available Considered  is a mathematical model of insects  population dynamics,  and  an attempt is made  to explain  classical experimental results  of Nicholson with  its help.  In the  first section  of the paper  Nicholson’s experiment is described  and dynamic  equations  for its modeling are chosen.  A priori estimates  for model parameters can be made more precise by means of local analysis  of the  dynamical system,  that is carried  out in the second section.  For parameter values found there  the stability loss of the  problem  equilibrium  of the  leads to the  bifurcation of a stable  two-dimensional torus.   Numerical simulations  based  on the  estimates  from the  second section  allows to explain  the  classical Nicholson’s experiment, whose detailed  theoretical substantiation is given in the last section.  There for an atrractor of the  system  the  largest  Lyapunov  exponent is computed. The  nature of this  exponent change allows to additionally narrow  the area of model parameters search.  Justification of this experiment was made possible  only  due  to  the  combination of analytical and  numerical  methods  in studying  equations  of insects  population dynamics.   At the  same time,  the  analytical approach made  it possible to perform numerical  analysis  in a rather narrow  region of the  parameter space.  It is not  possible to get into this area,  based only on general considerations.

  18. Wedge Experiment Modeling and Simulation for Reactive Flow Model Calibration

    Science.gov (United States)

    Maestas, Joseph T.; Dorgan, Robert J.; Sutherland, Gerrit T.

    2017-06-01

    Wedge experiments are a typical method for generating pop-plot data (run-to-detonation distance versus input shock pressure), which is used to assess an explosive material's initiation behavior. Such data can be utilized to calibrate reactive flow models by running hydrocode simulations and successively tweaking model parameters until a match between experiment is achieved. Typical simulations are performed in 1D and typically use a flyer impact to achieve the prescribed shock loading pressure. In this effort, a wedge experiment performed at the Army Research Lab (ARL) was modeled using CTH (SNL hydrocode) in 1D, 2D, and 3D space in order to determine if there was any justification in using simplified models. A simulation was also performed using the BCAT code (CTH companion tool) that assumes a plate impact shock loading. Results from the simulations were compared to experimental data and show that the shock imparted into an explosive specimen is accurately captured with 2D and 3D simulations, but changes significantly in 1D space and with the BCAT tool. The difference in shock profile is shown to only affect numerical predictions for large run distances. This is attributed to incorrectly capturing the energy fluence for detonation waves versus flat shock loading. Portions of this work were funded through the Joint Insensitive Munitions Technology Program.

  19. Thermal Properties of Metallic Nanowires: Modeling & Experiment

    Science.gov (United States)

    Stojanovic, Nenad; Berg, Jordan; Maithripala, Sanjeeva; Holtz, Mark

    2009-10-01

    Effects such as surface and grain boundary scattering significantly influence electrical and thermal properties of nanoscale materials with important practical implications for current and future electronics and photonics. Conventional wisdom for metals holds that thermal transport is predominantly by electrons and transport by phonons is negligible. This assumption is used to justify the use of the Wiedemann-Franz law to infer thermal conductivity based on measurements of electrical resistivity. Recently experiments suggest a breakdown of the Wiedemann-Franz law at the nanoscale. This talk will examine the assumption that thermal transport by phonons can be neglected. The electrical resistivities and thermal conductivities of aluminum nanowires of various sizes are directly measured. These values are used in conjunction with the Boltzmann transport equation to conclude that the Wiedemann-Franz law describes the electronic component of thermal conductivity, but that the phonon term must also be considered. A novel experimental device is described for the direct thermal conductivity measurements.

  20. [Experience of implementing a primary attention model].

    Science.gov (United States)

    Ruiz-Rodríguez, Myriam; Acosta-Ramírez, Naydú; Rodríguez Villamizar, Laura A; Uribe, Luz M; León-Franco, Martha

    2011-12-01

    Identifying barriers and dynamic factors in setting up a primary health care (PHC) model in the Santander department during the last decade. This was a qualitative study, focusing on pluralism and triangulating sources and actors, with a critical analysis of limits and judgments values (boundary critique). Philosophical/conceptual and operational management problems were found from the emergent categories related to appropriating PHC attributes. The theoretical model design was in fact not developed in practice. The PHC strategy is selective and state-led (at department level), focusing on rural interventions developed by nursing assistants and orientated towards fulfilling public health goals in the first healthcare level. Difficulties at national, state and local level were identified which could be useful in other national and international contexts. Structural healthcare system market barriers were the most important constraints since the model operates through the contractual logic of institutional segmentation and operational fragmentation. Human resource management focusing on skills, suitable local health management and systematic evaluation studies would thus be suggested as essential operational elements for facing the aforementioned problems and encourage an integral PHC model in Colombia.

  1. Low apparent quantum yield in Arctic plants suggests that terrestrial biosphere models will over estimate carbon assimilation at high latitudes

    Science.gov (United States)

    Rogers, A.; Serbin, S.; Ely, K.; Wullschleger, S.

    2017-12-01

    Estimates of Gross Primary Productivity (GPP) by terrestrial biosphere models (TBMs) rely on accurate model representation of photosynthesis. In the Arctic, TBM uncertainty over GPP is the dominant driver of an uncertain Arctic carbon cycle. Previously we have shown that TBMs underestimate light saturated photosynthesis due to poor model representation of maximum carboxylation capacity and maximum electron transport. Here we extend this work to investigate model representation of the response of photosynthesis to irradiance. TBMs use an empirical relationship, typically a non-rectangular hyperbola, to estimate potential electron transport rate from incident irradiance. The key model inputs used to parameterize this formulation are; absorptance, quantum yield, and a curvature factor. TBMs show a high divergence in the response of photosynthesis to irradiance driven in part by variation in these parameters. In addition, most existing measurements used to parameterize TBMs have been made within a narrow temperature range (20-30°C) and the scarcity of data collected at low temperature has been highlighted as an important driver of model uncertainty at high latitudes. To address this issue we measured photosynthetic light response curves at 5 and 15°C and the leaf optical properties of six species growing on the Barrow Environmental Observatory, Barrow, Alaska. We determined leaf absorbtance, the convexity term, and apparent quantum yield. Our key finding was that measured apparent quantum yield was lower than model estimates, particularly at 5°C. Our results show that TBMs that rely on relatively high theoretical estimates of apparent quantum yield will likely overestimate carbon assimilation at low temperature and low irradiance.

  2. Klimaschutz in China. Summary of experience from the existing environmental law relating to climate change and suggestions for China's climate change legislation

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Mingde [China Univ. of Political Science and Law, Peking (China). Climate Change and Natural Resources Law Center

    2014-07-01

    , more than ten climate change convention documents, more than forty laws, more than eighty administrative regulations and more than one hundred and seventy rules. This study examines Chinese laws and policies on climate change, and evaluates their legal effect. This essay summarizes as follows from two aspects: existing experience of laws and policies and successful institutions, and suggestions for future climate change legislation.

  3. Klimaschutz in China. Summary of experience from the existing environmental law relating to climate change and suggestions for China's climate change legislation

    International Nuclear Information System (INIS)

    Cao, Mingde

    2014-01-01

    ten climate change convention documents, more than forty laws, more than eighty administrative regulations and more than one hundred and seventy rules. This study examines Chinese laws and policies on climate change, and evaluates their legal effect. This essay summarizes as follows from two aspects: existing experience of laws and policies and successful institutions, and suggestions for future climate change legislation.

  4. Low Energy Atomic Models Suggesting a Pilus Structure that could Account for Electrical Conductivity of Geobacter sulfurreducens Pili.

    Science.gov (United States)

    Xiao, Ke; Malvankar, Nikhil S; Shu, Chuanjun; Martz, Eric; Lovley, Derek R; Sun, Xiao

    2016-03-22

    The metallic-like electrical conductivity of Geobacter sulfurreducens pili has been documented with multiple lines of experimental evidence, but there is only a rudimentary understanding of the structural features which contribute to this novel mode of biological electron transport. In order to determine if it was feasible for the pilin monomers of G. sulfurreducens to assemble into a conductive filament, theoretical energy-minimized models of Geobacter pili were constructed with a previously described approach, in which pilin monomers are assembled using randomized structural parameters and distance constraints. The lowest energy models from a specific group of predicted structures lacked a central channel, in contrast to previously existing pili models. In half of the no-channel models the three N-terminal aromatic residues of the pilin monomer are arranged in a potentially electrically conductive geometry, sufficiently close to account for the experimentally observed metallic like conductivity of the pili that has been attributed to overlapping pi-pi orbitals of aromatic amino acids. These atomic resolution models capable of explaining the observed conductive properties of Geobacter pili are a valuable tool to guide further investigation of the metallic-like conductivity of the pili, their role in biogeochemical cycling, and applications in bioenergy and bioelectronics.

  5. Didactical suggestion for a Dynamic Hybrid Intelligent e-Learning Environment (DHILE) applying the PENTHA ID Model

    Science.gov (United States)

    dall'Acqua, Luisa

    2011-08-01

    The teleology of our research is to propose a solution to the request of "innovative, creative teaching", proposing a methodology to educate creative Students in a society characterized by multiple reference points and hyper dynamic knowledge, continuously subject to reviews and discussions. We apply a multi-prospective Instructional Design Model (PENTHA ID Model), defined and developed by our research group, which adopts a hybrid pedagogical approach, consisting of elements of didactical connectivism intertwined with aspects of social constructivism and enactivism. The contribution proposes an e-course structure and approach, applying the theoretical design principles of the above mentioned ID Model, describing methods, techniques, technologies and assessment criteria for the definition of lesson modes in an e-course.

  6. Bifurcation Analysis of an Existing Mathematical Model Reveals Novel Treatment Strategies and Suggests Potential Cure for Type 1 Diabetes

    DEFF Research Database (Denmark)

    Nielsen, Kenneth Hagde Mandrup; Ottesen, Johnny T.; Pociot, Flemming

    2014-01-01

    Type 1 diabetes is a disease with serious personal and socioeconomic consequences that has attracted the attention of modellers recently. But as models of this disease tend to be complicated, there has been only limited mathematical analysis to date. Here we address this problem by providing...... a bifurcation analysis of a previously published mathematical model for the early stages of type 1 diabetes in diabetes-prone NOD mice, which is based on the data available in the literature. We also show positivity and the existence of a family of attracting trapping regions in the positive 5D cone, converging...... towards a smaller trapping region, which is the intersection over the family. All these trapping regions are compact sets, and thus, practical weak persistence is guaranteed. We conclude our analysis by proposing 4 novel treatment strategies: increasing the phagocytic ability of resting macrophages...

  7. Photogrammetry experiments with a model eye.

    Science.gov (United States)

    Rosenthal, A R; Falconer, D G; Pieper, I

    1980-01-01

    Digital photogrammetry was performed on stereophotographs of the optic nerve head of a modified Zeiss model eye in which optic cups of varying depths could be simulated. Experiments were undertaken to determine the impact of both photographic and ocular variables on the photogrammetric measurements of cup depth. The photogrammetric procedure tolerates refocusing, repositioning, and realignment as well as small variations in the geometric position of the camera. Progressive underestimation of cup depth was observed with increasing myopia, while progressive overestimation was noted with increasing hyperopia. High cylindrical errors at axis 90 degrees led to significant errors in cup depth estimates, while high cylindrical errors at axis 180 degrees did not materially affect the accuracy of the analysis. Finally, cup depths were seriously underestimated when the pupil diameter was less than 5.0 mm. Images PMID:7448139

  8. Comparative modeling and molecular dynamics suggest high carboxylase activity of the Cyanobium sp. CACIAM14 RbcL protein.

    Science.gov (United States)

    Siqueira, Andrei Santos; Lima, Alex Ranieri Jerônimo; Dall'Agnol, Leonardo Teixeira; de Azevedo, Juliana Simão Nina; da Silva Gonçalves Vianez, João Lídio; Gonçalves, Evonnildo Costa

    2016-03-01

    Rubisco catalyzes the first step reaction in the carbon fixation pathway, bonding atmospheric CO2/O2 to ribulose 1,5-bisphosphate; it is therefore considered one of the most important enzymes in the biosphere. Genetic modifications to increase the carboxylase activity of rubisco are a subject of great interest to agronomy and biotechnology, since this could increase the productivity of biomass in plants, algae and cyanobacteria and give better yields in crops and biofuel production. Thus, the aim of this study was to characterize in silico the catalytic domain of the rubisco large subunit (rbcL gene) of Cyanobium sp. CACIAM14, and identify target sites to improve enzyme affinity for ribulose 1,5-bisphosphate. A three-dimensional model was built using MODELLER 9.14, molecular dynamics was used to generate a 100 ns trajectory by AMBER12, and the binding free energy was calculated using MM-PBSA, MM-GBSA and SIE methods with alanine scanning. The model obtained showed characteristics of form-I rubisco, with 15 beta sheets and 19 alpha helices, and maintained the highly conserved catalytic site encompassing residues Lys175, Lys177, Lys201, Asp203, and Glu204. The binding free energy of the enzyme-substrate complexation of Cyanobium sp. CACIAM14 showed values around -10 kcal mol(-1) using the SIE method. The most important residues for the interaction with ribulose 1,5-bisphosphate were Arg295 followed by Lys334. The generated model was successfully validated, remaining stable during the whole simulation, and demonstrated characteristics of enzymes with high carboxylase activity. The binding analysis revealed candidates for directed mutagenesis sites to improve rubisco's affinity.

  9. Synthetic biology between challenges and risks: suggestions for a model of governance and a regulatory framework, based on fundamental rights.

    Science.gov (United States)

    Colussi, Ilaria Anna

    2013-01-01

    This paper deals with the emerging synthetic biology, its challenges and risks, and tries to design a model for the governance and regulation of the field. The model is called of "prudent vigilance" (inspired by the report about synthetic biology, drafted by the U.S. Presidential Commission on Bioethics, 2010), and it entails (a) an ongoing and periodically revised process of assessment and management of all the risks and concerns, and (b) the adoption of policies - taken through "hard law" and "soft law" sources - that are based on the principle of proportionality (among benefits and risks), on a reasonable balancing between different interests and rights at stake, and are oriented by a constitutional frame, which is represented by the protection of fundamental human rights emerging in the field of synthetic biology (right to life, right to health, dignity, freedom of scientific research, right to environment). After the theoretical explanation of the model, its operability is "checked", by considering its application with reference to only one specific risk brought up by synthetic biology - biosecurity risk, i.e. the risk of bioterrorism.

  10. Analysis and modeling of heat-labile enterotoxins of Escherichia coli suggests a novel space with insights into receptor preference.

    Science.gov (United States)

    Krishna Raja, M; Ghosh, Asit Ranjan; Vino, S; Sajitha Lulu, S

    2015-01-01

    Features of heat-labile enterotoxins of Escherichia coli which make them fit to use as novel receptors for antidiarrheals are not completely explored. Data-set of 14 different serovars of enterotoxigenic Escherichia coli producing heat-labile toxins were taken from NCBI Genbank database and used in the study. Sequence analysis showed mutations in different subunits and also at their interface residues. As these toxins lack crystallography structures, homology modeling using Modeller 9.11 led to the structural approximation for the E. coli producing heat-labile toxins. Interaction of modeled toxin subunits with proanthocyanidin, an antidiarrheal showed several strong hydrogen bonding interactions at the cost of minimized energy. The hits were subsequently characterized by molecular dynamics simulation studies to monitor their binding stabilities. This study looks into novel space where the ligand can choose the receptor preference not as a whole but as an individual subunit. Mutation at interface residues and interaction among subunits along with the binding of ligand to individual subunits would help to design a non-toxic labile toxin and also to improve the therapeutics.

  11. Shock, release and reshock of PBX 9502: experiments and modeling

    Science.gov (United States)

    Aslam, Tariq; Gustavsen, Richard; Whitworh, Nicholas; Menikoff, Ralph; Tarver, Craig; Handley, Caroline; Bartram, Brian

    2017-06-01

    We examine shock, release and reshock into the tri-amino-tri-nitro-benzene (TATB) based explosive PBX 9502 (95% TATB, 5% Kel-F 800) from both an experimental and modeling point of view. The experiments are performed on the 2-stage light gas gun at Los Alamos National Laboratory and are composed of a multi-layered impactor impinging on PBX 9502 backed by a polymethylmethacrylate window. The objective is to initially shock the PBX 9502 in the 7 GPa range (too weak to start significant reaction), then allow a rarefaction fan to release the material to a lower pressure/temperature state. Following this release, a strong second shock will recompress the PBX. If the rarefaction fan releases the PBX to a very low pressure, the ensuing second shock can increase the entropy and temperature substantially more than in previous double-shock experiments without an intermediate release. Predictions from a variety of reactive burn models (AWSD, CREST, Ignition and Growth, SURF) demonstrate significantly different behaviors and thus the experiments are an excellent validation test of the models, and may suggest improvements for subsequent modeling efforts.

  12. Bioinformatic analysis and molecular modelling of human ameloblastin suggest a two-domain intrinsically unstructured calcium-binding protein

    Czech Academy of Sciences Publication Activity Database

    Vymětal, Jiří; Slabý, I.; Spahr, A.; Vondrášek, Jiří; Lyngstadaas, S. P.

    2008-01-01

    Roč. 116, č. 2 (2008), s. 124-134 ISSN 0909-8836 R&D Projects: GA ČR GA203/05/0009; GA ČR GA203/06/1727; GA MŠk LC512 Grant - others:EU(XE) QLK3-CT-2001-00090 Institutional research plan: CEZ:AV0Z40550506 Keywords : ameloblastin * bioinformatic modelling * calcium * intrinsically unstructured protein Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.957, year: 2008

  13. Global models of ant diversity suggest regions where new discoveries are most likely are under disproportionate deforestation threat.

    Science.gov (United States)

    Guénard, Benoit; Weiser, Michael D; Dunn, Robert R

    2012-05-08

    Most of the described and probably undescribed species on Earth are insects. Global models of species diversity rarely focus on insects and none attempt to address unknown, undescribed diversity. We assembled a database representing about 13,000 records for ant generic distribution from over 350 regions that cover much of the globe. Based on two models of diversity and endemicity, we identified regions where our knowledge of ant diversity is most limited, regions we have called "hotspots of discovery." A priori, such regions might be expected to be remote and untouched. Instead, we found that the hotspots of discovery are also the regions in which biodiversity is the most threatened by habitat destruction. Our results not only highlight the immediate need for conservation of the remaining natural habitats in these regions, but also the extent to which, by focusing on well-known groups such as vertebrates, we may fail to conserve the far greater diversity of the smaller species yet to be found.

  14. Paired octamer rings of retinoschisin suggest a junctional model for cell–cell adhesion in the retina

    Science.gov (United States)

    Tolun, Gökhan; Vijayasarathy, Camasamudram; Huang, Rick; Zeng, Yong; Li, Yan; Steven, Alasdair C.; Sieving, Paul A.

    2016-01-01

    Retinoschisin (RS1) is involved in cell–cell junctions in the retina, but is unique among known cell-adhesion proteins in that it is a soluble secreted protein. Loss-of-function mutations in RS1 lead to early vision impairment in young males, called X-linked retinoschisis. The disease is characterized by separation of inner retinal layers and disruption of synaptic signaling. Using cryo-electron microscopy, we report the structure at 4.1 Å, revealing double octamer rings not observed before. Each subunit is composed of a discoidin domain and a small N-terminal (RS1) domain. The RS1 domains occupy the centers of the rings, but are not required for ring formation and are less clearly defined, suggesting mobility. We determined the structure of the discoidin rings, consistent with known intramolecular and intermolecular disulfides. The interfaces internal to and between rings feature residues implicated in X-linked retinoschisis, indicating the importance of correct assembly. Based on this structure, we propose that RS1 couples neighboring membranes together through octamer–octamer contacts, perhaps modulated by interactions with other membrane components. PMID:27114531

  15. Ceramic bar impact experiments for improved material model

    International Nuclear Information System (INIS)

    Brar, N.S.; Proud, W.G.; Rajendran, A.M.

    2004-01-01

    Ceramic bar-on-bar (uniaxial stress) experiments are performed to extend uniaxial strain deformation states imposed in flyer plate impact experiments. A number of investigators engaged in modeling the bar-on-bar experiments have varying degrees of success in capturing the observed fracture modes in bars and correctly simulating the measured in-situ axial stress or free surface velocity histories. The difficulties encountered are related to uncertainties in understanding the dominant failure mechanisms as a function of different stress states imposed in bar impacts. Free surface velocity of the far end of the target AD998 bar were measured using a VISAR in a series of bar-on-bar impact experiments at nominal impact speeds of 100 m/s, 220 m/s, and 300 m/s. Velocity history data at an impact of 100 m/s show the material response as elastic. At higher impact velocities of 200 m/s and 300 m/s the velocity history data suggest an inelastic material response. A high-speed (Imacon) camera was employed to examine the fracture and failure of impactor and target bars. High speed photographs provide comprehensive data on geometry of damage and failure patterns as a function of time to check the validity of a particular constitutive material model for AD998 alumina used in numerical simulations of fracture and failure of the bars on impact

  16. The modeled structure of the RNA dependent RNA polymerase of GBV-C Virus suggests a role for motif E in Flaviviridae RNA polymerases

    Directory of Open Access Journals (Sweden)

    Dutartre Hélène

    2005-10-01

    Full Text Available Abstract Background The Flaviviridae virus family includes major human and animal pathogens. The RNA dependent RNA polymerase (RdRp plays a central role in the replication process, and thus is a validated target for antiviral drugs. Despite the increasing structural and enzymatic characterization of viral RdRps, detailed molecular replication mechanisms remain unclear. The hepatitis C virus (HCV is a major human pathogen difficult to study in cultured cells. The bovine viral diarrhea virus (BVDV is often used as a surrogate model to screen antiviral drugs against HCV. The structure of BVDV RdRp has been recently published. It presents several differences relative to HCV RdRp. These differences raise questions about the relevance of BVDV as a surrogate model, and cast novel interest on the "GB" virus C (GBV-C. Indeed, GBV-C is genetically closer to HCV than BVDV, and can lead to productive infection of cultured cells. There is no structural data for the GBV-C RdRp yet. Results We show in this study that the GBV-C RdRp is closest to the HCV RdRp. We report a 3D model of the GBV-C RdRp, developed using sequence-to-structure threading and comparative modeling based on the atomic coordinates of the HCV RdRp structure. Analysis of the predicted structural features in the phylogenetic context of the RNA polymerase family allows rationalizing most of the experimental data available. Both available structures and our model are explored to examine the catalytic cleft, allosteric and substrate binding sites. Conclusion Computational methods were used to infer evolutionary relationships and to predict the structure of a viral RNA polymerase. Docking a GTP molecule into the structure allows defining a GTP binding pocket in the GBV-C RdRp, such as that of BVDV. The resulting model suggests a new proposition for the mechanism of RNA synthesis, and may prove useful to design new experiments to implement our knowledge on the initiation mechanism of RNA

  17. Comparative analysis of epidermal differentiation genes of crocodilians suggests new models for the evolutionary origin of avian feather proteins.

    Science.gov (United States)

    Holthaus, Karin Brigit; Strasser, Bettina; Lachner, Julia; Sukseree, Supawadee; Sipos, Wolfgang; Weissenbacher, Anton; Tschachler, Erwin; Alibardi, Lorenzo; Eckhart, Leopold

    2018-02-12

    The epidermis of amniotes forms a protective barrier against the environment and the differentiation program of keratinocytes, the main cell type in the epidermis, has undergone specific alterations in the course of adaptation of amniotes to a broad variety of environments and lifestyles. The epidermal differentiation complex (EDC) is a cluster of genes expressed at late stages of keratinocyte differentiation in both sauropsids and mammals. In the present study we identified and analyzed the crocodilian equivalent of the EDC. The gene complement of the EDC of both the American alligator and the saltwater crocodile were determined by comparative genomics, de novo gene prediction and identification of EDC transcripts in published transcriptome data. We found that crocodilians have an organization of the EDC similar to that of their closest living relatives, the birds, with which they form the clade Archosauria. Notable differences include the specific expansion of a subfamily of EDC genes in crocodilians and the loss of distinct ancestral EDC genes in birds. Identification and comparative analysis of crocodilian orthologs of avian feather proteins suggest that the latter evolved by cooption and sequence modification of ancestral EDC genes, and that the amplification of an internal highly cysteine-enriched amino acid sequence motif gave rise to the feather component Epidermal Differentiation Cysteine Rich Protein (EDCRP) in the avian lineage. Thus, sequence diversification of EDC genes contributed to the evolutionary divergence of the crocodilian and avian integuments. © The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. Platypus globin genes and flanking loci suggest a new insertional model for beta-globin evolution in birds and mammals

    Directory of Open Access Journals (Sweden)

    Warren Wesley C

    2008-07-01

    Full Text Available Abstract Background Vertebrate alpha (α- and beta (β-globin gene families exemplify the way in which genomes evolve to produce functional complexity. From tandem duplication of a single globin locus, the α- and β-globin clusters expanded, and then were separated onto different chromosomes. The previous finding of a fossil β-globin gene (ω in the marsupial α-cluster, however, suggested that duplication of the α-β cluster onto two chromosomes, followed by lineage-specific gene loss and duplication, produced paralogous α- and β-globin clusters in birds and mammals. Here we analyse genomic data from an egg-laying monotreme mammal, the platypus (Ornithorhynchus anatinus, to explore haemoglobin evolution at the stem of the mammalian radiation. Results The platypus α-globin cluster (chromosome 21 contains embryonic and adult α- globin genes, a β-like ω-globin gene, and the GBY globin gene with homology to cytoglobin, arranged as 5'-ζ-ζ'-αD-α3-α2-α1-ω-GBY-3'. The platypus β-globin cluster (chromosome 2 contains single embryonic and adult globin genes arranged as 5'-ε-β-3'. Surprisingly, all of these globin genes were expressed in some adult tissues. Comparison of flanking sequences revealed that all jawed vertebrate α-globin clusters are flanked by MPG-C16orf35 and LUC7L, whereas all bird and mammal β-globin clusters are embedded in olfactory genes. Thus, the mammalian α- and β-globin clusters are orthologous to the bird α- and β-globin clusters respectively. Conclusion We propose that α- and β-globin clusters evolved from an ancient MPG-C16orf35-α-β-GBY-LUC7L arrangement 410 million years ago. A copy of the original β (represented by ω in marsupials and monotremes was inserted into an array of olfactory genes before the amniote radiation (>315 million years ago, then duplicated and diverged to form orthologous clusters of β-globin genes with different expression profiles in different lineages.

  19. Platypus globin genes and flanking loci suggest a new insertional model for beta-globin evolution in birds and mammals.

    Science.gov (United States)

    Patel, Vidushi S; Cooper, Steven J B; Deakin, Janine E; Fulton, Bob; Graves, Tina; Warren, Wesley C; Wilson, Richard K; Graves, Jennifer A M

    2008-07-25

    Vertebrate alpha (alpha)- and beta (beta)-globin gene families exemplify the way in which genomes evolve to produce functional complexity. From tandem duplication of a single globin locus, the alpha- and beta-globin clusters expanded, and then were separated onto different chromosomes. The previous finding of a fossil beta-globin gene (omega) in the marsupial alpha-cluster, however, suggested that duplication of the alpha-beta cluster onto two chromosomes, followed by lineage-specific gene loss and duplication, produced paralogous alpha- and beta-globin clusters in birds and mammals. Here we analyse genomic data from an egg-laying monotreme mammal, the platypus (Ornithorhynchus anatinus), to explore haemoglobin evolution at the stem of the mammalian radiation. The platypus alpha-globin cluster (chromosome 21) contains embryonic and adult alpha- globin genes, a beta-like omega-globin gene, and the GBY globin gene with homology to cytoglobin, arranged as 5'-zeta-zeta'-alphaD-alpha3-alpha2-alpha1-omega-GBY-3'. The platypus beta-globin cluster (chromosome 2) contains single embryonic and adult globin genes arranged as 5'-epsilon-beta-3'. Surprisingly, all of these globin genes were expressed in some adult tissues. Comparison of flanking sequences revealed that all jawed vertebrate alpha-globin clusters are flanked by MPG-C16orf35 and LUC7L, whereas all bird and mammal beta-globin clusters are embedded in olfactory genes. Thus, the mammalian alpha- and beta-globin clusters are orthologous to the bird alpha- and beta-globin clusters respectively. We propose that alpha- and beta-globin clusters evolved from an ancient MPG-C16orf35-alpha-beta-GBY-LUC7L arrangement 410 million years ago. A copy of the original beta (represented by omega in marsupials and monotremes) was inserted into an array of olfactory genes before the amniote radiation (>315 million years ago), then duplicated and diverged to form orthologous clusters of beta-globin genes with different expression

  20. Modeling thermal dilepton radiation for SIS experiments

    Energy Technology Data Exchange (ETDEWEB)

    Seck, Florian [TU Darmstadt (Germany); Collaboration: HADES-Collaboration

    2016-07-01

    Dileptons are radiated during the whole time evolution of a heavy-ion collision and leave the interaction zone unaffected. Thus they carry valuable information about the hot and dense medium created in those collisions to the detector. Realistic dilepton emission rates and an accurate description of the fireball's space-time evolution are needed to properly describe the contribution of in-medium signals to the dilepton invariant mass spectrum. In this presentation we demonstrate how this can be achieved at SIS collision energies. The framework is implemented into the event generator Pluto which is used by the HADES and CBM experiments to produce their hadronic freeze-out cocktails. With the help of an coarse-graining approach to model the fireball evolution and pertinent dilepton rates via a parametrization of the Rapp-Wambach in-medium ρ meson spectral function, the thermal contribution to the spectrum can be calculated. The results also enable us to get an estimate of the fireball lifetime at SIS18 energies.

  1. Genetic and functional analyses of SHANK2 mutations suggest a multiple hit model of autism spectrum disorders.

    Directory of Open Access Journals (Sweden)

    Claire S Leblond

    2012-02-01

    Full Text Available Autism spectrum disorders (ASD are a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. While many rare variants in synaptic proteins have been identified in patients with ASD, little is known about their effects at the synapse and their interactions with other genetic variations. Here, following the discovery of two de novo SHANK2 deletions by the Autism Genome Project, we identified a novel 421 kb de novo SHANK2 deletion in a patient with autism. We then sequenced SHANK2 in 455 patients with ASD and 431 controls and integrated these results with those reported by Berkel et al. 2010 (n = 396 patients and n = 659 controls. We observed a significant enrichment of variants affecting conserved amino acids in 29 of 851 (3.4% patients and in 16 of 1,090 (1.5% controls (P = 0.004, OR = 2.37, 95% CI = 1.23-4.70. In neuronal cell cultures, the variants identified in patients were associated with a reduced synaptic density at dendrites compared to the variants only detected in controls (P = 0.0013. Interestingly, the three patients with de novo SHANK2 deletions also carried inherited CNVs at 15q11-q13 previously associated with neuropsychiatric disorders. In two cases, the nicotinic receptor CHRNA7 was duplicated and in one case the synaptic translation repressor CYFIP1 was deleted. These results strengthen the role of synaptic gene dysfunction in ASD but also highlight the presence of putative modifier genes, which is in keeping with the "multiple hit model" for ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD.

  2. Expression of venom gene homologs in diverse python tissues suggests a new model for the evolution of snake venom.

    Science.gov (United States)

    Reyes-Velasco, Jacobo; Card, Daren C; Andrew, Audra L; Shaney, Kyle J; Adams, Richard H; Schield, Drew R; Casewell, Nicholas R; Mackessy, Stephen P; Castoe, Todd A

    2015-01-01

    Snake venom gene evolution has been studied intensively over the past several decades, yet most previous studies have lacked the context of complete snake genomes and the full context of gene expression across diverse snake tissues. We took a novel approach to studying snake venom evolution by leveraging the complete genome of the Burmese python, including information from tissue-specific patterns of gene expression. We identified the orthologs of snake venom genes in the python genome, and conducted detailed analysis of gene expression of these venom homologs to identify patterns that differ between snake venom gene families and all other genes. We found that venom gene homologs in the python are expressed in many different tissues outside of oral glands, which illustrates the pitfalls of using transcriptomic data alone to define "venom toxins." We hypothesize that the python may represent an ancestral state prior to major venom development, which is supported by our finding that the expansion of venom gene families is largely restricted to highly venomous caenophidian snakes. Therefore, the python provides insight into biases in which genes were recruited for snake venom systems. Python venom homologs are generally expressed at lower levels, have higher variance among tissues, and are expressed in fewer organs compared with all other python genes. We propose a model for the evolution of snake venoms in which venom genes are recruited preferentially from genes with particular expression profile characteristics, which facilitate a nearly neutral transition toward specialized venom system expression. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Computational Model for Tumor Oxygenation Applied to Clinical Data on Breast Tumor Hemoglobin Concentrations Suggests Vascular Dilatation and Compression.

    Directory of Open Access Journals (Sweden)

    Michael Welter

    Full Text Available We present a computational model for trans-vascular oxygen transport in synthetic tumor and host tissue blood vessel networks, aiming at qualitatively explaining published data of optical mammography, which were obtained from 87 breast cancer patients. The data generally show average hemoglobin concentration to be higher in tumors versus host tissue whereas average oxy-to total hemoglobin concentration (vascular segment RBC-volume-weighted blood oxygenation can be above or below normal. Starting from a synthetic arterio-venous initial network the tumor vasculature was generated by processes involving cooption, angiogenesis, and vessel regression. Calculations of spatially resolved blood flow, hematocrit, oxy- and total hemoglobin concentrations, blood and tissue oxygenation were carried out for ninety tumor and associated normal vessel networks starting from various assumed geometries of feeding arteries and draining veins. Spatial heterogeneity in the extra-vascular partial oxygen pressure distribution can be related to various tumor compartments characterized by varying capillary densities and blood flow characteristics. The reported higher average hemoglobin concentration of tumors is explained by growth and dilatation of tumor blood vessels. Even assuming sixfold metabolic rate of oxygen consumption in tumorous versus host tissue, the predicted oxygen hemoglobin concentrations are above normal. Such tumors are likely associated with high tumor blood flow caused by high-caliber blood vessels crossing the tumor volume and hence oxygen supply exceeding oxygen demand. Tumor oxy- to total hemoglobin concentration below normal could only be achieved by reducing tumor vessel radii during growth by a randomly selected factor, simulating compression caused by intra-tumoral solid stress due to proliferation of cells and extracellular matrix. Since compression of blood vessels will impede chemotherapy we conclude that tumors with oxy- to total

  4. Low Level Evidence Suggests That Librarian-Led Instruction in Evidence Based Practice is Effective Regardless of Instructional Model

    Directory of Open Access Journals (Sweden)

    Lindsay J. Alcock

    2017-06-01

    studies which included descriptive statistics and many also included inferential statistics intended to show significance. Differences between groups were assessed with parametric measures in 9 studies and non-parametric measures in 15 studies. Good to high statistical significance on at least 1 measurement was achieved in 23 studies. Given the absence of effect sizes, the level of differences between study groups could not be determined. Conclusion – Numerous pedagogical methods are used in librarian-led instruction in evidence based practice. However, there is a paucity of high level evidence and the literature suggests that no instructional method is demonstrated to be more effective than another.

  5. Coalescence of liquid drops: Different models versus experiment

    KAUST Repository

    Sprittles, J. E.

    2012-01-01

    The process of coalescence of two identical liquid drops is simulated numerically in the framework of two essentially different mathematical models, and the results are compared with experimental data on the very early stages of the coalescence process reported recently. The first model tested is the "conventional" one, where it is assumed that coalescence as the formation of a single body of fluid occurs by an instant appearance of a liquid bridge smoothly connecting the two drops, and the subsequent process is the evolution of this single body of fluid driven by capillary forces. The second model under investigation considers coalescence as a process where a section of the free surface becomes trapped between the bulk phases as the drops are pressed against each other, and it is the gradual disappearance of this "internal interface" that leads to the formation of a single body of fluid and the conventional model taking over. Using the full numerical solution of the problem in the framework of each of the two models, we show that the recently reported electrical measurements probing the very early stages of the process are better described by the interface formation/disappearance model. New theory-guided experiments are suggested that would help to further elucidate the details of the coalescence phenomenon. As a by-product of our research, the range of validity of different "scaling laws" advanced as approximate solutions to the problem formulated using the conventional model is established. © 2012 American Institute of Physics.

  6. The Context-Dependency of the Experience of Auditory Succession and Prospects for Embodying Philosophical Models of Temporal Experience

    Directory of Open Access Journals (Sweden)

    Maria Kon

    2015-05-01

    Full Text Available Recent philosophical work on temporal experience offers generic models that are often assumed to apply to all sensory modalities. I show that the models serve as broad frameworks in which different aspects of cognitive science can be slotted and, thus, are beneficial to furthering research programs in embodied music cognition. Here I discuss a particular feature of temporal experience that plays a key role in such philosophical work: a distinction between the experience of succession and the mere succession of experiences. I question the presupposition that there is such an evident, clear distinction and suggest that, instead, how the distinction is drawn is context-dependent. After suggesting a way to modify the philosophical models of temporal experience to accommodate this context-dependency, I illustrate that these models can fruitfully incorporate features of research projects in embodied musical cognition. To do so I supplement a modified retentionalist model with aspects of recent work that links bodily movement with musical perception (Godøy, 2006; 2010a; Jensenius, Wanderley, Godøy, and Leman, 2010. The resulting model is shown to facilitate novel hypotheses, refine the notion of context-dependency and point towards means of extending the philosophical model and an existent research program.

  7. Computer models experiences in radiological safety

    International Nuclear Information System (INIS)

    Ferreri, J.C.; Grandi, G.M.; Ventura, M.A.; Doval, A.S.

    1989-01-01

    A review in the formulation and use of numerical methods in fluid dynamics and heat and mass transfer in nuclear safety is presented. A wide range of applications is covered, namely: nuclear reactor's thermohydraulics, natural circulation in closed loops, experiments for the validation of numerical methods, thermohydraulics of fractured-porous media and radionuclide migration. The results of the experience accumulated is a research line dealing at the present with moving grids in computational fluid dynamics and the use of artificial intelligence techniques. As a consequence some recent experience in the development of expert systems and the considerations that should be taken into account for its use in radiological safety is also reviewed. (author)

  8. Model performance evaluation (validation and calibration) in model-based studies of therapeutic interventions for cardiovascular diseases : a review and suggested reporting framework.

    Science.gov (United States)

    Haji Ali Afzali, Hossein; Gray, Jodi; Karnon, Jonathan

    2013-04-01

    Decision analytic models play an increasingly important role in the economic evaluation of health technologies. Given uncertainties around the assumptions used to develop such models, several guidelines have been published to identify and assess 'best practice' in the model development process, including general modelling approach (e.g., time horizon), model structure, input data and model performance evaluation. This paper focuses on model performance evaluation. In the absence of a sufficient level of detail around model performance evaluation, concerns regarding the accuracy of model outputs, and hence the credibility of such models, are frequently raised. Following presentation of its components, a review of the application and reporting of model performance evaluation is presented. Taking cardiovascular disease as an illustrative example, the review investigates the use of face validity, internal validity, external validity, and cross model validity. As a part of the performance evaluation process, model calibration is also discussed and its use in applied studies investigated. The review found that the application and reporting of model performance evaluation across 81 studies of treatment for cardiovascular disease was variable. Cross-model validation was reported in 55 % of the reviewed studies, though the level of detail provided varied considerably. We found that very few studies documented other types of validity, and only 6 % of the reviewed articles reported a calibration process. Considering the above findings, we propose a comprehensive model performance evaluation framework (checklist), informed by a review of best-practice guidelines. This framework provides a basis for more accurate and consistent documentation of model performance evaluation. This will improve the peer review process and the comparability of modelling studies. Recognising the fundamental role of decision analytic models in informing public funding decisions, the proposed

  9. Modelling of the simple pendulum Experiment

    Directory of Open Access Journals (Sweden)

    Palka L.

    2016-01-01

    Full Text Available Abstract - work focuses on the design of the simulation embedded in remote experiment “Simple pendulum” built on the Internet School Experimental System (ISES. This platform is intended for wide educational purposes at schools and universities in order to provide the suitable measuring environment for students using conventional computing resources Informatics.

  10. Some Experiences with Numerical Modelling of Overflows

    DEFF Research Database (Denmark)

    Larsen, Torben; Nielsen, L.; Jensen, B.

    2007-01-01

    across the edge of the overflow. To ensure critical flow across the edge, the upstream flow must be subcritical whereas the downstream flow is either supercritical or a free jet. Experimentally overflows are well studied. Based on laboratory experiments and Froude number scaling, numerous accurate...

  11. Mathematical Modeling: Are Prior Experiences Important?

    Science.gov (United States)

    Czocher, Jennifer A.; Moss, Diana L.

    2017-01-01

    Why are math modeling problems the source of such frustration for students and teachers? The conceptual understanding that students have when engaging with a math modeling problem varies greatly. They need opportunities to make their own assumptions and design the mathematics to fit these assumptions (CCSSI 2010). Making these assumptions is part…

  12. Towards Generic Models of Player Experience

    DEFF Research Database (Denmark)

    Shaker, Noor; Shaker, Mohammad; Abou-Zleikha, Mohamed

    2015-01-01

    Context personalisation is a flourishing area of research with many applications. Context personalisation systems usually employ a user model to predict the appeal of the context to a particular user given a history of interactions. Most of the models used are context...

  13. Design of experiments an introduction based on linear models

    CERN Document Server

    Morris, Max D

    2011-01-01

    IntroductionExample: rainfall and grassland Basic elements of an experimentExperiments and experiment-like studies Models and data analysisLinear Statistical ModelsLinear vector spaces Basic linear model The hat matrix, least-squares estimates, and design information matrixThe partitioned linear model The reduced normal equations Linear and quadratic forms Estimation and information Hypothesis testing and informationBlocking and informationCompletely Randomized DesignsIntroductionModels Matrix formulation Influence of design on estimation Influence of design on hypothesis testingRandomized Com

  14. Evaporation of J13 water: laboratory experiments and geochemical modeling

    International Nuclear Information System (INIS)

    Dibley, M.J.; Knauss, K.G.; Rosenberg, N.D.

    1999-01-01

    We report results from experiments on the evaporative chemical evolution of synthetic J13 water, representative of water from well J13, a common reference water in the Yucca Mountain Project. Data include anion and cation analysis and qualitative mineral identification for a series of open system experiments, with and without crushed tuff present, conducted at sub-boiling temperatures. Ca and Mg precipitated readily as carbonates and anions Cl, F, NO 3 and SO 4 remained in solution in nearly identical ratios. The pH stabilized at about 10. After ∼ 1000x concentration, the minerals formed were amorphous silica, aragonite and calcite. The presence of tuff appears to have very little effect on the relative distribution of the anions in solution, except for possibly F, which had a relatively lower concentration ratio. The Si was lower in the solutions with tuff present suggesting that the tuff enhances SiO 2 precipitation. Even though the tools to model highly-concentrated salt solutions are limited, we compare our experimental results with the results of geochemical models, with (perhaps) surprising good results. In response to different assumed CO 2 levels, pH varied, but anion concentrations were not greatly affected

  15. Modeling the Formation of Language: Embodied Experiments

    Science.gov (United States)

    Steels, Luc

    This chapter gives an overview of different experiments that have been performed to demonstrate how a symbolic communication system, including its underlying ontology, can arise in situated embodied interactions between autonomous agents. It gives some details of the Grounded Naming Game, which focuses on the formation of a system of proper names, the Spatial Language Game, which focuses on the formation of a lexicon for expressing spatial relations as well as perspective reversal, and an Event Description Game, which concerns the expression of the role of participants in events through an emergent case grammar. For each experiment, details are provided how the symbolic system emerges, how the interaction is grounded in the world through the embodiment of the agent and its sensori-motor processing, and how concepts are formed in tight interaction with the emerging language.

  16. Temperature Shift Experiments Suggest That Metabolic Impairment and Enhanced Rates of Photorespiration Decrease Organic Acid Levels in Soybean Leaflets Exposed to Supra-Optimal Growth Temperatures

    Directory of Open Access Journals (Sweden)

    Richard C. Sicher

    2015-08-01

    Full Text Available Elevated growth temperatures are known to affect foliar organic acid concentrations in various plant species. In the current study, citrate, malate, malonate, fumarate and succinate decreased 40 to 80% in soybean leaflets when plants were grown continuously in controlled environment chambers at 36/28 compared to 28/20 °C. Temperature effects on the above mentioned organic acids were partially reversed three days after plants were transferred among optimal and supra-optimal growth temperatures. In addition, CO2 enrichment increased foliar malate, malonate and fumarate concentrations in the supra-optimal temperature treatment, thereby mitigating effects of high temperature on respiratory metabolism. Glycerate, which functions in the photorespiratory pathway, decreased in response to CO2 enrichment at both growth temperatures. The above findings suggested that diminished levels of organic acids in soybean leaflets upon exposure to high growth temperatures were attributable to metabolic impairment and to changes of photorespiratory flux. Leaf development rates differed among temperature and CO2 treatments, which affected foliar organic acid levels. Additionally, we report that large decreases of foliar organic acids in response to elevated growth temperatures were observed in legume species.

  17. A Review of Methodology for Evaluating the Performance of Atmospheric Transport and Dispersion Models and Suggested Protocol for Providing More Informative Results

    Directory of Open Access Journals (Sweden)

    Steven Herring

    2018-03-01

    Full Text Available Many models exist for predicting the atmospheric transport and dispersion of material following its release into the atmosphere. The purpose of these models may be to support air quality assessments and/or to predict the hazard resulting from releases of harmful materials to inform emergency response actions. In either case it is essential that the user understands the level of predictive accuracy that might be expected. However, contrary to expectation, this is not easily determined from published comparisons of model predictions against data from dispersion experiments. The paper presents and reviews the methods adopted and issues involved in comparing the predictive performance of atmospheric transport and dispersion models to experimental data, by reference to a number of experimental data sets and comparison results. It then presents an approach which is designed to make the performance of atmospheric dispersion models more transparent, through clearly defining the basis on which the comparison is made, and comparing the performance of the chosen model to that of a reference model. Such an approach establishes a clear baseline against which the accuracy of models can be evaluated and the performance benefits of more sophisticated approaches quantified. The use of a simple analytic reference model applicable to continuous ground level releases in open terrain and urban areas is shown as a proof-of-principle.

  18. Neutron transport model for standard calculation experiment

    International Nuclear Information System (INIS)

    Lukhminskij, B.E.; Lyutostanskij, Yu.S.; Lyashchuk, V.I.; Panov, I.V.

    1989-01-01

    The neutron transport calculation algorithms in complex composition media with a predetermined geometry are realized by the multigroups representations within Monte Carlo methods in the MAMONT code. The code grade was evaluated with benchmark experiments comparison. The neutron leakage spectra calculations in the spherical-symmetric geometry were carried out for iron and polyethylene. The MAMONT code utilization for metrological furnishes of the geophysics tasks is proposed. The code is orientated towards neutron transport and secondary nuclides accumulation calculations in blankets and geophysics media. 7 refs.; 2 figs

  19. Modeling of modification experiments involving neutral-gas release

    International Nuclear Information System (INIS)

    Bernhardt, P.A.

    1983-01-01

    Many experiments involve the injection of neutral gases into the upper atmosphere. Examples are critical velocity experiments, MHD wave generation, ionospheric hole production, plasma striation formation, and ion tracing. Many of these experiments are discussed in other sessions of the Active Experiments Conference. This paper limits its discussion to: (1) the modeling of the neutral gas dynamics after injection, (2) subsequent formation of ionosphere holes, and (3) use of such holes as experimental tools

  20. Cohesive mixed mode fracture modelling and experiments

    DEFF Research Database (Denmark)

    Walter, Rasmus; Olesen, John Forbes

    2008-01-01

    A nonlinear mixed mode model originally developed by Wernersson [Wernersson H. Fracture characterization of wood adhesive joints. Report TVSM-1006, Lund University, Division of Structural Mechanics; 1994], based on nonlinear fracture mechanics, is discussed and applied to model interfacial cracking....... An experimental set-up for the assessment of mixed mode interfacial fracture properties is presented, applying a bi-material specimen, half steel and half concrete, with an inclined interface and under uniaxial load. Loading the inclined steel–concrete interface under different angles produces load–crack opening...... curves, which may be interpreted using the nonlinear mixed mode model. The interpretation of test results is carried out in a two step inverse analysis applying numerical optimization tools. It is demonstrated how to perform the inverse analysis, which couples the assumed individual experimental load...

  1. Silicon Carbide Derived Carbons: Experiments and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kertesz, Miklos [Georgetown University, Washington DC 20057

    2011-02-28

    The main results of the computational modeling was: 1. Development of a new genealogical algorithm to generate vacancy clusters in diamond starting from monovacancies combined with energy criteria based on TBDFT energetics. The method revealed that for smaller vacancy clusters the energetically optimal shapes are compact but for larger sizes they tend to show graphitized regions. In fact smaller clusters of the size as small as 12 already show signatures of this graphitization. The modeling gives firm basis for the slit-pore modeling of porous carbon materials and explains some of their properties. 2. We discovered small vacancy clusters and their physical characteristics that can be used to spectroscopically identify them. 3. We found low barrier pathways for vacancy migration in diamond-like materials by obtaining for the first time optimized reaction pathways.

  2. Evaporation experiments and modelling for glass melts

    NARCIS (Netherlands)

    Limpt, J.A.C. van; Beerkens, R.G.C.

    2007-01-01

    A laboratory test facility has been developed to measure evaporation rates of different volatile components from commercial and model glass compositions. In the set-up the furnace atmosphere, temperature level, gas velocity and batch composition are controlled. Evaporation rates have been measured

  3. Model of an Evaporating Drop Experiment

    Science.gov (United States)

    Rodriguez, Nicolas

    2017-11-01

    A computational model of an experimental procedure to measure vapor distributions surrounding sessile drops is developed to evaluate the uncertainty in the experimental results. Methanol, which is expected to have predominantly diffusive vapor transport, is chosen as a validation test for our model. The experimental process first uses a Fourier transform infrared spectrometer to measure the absorbance along lines passing through the vapor cloud. Since the measurement contains some errors, our model allows adding random noises to the computational integrated absorbance to mimic this. Then the resulting data are interpolated before passing through a computed tomography routine to generate the vapor distribution. Next, the gradients of the vapor distribution are computed along a given control volume surrounding the drop so that the diffusive flux can be evaluated as the net rate of diffusion out of the control volume. Our model of methanol evaporation shows that the accumulated errors of the whole experimental procedure affect the diffusive fluxes at different control volumes and are sensitive to how the noisy data of integrated absorbance are interpolated. This indicates the importance of investigating a variety of data fitting methods to choose which is best to present the data. Trinity University Mach Fellowship.

  4. Habitat suitability index model for brook trout in streams of the Southern Blue Ridge Province: surrogate variables, model evaluation, and suggested improvements

    Science.gov (United States)

    Christoper J. Schmitt; A. Dennis Lemly; Parley V. Winger

    1993-01-01

    Data from several sources were collated and analyzed by correlation, regression, and principal components analysis to define surrrogate variables for use in the brook trout (Salvelinus fontinalis) habitat suitability index (HSI) model, and to evaluate the applicability of the model for assessing habitat in high elevation streams of the southern Blue Ridge Province (...

  5. Micro- and nanoflows modeling and experiments

    CERN Document Server

    Rudyak, Valery Ya; Maslov, Anatoly A; Minakov, Andrey V; Mironov, Sergey G

    2018-01-01

    This book describes physical, mathematical and experimental methods to model flows in micro- and nanofluidic devices. It takes in consideration flows in channels with a characteristic size between several hundreds of micrometers to several nanometers. Methods based on solving kinetic equations, coupled kinetic-hydrodynamic description, and molecular dynamics method are used. Based on detailed measurements of pressure distributions along the straight and bent microchannels, the hydraulic resistance coefficients are refined. Flows of disperse fluids (including disperse nanofluids) are considered in detail. Results of hydrodynamic modeling of the simplest micromixers are reported. Mixing of fluids in a Y-type and T-type micromixers is considered. The authors present a systematic study of jet flows, jets structure and laminar-turbulent transition. The influence of sound on the microjet structure is considered. New phenomena associated with turbulization and relaminarization of the mixing layer of microjets are di...

  6. Turbulent Boundary Layers - Experiments, Theory and Modelling

    Science.gov (United States)

    1980-01-01

    1979 "Calcul des transferts thermiques entre film chaud et substrat par un modele ä deux dimensions", Int. J. Heat Mass Transfer ^2, p. 111-119...surface heat transfer a to the surface shear Cu/ ; here, corrections are compulsory because the wall shear,stress fluctuations are large (the r.m.s...technique is the mass transfer analogue of the constant temperature anemometer when the chemical reaction at the electrode embedded in the wall is

  7. Previous Experience a Model of Practice UNAE

    OpenAIRE

    Ruiz, Ormary Barberi; Pesántez Palacios, María Dolores

    2017-01-01

    The statements presented in this article represents a preliminary version of the proposed model of pre-professional practices (PPP) of the National University of Education (UNAE) of Ecuador, an urgent institutional necessity is revealed in the descriptive analyzes conducted from technical support - administrative (reports, interviews, testimonials), pedagogical foundations of UNAE (curricular directionality, transverse axes in practice, career plan, approach and diagnostic examination as subj...

  8. Open to Suggestion.

    Science.gov (United States)

    Journal of Reading, 1987

    1987-01-01

    Offers (1) suggestions for improving college students' study skills; (2) a system for keeping track of parent, teacher, and community contacts; (3) suggestions for motivating students using tic tac toe; (4) suggestions for using etymology to improve word retention; (5) a word search grid; and (6) suggestions for using postcards in remedial reading…

  9. Integrated modeling of tokamak experiments with OMFIT

    International Nuclear Information System (INIS)

    Meneghini, Orso; Lao, Lang

    2013-01-01

    One Modeling Framework for Integrated Tasks (OMFIT) is a framework that allows data to be easily exchanged among different codes by providing a unifying data structure. The main idea at the base of OMFIT is to treat files, data and scripts as a uniform collection of objects organized into a tree structure, which provides a consistent way to access and manipulate such collection of heterogeneous objects, independent of their origin. Within the OMFIT tree, data can be copied/referred from one node to another and tasks can call each other allowing for complex compound task to be built. A top-level Graphical User Interface (GUI) allowing users to manage tree objects, carry out simulations and analyze the data either interactively or in batch. OMFIT supports many scientific data formats and when a file is loaded into the framework, its data populates the tree structure, automatically endowing it with many potential uses. Furthermore, seamless integration with experimental management systems allows direct manipulation of their data. In OMFIT modeling tasks are organized into modules, which can be easily combined to create arbitrarily-large multi-physics simulations. Modules inter-dependencies are seamlessly defined by variables referencing tree locations among them. Creation of new modules and customization of existing ones is encouraged by graphical tools for their management and an online repository. High level Application Programmer Interfaces (APIs) enable users to execute their codes on remote servers and creation application-specific GUIs. Finally, within OMFIT it is possible to visualize experimental and modeling data for both quick analysis and publication purposes. Examples of application to the DIII-D tokamak are presented. (author)

  10. Indian Consortia Models: FORSA Libraries' Experiences

    Science.gov (United States)

    Patil, Y. M.; Birdie, C.; Bawdekar, N.; Barve, S.; Anilkumar, N.

    2007-10-01

    With increases in prices of journals, shrinking library budgets and cuts in subscriptions to journals over the years, there has been a big challenge facing Indian library professionals to cope with the proliferation of electronic information resources. There have been sporadic efforts by different groups of libraries in forming consortia at different levels. The types of consortia identified are generally based on various models evolved in India in a variety of forms depending upon the participants' affiliations and funding sources. Indian astronomy library professionals have formed a group called Forum for Resource Sharing in Astronomy and Astrophysics (FORSA), which falls under `Open Consortia', wherein participants are affiliated to different government departments. This is a model where professionals willingly come forward and actively support consortia formation; thereby everyone benefits. As such, FORSA has realized four consortia, viz. Nature Online Consortium; Indian Astrophysics Consortium for physics/astronomy journals of Springer/Kluwer; Consortium for Scientific American Online Archive (EBSCO); and Open Consortium for Lecture Notes in Physics (Springer), which are discussed briefly.

  11. Large scale experiments as a tool for numerical model development

    DEFF Research Database (Denmark)

    Kirkegaard, Jens; Hansen, Erik Asp; Fuchs, Jesper

    2003-01-01

    for improvement of the reliability of physical model results. This paper demonstrates by examples that numerical modelling benefits in various ways from experimental studies (in large and small laboratory facilities). The examples range from very general hydrodynamic descriptions of wave phenomena to specific......Experimental modelling is an important tool for study of hydrodynamic phenomena. The applicability of experiments can be expanded by the use of numerical models and experiments are important for documentation of the validity of numerical tools. In other cases numerical tools can be applied...... hydrodynamic interaction with structures. The examples also show that numerical model development benefits from international co-operation and sharing of high quality results....

  12. Hydrodynamics of Explosion Experiments and Models

    CERN Document Server

    Kedrinskii, Valery K

    2005-01-01

    Hydronamics of Explosion presents the research results for the problems of underwater explosions and contains a detailed analysis of the structure and the parameters of the wave fields generated by explosions of cord and spiral charges, a description of the formation mechanisms for a wide range of cumulative flows at underwater explosions near the free surface, and the relevant mathematical models. Shock-wave transformation in bubbly liquids, shock-wave amplification due to collision and focusing, and the formation of bubble detonation waves in reactive bubbly liquids are studied in detail. Particular emphasis is placed on the investigation of wave processes in cavitating liquids, which incorporates the concepts of the strength of real liquids containing natural microinhomogeneities, the relaxation of tensile stress, and the cavitation fracture of a liquid as the inversion of its two-phase state under impulsive (explosive) loading. The problems are classed among essentially nonlinear processes that occur unde...

  13. "ABC's Earthquake" (Experiments and models in seismology)

    Science.gov (United States)

    Almeida, Ana

    2017-04-01

    Ana Almeida, Portugal Almeida, Ana Escola Básica e Secundária Dr. Vieira de Carvalho Moreira da Maia, Portugal The purpose of this presentation, in poster format, is to disclose an activity which was planned and made by me, in a school on the north of Portugal, using a kit of materials simple and easy to use - the sismo-box. The activity "ABC's Earthquake" was developed under the discipline of Natural Sciences, with students from 7th grade, geosciences teachers and other areas. The possibility of work with the sismo-box was seen as an exciting and promising opportunity to promote science, seismology more specifically, to do science, when using the existing models in the box and with them implement the scientific method, to work and consolidate content and skills in the area of Natural Sciences, to have a time of sharing these materials with classmates, and also with other teachers from the different areas. Throughout the development of the activity, either with students or teachers, it was possible to see the admiration by the models presented in the earthquake-box, as well as, the interest and the enthusiasm in wanting to move and understand what the results after the proposed procedure in the script. With this activity, we managed to promote: - educational success in this subject; a "school culture" with active participation, with quality, rules, discipline and citizenship values; fully integration of students with special educational needs; strengthen the performance of the school as a cultural, informational and formation institution; provide activities to date and innovative; foment knowledge "to be, being and doing" and contribute to a moment of joy and discovery.Learn by doing!

  14. Model building experiences using Garp3: problems, patterns and debugging

    NARCIS (Netherlands)

    Liem, J.; Linnebank, F.E.; Bredeweg, B.; Žabkar, J.; Bratko, I.

    2009-01-01

    Capturing conceptual knowledge in QR models is becoming of interest to a larger audience of domain experts. Consequently, we have been training several groups to effectively create QR models during the last few years. In this paper we describe our teaching experiences, the issues the modellers

  15. Dynamic Rupture Models Suggest High Fluid Pressures and Low Differential Stresses for the M 9.2 2004 Sumatra-Andaman Earthquake

    Science.gov (United States)

    Madden, Elizabeth; van Zelst, Iris; Ulrich, Thomas; van Dinther, Ylona; Gabriel, Alice-Agnes

    2017-04-01

    A major challenge in understanding the physics of megathrust earthquakes is constraining the initial stress field. The close relationship between initial stress and friction and any variations in fault geometry make unique determination of these parameters difficult. In addition, evidence for low effective stresses (e.g. Hardebeck, 2015; Husen and Kissling, 2001) seem incompatible with the occurrence of large megathrust events. Here, we present a series of 3D dynamic ruptures along the plate interface that hosted the 2004 M 9.1-9.3 Sumatra-Andaman earthquake. The dynamic rupture models are performed with SeisSol, which solves for dynamic fault rupture and seismic wave propagation. Use of an unstructured tetrahedral mesh allows for a realistic representation of both the non-planar slab interface and the bathymetry. First, we compare earthquake models under conditions of high versus low fluid pressure. The model with a low fluid pressure (hydrostatic) produces rupture velocities and slip magnitudes that are much too high. The model with a high fluid pressure (near lithostatic) produces the observed average 2.5 km/s rupture speed and slip magnitudes that match the observed GPS surface displacements. This suggests that earthquakes along the Sumatra-Andaman subduction zone operate under the conditions of low effective principal and differential stresses that result from high fluid pressures. For a third model, we use conditions from a 2D seismo-thermo-mechanical earthquake cycle model representing long term deformation at the latitude of the 2004 earthquake's hypocenter. Slip instabilities that approximate earthquakes arise spontaneously along the subduction zone interface in this model. We use the stress and material properties at the time of nucleation for a single earthquake as initial conditions for the dynamic rupture model. In order to produce a reasonable earthquake, fluid pressure must exceed lithostatic near the hypocenter. Because the effective principal

  16. Optimal experiment design for model selection in biochemical networks.

    Science.gov (United States)

    Vanlier, Joep; Tiemann, Christian A; Hilbers, Peter A J; van Riel, Natal A W

    2014-02-20

    Mathematical modeling is often used to formalize hypotheses on how a biochemical network operates by discriminating between competing models. Bayesian model selection offers a way to determine the amount of evidence that data provides to support one model over the other while favoring simple models. In practice, the amount of experimental data is often insufficient to make a clear distinction between competing models. Often one would like to perform a new experiment which would discriminate between competing hypotheses. We developed a novel method to perform Optimal Experiment Design to predict which experiments would most effectively allow model selection. A Bayesian approach is applied to infer model parameter distributions. These distributions are sampled and used to simulate from multivariate predictive densities. The method is based on a k-Nearest Neighbor estimate of the Jensen Shannon divergence between the multivariate predictive densities of competing models. We show that the method successfully uses predictive differences to enable model selection by applying it to several test cases. Because the design criterion is based on predictive distributions, which can be computed for a wide range of model quantities, the approach is very flexible. The method reveals specific combinations of experiments which improve discriminability even in cases where data is scarce. The proposed approach can be used in conjunction with existing Bayesian methodologies where (approximate) posteriors have been determined, making use of relations that exist within the inferred posteriors.

  17. Model and Computing Experiment for Research and Aerosols Usage Management

    Directory of Open Access Journals (Sweden)

    Daler K. Sharipov

    2012-09-01

    Full Text Available The article deals with a math model for research and management of aerosols released into the atmosphere as well as numerical algorithm used as hardware and software systems for conducting computing experiment.

  18. A user experience model for tangible interfaces for children

    NARCIS (Netherlands)

    Reidsma, Dennis; van Dijk, Elisabeth M.A.G.; van der Sluis, Frans; Volpe, G; Camurri, A.; Perloy, L.M.; Nijholt, Antinus

    2015-01-01

    Tangible user interfaces allow children to take advantage of their experience in the real world when interacting with digital information. In this paper we describe a model for tangible user interfaces specifically for children that focuses mainly on the user experience during interaction and on how

  19. Fire Response of Loaded Composite Structures - Experiments and Modeling

    OpenAIRE

    Burdette, Jason A.

    2001-01-01

    In this work, the thermo-mechanical response and failure of loaded, fire-exposed composite structures was studied. Unique experimental equipment and procedures were developed and experiments were performed to assess the effects of mechanical loading and fire exposure on the service life of composite beams. A series of analytical models was assembled to describe the fire growth and structural response processes for the system used in the experiments. This series of models consists of a fire...

  20. Engineering teacher training models and experiences

    Science.gov (United States)

    González-Tirados, R. M.

    2009-04-01

    Education Area, we renewed the programme, content and methodology, teaching the course under the name of "Initial Teacher Training Course within the framework of the European Higher Education Area". Continuous Training means learning throughout one's life as an Engineering teacher. They are actions designed to update and improve teaching staff, and are systematically offered on the current issues of: Teaching Strategies, training for research, training for personal development, classroom innovations, etc. They are activities aimed at conceptual change, changing the way of teaching and bringing teaching staff up-to-date. At the same time, the Institution is at the disposal of all teaching staff as a meeting point to discuss issues in common, attend conferences, department meetings, etc. In this Congress we present a justification of both training models and their design together with some results obtained on: training needs, participation, how it is developing and to what extent students are profiting from it.

  1. Structural models of zebrafish (Danio rerio NOD1 and NOD2 NACHT domains suggest differential ATP binding orientations: insights from computational modeling, docking and molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Jitendra Maharana

    Full Text Available Nucleotide-binding oligomerization domain-containing protein 1 (NOD1 and NOD2 are cytosolic pattern recognition receptors playing pivotal roles in innate immune signaling. NOD1 and NOD2 recognize bacterial peptidoglycan derivatives iE-DAP and MDP, respectively and undergoes conformational alternation and ATP-dependent self-oligomerization of NACHT domain followed by downstream signaling. Lack of structural adequacy of NACHT domain confines our understanding about the NOD-mediated signaling mechanism. Here, we predicted the structure of NACHT domain of both NOD1 and NOD2 from model organism zebrafish (Danio rerio using computational methods. Our study highlighted the differential ATP binding modes in NOD1 and NOD2. In NOD1, γ-phosphate of ATP faced toward the central nucleotide binding cavity like NLRC4, whereas in NOD2 the cavity was occupied by adenine moiety. The conserved 'Lysine' at Walker A formed hydrogen bonds (H-bonds and Aspartic acid (Walker B formed electrostatic interaction with ATP. At Sensor 1, Arg328 of NOD1 exhibited an H-bond with ATP, whereas corresponding Arg404 of NOD2 did not. 'Proline' of GxP motif (Pro386 of NOD1 and Pro464 of NOD2 interacted with adenine moiety and His511 at Sensor 2 of NOD1 interacted with γ-phosphate group of ATP. In contrast, His579 of NOD2 interacted with the adenine moiety having a relatively inverted orientation. Our findings are well supplemented with the molecular interaction of ATP with NLRC4, and consistent with mutagenesis data reported for human, which indicates evolutionary shared NOD signaling mechanism. Together, this study provides novel insights into ATP binding mechanism, and highlights the differential ATP binding modes in zebrafish NOD1 and NOD2.

  2. Spectral evaluation of Earth geopotential models and an experiment ...

    Indian Academy of Sciences (India)

    and an experiment on its regional improvement for geoid modelling. B Erol. Department of Geomatics Engineering, Civil Engineering Faculty,. Istanbul Technical University, Maslak 34469, Istanbul, Turkey. e-mail: bihter@itu.edu.tr. As the number of Earth geopotential models (EGM) grows with the increasing number of data ...

  3. Historical and idealized climate model experiments: an EMIC intercomparison

    DEFF Research Database (Denmark)

    Eby, M.; Weaver, A. J.; Alexander, K.

    2012-01-01

    Both historical and idealized climate model experiments are performed with a variety of Earth System Models of Intermediate Complexity (EMICs) as part of a community contribution to the Intergovernmental Panel on Climate Change Fifth Assessment Report. Historical simulations start at 850 CE and c...

  4. Model experiments related to outdoor propagation over an earth berm

    DEFF Research Database (Denmark)

    Rasmussen, Karsten Bo

    1994-01-01

    A series of scale model experiments related to outdoor propagation over an earth berm is described. The measurements are performed with a triggered spark source. The results are compared with data from an existing calculation model based upon uniform diffraction theory. Comparisons are made...

  5. Teaching Structures with Models : Experiences from Chile and the Netherlands

    NARCIS (Netherlands)

    Morales Beltran, M.G.; Borgart, A.

    2012-01-01

    This paper states the importance of using scaled models for the teaching of structures in the curricula of Architecture and Structural Engineering studies. Based on 10 years’ experience working with models for different purposes, with a variety of materials and constructions methods, the authors

  6. Human strategic reasoning in dynamic games: Experiments, logics, cognitive models

    NARCIS (Netherlands)

    Ghosh, Sujata; Halder, Tamoghna; Sharma, Khyati; Verbrugge, Rineke

    2015-01-01

    © Springer-Verlag Berlin Heidelberg 2015.This article provides a three-way interaction between experiments, logic and cognitive modelling so as to bring out a shared perspective among these diverse areas, aiming towards better understanding and better modelling of human strategic reasoning in

  7. High mortality of blue, humpback and fin whales from modeling of vessel collisions on the U.S. West Coast suggests population impacts and insufficient protection.

    Directory of Open Access Journals (Sweden)

    R Cotton Rockwood

    Full Text Available Mortality from collisions with vessels is one of the main human causes of death for large whales. Ship strikes are rarely witnessed and the distribution of strike risk and estimates of mortality remain uncertain at best. We estimated ship strike mortality for blue humpback and fin whales in U.S. West Coast waters using a novel application of a naval encounter model. Mortality estimates from the model were far higher than current minimum estimates derived from stranding records and are closer to extrapolations adjusted for detection probabilities of dead whales. Our most conservative model estimated mortality to be 7.8x, 2.0x and 2.7x the U.S. recommended limit for blue, humpback and fin whales, respectively, suggesting that death from vessel collisions may be a significant impediment to population growth and recovery. Comparing across the study area, the majority of strike mortality occurs in waters off California, from Bodega Bay south and tends to be concentrated in a band approximately 24 Nm (44.5 km offshore and in designated shipping lanes leading to and from major ports. While some mortality risk exists across nearly all West Coast waters, 74%, 82% and 65% of blue, humpback and fin whale mortality, respectively, occurs in just 10% of the study area, suggesting conservation efforts can be very effective if focused in these waters. Risk is highest in the shipping lanes off San Francisco and Long Beach, but only a fraction of total estimated mortality occurs in these proportionally small areas, making any conservation efforts exclusively within these areas insufficient to address overall strike mortality. We recommend combining shipping lane modifications and re-locations, ship speed reductions and creation of 'Areas to be Avoided' by vessels in ecologically important locations to address this significant source of whale mortality.

  8. High mortality of blue, humpback and fin whales from modeling of vessel collisions on the U.S. West Coast suggests population impacts and insufficient protection.

    Science.gov (United States)

    Rockwood, R Cotton; Calambokidis, John; Jahncke, Jaime

    2017-01-01

    Mortality from collisions with vessels is one of the main human causes of death for large whales. Ship strikes are rarely witnessed and the distribution of strike risk and estimates of mortality remain uncertain at best. We estimated ship strike mortality for blue humpback and fin whales in U.S. West Coast waters using a novel application of a naval encounter model. Mortality estimates from the model were far higher than current minimum estimates derived from stranding records and are closer to extrapolations adjusted for detection probabilities of dead whales. Our most conservative model estimated mortality to be 7.8x, 2.0x and 2.7x the U.S. recommended limit for blue, humpback and fin whales, respectively, suggesting that death from vessel collisions may be a significant impediment to population growth and recovery. Comparing across the study area, the majority of strike mortality occurs in waters off California, from Bodega Bay south and tends to be concentrated in a band approximately 24 Nm (44.5 km) offshore and in designated shipping lanes leading to and from major ports. While some mortality risk exists across nearly all West Coast waters, 74%, 82% and 65% of blue, humpback and fin whale mortality, respectively, occurs in just 10% of the study area, suggesting conservation efforts can be very effective if focused in these waters. Risk is highest in the shipping lanes off San Francisco and Long Beach, but only a fraction of total estimated mortality occurs in these proportionally small areas, making any conservation efforts exclusively within these areas insufficient to address overall strike mortality. We recommend combining shipping lane modifications and re-locations, ship speed reductions and creation of 'Areas to be Avoided' by vessels in ecologically important locations to address this significant source of whale mortality.

  9. Expertly validated models and phylogenetically-controlled analysis suggests responses to climate change are related to species traits in the order lagomorpha.

    Directory of Open Access Journals (Sweden)

    Katie Leach

    Full Text Available Climate change during the past five decades has impacted significantly on natural ecosystems, and the rate of current climate change is of great concern among conservation biologists. Species Distribution Models (SDMs have been used widely to project changes in species' bioclimatic envelopes under future climate scenarios. Here, we aimed to advance this technique by assessing future changes in the bioclimatic envelopes of an entire mammalian order, the Lagomorpha, using a novel framework for model validation based jointly on subjective expert evaluation and objective model evaluation statistics. SDMs were built using climatic, topographical, and habitat variables for all 87 lagomorph species under past and current climate scenarios. Expert evaluation and Kappa values were used to validate past and current models and only those deemed 'modellable' within our framework were projected under future climate scenarios (58 species. Phylogenetically-controlled regressions were used to test whether species traits correlated with predicted responses to climate change. Climate change is likely to impact more than two-thirds of lagomorph species, with leporids (rabbits, hares, and jackrabbits likely to undertake poleward shifts with little overall change in range extent, whilst pikas are likely to show extreme shifts to higher altitudes associated with marked range declines, including the likely extinction of Kozlov's Pika (Ochotona koslowi. Smaller-bodied species were more likely to exhibit range contractions and elevational increases, but showing little poleward movement, and fecund species were more likely to shift latitudinally and elevationally. Our results suggest that species traits may be important indicators of future climate change and we believe multi-species approaches, as demonstrated here, are likely to lead to more effective mitigation measures and conservation management. We strongly advocate studies minimising data gaps in our knowledge of

  10. Disentangling unisensory from fusion effects in the attentional modulation of McGurk effects: a Bayesian modeling study suggests that fusion is attention-dependent

    DEFF Research Database (Denmark)

    Schwartz, Jean-Luc; Tiiippana, Kaisa; Andersen, Tobias

    2010-01-01

    The McGurk effect has been shown to be modulated by attention. However, it remains unclear whether attentional effects are due to changes in unisensory processing or in the fusion mechanism. In this paper, we used published experimental data showing that distraction of visual attention weakens th...... Selection criterion. Our findings suggest that distraction of visual attention affects fusion by decreasing the weight of the visual input.......The McGurk effect has been shown to be modulated by attention. However, it remains unclear whether attentional effects are due to changes in unisensory processing or in the fusion mechanism. In this paper, we used published experimental data showing that distraction of visual attention weakens...... the McGurk effect, to fit either the Fuzzy Logical Model of Perception (FLMP) in which the fusion mechanism is fixed, or a variant of it in which the fusion mechanism could be varied depending on attention. The latter model was associated with a larger likelihood when assessed with a Bayesian Model...

  11. Applying the Job Characteristics Model to the College Education Experience

    Science.gov (United States)

    Kass, Steven J.; Vodanovich, Stephen J.; Khosravi, Jasmine Y.

    2011-01-01

    Boredom is one of the most common complaints among university students, with studies suggesting its link to poor grades, drop out, and behavioral problems. Principles borrowed from industrial-organizational psychology may help prevent boredom and enrich the classroom experience. In the current study, we applied the core dimensions of the job…

  12. Simulated Models Suggest That Price per Calorie Is the Dominant Price Metric That Low-Income Individuals Use for Food Decision Making.

    Science.gov (United States)

    Beheshti, Rahmatollah; Igusa, Takeru; Jones-Smith, Jessica

    2016-11-01

    The price of food has long been considered one of the major factors that affects food choices. However, the price metric (e.g., the price of food per calorie or the price of food per gram) that individuals predominantly use when making food choices is unclear. Understanding which price metric is used is especially important for studying individuals with severe budget constraints because food price then becomes even more important in food choice. We assessed which price metric is used by low-income individuals in deciding what to eat. With the use of data from NHANES and the USDA Food and Nutrient Database for Dietary Studies, we created an agent-based model that simulated an environment representing the US population, wherein individuals were modeled as agents with a specific weight, age, and income. In our model, agents made dietary food choices while meeting their budget limits with the use of 1 of 3 different metrics for decision making: energy cost (price per calorie), unit price (price per gram), and serving price (price per serving). The food consumption patterns generated by our model were compared to 3 independent data sets. The food choice behaviors observed in 2 of the data sets were found to be closest to the simulated dietary patterns generated by the price per calorie metric. The behaviors observed in the third data set were equidistant from the patterns generated by price per calorie and price per serving metrics, whereas results generated by the price per gram metric were further away. Our simulations suggest that dietary food choice based on price per calorie best matches actual consumption patterns and may therefore be the most salient price metric for low-income populations. © 2016 American Society for Nutrition.

  13. Cognitive Modeling of Video Game Player User Experience

    Science.gov (United States)

    Bohil, Corey J.; Biocca, Frank A.

    2010-01-01

    This paper argues for the use of cognitive modeling to gain a detailed and dynamic look into user experience during game play. Applying cognitive models to game play data can help researchers understand a player's attentional focus, memory status, learning state, and decision strategies (among other things) as these cognitive processes occurred throughout game play. This is a stark contrast to the common approach of trying to assess the long-term impact of games on cognitive functioning after game play has ended. We describe what cognitive models are, what they can be used for and how game researchers could benefit by adopting these methods. We also provide details of a single model - based on decision field theory - that has been successfUlly applied to data sets from memory, perception, and decision making experiments, and has recently found application in real world scenarios. We examine possibilities for applying this model to game-play data.

  14. Mnemonic Discrimination Deficits in First-Episode Psychosis and a Ketamine Model Suggests Dentate Gyrus Pathology Linked to N-Methyl-D-Aspartate Receptor Hypofunction.

    Science.gov (United States)

    Kraguljac, Nina Vanessa; Carle, Matthew; Frölich, Michael A; Tran, Steve; Yassa, Michael A; White, David Matthew; Reddy, Abhishek; Lahti, Adrienne Carol

    2018-03-01

    Converging evidence from neuroimaging and postmortem studies suggests that hippocampal subfields are differentially affected in schizophrenia. Recent studies report dentate gyrus dysfunction in chronic schizophrenia, but the underlying mechanisms remain to be elucidated. Here we sought to examine if this deficit is already present in first-episode psychosis, and if N-methyl-D-aspartate receptor hypofunction, a putative central pathophysiological mechanism in schizophrenia, experimentally induced by ketamine, would result in a similar abnormality. We applied a mnemonic discrimination task selectively taxing pattern separation in two experiments: 1) a group of 23 first-episode psychosis patients and 23 matched healthy volunteers and 2) a group of 19 healthy volunteers before and during a ketamine challenge (0.27 mg/kg over 10 minutes, then 0.25 mg/kg/hour for 50 minutes, 0.01 mL/s). We calculated response bias-corrected pattern separation and recognition scores. We also examined the relationships between task performance and symptom severity as well as ketamine levels. We report a deficit in pattern separation but not recognition performance in first-episode psychosis patients compared with healthy volunteers (p = .04) and in volunteers during the ketamine challenge compared with baseline (p = .003). Exploratory analyses revealed no correlation between task performance and Repeatable Battery for the Assessment of Neuropsychological Status total scores or positive symptoms in first-episode psychosis patients, or with ketamine serum levels. We observed a mnemonic discrimination deficit but intact recognition in both datasets. Our findings suggest a tentative mechanistic link between dentate gyrus dysfunction in first-episode psychosis and N-methyl-D-aspartate receptor hypofunction. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  15. SSC superconducting dipole magnet cryostat model style B construction experience

    International Nuclear Information System (INIS)

    Engler, N.H.; Bossert, R.C.; Carson, J.A.; Gonczy, J.D.; Larson, E.T.; Nicol, T.H.; Niemann, R.C.; Sorensen, D.; Zink, R.

    1989-03-01

    A program to upgrade the full scale SSC dipole magnet cryostat model function and assembly methods has resulted in a series of dipole magnets designated as style B construction. New design features and assembly techniques have produced a magnet and cryostat assembly that is the basis for Phase 1 of the SSC dipole magnet industrialization program. Details of the assembly program, assembly experience, and comparison to previous assembly experiences are presented. Improvements in magnet assembly techniques are also evaluated. 6 refs., 5 figs

  16. Deepening sleep by hypnotic suggestion.

    Science.gov (United States)

    Cordi, Maren J; Schlarb, Angelika A; Rasch, Björn

    2014-06-01

    Slow wave sleep (SWS) plays a critical role in body restoration and promotes brain plasticity; however, it markedly declines across the lifespan. Despite its importance, effective tools to increase SWS are rare. Here we tested whether a hypnotic suggestion to "sleep deeper" extends the amount of SWS. Within-subject, placebo-controlled crossover design. Sleep laboratory at the University of Zurich, Switzerland. Seventy healthy females 23.27 ± 3.17 y. Participants listened to an auditory text with hypnotic suggestions or a control tape before napping for 90 min while high-density electroencephalography was recorded. After participants listened to the hypnotic suggestion to "sleep deeper" subsequent SWS was increased by 81% and time spent awake was reduced by 67% (with the amount of SWS or wake in the control condition set to 100%). Other sleep stages remained unaffected. Additionally, slow wave activity was significantly enhanced after hypnotic suggestions. During the hypnotic tape, parietal theta power increases predicted the hypnosis-induced extension of SWS. Additional experiments confirmed that the beneficial effect of hypnotic suggestions on SWS was specific to the hypnotic suggestion and did not occur in low suggestible participants. Our results demonstrate the effectiveness of hypnotic suggestions to specifically increase the amount and duration of slow wave sleep (SWS) in a midday nap using objective measures of sleep in young, healthy, suggestible females. Hypnotic suggestions might be a successful tool with a lower risk of adverse side effects than pharmacological treatments to extend SWS also in clinical and elderly populations.

  17. An Evaluation of the FLAG Friction Model frictmultiscale2 using the Experiments of Juanicotena and Szarynski

    Energy Technology Data Exchange (ETDEWEB)

    Zocher, Marvin Anthony [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hammerberg, James Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-15

    The experiments of Juanicotena and Szarynski, namely T101, T102, and T105 are modeled for purposes of gaining a better understanding of the FLAG friction model frictmultiscale2. This exercise has been conducted as a first step toward model validation. It is shown that with inclusion of the friction model in the numerical analysis, the results of Juanicotena and Szarynski are predicted reasonably well. Without the friction model, simulation results do not match the experimental data nearly as well. Suggestions for follow-on work are included.

  18. Modeling a ponded infiltration experiment at Yucca Mountain, NV

    International Nuclear Information System (INIS)

    Hudson, D.B.; Guertal, W.R.; Flint, A.L.

    1994-01-01

    Yucca Mountain, Nevada is being evaluated as a potential site for a geologic repository for high level radioactive waste. As part of the site characterization activities at Yucca Mountain, a field-scale ponded infiltration experiment was done to help characterize the hydraulic and infiltration properties of a layered dessert alluvium deposit. Calcium carbonate accumulation and cementation, heterogeneous layered profiles, high evapotranspiration, low precipitation, and rocky soil make the surface difficult to characterize.The effects of the strong morphological horizonation on the infiltration processes, the suitability of measured hydraulic properties, and the usefulness of ponded infiltration experiments in site characterization work were of interest. One-dimensional and two-dimensional radial flow numerical models were used to help interpret the results of the ponding experiment. The objective of this study was to evaluate the results of a ponded infiltration experiment done around borehole UE25 UZN number-sign 85 (N85) at Yucca Mountain, NV. The effects of morphological horizons on the infiltration processes, lateral flow, and measured soil hydaulic properties were studied. The evaluation was done by numerically modeling the results of a field ponded infiltration experiment. A comparison the experimental results and the modeled results was used to qualitatively indicate the degree to which infiltration processes and the hydaulic properties are understood. Results of the field characterization, soil characterization, borehole geophysics, and the ponding experiment are presented in a companion paper

  19. Neutral null models for diversity in serial transfer evolution experiments.

    Science.gov (United States)

    Harpak, Arbel; Sella, Guy

    2014-09-01

    Evolution experiments with microorganisms coupled with genome-wide sequencing now allow for the systematic study of population genetic processes under a wide range of conditions. In learning about these processes in natural, sexual populations, neutral models that describe the behavior of diversity and divergence summaries have played a pivotal role. It is therefore natural to ask whether neutral models, suitably modified, could be useful in the context of evolution experiments. Here, we introduce coalescent models for polymorphism and divergence under the most common experimental evolution assay, a serial transfer experiment. This relatively simple setting allows us to address several issues that could affect diversity patterns in evolution experiments, whether selection is operating or not: the transient behavior of neutral polymorphism in an experiment beginning from a single clone, the effects of randomness in the timing of cell division and noisiness in population size in the dilution stage. In our analyses and discussion, we emphasize the implications for experiments aimed at measuring diversity patterns and making inferences about population genetic processes based on these measurements. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  20. Detecting physics beyond the Standard Model with the REDTOP experiment

    Science.gov (United States)

    González, D.; León, D.; Fabela, B.; Pedraza, M. I.

    2017-10-01

    REDTOP is an experiment at its proposal stage. It belongs to the High Intensity class of experiments. REDTOP will use a 1.8 GeV continuous proton beam impinging on a fixed target. It is expected to produce about 1013 η mesons per year. The main goal of REDTOP is to look for physics beyond the Standard Model by detecting rare η decays. The detector is designed with innovative technologies based on the detection of prompt Cherenkov light, such that interesting events can be observed and the background events are efficiently rejected. The experimental design, the physics program and the running plan of the experiment is presented.

  1. Electrical conductivity of old oceanic mantle in the northwestern Pacific I: 1-D profiles suggesting differences in thermal structure not predictable from a plate cooling model

    Science.gov (United States)

    Baba, Kiyoshi; Tada, Noriko; Matsuno, Tetsuo; Liang, Pengfei; Li, Ruibai; Zhang, Luolei; Shimizu, Hisayoshi; Abe, Natsue; Hirano, Naoto; Ichiki, Masahiro; Utada, Hisashi

    2017-08-01

    Seafloor magnetotelluric (MT) experiments were recently conducted in two areas of the northwestern Pacific to investigate the nature of the old oceanic upper mantle. The areas are far from any tectonic activity, and "normal" mantle structure is therefore expected. The data were carefully analyzed to reduce the effects of coastlines and seafloor topographic changes, which are significant boundaries in electrical conductivity and thus distort seafloor MT data. An isotropic, one-dimensional electrical conductivity profile was estimated for each area. The profiles were compared with those obtained from two previous study areas in the northwestern Pacific. Between the four profiles, significant differences were observed in the thickness of the resistive layer beyond expectations based on cooling of homogeneous oceanic lithosphere over time. This surprising feature is now further clarified from what was suggested in a previous study. To explain the observed spatial variation, dynamic processes must be introduced, such as influence of the plume associated with the formation of the Shatsky Rise, or spatially non-uniform, small-scale convection in the asthenosphere. There is significant room of further investigation to determine a reasonable and comprehensive interpretation of the lithosphere-asthenosphere system beneath the northwestern Pacific. The present results demonstrate that electrical conductivity provides key information for such investigation.[Figure not available: see fulltext.

  2. A Physical Model Suggests That Hip-Localized Balance Sense in Birds Improves State Estimation in Perching: Implications for Bipedal Robots

    Directory of Open Access Journals (Sweden)

    Darío Urbina-Meléndez

    2018-04-01

    Full Text Available In addition to a vestibular system, birds uniquely have a balance-sensing organ within the pelvis, called the lumbosacral organ (LSO. The LSO is well developed in terrestrial birds, possibly to facilitate balance control in perching and terrestrial locomotion. No previous studies have quantified the functional benefits of the LSO for balance. We suggest two main benefits of hip-localized balance sense: reduced sensorimotor delay and improved estimation of foot-ground acceleration. We used system identification to test the hypothesis that hip-localized balance sense improves estimates of foot acceleration compared to a head-localized sense, due to closer proximity to the feet. We built a physical model of a standing guinea fowl perched on a platform, and used 3D accelerometers at the hip and head to replicate balance sense by the LSO and vestibular systems. The horizontal platform was attached to the end effector of a 6 DOF robotic arm, allowing us to apply perturbations to the platform analogous to motions of a compliant branch. We also compared state estimation between models with low and high neck stiffness. Cross-correlations revealed that foot-to-hip sensing delays were shorter than foot-to-head, as expected. We used multi-variable output error state-space (MOESP system identification to estimate foot-ground acceleration as a function of hip- and head-localized sensing, individually and combined. Hip-localized sensors alone provided the best state estimates, which were not improved when fused with head-localized sensors. However, estimates from head-localized sensors improved with higher neck stiffness. Our findings support the hypothesis that hip-localized balance sense improves the speed and accuracy of foot state estimation compared to head-localized sense. The findings also suggest a role of neck muscles for active sensing for balance control: increased neck stiffness through muscle co-contraction can improve the utility of vestibular

  3. Mixed modeling of meta-analysis P-values (MixMAP suggests multiple novel gene loci for low density lipoprotein cholesterol.

    Directory of Open Access Journals (Sweden)

    Andrea S Foulkes

    Full Text Available Informing missing heritability for complex disease will likely require leveraging information across multiple SNPs within a gene region simultaneously to characterize gene and locus-level contributions to disease phenotypes. To this aim, we introduce a novel strategy, termed Mixed modeling of Meta-Analysis P-values (MixMAP, that draws on a principled statistical modeling framework and the vast array of summary data now available from genetic association studies, to test formally for locus level association. The primary inputs to this approach are: (a single SNP level p-values for tests of association; and (b the mapping of SNPs to genomic regions. The output of MixMAP is comprised of locus level estimates and tests of association. In application of MixMAP to summary data from the Global Lipids Gene Consortium, we suggest twelve new loci (PKN, FN1, UGT1A1, PPARG, DMDGH, PPARD, CDK6, VPS13B, GAD2, GAB2, APOH and NPC1 for low-density lipoprotein cholesterol (LDL-C, a causal risk factor for cardiovascular disease and we also demonstrate the potential utility of MixMAP in small data settings. Overall, MixMAP offers novel and complementary information as compared to SNP-based analysis approaches and is straightforward to implement with existing open-source statistical software tools.

  4. SME International Business Models: The Role of Context and Experience

    DEFF Research Database (Denmark)

    Child, John; Hsieh, Linda; Elbanna, Said

    2017-01-01

    This paper addresses two questions through a study of 180 SMEs located in contrasting industry and home country contexts. First, which business models for international markets prevail among SMEs and do they configure into different types? Second, which factors predict the international business...... models that SMEs follow? Three distinct international business models (traditional market-adaptive, technology exploiter, and ambidextrous explorer) are found among the SMEs studied. The likelihood of SMEs adopting one business model rather than another is to a high degree predictable with reference...... to a small set of factors: industry, level of home economy development, and decision-maker international experience....

  5. Modeling a set of heavy oil aqueous pyrolysis experiments

    Energy Technology Data Exchange (ETDEWEB)

    Thorsness, C.B.; Reynolds, J.G.

    1996-11-01

    Aqueous pyrolysis experiments, aimed at mild upgrading of heavy oil, were analyzed using various computer models. The primary focus of the analysis was the pressure history of the closed autoclave reactors obtained during the heating of the autoclave to desired reaction temperatures. The models used included a means of estimating nonideal behavior of primary components with regard to vapor liquid equilibrium. The modeling indicated that to match measured autoclave pressures, which often were well below the vapor pressure of water at a given temperature, it was necessary to incorporate water solubility in the oil phase and an activity model for the water in the oil phase which reduced its fugacity below that of pure water. Analysis also indicated that the mild to moderate upgrading of the oil which occurred in experiments that reached 400{degrees}C or more using a FE(III) 2-ethylhexanoate could be reasonably well characterized by a simple first order rate constant of 1.7xl0{sup 8} exp(-20000/T)s{sup {minus}l}. Both gas production and API gravity increase were characterized by this rate constant. Models were able to match the complete pressure history of the autoclave experiments fairly well with relatively simple equilibria models. However, a consistent lower than measured buildup in pressure at peak temperatures was noted in the model calculations. This phenomena was tentatively attributed to an increase in the amount of water entering the vapor phase caused by a change in its activity in the oil phase.

  6. Numerical modeling of the 2017 active seismic infrasound balloon experiment

    Science.gov (United States)

    Brissaud, Q.; Komjathy, A.; Garcia, R.; Cutts, J. A.; Pauken, M.; Krishnamoorthy, S.; Mimoun, D.; Jackson, J. M.; Lai, V. H.; Kedar, S.; Levillain, E.

    2017-12-01

    We have developed a numerical tool to propagate acoustic and gravity waves in a coupled solid-fluid medium with topography. It is a hybrid method between a continuous Galerkin and a discontinuous Galerkin method that accounts for non-linear atmospheric waves, visco-elastic waves and topography. We apply this method to a recent experiment that took place in the Nevada desert to study acoustic waves from seismic events. This experiment, developed by JPL and its partners, wants to demonstrate the viability of a new approach to probe seismic-induced acoustic waves from a balloon platform. To the best of our knowledge, this could be the only way, for planetary missions, to perform tomography when one faces challenging surface conditions, with high pressure and temperature (e.g. Venus), and thus when it is impossible to use conventional electronics routinely employed on Earth. To fully demonstrate the effectiveness of such a technique one should also be able to reconstruct the observed signals from numerical modeling. To model the seismic hammer experiment and the subsequent acoustic wave propagation, we rely on a subsurface seismic model constructed from the seismometers measurements during the 2017 Nevada experiment and an atmospheric model built from meteorological data. The source is considered as a Gaussian point source located at the surface. Comparison between the numerical modeling and the experimental data could help future mission designs and provide great insights into the planet's interior structure.

  7. Transport and metabolic degradation of hydrogen peroxide in Chara corallina: model calculations and measurements with the pressure probe suggest transport of H(2)O(2) across water channels.

    Science.gov (United States)

    Henzler, T; Steudle, E

    2000-12-01

    A mathematical model is presented that describes permeation of hydrogen peroxide across a cell membrane and the implications of solute decomposition by catalase inside the cell. The model was checked and analysed by means of a numerical calculation that raised predictions for measured osmotic pressure relaxation curves. Predictions were tested with isolated internodal cells of CHARA: corallina, a model system for investigating interactions between water and solute transport in plant cells. Series of biphasic osmotic pressure relaxation curves with different concentrations of H(2)O(2) of up to 350 mol m(-3) are presented. A detailed description of determination of permeability (P(s)) and reflection coefficients (sigma(s)) for H(2)O(2) is given in the presence of the chemical reaction in the cell. Mean values were P(s)=(3.6+/-1.0) 10(-6) m s(-1) and sigma(s)=(0.33+/-0.12) (+/-SD, N=6 cells). Besides transport properties, coefficients for the catalase reaction following a Michaelis-Menten type of kinetics were determined. Mean values of the Michaelis constant (k(M)) and the maximum rate of decompositon (v(max)) were k(M)=(85+/-55) mol m(-3) and v(max)=(49+/-40) nmol (s cell)(-1), respectively. The absolute values of P:(s) and sigma(s) of H(2)O(2) indicated that hydrogen peroxide, a molecule with chemical properties close to that of water, uses water channels (aquaporins) to cross the cell membrane rapidly. When water channels were inhibited with the blocker mercuric chloride (HgCl(2)), the permeabilities of both water and H(2)O(2) were substantially reduced. In fact, for the latter, it was not measurable. It is suggested that some of the water channels in CHARA: (and, perhaps, in other species) serve as 'peroxoporins' rather than as 'aquaporins'.

  8. A spatially explicit metapopulation model and cattle trade analysis suggests key determinants for the recurrent circulation of rift valley Fever virus in a pilot area of madagascar highlands.

    Science.gov (United States)

    Nicolas, Gaëlle; Chevalier, Véronique; Tantely, Luciano Michaël; Fontenille, Didier; Durand, Benoît

    2014-12-01

    Rift Valley fever (RVF) is a vector-borne zoonotic disease that causes high morbidity and mortality in ruminants. In 2008-2009, a RVF outbreak affected the whole Madagascar island, including the Anjozorobe district located in Madagascar highlands. An entomological survey showed the absence of Aedes among the potential RVF virus (RVFV) vector species identified in this area, and an overall low abundance of mosquitoes due to unfavorable climatic conditions during winter. No serological nor virological sign of infection was observed in wild terrestrial mammals of the area, suggesting an absence of wild RVF virus (RVFV) reservoir. However, a three years serological and virological follow-up in cattle showed a recurrent RVFV circulation. The objective of this study was to understand the key determinants of this unexpected recurrent transmission. To achieve this goal, a spatial deterministic discrete-time metapopulation model combined with cattle trade network was designed and parameterized to reproduce the local conditions using observational data collected in the area. Three scenarios that could explain the RVFV recurrent circulation in the area were analyzed: (i) RVFV overwintering thanks to a direct transmission between cattle when viraemic cows calve, vectors being absent during the winter, (ii) a low level vector-based circulation during winter thanks to a residual vector population, without direct transmission between cattle, (iii) combination of both above mentioned mechanisms. Multi-model inference methods resulted in a model incorporating both a low level RVFV winter vector-borne transmission and a direct transmission between animals when viraemic cows calve. Predictions satisfactorily reproduced field observations, 84% of cattle infections being attributed to vector-borne transmission, and 16% to direct transmission. These results appeared robust according to the sensitivity analysis. Interweaving between agricultural works in rice fields, seasonality of

  9. A spatially explicit metapopulation model and cattle trade analysis suggests key determinants for the recurrent circulation of rift valley Fever virus in a pilot area of madagascar highlands.

    Directory of Open Access Journals (Sweden)

    Gaëlle Nicolas

    2014-12-01

    Full Text Available Rift Valley fever (RVF is a vector-borne zoonotic disease that causes high morbidity and mortality in ruminants. In 2008-2009, a RVF outbreak affected the whole Madagascar island, including the Anjozorobe district located in Madagascar highlands. An entomological survey showed the absence of Aedes among the potential RVF virus (RVFV vector species identified in this area, and an overall low abundance of mosquitoes due to unfavorable climatic conditions during winter. No serological nor virological sign of infection was observed in wild terrestrial mammals of the area, suggesting an absence of wild RVF virus (RVFV reservoir. However, a three years serological and virological follow-up in cattle showed a recurrent RVFV circulation. The objective of this study was to understand the key determinants of this unexpected recurrent transmission. To achieve this goal, a spatial deterministic discrete-time metapopulation model combined with cattle trade network was designed and parameterized to reproduce the local conditions using observational data collected in the area. Three scenarios that could explain the RVFV recurrent circulation in the area were analyzed: (i RVFV overwintering thanks to a direct transmission between cattle when viraemic cows calve, vectors being absent during the winter, (ii a low level vector-based circulation during winter thanks to a residual vector population, without direct transmission between cattle, (iii combination of both above mentioned mechanisms. Multi-model inference methods resulted in a model incorporating both a low level RVFV winter vector-borne transmission and a direct transmission between animals when viraemic cows calve. Predictions satisfactorily reproduced field observations, 84% of cattle infections being attributed to vector-borne transmission, and 16% to direct transmission. These results appeared robust according to the sensitivity analysis. Interweaving between agricultural works in rice fields

  10. Neural network models of learning and categorization in multigame experiments

    Directory of Open Access Journals (Sweden)

    Davide eMarchiori

    2011-12-01

    Full Text Available Previous research has shown that regret-driven neural networks predict behavior in repeated completely mixed games remarkably well, substantially equating the performance of the most accurate established models of learning. This result prompts the question of what is the added value of modeling learning through neural networks. We submit that this modeling approach allows for models that are able to distinguish among and respond differently to different payoff structures. Moreover, the process of categorization of a game is implicitly carried out by these models, thus without the need of any external explicit theory of similarity between games. To validate our claims, we designed and ran two multigame experiments in which subjects faced, in random sequence, different instances of two completely mixed 2x2 games. Then, we tested on our experimental data two regret-driven neural network models, and compared their performance with that of other established models of learning and Nash equilibrium.

  11. Dynamic Experiments and Constitutive Model Performance for Polycarbonate

    Science.gov (United States)

    2014-07-01

    Storage and loss tangent moduli for PC; DMA experiments performed at 1 Hz and shift at 100 Hz showing the  and transition regions using the...author would also like to thank Dr. Adam D. Mulliken for courteously providing the experimental results and the Abaqus version of the model and...exponential factor . In 1955, the Ree-Eyring model further accounted for microstructural mechanisms by relating molecular motions to yield behavior

  12. Mechanical Interaction in Pressurized Pipe Systems: Experiments and Numerical Models

    OpenAIRE

    Simão, Mariana; Mora-Rodriguez, Jesus; Ramos, Helena

    2015-01-01

    The dynamic interaction between the unsteady flow occurrence and the resulting vibration of the pipe are analyzed based on experiments and numerical models. Waterhammer, structural dynamic and fluid–structure interaction (FSI) are the main subjects dealt with in this study. Firstly, a 1D model is developed based on the method of characteristics (MOC) using specific damping coefficients for initial components associated with rheological pipe material behavior, structural and fluid deformation...

  13. Thermal-hydraulic Experiments for Advanced Physical Model Development

    International Nuclear Information System (INIS)

    Song, Chulhwa

    2012-04-01

    The improvement of prediction models is needed to enhance the safety analysis capability through experimental database of local phenomena. To improve the two-phase interfacial area transport model, the various experiments were carried out with local two-phase interfacial structure test facilities. 2 Χ 2 and 6 Χ 6 rod bundle test facilities were used for the experiment on the droplet behavior. The experiments on the droplet behavior inside a heated rod bundle geometry. The experiments used GIRLS and JICO and CFD analysis were carried out to comprehend the local condensation of steam jet, turbulent jet induced by condensation and the thermal mixing in a pool. In order to develop a model for key phenomena of newly adapted safety system, experiments for boiling inside a pool and condensation in horizontal channel have been performed. An experimental database of the CHF (Critical Heat Flux) and PDO (Post-dryout) was constructed. The mechanism of the heat transfer enhancement by surface modifications in nano-fluid was investigated in boiling mode and rapid quenching mode. The special measurement techniques were developed. They are Double-sensor optical void probe, Optic Rod, PIV technique and UBIM system

  14. Experiments and Modeling of G-Jitter Fluid Mechanics

    Science.gov (United States)

    Leslie, F. W.; Ramachandran, N.; Whitaker, Ann F. (Technical Monitor)

    2002-01-01

    While there is a general understanding of the acceleration environment onboard an orbiting spacecraft, past research efforts in the modeling and analysis area have still not produced a general theory that predicts the effects of multi-spectral periodic accelerations on a general class of experiments nor have they produced scaling laws that a prospective experimenter can use to assess how an experiment might be affected by this acceleration environment. Furthermore, there are no actual flight experimental data that correlates heat or mass transport with measurements of the periodic acceleration environment. The present investigation approaches this problem with carefully conducted terrestrial experiments and rigorous numerical modeling for better understanding the effect of residual gravity and gentler on experiments. The approach is to use magnetic fluids that respond to an imposed magnetic field gradient in much the same way as fluid density responds to a gravitational field. By utilizing a programmable power source in conjunction with an electromagnet, both static and dynamic body forces can be simulated in lab experiments. The paper provides an overview of the technique and includes recent results from the experiments.

  15. Radon transport in fractured soil. Laboratory experiments and modelling

    International Nuclear Information System (INIS)

    Hoff, A.

    1997-10-01

    Radon (Rn-222) transport in fractured soil has been investigated by laboratory experiments and by modelling. Radon transport experiments have been performed with two sand columns (homogeneous and inhomogeneous) and one undisturbed clayey till column containing a net of preferential flow paths (root holes). A numerical model (the finite-element model FRACTRAN) and an analytic model (a pinhole model) have been applied in simulations if soil gas and radon transport in fractured soil. Experiments and model calculations are included in a discussion of radon entry rates into houses placed on fractured soil. The main conclusion is, that fractures does not in general alter transport of internally generated radon out of soil, when the pressure and flow conditions in the soil is comparable to the conditions prevailing under a house. This indicates the important result, that fractures in soil have no impact on radon entry into a house beyond that of an increased gas permeability, but a more thorough investigation of this subject is needed. Only in the case where the soil is exposed to large pressure gradients, relative to gradients induced by a house, may it be possible to observe effects of radon exchange between fractures and matrix. (au) 52 tabs., 60 ill., 5 refs

  16. First experiments results about the engineering model of Rapsodie

    International Nuclear Information System (INIS)

    Chalot, A.; Ginier, R.; Sauvage, M.

    1964-01-01

    This report deals with the first series of experiments carried out on the engineering model of Rapsodie and on an associated sodium facility set in a laboratory hall of Cadarache. It conveys more precisely: 1/ - The difficulties encountered during the erection and assembly of the engineering model and a compilation of the results of the first series of experiments and tests carried out on this installation (loading of the subassemblies preheating, thermal chocks...). 2/ - The experiments and tests carried out on the two prototypes control rod drive mechanisms which brought to the choice for the design of the definitive drive mechanism. As a whole, the results proved the validity of the general design principles adopted for Rapsodie. (authors) [fr

  17. Design of spatial experiments: Model fitting and prediction

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, V.V.

    1996-03-01

    The main objective of the paper is to describe and develop model oriented methods and algorithms for the design of spatial experiments. Unlike many other publications in this area, the approach proposed here is essentially based on the ideas of convex design theory.

  18. The LHCf experiment modelling cosmic rays at LHC

    CERN Document Server

    Tricomi, A; Bonechi, L; Bongi, M; Castellini, G; D'Alessandro, R; Faus, A; Fukui, K; Haguenauer, M; Itow, Y; Kasahara, K; Macina, D; Mase, T; Masuda, K; Matsubara, Y; Mizuishi, M; Menjo, H; Muraki, Y; Papini, P; Perrot, A L; Ricciarini, S B; Sako, T; Shimizu, Y; Tamura, T; Taki, K; Torii, S; Tricomi, A; Turner, W C; Velasco, J; Watanabe, H; Yoshida, K

    2008-01-01

    The LHCf experiment at LHC has been designed to provide a calibration of nuclear interaction models used in cosmic ray physics up to energies relevant to test the region between the knee and the GZK cut-off. Details of the detector and its performances are discussed.

  19. Developing a new transformatory cultural tourism experience model / Milena Ivanovic

    OpenAIRE

    Ivanovic, Milena

    2014-01-01

    The research question addressed by this thesis is: To what degree the results of the statistical analysis will corroborate the main theoretical assumptions of the proposed theoretical model of new authentic transformatory cultural tourism experience as transmodern phenomenon of equality of two Cartesian levels of reality, material (objective authenticity) and experiential (constructive authenticity) in informing the intrapersonal existential authenticity as outcome transformato...

  20. Design of Experiments, Model Calibration and Data Assimilation

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Brian J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-07-30

    This presentation provides an overview of emulation, calibration and experiment design for computer experiments. Emulation refers to building a statistical surrogate from a carefully selected and limited set of model runs to predict unsampled outputs. The standard kriging approach to emulation of complex computer models is presented. Calibration refers to the process of probabilistically constraining uncertain physics/engineering model inputs to be consistent with observed experimental data. An initial probability distribution for these parameters is updated using the experimental information. Markov chain Monte Carlo (MCMC) algorithms are often used to sample the calibrated parameter distribution. Several MCMC algorithms commonly employed in practice are presented, along with a popular diagnostic for evaluating chain behavior. Space-filling approaches to experiment design for selecting model runs to build effective emulators are discussed, including Latin Hypercube Design and extensions based on orthogonal array skeleton designs and imposed symmetry requirements. Optimization criteria that further enforce space-filling, possibly in projections of the input space, are mentioned. Designs to screen for important input variations are summarized and used for variable selection in a nuclear fuels performance application. This is followed by illustration of sequential experiment design strategies for optimization, global prediction, and rare event inference.

  1. Wind Tunnel Experiments with Active Control of Bridge Section Model

    DEFF Research Database (Denmark)

    Hansen, Henriette I.; Thoft-Christensen, Palle

    This paper describes results of wind tunnel experiments with a bridge section model where movable flaps are integrated in the bridge girder so each flap is the streamlined part of the edge of the girder. This active control flap system is patented by COWIconsult and may be used to increase...

  2. Women's experiences of infertility - towards a relational model of care.

    Science.gov (United States)

    Cunningham, Nicola; Cunningham, Tom

    2013-12-01

    To consider the effectiveness of current models of patient-centred infertility care. Patient centredness is defined as one of six key dimensions of quality of care. In the field of infertility, a new interaction model of patient-centred infertility care is proposed. Despite positive moves, this model reveals shortcomings in knowledge about the lived experience of infertility and lacks the shift in attitudes and approach that effective patient-centred care requires. The study has a qualitative research design. Nine women living with and through infertility participated in online life-story interviews. Data were analysed using a layered strategy influenced by the voice-centred relational method, emphasising narrative content, form and function. Women reveal a complex experience. Three key themes were found: Approaching the clinic narratives are infused with personal expectations while deeply reflective of cultural expectations and social norms. Relatedness recognises women's experiences cannot be neatly separated into distinct domains. Liminality and infertility describes women's experiences lost in transition through and beyond infertility treatment. The current model of patient-centred infertility care requires further development. Women in this study found themselves lost in transition and irrespective of treatment failure or success. Conceptual development must embrace a relational understanding of patient's experience to ensure that patient-centred infertility care is realistic and relevant to patients, clinical staff and the system as a whole. Psychosocial skills are recognised as core competences for fertility nurses. A relational conceptualisation of patient's experiences, living with and through infertility, provides further information for the development of staff and enhanced knowledge and practice skills. © 2013 John Wiley & Sons Ltd.

  3. Deepening Sleep by Hypnotic Suggestion

    Science.gov (United States)

    Cordi, Maren J.; Schlarb, Angelika A.; Rasch, Björn

    2014-01-01

    Study Objectives: Slow wave sleep (SWS) plays a critical role in body restoration and promotes brain plasticity; however, it markedly declines across the lifespan. Despite its importance, effective tools to increase SWS are rare. Here we tested whether a hypnotic suggestion to “sleep deeper” extends the amount of SWS. Design: Within-subject, placebo-controlled crossover design. Setting: Sleep laboratory at the University of Zurich, Switzerland. Participants: Seventy healthy females 23.27 ± 3.17 y. Intervention: Participants listened to an auditory text with hypnotic suggestions or a control tape before napping for 90 min while high-density electroencephalography was recorded. Measurements and Results: After participants listened to the hypnotic suggestion to “sleep deeper” subsequent SWS was increased by 81% and time spent awake was reduced by 67% (with the amount of SWS or wake in the control condition set to 100%). Other sleep stages remained unaffected. Additionally, slow wave activity was significantly enhanced after hypnotic suggestions. During the hypnotic tape, parietal theta power increases predicted the hypnosis-induced extension of SWS. Additional experiments confirmed that the beneficial effect of hypnotic suggestions on SWS was specific to the hypnotic suggestion and did not occur in low suggestible participants. Conclusions: Our results demonstrate the effectiveness of hypnotic suggestions to specifically increase the amount and duration of slow wave sleep (SWS) in a midday nap using objective measures of sleep in young, healthy, suggestible females. Hypnotic suggestions might be a successful tool with a lower risk of adverse side effects than pharmacological treatments to extend SWS also in clinical and elderly populations. Citation: Cordi MJ, Schlarb AA, Rasch B. Deepening sleep by hypnotic suggestion. SLEEP 2014;37(6):1143-1152. PMID:24882909

  4. Metabolic profiling of synovial fluid in a unilateral ovine model of anterior cruciate ligament reconstruction of the knee suggests biomarkers for early osteoarthritis.

    Science.gov (United States)

    Mickiewicz, Beata; Heard, Bryan J; Chau, Johnny K; Chung, May; Hart, David A; Shrive, Nigel G; Frank, Cyril B; Vogel, Hans J

    2015-01-01

    Joint injuries and subsequent osteoarthritis (OA) are the leading causes of chronic joint disease. In this work, we explore the possibility of applying magnetic resonance spectroscopy-based metabolomics to detect host responses to an anterior cruciate ligament (ACL) reconstruction injury in synovial fluid in an ovine model. Using multivariate statistical analysis, we were able to distinguish post-injury joint samples (ACL and sham surgery) from the uninjured control samples, and as well the ACL surgical samples from sham surgery. In all samples there were 65 metabolites quantified, of which six could be suggested as biomarkers for early post-injury degenerative changes in the knee joints: isobutyrate, glucose, hydroxyproline, asparagine, serine, and uridine. Our results raise a cautionary note indicating that surgical interventions into the knee can result in metabolic alterations that need to be distinguished from those caused by the early onset of OA. Our findings illustrate the potential application of metabolomics as a diagnostic and prognostic tool for detection of injuries to the knee joint. The ability to detect a unique pattern of metabolic changes in the synovial fluid of sheep offers the possibility of extending the approach to precision medicine protocols in patient populations in the future. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  5. Stand-alone Inverter: Reviews, Models and Tests the exist system in Term of the Power Quality, and Suggestions to Design it

    Directory of Open Access Journals (Sweden)

    Ali Algaddafi

    2016-10-01

    Full Text Available Developments in power electronics have enabled the widespread application of Pulse Width Modulation (PWM inverters, notably for obtaining electricity from renewable systems. This paper critical review the previous studies in designing stand-alone inverter and modelling the inverter with two control loops to improve and provide a high-quality power of a stand-alone inverter. Multi-loop control techniques for a stand-alone inverter are utilised as the first loop is a capacitor current control to provide active damping and improve transient and steady state inverter performance. The capacitor current control is cheaper than inductor current control, where a small current sensing resistor is used. The second loop is the output voltage control that is used to improve the system performance and also control the output voltage. The power quality of the off-grid system is measured experimentally and compared with the grid power, showing power quality of off-grid system to be better than that of the grid. The suggestions and key findings to design the stand-alone inverter are given based in the reviewing of previous publications and from the literature’s point of view.

  6. Turkish experience with the use of IAEA planning models

    International Nuclear Information System (INIS)

    Fikret, H.

    1997-01-01

    Most of the IAEA planning methodologies for energy and electricity planning have been transferred to Turkey as part of Technical Co-operation projects on the subject matter. The transfer has been supplemented by adequate training to national experts through their participation in the above projects and in the training courses on these models organized by the IAEA. The experience gathered in the use of these models in Turkey is described in this paper, highlighting how the models are imbedded in the country's planning procedure for energy and electricity matters. (author). 7 figs, 6 tabs

  7. PARAMETRIC MODELING, CREATIVITY, AND DESIGN: TWO EXPERIENCES WITH ARCHITECTURE’ STUDENTS

    Directory of Open Access Journals (Sweden)

    Wilson Florio

    2012-02-01

    Full Text Available The aim of this article is to reflect on the use of the parametric modeling in two didactic experiences. The first experiment involved resources of the Paracloud program and its relation with the Rhinoceros program, that resulted in the production of physical models produced with the aid of the laser cutting. In the second experiment, the students had produced algorithms in the Grasshopper, resulting in families of structures and coverings. The study objects are both the physical models and digital algorithms resultants from this experimentation. For the analysis and synthesis of the results, we adopted four important assumptions: 1. the value of attitudes and environment of work; 2. the importance of experimentation and improvisation; 3. understanding of the design process as a situated act and as a ill-defined problem; 4. the inclusion of creative and critical thought in the disciplines. The results allow us to affirm that the parametric modeling stimulates creativity, therefore allowing combination of different parameters, that result in unexpected discoveries. Keywords: Teach-Learning, Parametric Modeling, Laser Cutter, Grasshopper, Design Process, Creativity.

  8. Modelling the Grimsel migration field experiments at PSI

    International Nuclear Information System (INIS)

    Heer, W.

    1997-01-01

    For several years tracer migration experiments have been performed at Nagra's Grimsel Test Site as a joint undertaking of Nagra, PNC and PSI. The aims of modelling the migration experiments are (1) to better understand the nuclide transport through crystalline rock; (2) to gain information on validity of methods and correlating parameters; (3) to improve models for safety assessments. The PSI modelling results, presented here, show a consistent picture for the investigated tracers (the non-sorbing uranine, the weakly sorbing sodium, the moderately sorbing strontium and the more strongly sorbing cesium). They represent an important step in building up confidence in safety assessments for radioactive waste repositories. (author) 5 figs., 1 tab., 12 refs

  9. Discrete fracture modelling for the Stripa tracer validation experiment predictions

    International Nuclear Information System (INIS)

    Dershowitz, W.; Wallmann, P.

    1992-02-01

    Groundwater flow and transport through three-dimensional networks of discrete fractures was modeled to predict the recovery of tracer from tracer injection experiments conducted during phase 3 of the Stripa site characterization and validation protect. Predictions were made on the basis of an updated version of the site scale discrete fracture conceptual model used for flow predictions and preliminary transport modelling. In this model, individual fractures were treated as stochastic features described by probability distributions of geometric and hydrologic properties. Fractures were divided into three populations: Fractures in fracture zones near the drift, non-fracture zone fractures within 31 m of the drift, and fractures in fracture zones over 31 meters from the drift axis. Fractures outside fracture zones are not modelled beyond 31 meters from the drift axis. Transport predictions were produced using the FracMan discrete fracture modelling package for each of five tracer experiments. Output was produced in the seven formats specified by the Stripa task force on fracture flow modelling. (au)

  10. Inborn and experience-dependent models of categorical brain organization. A position paper.

    Directory of Open Access Journals (Sweden)

    Guido eGainotti

    2015-01-01

    Full Text Available The present review aims to summarize the debate in contemporary neuroscience between inborn and experience-dependent models of conceptual representations that goes back to the description of category-specific semantic disorders for biological and artefact categories. Experience-dependent models suggest that categorical disorders are the by-product of the differential weighting of different sources of knowledge in the representation of biological and artefact categories. These models maintain that semantic disorders are not really category-specific, because they do not respect the boundaries between different categories. They also argue that the brain structures disrupted in a given type of category-specific semantic disorder should correspond to the areas of convergence of the sensory-motor information which play a major role in the construction of that category. Furthermore, they provide a simple interpretation of gender-related categorical effects and are supported by studies that have assessed the importance of prior experience in the cortical representation of objects On the other hand, inborn models maintain that category-specific semantic disorders reflect the disruption of innate brain networks, which are shaped by natural selection to allow rapid identification of objects that are very relevant for survival. From the empirical point of view, these models are mainly supported by observations made in blind subjects, which suggest that visual experience is not necessary for the emergence of category-specificity in the ventral stream of visual processing. The weight of data supporting experience-dependent and inborn models are thoroughly discussed, stressing the fact observations made in blind subjects are still the subject of intense debate, but concluding that at the present state of knowledge it is not possible to choose between experience-dependent and inborn models of conceptual representations.

  11. Dynamically Scaled Model Experiment of a Mooring Cable

    Directory of Open Access Journals (Sweden)

    Lars Bergdahl

    2016-01-01

    Full Text Available The dynamic response of mooring cables for marine structures is scale-dependent, and perfect dynamic similitude between full-scale prototypes and small-scale physical model tests is difficult to achieve. The best possible scaling is here sought by means of a specific set of dimensionless parameters, and the model accuracy is also evaluated by two alternative sets of dimensionless parameters. A special feature of the presented experiment is that a chain was scaled to have correct propagation celerity for longitudinal elastic waves, thus providing perfect geometrical and dynamic scaling in vacuum, which is unique. The scaling error due to incorrect Reynolds number seemed to be of minor importance. The 33 m experimental chain could then be considered a scaled 76 mm stud chain with the length 1240 m, i.e., at the length scale of 1:37.6. Due to the correct elastic scale, the physical model was able to reproduce the effect of snatch loads giving rise to tensional shock waves propagating along the cable. The results from the experiment were used to validate the newly developed cable-dynamics code, MooDy, which utilises a discontinuous Galerkin FEM formulation. The validation of MooDy proved to be successful for the presented experiments. The experimental data is made available here for validation of other numerical codes by publishing digitised time series of two of the experiments.

  12. Thermal experiments in the model of ADS target

    International Nuclear Information System (INIS)

    Alexander, Efanov; Yuri, Orlov; Alexander, Sorokin; Eugeni, Ivanov; Galina, Bogoslovskaia; Ning, Li

    2002-01-01

    The paper presents thermal experiments performed in the SSC RF IPPE on the ADS window target model. Brief description of the model, specific features of structure, measurement system and some methodological approaches are presented. Eutectic lead-bismuth alloy is modeled here by eutectic sodium-potassium alloy. The following characteristics of the target model were measured directly and estimated by processing: coolant flow rate, model power, absolute temperature of the coolant with a distance from the membrane of the target, absolute temperature of the membrane surface, mean square value and pulsating component of coolant temperature, as well as membrane temperature. Measurements have shown a great pulsations of temperature existing at the membrane surface that must be taken into account in analysis of strength of real target system. Experimental temperature fields (present work) and velocity fields measured earlier make up a complete database for verification of 2D and 3D thermohydraulic codes. (author)

  13. E-health stakeholders experiences with clinical modelling and standardizations.

    Science.gov (United States)

    Gøeg, Kirstine Rosenbeck; Elberg, Pia Britt; Højen, Anne Randorff

    2015-01-01

    Stakeholders in e-health such as governance officials, health IT-implementers and vendors have to co-operate to achieve the goal of a future-proof interoperable e-health infrastructure. Co-operation requires knowledge on the responsibility and competences of stakeholder groups. To increase awareness on clinical modeling and standardization we conducted a workshop for Danish and a few Norwegian e-health stakeholders' and made them discuss their views on different aspects of clinical modeling using a theoretical model as a point of departure. Based on the model, we traced stakeholders' experiences. Our results showed there was a tendency that stakeholders were more familiar with e-health requirements than with design methods, clinical information models and clinical terminology as they are described in the scientific literature. The workshop made it possible for stakeholders to discuss their roles and expectations to each other.

  14. Future high precision experiments and new physics beyond Standard Model

    International Nuclear Information System (INIS)

    Luo, Mingxing.

    1993-01-01

    High precision (< 1%) electroweak experiments that have been done or are likely to be done in this decade are examined on the basis of Standard Model (SM) predictions of fourteen weak neutral current observables and fifteen W and Z properties to the one-loop level, the implications of the corresponding experimental measurements to various types of possible new physics that enter at the tree or loop level were investigated. Certain experiments appear to have special promise as probes of the new physics considered here

  15. Analysis of NIF experiments with the minimal energy implosion model

    International Nuclear Information System (INIS)

    Cheng, B.; Kwan, T. J. T.; Wang, Y. M.; Merrill, F. E.; Batha, S. H.; Cerjan, C. J.

    2015-01-01

    We apply a recently developed analytical model of implosion and thermonuclear burn to fusion capsule experiments performed at the National Ignition Facility that used low-foot and high-foot laser pulse formats. Our theoretical predictions are consistent with the experimental data. Our studies, together with neutron image analysis, reveal that the adiabats of the cold fuel in both low-foot and high-foot experiments are similar. That is, the cold deuterium-tritium shells in those experiments are all in a high adiabat state at the time of peak implosion velocity. The major difference between low-foot and high-foot capsule experiments is the growth of the shock-induced instabilities developed at the material interfaces which lead to fuel mixing with ablator material. Furthermore, we have compared the NIF capsules performance with the ignition criteria and analyzed the alpha particle heating in the NIF experiments. Our analysis shows that alpha heating was appreciable only in the high-foot experiments

  16. Methane emissions from rice paddies. Experiments and modelling

    International Nuclear Information System (INIS)

    Van Bodegom, P.M.

    2000-01-01

    This thesis describes model development and experimentation on the comprehension and prediction of methane (CH4) emissions from rice paddies. The large spatial and temporal variability in CH4 emissions and the dynamic non-linear relationships between processes underlying CH4 emissions impairs the applicability of empirical relations. Mechanistic concepts are therefore starting point of analysis throughout the thesis. The process of CH4 production was investigated by soil slurry incubation experiments at different temperatures and with additions of different electron donors and acceptors. Temperature influenced conversion rates and the competitiveness of microorganisms. The experiments were used to calibrate and validate a mechanistic model on CH4 production that describes competition for acetate and H2/CO2, inhibition effects and chemolithotrophic reactions. The redox sequence leading eventually to CH4 production was well predicted by the model, calibrating only the maximum conversion rates. Gas transport through paddy soil and rice plants was quantified by experiments in which the transport of SF6 was monitored continuously by photoacoustics. A mechanistic model on gas transport in a flooded rice system based on diffusion equations was validated by these experiments and could explain why most gases are released via plant mediated transport. Variability in root distribution led to highly variable gas transport. Experiments showed that CH4 oxidation in the rice rhizosphere was oxygen (O2) limited. Rice rhizospheric O2 consumption was dominated by chemical iron oxidation, and heterotrophic and methanotrophic respiration. The most abundant methanotrophs and heterotrophs were isolated and kinetically characterised. Based upon these experiments it was hypothesised that CH4 oxidation mainly occurred at microaerophilic, low acetate conditions not very close to the root surface. A mechanistic rhizosphere model that combined production and consumption of O2, carbon and iron

  17. Women's Educational Experience under Colonialism: Toward a Diachronic Model.

    Science.gov (United States)

    Barthel, Diane

    1985-01-01

    Introduces a three-stage historical model of female education in Africa during and since the colonial period. Suggests an historical tendency to educate only males, then an attempt to educate a limited number of females for "modern" roles. Contemporary situation presents educational opportunities for more women, but with subtle sexism…

  18. Hypnotic suggestion and cognitive neuroscience.

    Science.gov (United States)

    Oakley, David A; Halligan, Peter W

    2009-06-01

    The growing acceptance of consciousness as a legitimate field of enquiry and the availability of functional imaging has rekindled research interest in the use of hypnosis and suggestion to manipulate subjective experience and to gain insights into healthy and pathological cognitive functioning. Current research forms two strands. The first comprises studies exploring the cognitive and neural nature of hypnosis itself. The second employs hypnosis to explore known psychological processes using specifically targeted suggestions. An extension of this second approach involves using hypnotic suggestion to create clinically informed analogues of established structural and functional neuropsychological disorders. With functional imaging, this type of experimental neuropsychopathology offers a productive means of investigating brain activity involved in many symptom-based disorders and their related phenomenology.

  19. Dispersion modelling studies: the 1984 experiment in Angra dos Reis

    International Nuclear Information System (INIS)

    Martano, P.; Paschoa, A.S.

    1997-01-01

    The results of a numerical modelling of an atmospheric dispersion in Angra dos Reis (RJ, Brazil) are considered. A comparison between model results and monitored field concentrations is discussed from the point of view of its statistical as well as physical significance. Particular attention has been paid to the effects of the lack of homogeneity in the spatial scale (horizontal and vertical) and in the time scale (stationarity in the local meteorology), as they can be critical in coastal areas. Some suggestions are made about a real time modelling of the atmospheric dispersion on the considered site. (author)

  20. Optimal experiment design for identification of grey-box models

    DEFF Research Database (Denmark)

    Sadegh, Payman; Melgaard, Henrik; Madsen, Henrik

    1994-01-01

    Optimal experiment design is investigated for stochastic dynamic systems where the prior partial information about the system is given as a probability distribution function in the system parameters. The concept of information is related to entropy reduction in the system through Lindley's measure...... estimation results in a considerable reduction of the experimental length. Besides, it is established that the physical knowledge of the system enables us to design experiments, with the goal of maximizing information about the physical parameters of interest....... of average information, and the relationship between the choice of information related criteria and some estimators (MAP and MLE) is established. A continuous time physical model of the heat dynamics of a building is considered and the results show that performing an optimal experiment corresponding to a MAP...

  1. A New Tube Gastrostomy Model in Animal Experiments

    Directory of Open Access Journals (Sweden)

    Atakan Sezer

    2013-01-01

    Full Text Available Aim: The orogastric route is the most preferred application method in the vast majority of the animal experiments in which application can be achieved by adding the material to the water of the experiment animal, through an orogastric tube or with a surgically managed ostomy. Material and Method: This experiment was constructed with twelve male Sprague-Dawley rats which were randomly assigned to one of two groups consist of control group ( group C, n: 6 and tube gastrostomy group ( group TG, n: 6.A novel and simple gastrostomy tube was derivated from a silicone foley catheter. Tube gastrostomy apparatus was constituted with a silicone foley catheter (6 French. In the group TG an incision was performed, and the stomach was visualized. A 1 cm incision was made in the midline and opening of the peritoneum. Anchoring sutures were placed and anterior gastric wall was lifted. The gastric wall is then opened. The apparatus was placed into the stomach and pulled through from a tunnel under the skin and fixed to the lateral abdominal wall with a 2/0 silk suture. Result: The procedure was ended in the 10th day of experiment. No mortality was observed in group C. The rats were monitored daily and no abnormal behavior consists of self harming incision site, resistance to oral intake or attending to displace. There was statistically significant difference in increasing alanine transaminase level (p<0.05 and decrease in the total protein and body weight (p<0.05 at the group TG at the end of experiment. There was significant increase in urea levels in Group C (p<0.05 at the end of experiment. The statistically significant decrease was observed in the same period in group C between aspartate transaminase, albumin, total protein, and body weight (p<0.05.  Glucose (p=0.047 and aspartate transaminase (p=0.050 level decrease changes and weight loose (p=0.034 from preoperative period to the end of the experiment between gastrostomy and laparotomy groups were

  2. Probabilistic modeling of systematic errors in two-hybrid experiments.

    Science.gov (United States)

    Sontag, David; Singh, Rohit; Berger, Bonnie

    2007-01-01

    We describe a novel probabilistic approach to estimating errors in two-hybrid (2H) experiments. Such experiments are frequently used to elucidate protein-protein interaction networks in a high-throughput fashion; however, a significant challenge with these is their relatively high error rate, specifically, a high false-positive rate. We describe a comprehensive error model for 2H data, accounting for both random and systematic errors. The latter arise from limitations of the 2H experimental protocol: in theory, the reporting mechanism of a 2H experiment should be activated if and only if the two proteins being tested truly interact; in practice, even in the absence of a true interaction, it may be activated by some proteins - either by themselves or through promiscuous interaction with other proteins. We describe a probabilistic relational model that explicitly models the above phenomenon and use Markov Chain Monte Carlo (MCMC) algorithms to compute both the probability of an observed 2H interaction being true as well as the probability of individual proteins being self-activating/promiscuous. This is the first approach that explicitly models systematic errors in protein-protein interaction data; in contrast, previous work on this topic has modeled errors as being independent and random. By explicitly modeling the sources of noise in 2H systems, we find that we are better able to make use of the available experimental data. In comparison with Bader et al.'s method for estimating confidence in 2H predicted interactions, the proposed method performed 5-10% better overall, and in particular regimes improved prediction accuracy by as much as 76%. http://theory.csail.mit.edu/probmod2H

  3. Thermal-hydraulic Experiments for Advanced Physical Model Development

    International Nuclear Information System (INIS)

    Song, Chul Hwa; Baek, W. P.; Yoon, B. J.

    2010-04-01

    The improvement of prediction models is needed to enhance the safety analysis capability through the fine measurements of local phenomena. To improve the two-phase interfacial area transport model, the various experiments were carried out used SUBO and DOBO. 2x2 and 6x6 rod bundle test facilities were used for the experiment on the droplet behavior. The experiments on the droplet behavior inside a heated rod bundle were focused on the break-up of droplets induced by a spacer grid in a rod bundle geometry. The experiments used GIRLS and JICO and CFD analysis were carried out to comprehend the local condensation of steam jet, turbulent jet induced by condensation and the thermal mixing in a pool. An experimental database of the CHF (Critical Heat Flux) and PDO (Post-dryout) had been constructed. The mechanism of the heat transfer enhancement by surface modifications in nano-fluid was investigated in boiling mode and rapid quenching mode. The special measurement techniques were developed. They are Double -sensor optical void probe, Optic Rod, PIV technique and UBIM system

  4. Historical and idealized climate model experiments: an EMIC intercomparison

    DEFF Research Database (Denmark)

    Eby, M.; Weaver, A. J.; Alexander, K.

    2012-01-01

    Both historical and idealized climate model experiments are performed with a variety of Earth System Models of Intermediate Complexity (EMICs) as part of a community contribution to the Intergovernmental Panel on Climate Change Fifth Assessment Report. Historical simulations start at 850 CE...... and continue through to 2005. The standard simulations include changes in forcing from solar luminosity, Earth's orbital configuration, CO2, additional greenhouse gases, land-use, and sulphate and volcanic aerosols. In spite of very different modelled pre-industrial global surface air temperatures...... the Medieval Climate Anomaly and the Little Ice Age estimated from paleoclimate reconstructions. This in turn could be a result of errors in the reconstructions of volcanic and/or solar radiative forcing used to drive the models or the incomplete representation of certain processes or variability within...

  5. An energetic model for macromolecules unfolding in stretching experiments

    Science.gov (United States)

    De Tommasi, D.; Millardi, N.; Puglisi, G.; Saccomandi, G.

    2013-01-01

    We propose a simple approach, based on the minimization of the total (entropic plus unfolding) energy of a two-state system, to describe the unfolding of multi-domain macromolecules (proteins, silks, polysaccharides, nanopolymers). The model is fully analytical and enlightens the role of the different energetic components regulating the unfolding evolution. As an explicit example, we compare the analytical results with a titin atomic force microscopy stretch-induced unfolding experiment showing the ability of the model to quantitatively reproduce the experimental behaviour. In the thermodynamic limit, the sawtooth force–elongation unfolding curve degenerates to a constant force unfolding plateau. PMID:24047874

  6. Mangling the models: Real-life experiences in voluntary siting

    International Nuclear Information System (INIS)

    Roche, C.S.

    1993-01-01

    Social scientists are accumulating a growing body of research to guide the development of communications models for siting controversial facilities. The models emphasize building consensus by involving all stakeholders, including opponents, in the decision-making process from its earliest stages. Communications should focus on issues and concerns that are most relevant to the people in the involved community. Finally, trust must be built through local control of the decision-making process. This paper presents experiences in the voluntary siting process for the Monitored Retrievable Storage (MRS) facility for spent nuclear fuel in three locations: Grant County, North Dakota, Fremont County, Wyoming, and the Mescalero Apache nation in New Mexico

  7. Sensitivity experiments to mountain representations in spectral models

    Directory of Open Access Journals (Sweden)

    U. Schlese

    2000-06-01

    Full Text Available This paper describes a set of sensitivity experiments to several formulations of orography. Three sets are considered: a "Standard" orography consisting of an envelope orography produced originally for the ECMWF model, a"Navy" orography directly from the US Navy data and a "Scripps" orography based on the data set originally compiled several years ago at Scripps. The last two are mean orographies which do not use the envelope enhancement. A new filtering technique for handling the problem of Gibbs oscillations in spectral models has been used to produce the "Navy" and "Scripps" orographies, resulting in smoother fields than the "Standard" orography. The sensitivity experiments show that orography is still an important factor in controlling the model performance even in this class of models that use a semi-lagrangian formulation for water vapour, that in principle should be less sensitive to Gibbs oscillations than the Eulerian formulation. The largest impact can be seen in the stationary waves (asymmetric part of the geopotential at 500 mb where the differences in total height and spatial pattern generate up to 60 m differences, and in the surface fields where the Gibbs removal procedure is successful in alleviating the appearance of unrealistic oscillations over the ocean. These results indicate that Gibbs oscillations also need to be treated in this class of models. The best overall result is obtained using the "Navy" data set, that achieves a good compromise between amplitude of the stationary waves and smoothness of the surface fields.

  8. Development of Eulerian Code Modeling for ICF Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, Paul A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-02-27

    One of the most pressing unexplained phenomena standing in the way of ICF ignition is understanding mix and how it interacts with burn. Experiments were being designed and fielded as part of the Defect-Induced Mix Experiment (DIME) project to obtain data about the extent of material mix and how this mix influenced burn. Experiments on the Omega laser and National Ignition Facility (NIF) provided detailed data for comparison to the Eulerian code RAGE1. The Omega experiments were able to resolve the mix and provide “proof of principle” support for subsequent NIF experiments, which were fielded from July 2012 through June 2013. The Omega shots were fired at least once per year between 2009 and 2012. RAGE was not originally designed to model inertial confinement fusion (ICF) implosions. It still lacks lasers, so the code has been validated using an energy source. To test RAGE, the simulation output is compared to data and by means of postprocessing tools that were developed. Here, the various postprocessing tools are described with illustrative examples.

  9. Global food insecurity. treatment of major food crops with elevated carbon dioxide or ozone under large-scale fully open-air conditions suggests recent models may have overestimated future yields.

    Science.gov (United States)

    Long, Stephen P; Ainsworth, Elizabeth A; Leakey, Andrew D B; Morgan, Patrick B

    2005-11-29

    Predictions of yield for the globe's major grain and legume arable crops suggest that, with a moderate temperature increase, production may increase in the temperate zone, but decline in the tropics. In total, global food supply may show little change. This security comes from inclusion of the direct effect of rising carbon dioxide (CO2) concentration, [CO2], which significantly stimulates yield by decreasing photorespiration in C3 crops and transpiration in all crops. Evidence for a large response to [CO2] is largely based on studies made within chambers at small scales, which would be considered unacceptable for standard agronomic trials of new cultivars or agrochemicals. Yet, predictions of the globe's future food security are based on such inadequate information. Free-Air Concentration Enrichment (FACE) technology now allows investigation of the effects of rising [CO2] and ozone on field crops under fully open-air conditions at an agronomic scale. Experiments with rice, wheat, maize and soybean show smaller increases in yield than anticipated from studies in chambers. Experiments with increased ozone show large yield losses (20%), which are not accounted for in projections of global food security. These findings suggest that current projections of global food security are overoptimistic. The fertilization effect of CO2 is less than that used in many models, while rising ozone will cause large yield losses in the Northern Hemisphere. Unfortunately, FACE studies have been limited in geographical extent and interactive effects of CO2, ozone and temperature have yet to be studied. Without more extensive study of the effects of these changes at an agronomic scale in the open air, our ever-more sophisticated models will continue to have feet of clay.

  10. Opinion Formation by Social Influence: From Experiments to Modeling.

    Science.gov (United States)

    Chacoma, Andrés; Zanette, Damián H

    2015-01-01

    Predicting different forms of collective behavior in human populations, as the outcome of individual attitudes and their mutual influence, is a question of major interest in social sciences. In particular, processes of opinion formation have been theoretically modeled on the basis of a formal similarity with the dynamics of certain physical systems, giving rise to an extensive collection of mathematical models amenable to numerical simulation or even to exact solution. Empirical ground for these models is however largely missing, which confine them to the level of mere metaphors of the real phenomena they aim at explaining. In this paper we present results of an experiment which quantifies the change in the opinions given by a subject on a set of specific matters under the influence of others. The setup is a variant of a recently proposed experiment, where the subject's confidence on his or her opinion was evaluated as well. In our realization, which records the quantitative answers of 85 subjects to 20 questions before and after an influence event, the focus is put on characterizing the change in answers and confidence induced by such influence. Similarities and differences with the previous version of the experiment are highlighted. We find that confidence changes are to a large extent independent of any other recorded quantity, while opinion changes are strongly modulated by the original confidence. On the other hand, opinion changes are not influenced by the initial difference with the reference opinion. The typical time scales on which opinion varies are moreover substantially longer than those of confidence change. Experimental results are then used to estimate parameters for a dynamical agent-based model of opinion formation in a large population. In the context of the model, we study the convergence to full consensus and the effect of opinion leaders on the collective distribution of opinions.

  11. Ontological and Epistemological Issues Regarding Climate Models and Computer Experiments

    Science.gov (United States)

    Vezer, M. A.

    2010-12-01

    Recent philosophical discussions (Parker 2009; Frigg and Reiss 2009; Winsberg, 2009; Morgon 2002, 2003, 2005; Gula 2002) about the ontology of computer simulation experiments and the epistemology of inferences drawn from them are of particular relevance to climate science as computer modeling and analysis are instrumental in understanding climatic systems. How do computer simulation experiments compare with traditional experiments? Is there an ontological difference between these two methods of inquiry? Are there epistemological considerations that result in one type of inference being more reliable than the other? What are the implications of these questions with respect to climate studies that rely on computer simulation analysis? In this paper, I examine these philosophical questions within the context of climate science, instantiating concerns in the philosophical literature with examples found in analysis of global climate change. I concentrate on Wendy Parker’s (2009) account of computer simulation studies, which offers a treatment of these and other questions relevant to investigations of climate change involving such modelling. Two theses at the center of Parker’s account will be the focus of this paper. The first is that computer simulation experiments ought to be regarded as straightforward material experiments; which is to say, there is no significant ontological difference between computer and traditional experimentation. Parker’s second thesis is that some of the emphasis on the epistemological importance of materiality has been misplaced. I examine both of these claims. First, I inquire as to whether viewing computer and traditional experiments as ontologically similar in the way she does implies that there is no proper distinction between abstract experiments (such as ‘thought experiments’ as well as computer experiments) and traditional ‘concrete’ ones. Second, I examine the notion of materiality (i.e., the material commonality between

  12. Gravitational Acceleration Effects on Macrosegregation: Experiment and Computational Modeling

    Science.gov (United States)

    Leon-Torres, J.; Curreri, P. A.; Stefanescu, D. M.; Sen, S.

    1999-01-01

    Experiments were performed under terrestrial gravity (1g) and during parabolic flights (10-2 g) to study the solidification and macrosegregation patterns of Al-Cu alloys. Alloys having 2% and 5% Cu were solidified against a chill at two different cooling rates. Microscopic and Electron Microprobe characterization was used to produce microstructural and macrosegregation maps. In all cases positive segregation occurred next to the chill because shrinkage flow, as expected. This positive segregation was higher in the low-g samples, apparently because of the higher heat transfer coefficient. A 2-D computational model was used to explain the experimental results. The continuum formulation was employed to describe the macroscopic transports of mass, energy, and momentum, associated with the solidification phenomena, for a two-phase system. The model considers that liquid flow is driven by thermal and solutal buoyancy, and by solidification shrinkage. The solidification event was divided into two stages. In the first one, the liquid containing freely moving equiaxed grains was described through the relative viscosity concept. In the second stage, when a fixed dendritic network was formed after dendritic coherency, the mushy zone was treated as a porous medium. The macrosegregation maps and the cooling curves obtained during experiments were used for validation of the solidification and segregation model. The model can explain the solidification and macrosegregation patterns and the differences between low- and high-gravity results.

  13. RANS Modeling of Benchmark Shockwave / Boundary Layer Interaction Experiments

    Science.gov (United States)

    Georgiadis, Nick; Vyas, Manan; Yoder, Dennis

    2010-01-01

    This presentation summarizes the computations of a set of shock wave / turbulent boundary layer interaction (SWTBLI) test cases using the Wind-US code, as part of the 2010 American Institute of Aeronautics and Astronautics (AIAA) shock / boundary layer interaction workshop. The experiments involve supersonic flows in wind tunnels with a shock generator that directs an oblique shock wave toward the boundary layer along one of the walls of the wind tunnel. The Wind-US calculations utilized structured grid computations performed in Reynolds-averaged Navier-Stokes mode. Three turbulence models were investigated: the Spalart-Allmaras one-equation model, the Menter Shear Stress Transport wavenumber-angular frequency two-equation model, and an explicit algebraic stress wavenumber-angular frequency formulation. Effects of grid resolution and upwinding scheme were also considered. The results from the CFD calculations are compared to particle image velocimetry (PIV) data from the experiments. As expected, turbulence model effects dominated the accuracy of the solutions with upwinding scheme selection indicating minimal effects.!

  14. Integrated Experiment and Modeling of Insensitive High Explosives

    Science.gov (United States)

    Stewart, D. Scott; Lambert, David E.; Yoo, Sunhee; Lieber, Mark; Holman, Steven

    2009-12-01

    New design paradigms for insensitive high explosives are being sought for use in munitions applications that require enhanced safety, reliability and performance. We describe recent work of our group that uses an integrated approach to develop predictive models, guided by experiments. Insensitive explosive can have relatively longer detonation reaction zones and slower reaction rates than their sensitive counterparts. We employ reactive flow models that are constrained by detonation shock dynamics (DSD) to pose candidate predictive models. We discuss the variation of the pressure dependent reaction rate exponent and reaction order on the length of the supporting reaction zone, the detonation velocity curvature relation, the computed critical energy required for initiation, the relation between the diameter effect curve and the corresponding normal detonation velocity curvature relation.

  15. Historical and idealized climate model experiments: an EMIC intercomparison

    DEFF Research Database (Denmark)

    Eby, M.; Weaver, A. J.; Alexander, K.

    2012-01-01

    and continue through to 2005. The standard simulations include changes in forcing from solar luminosity, Earth's orbital configuration, CO2, additional greenhouse gases, land-use, and sulphate and volcanic aerosols. In spite of very different modelled pre-industrial global surface air temperatures......Both historical and idealized climate model experiments are performed with a variety of Earth System Models of Intermediate Complexity (EMICs) as part of a community contribution to the Intergovernmental Panel on Climate Change Fifth Assessment Report. Historical simulations start at 850 CE......, are used to assess the contributions of different climate forcings to the overall climate and carbon cycle response. The response of surface air temperature is the linear sum of the individual forcings, while the carbon cycle response shows considerable synergy between land-use change and CO2

  16. Processes governing arsenic retardation on Pleistocene sediments: Adsorption experiments and model-based analysis

    Science.gov (United States)

    Rathi, Bhasker; Neidhardt, Harald; Berg, Michael; Siade, Adam; Prommer, Henning

    2017-05-01

    In many countries of south/south-east Asia, reliance on Pleistocene aquifers for the supply of low-arsenic groundwater has created the risk of inducing migration of high-arsenic groundwater from adjacent Holocene aquifers. Adsorption of arsenic onto mineral surfaces of Pleistocene sediments is an effective attenuation mechanism. However, little is known about the sorption under anoxic conditions, in particular the behavior of arsenite. We report the results of anoxic batch experiments investigating arsenite (1-25 µmol/L) adsorption onto Pleistocene sediments under a range of field-relevant conditions. The sorption of arsenite was nonlinear and decreased with increasing phosphate concentrations (3-60 µmol/L) while pH (range 6-8) had no effect on total arsenic sorption. To simulate the sorption experiments, we developed surface complexation models of varying complexity. The simulated concentrations of arsenite, arsenate, and phosphate were in good agreement for the isotherm and phosphate experiments while secondary geochemical processes affected the pH experiments. For the latter, the model-based analysis suggests that the formation of solution complexes between organic buffers and Mn(II) ions promoted the oxidation of arsenite involving naturally occurring Mn-oxides. Upscaling the batch experiment model to a reactive transport model for Pleistocene aquifers demonstrates strong arsenic retardation and could have useful implications in the management of arsenic-free Pleistocene aquifers.

  17. Multi-scale modelling for HEDP experiments on Orion

    Science.gov (United States)

    Sircombe, N. J.; Ramsay, M. G.; Hughes, S. J.; Hoarty, D. J.

    2016-05-01

    The Orion laser at AWE couples high energy long-pulse lasers with high intensity short-pulses, allowing material to be compressed beyond solid density and heated isochorically. This experimental capability has been demonstrated as a platform for conducting High Energy Density Physics material properties experiments. A clear understanding of the physics in experiments at this scale, combined with a robust, flexible and predictive modelling capability, is an important step towards more complex experimental platforms and ICF schemes which rely on high power lasers to achieve ignition. These experiments present a significant modelling challenge, the system is characterised by hydrodynamic effects over nanoseconds, driven by long-pulse lasers or the pre-pulse of the petawatt beams, and fast electron generation, transport, and heating effects over picoseconds, driven by short-pulse high intensity lasers. We describe the approach taken at AWE; to integrate a number of codes which capture the detailed physics for each spatial and temporal scale. Simulations of the heating of buried aluminium microdot targets are discussed and we consider the role such tools can play in understanding the impact of changes to the laser parameters, such as frequency and pre-pulse, as well as understanding effects which are difficult to observe experimentally.

  18. Medical students' emotional development in early clinical experience: a model.

    Science.gov (United States)

    Helmich, Esther; Bolhuis, Sanneke; Laan, Roland; Dornan, Tim; Koopmans, Raymond

    2014-08-01

    Dealing with emotions is a critical feature of professional behaviour. There are no comprehensive theoretical models, however, explaining how medical students learn about emotions. We aimed to explore factors affecting their emotions and how they learn to deal with emotions in themselves and others. During a first-year nursing attachment in hospitals and nursing homes, students wrote daily about their most impressive experiences, explicitly reporting what they felt, thought, and did. In a subsequent interview, they discussed those experiences in greater detail. Following a grounded theory approach, we conducted a constant comparative analysis, collecting and then interpreting data, and allowing the interpretation to inform subsequent data collection. Impressive experiences set up tensions, which gave rise to strong emotions. We identified four 'axes' along which tensions were experienced: 'idealism versus reality', 'critical distance versus adaptation', 'involvement versus detachment' and 'feeling versus displaying'. We found many factors, which influenced how respondents relieved those tensions. Their personal attributes and social relationships both inside and outside the medical community were important ones. Respondents' positions along the different dimensions, as determined by the balance between attributes and tensions, shaped their learning outcomes. Medical students' emotional development occurs through active participation in medical practice and having impressive experiences within relationships with patients and others on wards. Tensions along four dimensions give rise to strong emotions. Gaining insight into the many conditions that influence students' learning about emotions might support educators and supervisors in fostering medical students' emotional and professional development.

  19. Using 4P Marketing Model in Academic Libraries: An Experience

    OpenAIRE

    Mehdi Alipour Hafezi; Hassan Ashrafi Rizi; Zahra Kazempour; Mahri Shahbazi

    2013-01-01

    The present study mainly aims to demonstrate the weaknesses and strengths of using marketing principles in academic libraries and finally presenting some important suggestions in order to improve their marketing. This study proceeds through expressing the current marketing situation of studied academic libraries from the view point of 4P model. In this regard, the current situation is analyzed using a researcher-made questionnaire, and then the problems and shortcomings are highlighted in the...

  20. Dynamic crack initiation toughness : experiments and peridynamic modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Foster, John T.

    2009-10-01

    This is a dissertation on research conducted studying the dynamic crack initiation toughness of a 4340 steel. Researchers have been conducting experimental testing of dynamic crack initiation toughness, K{sub Ic}, for many years, using many experimental techniques with vastly different trends in the results when reporting K{sub Ic} as a function of loading rate. The dissertation describes a novel experimental technique for measuring K{sub Ic} in metals using the Kolsky bar. The method borrows from improvements made in recent years in traditional Kolsky bar testing by using pulse shaping techniques to ensure a constant loading rate applied to the sample before crack initiation. Dynamic crack initiation measurements were reported on a 4340 steel at two different loading rates. The steel was shown to exhibit a rate dependence, with the recorded values of K{sub Ic} being much higher at the higher loading rate. Using the knowledge of this rate dependence as a motivation in attempting to model the fracture events, a viscoplastic constitutive model was implemented into a peridynamic computational mechanics code. Peridynamics is a newly developed theory in solid mechanics that replaces the classical partial differential equations of motion with integral-differential equations which do not require the existence of spatial derivatives in the displacement field. This allows for the straightforward modeling of unguided crack initiation and growth. To date, peridynamic implementations have used severely restricted constitutive models. This research represents the first implementation of a complex material model and its validation. After showing results comparing deformations to experimental Taylor anvil impact for the viscoplastic material model, a novel failure criterion is introduced to model the dynamic crack initiation toughness experiments. The failure model is based on an energy criterion and uses the K{sub Ic} values recorded experimentally as an input. The failure model

  1. Topography of inland deltas: Observations, modeling, and experiments

    Science.gov (United States)

    Seybold, H. J.; Molnar, P.; Akca, D.; Doumi, M.; Cavalcanti Tavares, M.; Shinbrot, T.; Andrade, J. S.; Kinzelbach, W.; Herrmann, H. J.

    2010-04-01

    The topography of inland deltas is influenced by the water-sediment balance in distributary channels and local evaporation and seepage rates. In this letter a reduced complexity model is applied to simulate inland delta formation, and results are compared with the Okavango Delta, Botswana and with a laboratory experiment. We show that water loss in inland deltas produces fundamentally different dynamics of water and sediment transport than coastal deltas, especially deposition associated with expansion-contraction dynamics at the channel head. These dynamics lead to a systematic decrease in the mean topographic slope of the inland delta with distance from the apex following a power law with exponent α = -0.69 ± 0.02 where the data for both simulation and experiment can be collapsed onto a single curve. In coastal deltas, on the contrary, the slope increases toward the end of the deposition zone.

  2. Unconfined deflagrative explosions without turbulence: experiments and model

    International Nuclear Information System (INIS)

    Lannoy, A.

    1989-01-01

    This paper reviews laboratory, balloon and open field experiments which have been performed to study the deflagration regime in free air. In a first part, are considered different models available to estimate deflagrative unconfined explosions effects, without turbulence. Then, a description is given of the known performed tests, which indicate the effective scale of various experiments, their operating conditions and the type of measurements carried out. Results are presented and discussed. The influence on the explosion force of different parameters (fuel concentration gradients, flammable mixture shape and size, ignition energy) is estimated. The overall conclusion of this survey is that flammable mixtures drifting over open field and ignited, will burn with low flame speed and consequently will generate very weak pressure effects [fr

  3. RHIC/AGS Online Model Environments: Experiences and Design for AGS Modeling

    International Nuclear Information System (INIS)

    Brown, K.; Niederer, J.; Satogata, T.; Alai Tafti, A.; Tsoupas, N.; Zeijts, J. van

    1999-01-01

    The RHIC/AGS online modeling environment, a general client-server modeling package that supports cdev and straightforward integration of diverse computational modeling engines (CMEs), is being adapted to model the AGS and Booster at BNL. This implementation uses a version of MAD modified at BNL that allows traditional lattice structure analysis, single pass beam line analysis, multi-particle tracking, interactive graphics, and the use of field maps. The on-line model system is still under development, a real working prototype exists and is being tested. This paper describes the system and experience with its design and use for AGS and AGS Booster online modeling

  4. Mode I Failure of Armor Ceramics: Experiments and Modeling

    Science.gov (United States)

    Meredith, Christopher; Leavy, Brian

    2017-06-01

    The pre-notched edge on impact (EOI) experiment is a technique for benchmarking the damage and fracture of ceramics subjected to projectile impact. A cylindrical projectile impacts the edge of a thin rectangular plate with a pre-notch on the opposite edge. Tension is generated at the notch tip resulting in the initiation and propagation of a mode I crack back toward the impact edge. The crack can be quantitatively measured using an optical method called Digital Gradient Sensing, which measures the crack-tip deformation by simultaneously quantifying two orthogonal surface slopes via measuring small deflections of light rays from a specularly reflective surface around the crack. The deflections in ceramics are small so the high speed camera needs to have a very high pixel count. This work reports on the results from pre-crack EOI experiments of SiC and B4 C plates. The experimental data are quantitatively compared to impact simulations using an advanced continuum damage model. The Kayenta ceramic model in Alegra will be used to compare fracture propagation speeds, bifurcations and inhomogeneous initiation of failure will be compared. This will provide insight into the driving mechanisms required for the macroscale failure modeling of ceramics.

  5. A DIDATIC EXPERIENCE IN BIOCHEMISTRY LABWORKS: THEORETICALVERSUS EXPERIMENTAL MODEL

    Directory of Open Access Journals (Sweden)

    B.C Rossi-Rodrigues

    2008-05-01

    Full Text Available Biochemistry labworks are fundamental to both the instrumentation and  for  the  establishment of important concepts. The labworks of Basic  Biochemistry  (BB280 for Biology students at UNICAMP have gone through several  improvements. The labworks are  now  structured  from simple  activities to more complex ones, and aimed  to  the student’s  autonomy  development  in the experiments planning and execution  over  the teaching  semester. The first practical activity is on buffer systems, and   it is based  on  the confrontation of a theoretical model with the  lab experiments results.  First of all, the students  simulate  a Titration  in  a computational environment, where students lay a theoretical model from their knowledge. In the theoretical model the buffer parameters are set according to the teacher instructions, and the experiment conditions are also set and tested.  The simulation results are used for planning  the experiment and to compare with the experimental ones.  After having the simulations concluded and having the experiment planned the students  perform  the  in lab  Titration with the parameters established in the simulation. The results obtained by students are presented in a report. We analyzed the reports from 76 BB280’s students in 2007(night class and day class. The students identified as the main causes of the discrepancy between theoretical and experimental data: 1 experimental errors, related to the lack of technical skill 2 limitation of equipment used 3 unexpected behavior of the substances  used. In addition to the theoretical content related to  labwork, the confrontation between the  simulation and experimentation provided the students with ability  to identify the main aspects of which can influence the quality of the data obtained.

  6. Mechanical Interaction in Pressurized Pipe Systems: Experiments and Numerical Models

    Directory of Open Access Journals (Sweden)

    Mariana Simão

    2015-11-01

    Full Text Available The dynamic interaction between the unsteady flow occurrence and the resulting vibration of the pipe are analyzed based on experiments and numerical models. Waterhammer, structural dynamic and fluid–structure interaction (FSI are the main subjects dealt with in this study. Firstly, a 1D model is developed based on the method of characteristics (MOC using specific damping coefficients for initial components associated with rheological pipe material behavior, structural and fluid deformation, and type of anchored structural supports. Secondly a 3D coupled complex model based on Computational Fluid Dynamics (CFD, using a Finite Element Method (FEM, is also applied to predict and distinguish the FSI events. Herein, a specific hydrodynamic model of viscosity to replicate the operation of a valve was also developed to minimize the number of mesh elements and the complexity of the system. The importance of integrated analysis of fluid–structure interaction, especially in non-rigidity anchored pipe systems, is equally emphasized. The developed models are validated through experimental tests.

  7. Dynamics of vortices in complex wakes: Modeling, analysis, and experiments

    Science.gov (United States)

    Basu, Saikat

    The thesis develops singly-periodic mathematical models for complex laminar wakes which are formed behind vortex-shedding bluff bodies. These wake structures exhibit a variety of patterns as the bodies oscillate or are in close proximity of one another. The most well-known formation comprises two counter-rotating vortices in each shedding cycle and is popularly known as the von Karman vortex street. Of the more complex configurations, as a specific example, this thesis investigates one of the most commonly occurring wake arrangements, which consists of two pairs of vortices in each shedding period. The paired vortices are, in general, counter-rotating and belong to a more general definition of the 2P mode, which involves periodic release of four vortices into the flow. The 2P arrangement can, primarily, be sub-classed into two types: one with a symmetric orientation of the two vortex pairs about the streamwise direction in a periodic domain and the other in which the two vortex pairs per period are placed in a staggered geometry about the wake centerline. The thesis explores the governing dynamics of such wakes and characterizes the corresponding relative vortex motion. In general, for both the symmetric as well as the staggered four vortex periodic arrangements, the thesis develops two-dimensional potential flow models (consisting of an integrable Hamiltonian system of point vortices) that consider spatially periodic arrays of four vortices with their strengths being +/-Gamma1 and +/-Gamma2. Vortex formations observed in the experiments inspire the assumed spatial symmetry. The models demonstrate a number of dynamic modes that are classified using a bifurcation analysis of the phase space topology, consisting of level curves of the Hamiltonian. Despite the vortex strengths in each pair being unequal in magnitude, some initial conditions lead to relative equilibrium when the vortex configuration moves with invariant size and shape. The scaled comparisons of the

  8. Discrete Element Modeling (DEM) of Triboelectrically Charged Particles: Revised Experiments

    Science.gov (United States)

    Hogue, Michael D.; Calle, Carlos I.; Curry, D. R.; Weitzman, P. S.

    2008-01-01

    In a previous work, the addition of basic screened Coulombic electrostatic forces to an existing commercial discrete element modeling (DEM) software was reported. Triboelectric experiments were performed to charge glass spheres rolling on inclined planes of various materials. Charge generation constants and the Q/m ratios for the test materials were calculated from the experimental data and compared to the simulation output of the DEM software. In this paper, we will discuss new values of the charge generation constants calculated from improved experimental procedures and data. Also, planned work to include dielectrophoretic, Van der Waals forces, and advanced mechanical forces into the software will be discussed.

  9. Numerical Experiments Based on the Catastrophe Model of Solar Eruptions

    Science.gov (United States)

    Xie, X. Y.; Ziegler, U.; Mei, Z. X.; Wu, N.; Lin, J.

    2017-11-01

    On the basis of the catastrophe model developed by Isenberg et al., we use the NIRVANA code to perform the magnetohydrodynamics (MHD) numerical experiments to look into various behaviors of the coronal magnetic configuration that includes a current-carrying flux rope used to model the prominence levitating in the corona. These behaviors include the evolution in equilibrium heights of the flux rope versus the change in the background magnetic field, the corresponding internal equilibrium of the flux rope, dynamic properties of the flux rope after the system loses equilibrium, as well as the impact of the referential radius on the equilibrium heights of the flux rope. In our calculations, an empirical model of the coronal density distribution given by Sittler & Guhathakurta is used, and the physical diffusion is included. Our experiments show that the deviation of simulations in the equilibrium heights from the theoretical results exists, but is not apparent, and the evolutionary features of the two results are similar. If the flux rope is initially locate at the stable branch of the theoretical equilibrium curve, the flux rope will quickly reach the equilibrium position in the simulation after several rounds of oscillations as a result of the self-adjustment of the system; and the flux rope lose the equilibrium if the initial location of the flux rope is set at the critical point on the theoretical equilibrium curve. Correspondingly, the internal equilibrium of the flux rope can be reached as well, and the deviation from the theoretical results is somewhat apparent since the approximation of the small radius of the flux rope is lifted in our experiments, but such deviation does not affect the global equilibrium in the system. The impact of the referential radius on the equilibrium heights of the flux rope is consistent with the prediction of the theory. Our calculations indicate that the motion of the flux rope after the loss of equilibrium is consistent with which

  10. Dissolution-precipitation processes in tank experiments for testing numerical models for reactive transport calculations: Experiments and modelling

    Science.gov (United States)

    Poonoosamy, Jenna; Kosakowski, Georg; Van Loon, Luc R.; Mäder, Urs

    2015-06-01

    In the context of testing reactive transport codes and their underlying conceptual models, a simple 2D reactive transport experiment was developed. The aim was to use simple chemistry and design a reproducible and fast to conduct experiment, which is flexible enough to include several process couplings: advective-diffusive transport of solutes, effect of liquid phase density on advective transport, and kinetically controlled dissolution/precipitation reactions causing porosity changes. A small tank was filled with a reactive layer of strontium sulfate (SrSO4) of two different grain sizes, sandwiched between two layers of essentially non-reacting quartz sand (SiO2). A highly concentrated solution of barium chloride was injected to create an asymmetric flow field. Once the barium chloride reached the reactive layer, it forced the transformation of strontium sulfate into barium sulfate (BaSO4). Due to the higher molar volume of barium sulfate, its precipitation caused a decrease of porosity and lowered the permeability. Changes in the flow field were observed with help of dye tracer tests. The experiments were modelled using the reactive transport code OpenGeosys-GEM. Tests with non-reactive tracers performed prior to barium chloride injection, as well as the density-driven flow (due to the high concentration of barium chloride solution), could be well reproduced by the numerical model. To reproduce the mineral bulk transformation with time, two populations of strontium sulfate grains with different kinetic rates of dissolution were applied. However, a default porosity permeability relationship was unable to account for measured pressure changes. Post mortem analysis of the strontium sulfate reactive medium provided useful information on the chemical and structural changes occurring at the pore scale at the interface that were considered in our model to reproduce the pressure evolution with time.

  11. Modelling hot electron generation in short pulse target heating experiments

    Directory of Open Access Journals (Sweden)

    Sircombe N.J.

    2013-11-01

    Full Text Available Target heating experiments planned for the Orion laser facility, and electron beam driven fast ignition schemes, rely on the interaction of a short pulse high intensity laser with dense material to generate a flux of energetic electrons. It is essential that the characteristics of this electron source are well known in order to inform transport models in radiation hydrodynamics codes and allow effective evaluation of experimental results and forward modelling of future campaigns. We present results obtained with the particle in cell (PIC code EPOCH for realistic target and laser parameters, including first and second harmonic light. The hot electron distributions are characterised and their implications for onward transport and target heating are considered with the aid of the Monte-Carlo transport code THOR.

  12. Morphogenesis and pattern formation in biological systems experiments and models

    CERN Document Server

    Noji, Sumihare; Ueno, Naoto; Maini, Philip

    2003-01-01

    A central goal of current biology is to decode the mechanisms that underlie the processes of morphogenesis and pattern formation. Concerned with the analysis of those phenomena, this book covers a broad range of research fields, including developmental biology, molecular biology, plant morphogenesis, ecology, epidemiology, medicine, paleontology, evolutionary biology, mathematical biology, and computational biology. In Morphogenesis and Pattern Formation in Biological Systems: Experiments and Models, experimental and theoretical aspects of biology are integrated for the construction and investigation of models of complex processes. This collection of articles on the latest advances by leading researchers not only brings together work from a wide spectrum of disciplines, but also provides a stepping-stone to the creation of new areas of discovery.

  13. First experience of vectorizing electromagnetic physics models for detector simulation

    Energy Technology Data Exchange (ETDEWEB)

    Amadio, G. [Sao Paulo State U.; Apostolakis, J. [CERN; Bandieramonte, M. [Catania Astrophys. Observ.; Bianchini, C. [Mackenzie Presbiteriana U.; Bitzes, G. [CERN; Brun, R. [CERN; Canal, P. [Fermilab; Carminati, F. [CERN; Licht, J.de Fine [U. Copenhagen (main); Duhem, L. [Intel, Santa Clara; Elvira, D. [Fermilab; Gheata, A. [CERN; Jun, S. Y. [Fermilab; Lima, G. [Fermilab; Novak, M. [CERN; Presbyterian, M. [Bhabha Atomic Res. Ctr.; Shadura, O. [CERN; Seghal, R. [Bhabha Atomic Res. Ctr.; Wenzel, S. [CERN

    2015-12-23

    The recent emergence of hardware architectures characterized by many-core or accelerated processors has opened new opportunities for concurrent programming models taking advantage of both SIMD and SIMT architectures. The GeantV vector prototype for detector simulations has been designed to exploit both the vector capability of mainstream CPUs and multi-threading capabilities of coprocessors including NVidia GPUs and Intel Xeon Phi. The characteristics of these architectures are very different in terms of the vectorization depth, parallelization needed to achieve optimal performance or memory access latency and speed. An additional challenge is to avoid the code duplication often inherent to supporting heterogeneous platforms. In this paper we present the first experience of vectorizing electromagnetic physics models developed for the GeantV project.

  14. Social aggregation in pea aphids: experiment and random walk modeling.

    Science.gov (United States)

    Nilsen, Christa; Paige, John; Warner, Olivia; Mayhew, Benjamin; Sutley, Ryan; Lam, Matthew; Bernoff, Andrew J; Topaz, Chad M

    2013-01-01

    From bird flocks to fish schools and ungulate herds to insect swarms, social biological aggregations are found across the natural world. An ongoing challenge in the mathematical modeling of aggregations is to strengthen the connection between models and biological data by quantifying the rules that individuals follow. We model aggregation of the pea aphid, Acyrthosiphon pisum. Specifically, we conduct experiments to track the motion of aphids walking in a featureless circular arena in order to deduce individual-level rules. We observe that each aphid transitions stochastically between a moving and a stationary state. Moving aphids follow a correlated random walk. The probabilities of motion state transitions, as well as the random walk parameters, depend strongly on distance to an aphid's nearest neighbor. For large nearest neighbor distances, when an aphid is essentially isolated, its motion is ballistic with aphids moving faster, turning less, and being less likely to stop. In contrast, for short nearest neighbor distances, aphids move more slowly, turn more, and are more likely to become stationary; this behavior constitutes an aggregation mechanism. From the experimental data, we estimate the state transition probabilities and correlated random walk parameters as a function of nearest neighbor distance. With the individual-level model established, we assess whether it reproduces the macroscopic patterns of movement at the group level. To do so, we consider three distributions, namely distance to nearest neighbor, angle to nearest neighbor, and percentage of population moving at any given time. For each of these three distributions, we compare our experimental data to the output of numerical simulations of our nearest neighbor model, and of a control model in which aphids do not interact socially. Our stochastic, social nearest neighbor model reproduces salient features of the experimental data that are not captured by the control.

  15. Teaching as a fractal: from experience to model

    Directory of Open Access Journals (Sweden)

    Patricia COMPAÑ-ROSIQUE

    2015-12-01

    Full Text Available The aim of this work is to improve students’ learning by designing a teaching model that seeks to increase student motivation to acquire new knowledge. To design the model, the methodology is based on the study of the students’ opinion on several aspects we think importantly affect the quality of teaching (such as the overcrowded classrooms, time intended for the subject or type of classroom where classes are taught, and on our experience when performing several experimental activities in the classroom (for instance, peer reviews and oral presentations. Besides the feedback from the students, it is essential to rely on the experience and reflections of lecturers who have been teaching the subject several years. This way we could detect several key aspects that, in our opinion, must be considered when designing a teaching proposal: motivation, assessment, progressiveness and autonomy. As a result we have obtained a teaching model based on instructional design as well as on the principles of fractal geometry, in the sense that different levels of abstraction for the various training activities are presented and the activities are self-similar, that is, they are decomposed again and again. At each level, an activity decomposes into a lower level tasks and their corresponding evaluation. With this model the immediate feedback and the student motivation are encouraged. We are convinced that a greater motivation will suppose an increase in the student’s working time and in their performance. Although the study has been done on a subject, the results are fully generalizable to other subjects.

  16. Transitioning from Student to Teacher in the Master-Apprentice Model of Piano Pedagogy: An Exploratory Study of Challenges, Solutions, Resources, Reflections, and Suggestions for the Future

    Science.gov (United States)

    Slawsky, Melissa Maccarelli

    2011-01-01

    While many music educators learn how to teach through teacher training programs, the standard mode of transmission in which piano teachers learn to teach applied piano is through proficiency of the instrument under the guidance of a master teacher. This tacit development of pedagogical knowledge occurs through the master-apprentice model of…

  17. Development of the Play Experience Model to Enhance Desirable Qualifications of Early Childhood

    Science.gov (United States)

    Panpum, Watchara; Soonthornrojana, Wimonrat; Nakunsong, Thatsanee

    2015-01-01

    The objectives of this research were to develop the play experience model and to study the effect of usage in play experience model for enhancing the early childhood's desirable qualification. There were 3 phases of research: 1) the document and context in experience management were studied, 2) the play experience model was developed, and 3) the…

  18. Statistical Modeling Suggests that Antiandrogens in Effluents from Wastewater Treatment Works Contribute to Widespread Sexual Disruption in Fish Living in English Rivers

    Science.gov (United States)

    Jobling, Susan; Burn, Robert. W.; Thorpe, Karen; Williams, Richard; Tyler, Charles

    2009-01-01

    Background The widespread occurrence of feminized male fish downstream of some wastewater treatment works has led to substantial interest from ecologists and public health professionals. This concern stems from the view that the effects observed have a parallel in humans, and that both phenomena are caused by exposure to mixtures of contaminants that interfere with reproductive development. The evidence for a “wildlife–human connection” is, however, weak: Testicular dysgenesis syndrome, seen in human males, is most easily reproduced in rodent models by exposure to mixtures of antiandrogenic chemicals. In contrast, the accepted explanation for feminization of wild male fish is that it results mainly from exposure to steroidal estrogens originating primarily from human excretion. Objectives We sought to further explore the hypothesis that endocrine disruption in fish is multicausal, resulting from exposure to mixtures of chemicals with both estrogenic and antiandrogenic properties. Methods We used hierarchical generalized linear and generalized additive statistical modeling to explore the associations between modeled concentrations and activities of estrogenic and antiandrogenic chemicals in 30 U.K. rivers and feminized responses seen in wild fish living in these rivers. Results In addition to the estrogenic substances, antiandrogenic activity was prevalent in almost all treated sewage effluents tested. Further, the results of the modeling demonstrated that feminizing effects in wild fish could be best modeled as a function of their predicted exposure to both antiandrogens and estrogens or to antiandrogens alone. Conclusion The results provide a strong argument for a multicausal etiology of widespread feminization of wild fish in U.K. rivers involving contributions from both steroidal estrogens and xenoestrogens and from other (as yet unknown) contaminants with antiandrogenic properties. These results may add further credence to the hypothesis that endocrine

  19. Systematic Analysis of Hollow Fiber Model of Tuberculosis Experiments.

    Science.gov (United States)

    Pasipanodya, Jotam G; Nuermberger, Eric; Romero, Klaus; Hanna, Debra; Gumbo, Tawanda

    2015-08-15

    The in vitro hollow fiber system model of tuberculosis (HFS-TB), in tandem with Monte Carlo experiments, was introduced more than a decade ago. Since then, it has been used to perform a large number of tuberculosis pharmacokinetics/pharmacodynamics (PK/PD) studies that have not been subjected to systematic analysis. We performed a literature search to identify all HFS-TB experiments published between 1 January 2000 and 31 December 2012. There was no exclusion of articles by language. Bias minimization was according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Steps for reporting systematic reviews were followed. There were 22 HFS-TB studies published, of which 12 were combination therapy studies and 10 were monotherapy studies. There were 4 stand-alone Monte Carlo experiments that utilized quantitative output from the HFS-TB. All experiments reported drug pharmacokinetics, which recapitulated those encountered in humans. HFS-TB studies included log-phase growth studies under ambient air, semidormant bacteria at pH 5.8, and nonreplicating persisters at low oxygen tension of ≤ 10 parts per billion. The studies identified antibiotic exposures associated with optimal kill of Mycobacterium tuberculosis and suppression of acquired drug resistance (ADR) and informed predictions about optimal clinical doses, expected performance of standard doses and regimens in patients, and expected rates of ADR, as well as a proposal of new susceptibility breakpoints. The HFS-TB model offers the ability to perform PK/PD studies including humanlike drug exposures, to identify bactericidal and sterilizing effect rates, and to identify exposures associated with suppression of drug resistance. Because of the ability to perform repetitive sampling from the same unit over time, the HFS-TB vastly improves statistical power and facilitates the execution of time-to-event analyses and repeated event analyses, as well as dynamic system pharmacology mathematical

  20. Adhesive behaviour of gecko-inspired nanofibrillar arrays: combination of experiments and finite element modelling

    International Nuclear Information System (INIS)

    Wang Zhengzhi; Xu Yun; Gu Ping

    2012-01-01

    A polypropylene nanofibrillar array was successfully fabricated by template-assisted nanofabrication strategy. Adhesion properties of this gecko-inspired structure were studied through two parallel and independent approaches: experiments and finite element simulations. Experimental results show relatively good normal adhesion, but accompanied by high preloads. The interfacial adhesion was modelled by effective spring elements with piecewise-linear constitution. The effective elasticity of the fibre-array system was originally calculated from our measured elasticity of single nanowire. Comparisons of the experimental and simulative results reveal quantitative agreement except for some explainable deviations, which suggests the potential applicability of the present models and applied theories. (fast track communication)

  1. Modeling and Analysis of AGS (1998) Thermal Shock Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Haines, J.R.; Kim, S.H.; Taleyarkhan, R.P.

    1999-11-14

    An overview is provided on modeling and analysis of thermal shock experiments conducted during 1998 with high-energy, short-pulse energy deposition in a mercury filled container in the Alternating Gradient Synchrotron (AGS) facility at Brookhaven National Laboratory (BNL). The simulation framework utilized along with the results of simulations for pressure and strain profiles are presented. While the magnitude of penk strain predictions versus data are in reasonable agreement, the temporal variations were found to differ significantly in selected cases, indicating lack of modeling of certain physical phenomena or due to uncertainties in the experimental data gathering techniques. Key thermal-shock related issues and uncertainties are highlighted. Specific experiments conducted at BNL's AGS facility during 1998 (the subject of this paper) involved high-energy (24 GeV) proton energy deposition in the mercury target over a time frame of - 0.1s. The target consisted of an - 1 m. long cylindrical stainless steel shell with a hemispherical dome at the leading edge. It was filled with mercury at room temperature and pressure. Several optical strain gages were attached to the surface of the steel target. Figure 1 shows a schematic representation of the test vessel along with the main dimensions and positions of three optical strain gages at which meaningful data were obtained. As

  2. Modeling of Carbon Migration During JET Injection Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, J. D.; Likonen, J.; Coad, P.; Rubel, M.; Widdowson, A.; Airila, M.; Andrew, P.; Brezinsek, S.; Corrigan, G.; Esser, H. G.; Jachmich, S.; Kallenbach, A.; Kirschner, A.; Kreter, A.; Matthews, G. F.; Philipps, V.; Pitts, R. A.; Spence, J.; Stamp, M.; Wiesen, S.

    2008-10-15

    JET has performed two dedicated carbon migration experiments on the final run day of separate campaigns (2001 and 2004) using {sup 13}CH{sub 4} methane injected into repeated discharges. The EDGE2D/NIMBUS code modelled the carbon migration in both experiments. This paper describes this modelling and identifies a number of important migration pathways: (1) deposition and erosion near the injection location, (2) migration through the main chamber SOL, (3) migration through the private flux region aided by E x B drifts, and (4) neutral migration originating near the strike points. In H-Mode, type I ELMs are calculated to influence the migration by enhancing erosion during the ELM peak and increasing the long-range migration immediately following the ELM. The erosion/re-deposition cycle along the outer target leads to a multistep migration of {sup 13}C towards the separatrix which is called 'walking'. This walking created carbon neutrals at the outer strike point and led to {sup 13}C deposition in the private flux region. Although several migration pathways have been identified, quantitative analyses are hindered by experimental uncertainty in divertor leakage, and the lack of measurements at locations such as gaps and shadowed regions.

  3. Dynamical phase separation using a microfluidic device: experiments and modeling

    Science.gov (United States)

    Aymard, Benjamin; Vaes, Urbain; Radhakrishnan, Anand; Pradas, Marc; Gavriilidis, Asterios; Kalliadasis, Serafim; Complex Multiscale Systems Team

    2017-11-01

    We study the dynamical phase separation of a binary fluid by a microfluidic device both from the experimental and from the modeling points of view. The experimental device consists of a main channel (600 μm wide) leading into an array of 276 trapezoidal capillaries of 5 μm width arranged on both sides and separating the lateral channels from the main channel. Due to geometrical effects as well as wetting properties of the substrate, and under well chosen pressure boundary conditions, a multiphase flow introduced into the main channel gets separated at the capillaries. Understanding this dynamics via modeling and numerical simulation is a crucial step in designing future efficient micro-separators. We propose a diffuse-interface model, based on the classical Cahn-Hilliard-Navier-Stokes system, with a new nonlinear mobility and new wetting boundary conditions. We also propose a novel numerical method using a finite-element approach, together with an adaptive mesh refinement strategy. The complex geometry is captured using the same computer-aided design files as the ones adopted in the fabrication of the actual device. Numerical simulations reveal a very good qualitative agreement between model and experiments, demonstrating also a clear separation of phases.

  4. Modelling, simulation and experiment of the spherical flexible joint stiffness

    Directory of Open Access Journals (Sweden)

    S. Li

    2018-02-01

    Full Text Available The spherical flexible joint is extensively used in engineering. It is designed to provide flexibility in rotation while bearing vertical compression load. The linear rotational stiffness of the flexible joint is formulated. The rotational stiffness of the bonded rubber layer is related to inner radius, thickness and two edge angles. FEM is used to verify the analytical solution and analyze the stiffness. The Mooney–Rivlin, Neo Hooke and Yeoh constitutive models are used in the simulation. The experiment is taken to obtain the material coefficient and validate the analytical and FEM results. The Yeoh model can reflect the deformation trend more accurately, but the error in the nearly linear district is bigger than the Mooney–Rivlin model. The Mooney–Rivlin model can fit the test result very well and the analytical solution can also be used when the rubber deformation in the flexible joint is small. The increase of Poisson's ratio of the rubber layers will enhance the vertical compression stiffness but barely have effect on the rotational stiffness.

  5. Anomalous reactive transport in porous media: Experiments and modeling

    Science.gov (United States)

    Edery, Yaniv; Dror, Ishai; Scher, Harvey; Berkowitz, Brian

    2015-05-01

    We analyze dynamic behavior of chemically reactive species in a porous medium, subject to anomalous transport. In this context, we present transport experiments in a refraction-index-matched, three-dimensional, water-saturated porous medium. A pH indicator (Congo red) was used as either a conservative or a reactive tracer, depending on the tracer solution pH relative to that of the background solution. The porous medium consisted of an acrylic polymer material formed as spherical beads that have pH-buffering capacity. The magnitude of reaction during transport through the porous medium was related to the color change of the Congo red, via image analysis. Here, we focused on point injection of the tracer into a macroscopically uniform flow field containing water at a pH different from that of the injected tracer. The setup yielded measurements of the temporally evolving spatial (local-in-space) concentration field. Parallel experiments with the same tracer, but without reactions (no changes in pH), enabled identification of the transport itself to be anomalous (non-Fickian); this was quantified by a continuous time random walk (CTRW) formulation. A CTRW particle tracking model was then used to quantify the spatial and temporal migration of both the conservative and reactive tracer plumes. Model parameters related to the anomalous transport were determined from the conservative tracer experiments. An additional term accounting for chemical reaction was established solely from analysis of the reactant concentrations, and significantly, no other fitting parameters were required. The measurements and analysis emphasized the localized nature of reaction, caused by small-scale concentration fluctuations and preferential pathways. In addition, a threshold radius for pH-controlled reactive transport processes was defined under buffering conditions, which delineated the region in which reactions occurred rapidly.

  6. Endometriosis education in schools: A New Zealand model examining the impact of an education program in schools on early recognition of symptoms suggesting endometriosis.

    Science.gov (United States)

    Bush, Deborah; Brick, Emily; East, Michael C; Johnson, Neil

    2017-08-01

    Menstrual morbidity plays a significant role in adolescent females' lives. There are no studies to date reporting such data from menstrual health education programs in schools. The aim of our study was to report results from an audit of a menstrual health and endometriosis education program in secondary schools and observe age patterns of young women presenting for menstrual morbidity care. Audit data from education in secondary schools and audit data of patients from an Endometriosis and Pelvic Pain Coaching clinic operating in a private endometriosis specialised centre are reported. In a region of consistent delivery of the education program, student awareness of endometriosis was 32% in 2015. Overall in 2015, 13% of students experienced distressing menstrual symptoms and 27% of students sometimes or always missed school due to menstrual symptoms. Further, in one region of consistent delivery of the menstrual health education program, data show an increase in younger patients attending for specialised endometriosis care. There is strong suggestive evidence that consistent delivery of a menstrual health education program in schools increases adolescent student awareness of endometriosis. In addition, there is suggestive evidence that in a geographical area of consistent delivery of the program, a shift in earlier presentation of young women to a specialised health service is observed. © 2017 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

  7. When the rule becomes the exception. no evidence of gene flow between two Zerynthia cryptic butterflies suggests the emergence of a new model group.

    Science.gov (United States)

    Zinetti, Francesca; Dapporto, Leonardo; Vovlas, Alessio; Chelazzi, Guido; Bonelli, Simona; Balletto, Emilio; Ciofi, Claudio

    2013-01-01

    There is increasing evidence that most parapatric cryptic/sister taxa are reproductively compatible across their areas of contact. Consequently, the biological species concept, which assumes absence of interbreeding, is becoming a not so effective criterion in evolutionary ecology. Nevertheless, the few parapatric sister taxa showing complete reproductive barriers represent interesting models to study speciation processes and the evolution of reproductive isolation. In this study, we examined contact populations in northwestern Italy of two butterfly species, Zerynthia polyxena and Z. cassandra, characterized by different genitalic morphotypes. We studied levels of divergence among 21 populations distributed from Sicily to France using three genetic markers (the mitochondrial COI and ND1 genes and the nuclear wingless gene) and genitalic geometric morphometrics. Moreover, we performed species distribution modelling to estimate different climatic requirements of Z. polyxena and Z. cassandra. We projected climatic data into glacial maximum scenarios in order to verify if and to which extent glacial cycles could have contributed to speciation processes. Genetic and morphometric analyses identified two main groups. All specimens showed a concordant pattern of diversification, including those individuals sampled in the contact area. Haplotype distribution and climatic models showed that during glacial maxima both species experienced a strong range contraction and presumably remained separated into different microrefugia in southern France, in the Italian Peninsula and on the islands of Elba and Sicily. Long term separation was probably favoured by reduced dispersal ability and high phylopatry, while genitalic diversification probably favoured interbreeding avoidance. Conversely, the aposematic wing pattern remained almost identical. We compared our results with those obtained in other species and concluded that Z. polyxena and Z. cassandra represent a valuable model in

  8. A suggested syllabus model for a course in developing reading skills with special reference to the ELT Department at Gazi University

    OpenAIRE

    Tikence, Mevlüt

    1991-01-01

    Ankara : The Institute of Economics and Social Sciences of Bilkent Univ., 1991. Thesis (Master's) -- Bilkent University, 1991. Includes bibliographical references leaves 63-64. The focus of this study is the development of a model syllabus for an English for Specific Purposes (ESP) reading course taught to first year students of the Gazi University ELT Department. First, the general background of ESP, problems of the reading course at Gazi and the limitations of the st...

  9. Classification of hadith into positive suggestion, negative suggestion, and information

    Science.gov (United States)

    Faraby, Said Al; Riviera Rachmawati Jasin, Eliza; Kusumaningrum, Andina; Adiwijaya

    2018-03-01

    As one of the Muslim life guidelines, based on the meaning of its sentence(s), a hadith can be viewed as a suggestion for doing something, or a suggestion for not doing something, or just information without any suggestion. In this paper, we tried to classify the Bahasa translation of hadith into the three categories using machine learning approach. We tried stemming and stopword removal in preprocessing, and TF-IDF of unigram, bigram, and trigram as the extracted features. As the classifier, we compared between SVM and Neural Network. Since the categories are new, so in order to compare the results of the previous pipelines, we created a baseline classifier using simple rule-based string matching technique. The rule-based algorithm conditions on the occurrence of words such as “janganlah, sholatlah, and so on” to determine the category. The baseline method achieved F1-Score of 0.69, while the best F1-Score from the machine learning approach was 0.88, and it was produced by SVM model with the linear kernel.

  10. Constructing Experience: Event Models from Perception to Action.

    Science.gov (United States)

    Richmond, Lauren L; Zacks, Jeffrey M

    2017-12-01

    Mental representations of everyday experience are rich, structured, and multimodal. In this article we consider the adaptive pressures that led to human construction of such representations, arguing that structured event representations enable cognitive systems to more effectively predict the trajectory of naturalistic everyday activity. We propose an account of how cortical systems and the hippocampus (HPC) interact to construct, maintain, and update event representations. This analysis throws light on recent research on story comprehension, event segmentation, episodic memory, and action planning. It also suggests how the growing science base can be deployed to diagnose impairments in event perception and memory, and to improve memory for everyday events. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. The Context-Dependency of the Experience of Auditory Succession and Prospects for Embodying Philosophical Models of Temporal Experience

    OpenAIRE

    Maria Kon

    2015-01-01

    Recent philosophical work on temporal experience offers generic models that are often assumed to apply to all sensory modalities. I show that the models serve as broad frameworks in which different aspects of cognitive science can be slotted and, thus, are beneficial to furthering research programs in embodied music cognition. Here I discuss a particular feature of temporal experience that plays a key role in such philosophical work: a distinction between the experience of succession and the ...

  12. Systems-Oriented Workplace Learning Experiences for Early Learners: Three Models.

    Science.gov (United States)

    O'Brien, Bridget C; Bachhuber, Melissa R; Teherani, Arianne; Iker, Theresa M; Batt, Joanne; O'Sullivan, Patricia S

    2017-05-01

    Early workplace learning experiences may be effective for learning systems-based practice. This study explores systems-oriented workplace learning experiences (SOWLEs) for early learners to suggest a framework for their development. The authors used a two-phase qualitative case study design. In Phase 1 (spring 2014), they prepared case write-ups based on transcribed interviews from 10 SOWLE leaders at the authors' institution and, through comparative analysis of cases, identified three SOWLE models. In Phase 2 (summer 2014), studying seven 8-week SOWLE pilots, the authors used interview and observational data collected from the seven participating medical students, two pharmacy students, and site leaders to construct case write-ups of each pilot and to verify and elaborate the models. In Model 1, students performed specific patient care activities that addressed a system gap. Some site leaders helped students connect the activities to larger systems problems and potential improvements. In Model 2, students participated in predetermined systems improvement (SI) projects, gaining experience in the improvement process. Site leaders had experience in SI and often had significant roles in the projects. In Model 3, students worked with key stakeholders to develop a project and conduct a small test of change. They experienced most elements of an improvement cycle. Site leaders often had experience with SI and knew how to guide and support students' learning. Each model could offer systems-oriented learning opportunities provided that key elements are in place including site leaders facile in SI concepts and able to guide students in SOWLE activities.

  13. Cryo-EM structure of Mcm2-7 double hexamer on DNA suggests a lagging-strand DNA extrusion model

    Science.gov (United States)

    Noguchi, Yasunori; Yuan, Zuanning; Bai, Lin; Schneider, Sarah; Zhao, Gongpu; Li, Huilin

    2017-01-01

    During replication initiation, the core component of the helicase—the Mcm2-7 hexamer—is loaded on origin DNA as a double hexamer (DH). The two ring-shaped hexamers are staggered, leading to a kinked axial channel. How the origin DNA interacts with the axial channel is not understood, but the interaction could provide key insights into Mcm2-7 function and regulation. Here, we report the cryo-EM structure of the Mcm2-7 DH on dsDNA and show that the DNA is zigzagged inside the central channel. Several of the Mcm subunit DNA-binding loops, such as the oligosaccharide–oligonucleotide loops, helix 2 insertion loops, and presensor 1 (PS1) loops, are well defined, and many of them interact extensively with the DNA. The PS1 loops of Mcm 3, 4, 6, and 7, but not 2 and 5, engage the lagging strand with an approximate step size of one base per subunit. Staggered coupling of the two opposing hexamers positions the DNA right in front of the two Mcm2–Mcm5 gates, with each strand being pressed against one gate. The architecture suggests that lagging-strand extrusion initiates in the middle of the DH that is composed of the zinc finger domains of both hexamers. To convert the Mcm2-7 DH structure into the Mcm2-7 hexamer structure found in the active helicase, the N-tier ring of the Mcm2-7 hexamer in the DH-dsDNA needs to tilt and shift laterally. We suggest that these N-tier ring movements cause the DNA strand separation and lagging-strand extrusion. PMID:29078375

  14. Experiments to Populate and Validate a Processing Model for Polyurethane Foam: Additional Data for Structural Foams

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Rekha R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Celina, Mathias C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Giron, Nicholas Henry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Long, Kevin Nicholas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Russick, Edward M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    We are developing computational models to help understand manufacturing processes, final properties and aging of structural foam, polyurethane PMDI. Th e resulting model predictions of density and cure gradients from the manufacturing process will be used as input to foam heat transfer and mechanical models. BKC 44306 PMDI-10 and BKC 44307 PMDI-18 are the most prevalent foams used in structural parts. Experiments needed to parameterize models of the reaction kinetics and the equations of motion during the foam blowing stages were described for BKC 44306 PMDI-10 in the first of this report series (Mondy et al. 2014). BKC 44307 PMDI-18 is a new foam that will be used to make relatively dense structural supports via over packing. It uses a different catalyst than those in the BKC 44306 family of foams; hence, we expect that the reaction kineti cs models must be modified. Here we detail the experiments needed to characteriz e the reaction kinetics of BKC 44307 PMDI-18 and suggest parameters for the model based on these experiments. In additi on, the second part of this report describes data taken to provide input to the preliminary nonlinear visco elastic structural response model developed for BKC 44306 PMDI-10 foam. We show that the standard cu re schedule used by KCP does not fully cure the material, and, upon temperature elevation above 150°C, oxidation or decomposition reactions occur that alter the composition of the foam. These findings suggest that achieving a fully cured foam part with this formulation may be not be possible through therma l curing. As such, visco elastic characterization procedures developed for curing thermosets can provide only approximate material properties, since the state of the material continuously evolves during tests.

  15. Bayesian model calibration of computational models in velocimetry diagnosed dynamic compression experiments.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Justin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hund, Lauren [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    Dynamic compression experiments are being performed on complicated materials using increasingly complex drivers. The data produced in these experiments are beginning to reach a regime where traditional analysis techniques break down; requiring the solution of an inverse problem. A common measurement in dynamic experiments is an interface velocity as a function of time, and often this functional output can be simulated using a hydrodynamics code. Bayesian model calibration is a statistical framework to estimate inputs into a computational model in the presence of multiple uncertainties, making it well suited to measurements of this type. In this article, we apply Bayesian model calibration to high pressure (250 GPa) ramp compression measurements in tantalum. We address several issues speci c to this calibration including the functional nature of the output as well as parameter and model discrepancy identi ability. Speci cally, we propose scaling the likelihood function by an e ective sample size rather than modeling the autocorrelation function to accommodate the functional output and propose sensitivity analyses using the notion of `modularization' to assess the impact of experiment-speci c nuisance input parameters on estimates of material properties. We conclude that the proposed Bayesian model calibration procedure results in simple, fast, and valid inferences on the equation of state parameters for tantalum.

  16. Optimum coagulant forecasting by modeling jar test experiments using ANNs

    Science.gov (United States)

    Haghiri, Sadaf; Daghighi, Amin; Moharramzadeh, Sina

    2018-01-01

    Currently, the proper utilization of water treatment plants and optimizing their use is of particular importance. Coagulation and flocculation in water treatment are the common ways through which the use of coagulants leads to instability of particles and the formation of larger and heavier particles, resulting in improvement of sedimentation and filtration processes. Determination of the optimum dose of such a coagulant is of particular significance. A high dose, in addition to adding costs, can cause the sediment to remain in the filtrate, a dangerous condition according to the standards, while a sub-adequate dose of coagulants can result in the reducing the required quality and acceptable performance of the coagulation process. Although jar tests are used for testing coagulants, such experiments face many constraints with respect to evaluating the results produced by sudden changes in input water because of their significant costs, long time requirements, and complex relationships among the many factors (turbidity, temperature, pH, alkalinity, etc.) that can influence the efficiency of coagulant and test results. Modeling can be used to overcome these limitations; in this research study, an artificial neural network (ANN) multi-layer perceptron (MLP) with one hidden layer has been used for modeling the jar test to determine the dosage level of used coagulant in water treatment processes. The data contained in this research have been obtained from the drinking water treatment plant located in Ardabil province in Iran. To evaluate the performance of the model, the mean squared error (MSE) and correlation coefficient (R2) parameters have been used. The obtained values are within an acceptable range that demonstrates the high accuracy of the models with respect to the estimation of water-quality characteristics and the optimal dosages of coagulants; so using these models will allow operators to not only reduce costs and time taken to perform experimental jar tests

  17. Microcosm Experiments and Modeling of Microbial Movement Under Unsaturated Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Brockman, F.J.; Kapadia, N.; Williams, G.; Rockhold, M.

    2006-04-05

    Colonization of bacteria in porous media has been studied primarily in saturated systems. In this study we examine how microbial colonization in unsaturated porous media is controlled by water content and particle size. This is important for understanding the feasibility and success of bioremediation via nutrient delivery when contaminant degraders are at low densities and when total microbial populations are sparse and spatially discontinuous. The study design used 4 different sand sizes, each at 4 different water contents; experiments were run with and without acetate as the sole carbon source. All experiments were run in duplicate columns and used the motile organism Pseudomonas stutzeri strain KC, a carbon tetrachloride degrader. At a given sand size, bacteria traveled further with increasing volumetric water content. At a given volumetric water content, bacteria generally traveled further with increasing sand size. Water redistribution, solute transport, gas diffusion, and bacterial colonization dynamics were simulated using a numerical finite-difference model. Solute and bacterial transport were modeled using advection-dispersion equations, with reaction rate source/sink terms to account for bacterial growth and substrate utilization, represented using dual Monod-type kinetics. Oxygen transport and diffusion was modeled accounting for equilibrium partitioning between the aqueous and gas phases. The movement of bacteria in the aqueous phase was modeled using a linear impedance model in which the term D{sub m} is a coefficient, as used by Barton and Ford (1995), representing random motility. The unsaturated random motility coefficients we obtained (1.4 x 10{sup -6} to 2.8 x 10{sup -5} cm{sup 2}/sec) are in the same range as those found by others for saturated systems (3.5 x 10{sup -6} to 3.5 x 10{sup -5} cm{sup 2}/sec). The results show that some bacteria can rapidly migrate in well sorted unsaturated sands (and perhaps in relatively high porosity, poorly

  18. Modelling of a diffusion-sorption experiment on sandstone

    International Nuclear Information System (INIS)

    Smith, P.A.

    1989-11-01

    The results of a diffusion-sorption experiment on a sample of Darley Dale sandstone, using simulated groundwater spiked with a mixture of 125 I, 85 Sr and 137 Cs, are modelled by a one-dimensional porous medium approach in which sorption is described by Freundlich isotherms. The governing equations are solved analytically for the special case of a linear isotherm, and numerically using the computer code RANCHDIFF for non-linear isotherms. A set of time-dependent, ordinary differential equations is obtained using the Lagrange interpolation technique and integrated by Gear's variable order predictor-corrector method. It is shown that the sorption behaviour of 85 Sr can be modelled successfully by a linear isotherm, using a sorption parameter consistent with batch-sorption tests. The behaviour of 137 Cs may be modelled by a non-linear isotherm, but the amount of 137 Cs sorbed is less than that anticipated from batch-sorption tests. 125 I is assumed to be non-sorbing and is used to determine the porosity of the sandstone. (author) 10 figs., 4 tabs., 6 refs

  19. Edge effect modeling and experiments on active lap processing.

    Science.gov (United States)

    Liu, Haitao; Wu, Fan; Zeng, Zhige; Fan, Bin; Wan, Yongjian

    2014-05-05

    Edge effect is regarded as one of the most difficult technical issues for fabricating large primary mirrors, especially for large polishing tools. Computer controlled active lap (CCAL) uses a large size pad (e.g., 1/3 to 1/5 workpiece diameters) to grind and polish the primary mirror. Edge effect also exists in the CCAL process in our previous fabrication. In this paper the material removal rules when edge effects happen (i.e. edge tool influence functions (TIFs)) are obtained through experiments, which are carried out on a Φ1090-mm circular flat mirror with a 375-mm-diameter lap. Two methods are proposed to model the edge TIFs for CCAL. One is adopting the pressure distribution which is calculated based on the finite element analysis method. The other is building up a parametric equivalent pressure model to fit the removed material curve directly. Experimental results show that these two methods both effectively model the edge TIF of CCAL.

  20. Gas transfer under breaking waves: experiments and an improved vorticity-based model

    Directory of Open Access Journals (Sweden)

    V. K. Tsoukala

    2008-07-01

    Full Text Available In the present paper a modified vorticity-based model for gas transfer under breaking waves in the absence of significant wind forcing is presented. A theoretically valid and practically applicable mathematical expression is suggested for the assessment of the oxygen transfer coefficient in the area of wave-breaking. The proposed model is based on the theory of surface renewal that expresses the oxygen transfer coefficient as a function of both the wave vorticity and the Reynolds wave number for breaking waves. Experimental data were collected in wave flumes of various scales: a small-scale experiments were carried out using both a sloping beach and a rubble-mound breakwater in the wave flume of the Laboratory of Harbor Works, NTUA, Greece; b large-scale experiments were carried out with a sloping beach in the wind-wave flume of Delft Hydraulics, the Netherlands, and with a three-layer rubble mound breakwater in the Schneideberg Wave Flume of the Franzius Institute, University of Hannover, Germany. The experimental data acquired from both the small- and large-scale experiments were in good agreement with the proposed model. Although the apparent transfer coefficients from the large-scale experiments were lower than those determined from the small-scale experiments, the actual oxygen transfer coefficients, as calculated using a discretized form of the transport equation, are in the same order of magnitude for both the small- and large-scale experiments. The validity of the proposed model is compared to experimental results from other researchers. Although the results are encouraging, additional research is needed, to incorporate the influence of bubble mediated gas exchange, before these results are used for an environmental friendly design of harbor works, or for projects involving waste disposal at sea.

  1. Crystal structure of Mycobacterium tuberculosis ClpP1P2 suggests a model for peptidase activation by AAA+ partner binding and substrate delivery.

    Science.gov (United States)

    Schmitz, Karl R; Carney, Daniel W; Sello, Jason K; Sauer, Robert T

    2014-10-28

    Caseinolytic peptidase P (ClpP), a double-ring peptidase with 14 subunits, collaborates with ATPases associated with diverse activities (AAA+) partners to execute ATP-dependent protein degradation. Although many ClpP enzymes self-assemble into catalytically active homo-tetradecamers able to cleave small peptides, the Mycobacterium tuberculosis enzyme consists of discrete ClpP1 and ClpP2 heptamers that require a AAA+ partner and protein-substrate delivery or a peptide agonist to stabilize assembly of the active tetradecamer. Here, we show that cyclic acyldepsipeptides (ADEPs) and agonist peptides synergistically activate ClpP1P2 by mimicking AAA+ partners and substrates, respectively, and determine the structure of the activated complex. Our studies establish the basis of heteromeric ClpP1P2 assembly and function, reveal tight coupling between the conformations of each ring, show that ADEPs bind only to one ring but appear to open the axial pores of both rings, provide a foundation for rational drug development, and suggest strategies for studying the roles of individual ClpP1 and ClpP2 rings in Clp-family proteolysis.

  2. Complete mtDNA sequences of two millipedes suggest a new model for mitochondrial gene rearrangements: Duplication and non-random loss

    Energy Technology Data Exchange (ETDEWEB)

    Lavrov, Dennis V.; Boore, Jeffrey L.; Brown, Wesley M.

    2001-11-08

    We determined the complete mtDNA sequences of the millipedes Narceus annularus and Thyropygus sp. (Arthropoda: Diplopoda) and identified in both genomes all 37 genes typical for metazoan mtDNA. The arrangement of these genes is identical in the two millipedes, but differs from that inferred to be ancestral for arthropods by the location of four genes/gene clusters. This novel gene arrangement is unusual for animal mtDNA, in that genes with opposite transcriptional polarities are clustered in the genome and the two clusters are separated by two non-coding regions. The only exception to this pattern is the gene for cysteine tRNA, which is located in the part of the genome that otherwise contains all genes with the opposite transcriptional polarity. We suggest that a mechanism involving complete mtDNA duplication followed by the loss of genes, predetermined by their transcriptional polarity and location in the genome, could generate this gene arrangement from the one ancestral for arthropods. The proposed mechanism has important implications for phylogenetic inferences that are drawn on the basis of gene arrangement comparisons.

  3. Auditory function in the Tc1 mouse model of down syndrome suggests a limited region of human chromosome 21 involved in otitis media.

    Science.gov (United States)

    Kuhn, Stephanie; Ingham, Neil; Pearson, Selina; Gribble, Susan M; Clayton, Stephen; Steel, Karen P; Marcotti, Walter

    2012-01-01

    Down syndrome is one of the most common congenital disorders leading to a wide range of health problems in humans, including frequent otitis media. The Tc1 mouse carries a significant part of human chromosome 21 (Hsa21) in addition to the full set of mouse chromosomes and shares many phenotypes observed in humans affected by Down syndrome with trisomy of chromosome 21. However, it is unknown whether Tc1 mice exhibit a hearing phenotype and might thus represent a good model for understanding the hearing loss that is common in Down syndrome. In this study we carried out a structural and functional assessment of hearing in Tc1 mice. Auditory brainstem response (ABR) measurements in Tc1 mice showed normal thresholds compared to littermate controls and ABR waveform latencies and amplitudes were equivalent to controls. The gross anatomy of the middle and inner ears was also similar between Tc1 and control mice. The physiological properties of cochlear sensory receptors (inner and outer hair cells: IHCs and OHCs) were investigated using single-cell patch clamp recordings from the acutely dissected cochleae. Adult Tc1 IHCs exhibited normal resting membrane potentials and expressed all K(+) currents characteristic of control hair cells. However, the size of the large conductance (BK) Ca(2+) activated K(+) current (I(K,f)), which enables rapid voltage responses essential for accurate sound encoding, was increased in Tc1 IHCs. All physiological properties investigated in OHCs were indistinguishable between the two genotypes. The normal functional hearing and the gross structural anatomy of the middle and inner ears in the Tc1 mouse contrast to that observed in the Ts65Dn model of Down syndrome which shows otitis media. Genes that are trisomic in Ts65Dn but disomic in Tc1 may predispose to otitis media when an additional copy is active.

  4. Primordial germ cell development in the marmoset monkey as revealed by pluripotency factor expression: suggestion of a novel model of embryonic germ cell translocation.

    Science.gov (United States)

    Aeckerle, N; Drummer, C; Debowski, K; Viebahn, C; Behr, R

    2015-01-01

    Primordial germ cells (PGCs) are the embryonic progenitors of sperm and egg cells. Mammalian PGCs are thought to actively migrate from the yolk sac endoderm over long distances across the embryo to reach the somatic genital ridges. The general principles of mammalian PGC development were discovered in mice. In contrast, little is known about PGC development in primates due to extremely limited access to primate embryos. Here, we analyzed 12 well preserved marmoset monkey (Callithrix jacchus) embryos covering the phase from PGC emergence in the endoderm to the formation of the sexually differentiated gonad (embryonic day (E) 50 to E95). We show using immunohistochemistry that the pluripotency factors OCT4A and NANOG specifically mark PGCs throughout the period studied. In contrast, SALL4 and LIN28 were first expressed ubiquitously and only later down-regulated in somatic tissues. We further show, for the first time, that PGCs are located in the endoderm in E50 embryos in close spatial proximity to the prospective genital ridge, making a long-range migration of PGCs dispensable. At E65, PGCs are already present in the primitive gonad, while significantly later embryonic stages still exhibit PGCs at their original endodermal site, revealing a wide spatio-temporal window of PGC distribution. Our findings challenge the 'dogma' of active long-range PGC migration from the endoderm to the gonads. We therefore favor an alternative model based primarily on passive translocation of PGCs from the mesenchyme that surrounds the gut to the prospective gonad through the intercalar expansion of mesenchymal tissue which contains the PGCs. In summary, we (i) show differential pluripotency factor expression during primate embryo development and (ii) provide a schematic model for embryonic PGC translocation. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology.

  5. Auditory function in the Tc1 mouse model of down syndrome suggests a limited region of human chromosome 21 involved in otitis media.

    Directory of Open Access Journals (Sweden)

    Stephanie Kuhn

    Full Text Available Down syndrome is one of the most common congenital disorders leading to a wide range of health problems in humans, including frequent otitis media. The Tc1 mouse carries a significant part of human chromosome 21 (Hsa21 in addition to the full set of mouse chromosomes and shares many phenotypes observed in humans affected by Down syndrome with trisomy of chromosome 21. However, it is unknown whether Tc1 mice exhibit a hearing phenotype and might thus represent a good model for understanding the hearing loss that is common in Down syndrome. In this study we carried out a structural and functional assessment of hearing in Tc1 mice. Auditory brainstem response (ABR measurements in Tc1 mice showed normal thresholds compared to littermate controls and ABR waveform latencies and amplitudes were equivalent to controls. The gross anatomy of the middle and inner ears was also similar between Tc1 and control mice. The physiological properties of cochlear sensory receptors (inner and outer hair cells: IHCs and OHCs were investigated using single-cell patch clamp recordings from the acutely dissected cochleae. Adult Tc1 IHCs exhibited normal resting membrane potentials and expressed all K(+ currents characteristic of control hair cells. However, the size of the large conductance (BK Ca(2+ activated K(+ current (I(K,f, which enables rapid voltage responses essential for accurate sound encoding, was increased in Tc1 IHCs. All physiological properties investigated in OHCs were indistinguishable between the two genotypes. The normal functional hearing and the gross structural anatomy of the middle and inner ears in the Tc1 mouse contrast to that observed in the Ts65Dn model of Down syndrome which shows otitis media. Genes that are trisomic in Ts65Dn but disomic in Tc1 may predispose to otitis media when an additional copy is active.

  6. Failed oceanic transform models: experience of shaking the tree

    Science.gov (United States)

    Gerya, Taras

    2017-04-01

    In geodynamics, numerical modeling is often used as a trial-and-error tool, which does not necessarily requires full understanding or even a correct concept for a modeled phenomenon. Paradoxically, in order to understand an enigmatic process one should simply try to model it based on some initial assumptions, which must not even be correct… The reason is that our intuition is not always well "calibrated" for understanding of geodynamic phenomena, which develop on space- and timescales that are very different from our everyday experience. We often have much better ideas about physical laws governing geodynamic processes than on how these laws should interact on geological space- and timescales. From this prospective, numerical models, in which these physical laws are self-consistently implemented, can gradually calibrate our intuition by exploring what scenarios are physically sensible and what are not. I personally went through this painful learning path many times and one noteworthy example was my 3D numerical modeling of oceanic transform faults. As I understand in retrospective, my initial literature-inspired concept of how and why transform faults form and evolve was thermomechanically inconsistent and based on two main assumptions (btw. both were incorrect!): (1) oceanic transforms are directly inherited from the continental rifting and breakup stages and (2) they represent plate fragmentation structures having peculiar extension-parallel orientation due to the stress rotation caused by thermal contraction of the oceanic lithosphere. During one year (!) of high-resolution thermomechanical numerical experiments exploring various physics (including very computationally demanding thermal contraction) I systematically observed how my initially prescribed extension-parallel weak transform faults connecting ridge segments rotated away from their original orientation and get converted into oblique ridge sections… This was really an epic failure! However, at the

  7. Model analysis of the colloid and radionuclide retardation experiment at the Grimsel Test Site.

    Science.gov (United States)

    Kurosawa, Susumu; James, Scott C; Yui, Mikazu; Ibaraki, Motomu

    2006-06-01

    The colloid and radionuclide retardation experiments performed at NAGRA's Grimsel Test Site in Switzerland are part of an international collaboration program designed to collect in situ data on the impacts of colloids on radionuclide transport. In this work, breakthrough behaviors of trivalent americium (i.e., 241Am and 243Am) both in the absence and presence of bentonite colloids are analyzed with COLFRAC--a code that models colloid-facilitated solute transport in discretely-fractured, porous media. Model fits to the experimental results indicate that Am sorbed onto mobile colloids, which enhance Am transport relative to a non-sorbing tracer, 131I. Modelling results suggest that Am is kinetically sorbed onto both naturally occurring and exogenous bentonite colloids. Results also indicate that desorption of Am from colloids is slow with respect to the duration of the experiment. In addition, early colloid breakthrough compared to a conservative tracer suggests the effects of hydrodynamic chromatography. Overall, Am breakthrough curves suggest enhanced mobility due to co-transport with both naturally occurring and bentonite colloids.

  8. A Nonlinear Ship Manoeuvering Model: Identification and adaptive control with experiments for a model ship

    Directory of Open Access Journals (Sweden)

    Roger Skjetne

    2004-01-01

    Full Text Available Complete nonlinear dynamic manoeuvering models of ships, with numerical values, are hard to find in the literature. This paper presents a modeling, identification, and control design where the objective is to manoeuver a ship along desired paths at different velocities. Material from a variety of references have been used to describe the ship model, its difficulties, limitations, and possible simplifications for the purpose of automatic control design. The numerical values of the parameters in the model is identified in towing tests and adaptive manoeuvering experiments for a small ship in a marine control laboratory.

  9. Electrostatic Model Applied to ISS Charged Water Droplet Experiment

    Science.gov (United States)

    Stevenson, Daan; Schaub, Hanspeter; Pettit, Donald R.

    2015-01-01

    The electrostatic force can be used to create novel relative motion between charged bodies if it can be isolated from the stronger gravitational and dissipative forces. Recently, Coulomb orbital motion was demonstrated on the International Space Station by releasing charged water droplets in the vicinity of a charged knitting needle. In this investigation, the Multi-Sphere Method, an electrostatic model developed to study active spacecraft position control by Coulomb charging, is used to simulate the complex orbital motion of the droplets. When atmospheric drag is introduced, the simulated motion closely mimics that seen in the video footage of the experiment. The electrostatic force's inverse dependency on separation distance near the center of the needle lends itself to analytic predictions of the radial motion.

  10. Experiments and Modeling in Support of Generic Salt Repository Science

    Energy Technology Data Exchange (ETDEWEB)

    Bourret, Suzanne Michelle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stauffer, Philip H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Weaver, Douglas James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Caporuscio, Florie Andre [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Otto, Shawn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Boukhalfa, Hakim [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jordan, Amy B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chu, Shaoping [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zyvoloski, George Anthony [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Johnson, Peter Jacob [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-19

    Salt is an attractive material for the disposition of heat generating nuclear waste (HGNW) because of its self-sealing, viscoplastic, and reconsolidation properties (Hansen and Leigh, 2012). The rate at which salt consolidates and the properties of the consolidated salt depend on the composition of the salt, including its content in accessory minerals and moisture, and the temperature under which consolidation occurs. Physicochemical processes, such as mineral hydration/dehydration salt dissolution and precipitation play a significant role in defining the rate of salt structure changes. Understanding the behavior of these complex processes is paramount when considering safe design for disposal of heat-generating nuclear waste (HGNW) in salt formations, so experimentation and modeling is underway to characterize these processes. This report presents experiments and simulations in support of the DOE-NE Used Fuel Disposition Campaign (UFDC) for development of drift-scale, in-situ field testing of HGNW in salt formations.

  11. Life Course Pathways From Adverse Childhood Experiences to Adult Physical Health: A Structural Equation Model.

    Science.gov (United States)

    Nurius, Paula S; Fleming, Christopher M; Brindle, Eleanor

    2017-08-01

    This study examines pathways from adverse childhood experiences (ACEs) to physical health, directly and indirectly through lower income, health risk behaviors, social support, and adult adversity within a theoretical framework postulating stress proliferative and biological trajectories of cumulative adversity. Data were obtained from 12,549 adult respondents of a state Behavioral Risk Factor Surveillance System survey. Multigroup structural equation modeling elucidated pathways differentiated by sex and age (older/younger than 45). Good model fit was achieved in each test, indicating consistency with stress theorizing that ACEs significantly contribute to poorer physical health through direct and mediated paths. Younger adults evidenced direct ACE pathway to poor health suggesting early biological erosion, whereas paucity of social support among older adults was directly associated. Findings indicate that stress process roles in eroding physical health and experience of wellness. Addressing early adversity is an important strategy toward reducing preventable health problems.

  12. ITER transient consequences for material damage: modelling versus experiments

    Science.gov (United States)

    Bazylev, B.; Janeschitz, G.; Landman, I.; Pestchanyi, S.; Loarte, A.; Federici, G.; Merola, M.; Linke, J.; Zhitlukhin, A.; Podkovyrov, V.; Klimov, N.; Safronov, V.

    2007-03-01

    Carbon-fibre composite (CFC) and tungsten macrobrush armours are foreseen as PFC for the ITER divertor. In ITER the main mechanisms of metallic armour damage remain surface melting and melt motion erosion. In the case of CFC armour, due to rather different heat conductivities of CFC fibres a noticeable erosion of the PAN bundles may occur at rather small heat loads. Experiments carried out in the plasma gun facilities QSPA-T for the ITER like edge localized mode (ELM) heat load also demonstrated significant erosion of the frontal and lateral brush edges. Numerical simulations of the CFC and tungsten (W) macrobrush target damage accounting for the heat loads at the face and lateral brush edges were carried out for QSPA-T conditions using the three-dimensional (3D) code PHEMOBRID. The modelling results of CFC damage are in a good qualitative and quantitative agreement with the experiments. Estimation of the droplet splashing caused by the Kelvin-Helmholtz (KH) instability was performed.

  13. How Magnus Bends the Flying Ball - Experimenting and Modeling

    Science.gov (United States)

    Timková, V.; Ješková, Z.

    2017-02-01

    Students are well aware of the effect of the deflection of sports balls when they have been given a spin. A volleyball, tennis, or table tennis ball served with topspin results in an additional downward force that makes the ball difficult to catch and return. In soccer, the effect of sidespin causes the ball to curve unexpectedly sideways, resulting in a so-called banana kick that can confuse the goalkeeper. These surprising effects attract students' attention such that the motion of sports balls can be used to capture the interest of students towards the physics behind it. However, to study and analyze the motion of a real ball kicked in a playfield is not an easy task. Instead of the large-scale full-size sports ball motion, there can be designed and studied simpler experiments that can be carried out in the classroom. Moreover, digital technologies that are available at schools enable students to collect data from the experiment easily in a reasonable time. The mathematical model based on the analysis of forces acting on the ball flying in the air can be used to simulate the motion in order to understand the basic physical principles of the motion so that the best correspondence may be found.

  14. ITER transient consequences for material damage: modelling versus experiments

    International Nuclear Information System (INIS)

    Bazylev, B; Janeschitz, G; Landman, I; Pestchanyi, S; Loarte, A; Federici, G; Merola, M; Linke, J; Zhitlukhin, A; Podkovyrov, V; Klimov, N; Safronov, V

    2007-01-01

    Carbon-fibre composite (CFC) and tungsten macrobrush armours are foreseen as PFC for the ITER divertor. In ITER the main mechanisms of metallic armour damage remain surface melting and melt motion erosion. In the case of CFC armour, due to rather different heat conductivities of CFC fibres a noticeable erosion of the PAN bundles may occur at rather small heat loads. Experiments carried out in the plasma gun facilities QSPA-T for the ITER like edge localized mode (ELM) heat load also demonstrated significant erosion of the frontal and lateral brush edges. Numerical simulations of the CFC and tungsten (W) macrobrush target damage accounting for the heat loads at the face and lateral brush edges were carried out for QSPA-T conditions using the three-dimensional (3D) code PHEMOBRID. The modelling results of CFC damage are in a good qualitative and quantitative agreement with the experiments. Estimation of the droplet splashing caused by the Kelvin-Helmholtz (KH) instability was performed

  15. Decision dynamics of departure times: Experiments and modeling

    Science.gov (United States)

    Sun, Xiaoyan; Han, Xiao; Bao, Jian-Zhang; Jiang, Rui; Jia, Bin; Yan, Xiaoyong; Zhang, Boyu; Wang, Wen-Xu; Gao, Zi-You

    2017-10-01

    A fundamental problem in traffic science is to understand user-choice behaviors that account for the emergence of complex traffic phenomena. Despite much effort devoted to theoretically exploring departure time choice behaviors, relatively large-scale and systematic experimental tests of theoretical predictions are still lacking. In this paper, we aim to offer a more comprehensive understanding of departure time choice behaviors in terms of a series of laboratory experiments under different traffic conditions and feedback information provided to commuters. In the experiment, the number of recruited players is much larger than the number of choices to better mimic the real scenario, in which a large number of commuters will depart simultaneously in a relatively small time window. Sufficient numbers of rounds are conducted to ensure the convergence of collective behavior. Experimental results demonstrate that collective behavior is close to the user equilibrium, regardless of different scales and traffic conditions. Moreover, the amount of feedback information has a negligible influence on collective behavior but has a relatively stronger effect on individual choice behaviors. Reinforcement learning and Fermi learning models are built to reproduce the experimental results and uncover the underlying mechanism. Simulation results are in good agreement with the experimentally observed collective behaviors.

  16. Modeling of arylamide helix mimetics in the p53 peptide binding site of hDM2 suggests parallel and anti-parallel conformations are both stable.

    Directory of Open Access Journals (Sweden)

    Jonathan C Fuller

    Full Text Available The design of novel α-helix mimetic inhibitors of protein-protein interactions is of interest to pharmaceuticals and chemical genetics researchers as these inhibitors provide a chemical scaffold presenting side chains in the same geometry as an α-helix. This conformational arrangement allows the design of high affinity inhibitors mimicking known peptide sequences binding specific protein substrates. We show that GAFF and AutoDock potentials do not properly capture the conformational preferences of α-helix mimetics based on arylamide oligomers and identify alternate parameters matching solution NMR data and suitable for molecular dynamics simulation of arylamide compounds. Results from both docking and molecular dynamics simulations are consistent with the arylamides binding in the p53 peptide binding pocket. Simulations of arylamides in the p53 binding pocket of hDM2 are consistent with binding, exhibiting similar structural dynamics in the pocket as simulations of known hDM2 binders Nutlin-2 and a benzodiazepinedione compound. Arylamide conformations converge towards the same region of the binding pocket on the 20 ns time scale, and most, though not all dihedrals in the binding pocket are well sampled on this timescale. We show that there are two putative classes of binding modes for arylamide compounds supported equally by the modeling evidence. In the first, the arylamide compound lies parallel to the observed p53 helix. In the second class, not previously identified or proposed, the arylamide compound lies anti-parallel to the p53 helix.

  17. Reinventing suggestion systems for continuous improvement

    NARCIS (Netherlands)

    Schuring, R.W.; Luijten, Harald

    2001-01-01

    This article reports an experiment to increase the effectiveness of a suggestion system by deliberately applying principles of the kaizen and performance management. Design rules for suggestion systems are derived from these theories. The suggestion system that resulted differs from traditional

  18. The functional anatomy of suggested limb paralysis.

    Science.gov (United States)

    Deeley, Quinton; Oakley, David A; Toone, Brian; Bell, Vaughan; Walsh, Eamonn; Marquand, Andre F; Giampietro, Vincent; Brammer, Michael J; Williams, Steven C R; Mehta, Mitul A; Halligan, Peter W

    2013-02-01

    Suggestions of limb paralysis in highly hypnotically suggestible subjects have been employed to successfully model conversion disorders, revealing similar patterns of brain activation associated with attempted movement of the affected limb. However, previous studies differ with regard to the executive regions involved during involuntary inhibition of the affected limb. This difference may have arisen as previous studies did not control for differences in hypnosis depth between conditions and/or include subjective measures to explore the experience of suggested paralysis. In the current study we employed functional magnetic resonance imaging (fMRI) to examine the functional anatomy of left and right upper limb movements in eight healthy subjects selected for high hypnotic suggestibility during (i) hypnosis (NORMAL) and (ii) attempted movement following additional left upper limb paralysis suggestions (PARALYSIS). Contrast of left upper limb motor function during NORMAL relative to PARALYSIS conditions revealed greater activation of contralateral M1/S1 and ipsilateral cerebellum, consistent with the engagement of these regions in the completion of movements. By contrast, two significant observations were noted in PARALYSIS relative to NORMAL conditions. In conjunction with reports of attempts to move the paralysed limb, greater supplementary motor area (SMA) activation was observed, a finding consistent with the role of SMA in motor intention and planning. The anterior cingulate cortex (ACC, BA 24) was also significantly more active in PARALYSIS relative to NORMAL conditions - suggesting that ACC (BA 24) may be implicated in involuntary, as well as voluntary inhibition of prepotent motor responses. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Artificial pancreas: model predictive control design from clinical experience.

    Science.gov (United States)

    Toffanin, Chiara; Messori, Mirko; Di Palma, Federico; De Nicolao, Giuseppe; Cobelli, Claudio; Magni, Lalo

    2013-11-01

    The objective of this research is to develop a new artificial pancreas that takes into account the experience accumulated during more than 5000 h of closed-loop control in several clinical research centers. The main objective is to reduce the mean glucose value without exacerbating hypo phenomena. Controller design and in silico testing were performed on a new virtual population of the University of Virginia/Padova simulator. A new sensor model was developed based on the Comparison of Two Artificial Pancreas Systems for Closed-Loop Blood Glucose Control versus Open-Loop Control in Patients with Type 1 Diabetes trial AP@home data. The Kalman filter incorporated in the controller has been tuned using plasma and pump insulin as well as plasma and continuous glucose monitoring measures collected in clinical research centers. New constraints describing clinical knowledge not incorporated in the simulator but very critical in real patients (e.g., pump shutoff) have been introduced. The proposed model predictive control (MPC) is characterized by a low computational burden and memory requirements, and it is ready for an embedded implementation. The new MPC was tested with an intensive simulation study on the University of Virginia/Padova simulator equipped with a new virtual population. It was also used in some preliminary outpatient pilot trials. The obtained results are very promising in terms of mean glucose and number of patients in the critical zone of the control variability grid analysis. The proposed MPC improves on the performance of a previous controller already tested in several experiments in the AP@home and JDRF projects. This algorithm complemented with a safety supervision module is a significant step toward deploying artificial pancreases into outpatient environments for extended periods of time. © 2013 Diabetes Technology Society.

  20. Understanding H isotope adsorption and absorption of Al-alloys using modeling and experiments (LDRD: #165724)

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Donald K. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Zhou, Xiaowang [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Karnesky, Richard A. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Kolasinski, Robert [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Foster, Michael E. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Thurmer, Konrad [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Chao, Paul [Carnegie Mellon University, Pittsburgh, PA (United States); Epperly, Ethan Nicholas [Livermore Valley Charter Preparatory High School, Livermore, CA (United States); Zimmerman, Jonathan A. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Wong, Bryan M. [Univ. of California, Riverside, CA (United States); Sills, Ryan B. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States)

    2015-09-01

    Current austenitic stainless steel storage reservoirs for hydrogen isotopes (e.g. deuterium and tritium) have performance and operational life-limiting interactions (e.g. embrittlement) with H-isotopes. Aluminum alloys (e.g.AA2219), alternatively, have very low H-isotope solubilities, suggesting high resistance towards aging vulnerabilities. This report summarizes the work performed during the life of the Lab Directed Research and Development in the Nuclear Weapons investment area (165724), and provides invaluable modeling and experimental insights into the interactions of H isotopes with surfaces and bulk AlCu-alloys. The modeling work establishes and builds a multi-scale framework which includes: a density functional theory informed bond-order potential for classical molecular dynamics (MD), and subsequent use of MD simulations to inform defect level dislocation dynamics models. Furthermore, low energy ion scattering and thermal desorption spectroscopy experiments are performed to validate these models and add greater physical understanding to them.

  1. The use of regression for assessing a seasonal forecast model experiment

    Science.gov (United States)

    Benestad, Rasmus E.; Senan, Retish; Orsolini, Yvan

    2016-11-01

    We show how factorial regression can be used to analyse numerical model experiments, testing the effect of different model settings. We analysed results from a coupled atmosphere-ocean model to explore how the different choices in the experimental set-up influence the seasonal predictions. These choices included a representation of the sea ice and the height of top of the atmosphere, and the results suggested that the simulated monthly mean air temperatures poleward of the mid-latitudes were highly sensitivity to the specification of the top of the atmosphere, interpreted as the presence or absence of a stratosphere. The seasonal forecasts for the mid-latitudes to high latitudes were also sensitive to whether the model set-up included a dynamic or non-dynamic sea-ice representation, although this effect was somewhat less important than the role of the stratosphere. The air temperature in the tropics was insensitive to these choices.

  2. Where and what TMS activates: Experiments and modeling.

    Science.gov (United States)

    Laakso, Ilkka; Murakami, Takenobu; Hirata, Akimasa; Ugawa, Yoshikazu

    Despite recent developments in navigation and modeling techniques, the type and location of the structures that are activated by transcranial magnetic stimulation (TMS) remain unknown. We studied the relationships between electrophysiological measurements and electric fields induced in the brain to locate the TMS activation site. The active and resting motor thresholds of the first dorsal interosseous muscle were recorded in 19 subjects (7 female, 12 male, age 22 ± 4 years) using anteromedially oriented monophasic TMS at multiple locations over the left primary motor cortex (M1). Structural MR images were used to construct electric field models of each subject's head and brain. The cortical activation site was estimated by finding where the calculated electric fields best explained the coil-location dependency of the measured MTs. The experiments and modeling showed individual variations both in the measured motor thresholds (MTs) and in the computed electric fields. When the TMS coil was moved on the scalp, the calculated electric fields in the hand knob region were shown to vary consistently with the measured MTs. Group-level analysis indicated that the electric fields were significantly correlated with the measured MTs. The strongest correlations (R 2  = 0.69), which indicated the most likely activation site, were found in the ventral and lateral part of the hand knob. The site was independent of voluntary contractions of the target muscle. The study showed that TMS combined with personalized electric field modeling can be used for high-resolution mapping of the motor cortex. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Molecular modeling and simulation studies of recombinant laccase from Yersinia enterocolitica suggests significant role in the biotransformation of non-steroidal anti-inflammatory drugs

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Deepti; Rawat, Surender [Laboratory of Enzymology and Recombinant DNA Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak 124001, Haryana (India); Waseem, Mohd; Gupta, Sunita; Lynn, Andrew [School of Computational & Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); Nitin, Mukesh; Ramchiary, Nirala [School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); Sharma, Krishna Kant, E-mail: kekulsharma@gmail.com [Laboratory of Enzymology and Recombinant DNA Technology, Department of Microbiology, Maharshi Dayanand University, Rohtak 124001, Haryana (India)

    2016-01-08

    The YacK gene from Yersinia enterocolitica strain 7, cloned in pET28a vector and expressed in Escherichia coli BL21 (DE3), showed laccase activity when oxidized with 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and guaiacol. The recombinant laccase protein was purified and characterized biochemically with a molecular mass of ≈58 KDa on SDS-PAGE and showed positive zymogram with ABTS. The protein was highly robust with optimum pH 9.0 and stable at 70 °C upto 12 h with residual activity of 70%. Kinetic constants, K{sub m} values, for ABTS and guaiacol were 675 μM and 2070 μM, respectively, with corresponding Vmax values of 0.125 μmol/ml/min and 6500 μmol/ml/min. It also possess antioxidative property against BSA and Cu{sup 2+}/H{sub 2}O{sub 2} model system. Constant pH MD simulation studies at different protonation states of the system showed ABTS to be most stable at acidic pH, whereas, diclofenac at neutral pH. Interestingly, aspirin drifted out of the binding pocket at acidic and neutral pH, but showed stable binding at alkaline pH. The biotransformation of diclofenac and aspirin by laccase also corroborated the in silico results. This is the first report on biotransformation of non-steroidal anti-inflammatory drugs (NSAIDs) using recombinant laccase from gut bacteria, supported by in silico simulation studies. - Highlights: • Laccase from Yersinia enterocolitica strain 7 was expressed in Escherichia coli BL21 (DE3). • Recombinant laccase was found to be thermostable and alkali tolerant. • The in silico and experimental studied proves the biotransformation of NSAIDs. • Laccase binds to ligands differentially under different protonation state. • Laccase also possesses free radical scavenging property.

  4. Molecular modeling and simulation studies of recombinant laccase from Yersinia enterocolitica suggests significant role in the biotransformation of non-steroidal anti-inflammatory drugs

    International Nuclear Information System (INIS)

    Singh, Deepti; Rawat, Surender; Waseem, Mohd; Gupta, Sunita; Lynn, Andrew; Nitin, Mukesh; Ramchiary, Nirala; Sharma, Krishna Kant

    2016-01-01

    The YacK gene from Yersinia enterocolitica strain 7, cloned in pET28a vector and expressed in Escherichia coli BL21 (DE3), showed laccase activity when oxidized with 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and guaiacol. The recombinant laccase protein was purified and characterized biochemically with a molecular mass of ≈58 KDa on SDS-PAGE and showed positive zymogram with ABTS. The protein was highly robust with optimum pH 9.0 and stable at 70 °C upto 12 h with residual activity of 70%. Kinetic constants, K m values, for ABTS and guaiacol were 675 μM and 2070 μM, respectively, with corresponding Vmax values of 0.125 μmol/ml/min and 6500 μmol/ml/min. It also possess antioxidative property against BSA and Cu 2+ /H 2 O 2 model system. Constant pH MD simulation studies at different protonation states of the system showed ABTS to be most stable at acidic pH, whereas, diclofenac at neutral pH. Interestingly, aspirin drifted out of the binding pocket at acidic and neutral pH, but showed stable binding at alkaline pH. The biotransformation of diclofenac and aspirin by laccase also corroborated the in silico results. This is the first report on biotransformation of non-steroidal anti-inflammatory drugs (NSAIDs) using recombinant laccase from gut bacteria, supported by in silico simulation studies. - Highlights: • Laccase from Yersinia enterocolitica strain 7 was expressed in Escherichia coli BL21 (DE3). • Recombinant laccase was found to be thermostable and alkali tolerant. • The in silico and experimental studied proves the biotransformation of NSAIDs. • Laccase binds to ligands differentially under different protonation state. • Laccase also possesses free radical scavenging property.

  5. A model-based telecoupling analysis for the Patagonian shelf: a new suggested template on how to study global seabirds-fisheries interactions for sustainability

    Science.gov (United States)

    Huettmann, F.; Raya Rey, A.

    2016-12-01

    The Southwest Atlantic Ocean, and the extended Patagonian shelf in particular, presents us with a very complex ecosystem of global relevance for food security and global peace. It is a highly productive area and it maintains a great diversity and abundance of seabird species. Fisheries have been identified as a main stressor for the marine ecosystems and as one of the main causes of seabird population declines. Using the framework of telecoupling - a sophisticated description of natural and socioeconomic interactions over large distances - here we present a fresh holistic look at the dynamic fisheries and (endangered) seabird interactions for the Patagonian shelf. While data are sparse, we employ machine learning-based predictions for a more holistic overview. We found that these waters of the Patagonian Shelf are significantly affected by many nations and outside players. We found that the input, output and spill-over of the Patagonian shelf ecosystem are distributed virtually all over the globe. In addition, we also found `losers' (=nations and their citizens that are left out entirely from this global resource and its governance). Our findings are based on best-available public trade and fish harvest analysis for this region, linked with predictive modeling (machine learning and geographic information systems GIS) to generalize for nine seabird species. We conveniently extend this analysis with a perspective from the financial sector and policy that enables the Patagonian fisheries as international investment and development projects. As increasingly recognized elsewhere, we believe that telecoupling can serve as a new but rather sophisticated study template highlighting wider complexities, bottlenecks and sensitivities for a vastly improved conservation research on oceans and global sustainability questions.

  6. Transferring Approaches from Experience Oriented Disciplines to User Experience Design: The ExodUX Model

    OpenAIRE

    Kremer, Simon; Hoffmann, Andreas; Lindemann, Udo

    2015-01-01

    User Experience Design (UXD) addresses the increasing importance of emotional aspects in user product interaction and aims at creating holistic experiences. Within product development UXD is a rather young discipline. But other disciplines outside engineering design traditionally focus on creating experiences. We aim at transferring knowledge from those disciplines to support the design of fascinating User Experience (UX). We identified relevant experience disciplines and selected the three m...

  7. Recent Experiences in Aftershock Hazard Modelling in New Zealand

    Science.gov (United States)

    Gerstenberger, M.; Rhoades, D. A.; McVerry, G.; Christophersen, A.; Bannister, S. C.; Fry, B.; Potter, S.

    2014-12-01

    The occurrence of several sequences of earthquakes in New Zealand in the last few years has meant that GNS Science has gained significant recent experience in aftershock hazard and forecasting. First was the Canterbury sequence of events which began in 2010 and included the destructive Christchurch earthquake of February, 2011. This sequence is occurring in what was a moderate-to-low hazard region of the National Seismic Hazard Model (NSHM): the model on which the building design standards are based. With the expectation that the sequence would produce a 50-year hazard estimate in exceedance of the existing building standard, we developed a time-dependent model that combined short-term (STEP & ETAS) and longer-term (EEPAS) clustering with time-independent models. This forecast was combined with the NSHM to produce a forecast of the hazard for the next 50 years. This has been used to revise building design standards for the region and has contributed to planning of the rebuilding of Christchurch in multiple aspects. An important contribution to this model comes from the inclusion of EEPAS, which allows for clustering on the scale of decades. EEPAS is based on three empirical regressions that relate the magnitudes, times of occurrence, and locations of major earthquakes to regional precursory scale increases in the magnitude and rate of occurrence of minor earthquakes. A second important contribution comes from the long-term rate to which seismicity is expected to return in 50-years. With little seismicity in the region in historical times, a controlling factor in the rate is whether-or-not it is based on a declustered catalog. This epistemic uncertainty in the model was allowed for by using forecasts from both declustered and non-declustered catalogs. With two additional moderate sequences in the capital region of New Zealand in the last year, we have continued to refine our forecasting techniques, including the use of potential scenarios based on the aftershock

  8. Integrative modeling of eQTLs and cis-regulatory elements suggests mechanisms underlying cell type specificity of eQTLs.

    Directory of Open Access Journals (Sweden)

    Christopher D Brown

    Full Text Available Genetic variants in cis-regulatory elements or trans-acting regulators frequently influence the quantity and spatiotemporal distribution of gene transcription. Recent interest in expression quantitative trait locus (eQTL mapping has paralleled the adoption of genome-wide association studies (GWAS for the analysis of complex traits and disease in humans. Under the hypothesis that many GWAS associations tag non-coding SNPs with small effects, and that these SNPs exert phenotypic control by modifying gene expression, it has become common to interpret GWAS associations using eQTL data. To fully exploit the mechanistic interpretability of eQTL-GWAS comparisons, an improved understanding of the genetic architecture and causal mechanisms of cell type specificity of eQTLs is required. We address this need by performing an eQTL analysis in three parts: first we identified eQTLs from eleven studies on seven cell types; then we integrated eQTL data with cis-regulatory element (CRE data from the ENCODE project; finally we built a set of classifiers to predict the cell type specificity of eQTLs. The cell type specificity of eQTLs is associated with eQTL SNP overlap with hundreds of cell type specific CRE classes, including enhancer, promoter, and repressive chromatin marks, regions of open chromatin, and many classes of DNA binding proteins. These associations provide insight into the molecular mechanisms generating the cell type specificity of eQTLs and the mode of regulation of corresponding eQTLs. Using a random forest classifier with cell specific CRE-SNP overlap as features, we demonstrate the feasibility of predicting the cell type specificity of eQTLs. We then demonstrate that CREs from a trait-associated cell type can be used to annotate GWAS associations in the absence of eQTL data for that cell type. We anticipate that such integrative, predictive modeling of cell specificity will improve our ability to understand the mechanistic basis of human

  9. A Novel In Vitro CypD-Mediated p53 Aggregation Assay Suggests a Model for Mitochondrial Permeability Transition by Chaperone Systems.

    Science.gov (United States)

    Lebedev, Ivan; Nemajerova, Alice; Foda, Zachariah H; Kornaj, Maja; Tong, Michael; Moll, Ute M; Seeliger, Markus A

    2016-10-09

    Tissue necrosis as a consequence of ischemia-reperfusion injury and oxidative damage is a leading cause of permanent disability and death worldwide. The complete mechanism by which cells undergo necrosis upon oxidative stress is not understood. In response to an oxidative insult, wild-type p53 has been implicated as a central regulatory component of the mitochondrial permeability transition (mPT), triggering necrosis. This process is associated with cellular stabilization and translocation of p53 into the mitochondrial matrix. Here, we probe the mechanism by which p53 activates the key mPT regulator cyclophilin D (CypD). We explore the involvement of Trap1, an Hsp90-related mitochondrial matrix protein and a member of the mitochondrial unfolded protein response, and its ability to suppress mPT in a p53-dependent manner. Our study finds that catalytically active CypD causes strong aggregation of wild-type p53 protein (both full-length and isolated DNA-binding domain) into amyloid-type fibrils in vitro. The responsible CypD residues for this activity were mapped by NMR to the active site amino acids R55, F60, F113, and W121. The data also present a new proline isomerization assay for CypD by monitoring the aggregation of p53 as an indicator of CypD activity. Moreover, we find that the inhibition of Trap1 by the mitochondria-specific HSP90 ATPase antagonist Gamitrinib strongly sensitizes primary mouse embryonic fibroblasts to mPT and permeability transition pore opening in a p53- and CypD-dependent manner. We propose a mechanism by which the influx of unfolded p53 into the mitochondrial matrix in response to oxidative stress indirectly activates the normally inhibited CypD by displacing it from Trap1 complexes. This activates CypD's isomerase activity. Liberated CypD then isomerizes multiple proteins including p53 (causing p53 aggregation) and the structural components of the mPTP pore, inducing pore opening. This working model can now be tested in the future

  10. Solar model uncertainties, MSW analysis, and future solar neutrino experiments

    International Nuclear Information System (INIS)

    Hata, N.; Langacker, P.

    1994-01-01

    Various theoretical uncertainties in the standard solar model and in the Mikheyev-Smirnov-Wolfenstein (MSW) analysis are discussed. It is shown that two methods give consistent estimations of the solar neutrino flux uncertainties: (a) a simple parametrization of the uncertainties using the core temperature and the ncuelar production cross sections; (b) the Monte Carlo method of Bahcall and Ulrich. In the MSW analysis, we emphasize proper treatments of correlations of theoretical uncertainties between flux components and between different detectors, the Earth effect, and multiple solutions in a combined χ 2 procedure. In particular the large-angle solution of the combined observation is allowed at 95% C.L. only when the theoretical uncertainties are included. If their correlations were ignored, the region would be overestimated. The MSW solutions for various standard and nonstandard solar models are also shown. The MSW predictions of the global solutions for the future solar neutrino experiments are given, emphasizing the measurement of the energy spectrum and the day-night effect in Sudbury Neutrino Observatory and Super-Kamiokande to distinguish the two solutions

  11. Learning a generative probabilistic grammar of experience: a process-level model of language acquisition.

    Science.gov (United States)

    Kolodny, Oren; Lotem, Arnon; Edelman, Shimon

    2015-03-01

    We introduce a set of biologically and computationally motivated design choices for modeling the learning of language, or of other types of sequential, hierarchically structured experience and behavior, and describe an implemented system that conforms to these choices and is capable of unsupervised learning from raw natural-language corpora. Given a stream of linguistic input, our model incrementally learns a grammar that captures its statistical patterns, which can then be used to parse or generate new data. The grammar constructed in this manner takes the form of a directed weighted graph, whose nodes are recursively (hierarchically) defined patterns over the elements of the input stream. We evaluated the model in seventeen experiments, grouped into five studies, which examined, respectively, (a) the generative ability of grammar learned from a corpus of natural language, (b) the characteristics of the learned representation, (c) sequence segmentation and chunking, (d) artificial grammar learning, and (e) certain types of structure dependence. The model's performance largely vindicates our design choices, suggesting that progress in modeling language acquisition can be made on a broad front-ranging from issues of generativity to the replication of human experimental findings-by bringing biological and computational considerations, as well as lessons from prior efforts, to bear on the modeling approach. Copyright © 2014 Cognitive Science Society, Inc.

  12. Limits of quantitation — Yet another suggestion

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Jill; Wysoczanski, Artur; Voigtman, Edward, E-mail: voigtman@chem.umass.edu

    2014-06-01

    The work presented herein suggests that the limit of quantitation concept may be rendered substantially less ambiguous and ultimately more useful as a figure of merit by basing it upon the significant figure and relative measurement error ideas due to Coleman, Auses and Gram, coupled with the correct instantiation of Currie's detection limit methodology. Simple theoretical results are presented for a linear, univariate chemical measurement system with homoscedastic Gaussian noise, and these are tested against both Monte Carlo computer simulations and laser-excited molecular fluorescence experimental results. Good agreement among experiment, theory and simulation is obtained and an easy extension to linearly heteroscedastic Gaussian noise is also outlined. - Highlights: • True Currie detection limits are estimated. • Experimental results validate previous 2008 theory. • Linearly heteroscedastic system is correctly modeled.

  13. Optimum coagulant forecasting by modeling jar test experiments using ANNs

    Directory of Open Access Journals (Sweden)

    S. Haghiri

    2018-01-01

    Full Text Available Currently, the proper utilization of water treatment plants and optimizing their use is of particular importance. Coagulation and flocculation in water treatment are the common ways through which the use of coagulants leads to instability of particles and the formation of larger and heavier particles, resulting in improvement of sedimentation and filtration processes. Determination of the optimum dose of such a coagulant is of particular significance. A high dose, in addition to adding costs, can cause the sediment to remain in the filtrate, a dangerous condition according to the standards, while a sub-adequate dose of coagulants can result in the reducing the required quality and acceptable performance of the coagulation process. Although jar tests are used for testing coagulants, such experiments face many constraints with respect to evaluating the results produced by sudden changes in input water because of their significant costs, long time requirements, and complex relationships among the many factors (turbidity, temperature, pH, alkalinity, etc. that can influence the efficiency of coagulant and test results. Modeling can be used to overcome these limitations; in this research study, an artificial neural network (ANN multi-layer perceptron (MLP with one hidden layer has been used for modeling the jar test to determine the dosage level of used coagulant in water treatment processes. The data contained in this research have been obtained from the drinking water treatment plant located in Ardabil province in Iran. To evaluate the performance of the model, the mean squared error (MSE and correlation coefficient (R2 parameters have been used. The obtained values are within an acceptable range that demonstrates the high accuracy of the models with respect to the estimation of water-quality characteristics and the optimal dosages of coagulants; so using these models will allow operators to not only reduce costs and time taken to perform

  14. Historical and idealized climate model experiments: an intercomparison of Earth system models of intermediate complexity

    DEFF Research Database (Denmark)

    Eby, M.; Weaver, A. J.; Alexander, K.

    2013-01-01

    Both historical and idealized climate model experiments are performed with a variety of Earth system models of intermediate complexity (EMICs) as part of a community contribution to the Intergovernmental Panel on Climate Change Fifth Assessment Report. Historical simulations start at 850 CE...... and continue through to 2005. The standard simulations include changes in forcing from solar luminosity, Earth's orbital configuration, CO2, additional greenhouse gases, land use, and sulphate and volcanic aerosols. In spite of very different modelled pre-industrial global surface air temperatures, overall 20...

  15. The Hot Serial Cereal Experiment for modeling wheat response to temperature: field experiments and AgMIP-Wheat multi-model simulations

    NARCIS (Netherlands)

    Martre, P.; Kimball, B.A.; Ottman, M.J.; Wall, G.W.; White, J.; Asseng, S.; Ewert, F.; Cammarano, D.; Maiorano, Andrea; Supit, I.

    2017-01-01

    The data set reported here includes the part of a Hot Serial Cereal Experiment (HSC) experiment recently used in the AgMIP-Wheat project to analyze the uncertainty of 30 wheat models and quantify their response to temperature. The HSC experiment was conducted in an open-field in a semiarid

  16. Divertor plasma studies on DIII-D: Experiment and modeling

    International Nuclear Information System (INIS)

    West, W.P.; Brooks, N.H.; Allen, S.L.

    1996-09-01

    In a magnetically diverted tokamak, the scrape-off layer (SOL) and divertor plasma provides separation between the first wall and the core plasma, intercepting impurities generated at the wall before they reach the core plasma. The divertor plasma can also serve to spread the heat and particle flux over a large area of divertor structure wall using impurity radiation and neutral charge exchange, thus reducing peak heat and particle fluxes at the divertor strike plate. Such a reduction will be required in the next generation of tokamaks, for without it, the divertor engineering requirements are very demanding. To successfully demonstrate a radiative divertor, a highly radiative condition with significant volume recombination must be achieved in the divertor, while maintaining a low impurity content in the core plasma. Divertor plasma properties are determined by a complex interaction of classical parallel transport, anomalous perpendicular transport, impurity transport and radiation, and plasma wall interaction. In this paper the authors describe a set of experiments on DIII-D designed to provide detailed two dimensional documentation of the divertor and SOL plasma. Measurements have been made in operating modes where the plasma is attached to the divertor strike plate and in highly radiating cases where the plasma is detached from the divertor strike plate. They also discuss the results of experiments designed to influence the distribution of impurities in the plasma using enhanced SOL plasma flow. Extensive modeling efforts will be described which are successfully reproducing attached plasma conditions and are helping to elucidate the important plasma and atomic physics involved in the detachment process

  17. Post-mining water treatment. Nanofiltration of uranium-contaminated drainage. Experiments and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hoyer, Michael

    2017-07-01

    value of the relative permittivity differ by a factor of 2. This in turn has an influence on the membrane charge which is notably 60 times higher in order to compensate for the reduced contribution from the dielectric exclusion. These results suggest that the developed model is capable of describing nanofiltration of concentrated, complex, real water samples to a high degree of precision. The way is thus paved for modeling and experiment, e.g. for nanofiltration of other complex mine waters.

  18. A Model of Titan-like Chemistry to Connect Experiments and Cassini Observations

    Science.gov (United States)

    Raymond, Alexander W.; Sciamma-O’Brien, Ella; Salama, Farid; Mazur, Eric

    2018-02-01

    A numerical model is presented for interpreting the chemical pathways that lead to the experimental mass spectra acquired in the Titan Haze Simulation (THS) laboratory experiments and for comparing the electron density and temperature of the THS plasma to observations made at Titan by the Cassini spacecraft. The THS plasma is a pulsed glow-discharge experiment designed to simulate the reaction of N2/CH4-dominated gas in Titan's upper atmosphere. The transient, one-dimensional model of THS chemistry tracks the evolution of more than 120 species in the direction of the plasma flow. As the minor species C2H2 and C2H4 are added to the N2/CH4-based mixture, the model correctly predicts the emergence of reaction products with up to five carbon atoms in relative abundances that agree well with measured mass spectra. Chemical growth in Titan's upper atmosphere transpires through ion–neutral and neutral–neutral chemistry, and the main reactions involving a series of known atmospheric species are retrieved from the calculation. The model indicates that the electron density and chemistry are steady during more than 99% of the 300 μs long discharge pulse. The model also suggests that the THS ionization fraction and electron temperature are comparable to those measured in Titan's upper atmosphere. These findings reaffirm that the THS plasma is a controlled analog environment for studying the first and intermediate steps of chemistry in Titan's upper atmosphere.

  19. Partnerships for success: A collaborative support model to enhance the first year student experience

    Directory of Open Access Journals (Sweden)

    Johanna Einfalt

    2013-04-01

    Full Text Available Recent discourse about engaging first year students calls for more collaboration in terms of adopting a holistic approach to course delivery and support. This paper discusses a collaborative support model operating at a regional Australian university since 2008. In particular, it describes a collaborative support initiative emerging from this model that is based on providing an informal consultative space where students can drop-in and gain assessment support for research, writing and content. A focus group, online surveys and interviews with co-ordinators were conducted to evaluate the impact of this initiative. Findings suggest that this collaborative support model impacts on the first year student experience by: raising awareness about academic skills and the processes for researching and writing; promoting peer learning opportunities; building confidence and providing suitable support for a diverse range of students.

  20. Hydrogen transfer experiments and modelization in clay rocks for radioactive waste deep geological repository

    International Nuclear Information System (INIS)

    Boulin, P.

    2008-10-01

    Gases will be generated by corrosion of high radioactive waste containers in deep geological repositories. A gas phase will be generated. Gas pressure will build up and penetrated the geological formation. If gases do not penetrate the geological barrier efficiently, the pressure build up may create a risk of fracturing and of creation of preferential pathways for radionuclide migration. The present work focuses on Callovo-Oxfordian argillites characterisation. An experiment, designed to measure very low permeabilities, was used with hydrogen/helium and analysed using the Dusty Gas Model. Argillites close to saturation have an accessible porosity to gas transfer that is lower than 0,1% to 1% of the porosity. Analysis of the Knudsen effect suggests that this accessible network should be made of 50 nm to 200 nm diameter pores. The permeabilities values were integrated to an ANDRA operating model. The model showed that the maximum pressure expected near the repository would be 83 bar. (author)

  1. Initial Earthquake Centrifuge Model Experiments for the Study of Liquefaction

    National Research Council Canada - National Science Library

    Steedman, R

    1998-01-01

    .... A detailed experiment program has been developed for the first series of experiments studying the development of excess pore pressure in a level saturated sand bed under dynamic shaking at different effective overburden stresses. The initial experiments using the new large 'earthquake' shaker have been completed and data is presented and analysed.

  2. Experiences with a procedure for modeling product knowledge

    DEFF Research Database (Denmark)

    Hansen, Benjamin Loer; Hvam, Lars

    2002-01-01

    This paper presents experiences with a procedure for building configurators. The procedure has been used in an American company producing custom-made precision air conditioning equipment. The paper describes experiences with the use of the procedure and experiences with the project in general....

  3. Spent fuel dissolution rates: from experiments to models

    International Nuclear Information System (INIS)

    Gimenez, J.; Casa, I.; Clarens, F.; Rovira, M.; Pablo, J. de

    2003-01-01

    In this work we made a review on the different models and mechanisms that have been developed by different authors to explain the dissolution of spent nuclear fuel under oxic conditions. In most cases the oxidizing reagent used has been the molecular oxygen, but also some works with hydrogen peroxide or even with hypochloric acid can be found. Leaching experiments have been carried out with different types of spent nuclear fuel as well as with either chemical or natural analogues such as non irradiated uranium dioxide or natural uraninites, respectively. In oxygen and in the absence of bicarbonate ion, the data found in literature can be fitted considering the two-step oxidative dissolution mechanism developed by Torrero et al. (1998). This mechanism is able to explain the different reaction orders for pH oxygen concentration obtained depending on the experimental conditions. In the presence of bicarbonate, the data can be fitted considering the mechanism described de Pablo et al. (1999), which consists on two different steps: (1) oxidation of the surface of the solid and (2) surface co-ordination of the bicarbonate ion and dissolution of the complex formed. This model allows to explain different reaction orders for bicarbonate and oxygen concentration obtained by different authors. The development of a mechanism of UO 2 oxidation and dissolution in the presence of hydrogen peroxides is much more complied than in the case of oxygen because of the decomposition of the hydrogen peroxide, which is probably catalysed by the UO 2 (s). At present, more work is being directed to the elucidation of this mechanism, including the study of the influence of some radicals such as OH on the UO 2 dissolution. (Author)

  4. COUNTERCURRENT FLOW LIMITATION EXPERIMENTS AND MODELING FOR IMPROVED REACTOR SAFETY

    International Nuclear Information System (INIS)

    Vierow, Karen

    2008-01-01

    This project is investigating countercurrent flow and 'flooding' phenomena in light water reactor systems to improve reactor safety of current and future reactors. To better understand the occurrence of flooding in the surge line geometry of a PWR, two experimental programs were performed. In the first, a test facility with an acrylic test section provided visual data on flooding for air-water systems in large diameter tubes. This test section also allowed for development of techniques to form an annular liquid film along the inner surface of the 'surge line' and other techniques which would be difficult to verify in an opaque test section. Based on experiences in the air-water testing and the improved understanding of flooding phenomena, two series of tests were conducted in a large-diameter, stainless steel test section. Air-water test results and steam-water test results were directly compared to note the effect of condensation. Results indicate that, as for smaller diameter tubes, the flooding phenomena is predominantly driven by the hydrodynamics. Tests with the test sections inclined were attempted but the annular film was easily disrupted. A theoretical model for steam venting from inclined tubes is proposed herein and validated against air-water data. Empirical correlations were proposed for air-water and steam-water data. Methods for developing analytical models of the air-water and steam-water systems are discussed, as is the applicability of the current data to the surge line conditions. This report documents the project results from July 1, 2005 through June 30, 2008

  5. Semantic integration by pattern priming: experiment and cortical network model.

    Science.gov (United States)

    Lavigne, Frédéric; Longrée, Dominique; Mayaffre, Damon; Mellet, Sylvie

    2016-12-01

    Neural network models describe semantic priming effects by way of mechanisms of activation of neurons coding for words that rely strongly on synaptic efficacies between pairs of neurons. Biologically inspired Hebbian learning defines efficacy values as a function of the activity of pre- and post-synaptic neurons only. It generates only pair associations between words in the semantic network. However, the statistical analysis of large text databases points to the frequent occurrence not only of pairs of words (e.g., "the way") but also of patterns of more than two words (e.g., "by the way"). The learning of these frequent patterns of words is not reducible to associations between pairs of words but must take into account the higher level of coding of three-word patterns. The processing and learning of pattern of words challenges classical Hebbian learning algorithms used in biologically inspired models of priming. The aim of the present study was to test the effects of patterns on the semantic processing of words and to investigate how an inter-synaptic learning algorithm succeeds at reproducing the experimental data. The experiment manipulates the frequency of occurrence of patterns of three words in a multiple-paradigm protocol. Results show for the first time that target words benefit more priming when embedded in a pattern with the two primes than when only associated with each prime in pairs. A biologically inspired inter-synaptic learning algorithm is tested that potentiates synapses as a function of the activation of more than two pre- and post-synaptic neurons. Simulations show that the network can learn patterns of three words to reproduce the experimental results.

  6. COUNTERCURRENT FLOW LIMITATION EXPERIMENTS AND MODELING FOR IMPROVED REACTOR SAFETY

    Energy Technology Data Exchange (ETDEWEB)

    Vierow, Karen

    2008-09-26

    This project is investigating countercurrent flow and “flooding” phenomena in light water reactor systems to improve reactor safety of current and future reactors. To better understand the occurrence of flooding in the surge line geometry of a PWR, two experimental programs were performed. In the first, a test facility with an acrylic test section provided visual data on flooding for air-water systems in large diameter tubes. This test section also allowed for development of techniques to form an annular liquid film along the inner surface of the “surge line” and other techniques which would be difficult to verify in an opaque test section. Based on experiences in the air-water testing and the improved understanding of flooding phenomena, two series of tests were conducted in a large-diameter, stainless steel test section. Air-water test results and steam-water test results were directly compared to note the effect of condensation. Results indicate that, as for smaller diameter tubes, the flooding phenomena is predominantly driven by the hydrodynamics. Tests with the test sections inclined were attempted but the annular film was easily disrupted. A theoretical model for steam venting from inclined tubes is proposed herein and validated against air-water data. Empirical correlations were proposed for air-water and steam-water data. Methods for developing analytical models of the air-water and steam-water systems are discussed, as is the applicability of the current data to the surge line conditions. This report documents the project results from July 1, 2005 through June 30, 2008.

  7. Microfluidic model experiments on the injectability of monoclonal antibody solutions

    Science.gov (United States)

    Duchene, Charles; Filipe, Vasco; Nakach, Mostafa; Huille, Sylvain; Lindner, Anke

    2017-11-01

    Autoinjection devices that allow patients to self-administer medicine are becoming used more frequently; however, this advance comes with an increased need for precision in the injection process. The rare occurrence of protein aggregates in solutions of monoclonal antibodies constitutes a threat to the reliability of such devices. Here we study the flow of protein solutions containing aggregates in microfluidic model systems, mimicking injection devices, to gain fundamental understanding of the catastrophic clogging of constrictions of given size. We form aggregates by mechanically shaking or heating antibody solutions and then inject these solutions into microfluidic channels with varying types of constrictions. Geometrical clogging occurs when aggregates reach the size of the constriction and can in some cases be undone by increasing the applied pressure. We perform systematic experiments varying the relative aggregate size and the flow rate or applied pressure. The mechanical deformation of aggregates during their passage through constrictions is investigated to gain a better understanding of the clogging and unclogging mechanisms.

  8. Experiments and Modeling to Support Field Test Design

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Peter Jacob [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bourret, Suzanne Michelle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zyvoloski, George Anthony [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Boukhalfa, Hakim [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stauffer, Philip H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Weaver, Douglas James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-25

    Disposition of heat-generating nuclear waste (HGNW) remains a continuing technical and sociopolitical challenge. We define HGNW as the combination of both heat generating defense high level waste (DHLW) and civilian spent nuclear fuel (SNF). Numerous concepts for HGNW management have been proposed and examined internationally, including an extensive focus on geologic disposal (c.f. Brunnengräber et al., 2013). One type of proposed geologic material is salt, so chosen because of its viscoplastic deformation that causes self-repair of damage or deformation induced in the salt by waste emplacement activities (Hansen and Leigh, 2011). Salt as a repository material has been tested at several sites around the world, notably the Morsleben facility in Germany (c.f. Fahland and Heusermann, 2013; Wollrath et al., 2014; Fahland et al., 2015) and at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, NM. Evaluating the technical feasibility of a HGNW repository in salt is an ongoing process involving experiments and numerical modeling of many processes at many facilities.

  9. Symmetry breaking on density in escaping ants: experiment and alarm pheromone model.

    Directory of Open Access Journals (Sweden)

    Geng Li

    Full Text Available The symmetry breaking observed in nature is fascinating. This symmetry breaking is observed in both human crowds and ant colonies. In such cases, when escaping from a closed space with two symmetrically located exits, one exit is used more often than the other. Group size and density have been reported as having no significant impact on symmetry breaking, and the alignment rule has been used to model symmetry breaking. Density usually plays important roles in collective behavior. However, density is not well-studied in symmetry breaking, which forms the major basis of this paper. The experiment described in this paper on an ant colony displays an increase then decrease of symmetry breaking versus ant density. This result suggests that a Vicsek-like model with an alignment rule may not be the correct model for escaping ants. Based on biological facts that ants use pheromones to communicate, rather than seeing how other individuals move, we propose a simple yet effective alarm pheromone model. The model results agree well with the experimental outcomes. As a measure, this paper redefines symmetry breaking as the collective asymmetry by deducing the random fluctuations. This research indicates that ants deposit and respond to the alarm pheromone, and the accumulation of this biased information sharing leads to symmetry breaking, which suggests true fundamental rules of collective escape behavior in ants.

  10. Modelling and experiments on NTM stabilisation at ASDEX upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Urso, Laura

    2009-07-27

    In the next fusion device ITER the so-called neoclassical tearing modes (NTMs) are foreseen as being extremely detrimental to plasma confinement. This type of resistive instability is related to the presence in the plasma of magnetic islands. These are experimentally controlled with local electron cyclotron current drive (ECCD) and the island width decay during NTM stabilisation is modelled using the so-called Modified Rutherford equation. In this thesis, a modelling of the Modified Rutherford equation is carried out and simulations of the island width decay are compared with the experimentally observed ones in order to fit the two free machine-independent parameters present in the equation. A systematic study on a database of NTM stabilisation discharges from ASDEX Upgrade and JT-60U is done within the context of a multi-machine benchmark for extrapolating the ECCD power requirements for ITER. The experimental measurements in both devices are discussed by means of consistency checks and sensitivity analysis and used to evaluate the two fitting parameters present in the Modified Rutherford equation. The influence of the asymmetry of the magnetic island on stabilisation is for the first time included in the model and the effect of ECCD on the marginal island after which the mode naturally decays is quantified. The effect of radial misalignment and over-stabilisation during the experiment are found to be the key quantities affecting the NTM stabilisation. As a main result of this thesis, the extrapolation to ITER of the NTM stabilisation results from ASDEX Upgrade and JT-60U shows that 10MW of ECCD power are enough to stabilise large NTMs as long as the O-point of the island and the ECCD beam are perfectly aligned. In fact, the high ratio between the island size at saturation and the deposition width of the ECCD beam foreseen for ITER is found to imply a maximum allowable radial misalignment of 2-3 cm and little difference in terms of gained performance between

  11. Tracer simulation using a global general circulation model: Results from a midlatitude instantaneous source experiment

    International Nuclear Information System (INIS)

    Mahlman, J.D.; Moxim, W.J.

    1978-01-01

    An 11-level general circulation model with seasonal variation is used to perform an experiment on the dispersion of passive tracers. Specially constructed time-dependent winds from this model are used as input to a separate tracer model. The methodologies employed to construct the tracer model are described.The experiment presented is the evolution of a hypothetical instantaneous source of tracer on 1 Janaury with maximum initial concentration at 65 mb, 36 0 N, 180 0 E. The tracer is assumed to have no sources or sinks in the stratosphere, but is subject to removal processes in the lower troposphere.The experimental results reveal a number of similarities to observed tracer behavior, including the average poleward-downward slope of mixing ratio isopleths, strong tracer gradients across the tropopause, intrusion of tracer into the Southern Hemisphere lower stratosphere, and the long-term interhemispheric exchange rate. The model residence times show behavior intermediate to those exhibited for particulate radioactive debris and gaseous C 14 O 2 . This suggests that caution should be employed when either radioactive debris or C 14 O 2 data are used to develop empirical models for prediction of gaseous tracers which are efficiently removed in the troposphere.In this experiment, the tracer mixing ratio and potential vorticity evolve to very high correlations. Mechanisms for this correlation are discussed. The zonal mean tracer balances exhibit complex behavior among the various transport terms. At early stages, the tracer evolution is dominated by eddy effects. Later, a very large degree of self-cancellation between mean cell and eddy effects is observed. During seasonal transitions, however, this self-cancellation diminishes markedly, leading to significant changes in the zonal mean tracer distribution. A possible theoretical explanation is presented

  12. Efficient Optimization of Stimuli for Model-Based Design of Experiments to Resolve Dynamical Uncertainty

    Science.gov (United States)

    Mdluli, Thembi; Buzzard, Gregery T.; Rundell, Ann E.

    2015-01-01

    This model-based design of experiments (MBDOE) method determines the input magnitudes of an experimental stimuli to apply and the associated measurements that should be taken to optimally constrain the uncertain dynamics of a biological system under study. The ideal global solution for this experiment design problem is generally computationally intractable because of parametric uncertainties in the mathematical model of the biological system. Others have addressed this issue by limiting the solution to a local estimate of the model parameters. Here we present an approach that is independent of the local parameter constraint. This approach is made computationally efficient and tractable by the use of: (1) sparse grid interpolation that approximates the biological system dynamics, (2) representative parameters that uniformly represent the data-consistent dynamical space, and (3) probability weights of the represented experimentally distinguishable dynamics. Our approach identifies data-consistent representative parameters using sparse grid interpolants, constructs the optimal input sequence from a greedy search, and defines the associated optimal measurements using a scenario tree. We explore the optimality of this MBDOE algorithm using a 3-dimensional Hes1 model and a 19-dimensional T-cell receptor model. The 19-dimensional T-cell model also demonstrates the MBDOE algorithm’s scalability to higher dimensions. In both cases, the dynamical uncertainty region that bounds the trajectories of the target system states were reduced by as much as 86% and 99% respectively after completing the designed experiments in silico. Our results suggest that for resolving dynamical uncertainty, the ability to design an input sequence paired with its associated measurements is particularly important when limited by the number of measurements. PMID:26379275

  13. Adaptive stimulus optimization and model-based experiments for sensory systems neuroscience

    Directory of Open Access Journals (Sweden)

    Christopher eDiMattina

    2013-06-01

    Full Text Available In this paper we review several lines of recent work aimed at developing practical methods for adaptive on-line stimulus generation for sensory neurophysiology. We consider various experimental paradigms where on-line stimulus optimization is utilized, including the classical textit{optimal stimulus} paradigm where the goal of experiments is to identify a stimulus which maximizes neural responses, the textit{iso-response} paradigm which finds sets of stimuli giving rise to constant responses, and the textit{system identification} paradigm where the experimental goal is to estimate and possibly compare sensory processing models. We discuss various theoretical and practical aspects of adaptive firing rate optimization, including optimization with stimulus space constraints, firing rate adaptation, and possible network constraints on the optimal stimulus. We consider the problem of system identification, and show how accurate estimation of nonlinear models can be highly dependent on the stimulus set used to probe the network. We suggest that optimizing stimuli for accurate model estimation may make it possible to successfully identify nonlinear models which are otherwise intractable, and summarize several recent studies of this type. Finally, we present a two-stage stimulus design procedure which combines the dual goals of model estimation and model comparison and may be especially useful for system identification experiments where the appropriate model is unknown beforehand. We propose that fast, on-line stimulus optimization enabled by increasing computer power can make it practical to move sensory neuroscience away from a descriptive paradigm and towards a new paradigm of real-time model estimation and comparison.

  14. Controlled laboratory experiments and modeling of vegetative filter strips with shallow water tables

    Science.gov (United States)

    Fox, Garey A.; Muñoz-Carpena, Rafael; Purvis, Rebecca A.

    2018-01-01

    Natural or planted vegetation at the edge of fields or adjacent to streams, also known as vegetative filter strips (VFS), are commonly used as an environmental mitigation practice for runoff pollution and agrochemical spray drift. The VFS position in lowlands near water bodies often implies the presence of a seasonal shallow water table (WT). In spite of its potential importance, there is limited experimental work that systematically studies the effect of shallow WTs on VFS efficacy. Previous research recently coupled a new physically based algorithm describing infiltration into soils bounded by a water table into the VFS numerical overland flow and transport model, VFSMOD, to simulate VFS dynamics under shallow WT conditions. In this study, we tested the performance of the model against laboratory mesoscale data under controlled conditions. A laboratory soil box (1.0 m wide, 2.0 m long, and 0.7 m deep) was used to simulate a VFS and quantify the influence of shallow WTs on runoff. Experiments included planted Bermuda grass on repacked silt loam and sandy loam soils. A series of experiments were performed including a free drainage case (no WT) and a static shallow water table (0.3-0.4 m below ground surface). For each soil type, this research first calibrated VFSMOD to the observed outflow hydrograph for the free drainage experiments to parameterize the soil hydraulic and vegetation parameters, and then evaluated the model based on outflow hydrographs for the shallow WT experiments. This research used several statistical metrics and a new approach based on hypothesis testing of the Nash-Sutcliffe model efficiency coefficient (NSE) to evaluate model performance. The new VFSMOD routines successfully simulated the outflow hydrographs under both free drainage and shallow WT conditions. Statistical metrics considered the model performance valid with greater than 99.5% probability across all scenarios. This research also simulated the shallow water table experiments with

  15. Modeling, analysis and experiments for fusion nuclear technology: FNT progress report: Modeling and FINESSE

    International Nuclear Information System (INIS)

    Abdou, M.A.; Tillack, M.S.; Raffray, A.R.

    1987-01-01

    This document is a progress report on two technical studies carried out during 1986, both of which relate to the implementation phase of FNT. The first, which is a follow-up to FINESSE, focuses on specific key questions for: (1) very near-term (0 to 3 years) non-fusion experiments and facilities, and (2) FNT testing in a fusion facility. The second is the initial stage of a detailed effort to develop theory, models and computer codes for predicting the performance of nuclear components. Chapters are presented on (1) introduction and chapter summaries, (2) non-fusion experiments and facilities, (3) fusion testing issues, and (4) theory and modeling. Chapter 2 is an assessment of the relative advantages of many solid breeders, neutron multipliers and configurations. Various issues affecting design and cost of the blanket are examined in Chapter 3. Chapter 4 reports on the progress of the initial stage of an effort to develop theory and analytical and numerical models for nuclear components. A major part of the effort has focused on modeling of MHD effects for liquid metal blankets. Progress has also been made on modeling tritium transport and inventory in solid breeder blankets and the thermomechanical behavior of liquid-metal-cooled limiters

  16. Visual Prompts or Volunteer Models: An Experiment in Recycling

    Directory of Open Access Journals (Sweden)

    Zi Yin Lin

    2016-05-01

    Full Text Available Successful long-term programs for urban residential food waste sorting are very rare, despite the established urgent need for them in cities for waste reduction, pollution reduction and circular resource economy reasons. This study meets recent calls to bridge policy makers and academics, and calls for more thorough analysis of operational work in terms of behavioral determinants, to move the fields on. It takes a key operational element of a recently reported successful food waste sorting program—manning of the new bins by volunteers—and considers the behavioral determinants involved in order to design a more scalable and cheaper alternative—the use of brightly colored covers with flower designs on three sides of the bin. The two interventions were tested in a medium-scale, real-life experimental set-up that showed that they had statistically similar results: high effective capture rates of 32%–34%, with low contamination rates. The success, low cost and simple implementation of the latter suggests it should be considered for large-scale use. Candidate behavioral determinants are prompts, emotion and knowledge for the yellow bin intervention, and for the volunteer intervention they are additionally social influence, modeling, role clarification, and moderators of messenger type and interpersonal or tailored messaging.

  17. Model slope infiltration experiments for shallow landslides early warning

    Science.gov (United States)

    Damiano, E.; Greco, R.; Guida, A.; Olivares, L.; Picarelli, L.

    2009-04-01

    simple empirical models [Versace et al., 2003] based on correlation between some features of rainfall records (cumulated height, duration, season etc.) and the correspondent observed landslides. Laboratory experiments on instrumented small scale slope models represent an effective way to provide data sets [Eckersley, 1990; Wang and Sassa, 2001] useful for building up more complex models of landslide triggering prediction. At the Geotechnical Laboratory of C.I.R.I.AM. an instrumented flume to investigate on the mechanics of landslides in unsaturated deposits of granular soils is available [Olivares et al. 2003; Damiano, 2004; Olivares et al., 2007]. In the flume a model slope is reconstituted by a moist-tamping technique and subjected to an artificial uniform rainfall since failure happens. The state of stress and strain of the slope is monitored during the entire test starting from the infiltration process since the early post-failure stage: the monitoring system is constituted by several mini-tensiometers placed at different locations and depths, to measure suction, mini-transducers to measure positive pore pressures, laser sensors, to measure settlements of the ground surface, and high definition video-cameras to obtain, through a software (PIV) appositely dedicated, the overall horizontal displacement field. Besides, TDR sensors, used with an innovative technique [Greco, 2006], allow to reconstruct the water content profile of soil along the entire thickness of the investigated deposit and to monitor its continuous changes during infiltration. In this paper a series of laboratory tests carried out on model slopes in granular pyroclastic soils taken in the mountainous area north-eastern of Napoli, are presented. The experimental results demonstrate the completeness of information provided by the various sensors installed. In particular, very useful information is given by the coupled measurements of soil water content by TDR and suction by tensiometers. Knowledge of

  18. A robotics-based approach to modeling of choice reaching experiments on visual attention

    Directory of Open Access Journals (Sweden)

    Soeren eStrauss

    2012-04-01

    Full Text Available The paper presents a robotics-based model for choice reaching experiments on visual attention. In these experiments participants were asked to make rapid reach movements towards a target in an odd-colour search task, i.e. reaching for a green square among red squares and vice versa (e.g. Song & Nakayama, 2008. Interestingly these studies found that in a high number of trials movements were initially directed towards a distractor and only later were adjusted towards the target. These curved trajectories occurred particularly frequently when the target in the directly preceding trial had a different colour (priming effect. Our model is embedded in a closed-loop control of a LEGO robot arm aiming to mimic these reach movements. The model is based on our earlier work which suggests that target selection in visual search is implemented through parallel interactions between competitive and cooperative processes in the brain (Heinke & Backhaus, 2011; Heinke & Humphreys, 2003. To link this model with the control of the robot arm we implemented a topological representation of movement parameters following the dynamic field theory (Erlhagen & Schoener, 2002. The robot arm is able to mimic the results of the odd-colour search task including the priming effect and also generates human-like trajectories with a bell-shaped velocity profile. Theoretical implications and predictions are discussed in the paper.

  19. Vacuum System and Modeling for the Materials Plasma Exposure Experiment

    International Nuclear Information System (INIS)

    Lumsdaine, Arnold; Meitner, Steve; Graves, Van; Bradley, Craig; Stone, Chris

    2017-01-01

    Understanding the science of plasma-material interactions (PMI) is essential for the future development of fusion facilities. The design of divertors and first walls for the next generation of long-pulse fusion facilities, such as a Fusion Nuclear Science Facility (FNSF) or a DEMO, requires significant PMI research and development. In order to meet this need, a new linear plasma facility, the Materials Plasma Exposure Experiment (MPEX) is proposed, which will produce divertor relevant plasma conditions for these next generation facilities. The device will be capable of handling low activation irradiated samples and be able to remove and replace samples without breaking vacuum. A Target Exchange Chamber (TEC) which can be disconnected from the high field environment in order to perform in-situ diagnostics is planned for the facility as well. The vacuum system for MPEX must be carefully designed in order to meet the requirements of the different heating systems, and to provide conditions at the target similar to those expected in a divertor. An automated coupling-decoupling (“autocoupler”) system is designed to create a high vacuum seal, and will allow the TEC to be disconnected without breaking vacuum in either the TEC or the primary plasma materials interaction chamber. This autocoupler, which can be actuated remotely in the presence of the high magnetic fields, has been designed and prototyped, and shows robustness in a variety of conditions. The vacuum system has been modeled using a simplified finite element analysis, and indicates that the design goals for the pressures in key regions of the facility are achievable.

  20. Historical and idealized climate model experiments: an intercomparison of Earth system models of intermediate complexity

    Directory of Open Access Journals (Sweden)

    M. Eby

    2013-05-01

    Full Text Available Both historical and idealized climate model experiments are performed with a variety of Earth system models of intermediate complexity (EMICs as part of a community contribution to the Intergovernmental Panel on Climate Change Fifth Assessment Report. Historical simulations start at 850 CE and continue through to 2005. The standard simulations include changes in forcing from solar luminosity, Earth's orbital configuration, CO2, additional greenhouse gases, land use, and sulphate and volcanic aerosols. In spite of very different modelled pre-industrial global surface air temperatures, overall 20th century trends in surface air temperature and carbon uptake are reasonably well simulated when compared to observed trends. Land carbon fluxes show much more variation between models than ocean carbon fluxes, and recent land fluxes appear to be slightly underestimated. It is possible that recent modelled climate trends or climate–carbon feedbacks are overestimated resulting in too much land carbon loss or that carbon uptake due to CO2 and/or nitrogen fertilization is underestimated. Several one thousand year long, idealized, 2 × and 4 × CO2 experiments are used to quantify standard model characteristics, including transient and equilibrium climate sensitivities, and climate–carbon feedbacks. The values from EMICs generally fall within the range given by general circulation models. Seven additional historical simulations, each including a single specified forcing, are used to assess the contributions of different climate forcings to the overall climate and carbon cycle response. The response of surface air temperature is the linear sum of the individual forcings, while the carbon cycle response shows a non-linear interaction between land-use change and CO2 forcings for some models. Finally, the preindustrial portions of the last millennium simulations are used to assess historical model carbon-climate feedbacks. Given the specified forcing, there

  1. Response Surface Model Building Using Orthogonal Arrays for Computer Experiments

    Science.gov (United States)

    Unal, Resit; Braun, Robert D.; Moore, Arlene A.; Lepsch, Roger A.

    1997-01-01

    This study investigates response surface methods for computer experiments and discusses some of the approaches available. Orthogonal arrays constructed for computer experiments are studied and an example application to a technology selection and optimization study for a reusable launch vehicle is presented.

  2. Fund choice behavior and estimation of switching models: an experiment*

    NARCIS (Netherlands)

    Anufriev, M.; Bao, T.; Tuinstra, J.

    2013-01-01

    We run a laboratory experiment that contributes to the finance literature on "return chasing behavior" studying how investors switch between mutual funds driven by past performance of the funds. The subjects in this experiment make discrete choices between several (2, 3 or 4) experimental funds in

  3. Measurement and simulation of unmyelinated nerve electrostimulation: Lumbricus terrestris experiment and numerical model.

    Science.gov (United States)

    Šarolić, A; Živković, Z; Reilly, J P

    2016-06-21

    The electrostimulation excitation threshold of a nerve depends on temporal and frequency parameters of the stimulus. These dependences were investigated in terms of: (1) strength-duration (SD) curve for a single monophasic rectangular pulse, and (2) frequency dependence of the excitation threshold for a continuous sinusoidal current. Experiments were performed on the single-axon measurement setup based on Lumbricus terrestris having unmyelinated nerve fibers. The simulations were performed using the well-established SENN model for a myelinated nerve. Although the unmyelinated experimental model differs from the myelinated simulation model, both refer to a single axon. Thus we hypothesized that the dependence on temporal and frequency parameters should be very similar. The comparison was made possible by normalizing each set of results to the SD time constant and the rheobase current of each model, yielding the curves that show the temporal and frequency dependencies regardless of the model differences. The results reasonably agree, suggesting that this experimental setup and method of comparison with SENN model can be used for further studies of waveform effect on nerve excitability, including unmyelinated neurons.

  4. ForCent model development and testing using the Enriched Background Isotope Study experiment

    Energy Technology Data Exchange (ETDEWEB)

    Parton, W.J.; Hanson, P. J.; Swanston, C.; Torn, M.; Trumbore, S. E.; Riley, W.; Kelly, R.

    2010-10-01

    The ForCent forest ecosystem model was developed by making major revisions to the DayCent model including: (1) adding a humus organic pool, (2) incorporating a detailed root growth model, and (3) including plant phenological growth patterns. Observed plant production and soil respiration data from 1993 to 2000 were used to demonstrate that the ForCent model could accurately simulate ecosystem carbon dynamics for the Oak Ridge National Laboratory deciduous forest. A comparison of ForCent versus observed soil pool {sup 14}C signature ({Delta} {sup 14}C) data from the Enriched Background Isotope Study {sup 14}C experiment (1999-2006) shows that the model correctly simulates the temporal dynamics of the {sup 14}C label as it moved from the surface litter and roots into the mineral soil organic matter pools. ForCent model validation was performed by comparing the observed Enriched Background Isotope Study experimental data with simulated live and dead root biomass {Delta} {sup 14}C data, and with soil respiration {Delta} {sup 14}C (mineral soil, humus layer, leaf litter layer, and total soil respiration) data. Results show that the model correctly simulates the impact of the Enriched Background Isotope Study {sup 14}C experimental treatments on soil respiration {Delta} {sup 14}C values for the different soil organic matter pools. Model results suggest that a two-pool root growth model correctly represents root carbon dynamics and inputs to the soil. The model fitting process and sensitivity analysis exposed uncertainty in our estimates of the fraction of mineral soil in the slow and passive pools, dissolved organic carbon flux out of the litter layer into the mineral soil, and mixing of the humus layer into the mineral soil layer.

  5. On the Cutting Edge Professional Development Program - An effective model built from years of experience

    Science.gov (United States)

    Bruckner, M. Z.; Macdonald, H.; Beane, R. J.; Manduca, C. A.; Mcconnell, D. A.; Mogk, D. W.; Tewksbury, B. J.; Wiese, K.; Wysession, M. E.; Iverson, E. A. R.; Fox, S.

    2015-12-01

    The On the Cutting Edge (CE) program offers a successful model for designing and convening professional development events. Information about the model is now available on the CE website. The program model has evolved from more than 12 years of experience, building with input from strong leaders and participants. CE offers face-to-face, virtual, and hybrid events, and features a rich website that supports these professional development events as well as a growing community with a shared interest in effective geoscience teaching. Data from national surveys, participant feedback, and self-report data indicate the program's success in improving undergraduate geoscience education. Successes are also demonstrated in classroom observations using RTOP, indicating a significant difference in teaching style among participants and non-participants. A suite of web pages, with a planning timeline, provides guidance to those interested in designing and convening face-to-face or virtual events based on the CE model. The pages suggest ways to develop robust event goals and evaluation tools, how to choose strong leaders and recruit diverse participants, advice for designing effective event programs that utilize participant expertise, websites, and web tools, and suggestions for effectively disseminating event results and producing useful products. The CE model has been successfully transferred to projects that vary in scale and discipline. Best practices from the CE model include (1) thinking of the workshop as shared enterprise among conveners and participants; (2) incorporating conveners and participants who bring diverse viewpoints and approaches; (3) promoting structured discussions that utilize participants' expertise; (4) emphasizing practical strategies to effect change; and (5) using the website as a platform to prepare for the workshop, share ideas, and problem-solve challenges. Learn more about how to utilize this model for your project at:serc.carleton.edu/NAGTWorkshops/workshops/convene

  6. Architectural design of experience based factory model for software ...

    African Journals Online (AJOL)

    architectural design. Automation features are incorporated in the design in which workflow system and intelligent agents are integrated, and the facilitation of cloud environment is empowered to further support the automation. Keywords: architectural design; knowledge management; experience factory; workflow;

  7. Initial Earthquake Centrifuge Model Experiments for the Study of Liquefaction

    National Research Council Canada - National Science Library

    Steedman, R

    1998-01-01

    This project is a continuation of earlier research work by the Principal Investigator in support of the Earthquake Engineering Research Program, under the direction of the USAE Waterways Experiment...

  8. Modeling, experiments and optimization of an on-pipe thermoelectric generator

    International Nuclear Information System (INIS)

    Chen, Jie; Zuo, Lei; Wu, Yongjia; Klein, Jackson

    2016-01-01

    Highlights: • A novel design of on-pipe thermoelectric generator using heat pipe. • A heat pipe is used and increases power output by more than 6 times. • Detailed system level modeling on the heat transfer and energy conversion. • Lab-based experiments shows that system can harvest more than 2 W of energy. • An optimization towards the design indicates further improvement can be achieved. - Abstract: A thermoelectric energy harvester composed of two thermoelectric modules, a wicked copper-water heat pipe, and finned heat sinks has been designed, modeled, and tested. The harvester is proposed to power sensor nodes on heating/cooling, steam, or exhaust pipes like these in power stations, chemical plants and vehicle systems. A model to analyze the heat transfer and thermoelectric performance of the energy harvesting system has been developed and validated against experiments. The results show that the model predicts the system power output and temperature response with reasonable accuracy. The model developed in this paper can be adapted for use with general heat sink, heat pipe, and thermoelectric systems. The design, incorporating a heat pipe and two 1.1″ by 1.1″ Bi 2 Te 3 modules generates 2.25 W ± 0.13 W power output with a temperature difference of 128 °C ± 1.12 °C and source temperature of 246 °C ± 1.9 °C, which is more than enough to operate wireless sensors or some actuators. The use of a heat pipe in this design increased the power output by 6 times over conventional designs. Based on the model, further improvement of the power output and energy harvesting efficiency of the system has been suggested by optimizing the number of thermoelectric modules.

  9. Photo darkening in Rare earth doped silica: Model and Experiment

    DEFF Research Database (Denmark)

    Mattsson, Kent Erik

    2011-01-01

    A model for photo darkening based on chemical bond formation is presented. The formation process, color center spectral response and bleaching is discussed and model predictions is found to follow high power fiber laser operation...

  10. Hypnotic suggestion: opportunities for cognitive neuroscience.

    Science.gov (United States)

    Oakley, David A; Halligan, Peter W

    2013-08-01

    Hypnosis uses the powerful effects of attention and suggestion to produce, modify and enhance a broad range of subjectively compelling experiences and behaviours. For more than a century, hypnotic suggestion has been used successfully as an adjunctive procedure to treat a wide range of clinical conditions. More recently, hypnosis has attracted a growing interest from a cognitive neuroscience perspective. Recent studies using hypnotic suggestion show how manipulating subjective awareness in the laboratory can provide insights into brain mechanisms involved in attention, motor control, pain perception, beliefs and volition. Moreover, they indicate that hypnotic suggestion can create informative analogues of clinical conditions that may be useful for understanding these conditions and their treatments.

  11. Induced polarization of clay-sand mixtures: experiments and modeling

    International Nuclear Information System (INIS)

    Okay, G.; Leroy, P.; Tournassat, C.; Ghorbani, A.; Jougnot, D.; Cosenza, P.; Camerlynck, C.; Cabrera, J.; Florsch, N.; Revil, A.

    2012-01-01

    Document available in extended abstract form only. Frequency-domain induced polarization (IP) measurements consist of imposing an alternative sinusoidal electrical current (AC) at a given frequency and measuring the resulting electrical potential difference between two other non-polarizing electrodes. The magnitude of the conductivity and the phase lag between the current and the difference of potential can be expressed into a complex conductivity with the in-phase representing electro-migration and a quadrature conductivity representing the reversible storage of electrical charges (capacitive effect) of the porous material. Induced polarization has become an increasingly popular geophysical method for hydrogeological and environmental applications. These applications include for instance the characterization of clay materials used as permeability barriers in landfills or to contain various types of contaminants including radioactive wastes. The goal of our study is to get a better understanding of the influence of the clay content, clay mineralogy, and pore water salinity upon complex conductivity measurements of saturated clay-sand mixtures in the frequency range ∼1 mHz-12 kHz. The complex conductivity of saturated unconsolidated sand-clay mixtures was experimentally investigated using two types of clay minerals, kaolinite and smectite in the frequency range 1.4 mHz - 12 kHz. Four different types of samples were used, two containing mainly kaolinite (80% of the mass, the remaining containing 15% of smectite and 5% of illite/muscovite; 95% of kaolinite and 5% of illite/muscovite), and the two others containing mainly Na-smectite or Na-Ca-smectite (95% of the mass; bentonite). The experiments were performed with various clay contents (1, 5, 20, and 100% in volume of the sand-clay mixture) and salinities (distilled water, 0.1 g/L, 1 g/L, and 10 g/L NaCl solution). In total, 44 saturated clay or clay-sand mixtures were prepared. Induced polarization measurements

  12. Testing the HTA core model: experiences from two pilot projects

    DEFF Research Database (Denmark)

    Pasternack, Iris; Anttila, Heidi; Mäkelä, Marjukka

    2009-01-01

    OBJECTIVES: The aim of this study was to analyze and describe process and outcomes of two pilot assessments based on the HTA Core Model, discuss the applicability of the model, and explore areas of development. METHODS: Data were gathered from HTA Core Model and pilot Core HTA documents...

  13. Modelling and Experiments of a Standing Wave Piezomotor

    DEFF Research Database (Denmark)

    Andersen, B.; Helbo, Jan; Blanke, Mogens

    The paper presents a new contact model for standing wave piezomotors. The contact model is based on the Hertz theory for normal contact deformations and elastic contact theory for tangential loads. The contact theory is simplified into a model with discrete springs for normal and tangential loads...

  14. Towards a sufficiency-driven business model : Experiences and opportunities

    NARCIS (Netherlands)

    Bocken, N.M.P.; Short, SW

    2016-01-01

    Business model innovation is an important lever for change to tackle pressing sustainability issues. In this paper, ‘sufficiency’ is proposed as a driver of business model innovation for sustainability. Sufficiency-driven business models seek to moderate overall resource consumption by curbing

  15. Legal Education Reform: Modest Suggestions.

    Science.gov (United States)

    Watson, Alan

    2001-01-01

    Based on harsh criticism of legal education by students, offers suggestions for improvement that do not require additional time for law studies, will increase the exposure of students both to law as practice and to law as an intellectual discipline, and involve no greater burden on law schools. A main suggestion involves elimination of teaching…

  16. Aespoe Pillar Stability Experiment. Final coupled 3D thermo-mechanical modeling. Preliminary particle mechanical modeling

    International Nuclear Information System (INIS)

    Wanne, Toivo; Johansson, Erik; Potyondy, David

    2004-02-01

    SKB is planning to perform a large-scale pillar stability experiment called APSE (Aespoe Pillar Stability Experiment) at Aespoe HRL. The study is focused on understanding and control of progressive rock failure in hard crystalline rock and damage caused by high stresses. The elastic thermo-mechanical modeling was carried out in three dimensions because of the complex test geometry and in-situ stress tensor by using a finite-difference modeling software FLAC3D. Cracking and damage formation were modeled in the area of interest (pillar between two large scale holes) in two dimensions by using the Particle Flow Code (PFC), which is based on particle mechanics. FLAC and PFC were coupled to minimize the computer resources and the computing time. According to the modeling the initial temperature rises from 15 deg C to about 65 deg C in the pillar area during the heating period of 120 days. The rising temperature due to thermal expansion induces stresses in the pillar area and after 120 days heating the stresses have increased about 33% from the excavation induced maximum stress of 150 MPa to 200 MPa in the end of the heating period. The results from FLAC3D model showed that only regions where the crack initiation stress has exceeded were identified and they extended to about two meters down the hole wall. These could be considered the areas where damage may occur during the in-situ test. When the other hole is pressurized with a 0.8 MPa confining pressure it yields that 5 MPa more stress is needed to damage the rock than without confining pressure. This makes the damaged area in some degree smaller. High compressive stresses in addition to some tensile stresses might induce some AE (acoustic emission) activity in the upper part of the hole from the very beginning of the test and are thus potential areas where AE activities may be detected. Monitoring like acoustic emissions will be measured during the test execution. The 2D coupled PFC-FLAC modeling indicated that

  17. Aespoe Pillar Stability Experiment. Final coupled 3D thermo-mechanical modeling. Preliminary particle mechanical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Wanne, Toivo; Johansson, Erik; Potyondy, David [Saanio and Riekkola Oy, Helsinki (Finland)

    2004-02-01

    SKB is planning to perform a large-scale pillar stability experiment called APSE (Aespoe Pillar Stability Experiment) at Aespoe HRL. The study is focused on understanding and control of progressive rock failure in hard crystalline rock and damage caused by high stresses. The elastic thermo-mechanical modeling was carried out in three dimensions because of the complex test geometry and in-situ stress tensor by using a finite-difference modeling software FLAC3D. Cracking and damage formation were modeled in the area of interest (pillar between two large scale holes) in two dimensions by using the Particle Flow Code (PFC), which is based on particle mechanics. FLAC and PFC were coupled to minimize the computer resources and the computing time. According to the modeling the initial temperature rises from 15 deg C to about 65 deg C in the pillar area during the heating period of 120 days. The rising temperature due to thermal expansion induces stresses in the pillar area and after 120 days heating the stresses have increased about 33% from the excavation induced maximum stress of 150 MPa to 200 MPa in the end of the heating period. The results from FLAC3D model showed that only regions where the crack initiation stress has exceeded were identified and they extended to about two meters down the hole wall. These could be considered the areas where damage may occur during the in-situ test. When the other hole is pressurized with a 0.8 MPa confining pressure it yields that 5 MPa more stress is needed to damage the rock than without confining pressure. This makes the damaged area in some degree smaller. High compressive stresses in addition to some tensile stresses might induce some AE (acoustic emission) activity in the upper part of the hole from the very beginning of the test and are thus potential areas where AE activities may be detected. Monitoring like acoustic emissions will be measured during the test execution. The 2D coupled PFC-FLAC modeling indicated that

  18. The model of localized business community economic development under limited financial resources: computer model and experiment

    Directory of Open Access Journals (Sweden)

    Berg Dmitry

    2016-01-01

    Full Text Available Globalization processes now affect and are affected by most of organizations, different type resources, and the natural environment. One of the main restrictions initiated by these processes is the financial one: money turnover in global markets leads to its concentration in the certain financial centers, and local business communities suffer from the money lack. This work discusses the advantages of complementary currency introduction into a local economics. By the computer simulation with the engineered program model and the real economic experiment it was proved that the complementary currency does not compete with the traditional currency, furthermore, it acts in compliance with it, providing conditions for the sustainable business community development.

  19. Technological Learning in Energy Models: Experience and Scenario Analysis with MARKAL and the ERIS Model Prototype

    International Nuclear Information System (INIS)

    Barreto, L.; Kypreos, S.

    1999-09-01

    Understanding technology dynamics, a fundamental driving factor of the evolution of energy systems, is essential for sound policy formulation and decision making. Technological change is not an autonomous process, but evolves from a number of endogenous interactions within the social system. Technologies evolve and improve only if experience with them is possible. Efforts must be devoted to improve our analytical tools concerning the treatment given to the technological variable, recognising the cumulative and gradual nature of technological change and the important role played by learning processes. This report presents a collection of works developed by the authors concerning the endogenisation of technological change in energy optimisation models, as a contribution to the Energy Technology Dynamics and Advanced Energy System Modelling Project (TEEM), developed in the framework of the Non Nuclear Energy Programme JOULE III of the European Union (DGXII). Here, learning curves, an empirically observed manifestation of the cumulative technological learning processes, are endogenised in two energy optimisation models. MARKAL, a widely used bottom-up model developed by the ETSAP programme of the IEA and ERIS, a model prototype, developed within the TEEM project for assessing different concepts and approaches. The methodological approach is described and some results and insights derived from the model analyses are presented. The incorporation of learning curves results in significantly different model outcomes than those obtained with traditional approaches. New, innovative technologies, hardly considered by the standard models, are introduced to the solution when endogenous learning is present. Up-front investments in initially expensive, but promising, technologies allow the necessary accumulation of experience to render them cost-effective. When uncertainty in emission reduction commitments is considered, the results point also in the direction of undertaking early

  20. Technological Learning in Energy Models: Experience and Scenario Analysis with MARKAL and the ERIS Model Prototype

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, L.; Kypreos, S.

    1999-09-01

    Understanding technology dynamics, a fundamental driving factor of the evolution of energy systems, is essential for sound policy formulation and decision making. Technological change is not an autonomous process, but evolves from a number of endogenous interactions within the social system. Technologies evolve and improve only if experience with them is possible. Efforts must be devoted to improve our analytical tools concerning the treatment given to the technological variable, recognising the cumulative and gradual nature of technological change and the important role played by learning processes. This report presents a collection of works developed by the authors concerning the endogenisation of technological change in energy optimisation models, as a contribution to the Energy Technology Dynamics andAdvanced Energy System Modelling Project (TEEM), developed in the framework of the Non Nuclear Energy Programme JOULE III of the European Union (DGXII). Here, learning curves, an empirically observed manifestation of the cumulative technological learning processes, are endogenised in two energy optimisation models. MARKAL, a widely used bottom-up model developed by the ETSAP programme of the IEA and ERIS, a model prototype, developed within the TEEM project for assessing different concepts and approaches. The methodological approach is described and some results and insights derived from the model analyses are presented. The incorporation of learning curves results in significantly different model outcomes than those obtained with traditional approaches. New, innovative technologies, hardly considered by the standard models, are introduced to the solution when endogenous learning is present. Up-front investments in initially expensive, but promising, technologies allow the necessary accumulation of experience to render them cost-effective. When uncertainty in emission reduction commitments is considered, the results point also in the direction of undertaking early

  1. Cultivating Native American scientists: an application of an Indigenous model to an undergraduate research experience

    Science.gov (United States)

    McMahon, Tracey R.; Griese, Emily R.; Kenyon, DenYelle Baete

    2018-03-01

    With growing evidence demonstrating the impact of undergraduate research experiences on educational persistence, efforts are currently being made to expand these opportunities within universities and research institutions throughout the United States. Recruiting underrepresented students into these programs has become an increasingly popular method of promoting diversity in science. Given the low matriculation into postsecondary education and completion rates among Native Americans, there is a great need for Native American undergraduate research internships. Although research has shown that Western education models tend to be less effective with Native populations, the implementation of indigenous epistemologies and pedagogies within higher education, including research experiences, is rare. This study explores the applicability of a cognitive apprenticeship merged with an indigenous approach, the Circle of Courage, to build a scientific learning environment and enhance the academic and professional development of Native students engaged in an undergraduate research experience in the health sciences. Data were drawn from focus groups with 20 students who participated in this program in 2012-2014. Questions explored the extent to which relational bonds between students and mentors were cultivated as well as the impact of this experience on the development of research skills, intellectual growth, academic and professional self-determination, and the attachment of meaning to their research experiences. Data were analyzed via deductive content analysis, allowing for an assessment of how the theoretical constructs inherent to this model (belonging, mastery, independence, and generosity) impacted students. Findings suggest that engaging Native students in research experiences that prioritize the needs of belonging, mastery, independence, and generosity can be a successful means of fostering a positive learning environment, in which students felt like significant members

  2. Mental models and learning from experience in nuclear power plants

    International Nuclear Information System (INIS)

    Carroll, J.S.

    1992-01-01

    This paper proposes that the improvement of plant functioning and the enhancement of safe performance depend greatly on the ability to interpret experience from within and outside the plant: Plants are learning organizations. The management of risk thus involves learning to identify and reduce entry into precursor situations and to recover rapidly from deficiencies. Various learning mechanisms exist that analyze plant incidents and disseminate this information inside plants, across plants, and worldwide, including, for example, various Institute of Nuclear Power Operations and International Atomic Energy Agency programs. Underlying these learning processes are plant employees' own understanding and interpretation of operational experience

  3. Fission neutrons experiments, evaluation, modeling and open problems

    CERN Document Server

    Kornilov, Nikolay

    2014-01-01

    Although the fission of heavy nuclei was discovered over 75 years ago, many problems and questions still remain to be addressed and answered. The reader will be presented with an old, but persistent problem of this field: The contradiction between Prompt Fission Neutron (PFN) spectra measured with differential (microscopic) experiments and integral (macroscopic and benchmark) experiments (the Micro-Macro problem). The difference in average energy is rather small ~3% but it is stable and we cannot explain the difference due to experimental uncertainties. Can we measure the PFN spectrum with hig

  4. Calibration of a finite element composite delamination model by experiments

    DEFF Research Database (Denmark)

    Gaiotti, M.; Rizzo, C.M.; Branner, Kim

    2013-01-01

    by a previously established modeling strategy (Branner et al., 2011; Gaiotti & Rizzo, 2011), using a pure shell model where the delamination is accounted for by properly offsetting its surfaces and connecting them to the intact plate via rigid link constraining algorithms. The numerical model developed...... modes related to the production methods is presented in this paper. A microscopic analysis of the fracture surfaces was carried out in order to better understand the failure mechanisms. © 2013 Taylor & Francis Group....

  5. Infant Care Suggestions for Parents

    Science.gov (United States)

    ... bones, that are in various stages of healing. Handling Suggestions • All movements should be slow, methodical and ... holding, lifting, diapering, and general infant care. The return demonstration will ensure that the parents are comfortable ...

  6. Informing Soil Carbon Models with Data from Global Change Experiments: Challenges and Opportunities

    Science.gov (United States)

    Van Groenigen, K. J.

    2015-12-01

    The soil carbon (C) pool may play an important role in determining the rate of climate change, but its response to future atmospheric conditions is uncertain. Elevated atmospheric CO2 concentrations, warming and nitrogen enrichment are known to affect plant productivity and soil microbial communities, with possible consequences for the turnover rate of soil C pools. Can we improve predictions of soil C dynamics under global change scenarios by informing soil C models with data from manipulative experiments? In a previous analysis, we combined meta-analysis with data assimlation and showed how elevated CO2 increases decomposition rates in a one-pool soil C model. Two-pool models may better represent long-term soil C dynamics, but when we refit our data to a two-pool soil C model, we arrived at similar conclusions. In addition, elevated CO2 decreased the carbon use efficiency of soil microbes, thereby further reducing the potential for soil C storage. We also present preliminary results from a two-pool analysis on the effect of warming on soil C dynamics. We will discuss the so-called "false priming effect" (i.e., the idea that a step increase in soil C input increases the size of the labile soil C pool, giving the impression of an increase in overall decomposition rates), and possible approaches to correct for this effect. To rule out the possibility of artifacts associated with simplified model structures, we suggest that future data-assimilation efforts on soil C dynamics be done using multi-pool models. Models that explicitly represent microbial dynamics may yield important insights as well. However, as models become more complicated, they must also be more constrained by empirical data. We will outline a few approaches on how to do this.

  7. Towards a model of teaching practice experience informed by ...

    African Journals Online (AJOL)

    The study investigates the interrelationships between teaching practice experience and the training of traditional healers amongst the Batlokwa and Bakwena communities in Madikwe, the North West Province in South Africa. The article uses a participatory and case study approach to determine aspects of convergence and ...

  8. The Chinese Experience: From Yellow Peril to Model Minority

    Science.gov (United States)

    Wong, Legan

    1976-01-01

    Argues that for too long the experiences of the Chinese population in America have been either shrouded in misconception or totally ignored, and that this country must recognize and deal with the issues affecting this community. Learning about Chinese Americans will allow us to reexamine governmental policies towards racial and ethnic groups and…

  9. Modelling and Experiments of a Standing Wave Piezomotor

    DEFF Research Database (Denmark)

    Helbo, Jan; Andersen, Brian; Blanke, Mogens

    2002-01-01

    which allows the calculation of slip/stick transitions. Simulations show that tip trajectories in general cannot be prescribed. The paper presents the principle of a bending resonator. Experiments indicate that the bending vibrations are too small to generate rotor rotations. However, due to unintended...

  10. The Living Dead: Transformative Experiences in Modelling Natural Selection

    Science.gov (United States)

    Petersen, Morten Rask

    2017-01-01

    This study considers how students change their coherent conceptual understanding of natural selection through a hands-on simulation. The results show that most students change their understanding. In addition, some students also underwent a transformative experience and used their new knowledge in a leisure time activity. These transformative…

  11. Event-based Simulation Model for Quantum Optics Experiments

    NARCIS (Netherlands)

    De Raedt, H.; Michielsen, K.; Jaeger, G; Khrennikov, A; Schlosshauer, M; Weihs, G

    2011-01-01

    We present a corpuscular simulation model of optical phenomena that does not require the knowledge of the solution of a wave equation of the whole system and reproduces the results of Maxwell's theory by generating detection events one-by-one. The event-based corpuscular model gives a unified

  12. The JCSS probabilistic model code: Experience and recent developments

    NARCIS (Netherlands)

    Chryssanthopoulos, M.; Diamantidis, D.; Vrouwenvelder, A.C.W.M.

    2003-01-01

    The JCSS Probabilistic Model Code (JCSS-PMC) has been available for public use on the JCSS website (www.jcss.ethz.ch) for over two years. During this period, several examples have been worked out and new probabilistic models have been added. Since the engineering community has already been exposed

  13. Funding models in palliative care: Lessons from international experience

    NARCIS (Netherlands)

    Groeneveld, E.I.; Cassel, J.B.; Bausewein, C.; Csikos, A.; Krajnik, M.; Ryan, K.; Haugen, D.F.; Eychmueller, S.; Gudat Keller, H.; Allan, S.; Hasselaar, J.G.J.; García-Baquero Merino, T.; Swetenham, K.; Piper, K.; Furst, C.J.; Murtagh, F.E.

    2017-01-01

    BACKGROUND: Funding models influence provision and development of palliative care services. As palliative care integrates into mainstream health care provision, opportunities to develop funding mechanisms arise. However, little has been reported on what funding models exist or how we can learn from

  14. Spectral evaluation of Earth geopotential models and an experiment ...

    Indian Academy of Sciences (India)

    As the number of Earth geopotential models (EGM) grows with the increasing number of data collected by dedicated satellite gravity missions, CHAMP, GRACE and GOCE, measuring the differences among the models and monitoring the improvements in gravity field recovery are required. This study assesses the ...

  15. The fence experiment - a first evaluation of shelter models

    DEFF Research Database (Denmark)

    Peña, Alfredo; Bechmann, Andreas; Conti, Davide

    2016-01-01

    We present a preliminary evaluation of shelter models of different degrees of complexity using full-scale lidar measurements of the shelter on a vertical plane behind and orthogonal to a fence. Model results accounting for the distribution of the relative wind direction within the observed direct...

  16. Event-Based Corpuscular Model for Quantum Optics Experiments

    NARCIS (Netherlands)

    Michielsen, K.; Jin, F.; Raedt, H. De

    A corpuscular simulation model of optical phenomena that does not require the knowledge of the solution of a wave equation of the whole system and reproduces the results of Maxwell's theory by generating detection events one-by-one is presented. The event-based corpuscular model is shown to give a

  17. Computer experiments with a coarse-grid hydrodynamic climate model

    International Nuclear Information System (INIS)

    Stenchikov, G.L.

    1990-01-01

    A climate model is developed on the basis of the two-level Mintz-Arakawa general circulation model of the atmosphere and a bulk model of the upper layer of the ocean. A detailed model of the spectral transport of shortwave and longwave radiation is used to investigate the radiative effects of greenhouse gases. The radiative fluxes are calculated at the boundaries of five layers, each with a pressure thickness of about 200 mb. The results of the climate sensitivity calculations for mean-annual and perpetual seasonal regimes are discussed. The CCAS (Computer Center of the Academy of Sciences) climate model is used to investigate the climatic effects of anthropogenic changes of the optical properties of the atmosphere due to increasing CO 2 content and aerosol pollution, and to calculate the sensitivity to changes of land surface albedo and humidity

  18. A controlled experiment in ground water flow model calibration

    Science.gov (United States)

    Hill, M.C.; Cooley, R.L.; Pollock, D.W.

    1998-01-01

    Nonlinear regression was introduced to ground water modeling in the 1970s, but has been used very little to calibrate numerical models of complicated ground water systems. Apparently, nonlinear regression is thought by many to be incapable of addressing such complex problems. With what we believe to be the most complicated synthetic test case used for such a study, this work investigates using nonlinear regression in ground water model calibration. Results of the study fall into two categories. First, the study demonstrates how systematic use of a well designed nonlinear regression method can indicate the importance of different types of data and can lead to successive improvement of models and their parameterizations. Our method differs from previous methods presented in the ground water literature in that (1) weighting is more closely related to expected data errors than is usually the case; (2) defined diagnostic statistics allow for more effective evaluation of the available data, the model, and their interaction; and (3) prior information is used more cautiously. Second, our results challenge some commonly held beliefs about model calibration. For the test case considered, we show that (1) field measured values of hydraulic conductivity are not as directly applicable to models as their use in some geostatistical methods imply; (2) a unique model does not necessarily need to be identified to obtain accurate predictions; and (3) in the absence of obvious model bias, model error was normally distributed. The complexity of the test case involved implies that the methods used and conclusions drawn are likely to be powerful in practice.Nonlinear regression was introduced to ground water modeling in the 1970s, but has been used very little to calibrate numerical models of complicated ground water systems. Apparently, nonlinear regression is thought by many to be incapable of addressing such complex problems. With what we believe to be the most complicated synthetic

  19. Pliocene Model Intercomparison Project (PlioMIP): Experimental Design and Boundary Conditions (Experiment 2)

    Science.gov (United States)

    Haywood, A. M.; Dowsett, H. J.; Robinson, M. M.; Stoll, D. K.; Dolan, A. M.; Lunt, D. J.; Otto-Bliesner, B.; Chandler, M. A.

    2011-01-01

    The Palaeoclimate Modelling Intercomparison Project has expanded to include a model intercomparison for the mid-Pliocene warm period (3.29 to 2.97 million yr ago). This project is referred to as PlioMIP (the Pliocene Model Intercomparison Project). Two experiments have been agreed upon and together compose the initial phase of PlioMIP. The first (Experiment 1) is being performed with atmosphere only climate models. The second (Experiment 2) utilizes fully coupled ocean-atmosphere climate models. Following on from the publication of the experimental design and boundary conditions for Experiment 1 in Geoscientific Model Development, this paper provides the necessary description of differences and/or additions to the experimental design for Experiment 2.

  20. Mechanical regulation of bone regeneration: theories, models, and experiments.

    Science.gov (United States)

    Betts, Duncan Colin; Müller, Ralph

    2014-01-01

    How mechanical forces influence the regeneration of bone remains an open question. Their effect has been demonstrated experimentally, which has allowed mathematical theories of mechanically driven tissue differentiation to be developed. Many simulations driven by these theories have been presented, however, validation of these models has remained difficult due to the number of independent parameters considered. An overview of these theories and models is presented along with a review of experimental studies and the factors they consider. Finally limitations of current experimental data and how this influences modeling are discussed and potential solutions are proposed.

  1. CELSS experiment model and design concept of gas recycle system

    Science.gov (United States)

    Nitta, K.; Oguchi, M.; Kanda, S.

    1986-01-01

    In order to prolong the duration of manned missions around the Earth and to expand the human existing region from the Earth to other planets such as a Lunar Base or a manned Mars flight mission, the controlled ecological life support system (CELSS) becomes an essential factor of the future technology to be developed through utilization of space station. The preliminary system engineering and integration efforts regarding CELSS have been carried out by the Japanese CELSS concept study group for clarifying the feasibility of hardware development for Space station experiments and for getting the time phased mission sets after FY 1992. The results of these studies are briefly summarized and the design and utilization methods of a Gas Recycle System for CELSS experiments are discussed.

  2. Experiments in Error Propagation within Hierarchal Combat Models

    Science.gov (United States)

    2015-09-01

    analysis confirms that there is a weak statistical difference between the R5FF and NOLH data sets. Figure 13. Statistical comparison of average Blue...addition, some may claim that the use of 10 sample indices is too weak statistically, so an additional experiment is conducted using 50 column...Uniform Automata Vector) Supplementary Manual. Auckland , N.Z.: Defense Technology Agency. Osborn, Kris. 2014. Navy Considers Future After Virginia

  3. Negative childhood experiences and adult love relationships: the role of internal working models of attachment.

    Science.gov (United States)

    McCarthy, Gerard; Maughan, Barbara

    2010-09-01

    This study investigated links between internal working models of attachment and the quality of adult love relationships in a high risk sample of women (n = 34), all of whom reported negative parenting in childhood. Half of the sample was identified as having a history of satisfying adult love relationships, while the remainder had experienced ongoing adult relationship problems. Measures of internal working models of attachment were made using the Adult Attachment Interview (AAI). A strong association was found between attachment classifications and the quality of adult love relationships. In addition, women with satisfying love relationships demonstrated significantly higher coherence of mind ratings than those with poor relationship histories. Insecure working models of attachment were associated with problems in adult love relationships. Although secure/autonomous attachment status was linked to optimal adult relationship outcomes, some women with a history of satisfying love relationships had insecure working models of attachment. These results suggest that the ways that adults process early experiences may influence later psychosocial functioning.

  4. Studies and Suggestions on Prewriting Activities

    Science.gov (United States)

    Zheng, Shigao; Dai, Weiping

    2012-01-01

    This paper studies and suggests the need for writing instruction by which students can experience writing as a creative process in exploring and communicating meaning. The prewriting activities generate ideas which can encourage a free flow of thoughts and help students discover both what they want to say and how to say it on paper. Through the…

  5. Suggestions for Structuring a Research Article

    Science.gov (United States)

    Klein, James D.; Reiser, Robert A.

    2014-01-01

    Researchers often experience difficulty as they attempt to prepare journal articles that describe their work. The purpose of this article is to provide researchers in the field of education with a series of suggestions as to how to clearly structure each section of a research manuscript that they intend to submit for publication in a scholarly…

  6. Separable finite viscoelasticity: integral-based models vs. experiments

    Science.gov (United States)

    Jridi, Nidhal; Arfaoui, Makrem; Hamdi, Adel; Salvia, Michelle; Bareille, Olivier; Ichchou, Mohamed; Ben Abdallah, Jalel

    2018-03-01

    In the present paper, the predictive capabilities of some integral-based finite strain viscoelastic models under the time-strain separability assumption have been investigated through experimental data for monotonic, relaxation and dynamic shear loads, in time and frequency domains. This analysis is instigated by experimental investigation results on two vulcanized carbon black filled rubbers. A unified identification procedure has been deployed to all models to determine the constitutive parameters. The monotonic tests were performed to capture the rate dependent and the long-term response of the materials. For the purely hyperelastic response, we considered the proposed hyperelastic potential proposed in Abaqus for incompressible materials. Relaxation tests were intended to identify the time-dependent material properties, and completed with a dynamic mechanical analysis. Models under consideration are Christensen, Fosdick & Yu, a variant of BKZ model, and the Simo model implemented in Abaqus. In the time domain, for each test case and for each model, the nominal stress is hence compared to experimental data, and the predictive capabilities are then examined with respect to three polynomial hyperelastic potentials forms. The dynamic properties had been investigated in the frequency domain with respect to the frequency and predeformation dependencies, and then comparison conclusions have been drawn.

  7. The Design of a Fire Source in Scale-Model Experiments with Smoke Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm; Brohus, Henrik; la Cour-Harbo, H.

    2004-01-01

    The paper describes the design of a fire and a smoke source for scale-model experiments with smoke ventilation. It is only possible to work with scale-model experiments where the Reynolds number is reduced compared to full scale, and it is demonstrated that special attention to the fire source...... (heat and smoke source) may improve the possibility of obtaining Reynolds number independent solutions with a fully developed flow. The paper shows scale-model experiments for the Ofenegg tunnel case. Design of a fire source for experiments with smoke ventilation in a large room and smoke movement...

  8. The Lived Experience of Counselor Education Doctoral Students in the Cohort Model at Duquesne University

    Science.gov (United States)

    Devine, Shirley

    2012-01-01

    This was a phenomenologically-oriented inquiry of the lived experiences of counselor education doctoral students in a cohort model. This inquiry sought to explore, describe, and understand students' "everyday" lived experiences in a cohort model in the Executive Doctoral Program in Counselor Education and Supervision (ExCES) at Duquesne…

  9. Why a noninteracting model works for shot noise in fractional charge experiments

    Science.gov (United States)

    Feldman, D. E.; Heiblum, Moty

    2017-03-01

    A fractional quasiparticle charge is a manifestation of strong interactions in the fractional quantum Hall effect. Nevertheless, shot noise of quasiparticles is well described by a formula, derived for noninteracting charges. We explain the success of that formula by proving that in the limits of strong and weak backscattering it holds irrespectively of microscopic details in weakly and strongly interacting systems alike. The derivation relies only on principles of statistical mechanics. We also derive an approximate model-independent formula for shot noise in the regime of intermediate backscattering. The equation is numerically close to the standard "noninteracting" fitting formula but suggests a different physical interpretation of the experimental results. We verify our theoretical predictions with a shot-noise experiment at the filling factor 3 /5 .

  10. Microstructure representations for sound absorbing fibrous media: 3D and 2D multiscale modelling and experiments

    Science.gov (United States)

    Zieliński, Tomasz G.

    2017-11-01

    The paper proposes and investigates computationally-efficient microstructure representations for sound absorbing fibrous media. Three-dimensional volume elements involving non-trivial periodic arrangements of straight fibres are examined as well as simple two-dimensional cells. It has been found that a simple 2D quasi-representative cell can provide similar predictions as a volume element which is in general much more geometrically accurate for typical fibrous materials. The multiscale modelling allowed to determine the effective speeds and damping of acoustic waves propagating in such media, which brings up a discussion on the correlation between the speed, penetration range and attenuation of sound waves. Original experiments on manufactured copper-wire samples are presented and the microstructure-based calculations of acoustic absorption are compared with the corresponding experimental results. In fact, the comparison suggested the microstructure modifications leading to representations with non-uniformly distributed fibres.

  11. Physical modeling of the boiling crisis: theory and experiment

    International Nuclear Information System (INIS)

    Nikolayev, Vadim; Beysens, Daniel; Chatain, Denis

    2008-01-01

    Full text of publication follows: In this presentation we describe a physical approach to the boiling crisis called also the critical heat flux (CHF) phenomenon. This approach is based on the hypothesis that the boiling crisis is triggered by spreading of individual vapor bubbles over the heater or equivalently by the growth of individual dry spots under the bubbles. The role of bubble coalescence is assumed to be secondary. The spreading is due to forces acting at the microscopic scale, in the neighborhood of the line of triple contact of liquid, vapor and heater where the local heat fluxes are the strongest. This picture is supposed to be independent on boiling conditions. It is confirmed by the pool boiling experiments carried out at extremely high pressures close to the gas-liquid critical point. Such unusual conditions are chosen to slow down the bubble growth sufficiently to be able to observe the dryout dynamics. In the above experiments it lasted during about a minute. To keep the usual bubble geometry, it is necessary to perform such experiments under reduced gravity. The numerical simulations are carried out for high pressures. They show two regimes of bubble growth. When the heat flux is smaller than a threshold value associated with the CHF, a vapor bubble grows and then leaves the heater by buoyancy. When the heat flux is larger than the CHF, the bubble spreads over the heater without leaving it in agreement with the experimental data. This occurs because the vapor recoil force causes both bubble spreading and strong adhesion to the heater. The CHF variation with system parameters predicted by simulations is briefly discussed. (authors) [fr

  12. Drilling in tempered glass – modelling and experiments

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik

    The present paper reports experimentally and numerically obtained results for the process of drilling in tempered glass. The experimental results are drilling depths on the edge in 19mm tempered glass with a known residual stress state measured by a scattered light polariscope. The experiments have...... of applying forces in such holes and thereby being able to mechanically assemble tempered glass without the need of drilling holes before the tempering process. The paper is the result of currently ongoing research and the results should be treated as so....

  13. Scaling - from experiments and modeling to the plant prototype

    International Nuclear Information System (INIS)

    Riznic, J.

    1992-01-01

    The need for changes in the size or scale of things given has rise to an entire branch of engineering known as scaling. We may use the definition that scaling deals with the structural and functional consequences of changes in size or scale among otherwise similar objects/engineering systems. Importance of application of scaling techniques in nuclear safety research is discussed in this paper. The applicability of results of safety phenomena related experiments to a full size nuclear power plant depends upon the scaling criteria to which the test facility was designed. (author)

  14. A model ecosystem experiment and its computational simulation studies

    International Nuclear Information System (INIS)

    Doi, M.

    2002-01-01

    Simplified microbial model ecosystem and its computer simulation model are introduced as eco-toxicity test for the assessment of environmental responses from the effects of environmental impacts. To take the effects on the interactions between species and environment into account, one option is to select the keystone species on the basis of ecological knowledge, and to put it in the single-species toxicity test. Another option proposed is to put the eco-toxicity tests as experimental micro ecosystem study and a theoretical model ecosystem analysis. With these tests, the stressors which are more harmful to the ecosystems should be replace with less harmful ones on the basis of unified measures. Management of radioactive materials, chemicals, hyper-eutrophic, and other artificial disturbances of ecosystem should be discussed consistently from the unified view point of environmental protection. (N.C.)

  15. Permeability model of sintered porous media: analysis and experiments

    Science.gov (United States)

    Flórez Mera, Juan Pablo; Chiamulera, Maria E.; Mantelli, Marcia B. H.

    2017-11-01

    In this paper, the permeability of porous media fabricated from copper powder sintering process was modeled and measured, aiming the use of the porosity as input parameter for the prediction of the permeability of sintering porous media. An expression relating the powder particle mean diameter with the permeability was obtained, based on an elementary porous media cell, which is physically represented by a duct formed by the arrangement of spherical particles forming a simple or orthorhombic packing. A circular duct with variable section was used to model the fluid flow within the porous media, where the concept of the hydraulic diameter was applied. Thus, the porous is modeled as a converging-diverging duct. The electrical circuit analogy was employed to determine two hydraulic resistances of the cell: based on the Navier-Stokes equation and on the Darcýs law. The hydraulic resistances are compared between themselves and an expression to determine the permeability as function of average particle diameter is obtained. The atomized copper powder was sifted to reduce the size dispersion of the particles. The porosities and permeabilities of sintered media fabricated from powders with particle mean diameters ranging from 20 to 200 microns were measured, by means of the image analysis method and using an experimental apparatus. The permeability data of a porous media, made of copper powder and saturated with distilled water, was used to compare with the permeability model. Permeability literature models, which considers that powder particles have the same diameter and include porosity data as input parameter, were compared with the present model and experimental data. This comparison showed to be quite good.

  16. Forced thermal cycling of catalytic reactions: experiments and modelling

    DEFF Research Database (Denmark)

    Jensen, Søren; Olsen, Jakob Lind; Thorsteinsson, Sune

    2007-01-01

    Recent studies of catalytic reactions subjected to fast forced temperature oscillations have revealed a rate enhancement increasing with temperature oscillation frequency. We present detailed studies of the rate enhancement up to frequencies of 2.5 Hz. A maximum in the rate enhancement is observed...... at about 1 Hz. A model for the rate enhancement that includes the surface kinetics and the dynamic partial pressure variations in the reactor is introduced. The model predicts a levelling off of the rate enhancement with frequency at about 1 Hz. The experimentally observed decrease above 1 Hz is explained...

  17. Designing experiments and analyzing data a model comparison perspective

    CERN Document Server

    Maxwell, Scott E

    2013-01-01

    Through this book's unique model comparison approach, students and researchers are introduced to a set of fundamental principles for analyzing data. After seeing how these principles can be applied in simple designs, students are shown how these same principles also apply in more complicated designs. Drs. Maxwell and Delaney believe that the model comparison approach better prepares students to understand the logic behind a general strategy of data analysis appropriate for various designs; and builds a stronger foundation, which allows for the introduction of more complex topics omitt

  18. A review of experiments testing the shoving model

    DEFF Research Database (Denmark)

    Hecksher, Tina; Dyre, J. C.

    2015-01-01

    interval over which the relaxation time increases by ten to fifteen decades. In this paper we have compiled all tests of the shoving model known to us. These involve rheological data obtained by different techniques, high-frequency sound-wave data, neutron scattering data for the vibrational mean......According to the shoving model the non-Arrhenius temperature dependence of supercooled liquids' relaxation time (or viscosity) derives from the fact that the high-frequency shear modulus is temperature dependent in the supercooled phase, often increasing a factor of three or four in the temperature...

  19. Hands-on experience with active appearance models

    DEFF Research Database (Denmark)

    Thodberg, Hans Henrik

    2002-01-01

    The aim of this work is to explore the performance of Active Appearance Models (AAMs) in reconstruction and interpretation of bones in hand radiographs. AAM is a generative approach that unifies image segmentation and image understanding. Initial locations for the AAM search are generated...... is used (1) to define a measure of fit that allows the models to self-evaluate and chose between the multiple found solutions, (2) to overcome obstacles in the image in the form of rings by predicting the missing part, and (3) to detect anomalies, e.g. rheumatoid arthritis. The shape scores are used...

  20. Means-End based Functional Modeling for Intelligent Control: Modeling and Experiments with an Industrial Heat Pump System

    DEFF Research Database (Denmark)

    Saleem, Arshad

    2007-01-01

    The purpose of this paper is to present a Multilevel Flow Model (MFM) of an industrial heat pump system and its use for diagnostic reasoning. MFM is functional modeling language supporting an explicit means-ends intelligent control strategy for large industrial process plants. The model is used...... in several diagnostic experiments analyzing different fault scenarios. The model and results of the experiments are explained and it is shown how MFM based intelligent modeling and automated reasoning can improve the fault diagnosis process significantly....

  1. EAST alternative magnetic configurations: modelling and first experiments

    Science.gov (United States)

    Calabrò, G.; Xiao, B. J.; Chen, S. L.; Duan, Y. M.; Guo, Y.; Li, J. G.; Liu, L.; Luo, Z. P.; Wang, L.; Xu, J.; Zhang, B.; Albanese, R.; Ambrosino, R.; Crisanti, F.; Pericoli Ridolfini, V.; Villone, F.; Viola, B.; Barbato, L.; De Magistris, M.; De Tommasi, G.; Giovannozzi, E.; Mastrostefano, S.; Minucci, S.; Pironti, A.; Ramogida, G.; Tuccillo, A. A.; Zagórski, R.

    2015-08-01

    Heat and particle loads on the plasma facing components are among the most challenging issues to be solved for a reactor design. Alternative magnetic configurations may enable tokamak operation with a lower peak heat load than a standard single null (SN) divertor. This papers reports on the creation and control of one of such alternatives: a two-null nearby divertor configuration. An important element of this study is that this two-null divertor was produced on a large superconducting tokamak as an experimental advanced superconducting tokamak. A preliminary experiment with the second null forming a configuration with significant distance between the two nulls and a contracting geometry near the target plates was performed in 2014. These configurations have been designed using the FIXFREE code and optimized with CREATE-NL tools and are discussed in the paper. Predictive edge simulations using the TECXY code are also presented by comparing the advanced divertor and SN configuration. Finally, the experimental results of ohmic and low confinement (L-mode) two-null divertor and SN discharges and interpretative two-dimensional edge simulations are discussed. Future experiments will be devoted to varying the distance between the two nulls in high confinement (H-mode) discharges.

  2. Channel responses to varying sediment input: A flume experiment modeled after Redwood Creek, California

    Science.gov (United States)

    Madej, M.A.; Sutherland, D.G.; Lisle, T.E.; Pryor, B.

    2009-01-01

    At the reach scale, a channel adjusts to sediment supply and flow through mutual interactions among channel form, bed particle size, and flow dynamics that govern river bed mobility. Sediment can impair the beneficial uses of a river, but the timescales for studying recovery following high sediment loading in the field setting make flume experiments appealing. We use a flume experiment, coupled with field measurements in a gravel-bed river, to explore sediment transport, storage, and mobility relations under various sediment supply conditions. Our flume experiment modeled adjustments of channel morphology, slope, and armoring in a gravel-bed channel. Under moderate sediment increases, channel bed elevation increased and sediment output increased, but channel planform remained similar to pre-feed conditions. During the following degradational cycle, most of the excess sediment was evacuated from the flume and the bed became armored. Under high sediment feed, channel bed elevation increased, the bed became smoother, mid-channel bars and bedload sheets formed, and water surface slope increased. Concurrently, output increased and became more poorly sorted. During the last degradational cycle, the channel became armored and channel incision ceased before all excess sediment was removed. Selective transport of finer material was evident throughout the aggradational cycles and became more pronounced during degradational cycles as the bed became armored. Our flume results of changes in bed elevation, sediment storage, channel morphology, and bed texture parallel those from field surveys of Redwood Creek, northern California, which has exhibited channel bed degradation for 30??years following a large aggradation event in the 1970s. The flume experiment suggested that channel recovery in terms of reestablishing a specific morphology may not occur, but the channel may return to a state of balancing sediment supply and transport capacity.

  3. Elastic scattering of surface plasmon polaritons: Modeling and experiment

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Coello, V.

    1998-01-01

    excitation wavelengths (594 and 633 nm) and different metal (silver and gold) films. The near-field optical images obtained are related to the calculated SPP intensity distributions demonstrating that the model developed can be successfully used in studies of SPP elastic scattering, e.g., to design...

  4. Medical students' emotional development in early clinical experience : a model

    NARCIS (Netherlands)

    Helmich, Esther; Bolhuis, Sanneke; Laan, Roland; Dornan, Tim; Koopmans, Raymond

    Dealing with emotions is a critical feature of professional behaviour. There are no comprehensive theoretical models, however, explaining how medical students learn about emotions. We aimed to explore factors affecting their emotions and how they learn to deal with emotions in themselves and others.

  5. Spectral evaluation of Earth geopotential models and an experiment ...

    Indian Academy of Sciences (India)

    the case study provide a comparison among the EGMs by means of their fit to the local gravity field. 1. Introduction. The gravity field of the ... Compute Restore technique; GNSS/levelling; Turkey; data analysis; modelling. J. Earth Syst. Sci. 121, No. ..... (ΔgFA) (as an approximation of Helmert gravity anomalies) on land were ...

  6. Experience with model based display for advanced diagnostics and control

    International Nuclear Information System (INIS)

    Staffon, J.D.; Lindsay, R.W.

    1989-01-01

    A full color, model based display system based on the Rankine thermodynamic cycle has been developed for use at the Experimental Breeder Reactor II by plant operators, engineers, and experimenters. The displays generate a real time thermodynamic model of the plant processes on computer screens to provide a direct indication of the plant performance. Operators and others who view the displays are no longer required to mentally ''construct'' a model of the process before acting. The model based display accurately depicts the plant states. It appears to effectively reduce the gulf of evaluation, which should result in a significant reduction in human operator errors if this plant display approach is adopted by the nuclear industry. Preliminary comments from users, including operators, indicate an overwhelming acceptance of the display approach. The displays incorporate alarm functions as well as levels of detail ''paging'' capability. The system is developed on a computer network which allows the easy addition of displays as well as extra computers. Constructing a complete console can be rapid and inexpensive. 1 ref., 2 figs

  7. The South African Experience: Beyond the CIDA Model

    Science.gov (United States)

    Bruton, John M.

    2008-01-01

    The Community and Individual Development Association (CIDA) City Campus is presented by Heaton as an innovative African alternative to traditional business education. However, he considers the model in isolation from the unique educational and economic circumstances of postapartheid South Africa. As a response, this article goes beyond the CIDA…

  8. A new adaptive hybrid electromagnetic damper: modelling, optimization, and experiment

    International Nuclear Information System (INIS)

    Asadi, Ehsan; Ribeiro, Roberto; Behrad Khamesee, Mir; Khajepour, Amir

    2015-01-01

    This paper presents the development of a new electromagnetic hybrid damper which provides regenerative adaptive damping force for various applications. Recently, the introduction of electromagnetic technologies to the damping systems has provided researchers with new opportunities for the realization of adaptive semi-active damping systems with the added benefit of energy recovery. In this research, a hybrid electromagnetic damper is proposed. The hybrid damper is configured to operate with viscous and electromagnetic subsystems. The viscous medium provides a bias and fail-safe damping force while the electromagnetic component adds adaptability and the capacity for regeneration to the hybrid design. The electromagnetic component is modeled and analyzed using analytical (lumped equivalent magnetic circuit) and electromagnetic finite element method (FEM) (COMSOL ® software package) approaches. By implementing both modeling approaches, an optimization for the geometric aspects of the electromagnetic subsystem is obtained. Based on the proposed electromagnetic hybrid damping concept and the preliminary optimization solution, a prototype is designed and fabricated. A good agreement is observed between the experimental and FEM results for the magnetic field distribution and electromagnetic damping forces. These results validate the accuracy of the modeling approach and the preliminary optimization solution. An analytical model is also presented for viscous damping force, and is compared with experimental results The results show that the damper is able to produce damping coefficients of 1300 and 0–238 N s m −1 through the viscous and electromagnetic components, respectively. (paper)

  9. Funding models in palliative care: Lessons from international experience.

    Science.gov (United States)

    Groeneveld, E Iris; Cassel, J Brian; Bausewein, Claudia; Csikós, Ágnes; Krajnik, Malgorzata; Ryan, Karen; Haugen, Dagny Faksvåg; Eychmueller, Steffen; Gudat Keller, Heike; Allan, Simon; Hasselaar, Jeroen; García-Baquero Merino, Teresa; Swetenham, Kate; Piper, Kym; Fürst, Carl Johan; Murtagh, Fliss Em

    2017-04-01

    Funding models influence provision and development of palliative care services. As palliative care integrates into mainstream health care provision, opportunities to develop funding mechanisms arise. However, little has been reported on what funding models exist or how we can learn from them. To assess national models and methods for financing and reimbursing palliative care. Initial literature scoping yielded limited evidence on the subject as national policy documents are difficult to identify, access and interpret. We undertook expert consultations to appraise national models of palliative care financing in England, Germany, Hungary, Republic of Ireland, New Zealand, The Netherlands, Norway, Poland, Spain, Sweden, Switzerland, the United States and Wales. These represent different levels of service development and a variety of funding mechanisms. Funding mechanisms reflect country-specific context and local variations in care provision. Patterns emerging include the following: Provider payment is rarely linked to population need and often perpetuates existing inequitable patterns in service provision. Funding is frequently characterised as a mixed system of charitable, public and private payers. The basis on which providers are paid for services rarely reflects individual care input or patient needs. Funding mechanisms need to be well understood and used with caution to ensure best practice and minimise perverse incentives. Before we can conduct cross-national comparisons of costs and impact of palliative care, we need to understand the funding and policy context for palliative care in each country of interest.

  10. Social Modeling Influences on Pain Experience and Behaviour.

    Science.gov (United States)

    Craig, Kenneth D.

    The impact of exposure to social models displaying variably tolerant pain behaviour on observers' expressions of pain is examined. Findings indicate substantial effects on verbal reports of pain, avoidance behaviour, psychophysiological indices, power function parameters, and sensory decision theory indices. Discussion centers on how social models…

  11. Low resistive trasparent conductors with metallic grids : modeling and experiments

    NARCIS (Netherlands)

    Deelen, J. van; Rendering, H.; Mannetje, H.H 't; Klerk, L.; Hovestad, A.

    2012-01-01

    At present, transparent conducting oxides (TCOs) are still superior in performance to most other transparent conductors. Results on opto-electronic modeling and design optimization of TCOs are presented using a monolithically integrated CIGS cell configuration as case. For various cell dimensions

  12. Quantification of fungal growth: models, experiment, and observations

    NARCIS (Netherlands)

    Lamour, A.

    2002-01-01

    This thesis is concerned with the growth of microscopic mycelial fungi (Section I), and that of macroscopic fungi, which form specialised hyphal structures such as rhizomorphs (Section II). A growth model is developed in Section I in relation to soil organic

  13. Experiences with the Capability Maturity Model in a research environment

    NARCIS (Netherlands)

    Velden, van der M.J.; Vreke, J.; Wal, van der B.; Symons, A.

    1996-01-01

    The project described here was aimed at evaluating the Capability Maturity Model (CMM) in the context of a research organization. Part of the evaluation was a standard CMM assessment. It was found that CMM could be applied to a research organization, although its five maturity levels were considered

  14. Early Childhood Educators' Experience of an Alternative Physical Education Model

    Science.gov (United States)

    Tsangaridou, Niki; Genethliou, Nicholas

    2016-01-01

    Alternative instructional and curricular models are regarded as more comprehensive and suitable approaches to providing quality physical education (Kulinna 2008; Lund and Tannehill 2010; McKenzie and Kahan 2008; Metzler 2011; Quay and Peters 2008). The purpose of this study was to describe the impact of the Early Steps Physical Education…

  15. 3D engineered models for highway construction : the Iowa experience.

    Science.gov (United States)

    2015-06-01

    3D engineered modeling is a relatively new and developing technology that can provide numerous bene ts to owners, engineers, : contractors, and the general public. This manual is for highway agencies that are considering or are in the process of s...

  16. Plasticity induced by phase transformation in steel: experiment vs modeling

    International Nuclear Information System (INIS)

    Tahimi, Abdeladhim

    2011-01-01

    The objectives of this work are: (i) understand the mechanisms and phenomena involved in the plasticity of steels in the presence of a diffusive or martensitic phase transformation. (ii) develop tools for predicting TRIP, which are able to correctly reproduce the macroscopic deformation for cases of complex loading and could also provide information about local elasto-visco-plastic interactions between product and parent phases. To this purpose, new experimental tests are conducted on 35NCD16 steel for austenite to martensite transformation and on 100C6 steel for austenite to pearlite transformation. The elasto viscoplastic properties of austenite and pearlite of the 100C6 steel are characterized through tension compression and relaxation tests. The parameters of macro-homogeneous and crystal-based constitutive laws could then be identified such as to analyse different models with respect to the experimental TRIP: the analytical models of Leblond (1989) and Taleb and Sidoroff (2003) but also, above all, different numerical models which can be distinguished by the prevailing assumptions concerning the local kinetics and the constitutive laws. An extension of the single-grain model dedicated to martensitic transformations developed during the thesis of S. Meftah (2007) is proposed. It consists in introducing the polycrystalline character of the austenite through a process of homogenization based on a self-consistent scheme by calculating the properties of an Equivalent Homogeneous Medium environment (EHM). (author)

  17. Performance in model transformations: experiments with ATL and QVT

    NARCIS (Netherlands)

    van Amstel, Marcel; Bosems, S.; Ivanov, Ivan; Ferreira Pires, Luis; Cabot, Jordi; Visser, Eelco

    Model transformations are increasingly being incorporated in software development processes. However, as systems being developed with transformations grow in size and complexity, the performance of the transformations tends to degrade. In this paper we investigate the factors that have an impact on

  18. Complexity effects in choice experiments-based models

    NARCIS (Netherlands)

    Dellaert, B.G.C.; Donkers, B.; van Soest, A.H.O.

    2012-01-01

    Many firms rely on choice experiment–based models to evaluate future marketing actions under various market conditions. This research investigates choice complexity (i.e., number of alternatives, number of attributes, and utility similarity between the most attractive alternatives) and individual

  19. Methane emissions from rice paddies : experiments and modelling

    NARCIS (Netherlands)

    Bodegom, van P.M.

    2000-01-01

    This thesis describes model development and experimentation on the comprehension and prediction of methane (CH 4 ) emissions from rice paddies. The large spatial and temporal variability in CH 4 emissions and the dynamic non-linear relationships

  20. Quark model and high-energy nuclear experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bialas, A.

    1979-05-01

    Theoretical aspects of the measurements of production of low transverse momentum secondaries in high-energy hadron-nucleus and nucleus-nucleus collisions are discussed. Applications of the quark model to those processes are discussed in some detail. 58 references.

  1. Net-erosion profile model and simulation experiments

    International Nuclear Information System (INIS)

    Sagara, Akio

    2001-01-01

    Estimation of net-erosion profile is requisite for evaluating the lifetime of divertor plates under high heat and particle fluxes of fusion plasmas. As a reference in benchmark tests of numerical calculation codes, a self-consistent analytical solution is presented for a simplified divertor condition, wherein the magnetic field line is normal to the target plate and the ionization mean free path of sputtered particles is assumed constant. The primary flux profile of hydrogen and impurities are externally given as well as the return ratio of sputtered atoms to the target. In the direction along the divertor trace, all conditions are uniform. The analytical solution is compared with net-erosion experiments carried out using the Compact Helical System (CHS). The deposition profiles of Ti and O impurities are in very good agreement with the analytical predictions. Recent preliminary results observed on divertor plates in the Large Helical Device (LHD) are briefly presented. (author)

  2. Little Earth Experiment: An instrument to model planetary cores.

    Science.gov (United States)

    Aujogue, Kélig; Pothérat, Alban; Bates, Ian; Debray, François; Sreenivasan, Binod

    2016-08-01

    In this paper, we present a new experimental facility, Little Earth Experiment, designed to study the hydrodynamics of liquid planetary cores. The main novelty of this apparatus is that a transparent electrically conducting electrolyte is subject to extremely high magnetic fields (up to 10 T) to produce electromagnetic effects comparable to those produced by moderate magnetic fields in planetary cores. This technique makes it possible to visualise for the first time the coupling between the principal forces in a convection-driven dynamo by means of Particle Image Velocimetry (PIV) in a geometry relevant to planets. We first present the technology that enables us to generate these forces and implement PIV in a high magnetic field environment. We then show that the magnetic field drastically changes the structure of convective plumes in a configuration relevant to the tangent cylinder region of the Earth's core.

  3. Tunnel fire testing and modeling the Morgex North tunnel experiment

    CERN Document Server

    Borghetti, Fabio; Gandini, Paolo; Frassoldati, Alessio; Tavelli, Silvia

    2017-01-01

    This book aims to cast light on all aspects of tunnel fires, based on experimental activities and theoretical and computational fluid dynamics (CFD) analyses. In particular, the authors describe a transient full-scale fire test (~15 MW), explaining how they designed and performed the experimental activity inside the Morgex North tunnel in Italy. The entire organization of the experiment is described, from preliminary evaluations to the solutions found for management of operational difficulties and safety issues. This fire test allowed the collection of different measurements (temperature, air velocity, smoke composition, pollutant species) useful for validating and improving CFD codes and for testing the real behavior of the tunnel and its safety systems during a diesel oil fire with a significant heat release rate. Finally, the fire dynamics are compared with empirical correlations, CFD simulations, and literature measurements obtained in other similar tunnel fire tests. This book will be of interest to all ...

  4. Synthetic modelling of acoustical propagation applied to seismic oceanography experiments

    Science.gov (United States)

    Kormann, Jean; Cobo, Pedro; Biescas, Berta; Sallarés, Valentí; Papenberg, Cord; Recuero, Manuel; Carbonell, Ramón

    2010-03-01

    Recent work shows that multichannel seismic (MCS) systems provide detailed information on the oceans' finestructure. The aim of this paper is to analyze if high order numerical algorithms are suitable to accurately model the extremely weak wavefield scattered by the oceans' finestructures. For this purpose, we generate synthetic shot records along a coincident seismic and oceanographic profile acquired across a Mediterranean salt lens in the Gulf of Cadiz. We apply a 2D finite-difference time-domain propagation model, together with second-order Complex Frequency Shifted Perfectly Matched Layers at the numerical boundaries, using as reference a realistic sound speed map with the lateral resolution of the seismic data. We show that our numerical propagator creates an acoustical image of the ocean finestructures including the salt lens that reproduces with outstanding detail the real acquired one.

  5. The Significance of the Bystander Effect: Modeling, Experiments, and More Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Brenner, David J.

    2009-07-22

    -term models is needed. As an example of this novel approach, we integrated a stochastic short-term initiation/inactivation/repopulation model with a deterministic two-stage long-term model. Within this new formalism, the following assumptions are implemented: radiation initiates, promotes, or kills pre-malignant cells; a pre-malignant cell generates a clone, which, if it survives, quickly reaches a size limitation; the clone subsequently grows more slowly and can eventually generate a malignant cell; the carcinogenic potential of pre-malignant cells decreases with age. The effectiveness of high-LET radiation per unit dose increases as dose rate decreases. This “inverse dose rate effect” is seen in radon-induced lung carcinogenesis. We suggest a biologically-motivated mechanism based on radiation-induced direct and bystander-effect-related risks: During radon exposure, only a fraction of cells are traversed by alpha particles. These irradiated cells have an increased probability of being initiated into a pre-malignant state. They release signals, which convert some nearby unirradiated cells to an activated state. When already pre-malignant cells are activated, their proliferation (promotion) rate increases. If a radiation dose is sufficient to activate most susceptible cells, protracting the exposure does not substantially decrease the number of activated cells, but prolongs the activated state during which pre-malignant cell proliferation is accelerated. This mechanism is implemented in a low-dose-rate extension of our carcinogenesis model, which integrates both short- and long-term modeling approaches, and was applied to radiotherapy-induced second cancer risk estimation. Model predictions adequately describe the data on radon-induced lung carcinogenesis in humans and rats, using few adjustable parameters. Conclusions about the relative importance of promotion vs. initiation for radon carcinogenesis are similar to those reported with the two-stage clonal expansion model

  6. Blast Load Simulator Experiments for Computational Model Validation Report 3

    Science.gov (United States)

    2017-07-01

    establish confidence in the simulation results specific to their intended use. One method for providing experimental data for computational model...walls, to higher blast pressures required to evaluate the performance of protective construction methods . Figure 1. ERDC Blast Load Simulator (BLS... Instrumentation included 3 pressure gauges mounted on the steel calibration plate, 2 pressure gauges mounted in the wall of the BLS, and 25 pressure gauges

  7. Flooding Experiments and Modeling for Improved Reactor Safety

    International Nuclear Information System (INIS)

    Solmos, M.; Hogan, K.J.; VIerow, K.

    2008-01-01

    Countercurrent two-phase flow and 'flooding' phenomena in light water reactor systems are being investigated experimentally and analytically to improve reactor safety of current and future reactors. The aspects that will be better clarified are the effects of condensation and tube inclination on flooding in large diameter tubes. The current project aims to improve the level of understanding of flooding mechanisms and to develop an analysis model for more accurate evaluations of flooding in the pressurizer surge line of a Pressurized Water Reactor (PWR). Interest in flooding has recently increased because Countercurrent Flow Limitation (CCFL) in the AP600 pressurizer surge line can affect the vessel refill rate following a small break LOCA and because analysis of hypothetical severe accidents with the current flooding models in reactor safety codes shows that these models represent the largest uncertainty in analysis of steam generator tube creep rupture. During a hypothetical station blackout without auxiliary feedwater recovery, should the hot leg become voided, the pressurizer liquid will drain to the hot leg and flooding may occur in the surge line. The flooding model heavily influences the pressurizer emptying rate and the potential for surge line structural failure due to overheating and creep rupture. The air-water test results in vertical tubes are presented in this paper along with a semi-empirical correlation for the onset of flooding. The unique aspects of the study include careful experimentation on large-diameter tubes and an integrated program in which air-water testing provides benchmark knowledge and visualization data from which to conduct steam-water testing

  8. Size exclusion chromatography models and its comparison with experiment

    Czech Academy of Sciences Publication Activity Database

    Netopilík, Miloš

    2017-01-01

    Roč. 8, 4 (Suppl) (2017), s. 29 E-ISSN 2157-7064. [International Conference and Exhibition on Advances in Chromatography & HPLC Techniques /3./. 13.07.2017-14.07.2017, Berlin] R&D Projects: GA ČR(CZ) GC17-04258J Institutional support: RVO:61389013 Keywords : model of separation * flow-rate influence Subject RIV: CD - Macromolecular Chemistry

  9. Vocabulary and Experiences to Develop a Center of Mass Model

    Science.gov (United States)

    Kaar, Taylor; Pollack, Linda B.; Lerner, Michael E.; Engels, Robert J.

    2017-10-01

    The use of systems in many introductory courses is limited and often implicit. Modeling two or more objects as a system and tracking the center of mass of that system is usually not included. Thinking in terms of the center of mass facilitates problem solving while exposing the importance of using conservation laws. We present below three laboratory activities that build this systems thinking for introductory physics students.

  10. Fiber-optical sensor with intensity compensation model in college teaching of physics experiment

    Science.gov (United States)

    Su, Liping; Zhang, Yang; Li, Kun; Zhang, Yu

    2017-08-01

    Optical fiber sensor technology is one of the main contents of modern information technology, which has a very important position in modern science and technology. Fiber optic sensor experiment can improve students' enthusiasm and broaden their horizons in college physics experiment. In this paper the main structure and working principle of fiberoptical sensor with intensity compensation model are introduced. And thus fiber-optical sensor with intensity compensation model is applied to measure micro displacement of Young's modulus measurement experiment and metal linear expansion coefficient measurement experiment in the college physics experiment. Results indicate that the measurement accuracy of micro displacement is higher than that of the traditional methods using fiber-optical sensor with intensity compensation model. Meanwhile this measurement method makes the students understand on the optical fiber, sensor and nature of micro displacement measurement method and makes each experiment strengthen relationship and compatibility, which provides a new idea for the reform of experimental teaching.

  11. Aluminum Laminates in Beverage Packaging: Models and Experiences

    Directory of Open Access Journals (Sweden)

    Gabriella Bolzon

    2015-08-01

    Full Text Available Aluminum laminates are among the main components of beverage packaging. These layered material systems are coupled to paperboard plies except in the cap opening area, where the human force limit sets a requirement on the material properties to allow open-ability and the mechanical characteristics are of particular interest. Experimental investigations have been carried out on this composite and on its components by either traditional or full-field measurement techniques. The interpretation of the collected data has been supported by the simulation of the performed tests considering either a homogenized material model or the individual laminate layers. However, different results may be recovered from similar samples due to physical factors like the material processing route and the embedded defectiveness. In turn, the conclusions may vary depending on the model assumptions. This contribution focuses on the physical effects and on the modeling of the large localized deformation induced by material singularities. This topic is discussed at the light of some experimental results.

  12. Considerations for skin carcinogenesis experiments using inducible transgenic mouse models.

    Science.gov (United States)

    Popis, Martyna C; Wagner, Rebecca E; Constantino-Casas, Fernando; Blanco, Sandra; Frye, Michaela

    2018-01-24

    This study was designed to estimate the percentage of non-malignant skin tumours (papillomas) progressing to malignant squamous cell carcinomas (SCCs) in a carcinogenesis study using established transgenic mouse models. In our skin cancer model, we conditionally induced oncogenic point mutant alleles of p53 and k-ras in undifferentiated, basal cells of the epidermis. Upon activation of the transgenes through administration of tamoxifen, the vast majority of mice (> 80%) developed skin papillomas, yet primarily around the mouth. Since these tumours hindered the mice eating, they rapidly lost weight and needed to be culled before the papillomas progressed to SCCs. The mouth papillomas formed regardless of the route of application, including intraperitoneal injections, local application to the back skin, or subcutaneous insertion of a tamoxifen pellet. Implantation of a slow releasing tamoxifen pellet into 18 mice consistently led to papilloma formation, of which only one progressed to a malignant SCC. Thus, the challenges for skin carcinogenesis studies using this particular cancer mouse model are low conversion rates of papillomas to SCCs and high frequencies of mouth papilloma formation.

  13. Ultrasound assisted synthesis of nanocrystalline zinc oxide: Experiments and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Hosni, Mongia [Laboratoire des Sciences des Procédés et des Matériaux, LSPM-CNRS, Université Paris 13, 99 av. J.B. Clément, 93430 Villetaneuse (France); Farhat, Samir, E-mail: farhat@lspm.cnrs.fr [Laboratoire des Sciences des Procédés et des Matériaux, LSPM-CNRS, Université Paris 13, 99 av. J.B. Clément, 93430 Villetaneuse (France); Schoenstein, Frederic; Karmous, Farah; Jouini, Noureddine [Laboratoire des Sciences des Procédés et des Matériaux, LSPM-CNRS, Université Paris 13, 99 av. J.B. Clément, 93430 Villetaneuse (France); Viana, Bruno [LCMCP Chimie-Paristech, UPMC, Collège de France, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); Mgaidi, Arbi [Laboratoire de chimie minérale industrielle université Tunis el Manar (Tunisia)

    2014-12-05

    Highlights: • ZnO nanospheres and nanowires were grown using ultrasound and thermal activation techniques. • The growth uses forced hydrolysis of zinc acetate in diethylene glycol (DEG). • A thermochemical model was developed based on thermodynamic equilibrium calculations. • We estimate species distribution in the bubble in temperature range from 5000 K to ambient. • We propose a new mechanism for ZnO growth assisted by ultrasound irradiation. - Abstract: A fast and green approach is proposed for the preparation of nanocrystalline zinc oxide (ZnO) via ultrasonic (US) irradiation in polyol medium. The process uses forced hydrolysis of zinc acetate in diethylene glycol (DEG). The protocol is compared to thermal activation under the same chemical environment. The activation method is found to be playing a critical role in the selective synthesis of morphologically distinct nanostructures. As compared to thermally activated conventional polyol process, (US) permits to considerably reduce reaction time as well as size of particles. In addition, the shape of these nanoparticles was changed from long nanowires to small nanospheres, indicating different reaction mechanisms. To explain this difference, a thermochemical model was developed based on thermodynamic equilibrium calculations. The model estimate species distribution in the bubble in temperature range from 5000 K to ambient simulating quenching process during bubble formation and collapse. Our results indicate the presence of high density of zinc atoms that could be responsible of a high density of nucleation as compared to thermal activation.

  14. Pesticide uptake in potatoes: model and field experiments.

    Science.gov (United States)

    Juraske, Ronnie; Vivas, Carmen S Mosquera; Velásquez, Alexander Erazo; Santos, Glenda García; Moreno, Mónica B Berdugo; Gomez, Jaime Diaz; Binder, Claudia R; Hellweg, Stefanie; Dallos, Jairo A Guerrero

    2011-01-15

    A dynamic model for uptake of pesticides in potatoes is presented and evaluated with measurements performed within a field trial in the region of Boyacá, Colombia. The model takes into account the time between pesticide applications and harvest, the time between harvest and consumption, the amount of spray deposition on soil surface, mobility and degradation of pesticide in soil, diffusive uptake and persistence due to crop growth and metabolism in plant material, and loss due to food processing. Food processing steps included were cleaning, washing, storing, and cooking. Pesticide concentrations were measured periodically in soil and potato samples from the beginning of tuber formation until harvest. The model was able to predict the magnitude and temporal profile of the experimentally derived pesticide concentrations well, with all measurements falling within the 90% confidence interval. The fraction of chlorpyrifos applied on the field during plant cultivation that eventually is ingested by the consumer is on average 10(-4)-10(-7), depending on the time between pesticide application and ingestion and the processing step considered.

  15. Ultrasound assisted synthesis of nanocrystalline zinc oxide: Experiments and modelling

    International Nuclear Information System (INIS)

    Hosni, Mongia; Farhat, Samir; Schoenstein, Frederic; Karmous, Farah; Jouini, Noureddine; Viana, Bruno; Mgaidi, Arbi

    2014-01-01

    Highlights: • ZnO nanospheres and nanowires were grown using ultrasound and thermal activation techniques. • The growth uses forced hydrolysis of zinc acetate in diethylene glycol (DEG). • A thermochemical model was developed based on thermodynamic equilibrium calculations. • We estimate species distribution in the bubble in temperature range from 5000 K to ambient. • We propose a new mechanism for ZnO growth assisted by ultrasound irradiation. - Abstract: A fast and green approach is proposed for the preparation of nanocrystalline zinc oxide (ZnO) via ultrasonic (US) irradiation in polyol medium. The process uses forced hydrolysis of zinc acetate in diethylene glycol (DEG). The protocol is compared to thermal activation under the same chemical environment. The activation method is found to be playing a critical role in the selective synthesis of morphologically distinct nanostructures. As compared to thermally activated conventional polyol process, (US) permits to considerably reduce reaction time as well as size of particles. In addition, the shape of these nanoparticles was changed from long nanowires to small nanospheres, indicating different reaction mechanisms. To explain this difference, a thermochemical model was developed based on thermodynamic equilibrium calculations. The model estimate species distribution in the bubble in temperature range from 5000 K to ambient simulating quenching process during bubble formation and collapse. Our results indicate the presence of high density of zinc atoms that could be responsible of a high density of nucleation as compared to thermal activation

  16. An animal model of eating disorders associated with stressful experience in early life.

    Science.gov (United States)

    Jahng, Jeong Won

    2011-02-01

    Experience of childhood abuse is prevalent among patients with eating disorders, and dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis is implicated in its pathophysiology. Neonatal maternal separation is considered as an animal model of stressful experience early in life. Many of studies have demonstrated its impact both on the activity of HPA axis and the development of psycho-emotional disorders later in life. In this paper, a series of our researches on developing an animal model of eating disorders is reviewed. An animal model of neonatal maternal separation was used; Sprague-Dawley pups were separated from dam daily for 180 min during the first 2 weeks of life (MS) or undisturbed. Anxiety-/depression-like behaviors were observed in MS rats at the age of two months with decreased serotonergic activity in the hippocampus and the raphe. Post-weaning social isolation promoted food intake and weight gain of adolescent MS pups, with impacts on anxiety-like behaviors. Sustained hyperphagia was observed in the MS pups subjected to a fasting/refeeding cycle repeatedly during adolescence, with increased plasma corticosterone levels. Anhedonia, major symptom of depression, to palatable food was observed in adolescent MS pups with blunted response of the mesolimbic dopaminergic activity to stress. Results suggest that neonatal maternal separation lead to the development of eating disorders when it is challenged with social or metabolic stressors later in life, in which dysfunctions in the HPA axis and the brain monoaminergic systems may play important roles. Copyright © 2010 Elsevier Inc. All rights reserved.

  17. Flow induced orientation in carbon nanotube suspensions: Modeling and experiments

    Science.gov (United States)

    Natale, Giovanniantonio

    shearing direction were studied. To correlate the microstructure with the rheological data, two different routes were undertaken. The first route involved rheo-optical analysis. Dichroism was investigated for suspensions belonging to the dilute and semi-dilute regimes. Direct information on dispersion, orientation evolution during flow and Brownian motion were obtained. The second route consisted in developing new rheological models in order to correlate micro-scale information to the evolution of the related stress tensor or refractive index tensor. In the dilute regime, the nanotubes were modeled as flexible particles. A modified two-rod model was used, allowing non-straight equilibrium conformations. In more concentrated regimes, the dynamic of the system is controlled by rod-rod interactions. The nanotubes were modeled as inertialess rigid rods and the system orientation state is influenced by interactions via non-linear lubrication forces, hydrodynamic forces and Brownian motion. The comparison of the experimental results with the models predictions allowed to quantify the fundamental mechanisms behind the microstructure evolution of CNT suspensions. To further differentiate the rheology of CNT suspensions, the model predictions were also confronted with the experimental data for a microsize particle suspension: glass fiber-filled polybutene [Sepehr et al. (2004b)]. In the case of the micro-size particles, the model predictions confirmed that the rheological response of the system was controlled by orientation effects while interactions were dominant in the case of CNT suspensions. Hence, this work explores the connections between the bulk rheology of carbon nanotube suspensions and their microstructural evolution. This is the first step towards the design of new processing schemes in order to completely exploit carbon nanotube unique properties.

  18. Modeling and Depletion Simulations for a High Flux Isotope Reactor Cycle with a Representative Experiment Loading

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Betzler, Ben [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Hirtz, Gregory John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Ilas, Germina [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Sunny, Eva [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division

    2016-09-01

    The purpose of this report is to document a high-fidelity VESTA/MCNP High Flux Isotope Reactor (HFIR) core model that features a new, representative experiment loading. This model, which represents the current, high-enriched uranium fuel core, will serve as a reference for low-enriched uranium conversion studies, safety-basis calculations, and other research activities. A new experiment loading model was developed to better represent current, typical experiment loadings, in comparison to the experiment loading included in the model for Cycle 400 (operated in 2004). The new experiment loading model for the flux trap target region includes full length 252Cf production targets, 75Se production capsules, 63Ni production capsules, a 188W production capsule, and various materials irradiation targets. Fully loaded 238Pu production targets are modeled in eleven vertical experiment facilities located in the beryllium reflector. Other changes compared to the Cycle 400 model are the high-fidelity modeling of the fuel element side plates and the material composition of the control elements. Results obtained from the depletion simulations with the new model are presented, with a focus on time-dependent isotopic composition of irradiated fuel and single cycle isotope production metrics.

  19. Utilizing ARC EMCS Seedling Cassettes as Highly Versatile Miniature Growth Chambers for Model Organism Experiments

    Science.gov (United States)

    Freeman, John L.; Steele, Marianne K.; Sun, Gwo-Shing; Heathcote, David; Reinsch, S.; DeSimone, Julia C.; Myers, Zachary A.

    2014-01-01

    The aim of our ground testing was to demonstrate the capability of safely putting specific model organisms into dehydrated stasis, and to later rehydrate and successfully grow them inside flight proven ARC EMCS seedling cassettes. The ARC EMCS seedling cassettes were originally developed to support seedling growth during space flight. The seeds are attached to a solid substrate, launched dry, and then rehydrated in a small volume of media on orbit to initiate the experiment. We hypothesized that the same seedling cassettes should be capable of acting as culture chambers for a wide range of organisms with minimal or no modification. The ability to safely preserve live organisms in a dehydrated state allows for on orbit experiments to be conducted at the best time for crew operations and more importantly provides a tightly controlled physiologically relevant growth experiment with specific environmental parameters. Thus, we performed a series of ground tests that involved growing the organisms, preparing them for dehydration on gridded Polyether Sulfone (PES) membranes, dry storage at ambient temperatures for varying periods of time, followed by rehydration. Inside the culture cassettes, the PES membranes were mounted above blotters containing dehydrated growth media. These were mounted on stainless steel bases and sealed with plastic covers that have permeable membrane covered ports for gas exchange. The results showed we were able to demonstrate acceptable normal growth of C.elegans (nematodes), E.coli (bacteria), S.cerevisiae (yeast), Polytrichum (moss) spores and protonemata, C.thalictroides (fern), D.discoideum (amoeba), and H.dujardini (tardigrades). All organisms showed acceptable growth and rehydration in both petri dishes and culture cassettes initially, and after various time lengths of dehydration. At the end of on orbit ISS European Modular Cultivation System experiments the cassettes could be frozen at ultra-low temperatures, refrigerated, or chemically

  20. Homeostatic role of heterosynaptic plasticity: Models and experiments

    Directory of Open Access Journals (Sweden)

    Marina eChistiakova

    2015-07-01

    Full Text Available Homosynaptic Hebbian-type plasticity provides a cellular mechanism of learning and refinement of connectivity during development in a variety of biological systems. In this review we argue that a complimentary form of plasticity - heterosynaptic plasticity - represents a necessary cellular component for homeostatic regulation of synaptic weights and neuronal activity. The required properties of a homeostatic mechanism which acutely constrains the runaway dynamics imposed by Hebbian associative plasticity have been well-articulated by theoretical and modeling studies. Such mechanism(s should robustly support the stability of operation of neuronal networks and synaptic competition, include changes at non-active synapses, and operate on a similar time scale to Hebbian-type plasticity. The experimentally observed properties of heterosynaptic plasticity have introduced it as a strong candidate to fulfill this homeostatic role. Subsequent modeling studies which incorporate heterosynaptic plasticity into model neurons with Hebbian synapses (utilizing an STDP learning rule have confirmed its ability to robustly provide stability and competition. In contrast, properties of homeostatic synaptic scaling, which is triggered by extreme and long lasting (hours and days changes of neuronal activity, do not fit two crucial requirements for a hypothetical homeostatic mechanism needed to provide stability of operation in the face of on-going synaptic changes driven by Hebbian-type learning rules. Both the trigger and the time scale of homeostatic synaptic scaling are fundamentally different from those of the Hebbian-type plasticity. We conclude that heterosynaptic plasticity, which is triggered by the same episodes of strong postsynaptic activity and operates on the same time scale as Hebbian-type associative plasticity, is ideally suited to serve homeostatic role during on-going synaptic plasticity.

  1. Shear mechanical properties of the spleen: experiment and analytical modelling.

    Science.gov (United States)

    Nicolle, S; Noguer, L; Palierne, J-F

    2012-05-01

    This paper aims at providing the first shear mechanical properties of spleen tissue. Rheometric tests on porcine splenic tissues were performed in the linear and nonlinear regime, revealing a weak frequency dependence of the dynamic moduli in linear regime and a distinct strain-hardening effect in nonlinear regime. These behaviours are typical of soft tissues such as kidney and liver, with however a less pronounced strain-hardening for the spleen. An analytical model based on power laws is then proposed to describe the general shear viscoelastic behaviour of the spleen. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Thermal experiments with LMFBR subassembly models in sodium flow

    International Nuclear Information System (INIS)

    Moeller, R.; Tschoeke, H.

    1982-01-01

    Within the framework of the Fast Breeder Project research work has been undertaken at the Karlsruhe Nuclear Research Center on the thermal and fluid dynamics of nominal and distorted core subassemblies. In 19-rod bundle models (P/D=1.30, W/R=1.38) three-dimensional temperature distributions were measured in the cladding tubes exposed to sodium flow. Results of measurements of the azimuthal temperature profiles of rotated rods in the duct wall zone are indicated for different operating conditions 80 2 , evenly distributed load and oblique load; different axial positions of the spacer grids; and different positions of one bowed rod

  3. Calibration of a finite element composite delamination model by experiments

    DEFF Research Database (Denmark)

    Gaiotti, M.; Rizzo, C.M.; Branner, Kim

    2013-01-01

    This paper deals with the mechanical behavior under in plane compressive loading of thick and mostly unidirectional glass fiber composite plates made with an initial embedded delamination. The delamination is rectangular in shape, causing the separation of the central part of the plate into two...... distinct sub-laminates. The work focuses on experimental validation of a finite element model built using the 9-noded MITC9 shell elements, which prevent locking effects and aiming to capture the highly non linear buckling features involved in the problem. The geometry has been numerically defined...

  4. Arctic pathways of Pacific Water: Arctic Ocean Model Intercomparison experiments.

    Science.gov (United States)

    Aksenov, Yevgeny; Karcher, Michael; Proshutinsky, Andrey; Gerdes, Rüdiger; de Cuevas, Beverly; Golubeva, Elena; Kauker, Frank; Nguyen, An T; Platov, Gennady A; Wadley, Martin; Watanabe, Eiji; Coward, Andrew C; Nurser, A J George

    2016-01-01

    Pacific Water (PW) enters the Arctic Ocean through Bering Strait and brings in heat, fresh water, and nutrients from the northern Bering Sea. The circulation of PW in the central Arctic Ocean is only partially understood due to the lack of observations. In this paper, pathways of PW are investigated using simulations with six state-of-the art regional and global Ocean General Circulation Models (OGCMs). In the simulations, PW is tracked by a passive tracer, released in Bering Strait. Simulated PW spreads from the Bering Strait region in three major branches. One of them starts in the Barrow Canyon, bringing PW along the continental slope of Alaska into the Canadian Straits and then into Baffin Bay. The second begins in the vicinity of the Herald Canyon and transports PW along the continental slope of the East Siberian Sea into the Transpolar Drift, and then through Fram Strait and the Greenland Sea. The third branch begins near the Herald Shoal and the central Chukchi shelf and brings PW into the Beaufort Gyre. In the models, the wind, acting via Ekman pumping, drives the seasonal and interannual variability of PW in the Canadian Basin of the Arctic Ocean. The wind affects the simulated PW pathways by changing the vertical shear of the relative vorticity of the ocean flow in the Canada Basin.

  5. Arctic pathways of Pacific Water: Arctic Ocean Model Intercomparison experiments

    Science.gov (United States)

    Karcher, Michael; Proshutinsky, Andrey; Gerdes, Rüdiger; de Cuevas, Beverly; Golubeva, Elena; Kauker, Frank; Nguyen, An T.; Platov, Gennady A.; Wadley, Martin; Watanabe, Eiji; Coward, Andrew C.; Nurser, A. J. George

    2016-01-01

    Abstract Pacific Water (PW) enters the Arctic Ocean through Bering Strait and brings in heat, fresh water, and nutrients from the northern Bering Sea. The circulation of PW in the central Arctic Ocean is only partially understood due to the lack of observations. In this paper, pathways of PW are investigated using simulations with six state‐of‐the art regional and global Ocean General Circulation Models (OGCMs). In the simulations, PW is tracked by a passive tracer, released in Bering Strait. Simulated PW spreads from the Bering Strait region in three major branches. One of them starts in the Barrow Canyon, bringing PW along the continental slope of Alaska into the Canadian Straits and then into Baffin Bay. The second begins in the vicinity of the Herald Canyon and transports PW along the continental slope of the East Siberian Sea into the Transpolar Drift, and then through Fram Strait and the Greenland Sea. The third branch begins near the Herald Shoal and the central Chukchi shelf and brings PW into the Beaufort Gyre. In the models, the wind, acting via Ekman pumping, drives the seasonal and interannual variability of PW in the Canadian Basin of the Arctic Ocean. The wind affects the simulated PW pathways by changing the vertical shear of the relative vorticity of the ocean flow in the Canada Basin. PMID:27818853

  6. Curing of Thick Thermoset Composite Laminates: Multiphysics Modeling and Experiments

    Science.gov (United States)

    Anandan, S.; Dhaliwal, G. S.; Huo, Z.; Chandrashekhara, K.; Apetre, N.; Iyyer, N.

    2017-11-01

    Fiber reinforced polymer composites are used in high-performance aerospace applications as they are resistant to fatigue, corrosion free and possess high specific strength. The mechanical properties of these composite components depend on the degree of cure and residual stresses developed during the curing process. While these parameters are difficult to determine experimentally in large and complex parts, they can be simulated using numerical models in a cost-effective manner. These simulations can be used to develop cure cycles and change processing parameters to obtain high-quality parts. In the current work, a numerical model was built in Comsol MultiPhysics to simulate the cure behavior of a carbon/epoxy prepreg system (IM7/Cycom 5320-1). A thermal spike was observed in thick laminates when the recommended cure cycle was used. The cure cycle was modified to reduce the thermal spike and maintain the degree of cure at the laminate center. A parametric study was performed to evaluate the effect of air flow in the oven, post cure cycles and cure temperatures on the thermal spike and the resultant degree of cure in the laminate.

  7. ORNL diagnostic and modeling development for LAPD ICRF experiments

    Science.gov (United States)

    Isler, R. C.; Caughman, J. B. O.; Lau, C.; Martin, E. H.; Perkins, R. J.; Compernolle, B. Van; Vincena, S.; Tripathi, S. K. P.; Gekelman, W.

    2017-10-01

    PPPL, UCLA, and ORNL scientists have recently collaborated on a three week ICRF campaign at the upgraded LAPD device to study near field-plasma interactions associated with a single strap antenna driven at 2.38 MHz with 100 kW of RF power. This poster highlights ORNL involvement through implementation of the following diagnostics: an optical emission probe to measure neutral density, a retarding field energy analyzer to measure fast ions, phase locked imaging to measure line integrated RF-driven optical emission fluctuations, and an RF compensated triple Langmuir probe to measure density and temperature. To interpret the results of the experimental campaign a 3D cold plasma finite element model with realistic antenna and vacuum vessel geometry was developed in COMSOL. A summary of these results will be discussed. Highlights include a proof of principle localized and spatially resolved measurement of the neutral density, a strong increase in RF-driven optical emission fluctuations directly in front of the RF antenna strap, a shift in fast ion energies near the plasma edge, and qualitative agreement between the COMSOL cold plasma model with the various diagnostics. Funded by the DOE OFES (DE-AC05-00OR22725, DE-AC02-09CH11466, and DE-FC02-07ER54918) and the Univ. of California (12-LR-237124).

  8. Predictive modeling of liquid-sodium thermal–hydraulics experiments and computations

    International Nuclear Information System (INIS)

    Arslan, Erkan; Cacuci, Dan G.

    2014-01-01

    Highlights: • We applied the predictive modeling method of Cacuci and Ionescu-Bujor (2010). • We assimilated data from sodium flow experiments. • We used computational fluid dynamics simulations of sodium experiments. • The predictive modeling method greatly reduced uncertainties in predicted results. - Abstract: This work applies the predictive modeling procedure formulated by Cacuci and Ionescu-Bujor (2010) to assimilate data from liquid-sodium thermal–hydraulics experiments in order to reduce systematically the uncertainties in the predictions of computational fluid dynamics (CFD) simulations. The predicted CFD-results for the best-estimate model parameters and results describing sodium-flow velocities and temperature distributions are shown to be significantly more precise than the original computations and experiments, in that the predicted uncertainties for the best-estimate results and model parameters are significantly smaller than both the originally computed and the experimental uncertainties

  9. MODELLING CONSUMERS' DEMAND FOR ORGANIC FOOD PRODUCTS: THE SWEDISH EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Manuchehr Irandoust

    2016-07-01

    Full Text Available This paper attempts to examine a few factors characterizing consumer preferences and behavior towards organic food products in the south of Sweden using a proportional odds model which captures the natural ordering of dependent variables and any inherent nonlinearities. The findings show that consumer's choice for organic food depends on perceived benefits of organic food (environment, health, and quality and consumer's perception and attitudes towards labelling system, message framing, and local origin. In addition, high willingness to pay and income level will increase the probability to buy organic food, while the cultural differences and socio-demographic characteristics have no effect on consumer behaviour and attitudes towards organic food products. Policy implications are offered.

  10. Advanced Control of Active Bearings - Modelling, Design and Experiments

    DEFF Research Database (Denmark)

    Theisen, Lukas Roy Svane

    , the enhancement of damping, the extension of operating range and the minimisation of critical vibrations in machine elements are of fundamental importance. The main component to tackle the energy-loss-related problems is the bearing. The area of design of active bearings, while very promising, is still in its...... control design. One example is the controllable radial gas bearing, where the lubricant air is injected through controllable injectors to levitate the rotor on an air film. Feedback control of the injection can improve upon the poor damping to reduce the disturbance sensitivity and vibrations near...... the critical speeds. The feedback control law is preferably designed from a simple model, which captures the dominant dynamics of the machine in the frequency range of interest. This thesis offers two main original contributions in the field of active bearings. First, an experimental technique is proposed...

  11. Recent Advances in Enzymatic Fuel Cells: Experiments and Modeling

    Directory of Open Access Journals (Sweden)

    Ivan Ivanov

    2010-04-01

    Full Text Available Enzymatic fuel cells convert the chemical energy of biofuels into electrical energy. Unlike traditional fuel cell types, which are mainly based on metal catalysts, the enzymatic fuel cells employ enzymes as catalysts. This fuel cell type can be used as an implantable power source for a variety of medical devices used in modern medicine to administer drugs, treat ailments and monitor bodily functions. Some advantages in comparison to conventional fuel cells include a simple fuel cell design and lower cost of the main fuel cell components, however they suffer from severe kinetic limitations mainly due to inefficiency in electron transfer between the enzyme and the electrode surface. In this review article, the major research activities concerned with the enzymatic fuel cells (anode and cathode development, system design, modeling by highlighting the current problems (low cell voltage, low current density, stability will be presented.

  12. Biomechanics of cells and tissues experiments, models and simulations

    CERN Document Server

    2013-01-01

    The application of methodological approaches and mathematical formalisms proper to Physics and Engineering to investigate and describe biological processes and design biological structures has led to the development of many disciplines in the context of computational biology and biotechnology. The best known applicative domain is tissue engineering and its branches. Recent domains of interest are in the field of biophysics, e.g.: multiscale mechanics of biological membranes and films and filaments; multiscale mechanics of adhesion; biomolecular motors and force generation.   Modern hypotheses, models, and tools are currently emerging and resulting from the convergence of the methods and philosophical approaches of the different research areas and disciplines. All these emerging approaches share the purpose of disentangling the complexity of organisms, tissues, and cells and mimicking the function of living systems. The contributions presented in this book are current research highlights of six challenging an...

  13. Experiences Supporting the Lunar Reconnaissance Orbiter Camera: the Devops Model

    Science.gov (United States)

    Licht, A.; Estes, N. M.; Bowman-Cisnesros, E.; Hanger, C. D.

    2013-12-01

    Introduction: The Lunar Reconnaissance Orbiter Camera (LROC) Science Operations Center (SOC) is responsible for instrument targeting, product processing, and archiving [1]. The LROC SOC maintains over 1,000,000 observations with over 300 TB of released data. Processing challenges compound with the acquisition of over 400 Gbits of observations daily creating the need for a robust, efficient, and reliable suite of specialized software. Development Environment: The LROC SOC's software development methodology has evolved over time. Today, the development team operates in close cooperation with the systems administration team in a model known in the IT industry as DevOps. The DevOps model enables a highly productive development environment that facilitates accomplishment of key goals within tight schedules[2]. The LROC SOC DevOps model incorporates industry best practices including prototyping, continuous integration, unit testing, code coverage analysis, version control, and utilizing existing open source software. Scientists and researchers at LROC often prototype algorithms and scripts in a high-level language such as MATLAB or IDL. After the prototype is functionally complete the solution is implemented as production ready software by the developers. Following this process ensures that all controls and requirements set by the LROC SOC DevOps team are met. The LROC SOC also strives to enhance the efficiency of the operations staff by way of weekly presentations and informal mentoring. Many small scripting tasks are assigned to the cognizant operations personnel (end users), allowing for the DevOps team to focus on more complex and mission critical tasks. In addition to leveraging open source software the LROC SOC has also contributed to the open source community by releasing Lunaserv [3]. Findings: The DevOps software model very efficiently provides smooth software releases and maintains team momentum. Scientists prototyping their work has proven to be very efficient

  14. A novel nutrition medicine education model: the Boston University experience.

    Science.gov (United States)

    Lenders, Carine; Gorman, Kathy; Milch, Hannah; Decker, Ashley; Harvey, Nanette; Stanfield, Lorraine; Lim-Miller, Aimee; Salge-Blake, Joan; Judd, Laura; Levine, Sharon

    2013-01-01

    Most deaths in the United States are preventable and related to nutrition. Although physicians are expected to counsel their patients about nutrition-related health conditions, a recent survey reported minimal improvements in nutrition medicine education in US medical schools in the past decade. Starting in 2006, we have developed an educational plan using a novel student-centered model of nutrition medicine education at Boston University School of Medicine that focuses on medical student-mentored extracurricular activities to develop, evaluate, and sustain nutrition medicine education. The medical school uses a team-based approach focusing on case-based learning in the classroom, practice-based learning in the clinical setting, extracurricular activities, and a virtual curriculum to improve medical students' knowledge, attitudes, and practice skills across their 4-y period of training. We have been using objectives from the NIH National Academy Awards guide and tools from the Association of American Medical Colleges to detect new areas of nutrition medicine taught at the medical school. Although we were only able to identify 20.5 h of teaching in the preclerkship years, we observed that most preclerkship nutrition medicine objectives were covered during the course of the 4-y teaching period, and extracurricular activities provided new opportunities for student leadership and partnership with other health professionals. These observations are very encouraging as new assessment tools are being developed. Future plans include further evaluation and dissemination of lessons learned using this model to improve public health wellness with support from academia, government, industry, and foundations.

  15. Model for movement of molten limiter material during the ISX-B beryllium limiter experiment

    International Nuclear Information System (INIS)

    Langley, R.A.; England, A.C.; Edmonds, P.H.; Hogan, J.T.; Neilson, G.H.

    1986-01-01

    A model is proposed for the movement and erosion of limiter material during the Beryllium Limiter Experiment performed on the ISX-B Tokamak. This model is consistent with observed experimental results and plasma operational characteristics. Conclusions drawn from the model can provide an understanding of erosion mechanisms, thereby contributing to the development of future design criteria. (author)

  16. The elastic transfer model of angular rate modulation in F1-ATPase stalling and controlled rotation experiments

    Science.gov (United States)

    Volkán-Kacsó, S.

    2017-06-01

    The recent experimental, theoretical and computational advances in the field of F1-ATPase single-molecule microscopy are briefly surveyed. The role of theory is revealed in the statistical analysis, interpretation and prediction of single-molecule experimental trajectories, and in linking them with atomistic simulations. In particular, a theoretical model of elastically coupled molecular group transfer is reviewed and a detailed method for its application in stalling and controlled rotation experiments is provided. It is shown how the model can predict, using previous experiments, the rates of ligand binding/release processes (steps) and their exponential dependence on rotor angle in these experiments. The concept of Brønsted slopes is reviewed in the context of the single-molecule experiments, and the rate versus rotor angle relations are explained using the elastic model. These experimental data are treated in terms of the effect of thermodynamic driving forces on the rates assuming that the rotor shaft is elastically coupled to stator ring subunits in which the steps occur. In the application of the group transfer model on an extended angular range processes leading up to the transfer are discussed. Implications for large-scale atomistic simulation are suggested for the treatment of torque-generating steps.

  17. The Infertility Experience: Biopsychosocial Effects and Suggestions for Counselors

    Science.gov (United States)

    Watkins, Kathryn J.; Baldo, Tracy D.

    2004-01-01

    Infertility affects many individuals and couples. This article begins with a case study of a couple who have experienced infertility yet do not identify infertility as their presenting problem. Clients and counselors alike often overlook infertility. This article offers an overview of the biology of infertility and its psychological and…

  18. Mobbing Experiences of Instructors: Causes, Results, and Solution Suggestions

    Science.gov (United States)

    Celep, Cevat; Konakli, Tugba

    2013-01-01

    In this study, it was aimed to investigate possible mobbing problems in universities, their causes and results, and to attract attention to precautions that can be taken. Phenomenology as one of the qualitative research methods was used in the study. Sample group of the study was selected through the criteria sampling method and eight instructors…

  19. Radiotherapy of primary human melanomas - experiences and suggestions

    International Nuclear Information System (INIS)

    Elsmann, H.J.; Ernst, K.; Suter, L.

    1991-01-01

    We treated 60 invasive primary human melanomas by soft X-rays. In 23 additional cases radiotherapy was applied after total excision of a primary melanoma. Only in two cases was a tumor observed in the field of irradiation during the follow-up period: A recurrence of a primary melanoma and a skin metastasis. Radioresistance cannot be unequivocally assumed in either case. Since deeply situated in-transit metastases cannot be destroyed by soft X-rays in spite of our good results we regard radiotherapy of invasive primary melanomas as a second choice treatment to be administered if impaired general health, excessive tumor growth in certain localisations or refusal of the patient to not allow a major operation. Nodular parts of primary melanomas should be excised before radiotherapy to obtain material for histopathological confirmation of the diagnosis and to determine the thickness of the tumor. X-rays of lower hardness can subsequently be applied. (orig.) [de

  20. Radiotherapy of primary human melanomas - experiences and suggestions

    Energy Technology Data Exchange (ETDEWEB)

    Elsmann, H.J.; Ernst, K.; Suter, L. (Muenster Univ. (Germany). Fachklinik Hornheide fuer Tumoren, Tuberkulose und Wiederherstellung an Gesicht und Haut)

    1991-07-01

    We treated 60 invasive primary human melanomas by soft X-rays. In 23 additional cases radiotherapy was applied after total excision of a primary melanoma. Only in two cases was a tumor observed in the field of irradiation during the follow-up period: A recurrence of a primary melanoma and a skin metastasis. Radioresistance cannot be unequivocally assumed in either case. Since deeply situated in-transit metastases cannot be destroyed by soft X-rays in spite of our good results we regard radiotherapy of invasive primary melanomas as a second choice treatment to be administered if impaired general health, excessive tumor growth in certain localisations or refusal of the patient to not allow a major operation. Nodular parts of primary melanomas should be excised before radiotherapy to obtain material for histopathological confirmation of the diagnosis and to determine the thickness of the tumor. X-rays of lower hardness can subsequently be applied. (orig.).