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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. Baryogenesis model suggesting antigalaxies

    International Nuclear Information System (INIS)

    Kirilova, D.P.

    1998-12-01

    A non-GUT baryogenesis model, according to which our Universe may contain clusters of antigalaxies is discussed. A mechanism of separation of vast quantities of matter from such of antimatter is described. The provided analysis showed that for a natural range of model parameters a sufficient separation between matter and antimatter regions, required from observational data, can be obtained. (author)

  3. 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...

  4. Do experiments suggest a hierarchy problem?

    International Nuclear Information System (INIS)

    Vissani, F.

    1997-09-01

    The hierarchy problem of the scalar sector of the standard model is reformulated, emphasizing the role of experimental facts that may suggest the existence of a new physics large mass scale, for instance indications of the instability of the matter, or indications in favor of massive neutrinos. In the see-saw model for the neutrino masses a hierarchy problem arises if the mass of the right-handed neutrinos is larger than approximatively 10 7 GeV: this problem, and its possible solutions, are discussed. (author)

  5. Quantitative histological models suggest endothermy in plesiosaurs

    Directory of Open Access Journals (Sweden)

    Corinna V. Fleischle

    2018-06-01

    Full Text Available Background Plesiosaurs are marine reptiles that arose in the Late Triassic and survived to the Late Cretaceous. They have a unique and uniform bauplan and are known for their very long neck and hydrofoil-like flippers. Plesiosaurs are among the most successful vertebrate clades in Earth’s history. Based on bone mass decrease and cosmopolitan distribution, both of which affect lifestyle, indications of parental care, and oxygen isotope analyses, evidence for endothermy in plesiosaurs has accumulated. Recent bone histological investigations also provide evidence of fast growth and elevated metabolic rates. However, quantitative estimations of metabolic rates and bone growth rates in plesiosaurs have not been attempted before. Methods Phylogenetic eigenvector maps is a method for estimating trait values from a predictor variable while taking into account phylogenetic relationships. As predictor variable, this study employs vascular density, measured in bone histological sections of fossil eosauropterygians and extant comparative taxa. We quantified vascular density as primary osteon density, thus, the proportion of vascular area (including lamellar infillings of primary osteons to total bone area. Our response variables are bone growth rate (expressed as local bone apposition rate and resting metabolic rate (RMR. Results Our models reveal bone growth rates and RMRs for plesiosaurs that are in the range of birds, suggesting that plesiosaurs were endotherm. Even for basal eosauropterygians we estimate values in the range of mammals or higher. Discussion Our models are influenced by the availability of comparative data, which are lacking for large marine amniotes, potentially skewing our results. However, our statistically robust inference of fast growth and fast metabolism is in accordance with other evidence for plesiosaurian endothermy. Endothermy may explain the success of plesiosaurs consisting in their survival of the end-Triassic extinction

  6. Some suggestions based on the instrumentation installation experience at RAPP

    International Nuclear Information System (INIS)

    Raghunath, M.R.; Singh, S.; Jain, V.K.

    1977-01-01

    Suggestions regarding installation of reactor instrumentation have been made based on the instrumentation installation experience at the Rajasthan Atomic Power Plant. It has been mentioned that the instrumentation installation work has to proceed simultaneously with that of the heavy equipment and piping errection work, to meet the commissioning target dates. (S.K.K.)

  7. 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)

  8. Suggestion of Islamic Insurance Company Model

    OpenAIRE

    Abdullah Ibrahim Nazal

    2015-01-01

    This study is one of very few studies which have investigated Islamic Insurance Companies as solution. It explained its operations also comparing with Traditional Insurance Companies and theoretical Islamic insurance models. As result to this study Islamic Insurance companies are profit organization. It helps Islamic banks but it costs customer to face expect risk. Islamic Insurance companies have many ways to get profits and consider all customers installments grants. Its operation gap comes...

  9. 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.

  10. 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

  11. 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.)

  12. The Effects of Repeated Experience on Children's Suggestibility.

    Science.gov (United States)

    Powell, Martine B.; Roberts, Kim P.; Ceci, Stephen J.; Hembrooke, Helene

    1999-01-01

    Examined effect of suggestive questions on 3- to 5-year-olds' and 6- to 8-year-olds' recall of the final occurrence of repeated event. Found that relative to reports of children experiencing single occurrence, reports about fixed items of repeated events were less contaminated by false suggestions. Children's age and delay of interview were…

  13. 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)

  14. 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.

  15. My Teaching Experience With Navajo College Students, Writing Anxiety, Contrastive Rhetoric, and Some Suggestions

    Directory of Open Access Journals (Sweden)

    Yi-Wen Huang

    2015-08-01

    Full Text Available This article analyzes factors that might be associated with Navajo college students’ writing anxiety. Oral tradition, reading, syntax, and past experience are the factors discussed. Suggestions based on previous literature and personal experience are provided.

  16. Sustainable Competitive Advantage for Educational Institutions: A Suggested Model.

    Science.gov (United States)

    Mazzarol, Tim; Soutar, Geoffrey Norman

    1999-01-01

    Outlines a model of factors critical to establishing and maintaining sustainable competitive advantage for education-services enterprises in international markets. The model, which combines industrial economics, management theory, and services marketing, seeks to explain the strategic decision-making environment in which the education exporter…

  17. Is the dissociative adult suggestible? A test of the trauma and fantasy models of dissociation.

    Science.gov (United States)

    Kluemper, Nicole S; Dalenberg, Constance

    2014-01-01

    Psychologists have long assumed a connection between traumatic experience and psychological dissociation. This hypothesis is referred to as the trauma model of dissociation. In the past decade, a series of papers have been published that question this traditional causal link, proposing an alternative fantasy model of dissociation. In the present research, the relationship among dissociation, suggestibility, and fantasy proneness was examined. Suggestibility was measured through the Gudjonsson Scale of Interrogative Suggestibility (GSS) as well as an autobiographically based version of this measure based on the events of September 11, 2001. Consistent with prior research and with the trauma model, dissociation correlated positively with trauma severity (r = .32, p suggestibility measure. Although some participants did become quite emotional during the procedure, the risk/benefit ratio was perceived by almost all participants to be positive, with more reactive individuals evaluating the procedure more positively. The results consistently support the trauma model of dissociation and fail to support the fantasy model of dissociation.

  18. 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...

  19. 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.

  20. Suggestibility, Social Support, and Memory for a Novel Experience in Young Children

    Science.gov (United States)

    Quas, J.A.; Wallin, A.R.; Papini, S.; Lench, H.; Scullin, M.H.

    2005-01-01

    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…

  1. Does the Nature of the Experience Influence Suggestibility? A Study of Children's Event Memory.

    Science.gov (United States)

    Gobbo, Camilla; Mega, Carolina; Pipe, Margaret-Ellen

    2002-01-01

    Two experiments examined effects of event modality on young children's memory and suggestibility. Findings indicated that 5-year-olds were more accurate than 3-year-olds and those participating in the event were more accurate than those either observing or listening to a narrative. Assessment method, level of event learning, delay to testing, and…

  2. 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…

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

    Science.gov (United States)

    Ryan, Kaitlin F; Gauthier, Isabel

    2016-12-01

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. 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.

  5. 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.

  6. Accidents on board merchant ships. Suggestions based on Centro Internazionale Radio Medico (CIRM) experience.

    Science.gov (United States)

    Napoleone, Paolo

    2016-01-01

    This statistical study was performed to find out the occurrence of accidents on board ships assisted by Centro Internazionale Radio Medico (CIRM) during the years 2010-2015, with the aim of providing suggestions in accident prevention, based on such a wide experience. The case histories of CIRM in the years 2010-2015 were examined. The total number of accidents per year was calculated and compared as a percentage with the total number of cases assisted by CIRM per year. The incidence of accidents on board in these years ranged between 14.4% and 18.4% of total cases assisted per year, which is constantly increasing. The most common injuries on board among cases treated by CIRM were contusions and wounds. Also burns and eye injuries were significantly represented. Multiple injuries and head injuries were found to be the most frequent cause of death on board due to an accident. More information on the occurrence and type of accidents and on the body injured areas should represent the basis for developing strategies and campaigns for their prevention.

  7. 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

  8. 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

  9. 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.

  10. Experience moderates overlap between object and face recognition, suggesting a common ability.

    Science.gov (United States)

    Gauthier, Isabel; McGugin, Rankin W; Richler, Jennifer J; Herzmann, Grit; Speegle, Magen; Van Gulick, Ana E

    2014-07-03

    Some research finds that face recognition is largely independent from the recognition of other objects; a specialized and innate ability to recognize faces could therefore have little or nothing to do with our ability to recognize objects. We propose a new framework in which recognition performance for any category is the product of domain-general ability and category-specific experience. In Experiment 1, we show that the overlap between face and object recognition depends on experience with objects. In 256 subjects we measured face recognition, object recognition for eight categories, and self-reported experience with these categories. Experience predicted neither face recognition nor object recognition but moderated their relationship: Face recognition performance is increasingly similar to object recognition performance with increasing object experience. If a subject has a lot of experience with objects and is found to perform poorly, they also prove to have a low ability with faces. In a follow-up survey, we explored the dimensions of experience with objects that may have contributed to self-reported experience in Experiment 1. Different dimensions of experience appear to be more salient for different categories, with general self-reports of expertise reflecting judgments of verbal knowledge about a category more than judgments of visual performance. The complexity of experience and current limitations in its measurement support the importance of aggregating across multiple categories. Our findings imply that both face and object recognition are supported by a common, domain-general ability expressed through experience with a category and best measured when accounting for experience. © 2014 ARVO.

  11. 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

  12. 78 FR 73518 - Notice Inviting Suggestions for New Experiments for the Experimental Sites Initiative; Federal...

    Science.gov (United States)

    2013-12-06

    ... postsecondary educational institutions participating in one or more of eight on- going experiments. Information... program accountability. Institutions and others, including businesses, philanthropies, and State agencies... Federal Regulations is available via the Federal Digital System at: www.gpo.gov/fdsys . At this site you...

  13. 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

  14. 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.)

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

    OpenAIRE

    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 t...

  16. Magnetization rotation or generation of incoherent spin waves? Suggestions for a spin-transfer effect experiment

    International Nuclear Information System (INIS)

    Bazaliy, Y. B.; Jones, B. A.

    2002-01-01

    ''Spin-transfer'' torque is created when electric current is passed through metallic ferromagnets and may have interesting applications in spintronics. So far it was experimentally studied in ''collinear'' geometries, where it is difficult to predict whether magnetization will coherently rotate or spin-waves will be generated. Here we propose an easy modification of existing experiment in which the spin-polarization of incoming current will no longer be collinear with magnetization and recalculate the switching behavior of the device. We expect that a better agreement with the magnetization rotation theory will be achieved. That can be an important step in reconciling alternative points of view on the effect of spin-transfer torque

  17. Caudal dysgenesis and sirenomelia-single centre experience suggests common pathogenic basis.

    Science.gov (United States)

    Thottungal, Anjana D; Charles, Adrian K; Dickinson, Jan E; Bower, Carol

    2010-10-01

    Abnormally formed lower limbs with varying degrees of fusion are the major feature of sirenomelia whereas maldeveloped lower limbs without fusion are found in association with caudal dysgenesis (CD). The relationship between these two entities has been a topic of debate for many years. The presence of a single umbilical artery originating from the abdominal aorta was considered a major feature distinguishing sirenomelia from CD. Based on this finding, the vascular steal theory was put forward as the causative mechanism of sirenomelia. CD and sirenomelia were considered to be two entirely different entities with distinct pathogenic mechanisms. However, it is now clear that a single umbilical artery can be found in some patients of CD and normal umbilical arteries in some patients of sirenomelia. The hypothesis of primary deficiency of caudal mesoderm caused by early developmental disruption suggests that sirenomelia and CD are two ends of a spectrum of maldevelopment of caudal mesoderm. In this paper we report on the clinical and pathological features of 16 patients of CD and 9 patients of sirenomelia from our institution and review the literature. This series of cases is notable for the significant association with neural tube defects, refining the renal and urogenital pathology associated with these conditions, and supporting the concept of a continuum of the disease spectrum. Copyright © 2010 Wiley-Liss, Inc.

  18. 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

  19. 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.

  20. 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...

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Model selection approach suggests causal association between 25-hydroxyvitamin D and colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Lina Zgaga

    Full Text Available Vitamin D deficiency has been associated with increased risk of colorectal cancer (CRC, but causal relationship has not yet been confirmed. We investigate the direction of causation between vitamin D and CRC by extending the conventional approaches to allow pleiotropic relationships and by explicitly modelling unmeasured confounders.Plasma 25-hydroxyvitamin D (25-OHD, genetic variants associated with 25-OHD and CRC, and other relevant information was available for 2645 individuals (1057 CRC cases and 1588 controls and included in the model. We investigate whether 25-OHD is likely to be causally associated with CRC, or vice versa, by selecting the best modelling hypothesis according to Bayesian predictive scores. We examine consistency for a range of prior assumptions.Model comparison showed preference for the causal association between low 25-OHD and CRC over the reverse causal hypothesis. This was confirmed for posterior mean deviances obtained for both models (11.5 natural log units in favour of the causal model, and also for deviance information criteria (DIC computed for a range of prior distributions. Overall, models ignoring hidden confounding or pleiotropy had significantly poorer DIC scores.Results suggest causal association between 25-OHD and colorectal cancer, and support the need for randomised clinical trials for further confirmations.

  6. 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

  7. 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

    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 the ozone-temperature correlation for the summer of 2010 and to analyze its sensitivity to precursor emissions and meteorology by using the regional air quality model, the Comprehensive Air Quality Model with Extensions (CAMx). The results show that the model significantly underestimates the observed high afternoon surface ozone mixing ratios (≥ 60 ppb) by 10-20 ppb and overestimates the lower ones (degradation of the model performance for the lower ozone mixing ratios. The model performance for ozone-temperature correlation is also better when NOx emissions are doubled. In the Benelux area, however, the third scenario (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

  8. A computational model of the LGI1 protein suggests a common binding site for ADAM proteins.

    Directory of Open Access Journals (Sweden)

    Emanuela Leonardi

    Full Text Available Mutations of human leucine-rich glioma inactivated (LGI1 gene encoding the epitempin protein cause autosomal dominant temporal lateral epilepsy (ADTLE, a rare familial partial epileptic syndrome. The LGI1 gene seems to have a role on the transmission of neuronal messages but the exact molecular mechanism remains unclear. In contrast to other genes involved in epileptic disorders, epitempin shows no homology with known ion channel genes but contains two domains, composed of repeated structural units, known to mediate protein-protein interactions.A three dimensional in silico model of the two epitempin domains was built to predict the structure-function relationship and propose a functional model integrating previous experimental findings. Conserved and electrostatic charged regions of the model surface suggest a possible arrangement between the two domains and identifies a possible ADAM protein binding site in the β-propeller domain and another protein binding site in the leucine-rich repeat domain. The functional model indicates that epitempin could mediate the interaction between proteins localized to different synaptic sides in a static way, by forming a dimer, or in a dynamic way, by binding proteins at different times.The model was also used to predict effects of known disease-causing missense mutations. Most of the variants are predicted to alter protein folding while several other map to functional surface regions. In agreement with experimental evidence, this suggests that non-secreted LGI1 mutants could be retained within the cell by quality control mechanisms or by altering interactions required for the secretion process.

  9. Sensed presence and mystical experiences are predicted by suggestibility, not by the application of transcranial weak complex magnetic fields.

    Science.gov (United States)

    Granqvist, Pehr; Fredrikson, Mats; Unge, Patrik; Hagenfeldt, Andrea; Valind, Sven; Larhammar, Dan; Larsson, Marcus

    2005-04-29

    Transcranial magnetic stimulation (TMS) with weak (micro Tesla) complex waveform fields have been claimed to evoke the sensed presence of a sentient being in up to 80% in the general population. These findings have had a questionable neurophysiological foundation as the fields are approximately six orders of magnitude weaker than ordinary TMS fields. Also, no independent replication has been reported. To replicate and extend previous findings, we performed a double-blind experiment (N=89), with a sham-field control group. Personality characteristics indicating suggestibility (absorption, signs of abnormal temporal lobe activity, and a "new age"-lifestyle orientation) were used as predictors. Sensed presence, mystical, and other somatosensory experiences previously reported from the magnetic field stimulation were outcome measures. We found no evidence for any effects of the magnetic fields, neither in the entire group, nor in individuals high in suggestibility. Because the personality characteristics significantly predicted outcomes, suggestibility may account for previously reported effects. Our results strongly question the earlier claims of experiential effects of weak magnetic fields.

  10. 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

  11. Seclusion and restraint in psychiatry: patients' experiences and practical suggestions on how to improve practices and use alternatives.

    Science.gov (United States)

    Kontio, Raija; Joffe, Grigori; Putkonen, Hanna; Kuosmanen, Lauri; Hane, Kimmo; Holi, Matti; Välimäki, Maritta

    2012-01-01

    This study explored psychiatric inpatients' experiences of, and their suggestions for, improvement of seclusion/restraint, and alternatives to their use in Finland. The data were collected by focused interviews (n= 30) and were analyzed with inductive content analysis. Patients' perspectives received insufficient attention during seclusion/restraint processes. Improvements (e.g., humane treatment) and alternatives (e.g., empathetic patient-staff interaction) to seclusion/restraint, as suggested by the patients, focused on essential parts of nursing practice but have not been largely adopted. Patients' basic needs have to be met, and patient-staff interaction has to also continue during seclusion/restraint. Providing patients with meaningful activities, planning beforehand, documenting the patients' wishes, and making patient-staff agreements reduce the need for restrictions and offer alternatives for seclusion/restraint. Service users must be involved in all practical development. © 2011 Wiley Periodicals, Inc.

  12. Mathematical representation of bolted-joint stiffness: A new suggested model

    Energy Technology Data Exchange (ETDEWEB)

    Haidar, Nawras; Obeed, Salwan; Jawad, Mohamed [College of Engineering, University of Babylon, Babel (Iraq)

    2011-11-15

    Joint member stiffness in a bolted connection directly influences the safety of a design in regard to both static and fatigue loading, as well as in the prevention of separation in the connection. This work provides a new simple model for computing the member stiffness in bolted connections for both fully and partially developed stress envelope fields. The new model is built using a stress distribution polynomial of third order. Finite element analysis (FEA) is performed for some joints geometries, and the results are used to estimate the best analytical envelope angle in the proposed analytical model that gives suitable convergence between the compared results. An experimental effort is exerted to validate the accuracy of a suggested model. When analytical results are compared with FEA results and experimental data, the maximum absolute percentage errors are found to be 2.69 and 14.69, respectively. Also, a good agreement is obtained when the analytical results are compared with other researchers' results.

  13. 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.

  14. 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.

  15. A normalization model suggests that attention changes the weighting of inputs between visual areas.

    Science.gov (United States)

    Ruff, Douglas A; Cohen, Marlene R

    2017-05-16

    Models of divisive normalization can explain the trial-averaged responses of neurons in sensory, association, and motor areas under a wide range of conditions, including how visual attention changes the gains of neurons in visual cortex. Attention, like other modulatory processes, is also associated with changes in the extent to which pairs of neurons share trial-to-trial variability. We showed recently that in addition to decreasing correlations between similarly tuned neurons within the same visual area, attention increases correlations between neurons in primary visual cortex (V1) and the middle temporal area (MT) and that an extension of a classic normalization model can account for this correlation increase. One of the benefits of having a descriptive model that can account for many physiological observations is that it can be used to probe the mechanisms underlying processes such as attention. Here, we use electrical microstimulation in V1 paired with recording in MT to provide causal evidence that the relationship between V1 and MT activity is nonlinear and is well described by divisive normalization. We then use the normalization model and recording and microstimulation experiments to show that the attention dependence of V1-MT correlations is better explained by a mechanism in which attention changes the weights of connections between V1 and MT than by a mechanism that modulates responses in either area. Our study shows that normalization can explain interactions between neurons in different areas and provides a framework for using multiarea recording and stimulation to probe the neural mechanisms underlying neuronal computations.

  16. The 'model omnitron' proposed experiment

    International Nuclear Information System (INIS)

    Sestero, A.

    1997-05-01

    The Model Omitron is a compact tokamak experiment which is designed by the Fusion Engineering Unit of ENEA and CITIF CONSORTIUM. The building of Model Omitron would allow for full testing of Omitron engineering, and partial testing of Omitron physics -at about 1/20 of the cost that has been estimated for the larger parent machine. In particular, due to the unusually large ohmic power densities (up to 100 times the nominal value in the Frascati FTU experiment), in Model Omitron the radial energy flux is reaching values comparable or higher than envisaged of the larger ignition experiments Omitron, Ignitor and Iter. Consequently, conditions are expected to occur at the plasma border in the scrape-off layer of Model Omitron, which are representative of the quoted larger experiments. Moreover, since all this will occur under ohmic heating alone, one will hopefully be able to derive an energy transport model fo the ohmic heating regime that is valid over a range of plasma parameters (in particular, of the temperature parameter) wider than it was possible before. In the Model Omitron experiment, finally - by reducing the plasma current and/or the toroidal field down to, say, 1/3 or 1/4 of the nominal values -additional topics can be tackled, such as: large safety-factor configurations (of interest for improving confinement), large aspect-ratio configurations (of interest for the investigation of advanced concepts in tokamaks), high beta (with RF heating -also of interest for the investigation of advanced concepts in tokamaks), long pulse discharges (of interest for demonstrating stationary conditions in the current profile)

  17. Modeling of glycerol-3-phosphate transporter suggests a potential 'tilt' mechanism involved in its function.

    Science.gov (United States)

    Tsigelny, Igor F; Greenberg, Jerry; Kouznetsova, Valentina; Nigam, Sanjay K

    2008-10-01

    Many major facilitator superfamily (MFS) transporters have similar 12-transmembrane alpha-helical topologies with two six-helix halves connected by a long loop. In humans, these transporters participate in key physiological processes and are also, as in the case of members of the organic anion transporter (OAT) family, of pharmaceutical interest. Recently, crystal structures of two bacterial representatives of the MFS family--the glycerol-3-phosphate transporter (GlpT) and lac-permease (LacY)--have been solved and, because of assumptions regarding the high structural conservation of this family, there is hope that the results can be applied to mammalian transporters as well. Based on crystallography, it has been suggested that a major conformational "switching" mechanism accounts for ligand transport by MFS proteins. This conformational switch would then allow periodic changes in the overall transporter configuration, resulting in its cyclic opening to the periplasm or cytoplasm. Following this lead, we have modeled a possible "switch" mechanism in GlpT, using the concept of rotation of protein domains as in the DynDom program17 and membranephilic constraints predicted by the MAPAS program.(23) We found that the minima of energies of intersubunit interactions support two alternate positions consistent with their transport properties. Thus, for GlpT, a "tilt" of 9 degrees -10 degrees rotation had the most favorable energetics of electrostatic interaction between the two halves of the transporter; moreover, this confirmation was sufficient to suggest transport of the ligand across the membrane. We conducted steered molecular dynamics simulations of the GlpT-ligand system to explore how glycerol-3-phosphate would be handled by the "tilted" structure, and obtained results generally consistent with experimental mutagenesis data. While biochemical data remain most consistent with a single-site alternating access model, our results raise the possibility that, while the

  18. 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.

  19. 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.

  20. 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.

  1. Mobbing call experiment suggests the enhancement of forest bird movement by tree cover in urban landscapes across seasons

    Directory of Open Access Journals (Sweden)

    Atsushi Shimazaki

    2017-06-01

    Full Text Available Local scale movement behavior is an important basis to predict large-scale bird movements in heterogeneous landscapes. Here we conducted playback experiments using mobbing calls to estimate the probability that forest birds would cross a 50-m urban area during three seasons (breeding, dispersal, and wintering seasons with varying amounts of tree cover, building area, and electric wire density. We examined the responses of four forest resident species: Marsh Tit (Poecile palustris, Varied Tit (Sittiparus varius, Japanese Tit (P. minor, and Eurasian Nuthatch (Sitta europaea in central Hokkaido, northern Japan. We carried out and analyzed 250 playback experiments that attracted 618 individuals. Our results showed that tree cover increased the crossing probability of three species other than Varied Tit. Building area and electric wire density had no detectable effect on crossing probability for four species. Seasonal difference in the crossing probability was found only for Varied Tit, and the probability was the highest in the breeding season. These results suggest that the positive effect of tree cover on the crossing probability would be consistent across seasons. We therefore conclude that planting trees would be an effective way to promote forest bird movement within an urban landscape.

  2. 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.

  3. 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.

  4. Metabolomics analysis and modeling suggest a lysophosphocholines-PAF receptor interaction in fibromyalgia.

    Directory of Open Access Journals (Sweden)

    Pierluigi Caboni

    Full Text Available Fibromyalgia Syndrome (FMS is a chronic disease characterized by widespread pain, and difficult to diagnose and treat. We analyzed the plasma metabolic profile of patients with FMS by using a metabolomics approach combining Liquid Chromatography-Quadrupole-Time Of Flight/Mass Spectrometry (LC-Q-TOF/MS with multivariate statistical analysis, aiming to discriminate patients and controls. LC-Q-TOF/MS analysis of plasma (FMS patients: n = 22 and controls: n = 21 identified many lipid compounds, mainly lysophosphocholines (lysoPCs, phosphocholines and ceramides. Multivariate statistical analysis was performed to identify the discriminating metabolites. A protein docking and molecular dynamic (MD study was then performed, using the most discriminating lysoPCs, to validate the binding to Platelet Activating Factor (1-alkyl-2-acetyl-sn-glycero-3-phosphocholine, PAF Receptor (PAFr. Discriminating metabolites between FMS patients and controls were identified as 1-tetradecanoyl-sn-glycero-3-phosphocholine [PC(14:0/0:0] and 1-hexadecanoyl-sn-glycero-3-phosphocholine [PC(16:0/0:0]. MD and docking indicate that the ligands investigated have similar potentialities to activate the PAFr receptor. The application of a metabolomic approach discriminated FMS patients from controls, with an over-representation of PC(14:0/0:0 and PC(16:0/0:0 compounds in the metabolic profiles. These results and the modeling of metabolite-PAFr interaction, allowed us to hypothesize that lipids oxidative fragmentation might generate lysoPCs in abundance, that in turn will act as PAF-like bioactivators. Overall results suggest disease biomarkers and potential therapeutical targets for FMS.

  5. 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.

  6. 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.

  7. 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.

  8. Bridging experiments, models and simulations

    DEFF Research Database (Denmark)

    Carusi, Annamaria; Burrage, Kevin; Rodríguez, Blanca

    2012-01-01

    Computational models in physiology often integrate functional and structural information from a large range of spatiotemporal scales from the ionic to the whole organ level. Their sophistication raises both expectations and skepticism concerning how computational methods can improve our...... 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...... 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....

  9. 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

  10. Predictor Relationships between Values Held by Married Individuals, Resilience and Conflict Resolution Styles: A Model Suggestion

    Science.gov (United States)

    Tosun, Fatma; Dilmac, Bulent

    2015-01-01

    The aim of the present research is to reveal the predictor relationships between the values held by married individuals, resilience and conflict resolution styles. The research adopts a relational screening model that is a sub-type of the general screening model. The sample of the research consists of 375 married individuals, of which 173 are…

  11. 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,…

  12. Comparing Satellite Rainfall Estimates with Rain-Gauge Data: Optimal Strategies Suggested by a Spectral Model

    Science.gov (United States)

    Bell, Thomas L.; Kundu, Prasun K.; Lau, William K. M. (Technical Monitor)

    2002-01-01

    Validation of satellite remote-sensing methods for estimating rainfall against rain-gauge data is attractive because of the direct nature of the rain-gauge measurements. Comparisons of satellite estimates to rain-gauge data are difficult, however, because of the extreme variability of rain and the fact that satellites view large areas over a short time while rain gauges monitor small areas continuously. In this paper, a statistical model of rainfall variability developed for studies of sampling error in averages of satellite data is used to examine the impact of spatial and temporal averaging of satellite and gauge data on intercomparison results. The model parameters were derived from radar observations of rain, but the model appears to capture many of the characteristics of rain-gauge data as well. The model predicts that many months of data from areas containing a few gauges are required to validate satellite estimates over the areas, and that the areas should be of the order of several hundred km in diameter. Over gauge arrays of sufficiently high density, the optimal areas and averaging times are reduced. The possibility of using time-weighted averages of gauge data is explored.

  13. 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.

  14. A dynamical stabilizer in the climate system: a mechanism suggested by a simple model

    Science.gov (United States)

    Bates, J. R.

    1999-05-01

    A simple zonally averaged hemispheric model of the climate system is constructed, based on energy equations for two ocean basins separated at 30° latitude with the surface fluxes calculated explicitly. A combination of empirical input and theoretical calculation is used to determine an annual mean equilibrium climate for the model and to study its stability with respect to small perturbations. The insolation, the mean albedos and the equilibrium temperatures for the two model zones are prescribed from observation. The principal agent of interaction between the zones is the vertically integrated poleward transport of atmospheric angular momentum across their common boundary. This is parameterized using an empirical formula derived from a multiyear atmospheric data set. The surface winds are derived from the angular momentum transport assuming the atmosphere to be in a state of dynamic balance on the climatic timescales of interest. A further assumption that the air sea temperature difference and low level relative humidity remain fixed at their mean observed values then allows the surface fluxes of latent and sensible heat to be calculated. Results from a radiative model, which show a positive lower tropospheric water vapour/infrared radiative feedback on SST perturbations in both zones, are used to calculate the net upward infrared radiative fluxes at the surface. In the model's equilibrium climate, the principal processes balancing the solar radiation absorbed at the surface are evaporation in the tropical zone and net infrared radiation in the extratropical zone. The stability of small perturbations about the equilibrium is studied using a linearized form of the ocean energy equations. Ice-albedo and cloud feedbacks are omitted and attention is focussed on the competing effects of the water vapour/infrared radiative feedback and the turbulent surface flux and oceanic heat transport feedbacks associated with the angular momentum cycle. The perturbation equations

  15. 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

  16. 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.

  17. 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.

  18. Spectroscopic imaging of the pilocarpine model of human epilepsy suggests that early NAA reduction predicts epilepsy.

    Science.gov (United States)

    Gomes, W A; Lado, F A; de Lanerolle, N C; Takahashi, K; Pan, C; Hetherington, H P

    2007-08-01

    Reduced hippocampal N-acetyl aspartate (NAA) is commonly observed in patients with advanced, chronic temporal lobe epilepsy (TLE). It is unclear, however, whether an NAA deficit is also present during the clinically quiescent latent period that characterizes early TLE. This question has important implications for the use of MR spectroscopic imaging (MRSI) in the early identification of patients at risk for TLE. To determine whether NAA is diminished during the latent period, we obtained high-resolution (1)H spectroscopic imaging during the latent period of the rat pilocarpine model of human TLE. We used actively detuneable surface reception and volume transmission coils to enhance sensitivity and a semiautomated voxel shifting method to accurately position voxels within the hippocampi. During the latent period, 2 and 7 d following pilocarpine treatment, hippocampal NAA was significantly reduced by 27.5 +/- 6.9% (P NAA deficit is not due to neuron loss and therefore likely represents metabolic impairment of hippocampal neurons during the latent phase. Therefore, spectroscopic imaging provides an early marker for metabolic dysfunction in this model of TLE.

  19. 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.

  20. Evaluation of the white finger risk prediction model in ISO 5349 suggests need for prospective studies.

    Science.gov (United States)

    Gemne, G; Lundström, R

    1996-05-01

    The risk prediction model for white fingers in Annex A of ISO 5349 is not likely to offer protection from all tools and all work processes. It is also probable that some work place changes it has initiated are either redundant or lack the intended effect. The main reasons for these shortcomings are the following. The often demonstrated disagreement between predicted and observed white fingers occurrence may be related to the fact that the model is based on latency data. This leads to an overestimation, to an unknown extent, of true group risks. A possible healthy worker effect, resulting in underestimation, has not been considered, and uncertainty because of recall bias is connected with using latency as effect variable in a slowly developing disorder like white fingers. The diagnostic criteria for white fingers have varied over the years, causing a possible inclusion of circulatory disturbances other than those induced by vibration. Among insufficiently clarified matters unrelated to vibration are variations in individual susceptibility and other host factors that modify vibration effects, uncertainty concerning daily or total effective exposure, and the fact that variation in work methods and processes as well as ergonomic factors other than vibration tend to make different groups incomparable form the viewpoint of risk of injury. Lack of sufficient data on vibration measurements and employment durations add to the uncertainty, as do variations in tool conditions (grinder wheels, etc) and inherent difficulties in measurement. Finally, the ISO 5349 frequency-weighting curve only relates to acute sensory effects rather than chronic effects on vascular functions like white fingers, and directional difference in sensitivity has not been incorporated in the curve. Data on exposure-response relationships are needed from prospective studies that monitor the dose of exposure to special vibration types and all relevant environmental agents, employ diagnostics with good

  1. 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)

  2. Data assimilation and model evaluation experiment datasets

    Science.gov (United States)

    Lai, Chung-Cheng A.; Qian, Wen; Glenn, Scott M.

    1994-01-01

    The Institute for Naval Oceanography, in cooperation with Naval Research Laboratories and universities, executed the Data Assimilation and Model Evaluation Experiment (DAMEE) for the Gulf Stream region during fiscal years 1991-1993. Enormous effort has gone into the preparation of several high-quality and consistent datasets for model initialization and verification. This paper describes the preparation process, the temporal and spatial scopes, the contents, the structure, etc., of these datasets. The goal of DAMEE and the need of data for the four phases of experiment are briefly stated. The preparation of DAMEE datasets consisted of a series of processes: (1) collection of observational data; (2) analysis and interpretation; (3) interpolation using the Optimum Thermal Interpolation System package; (4) quality control and re-analysis; and (5) data archiving and software documentation. The data products from these processes included a time series of 3D fields of temperature and salinity, 2D fields of surface dynamic height and mixed-layer depth, analysis of the Gulf Stream and rings system, and bathythermograph profiles. To date, these are the most detailed and high-quality data for mesoscale ocean modeling, data assimilation, and forecasting research. Feedback from ocean modeling groups who tested this data was incorporated into its refinement. Suggestions for DAMEE data usages include (1) ocean modeling and data assimilation studies, (2) diagnosis and theoretical studies, and (3) comparisons with locally detailed observations.

  3. Model of a Generic Natural Uranium Conversion Plant ? Suggested Measures to Strengthen International Safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Raffo-Caiado, Ana Claudia [ORNL; Begovich, John M [ORNL; Ferrada, Juan J [ORNL

    2009-11-01

    This is the final report that closed a joint collaboration effort between DOE and the National Nuclear Energy Commission of Brazil (CNEN). In 2005, DOE and CNEN started a collaborative effort to evaluate measures that can strengthen the effectiveness of international safeguards at a natural uranium conversion plant (NUCP). The work was performed by DOE s Oak Ridge National Laboratory and CNEN. A generic model of a NUCP was developed and typical processing steps were defined. Advanced instrumentation and techniques for verification purposes were identified and investigated. The scope of the work was triggered by the International Atomic Energy Agency s 2003 revised policy concerning the starting point of safeguards at uranium conversion facilities. Prior to this policy only the final products of the uranium conversion plant were considered to be of composition and purity suitable for use in the nuclear fuel cycle and therefore, subject to the IAEA safeguards control. DOE and CNEN have explored options for implementing the IAEA policy, although Brazil understands that the new policy established by the IAEA is beyond the framework of the Quadripartite Agreement of which it is one of the parties, together with Argentina, the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC) and the IAEA. Two technical papers on this subject were published at the 2005 and 2008 INMM Annual Meetings.

  4. A link between mitotic entry and membrane growth suggests a novel model for cell size control.

    Science.gov (United States)

    Anastasia, Steph D; Nguyen, Duy Linh; Thai, Vu; Meloy, Melissa; MacDonough, Tracy; Kellogg, Douglas R

    2012-04-02

    Addition of new membrane to the cell surface by membrane trafficking is necessary for cell growth. In this paper, we report that blocking membrane traffic causes a mitotic checkpoint arrest via Wee1-dependent inhibitory phosphorylation of Cdk1. Checkpoint signals are relayed by the Rho1 GTPase, protein kinase C (Pkc1), and a specific form of protein phosphatase 2A (PP2A(Cdc55)). Signaling via this pathway is dependent on membrane traffic and appears to increase gradually during polar bud growth. We hypothesize that delivery of vesicles to the site of bud growth generates a signal that is proportional to the extent of polarized membrane growth and that the strength of the signal is read by downstream components to determine when sufficient growth has occurred for initiation of mitosis. Growth-dependent signaling could explain how membrane growth is integrated with cell cycle progression. It could also control both cell size and morphogenesis, thereby reconciling divergent models for mitotic checkpoint function.

  5. 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

  6. 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...

  7. Taiwan experience suggests that RhD typing for blood transfusion is unnecessary in southeast Asian populations.

    Science.gov (United States)

    Lin, Marie

    2006-01-01

    The high frequency of RhD (D) antigen among Taiwanese persons (99.67%) often imposes unnecessary risks of under-transfusion on D- patients awaiting D- blood. Also because of the rare occurrence of anti-D among Taiwanese persons, routine pretransfusion D typing has been discontinued in the Mackay Memorial Hospital since 1988. This report is the retrospective evaluation of the outcome of abolishing RhD typing for Taiwanese. More than 10 years of alloantibody data at Mackay Memorial Hospital Blood Bank were reviewed. The cases with anti-D were further used to analyze the potency of D antigen and to observe whether there were differences in the incidence of anti-D before and after discontinuation of routine D typing among Taiwanese individuals. The incidence of anti-D before and after discontinuation of routine pretransfusion D typing has remained unchanged. The immunogenicity of D and "Mi(a)" in Taiwanese persons is found to be similar. In terms of opportunity for immunization, however, the "Mi(a)" antigen (phenotype frequency 7.3% in Taiwanese persons) has become the most important blood group antigen in Taiwan. The results strongly support the exclusion of D typing from routine compatibility testing for individuals of Taiwanese origin. Because the low incidence of D- and relatively high incidence of "Mi(a)"+ phenotypes are common findings throughout southeast Asia, and because a population genetic study revealed that the Taiwanese people are genetically related to southern Asian populations, it is suggested that RhD typing for blood transfusion is unnecessary among southeast Asian populations.

  8. Mouse model for Usher syndrome: linkage mapping suggests homology to Usher type I reported at human chromosome 11p15.

    OpenAIRE

    Heckenlively, J R; Chang, B; Erway, L C; Peng, C; Hawes, N L; Hageman, G S; Roderick, T H

    1995-01-01

    Usher syndrome is a group of diseases with autosomal recessive inheritance, congenital hearing loss, and the development of retinitis pigmentosa, a progressive retinal degeneration characterized by night blindness and visual field loss over several decades. The causes of Usher syndrome are unknown and no animal models have been available for study. Four human gene sites have been reported, suggesting at least four separate forms of Usher syndrome. We report a mouse model of type I Usher syndr...

  9. Modeling of microgravity combustion experiments

    Science.gov (United States)

    Buckmaster, John

    1995-01-01

    This program started in February 1991, and is designed to improve our understanding of basic combustion phenomena by the modeling of various configurations undergoing experimental study by others. Results through 1992 were reported in the second workshop. Work since that time has examined the following topics: Flame-balls; Intrinsic and acoustic instabilities in multiphase mixtures; Radiation effects in premixed combustion; Smouldering, both forward and reverse, as well as two dimensional smoulder.

  10. Model of CSR Induced Bursts in Slicing Experiments

    International Nuclear Information System (INIS)

    Stupakov, G.; Heifets, S.

    2006-01-01

    We suggest a model describing the CSR bursts observed in recent experiments at the Advanced Light Source at the LBL. The model is based on the linear theory of the CSR instability in electron rings. We describe how an initial perturbation of the beam generated by the laser pulse evolves in time when the beam is unstable due to the CSR wakefield

  11. Quantitative modeling of clinical, cellular, and extracellular matrix variables suggest prognostic indicators in cancer: a model in neuroblastoma.

    Science.gov (United States)

    Tadeo, Irene; Piqueras, Marta; Montaner, David; Villamón, Eva; Berbegall, Ana P; Cañete, Adela; Navarro, Samuel; Noguera, Rosa

    2014-02-01

    Risk classification and treatment stratification for cancer patients is restricted by our incomplete picture of the complex and unknown interactions between the patient's organism and tumor tissues (transformed cells supported by tumor stroma). Moreover, all clinical factors and laboratory studies used to indicate treatment effectiveness and outcomes are by their nature a simplification of the biological system of cancer, and cannot yet incorporate all possible prognostic indicators. A multiparametric analysis on 184 tumor cylinders was performed. To highlight the benefit of integrating digitized medical imaging into this field, we present the results of computational studies carried out on quantitative measurements, taken from stromal and cancer cells and various extracellular matrix fibers interpenetrated by glycosaminoglycans, and eight current approaches to risk stratification systems in patients with primary and nonprimary neuroblastoma. New tumor tissue indicators from both fields, the cellular and the extracellular elements, emerge as reliable prognostic markers for risk stratification and could be used as molecular targets of specific therapies. The key to dealing with personalized therapy lies in the mathematical modeling. The use of bioinformatics in patient-tumor-microenvironment data management allows a predictive model in neuroblastoma.

  12. Experience economy meets business model design

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...

  13. 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

  14. 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.

  15. 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

  16. 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 J; Potter, Kevin M; Hipkins, Valerie D

    2018-03-14

    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

  17. An interactive activation and competition model of person knowledge, suggested by proactive interference by traits spontaneously inferred from behaviours.

    Science.gov (United States)

    Wang, Yuanbo E; Higgins, Nancy C; Uleman, James S; Michaux, Aaron; Vipond, Douglas

    2016-03-01

    People unconsciously and unintentionally make inferences about others' personality traits based on their behaviours. In this study, a classic memory phenomenon--proactive interference (PI)--is for the first time used to detect spontaneous trait inferences. PI should occur when lists of behaviour descriptions, all implying the same trait, are to be remembered. Switching to a new trait should produce 'release' from proactive interference (or RPI). Results from two experiments supported these predictions. PI and RPI effects are consistent with an interactive activation and competition model of person perception (e.g., McNeill & Burton, 2002, J. Exp. Psychol., 55A, 1141), which predicts categorical organization of social behaviours based on personality traits. Advantages of this model are discussed. © 2015 The British Psychological Society.

  18. 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.

  19. Modeling experiments using quantum and Kolmogorov probability

    International Nuclear Information System (INIS)

    Hess, Karl

    2008-01-01

    Criteria are presented that permit a straightforward partition of experiments into sets that can be modeled using both quantum probability and the classical probability framework of Kolmogorov. These new criteria concentrate on the operational aspects of the experiments and lead beyond the commonly appreciated partition by relating experiments to commuting and non-commuting quantum operators as well as non-entangled and entangled wavefunctions. In other words the space of experiments that can be understood using classical probability is larger than usually assumed. This knowledge provides advantages for areas such as nanoscience and engineering or quantum computation.

  20. 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...

  1. 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

    2016-09-13

    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.

  2. 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.

  3. 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.

  4. 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.

  5. Extracting Models in Single Molecule Experiments

    Science.gov (United States)

    Presse, Steve

    2013-03-01

    Single molecule experiments can now monitor the journey of a protein from its assembly near a ribosome to its proteolytic demise. Ideally all single molecule data should be self-explanatory. However data originating from single molecule experiments is particularly challenging to interpret on account of fluctuations and noise at such small scales. Realistically, basic understanding comes from models carefully extracted from the noisy data. Statistical mechanics, and maximum entropy in particular, provide a powerful framework for accomplishing this task in a principled fashion. Here I will discuss our work in extracting conformational memory from single molecule force spectroscopy experiments on large biomolecules. One clear advantage of this method is that we let the data tend towards the correct model, we do not fit the data. I will show that the dynamical model of the single molecule dynamics which emerges from this analysis is often more textured and complex than could otherwise come from fitting the data to a pre-conceived model.

  6. 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.

  7. 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)

  8. Modeling of Glycerol-3-Phosphate Transporter Suggests a Potential ‘Tilt’ Mechanism involved in its Function

    Science.gov (United States)

    Tsigelny, Igor F.; Greenberg, Jerry; Kouznetsova, Valentina; Nigam, Sanjay K.

    2009-01-01

    Many major facilitator superfamily (MFS) transporters have similar 12-transmembrane α-helical topologies with two six-helix halves connected by a long loop. In humans, these transporters participate in key physiological processes and are also, as in the case of members of the organic anion transporter (OAT) family, of pharmaceutical interest. Recently, crystal structures of two bacterial representatives of the MFS family — the glycerol-3-phosphate transporter (GlpT) and lac-permease (LacY) — have been solved and, because of assumptions regarding the high structural conservation of this family, there is hope that the results can be applied to mammalian transporters as well. Based on crystallography, it has been suggested that a major conformational “switching” mechanism accounts for ligand transport by MFS proteins. This conformational switch would then allow periodic changes in the overall transporter configuration, resulting in its cyclic opening to the periplasm or cytoplasm. Following this lead, we have modeled a possible “switch” mechanism in GlpT, using the concept of rotation of protein domains as in the DynDom program17 and membranephilic constraints predicted by the MAPAS program.23 We found that the minima of energies of intersubunit interactions support two alternate positions consistent with their transport properties. Thus, for GlpT, a “tilt” of 9°–10° rotation had the most favorable energetics of electrostatic interaction between the two halves of the transporter; moreover, this confirmation was sufficient to suggest transport of the ligand across the membrane. We conducted steered molecular dynamics simulations of the GlpT-ligand system to explore how glycerol-3-phosphate would be handled by the “tilted” structure, and obtained results generally consistent with experimental mutagenesis data. While biochemical data remain most consistent with a single-site alternating access model, our results raise the possibility that, while

  9. Refining Grasp Affordance Models by Experience

    DEFF Research Database (Denmark)

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

    2010-01-01

    We present a method for learning object grasp affordance models in 3D from experience, and demonstrate its applicability through extensive testing and evaluation on a realistic and largely autonomous platform. Grasp affordance refers here to relative object-gripper configurations that yield stable...... 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...... is bootstrapped with a grasp density formed from visual cues. We show that the robot effectively applies its experience by downweighting poor grasp solutions, which results in increased success rates at subsequent learning cycles. We also present success rates in a practical scenario where a robot needs...

  10. Increasing organic C and N fluxes from a northern Boreal river basin - monitoring and modelling suggest climate related controls

    Science.gov (United States)

    Lepistö, A.; Futter, M.; Kortelainen, P.

    2012-04-01

    Increasing trends in total organic carbon (TOC) concentrations in lakes and streams across northern Europe and North America have been reported. Various hypotheses including enhanced decomposition of organic soils, changes in hydrology and flow paths, decreased acid deposition and land use changes have been put forward to explain the widespread occurrence of this phenomenon. Both observational and modelling studies are needed to identify the most important drivers and relevant processes controlling observed trends in TOC concentrations. Typically, TOC concentrations in Finnish rivers and lakes are high. The Simojoki river basin (3160 km2) is located in the northern Boreal zone of Finland and experiences low, declining sulphate deposition and limited other human impacts. Forest harvest, land drainage and ditch maintenance are the main land management activities in the catchment. Long-term changes (30-40 years) and seasonal trends of total organic nitrogen (TON) and carbon (TOC) concentrations and fluxes in the Simojoki river system were studied. Concentrations of TOC and TON increased particularly during high flows. TOC concentrations are slowly but continuously increasing, fluctuating between droughts and wet periods. The highest concentrations were detected in 1998-2000 during a period of very high flows, after the drought period 1994-1997. Trends in concentrations of TOC and TON in Simojoki were not linked to declines in sulphate deposition but were more related to trends in climate and hydrology. The autumn season is particularly sensitive to climate change impacts. The INCA-C model was applied to simulate TOC dynamics in the catchment. Model results showed that climate change driven patterns in runoff and soil moisture and soil temperature were more important than temporal patterns of sulphate deposition and land management in controlling surface water TOC concentrations. The possible factors behind changes of TOC and TON concentrations and increasing fluxes to

  11. Lattice-based model of ductal carcinoma in situ suggests rules for breast cancer progression to an invasive state.

    Directory of Open Access Journals (Sweden)

    Eline Boghaert

    2014-12-01

    Full Text Available Ductal carcinoma in situ (DCIS is a heterogeneous group of non-invasive lesions of the breast that result from abnormal proliferation of mammary epithelial cells. Pathologists characterize DCIS by four tissue morphologies (micropapillary, cribriform, solid, and comedo, but the underlying mechanisms that distinguish the development and progression of these morphologies are not well understood. Here we explored the conditions leading to the emergence of the different morphologies of DCIS using a two-dimensional multi-cell lattice-based model that incorporates cell proliferation, apoptosis, necrosis, adhesion, and contractility. We found that the relative rates of cell proliferation and apoptosis governed which of the four morphologies emerged. High proliferation and low apoptosis favored the emergence of solid and comedo morphologies. In contrast, low proliferation and high apoptosis led to the micropapillary morphology, whereas high proliferation and high apoptosis led to the cribriform morphology. The natural progression between morphologies cannot be investigated in vivo since lesions are usually surgically removed upon detection; however, our model suggests probable transitions between these morphologies during breast cancer progression. Importantly, cribriform and comedo appear to be the ultimate morphologies of DCIS. Motivated by previous experimental studies demonstrating that tumor cells behave differently depending on where they are located within the mammary duct in vivo or in engineered tissues, we examined the effects of tissue geometry on the progression of DCIS. In agreement with our previous experimental work, we found that cells are more likely to invade from the end of ducts and that this preferential invasion is regulated by cell adhesion and contractility. This model provides additional insight into tumor cell behavior and allows the exploration of phenotypic transitions not easily monitored in vivo.

  12. Lattice-based model of ductal carcinoma in situ suggests rules for breast cancer progression to an invasive state.

    Science.gov (United States)

    Boghaert, Eline; Radisky, Derek C; Nelson, Celeste M

    2014-12-01

    Ductal carcinoma in situ (DCIS) is a heterogeneous group of non-invasive lesions of the breast that result from abnormal proliferation of mammary epithelial cells. Pathologists characterize DCIS by four tissue morphologies (micropapillary, cribriform, solid, and comedo), but the underlying mechanisms that distinguish the development and progression of these morphologies are not well understood. Here we explored the conditions leading to the emergence of the different morphologies of DCIS using a two-dimensional multi-cell lattice-based model that incorporates cell proliferation, apoptosis, necrosis, adhesion, and contractility. We found that the relative rates of cell proliferation and apoptosis governed which of the four morphologies emerged. High proliferation and low apoptosis favored the emergence of solid and comedo morphologies. In contrast, low proliferation and high apoptosis led to the micropapillary morphology, whereas high proliferation and high apoptosis led to the cribriform morphology. The natural progression between morphologies cannot be investigated in vivo since lesions are usually surgically removed upon detection; however, our model suggests probable transitions between these morphologies during breast cancer progression. Importantly, cribriform and comedo appear to be the ultimate morphologies of DCIS. Motivated by previous experimental studies demonstrating that tumor cells behave differently depending on where they are located within the mammary duct in vivo or in engineered tissues, we examined the effects of tissue geometry on the progression of DCIS. In agreement with our previous experimental work, we found that cells are more likely to invade from the end of ducts and that this preferential invasion is regulated by cell adhesion and contractility. This model provides additional insight into tumor cell behavior and allows the exploration of phenotypic transitions not easily monitored in vivo.

  13. Rapid genome reshaping by multiple-gene loss after whole-genome duplication in teleost fish suggested by mathematical modeling

    Science.gov (United States)

    Sato, Yukuto; Tsukamoto, Katsumi; Nishida, Mutsumi

    2015-01-01

    Whole-genome duplication (WGD) is believed to be a significant source of major evolutionary innovation. Redundant genes resulting from WGD are thought to be lost or acquire new functions. However, the rates of gene loss and thus temporal process of genome reshaping after WGD remain unclear. The WGD shared by all teleost fish, one-half of all jawed vertebrates, was more recent than the two ancient WGDs that occurred before the origin of jawed vertebrates, and thus lends itself to analysis of gene loss and genome reshaping. Using a newly developed orthology identification pipeline, we inferred the post–teleost-specific WGD evolutionary histories of 6,892 protein-coding genes from nine phylogenetically representative teleost genomes on a time-calibrated tree. We found that rapid gene loss did occur in the first 60 My, with a loss of more than 70–80% of duplicated genes, and produced similar genomic gene arrangements within teleosts in that relatively short time. Mathematical modeling suggests that rapid gene loss occurred mainly by events involving simultaneous loss of multiple genes. We found that the subsequent 250 My were characterized by slow and steady loss of individual genes. Our pipeline also identified about 1,100 shared single-copy genes that are inferred to have become singletons before the divergence of clupeocephalan teleosts. Therefore, our comparative genome analysis suggests that rapid gene loss just after the WGD reshaped teleost genomes before the major divergence, and provides a useful set of marker genes for future phylogenetic analysis. PMID:26578810

  14. Zebrafish models of BAG3 myofibrillar myopathy suggest a toxic gain of function leading to BAG3 insufficiency.

    Science.gov (United States)

    Ruparelia, Avnika A; Oorschot, Viola; Vaz, Raquel; Ramm, Georg; Bryson-Richardson, Robert J

    2014-12-01

    Mutations in the co-chaperone Bcl2-associated athanogene 3 (BAG3) can cause myofibrillar myopathy (MFM), a childhood-onset progressive muscle disease, characterized by the formation of protein aggregates and myofibrillar disintegration. In contrast to other MFM-causing proteins, BAG3 has no direct structural role, but regulates autophagy and the degradation of misfolded proteins. To investigate the mechanism of disease in BAG3-related MFM, we expressed wild-type BAG3 or the dominant MFM-causing BAG3 (BAG3(P209L)) in zebrafish. Expression of the mutant protein results in the formation of aggregates that contain wild-type BAG3. Through the stimulation and inhibition of autophagy, we tested the prevailing hypothesis that impaired autophagic function is responsible for the formation of protein aggregates. Contrary to the existing theory, our studies reveal that inhibition of autophagy is not sufficient to induce protein aggregation. Expression of the mutant protein, however, did not induce myofibrillar disintegration and we therefore examined the effect of knocking down Bag3 function. Loss of Bag3 resulted in myofibrillar disintegration, but not in the formation of protein aggregates. Remarkably, BAG3(P209L) is able to rescue the myofibrillar disintegration phenotype, further demonstrating that its function is not impaired. Together, our knockdown and overexpression experiments identify a mechanism whereby BAG3(P209L) aggregates form, gradually reducing the pool of available BAG3, which eventually results in BAG3 insufficiency and myofibrillar disintegration. This mechanism is consistent with the childhood onset and progressive nature of MFM and suggests that reducing aggregation through enhanced degradation or inhibition of nucleation would be an effective therapy for this disease.

  15. Cooling tower plume - model and experiment

    Science.gov (United States)

    Cizek, Jan; Gemperle, Jiri; Strob, Miroslav; Nozicka, Jiri

    The paper discusses the description of the simple model of the, so-called, steam plume, which in many cases forms during the operation of the evaporative cooling systems of the power plants, or large technological units. The model is based on semi-empirical equations that describe the behaviour of a mixture of two gases in case of the free jet stream. In the conclusion of the paper, a simple experiment is presented through which the results of the designed model shall be validated in the subsequent period.

  16. Cooling tower plume - model and experiment

    Directory of Open Access Journals (Sweden)

    Cizek Jan

    2017-01-01

    Full Text Available The paper discusses the description of the simple model of the, so-called, steam plume, which in many cases forms during the operation of the evaporative cooling systems of the power plants, or large technological units. The model is based on semi-empirical equations that describe the behaviour of a mixture of two gases in case of the free jet stream. In the conclusion of the paper, a simple experiment is presented through which the results of the designed model shall be validated in the subsequent period.

  17. Retrospective analysis of the quality of reports by author-suggested and non-author-suggested reviewers in journals operating on open or single-blind peer review models.

    Science.gov (United States)

    Kowalczuk, Maria K; Dudbridge, Frank; Nanda, Shreeya; Harriman, Stephanie L; Patel, Jigisha; Moylan, Elizabeth C

    2015-09-29

    To assess whether reports from reviewers recommended by authors show a bias in quality and recommendation for editorial decision, compared with reviewers suggested by other parties, and whether reviewer reports for journals operating on open or single-blind peer review models differ with regard to report quality and reviewer recommendations. Retrospective analysis of the quality of reviewer reports using an established Review Quality Instrument, and analysis of reviewer recommendations and author satisfaction surveys. BioMed Central biology and medical journals. BMC Infectious Diseases and BMC Microbiology are similar in size, rejection rates, impact factors and editorial processes, but the former uses open peer review while the latter uses single-blind peer review. The Journal of Inflammation has operated under both peer review models. Two hundred reviewer reports submitted to BMC Infectious Diseases, 200 reviewer reports submitted to BMC Microbiology and 400 reviewer reports submitted to the Journal of Inflammation. For each journal, author-suggested reviewers provided reports of comparable quality to non-author-suggested reviewers, but were significantly more likely to recommend acceptance, irrespective of the peer review model (previewer reports measured by the Review Quality Instrument was 5% higher than for BMC Microbiology (p=0.042). For the Journal of Inflammation, the quality of reports was the same irrespective of the peer review model used. Reviewers suggested by authors provide reports of comparable quality to non-author-suggested reviewers, but are significantly more likely to recommend acceptance. Open peer review reports for BMC Infectious Diseases were of higher quality than single-blind reports for BMC Microbiology. There was no difference in quality of peer review in the Journal of Inflammation under open peer review compared with single blind. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a

  18. 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

  19. 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.

  20. 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

  1. 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...

  2. Thermal experiments in the ADS target model

    International Nuclear Information System (INIS)

    Efanov, A.D.; Orlov, Yu.I.; Sorokin, A.P.; Ivanov, E.F.; Bogoslovskaya, G.P.; Li, N.

    2002-01-01

    Experiments on the development of the target heat model project and method of investigation into heat exchange in target were conducted with the aim of analysis of thermomechanical and strength characteristics of device; experimental data on the temperature distribution in coolant and membrane were obtained. Obtained data demonstrate that the temperature heterogeneity of membrane and coolant are connected with the temperature distribution variability near the membrane. Peculiarities of the experiment are noted: maximal temperature of oscillations at high point of the membrane, and power bearing temperature oscillations in the range 0 - 1 Hz [ru

  3. Modeling the Nab Experiment Electronics in SPICE

    Science.gov (United States)

    Blose, Alexander; Crawford, Christopher; Sprow, Aaron; Nab Collaboration

    2017-09-01

    The goal of the Nab experiment is to measure the neutron decay coefficients a, the electron-neutrino correlation, as well as b, the Fierz interference term to precisely test the Standard Model, as well as probe for Beyond the Standard Model physics. In this experiment, protons from the beta decay of the neutron are guided through a magnetic field into a Silicon detector. Event reconstruction will be achieved via time-of-flight measurement for the proton and direct measurement of the coincident electron energy in highly segmented silicon detectors, so the amplification circuitry needs to preserve fast timing, provide good amplitude resolution, and be packaged in a high-density format. We have designed a SPICE simulation to model the full electronics chain for the Nab experiment in order to understand the contributions of each stage and optimize them for performance. Additionally, analytic solutions to each of the components have been determined where available. We will present a comparison of the output from the SPICE model, analytic solution, and empirically determined data.

  4. Some major problems with existing models and terminology associated with kimberlite pipes from a volcanological perspective, and some suggestions

    Science.gov (United States)

    Cas, R. A. F.; Hayman, P.; Pittari, A.; Porritt, L.

    2008-06-01

    have a more factual, descriptive basis, but are still inadequately documented given the recency of their discovery. The diversity amongst kimberlite bodies suggests that a three-model classification is an over-simplification. Every kimberlite is altered to varying degrees, which is an intrinsic consequence of the ultrabasic composition of kimberlite and the in-vent context; few preserve original textures. The effects of syn- to post-emplacement alteration on original textures have not been adequately considered to date, and should be back-stripped to identify original textural elements and configurations. Applying sedimentological textural configurations as a guide to emplacement processes would be useful. The traditional terminology has many connotations about spatial position in pipe and of process. Perhaps the traditional terminology can be retained in the industrial situation as a general lithofacies-mining terminological scheme because it is so entrenched. However, for research purposes a more descriptive lithofacies terminology should be adopted to facilitate detailed understanding of deposit characteristics, important variations in these, and the process origins. For example every deposit of TKB is different in componentry, texture, or depositional structure. However, because so many deposits in many different pipes are called TKB, there is an implication that they are all similar and that similar processes were involved, which is far from clear.

  5. Modeling Hemispheric Detonation Experiments in 2-Dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Howard, W M; Fried, L E; Vitello, P A; Druce, R L; Phillips, D; Lee, R; Mudge, S; Roeske, F

    2006-06-22

    Experiments have been performed with LX-17 (92.5% TATB and 7.5% Kel-F 800 binder) to study scaling of detonation waves using a dimensional scaling in a hemispherical divergent geometry. We model these experiments using an arbitrary Lagrange-Eulerian (ALE3D) hydrodynamics code, with reactive flow models based on the thermo-chemical code, Cheetah. The thermo-chemical code Cheetah provides a pressure-dependent kinetic rate law, along with an equation of state based on exponential-6 fluid potentials for individual detonation product species, calibrated to high pressures ({approx} few Mbars) and high temperatures (20000K). The parameters for these potentials are fit to a wide variety of experimental data, including shock, compression and sound speed data. For the un-reacted high explosive equation of state we use a modified Murnaghan form. We model the detonator (including the flyer plate) and initiation system in detail. The detonator is composed of LX-16, for which we use a program burn model. Steinberg-Guinan models5 are used for the metal components of the detonator. The booster and high explosive are LX-10 and LX-17, respectively. For both the LX-10 and LX-17, we use a pressure dependent rate law, coupled with a chemical equilibrium equation of state based on Cheetah. For LX-17, the kinetic model includes carbon clustering on the nanometer size scale.

  6. 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

  7. 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.

  8. Background modeling for the GERDA experiment

    Science.gov (United States)

    Becerici-Schmidt, N.; Gerda Collaboration

    2013-08-01

    The neutrinoless double beta (0νββ) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0νββ decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Qββ come from 214Bi, 228Th, 42K, 60Co and α emitting isotopes in the 226Ra decay chain, with a fraction depending on the assumed source positions.

  9. Background modeling for the GERDA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Becerici-Schmidt, N. [Max-Planck-Institut für Physik, München (Germany); Collaboration: GERDA Collaboration

    2013-08-08

    The neutrinoless double beta (0νββ) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0νββ decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Q{sub ββ} come from {sup 214}Bi, {sup 228}Th, {sup 42}K, {sup 60}Co and α emitting isotopes in the {sup 226}Ra decay chain, with a fraction depending on the assumed source positions.

  10. Modelization of ratcheting in biaxial experiments

    International Nuclear Information System (INIS)

    Guionnet, C.

    1989-08-01

    A new unified viscoplastic constitutive equation has been developed in order to interpret ratcheting experiments on mechanical structures of fast reactors. The model is based essentially on a generalized Armstrong Frederick equation for the kinematic variable; the coefficients of the dynamic recovery term in this equation is a function of both instantaneous and accumulated inelastic strain which is allowed to vary in an appropriate manner in order to reproduce the experimental ratcheting rate. The validity of the model is verified by comparing predictions with experimental results for austenitic stainless steel (17-12 SPH) tubular specimens subjected to cyclic torsional loading under constant tensile stress at 600 0 C [fr

  11. 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.

  12. The Geodynamo: Models and supporting experiments

    International Nuclear Information System (INIS)

    Mueller, U.; Stieglitz, R.

    2003-03-01

    The magnetic field is a characteristic feature of our planet Earth. It shelters the biosphere against particle radiation from the space and offers by its direction orientation to creatures. The question about its origin has challenged scientists to find sound explanations. Major progress has been achieved during the last two decades in developing dynamo models and performing corroborating laboratory experiments to explain convincingly the principle of the Earth magnetic field. The article reports some significant steps towards our present understanding of this subject and outlines in particular relevant experiments, which either substantiate crucial elements of self-excitation of magnetic fields or demonstrate dynamo action completely. The authors are aware that they have not addressed all aspects of geomagnetic studies; rather, they have selected the material from the huge amount of literature such as to motivate the recently growing interest in experimental dynamo research. (orig.)

  13. 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

  14. Argonne Bubble Experiment Thermal Model Development II

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

    This report describes the continuation of the work reported in “Argonne Bubble Experiment Thermal Model Development”. 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 three beam power levels, 6, 12 and 15 kW. Solution temperatures were measured by thermocouples, and gas bubble behavior was observed. 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 irradiations. The previous report described an initial analysis performed on a geometry that had not been updated to reflect the as-built solution vessel. Here, the as-built geometry is used. Monte-Carlo N-Particle (MCNP) calculations were performed on the updated geometry, and these results were used to define the power deposition profile for the CFD analyses, which were performed using Fluent, Ver. 16.2. CFD analyses were performed for the 12 and 15 kW irradiations, and further improvements to the model were incorporated, including the consideration of power deposition in nearby vessel components, gas mixture composition, and bubble size distribution. The temperature results of the CFD calculations are compared to experimental measurements.

  15. Analysing population numbers of the house sparrow in the Netherlands with a matrix model and suggestions for conservation measures

    NARCIS (Netherlands)

    Klok, C.; Holtkamp, R.; Apeldoorn, van R.C.; Visser, M.E.; Hemerik, L.

    2006-01-01

    The House Sparrow (Passer domesticus), formerly a common bird species, has shown a rapid decline in Western Europe over recent decades. In The Netherlands, its decline is apparent from 1990 onwards. Many causes for this decline have been suggested that all decrease the vital rates, i.e. survival and

  16. Exposure–response model for sibutramine and placebo: suggestion for application to long-term weight-control drug development

    Science.gov (United States)

    Han, Seunghoon; Jeon, Sangil; Hong, Taegon; Lee, Jongtae; Bae, Soo Hyeon; Park, Wan-su; Park, Gab-jin; Youn, Sunil; Jang, Doo Yeon; Kim, Kyung-Soo; Yim, Dong-Seok

    2015-01-01

    No wholly successful weight-control drugs have been developed to date, despite the tremendous demand. We present an exposure–response model of sibutramine mesylate that can be applied during clinical development of other weight-control drugs. Additionally, we provide a model-based evaluation of sibutramine efficacy. Data from a double-blind, randomized, placebo-controlled, multicenter study were used (N=120). Subjects in the treatment arm were initially given 8.37 mg sibutramine base daily, and those who lost sibutramine, including the placebo effect, were modeled using NONMEM 7.2. An asymptotic model approaching the final body weight was chosen to describe the time course of weight loss. Extent of weight loss was described successfully using a sigmoidal exposure–response relationship of the drug with a constant placebo effect in each individual. The placebo effect was influenced by subjects’ sex and baseline body mass index. Maximal weight loss was predicted to occur around 1 year after treatment initiation. The difference in mean weight loss between the sibutramine (daily 12.55 mg) and placebo groups was predicted to be 4.5% in a simulation of 1 year of treatment, with considerable overlap of prediction intervals. Our exposure–response model, which included the placebo effect, is the first example of a quantitative model that can be used to predict the efficacy of weight-control drugs. Similar approaches can help decision-making during clinical development of novel weight-loss drugs. PMID:26392753

  17. Exposure-response model for sibutramine and placebo: suggestion for application to long-term weight-control drug development.

    Science.gov (United States)

    Han, Seunghoon; Jeon, Sangil; Hong, Taegon; Lee, Jongtae; Bae, Soo Hyeon; Park, Wan-su; Park, Gab-jin; Youn, Sunil; Jang, Doo Yeon; Kim, Kyung-Soo; Yim, Dong-Seok

    2015-01-01

    No wholly successful weight-control drugs have been developed to date, despite the tremendous demand. We present an exposure-response model of sibutramine mesylate that can be applied during clinical development of other weight-control drugs. Additionally, we provide a model-based evaluation of sibutramine efficacy. Data from a double-blind, randomized, placebo-controlled, multicenter study were used (N=120). Subjects in the treatment arm were initially given 8.37 mg sibutramine base daily, and those who lost sibutramine, including the placebo effect, were modeled using NONMEM 7.2. An asymptotic model approaching the final body weight was chosen to describe the time course of weight loss. Extent of weight loss was described successfully using a sigmoidal exposure-response relationship of the drug with a constant placebo effect in each individual. The placebo effect was influenced by subjects' sex and baseline body mass index. Maximal weight loss was predicted to occur around 1 year after treatment initiation. The difference in mean weight loss between the sibutramine (daily 12.55 mg) and placebo groups was predicted to be 4.5% in a simulation of 1 year of treatment, with considerable overlap of prediction intervals. Our exposure-response model, which included the placebo effect, is the first example of a quantitative model that can be used to predict the efficacy of weight-control drugs. Similar approaches can help decision-making during clinical development of novel weight-loss drugs.

  18. A proposed experiment on ball lightning model

    International Nuclear Information System (INIS)

    Ignatovich, Vladimir K.; Ignatovich, Filipp V.

    2011-01-01

    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.

  19. Multiaxial behavior of foams - Experiments and modeling

    Science.gov (United States)

    Maheo, Laurent; Guérard, Sandra; Rio, Gérard; Donnard, Adrien; Viot, Philippe

    2015-09-01

    Cellular materials are strongly related to pressure level inside the material. It is therefore important to use experiments which can highlight (i) the pressure-volume behavior, (ii) the shear-shape behavior for different pressure level. Authors propose to use hydrostatic compressive, shear and combined pressure-shear tests to determine cellular materials behavior. Finite Element Modeling must take into account these behavior specificities. Authors chose to use a behavior law with a Hyperelastic, a Viscous and a Hysteretic contributions. Specific developments has been performed on the Hyperelastic one by separating the spherical and the deviatoric part to take into account volume change and shape change characteristics of cellular materials.

  20. 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)

  1. 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)

  2. 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)

  3. 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.

  4. 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...... or activated macrophages, increasing the phagocytic ability of resting and activated macrophages simultaneously and lastly, adding additional macrophages to the site of inflammation. The latter seems counter-intuitive at first glance, but nevertheless it appears to be the most promising, as evidenced by recent...

  5. 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.

  6. 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.

  7. 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.

  8. Challenges and uncertainties in hydrological modelling of remote Hindu Kush-Himalayan (HKH) basins: suggestions for calibration strategies

    NARCIS (Netherlands)

    Pellicciotti, F.; Konz, M.; Immerzeel, W.W.; Shresta, A.B.

    2012-01-01

    Assessment of water resources from remote mountainous catchments plays a crucial role for the development of rural areas in or in the vicinity of mountain ranges. The scarcity of data, however, prevents the application of standard approaches that are based on data-driven models. The Hindu

  9. 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.

  10. Exposure–response model for sibutramine and placebo: suggestion for application to long-term weight-control drug development

    Directory of Open Access Journals (Sweden)

    Han S

    2015-09-01

    Full Text Available Seunghoon Han,1,2 Sangil Jeon,1,2 Taegon Hong,1,2 Jongtae Lee,1,2 Soo Hyeon Bae,1,2 Wan-su Park,1,2 Gab-jin Park,1,2 Sunil Youn,1,2 Doo Yeon Jang,1,2 Kyung-Soo Kim,3 Dong-Seok Yim1,2 1Department of Pharmacology, College of Medicine, The Catholic University of Korea, 2Pharmacometrics Institute for Practical Education and Training, 3Department of Family Medicine, Seoul St Mary’s Hospital, Seochogu, Seoul, Republic of KoreaAbstract: No wholly successful weight-control drugs have been developed to date, despite the tremendous demand. We present an exposure–response model of sibutramine mesylate that can be applied during clinical development of other weight-control drugs. Additionally, we provide a model-based evaluation of sibutramine efficacy. Data from a double-blind, randomized, placebo-controlled, multicenter study were used (N=120. Subjects in the treatment arm were initially given 8.37 mg sibutramine base daily, and those who lost <2 kg after 4 weeks’ treatment were escalated to 12.55 mg. The duration of treatment was 24 weeks. Drug concentration and body weight were measured predose and at 4 weeks, 8 weeks, and 24 weeks after treatment initiation. Exposure and response to sibutramine, including the placebo effect, were modeled using NONMEM 7.2. An asymptotic model approaching the final body weight was chosen to describe the time course of weight loss. Extent of weight loss was described successfully using a sigmoidal exposure–response relationship of the drug with a constant placebo effect in each individual. The placebo effect was influenced by subjects’ sex and baseline body mass index. Maximal weight loss was predicted to occur around 1 year after treatment initiation. The difference in mean weight loss between the sibutramine (daily 12.55 mg and placebo groups was predicted to be 4.5% in a simulation of 1 year of treatment, with considerable overlap of prediction intervals. Our exposure–response model, which

  11. A novel adoptive transfer model of chronic lymphocytic leukemia suggests a key role for T lymphocytes in the disease

    OpenAIRE

    Bagnara, Davide; Kaufman, Matthew S.; Calissano, Carlo; Marsilio, Sonia; Patten, Piers E. M.; Simone, Rita; Chum, Philip; Yan, Xiao-Jie; Allen, Steven L.; Kolitz, Jonathan E.; Baskar, Sivasubramanian; Rader, Christoph; Mellstedt, Hakan; Rabbani, Hodjattallah; Lee, Annette

    2011-01-01

    Chronic lymphocytic leukemia (CLL) is an incurable adult disease of unknown etiology. Understanding the biology of CLL cells, particularly cell maturation and growth in vivo, has been impeded by lack of a reproducible adoptive transfer model. We report a simple, reproducible system in which primary CLL cells proliferate in nonobese diabetes/severe combined immunodeficiency/γcnull mice under the influence of activated CLL-derived T lymphocytes. By cotransferring autologous T lymphocytes, activ...

  12. 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.

  13. VDR regulation of microRNA differs across prostate cell models suggesting extremely flexible control of transcription.

    Science.gov (United States)

    Singh, Prashant K; Long, Mark D; Battaglia, Sebastiano; Hu, Qiang; Liu, Song; Sucheston-Campbell, Lara E; Campbell, Moray J

    2015-01-01

    The Vitamin D Receptor (VDR) is a member of the nuclear receptor superfamily and is of therapeutic interest in cancer and other settings. Regulation of microRNA (miRNA) by the VDR appears to be important to mediate its actions, for example, to control cell growth. To identify if and to what extent VDR-regulated miRNA patterns change in prostate cancer progression, we undertook miRNA microarray analyses in 7 cell models representing non-malignant and malignant prostate cells (RWPE-1, RWPE-2, HPr1, HPr1AR, LNCaP, LNCaP-C4-2, and PC-3). To focus on primary VDR regulatory events, we undertook expression analyses after 30 minutes treatment with 1α,25(OH)2D3. Across all models, 111 miRNAs were significantly modulated by 1α,25(OH)2D3 treatment. Of these, only 5 miRNAs were modulated in more than one cell model, and of these, only 3 miRNAs were modulated in the same direction. The patterns of miRNA regulation, and the networks they targeted, significantly distinguished the different cell types. Integration of 1α,25(OH)2D3-regulated miRNAs with published VDR ChIP-seq data showed significant enrichment of VDR peaks in flanking regions of miRNAs. Furthermore, mRNA and miRNA expression analyses in non-malignant RWPE-1 cells revealed patterns of miRNA and mRNA co-regulation; specifically, 13 significant reciprocal patterns were identified and these patterns were also observed in TCGA prostate cancer data. Lastly, motif search analysis revealed differential motif enrichment within VDR peaks flanking mRNA compared to miRNA genes. Together, this study revealed that miRNAs are rapidly regulated in a highly cell-type specific manner, and are significantly co-integrated with mRNA regulation.

  14. Micro Wire-Drawing: Experiments And Modelling

    International Nuclear Information System (INIS)

    Berti, G. A.; Monti, M.; Bietresato, M.; D'Angelo, L.

    2007-01-01

    In the paper, the authors propose to adopt the micro wire-drawing as a key for investigating models of micro forming processes. The reasons of this choice arose in the fact that this process can be considered a quasi-stationary process where tribological conditions at the interface between the material and the die can be assumed to be constant during the whole deformation. Two different materials have been investigated: i) a low-carbon steel and, ii) a nonferrous metal (copper). The micro hardness and tensile tests performed on each drawn wire show a thin hardened layer (more evident then in macro wires) on the external surface of the wire and hardening decreases rapidly from the surface layer to the center. For the copper wire this effect is reduced and traditional material constitutive model seems to be adequate to predict experimentation. For the low-carbon steel a modified constitutive material model has been proposed and implemented in a FE code giving a better agreement with the experiments

  15. 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

  16. Pipe missile impact experiments on concrete models

    International Nuclear Information System (INIS)

    McHugh, S.; Gupta, Y.; Seaman, L.

    1981-06-01

    The experiments described in this study are a part of SRI studies for EPRI on the local response of reinforced concrete panels to missile impacts. The objectives of this task were to determine the feasibility of using scale model tests to reproduce the impact response of reinforced concrete panels observed in full-scale tests with pipe missiles and to evaluate the effect of concrete strength on the impact response. The experimental approach consisted of replica scaling: the missile and target materials were similar to those used in the full-scale tests, with all dimensions scaled by 5/32. Four criteria were selected for comparing the scaled and full-scale test results: frontface penetration, backface scabbing threshold, internal cracking in the panel, and missile deformation

  17. Hypergraph-Based Recognition Memory Model for Lifelong Experience

    Science.gov (United States)

    2014-01-01

    Cognitive agents are expected to interact with and adapt to a nonstationary dynamic environment. As an initial process of decision making in a real-world agent interaction, familiarity judgment leads the following processes for intelligence. Familiarity judgment includes knowing previously encoded data as well as completing original patterns from partial information, which are fundamental functions of recognition memory. Although previous computational memory models have attempted to reflect human behavioral properties on the recognition memory, they have been focused on static conditions without considering temporal changes in terms of lifelong learning. To provide temporal adaptability to an agent, in this paper, we suggest a computational model for recognition memory that enables lifelong learning. The proposed model is based on a hypergraph structure, and thus it allows a high-order relationship between contextual nodes and enables incremental learning. Through a simulated experiment, we investigate the optimal conditions of the memory model and validate the consistency of memory performance for lifelong learning. PMID:25371665

  18. Josephson cross-sectional model experiment

    International Nuclear Information System (INIS)

    Ketchen, M.B.; Herrell, D.J.; Anderson, C.J.

    1985-01-01

    This paper describes the electrical design and evaluation of the Josephson cross-sectional model (CSM) experiment. The experiment served as a test vehicle to verify the operation at liquid-helium temperatures of Josephson circuits integrated in a package environment suitable for high-performance digital applications. The CSM consisted of four circuit chips assembled on two cards in a three-dimensional card-on-board package. The chips (package) were fabricated in a 2.5-μm (5-μm) minimum linewidth Pb-alloy technology. A hierarchy of solder and pluggable connectors was used to attach the parts together and to provide electrical interconnections between parts. A data path which simulated a jump control sequence and a cache access in each machine cycle was successfully operated with cycle times down to 3.7 ns. The CSM incorporated the key components of the logic, power, and package of a prototype Josephson signal processor and demonstrated the feasibility of making such a processor with a sub-4-ns cycle time

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. The OECI model: the CRO Aviano experience.

    Science.gov (United States)

    Da Pieve, Lucia; Collazzo, Raffaele; Masutti, Monica; De Paoli, Paolo

    2015-01-01

    In 2012, the "Centro di Riferimento Oncologico" (CRO) National Cancer Institute joined the accreditation program of the Organisation of European Cancer Institutes (OECI) and was one of the first institutes in Italy to receive recognition as a Comprehensive Cancer Center. At the end of the project, a strengths, weaknesses, opportunities, and threats (SWOT) analysis aimed at identifying the pros and cons, both for the institute and of the accreditation model in general, was performed. The analysis shows significant strengths, such as the affinity with other improvement systems and current regulations, and the focus on a multidisciplinary approach. The proposed suggestions for improvement concern mainly the structure of the standards and aim to facilitate the assessment, benchmarking, and sharing of best practices. The OECI accreditation model provided a valuable executive tool and a framework in which we can identify several important development projects. An additional impact for our institute is the participation in the project BenchCan, of which the OECI is lead partner.

  4. 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

  5. Modeling of high power ICRF heating experiments on TFTR

    International Nuclear Information System (INIS)

    Phillips, C.K.; Wilson, J.R.; Bell, M.; Fredrickson, E.; Hosea, J.C.; Majeski, R.; Ramsey, A.; Rogers, J.H.; Schilling, G.; Skinner, C.; Stevens, J.E.; Taylor, G.; Wong, K.L.; Murakami, M.

    1993-01-01

    Over the past two years, ICRF heating experiments have been performed on TFTR in the hydrogen minority heating regime with power levels reaching 11.2 MW in helium-4 majority plasmas and 8.4 MW in deuterium majority plasmas. For these power levels, the minority hydrogen ions, which comprise typically less than 10% of the total electron density, evolve into la very energetic, anisotropic non-Maxwellian distribution. Indeed, the excess perpendicular stored energy in these plasmas associated with the energetic minority tail ions is often as high as 25% of the total stored energy, as inferred from magnetic measurements. Enhanced losses of 0.5 MeV protons consistent with the presence of an energetic hydrogen component have also been observed. In ICRF heating experiments on JET at comparable and higher power levels and with similar parameters, it has been suggested that finite banana width effects have a noticeable effect on the ICRF power deposition. In particular, models indicate that finite orbit width effects lead to a reduction in the total stored energy and of the tail energy in the center of the plasma, relative to that predicted by the zero banana width models. In this paper, detailed comparisons between the calculated ICRF power deposition profiles and experimentally measured quantities will be presented which indicate that significant deviations from the zero banana width models occur even for modest power levels (P rf ∼ 6 MW) in the TFTR experiments

  6. 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.

  7. 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.

  8. Danish heathland manipulation experiment data in Model-Data-Fusion

    Science.gov (United States)

    Thum, Tea; Peylin, Philippe; Ibrom, Andreas; Van Der Linden, Leon; Beier, Claus; Bacour, Cédric; Santaren, Diego; Ciais, Philippe

    2013-04-01

    In ecosystem manipulation experiments (EMEs) the ecosystem is artificially exposed to different environmental conditions that aim to simulate circumstances in future climate. At Danish EME site Brandbjerg the responses of a heathland to drought, warming and increased atmospheric CO2 concentration are studied. The warming manipulation is realized by passive nighttime warming. The measurements include control plots as well as replicates for each three treatment separately and in combination. The Brandbjerg heathland ecosystem is dominated by heather and wavy hairgrass. These experiments provide excellent data for validation and development of ecosystem models. In this work we used a generic vegetation model ORCHIDEE with Model-Data-Fusion (MDF) approach. ORCHIDEE model is a process-based model that describes the exchanges of carbon, water and energy between the atmosphere and the vegetation. It can be run at different spatial scales from global to site level. Different vegetation types are described in ORCHIDEE as plant functional types. In MDF we are using observations from the site to optimize the model parameters. This enables us to assess the modelling errors and the performance of the model for different manipulation treatments. This insight will inform us whether the different processes are adequately modelled or if the model is missing some important processes. We used a genetic algorithm in the MDF. The data available from the site included measurements of aboveground biomass, heterotrophic soil respiration and total ecosystem respiration from years 2006-2008. The biomass was measured six times doing this period. The respiration measurements were done with manual chamber measurements. For the soil respiration we used results from an empirical model that has been developed for the site. This enabled us to have more data for the MDF. Before the MDF we performed a sensitivity analysis of the model parameters to different data streams. Fifteen most influential

  9. Suggestions for an adequate risk communication - experiences based on German epidemiological studies on childhood cancer and neighbourhood to nuclear power plants

    International Nuclear Information System (INIS)

    Kaatsch, P.

    2006-01-01

    From the example of the German studies on childhood cancer in the vicinity of nuclear power plants general principles for adequate risk communication could be derived. It is particularly important to explain the complexity of the issue to the public in an adequate way, when dealing with topics of such an emotionally loaded nature. Some rules are required, when explaining the nature of risk to the layman, the press, politicians, or scientists from other fields. The main principle is to create a basis of trustfulness, whereupon results can be presented. In this contribution we derive general and proven specific recommendations for adequate risk communication on the basis of experiences made at the German Childhood Cancer Registry. (orig.)

  10. 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

  11. Replication and extension of the dual pathway model of disordered eating: The role of fear of negative evaluation, suggestibility, rumination, and self-compassion.

    Science.gov (United States)

    Maraldo, Toni M; Zhou, Wanni; Dowling, Jessica; Vander Wal, Jillon S

    2016-12-01

    The dual pathway model, a theoretical model of eating disorder development, suggests that thin ideal internalization leads to body dissatisfaction which leads to disordered eating via the dual pathways of negative affect and dietary restraint. While the dual pathway model has been a valuable guide for eating disorder prevention, greater knowledge of characteristics that predict thin ideal internalization is needed. The present study replicated and extended the dual pathway model by considering the addition of fear of negative evaluation, suggestibility, rumination, and self-compassion in a sample of community women and female university students. Results showed that fear of negative evaluation and suggestibility predicted thin ideal internalization whereas rumination and self-compassion (inversely) predicted body dissatisfaction. Negative affect was predicted by fear of negative evaluation, rumination, and self-compassion (inversely). The extended model fit the data well in both samples. Analogue and longitudinal study of these constructs is warranted in future research. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Experiments and modeling of single plastic particle conversion in suspension

    DEFF Research Database (Denmark)

    Nakhaei, Mohammadhadi; Wu, Hao; Grévain, Damien

    2018-01-01

    Conversion of single high density polyethylene (PE) particles has been studied by experiments and modeling. The experiments were carried out in a single particle combustor for five different shapes and masses of particles at temperature conditions of 900 and 1100°C. Each experiment was recorded...... against the experiments as well as literature data. Furthermore, a simplified isothermal model appropriate for CFD applications was developed, in order to model the combustion of plastic particles in cement calciners. By comparing predictions with the isothermal and the non–isothermal models under typical...

  13. Effects of anti-inflammatory compounds on sulfur mustard injured cells: Recommendations and caveats suggested by in vitro cell culture models.

    Science.gov (United States)

    Menacher, Georg; Steinritz, Dirk; Schmidt, Annette; Popp, Tanja; Worek, Franz; Gudermann, Thomas; Thiermann, Horst; Balszuweit, Frank

    2018-09-01

    harmful. Diclofenac significantly reduced necrosis, apoptosis and inflammation in the co-culture in a dose-dependent manner. The greatest benefit regarding cell survival and reduction of the inflammation-marker IL-6 after a SM treatment was observed after diclofenac treatment. The protective effects of diclofenac were less pronounced in the monoculture which suggests, that diclofenac can modify the response of immune cells to SM. In conclusion, the results of our experiments, showing a benefit for diclofenac after SM exposure are in line with in vivo data of other researchers. Though, our in vitro results suggest the preferred use of diclofenac over ibuprofen. The benefit of dexamethasone is still equivocal, but low concentrations seem to have some positive effects. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Experiments and Modelling of Coal Devolatilization

    Institute of Scientific and Technical Information of China (English)

    QiuKuanrong; LiuQianxin

    1994-01-01

    The coal devolatilization process of different coals was studied by means of thermogravimetric analysis method.The experimental results and the kinetic parameters of devolatilization.K and E,have been obtained. A mathematical model for coal devolatiliztion has been proposed.and the model is simple and practical.The predictions of the model are shown to be in agreement with experimental results.

  15. 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...

  16. Quality of experience models for multimedia streaming

    NARCIS (Netherlands)

    Menkovski, V.; Exarchakos, G.; Liotta, A.; Cuadra Sánchez, A.

    2010-01-01

    Understanding how quality is perceived by viewers of multimedia streaming services is essential for efficient management of those services. Quality of Experience (QoE) is a subjective metric that quantifies the perceived quality, which is crucial in the process of optimizing tradeoff between quality

  17. A Cross-Discipline Modeling Capstone Experience

    Science.gov (United States)

    Frazier, Marian L.; LoFaro, Thomas; Pillers Dobler, Carolyn

    2018-01-01

    The Mathematical Association of America (MAA) and the American Statistical Association (ASA) have both updated and revised their curriculum guidelines. The guidelines of both associations recommend that students engage in a "capstone" experience, be exposed to applications, and have opportunities to communicate mathematical and…

  18. 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…

  19. 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-dependent and their applicab...

  20. 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…

  1. Hybrid rocket engine, theoretical model and experiment

    Science.gov (United States)

    Chelaru, Teodor-Viorel; Mingireanu, Florin

    2011-06-01

    The purpose of this paper is to build a theoretical model for the hybrid rocket engine/motor and to validate it using experimental results. The work approaches the main problems of the hybrid motor: the scalability, the stability/controllability of the operating parameters and the increasing of the solid fuel regression rate. At first, we focus on theoretical models for hybrid rocket motor and compare the results with already available experimental data from various research groups. A primary computation model is presented together with results from a numerical algorithm based on a computational model. We present theoretical predictions for several commercial hybrid rocket motors, having different scales and compare them with experimental measurements of those hybrid rocket motors. Next the paper focuses on tribrid rocket motor concept, which by supplementary liquid fuel injection can improve the thrust controllability. A complementary computation model is also presented to estimate regression rate increase of solid fuel doped with oxidizer. Finally, the stability of the hybrid rocket motor is investigated using Liapunov theory. Stability coefficients obtained are dependent on burning parameters while the stability and command matrixes are identified. The paper presents thoroughly the input data of the model, which ensures the reproducibility of the numerical results by independent researchers.

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

    DEFF Research Database (Denmark)

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

    2003-01-01

    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...

  3. Suicidality and interrogative suggestibility.

    Science.gov (United States)

    Pritchard-Boone, Lea; Range, Lillian M

    2005-01-01

    All people are subject to memory suggestibility, but suicidal individuals may be especially so. The link between suicidality and suggestibility is unclear given mixed findings and methodological weaknesses of past research. To test the link between suicidality and interrogative suggestibility, 149 undergraduates answered questions about suicidal thoughts and reasons for living, and participated in a direct suggestibility procedure. As expected, suggestibility correlated with suicidality but accounted for little overall variance (4%). Mental health professionals might be able to take advantage of client suggestibility by directly telling suicidal persons to refrain from suicidal thoughts or actions.

  4. Indian Ocean experiments with a coupled model

    Energy Technology Data Exchange (ETDEWEB)

    Wainer, I. [Sao Paulo, Univ. (Brazil). Dept. of Oceanography

    1997-03-01

    A coupled ocean-atmosphere model is used to investigate the equatorial Indian Ocean response to the seasonally varying monsoon winds. Special attention is given to the oceanic response to the spatial distribution and changes in direction of the zonal winds. The Indian Ocean is surrounded by an Asian land mass to the North and an African land mass to the West. The model extends latitudinally between 41 N and 41 S. The asymmetric atmospheric model is driven by a mass source/sink term that is proportional to the sea surface temperature (SST) over the oceans and the heat balance over the land. The ocean is modeled using the Anderson and McCreary reduced-gravity transport model that includes a prognostic equation for the SST. The coupled system is driven by the annual cycle as manifested by zonally symmetric and asymmetric land and ocean heating. They explored the different nature of the equatorial ocean response to various patterns of zonal wind stress forcing in order to isolate the impact of the remote response on the Somali current. The major conclusions are : i) the equatorial response is fundamentally different for easterlies and westerlies, ii) the impact of the remote forcing on the Somali current is a function of the annual cycle, iii) the size of the basin sets the phase of the interference of the remote forcing on the Somali current relative to the local forcing.

  5. Twentieth century Walker Circulation change: data analysis and model experiments

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Qingjia [Leibniz-Institut fuer Meereswissenschaften, Kiel (Germany); Chinese Research Academy of Environmental Sciences, River and Coastal Environment Research Center, Beijing (China); Chinese Academy of Sciences, Key Laboratory of Ocean Circulation and Waves, Institute of Oceanology, Qingdao (China); Latif, Mojib; Park, Wonsun; Keenlyside, Noel S.; Martin, Thomas [Leibniz-Institut fuer Meereswissenschaften, Kiel (Germany); Semenov, Vladimir A. [Leibniz-Institut fuer Meereswissenschaften, Kiel (Germany); A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow (Russian Federation)

    2012-05-15

    Recent studies indicate a weakening of the Walker Circulation during the twentieth century. Here, we present evidence from an atmospheric general circulation model (AGCM) forced by the history of observed sea surface temperature (SST) that the Walker Circulation may have intensified rather than weakened. Observed Equatorial Indo-Pacific Sector SST since 1870 exhibited a zonally asymmetric evolution: While the eastern part of the Equatorial Pacific showed only a weak warming, or even cooling in one SST dataset, the western part and the Equatorial Indian Ocean exhibited a rather strong warming. This has resulted in an increase of the SST gradient between the Maritime Continent and the eastern part of the Equatorial Pacific, one driving force of the Walker Circulation. The ensemble experiments with the AGCM, with and without time-varying external forcing, suggest that the enhancement of the SST gradient drove an anomalous atmospheric circulation, with an enhancement of both Walker and Hadley Circulation. Anomalously strong precipitation is simulated over the Indian Ocean and anomalously weak precipitation over the western Pacific, with corresponding changes in the surface wind pattern. Some sensitivity to the forcing SST, however, is noticed. The analysis of twentieth century integrations with global climate models driven with observed radiative forcing obtained from the Coupled Model Intercomparison Project (CMIP) database support the link between the SST gradient and Walker Circulation strength. Furthermore, control integrations with the CMIP models indicate the existence of strong internal variability on centennial timescales. The results suggest that a radiatively forced signal in the Walker Circulation during the twentieth century may have been too weak to be detectable. (orig.)

  6. Model Experiments for the Determination of Airflow in Large Spaces

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    Model experiments are one of the methods used for the determination of airflow in large spaces. This paper will discuss the formation of the governing dimensionless numbers. It is shown that experiments with a reduced scale often will necessitate a fully developed turbulence level of the flow....... Details of the flow from supply openings are very important for the determination of room air distribution. It is in some cases possible to make a simplified supply opening for the model experiment....

  7. 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.

  8. Deformation of wrought uranium: Experiments and modeling

    Energy Technology Data Exchange (ETDEWEB)

    McCabe, R.J., E-mail: rmccabe@lanl.gov [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Capolungo, L. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)] [UMI 2958 Georgia Tech - CNRS, 57070 Metz (France); Marshall, P.E.; Cady, C.M.; Tome, C.N. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2010-09-15

    The room temperature deformation behavior of wrought polycrystalline uranium is studied using a combination of experimental techniques and polycrystal modeling. Electron backscatter diffraction is used to analyze the primary deformation twinning modes for wrought alpha-uranium. The {l_brace}1 3 0{r_brace}<3 1 0> twinning mode is found to be the most prominent twinning mode, with minor contributions from the '{l_brace}1 7 2{r_brace}'<3 1 2> and {l_brace}1 1 2{r_brace}'<3 7 2>' twin modes. Because of the large number of deformation modes, each with limited deformation systems, a polycrystalline model is employed to identify and quantify the activity of each mode. Model predictions of the deformation behavior and texture development agree reasonably well with experimental measures and provide reliable information about deformation systems.

  9. 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

  10. 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.

  11. 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

  12. 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...

  13. Previous Experience a Model of Practice UNAE

    OpenAIRE

    Ormary Barberi Ruiz; María Dolores Pesántez Palacios

    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...

  14. Pyroelectric Energy Harvesting: Model and Experiments

    Science.gov (United States)

    2016-05-01

    consisting of a current source for the pyroelectric current, a dielectric capacitor for the adiabatic charging and discharging, and optionally a resistor to...polarization) in a piezoelectric material. To extract work from the pyroelectric effect, the material acts as the dielectric in a capacitor that is...amplifier was chosen for the setup. The pyroelectric element is commonly modeled as a dielectric capacitor and a current source in parallel, as seen in

  15. Previous Experience a Model of Practice UNAE

    Directory of Open Access Journals (Sweden)

    Ormary Barberi Ruiz

    2017-02-01

    Full Text Available 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 subject nature of the pre professional practice and the demand of socio educational contexts where the practices have been emerging to resize them. By relating these elements allowed conceiving the modeling of the processes of the pre-professional practices for the development of professional skills of future teachers through four components: contextual projective, implementation (tutoring, accompaniment (teaching couple and monitoring (meetings at the beginning, during and end of practice. The initial training of teachers is inherent to teaching (academic and professional training, research and links with the community, these are fundamental pillars of Ecuadorian higher education.

  16. 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...

  17. 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.

  18. Representational constraints on children's suggestibility.

    Science.gov (United States)

    Ceci, Stephen J; Papierno, Paul B; Kulkofsky, Sarah

    2007-06-01

    In a multistage experiment, twelve 4- and 9-year-old children participated in a triad rating task. Their ratings were mapped with multidimensional scaling, from which euclidean distances were computed to operationalize semantic distance between items in target pairs. These children and age-mates then participated in an experiment that employed these target pairs in a story, which was followed by a misinformation manipulation. Analyses linked individual and developmental differences in suggestibility to children's representations of the target items. Semantic proximity was a strong predictor of differences in suggestibility: The closer a suggested distractor was to the original item's representation, the greater was the distractor's suggestive influence. The triad participants' semantic proximity subsequently served as the basis for correctly predicting memory performance in the larger group. Semantic proximity enabled a priori counterintuitive predictions of reverse age-related trends to be confirmed whenever the distance between representations of items in a target pair was greater for younger than for older children.

  19. An experiment on a ball-lightning model

    International Nuclear Information System (INIS)

    Ignatovich, F.V.; Ignatovich, V.K.

    2010-01-01

    We discuss total internal reflection (TIR) from an interface between glass and gainy gaseous media and propose an experiment for strong light amplification related to investigation of a ball-lightning model

  20. 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.

  1. Modeling and experiment to threshing unit of stripper combine ...

    African Journals Online (AJOL)

    Modeling and experiment to threshing unit of stripper combine. ... were conducted with the different feed rates and drum rotator speeds for the rice stripped mixtures. ... and damage as well as for threshing unit design and process optimization.

  2. 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.

  3. 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

  4. 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

    One-dimensional and two-dimensional radial flow numerical models were used to evaluate the results for a 60.5 h ponded infiltration experiment done around a 24 m deep, 0.15 m diameter, cased borehole at Yucca Mountain, NV. Nine distinct morphological horizons in the soil profile has been identified; physical and hydraulic properties had been measured for each horizon; and a porosity profile at the borehole had been measured. During the infiltration experiment, 10 cm of water was ponded in a 3.5 m diameter infiltrometer around the borehole, the volume of water applied was measured, and water content profiles were measured with a neutron moisture meter. The infiltrometer applied 86.9 cm of water during the first 60.5 h of infiltration, but only 52.8 cm of additional water was measured in the borehole profiles. Assuming a linear relationship between cumulative infiltration (I) and the square root of time (t 0.5 ), an experimental sorptivity of 11.5 cm h -1 was estimated for the first 4.5 h of infiltration. An assumed washout zone around the borehole casing accounted for the discrepancy between the measured water content profiles and the applied water. A uniform property, 1-D model with an applied flux upper boundary described by the sorptivity confirmed the probable washout zone, and indicated that significant lateral flow into the dry soil around the infiltrometer could occur. A 2-D radial flow model with the same properties and upper boundary demonstrated that significant lateral flow occurred. The upper boundary in this model caused the upper portion of the profile to drain. This suggested using a saturated upper boundary to keep the upper portion of the profile saturated. When the saturated upper boundary was used, the permeability of the soil was decreased from the measured value of 3.28 E-11 m 2 to 1.5E-12 m 2 so that the simulated wetting front at a similar depth as the observed wetting front after 60.5 h

  5. Large scale FCI experiments in subassembly geometry. Test facility and model experiments

    International Nuclear Information System (INIS)

    Beutel, H.; Gast, K.

    A program is outlined for the study of fuel/coolant interaction under SNR conditions. The program consists of a) under water explosion experiments with full size models of the SNR-core, in which the fuel/coolant system is simulated by a pyrotechnic mixture. b) large scale fuel/coolant interaction experiments with up to 5kg of molten UO 2 interacting with liquid sodium at 300 deg C to 600 deg C in a highly instrumented test facility simulating an SNR subassembly. The experimental results will be compared to theoretical models under development at Karlsruhe. Commencement of the experiments is expected for the beginning of 1975

  6. The α-fetoprotein knock-out mouse model suggests that parental behavior is sexually differentiated under the influence of prenatal estradiol

    Science.gov (United States)

    Keller, Matthieu; Pawluski, Jodi L.; Brock, Olivier; Douhard, Quentin; Bakker, Julie

    2010-01-01

    In rodent species, sexual differentiation of the brain for many reproductive processes depends largely on estradiol. This was recently confirmed again by using the α-fetoprotein knockout (AFP-KO) mouse model, which lacks the protective actions of α-fetoprotein against maternal estradiol and as a result represents a good model to determine the contribution of prenatal estradiol to the sexual differentiation of the brain and behavior. Female AFP-KO mice were defeminized and masculinized with regard to their neuroendocrine responses as well as sexual behavior. Since parental behavior is also strongly sexually differentiated in mice, we used the AFP-KO mouse model here to ask whether parental responses are differentiated prenatally under the influence of estradiol. It was found that AFP-KO females showed longer latencies to retrieve pups to the nest and also exhibited lower levels of crouching over the pups in the nest in comparison to WT females. In fact, they resembled males (WT and AFP-KO). Other measures of maternal behavior, for example the incidence of infanticide, tended to be higher in AFP-KO females than in WT females but this increase failed to reach statistical significance. The deficits observed in parental behavior of AFP-KO females could not be explained by any changes in olfactory function, novelty recognition or anxiety. Thus our results suggest that prenatal estradiol defeminizes the parental brain in mice. PMID:20109458

  7. 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...

  8. 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.

  9. Simulated Models Suggest That Price per Calorie Is the Dominant Price Metric That Low-Income Individuals Use for Food Decision Making123

    Science.gov (United States)

    2016-01-01

    Background: 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. Objective: We assessed which price metric is used by low-income individuals in deciding what to eat. Methods: 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. Results: 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. Conclusions: 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. PMID:27655757

  10. 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.

  11. TF insert experiment log book. 2nd Experiment of CS model coil

    International Nuclear Information System (INIS)

    Sugimoto, Makoto; Isono, Takaaki; Matsui, Kunihiro

    2001-12-01

    The cool down of CS model coil and TF insert was started on August 20, 2001. It took almost one month and immediately started coil charge since September 17, 2001. The charge test of TF insert and CS model coil was completed on October 19, 2001. In this campaign, total shot numbers were 88 and the size of the data file in the DAS (Data Acquisition System) was about 4 GB. This report is a database that consists of the log list and the log sheets of every shot. This is an experiment logbook for 2nd experiment of CS model coil and TF insert for charge test. (author)

  12. An Extremely Massive White Dwarf of the Symbiotic Classical Nova V407 Cyg as Suggested by the RS Oph and U SCO Models

    Directory of Open Access Journals (Sweden)

    Hachisu I.

    2012-06-01

    Full Text Available We have analyzed the optical light curve of the symbiotic star V407 Cyg that underwent a classical nova outburst in 2010 March. Being guided by a supersoft X-ray phase observed during days 20-40 after the nova outburst, we are able to reproduce the light curve during a very early phase of the nova outburst. Our model consists of an outbursting white dwarf and an extended equatorial disk. An extremely massive white dwarf of 1.35-1.37 M⊙ is suggested. the optical light curve is also consistent with a sharp drop 47 days after the outburst, which is the end of hydrogen shell-burning on the white dwarf. Although the extremely massive white dwarf is favourable to the interpretation that V407 Cyg is a recurrent nova, enrichment of heavy elements in the ejecta suggests that the white dwarf is eroded and, as a result, its mass is not increasing. Therefore, V407 Cyg may not explode as a Type Ia supernova even if it is a carbon-oxygen white dwarf.

  13. 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...

  14. Suggestive Objects at Work

    DEFF Research Database (Denmark)

    Ratner, Helene Gad

    2009-01-01

    In Western secular societies, spiritual life is no longer limited to classical religious institutions but can also be found at workplace organizations. While spirituality is conventionally understood as a subjective and internal process, this paper proposes the concept of ‘suggestive objects......’, constructed by combining insights from Gabriel Tarde's sociology with Bruno Latour's actor-network theory, to theorize the material dimension of organizational spirituality. The sacred in organizations arises not from the internalization of collective values but through the establishment of material...... scaffolding. This has deep implications for our understanding of the sacred, including a better appreciation of the way that suggestive objects make the sacred durable, the way they organize it....

  15. 3D mathematical modeling of glioblastoma suggests that transdifferentiated vascular endothelial cells mediate resistance to current standard-of-care therapy

    Science.gov (United States)

    Yan, Huaming; Romero-López, Mónica; Benitez, Lesly I.; Di, Kaijun; Frieboes, Hermann B.; Hughes, Christopher C. W.; Bota, Daniela A.; Lowengrub, John S.

    2017-01-01

    Glioblastoma (GBM), the most aggressive brain tumor in human patients, is decidedly heterogeneous and highly vascularized. Glioma stem/initiating cells (GSC) are found to play a crucial role by increasing cancer aggressiveness and promoting resistance to therapy. Recently, crosstalk between GSC and vascular endothelial cells has been shown to significantly promote GSC self-renewal and tumor progression. Further, GSC also transdifferentiate into bona-fide vascular endothelial cells (GEC), which inherit mutations present in GSC and are resistant to traditional anti-angiogenic therapies. Here we use 3D mathematical modeling to investigate GBM progression and response to therapy. The model predicted that GSC drive invasive fingering and that GEC spontaneously form a network within the hypoxic core, consistent with published experimental findings. Standard-of-care treatments using DNA-targeted therapy (radiation/chemo) together with anti-angiogenic therapies, reduced GBM tumor size but increased invasiveness. Anti-GEC treatments blocked the GEC support of GSC and reduced tumor size but led to increased invasiveness. Anti-GSC therapies that promote differentiation or disturb the stem cell niche effectively reduced tumor invasiveness and size, but were ultimately limited in reducing tumor size because GEC maintain GSC. Our study suggests that a combinatorial regimen targeting the vasculature, GSC, and GEC, using drugs already approved by the FDA, can reduce both tumor size and invasiveness and could lead to tumor eradication. PMID:28536277

  16. Model estimates of leaf area and reference canopy stomatal conductance suggest correlation between phenology and physiology in both trembling aspen and red pine

    Science.gov (United States)

    Mackay, D. S.; Ewers, B. E.; Kruger, E. L.

    2006-12-01

    Phenological variations impact water and carbon fluxes, as evidenced by the large interannual variability of net ecosystem exchange of carbon dioxide and evapotranspiration (ET). In northern Wisconsin we observed daily variations of canopy transpiration from hardwoods from 1.0 to 1.7 mm/day during the leaf unfolding period and 1.7 to 2.6 mm/day with leaves fully out. Correlations between such flux rates and phenology have not been extensively tested and mechanistic connections are in their infancy. Some data suggest that stomatal conductance and photosynthesis increases up to full expansion. Moreover, in conifers, the interaction of phenology and physiology is more complicated than in deciduous trees because needles are retained for several years. Using inverse modeling with a coupled photosynthesis-transpiration model we estimated reference canopy stomatal conductance, Gsref, for red pine (Pinus resinosa), and Gsref and leaf area index, L, for trembling aspen (Populus tremuloides), using 30-min continuous sap flux data spanning a period from just prior to the start of leaf expansion to just after leaf senescence. The red pine showed Gsref ramp up from 105 to 179 mmol m-2 leaf s-1, which represented a 37 to 50 percent increase in Gsref after accounting for maximum possible changes in L. After full leaf out, the trembling aspen were almost immediately defoliated, and then reflushed after three weeks. Model estimates of L reflected this pattern and were consistent with measurements. However, Gsref never exceeded 45 mmol m-2 s-1 prior to defoliation, but peaked at 112 mmol m-2 s-1 after reflushing. These results support the need for further work that aims to separate phenology and physiology.

  17. 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…

  18. Designing Experiments to Discriminate Families of Logic Models.

    Science.gov (United States)

    Videla, Santiago; Konokotina, Irina; Alexopoulos, Leonidas G; Saez-Rodriguez, Julio; Schaub, Torsten; Siegel, Anne; Guziolowski, Carito

    2015-01-01

    Logic models of signaling pathways are a promising way of building effective in silico functional models of a cell, in particular of signaling pathways. The automated learning of Boolean logic models describing signaling pathways can be achieved by training to phosphoproteomics data, which is particularly useful if it is measured upon different combinations of perturbations in a high-throughput fashion. However, in practice, the number and type of allowed perturbations are not exhaustive. Moreover, experimental data are unavoidably subjected to noise. As a result, the learning process results in a family of feasible logical networks rather than in a single model. This family is composed of logic models implementing different internal wirings for the system and therefore the predictions of experiments from this family may present a significant level of variability, and hence uncertainty. In this paper, we introduce a method based on Answer Set Programming to propose an optimal experimental design that aims to narrow down the variability (in terms of input-output behaviors) within families of logical models learned from experimental data. We study how the fitness with respect to the data can be improved after an optimal selection of signaling perturbations and how we learn optimal logic models with minimal number of experiments. The methods are applied on signaling pathways in human liver cells and phosphoproteomics experimental data. Using 25% of the experiments, we obtained logical models with fitness scores (mean square error) 15% close to the ones obtained using all experiments, illustrating the impact that our approach can have on the design of experiments for efficient model calibration.

  19. 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.

  20. 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.

  1. 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

  2. Topographic evolution of sandbars: Flume experiment and computational modeling

    Science.gov (United States)

    Kinzel, Paul J.; Nelson, Jonathan M.; McDonald, Richard R.; Logan, Brandy L.

    2010-01-01

    Measurements of sandbar formation and evolution were carried out in a laboratory flume and the topographic characteristics of these barforms were compared to predictions from a computational flow and sediment transport model with bed evolution. The flume experiment produced sandbars with approximate mode 2, whereas numerical simulations produced a bed morphology better approximated as alternate bars, mode 1. In addition, bar formation occurred more rapidly in the laboratory channel than for the model channel. This paper focuses on a steady-flow laboratory experiment without upstream sediment supply. Future experiments will examine the effects of unsteady flow and sediment supply and the use of numerical models to simulate the response of barform topography to these influences.

  3. 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

  4. 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.

  5. Grimsel Test Site: modelling radionuclide migration field experiments

    International Nuclear Information System (INIS)

    Heer, W.; Hadermann, J.

    1994-09-01

    In the migration field experiments at Nagra's Grimsel Test Site, the processes of nuclide transport through a well defined fractured shear-zone in crystalline rock are being investigated. For these experiments, model calculations have been performed to obtain indications on validity and limitation of the model applied and the data deduced under field conditions. The model consists of a hydrological part, where the dipole flow fields of the experiments are determined, and a nuclide transport part, where the flow field driven nuclide propagation through the shear-zone is calculated. In addition to the description of the model, analytical expressions are given to guide the interpretation of experimental results. From the analysis of experimental breakthrough curves for conservative uranine, weakly sorbing sodium and more stronger sorbing strontium tracers, the following main results can be derived: i) The model is able to represent the breakthrough curves of the migration field experiments to a high degree of accuracy, ii) The process of matrix diffusion is manifest through the tails of the breakthrough curves decreasing with time as t -3/2 and through the special shape of the tail ends, both confirmed by the experiments, iii) For nuclide sorbing rapidly, not too strongly, linearly, and exhibiting a reversible cation exchange process on fault gouge, the laboratory sorption coefficient can reasonably well be extrapolated to field conditions. Adequate care in selecting and preparing the rock samples is, of course, a necessary requirement. Using the parameters determined in the previous analysis, predictions are made for experiments in a smaller an faster flow field. For conservative uranine and weakly sorbing sodium, the agreement of predicted and measured breakthrough curves is good, for the more stronger sorbing strontium reasonable, confirming that the model describes the main nuclide transport processes adequately. (author) figs., tabs., 29 refs

  6. Modelling of laboratory high-pressure infiltration experiments

    International Nuclear Information System (INIS)

    Smith, P.A.

    1992-02-01

    This report describes the modelling of break-through curves from a series of two-tracer dynamic infiltration experiments, which are intended to complement larger scale experiments at the Nagra Grimsel Test Site. The tracers are 82 Br, which is expected to be non-sorbing, and 24 Na, which is weakly sorbing. The 24 Na concentration is well below the natural Na concentration in the infiltration fluid, so that sorption on the rock is governed by isotopic exchange, exhibiting a linear isotherm. The rock specimens are sub-samples (cores) of granodiorite from the Grimsel Test Site, each containing a distinct shear zone. Best-fits to the break-through curves using single-porosity and dual-porosity transport models are compared and several physical parameters are extracted. It is shown that the dual-porosity model is required in order to reproduce the tailing part of the break-through curves for the non-sorbing tracer. The single-porosity model is sufficient to reproduce the break-through curves for the sorbing tracer within the estimated experimental errors. Extracted K d values are shown to agree well with a field rock-water interaction experiment and in situ migration experiments. Static, laboratory batch-sorption experiments give a larger K d , but this difference could be explained by the larger surface area available for sorption in the artificially crushed samples used in the laboratory and by a slightly different water chemistry. (author) 13 figs., tabs., 19 refs

  7. Hohlraum modeling for opacity experiments on the National Ignition Facility

    Science.gov (United States)

    Dodd, E. S.; DeVolder, B. G.; Martin, M. E.; Krasheninnikova, N. S.; Tregillis, I. L.; Perry, T. S.; Heeter, R. F.; Opachich, Y. P.; Moore, A. S.; Kline, J. L.; Johns, H. M.; Liedahl, D. A.; Cardenas, T.; Olson, R. E.; Wilde, B. H.; Urbatsch, T. J.

    2018-06-01

    This paper discusses the modeling of experiments that measure iron opacity in local thermodynamic equilibrium (LTE) using laser-driven hohlraums at the National Ignition Facility (NIF). A previous set of experiments fielded at Sandia's Z facility [Bailey et al., Nature 517, 56 (2015)] have shown up to factors of two discrepancies between the theory and experiment, casting doubt on the validity of the opacity models. The purpose of the new experiments is to make corroborating measurements at the same densities and temperatures, with the initial measurements made at a temperature of 160 eV and an electron density of 0.7 × 1022 cm-3. The X-ray hot spots of a laser-driven hohlraum are not in LTE, and the iron must be shielded from a direct line-of-sight to obtain the data [Perry et al., Phys. Rev. B 54, 5617 (1996)]. This shielding is provided either with the internal structure (e.g., baffles) or external wall shapes that divide the hohlraum into a laser-heated portion and an LTE portion. In contrast, most inertial confinement fusion hohlraums are simple cylinders lacking complex gold walls, and the design codes are not typically applied to targets like those for the opacity experiments. We will discuss the initial basis for the modeling using LASNEX, and the subsequent modeling of five different hohlraum geometries that have been fielded on the NIF to date. This includes a comparison of calculated and measured radiation temperatures.

  8. 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.

  9. Integrated multiscale biomaterials experiment and modelling: a perspective

    Science.gov (United States)

    Buehler, Markus J.; Genin, Guy M.

    2016-01-01

    Advances in multiscale models and computational power have enabled a broad toolset to predict how molecules, cells, tissues and organs behave and develop. A key theme in biological systems is the emergence of macroscale behaviour from collective behaviours across a range of length and timescales, and a key element of these models is therefore hierarchical simulation. However, this predictive capacity has far outstripped our ability to validate predictions experimentally, particularly when multiple hierarchical levels are involved. The state of the art represents careful integration of multiscale experiment and modelling, and yields not only validation, but also insights into deformation and relaxation mechanisms across scales. We present here a sampling of key results that highlight both challenges and opportunities for integrated multiscale experiment and modelling in biological systems. PMID:28981126

  10. 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

  11. 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.

  12. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. 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

  15. Assessment of the Eu migration experiments and their modelling

    International Nuclear Information System (INIS)

    Klotz, D.

    2001-01-01

    The humic acid transport of heavy metals in underground water was investigated in laboratory experiments using the lanthanide Eu in the form of 152 Eu 3+ , which is both a model heavy metal and an indicator for assessing the potential hazards of ultimate storage sites for radioactive waste [de

  16. Breakthrough without subsidies? : PV business model experiments in the Netherlands.

    NARCIS (Netherlands)

    Huijben, J.C.C.M.; Verbong, G.P.J.

    2013-01-01

    Despite a lack of steady governmental support for PV in the Netherlands over the last decade, from 2008 onwards an increased number of initiatives started experimenting with new business models for PV. Though absolute numbers of installed capacity are still low, this is a promising sign. In this

  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. Vibrational kinetics in CO electric discharge lasers - Modeling and experiments

    Science.gov (United States)

    Stanton, A. C.; Hanson, R. K.; Mitchner, M.

    1980-01-01

    A model of CO laser vibrational kinetics is developed, and predicted vibrational distributions are compared with measurements. The experimental distributions were obtained at various flow locations in a transverse CW discharge in supersonic (M = 3) flow. Good qualitative agreement is obtained in the comparisons, including the prediction of a total inversion at low discharge current densities. The major area of discrepancy is an observed loss in vibrational energy downstream of the discharge which is not predicted by the model. This discrepancy may be due to three-dimensional effects in the experiment which are not included in the model. Possible kinetic effects which may contribute to vibrational energy loss are also examined.

  20. 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...... 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...

  1. Modelling and Experiments of a Standing Wave Piezomotor

    DEFF Research Database (Denmark)

    Helbo, Jan; Andersen, Brian; Blanke, Mogens

    2002-01-01

    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...... 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...

  2. 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

  3. Turkish experience with the use of IAEA planning models

    Energy Technology Data Exchange (ETDEWEB)

    Fikret, H [Ministry of Energy and Natural Resouces, Ankara (Turkey)

    1997-09-01

    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.

  4. 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.

  5. 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...... been modelled using a state-of-the-art model and compared with satisfying result to the performed experiments. The numerical model has been used for a parametric study, investigating the redistribution of residual stresses during the process of drilling. This is done for investigating the possibility...... 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....

  6. Equation of state experiments and theory relevant to planetary modelling

    International Nuclear Information System (INIS)

    Ross, M.; Graboske, H.C. Jr.; Nellis, W.J.

    1981-01-01

    In recent years there have been a number of static and shockwave experiments on the properties of planetary materials. The highest pressure measurements, and the ones most relevant to planetary modelling, have been obtained by shock compression. Of particular interest to the Jovian group are results for H 2 , H 2 O, CH 4 and NH 3 . Although the properties of metallic hydrogen have not been measured, they have been the subject of extensive calculations. In addition recent shock wave experiments on iron report to have detected melting under Earth core conditions. From this data theoretical models have been developed for computing the equations of state of materials used in planetary studies. A compelling feature that has followed from the use of improved material properties is a simplification in the planetary models. (author)

  7. 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

  8. 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)

  9. 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.

  10. 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)

  11. Modeling, analysis and experiments for fusion nuclear technology

    International Nuclear Information System (INIS)

    Abdou, M.A.; Hadid, A.H.; Raffray, A.R.; Tillack, M.S.; Iizuka, T.

    1988-01-01

    Selected issues in the development of fusion nuclear technology (FNT) have been studied. These relate to (1) near-term experiments, modeling, and analysis for several key FNT issues, and (2) FNT testing in future fusion facilities. A key concern for solid breeder blankets is to reduce the number of candidate materials and configurations for advanced experiments to emphasize those with the highest potential. Based on technical analysis, recommendations have been developed for reducing the size of the test matrix and for focusing the testing program on important areas of emphasis. The characteristics of an advanced liquid metal MHD experiment have also been studied. This facility is required in addition to existing facilities in order to address critical uncertainties in MHD fluid flow and heat transfer. In addition to experiments, successful development of FNT will require models for interpreting experimental data, for planning experiments, and for use as a design tool for fusion components. Modeling of liquid metal fluid flows is a particular area of need in which substantial progress is expected, and initial efforts are reported here. Preliminary results on the modeling of tritium transport and inventory in solid breeders are also summarized. Finally, the thermo-mechanical behavior of liquid-metal-cooled limiters is analyzed and the parameter space for feasible designs is explored. Because of the renewed strong interest in a fusion engineering facility, a critical review and analysis of the important FNT testing requirements have been performed. Several areas have been emphasized due to their strong impact on the design and cost of the test facility. These include (1) the length of the plasma burn and the mode of operation (pulsed vs. steady-state), and (2) the need for a tritium-producing blanket and its impact on the availability of the device. (orig.)

  12. 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

  13. Modeling and conduct of turbine missile concrete impact experiments

    International Nuclear Information System (INIS)

    Woodfin, R.L.

    1981-01-01

    The overall objective of the subject experiments was to provide full scale data on the response of reinforced concrete containment walls to impact and penetration by postulated turbine-produced missiles. These data can be used to validate analytical or scale modeling methods and to assess the applicability of current design formulas to penetration by large, irregularly shaped missiles. These data and results will be used in providing more realistic estimates of turbine missile damage probability in nuclear power plants with a non-peninsula arrangement. This paper describes the derivation of the test matrix and the method of conducting the experiments. (orig./HP)

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

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, B., E-mail: bcheng@lanl.gov; Kwan, T. J. T.; Wang, Y. M.; Merrill, F. E.; Batha, S. H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Cerjan, C. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2015-08-15

    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.

  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. Bayesian model calibration of ramp compression experiments on Z

    Science.gov (United States)

    Brown, Justin; Hund, Lauren

    2017-06-01

    Bayesian model calibration (BMC) is a statistical framework to estimate inputs for a computational model in the presence of multiple uncertainties, making it well suited to dynamic experiments which must be coupled with numerical simulations to interpret the results. Often, dynamic experiments are diagnosed using velocimetry and this output can be modeled using a hydrocode. Several calibration issues unique to this type of scenario including the functional nature of the output, uncertainty of nuisance parameters within the simulation, and model discrepancy identifiability are addressed, and a novel BMC process is proposed. As a proof of concept, we examine experiments conducted on Sandia National Laboratories' Z-machine which ramp compressed tantalum to peak stresses of 250 GPa. The proposed BMC framework is used to calibrate the cold curve of Ta (with uncertainty), and we conclude that the procedure results in simple, fast, and valid inferences. Sandia National Laboratories is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  17. Coolability of the melt in the reactor tank. A compilation and evaluation of the state of the art and suggestions for experiments in the area; Smaeltans kylbarhet i reaktortanken. En sammanstaellning och vaerdering av kunskapslaeget och foerslag till experiment inom omraadet

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Ferenc [ES-konsult Energi och Saekerhet AB, Stockholm (Sweden)

    2002-04-01

    This study is limited to experiments about phenomena and mechanisms that affect the coolability of core debris in the reactor tank that may delay the tank rupture. The goal of the study is to get an overview of the phenomena that are important for the in-vessel coolability, and to evaluate the need for new experiments. Both theoretical and experimental projects are suggested.

  18. 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

  19. 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

  20. Nb3Al insert experiment log book. 3rd experiment of CS model coil

    International Nuclear Information System (INIS)

    Sugimoto, Makoto; Koizumi, Norikiyo; Isono, Takaaki

    2002-10-01

    The cool down of CS model coil and Nb 3 Al insert was started on March 4, 2002. It took almost one month and immediately started coil charge since April 3, 2002. The charge test of Nb 3 Al insert and CS model coil was completed on May 2, 2002. All of the experiments including the warm up was also completed on May 30, 2002. In this campaign, total shot numbers were 102 and the size of the data file in the DAS (Data Acquisition System) was about 5.2 GB. This report is a database that consists of the log list and the log sheets of every shot. (author)

  1. Lowest Astronomical Tide in the North Sea derived from a vertically referenced shallow water model, and an assessment of its suggested sense of safety

    NARCIS (Netherlands)

    Slobbe, D.C.; Klees, R.; Verlaan, M.; Dorst, L.; Gerritsen, H.

    2012-01-01

    In this study, LAT will be modeled relative to a geoid, after which the ellipsoidal heights of LAT will be obtained by adding geoid heights to the modeled LAT values. The use of a geoid instead of MSL has the advantage that the former can be realized everywhere and does not leave a gap along the

  2. 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

  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 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...

  4. Early experiences building a software quality prediction model

    Science.gov (United States)

    Agresti, W. W.; Evanco, W. M.; Smith, M. C.

    1990-01-01

    Early experiences building a software quality prediction model are discussed. The overall research objective is to establish a capability to project a software system's quality from an analysis of its design. The technical approach is to build multivariate models for estimating reliability and maintainability. Data from 21 Ada subsystems were analyzed to test hypotheses about various design structures leading to failure-prone or unmaintainable systems. Current design variables highlight the interconnectivity and visibility of compilation units. Other model variables provide for the effects of reusability and software changes. Reported results are preliminary because additional project data is being obtained and new hypotheses are being developed and tested. Current multivariate regression models are encouraging, explaining 60 to 80 percent of the variation in error density of the subsystems.

  5. The Dependent Poisson Race Model and Modeling Dependence in Conjoint Choice Experiments

    Science.gov (United States)

    Ruan, Shiling; MacEachern, Steven N.; Otter, Thomas; Dean, Angela M.

    2008-01-01

    Conjoint choice experiments are used widely in marketing to study consumer preferences amongst alternative products. We develop a class of choice models, belonging to the class of Poisson race models, that describe a "random utility" which lends itself to a process-based description of choice. The models incorporate a dependence structure which…

  6. Modeling and experiments on tritium permeation in fusion reactor blankets

    Science.gov (United States)

    Holland, D. F.; Longhurst, G. R.

    The determination of tritium loss from helium-cooled fusion breeding blankets are discussed. The issues are: (1) applicability of present models to permeation at low tritium pressures; (2) effectiveness of oxide layers in reducing permeation; (3) effectiveness of hydrogen addition as a means to lower tritium permeation; and (4) effectiveness of conversion to tritiated water and subsequent trapping to reduce permeation. Theoretical models applicable to these issues are discussed, and results of experiments in two areas are presented; permeation of mixtures of hydrogen isotopes and conversion to tritiated water.

  7. Modeling and experiments on tritium permeation in fusion reactor blankets

    International Nuclear Information System (INIS)

    Holland, D.F.; Longhurst, G.R.

    1985-01-01

    Issues are discussed that are critical in determining tritium loss from helium-cooled fusion breeding blankets. These issues are: (a) applicability of present models to permeation at low tritium pressures, (b) effectiveness of oxide layers in reducing permeation, (c) effectiveness of hydrogen addition as a means to lower tritium permeation, and (d) effectiveness of conversion to tritiated water and subsequent trapping as a means to reduce permeation. The paper discusses theoretical models applicable to these issues, and presents results of experiments in two areas: permeation of mixtures of hydrogen isotopes and conversion to tritiated water

  8. 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

  9. Reference analysis of the signal + background model in counting experiments

    Science.gov (United States)

    Casadei, D.

    2012-01-01

    The model representing two independent Poisson processes, labelled as ``signal'' and ``background'' and both contributing additively to the total number of counted events, is considered from a Bayesian point of view. This is a widely used model for the searches of rare or exotic events in presence of a background source, as for example in the searches performed by high-energy physics experiments. In the assumption of prior knowledge about the background yield, a reference prior is obtained for the signal alone and its properties are studied. Finally, the properties of the full solution, the marginal reference posterior, are illustrated with few examples.

  10. Soil remediation by heat injection: Experiments and numerical modelling

    Energy Technology Data Exchange (ETDEWEB)

    Betz, C.; Emmert, M.; Faerber, A. [Univ. of Stuttgart (Germany)] [and others

    1995-03-01

    In order to understand physical processes of thermally enhanced soil vapor extraction methods in porous media the isothermal, multiphase formulation for the numerical model MUFTE will be extended by a non-isothermal, multiphase-multicomponent formulation. In order to verify the numerical model, comparison with analytical solutions for well defined problems will be carried out. To identify relevant processes and their interactions, the results of the simulation will be compared with well controlled experiments with sophisticated measurement equipment in three different scales. The aim is to compare the different numerical solution techniques namely Finite Element versus Integral Finite Difference technique as implemented in MUFTE and TOUGH2 [9] respectively.

  11. Analogue experiments as benchmarks for models of lava flow emplacement

    Science.gov (United States)

    Garel, F.; Kaminski, E. C.; Tait, S.; Limare, A.

    2013-12-01

    During an effusive volcanic eruption, the crisis management is mainly based on the prediction of lava flow advance and its velocity. The spreading of a lava flow, seen as a gravity current, depends on its "effective rheology" and on the effusion rate. Fast-computing models have arisen in the past decade in order to predict in near real time lava flow path and rate of advance. This type of model, crucial to mitigate volcanic hazards and organize potential evacuation, has been mainly compared a posteriori to real cases of emplaced lava flows. The input parameters of such simulations applied to natural eruptions, especially effusion rate and topography, are often not known precisely, and are difficult to evaluate after the eruption. It is therefore not straightforward to identify the causes of discrepancies between model outputs and observed lava emplacement, whereas the comparison of models with controlled laboratory experiments appears easier. The challenge for numerical simulations of lava flow emplacement is to model the simultaneous advance and thermal structure of viscous lava flows. To provide original constraints later to be used in benchmark numerical simulations, we have performed lab-scale experiments investigating the cooling of isoviscous gravity currents. The simplest experimental set-up is as follows: silicone oil, whose viscosity, around 5 Pa.s, varies less than a factor of 2 in the temperature range studied, is injected from a point source onto a horizontal plate and spreads axisymmetrically. The oil is injected hot, and progressively cools down to ambient temperature away from the source. Once the flow is developed, it presents a stationary radial thermal structure whose characteristics depend on the input flow rate. In addition to the experimental observations, we have developed in Garel et al., JGR, 2012 a theoretical model confirming the relationship between supply rate, flow advance and stationary surface thermal structure. We also provide

  12. 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.

  13. Numerical modeling of NI-monitored 3D infiltration experiment

    Science.gov (United States)

    Dohnal, Michal; Dusek, Jaromir; Snehota, Michal; Sacha, Jan; Vogel, Tomas; Votrubova, Jana

    2014-05-01

    It is well known that the temporal changes of saturated hydraulic conductivity caused by the occurrence of air phase discontinuities often play an important role in water flow and solute transport experiments. In the present study, a series of infiltration-outflow experiments was conducted to test several working hypotheses about the mechanism of air phase trapping. The experiments were performed on a porous sample with artificial internal structure, using three sandy materials with contrasting hydraulic properties. The sample was axially symmetric with continuous preferential pathways and separate porous matrix blocks (the sample was 3.4 cm in diameter and 8.8 cm high). The infiltration experiments were monitored by neutron imaging (NI). The NI data were then used to quantify the water content of the selected sample regions. The flow regime in the sample was studied using a three-dimensional model based on Richards' equation. The equation was solved by the finite element method. The results of the numerical simulations of the infiltration experiments were compared with the measured outflow rates and with the spatial distribution of water content determined by NI. The research was supported by the Czech Science Foundation Project No. 14-03691S.

  14. A Simulation Modeling Approach Method Focused on the Refrigerated Warehouses Using Design of Experiment

    Science.gov (United States)

    Cho, G. S.

    2017-09-01

    For performance optimization of Refrigerated Warehouses, design parameters are selected based on the physical parameters such as number of equipment and aisles, speeds of forklift for ease of modification. This paper provides a comprehensive framework approach for the system design of Refrigerated Warehouses. We propose a modeling approach which aims at the simulation optimization so as to meet required design specifications using the Design of Experiment (DOE) and analyze a simulation model using integrated aspect-oriented modeling approach (i-AOMA). As a result, this suggested method can evaluate the performance of a variety of Refrigerated Warehouses operations.

  15. 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

  16. Deuterium incorporation experiments from (3R)- and (3S)-[3-2H]leucine into characteristic isoprenoidal lipid-core of halophilic archaea suggests the involvement of isovaleryl-CoA dehydrogenase.

    Science.gov (United States)

    Yamauchi, Noriaki; Tanoue, Ryo

    2017-11-01

    The stereochemical reaction course for the two C-3 hydrogens of leucine to produce a characteristic isoprenoidal lipid in halophilic archaea was observed using incubation experiments with whole cell Halobacterium salinarum. Deuterium-labeled (3R)- and (3S)-[3- 2 H]leucine were freshly prepared as substrates from 2,3-epoxy-4-methyl-1-pentanol. Incorporation of deuterium from (3S)-[3- 2 H]leucine and loss of deuterium from (3R)-[3- 2 H]leucine in the lipid-core of H. salinarum was observed. Taken together with the results of our previous report, involving the incubation of chiral-labeled [5- 2 H]leucine, these results strongly suggested an involvement of isovaleryl-CoA dehydrogenase in leucine conversion to isoprenoid lipid in halophilic archaea. The stereochemical course of the reaction (anti-elimination) might have been the same as that previously reported for mammalian enzyme reactions. Thus, these results suggested that branched amino acids were metabolized to mevalonate in archaea in a manner similar to other organisms.

  17. EXPERIMENTS AND COMPUTATIONAL MODELING OF PULVERIZED-COAL IGNITION; FINAL

    International Nuclear Information System (INIS)

    Samuel Owusu-Ofori; John C. Chen

    1999-01-01

    Under typical conditions of pulverized-coal combustion, which is characterized by fine particles heated at very high rates, there is currently a lack of certainty regarding the ignition mechanism of bituminous and lower rank coals as well as the ignition rate of reaction. furthermore, there have been no previous studies aimed at examining these factors under various experimental conditions, such as particle size, oxygen concentration, and heating rate. Finally, there is a need to improve current mathematical models of ignition to realistically and accurately depict the particle-to-particle variations that exist within a coal sample. Such a model is needed to extract useful reaction parameters from ignition studies, and to interpret ignition data in a more meaningful way. The authors propose to examine fundamental aspects of coal ignition through (1) experiments to determine the ignition temperature of various coals by direct measurement, and (2) modeling of the ignition process to derive rate constants and to provide a more insightful interpretation of data from ignition experiments. The authors propose to use a novel laser-based ignition experiment to achieve their first objective. Laser-ignition experiments offer the distinct advantage of easy optical access to the particles because of the absence of a furnace or radiating walls, and thus permit direct observation and particle temperature measurement. The ignition temperature of different coals under various experimental conditions can therefore be easily determined by direct measurement using two-color pyrometry. The ignition rate-constants, when the ignition occurs heterogeneously, and the particle heating rates will both be determined from analyses based on these measurements

  18. 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.

  19. Exploration in free word association networks: models and experiment.

    Science.gov (United States)

    Ludueña, Guillermo A; Behzad, Mehran Djalali; Gros, Claudius

    2014-05-01

    Free association is a task that requires a subject to express the first word to come to their mind when presented with a certain cue. It is a task which can be used to expose the basic mechanisms by which humans connect memories. In this work, we have made use of a publicly available database of free associations to model the exploration of the averaged network of associations using a statistical and the adaptive control of thought-rational (ACT-R) model. We performed, in addition, an online experiment asking participants to navigate the averaged network using their individual preferences for word associations. We have investigated the statistics of word repetitions in this guided association task. We find that the considered models mimic some of the statistical properties, viz the probability of word repetitions, the distance between repetitions and the distribution of association chain lengths, of the experiment, with the ACT-R model showing a particularly good fit to the experimental data for the more intricate properties as, for instance, the ratio of repetitions per length of association chains.

  20. 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.!

  1. Resistive transition for two-dimensional superconductors: Comparison between experiments and Coulomb-gas-model predictions

    International Nuclear Information System (INIS)

    Minnhagen, P.

    1983-01-01

    The Coulomb-gas model of vortex fluctuations leads to scaling relations for the resistive transition which can be directly tested by experiments. By analyzing published resistance data, it is shown that there is experimental evidence for the Coulomb-gas scaling relation in the absence of a perpendicular magnetic field. It is also shown that there exists some suggestive support for the Coulomb-gas predictions in the presence of a magnetic field

  2. 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......, 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... 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...

  3. Experiment research on cognition reliability model of nuclear power plant

    International Nuclear Information System (INIS)

    Zhao Bingquan; Fang Xiang

    1999-01-01

    The objective of the paper is to improve the reliability of operation on real nuclear power plant of operators through the simulation research to the cognition reliability of nuclear power plant operators. The research method of the paper is to make use of simulator of nuclear power plant as research platform, to take present international research model of reliability of human cognition based on three-parameter Weibull distribution for reference, to develop and get the research model of Chinese nuclear power plant operators based on two-parameter Weibull distribution. By making use of two-parameter Weibull distribution research model of cognition reliability, the experiments about the cognition reliability of nuclear power plant operators have been done. Compared with the results of other countries such USA and Hungary, the same results can be obtained, which can do good to the safety operation of nuclear power plant

  4. Elucidating the role of recovery experiences in the job demands-resources model.

    Science.gov (United States)

    Moreno-Jiménez, Bernardo; Rodríguez-Muñoz, Alfredo; Sanz-Vergel, Ana Isabel; Garrosa, Eva

    2012-07-01

    Based on the Job Demands-Resources (JD-R) model, the current study examined the moderating role of recovery experiences (i.e., psychological detachment from work, relaxation, mastery experiences, and control over leisure time) on the relationship between one job demand (i.e., role conflict) and work- and health-related outcomes. Results from our sample of 990 employees from Spain showed that psychological detachment from work and relaxation buffered the negative impact of role conflict on some of the proposed outcomes. Contrary to our expectations, we did not find significant results for mastery and control regarding moderating effects. Overall, findings suggest a differential pattern of the recovery experiences in the health impairment process proposed by the JD-R model.

  5. 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.

  6. Beyond Performance: A Motivational Experiences Model of Stereotype Threat

    Science.gov (United States)

    Thoman, Dustin B.; Smith, Jessi L.; Brown, Elizabeth R.; Chase, Justin; Lee, Joo Young K.

    2013-01-01

    The contributing role of stereotype threat (ST) to learning and performance decrements for stigmatized students in highly evaluative situations has been vastly documented and is now widely known by educators and policy makers. However, recent research illustrates that underrepresented and stigmatized students’ academic and career motivations are influenced by ST more broadly, particularly through influences on achievement orientations, sense of belonging, and intrinsic motivation. Such a focus moves conceptualizations of ST effects in education beyond the influence on a student’s performance, skill level, and feelings of self-efficacy per se to experiencing greater belonging uncertainty and lower interest in stereotyped tasks and domains. These negative experiences are associated with important outcomes such as decreased persistence and domain identification, even among students who are high in achievement motivation. In this vein, we present and review support for the Motivational Experience Model of ST, a self-regulatory model framework for integrating research on ST, achievement goals, sense of belonging, and intrinsic motivation to make predictions for how stigmatized students’ motivational experiences are maintained or disrupted, particularly over long periods of time. PMID:23894223

  7. Consultation and illness behaviour in response to symptoms: A comparison of models from different disciplinary frameworks and suggestions for future research directions

    NARCIS (Netherlands)

    Wyke, S.; Adamson, J.; Dixon, D.; Hunt, K.

    2013-01-01

    We all get ill and social scientific interest in how we respond - the study of illness behaviour - continues unabated. Existing models are useful, but have been developed and applied within disciplinary silos, resulting in wasted intellectual and empirical effort and an absence of accumulation of

  8. 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 measur...... 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.......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...... 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...

  9. 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

  10. Modeling, simulation, and experiments of coating growth on nanofibers

    International Nuclear Information System (INIS)

    Clemons, C. B.; Hamrick, P.; Heminger, J.; Kreider, K. L.; Young, G. W.; Buldum, A.; Evans, E.; Zhang, G.

    2008-01-01

    This work is a comparison of modeling and simulation results with experiments for an integrated experimental/modeling investigation of a procedure to coat nanofibers and core-clad nanostructures with thin film materials using plasma enhanced physical vapor deposition. In the experimental effort, electrospun polymer nanofibers are coated with metallic materials under different operating conditions to observe changes in the coating morphology. The modeling effort focuses on linking simple models at the reactor level, nanofiber level and atomic level to form a comprehensive model. The comprehensive model leads to the definition of an evolution equation for the coating free surface around an isolated nanofiber. This evolution equation was previously derived and solved under conditions of a nearly circular coating, with a concentration field that was only radially dependent and that was independent of the location of the coating free surface. These assumptions permitted the development of analytical expressions for the concentration field. The present work does not impose the above-mentioned conditions and considers numerical simulations of the concentration field that couple with level set simulations of the evolution equation for the coating free surface. Further, the cases of coating an isolated fiber as well as a multiple fiber mat are considered. Simulation results are compared with experimental results as the reactor pressure and power, as well as the nanofiber mat porosity, are varied

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. Uterus transplantation: Experimental animal models and recent experience in humans

    Directory of Open Access Journals (Sweden)

    Sadık Şahin

    2015-03-01

    Full Text Available Uterus transplantation has been considered as an alternative management modality in the last few years for adoption or gestational surrogacy for women with absence of uterus due to congenital or acquired reasons. Surrogacy is legal in only a few countries because of ethical, social and legal issues. Up to date, a total of 11 uterus transplantation cases have been reported in which uteri were harvested from ten live donors and one donor with brain death. After unsuccessful attempt of first uterus transplantation, many studies have been conducted in animals and these experimental models enabled our knowledge to increase on this topic. First experimental studies were performed in rodents; later uterus transplantation was accomplished in sheep, pigs and rabbits. Recently, researches in non-human primates have led the experience regarding transplantation technique and success to improve. In this review, we reviewed the experimental animal researches in the area of uterus transplantation and recent experience in humans.

  16. Rasch models suggested the satisfactory psychometric properties of the World Health Organization Quality of Life-Brief among lung cancer patients.

    Science.gov (United States)

    Lin, Chung-Ying; Yang, Szu-Chun; Lai, Wu-Wei; Su, Wu-Chou; Wang, Jung-Der

    2017-03-01

    The study examined whether the items of the World Health Organization Quality of Life-Brief questionnaire can assess its four underlying domains (Physical, Psychological, Social, and Environment) in a sample of lung cancer patients. All patients ( n = 1150) were recruited from a medical center in Tainan, and each participant completed the World Health Organization Quality of Life-Brief. Several Rasch rating scale models were used to examine the data-model fit, and Rasch analyses corroborated that each domain of the World Health Organization Quality of Life-Brief could be unidimensional. Although three items were found to have a poor fit, all the other items fit the unidimensionality with ordered thresholds.

  17. Analytic models of NH4+ uptake and regeneration experiments

    International Nuclear Information System (INIS)

    Laws, E.A.

    1985-01-01

    Differential equations describing the uptake and regeneration of NH 4 + in both laboratory and field experiments are shown to have analytic solutions which can easily be inverted to determine the rate constants of interest. The solutions are used to study the descriptive ability of two fundamentally different models of NH 4 + cycling, one in which NH 4 + regeneration is regarded as a process that transfers N from participate N to NH 4 + , the other in which regeneration is regarded as a process that introduced NH 4 + to the dissolved phase without removing N from the particulate phase. The former model was found to give a good description of experimental field data and reasonable parameter values in all cases studied. The latter model was much less successful in describing the data and in producing reasonable parameter values. It is concluded that transfer of nitrogen from particulate N to NH 4 + is a process which must be taken into account in analyzing NH 4 + uptake and regeneration experiments

  18. 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.

  19. Double tracer experiments to evaluate atmospheric transport and dose models

    International Nuclear Information System (INIS)

    Nielsen, S.P.; Gryning, S.-E.; Thykier-Nielsen, S.; Karlberg, O.; Lyck, E.

    1986-05-01

    Two tracers, sulphurhexafluoride (SF 6 ) and radioactive noble gases, were released simultaneously from a 110-m stack and detected downwind at distances of 3-4 km. The experiments were made at the Swedish nuclear power plant Ringhals in 1981. The radioactive tracer was routine emissions from unit 1 (BWR). The one-hour measurements yielded crosswind profiles at ground level of SF 6 -concentrations and of gamma radiation from the plume. The measured profiles were compared to profiles calculated with computer models. The comparison showed that the models sometimes underestimate and sometimes overestimate the results, which seems to indicate that the models within their limited accuracy yield unbiased results. The ratios between measured and calculated values range from 0.2 to 3. The measurements revealed a surplus of gamma radiations from the noble gas daughters compared to those from the gases. This was interpreted as due to ground desposition and the estimated deposition velocities range from 2 to 10 cm/s. The meteorological conditions were monitored from a 100-m meteorological tower and from an 11-m mast. Measurements were made of wind speed, wind direction, and temperatures at different heights, and during each experiment a mini-radiosonde was released giving information on a possible inversion layer. The SF 6 -tracer was injected to the stack prior to the experiments. Air-samples were collected downwind in plastic bags by radio-controlled sampling units. The SF 6 -concentrations in the bags were determined with gas chromatography. Measurements of the gamma radiation from the plume were made with ionisation chambers and GM-counters. Furthermore, a few mobile gamma spectrometers were available giving information on the unscattered gamma radiation, thereby permitting identification of the radioactive isotopes. The work was partly financed by the Nuclear Safety Board of the Swedish Utilities and by the Danish association of utilities in Jutland and on Funen, Elsam

  20. 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

  1. 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.

  2. 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.

  3. Experiments of reconstructing discrete atmospheric dynamic models from data (I)

    Science.gov (United States)

    Lin, Zhenshan; Zhu, Yanyu; Deng, Ziwang

    1995-03-01

    In this paper, we give some experimental results of our study in reconstructing discrete atmospheric dynamic models from data. After a great deal of numerical experiments, we found that the logistic map, x n + 1 = 1- μx {2/n}, could be used in monthly mean temperature prediction when it was approaching the chaotic region, and its predictive results were in reverse states to the practical data. This means that the nonlinear developing behavior of the monthly mean temperature system is bifurcating back into the critical chaotic states from the chaotic ones.

  4. 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

  5. Behaviour modelling of two aluminas in divergent spherical pyrotechnical experiments

    International Nuclear Information System (INIS)

    Malaise, F.; Tranchet, J.Y.; Collombet, F.

    1997-01-01

    Two pure aluminas of different characteristics have been subjected to the propagation of a longitudinal divergent spherical shock wave through pyrotechnical experiments. An approach combining a phenomenological analysis and numerical 1D-calculations is proposed to study the behaviour of these aluminas submitted to that type of wave loading. The modelling, proposed in a previous paper, is refined and gives satisfying experimentation-calculation correlations. An analysis of the influence exerted by the various encountered phenomena (plastic activity, pore closure, microcracking) is performed. The significant consequence of the activation of damage with an extension criterion is also underlined. (orig.)

  6. Modeling of N2 and O optical emissions for ionosphere HF powerful heating experiments

    Science.gov (United States)

    Sergienko, T.; Gustavsson, B.

    Analyses of experiments of F region ionosphere modification by HF powerful radio waves show that optical observations are very useful tools for diagnosing of the interaction of the probing radio wave with the ionospheric plasma Hitherto the emissions usually measured in the heating experiment have been the 630 0 nm and the 557 7 nm lines of atomic oxygen Other emissions for instance O 844 8 nm and N2 427 8 nm have been measured episodically in only a few experiments although the very rich optical spectrum of molecular nitrogen potentially involves important information about ionospheric plasma in the heated region This study addresses the modeling of optical emissions from the O and the N2 triplet states first positive second positive Vegard-Kaplan infrared afterglow and Wu-Benesch band systems excited under a condition of the ionosphere heating experiment The auroral triplet state population distribution model was modified for the ionosphere heating conditions by using the different electron distribution functions suggested by Mishin et al 2000 2003 and Gustavsson at al 2004 2005 Modeling results are discussed from the point of view of efficiency of measurements of the N2 emissions in future experiments

  7. 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.

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

    International Nuclear Information System (INIS)

    Amadio, G; Bianchini, C; Apostolakis, J; Bitzes, G; Brun, R; Carminati, F; Gheata, A; Novak, M; Shadura, O; Wenzel, S; Bandieramonte, M; Canal, P; Elvira, D; Jun, S Y; Lima, G; Licht, J de Fine; Duhem, L; Presbyterian, M; Seghal, R

    2015-01-01

    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. (paper)

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

    Science.gov (United States)

    Amadio, G.; Apostolakis, J.; Bandieramonte, M.; Bianchini, C.; Bitzes, G.; Brun, R.; Canal, P.; Carminati, F.; de Fine Licht, J.; Duhem, L.; Elvira, D.; Gheata, A.; Jun, S. Y.; Lima, G.; Novak, M.; Presbyterian, M.; Shadura, O.; Seghal, R.; Wenzel, S.

    2015-12-01

    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.

  10. 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.

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    Christa Nilsen

    Full Text Available 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.

  13. The influence of suggestibility on memory.

    Science.gov (United States)

    Nicolas, Serge; Collins, Thérèse; Gounden, Yannick; Roediger, Henry L

    2011-06-01

    We provide a translation of Binet and Henri's pioneering 1894 paper on the influence of suggestibility on memory. Alfred Binet (1857-1911) is famous as the author who created the IQ test that bears his name, but he is almost unknown as the psychological investigator who generated numerous original experiments and fascinating results in the study of memory. His experiments published in 1894 manipulated suggestibility in several ways to determine effects on remembering. Three particular modes of suggestion were employed to induce false recognitions: (1) indirect suggestion by a preconceived idea; (2) direct suggestion; and (3) collective suggestion. In the commentary we suggest that Binet and Henri's (1894) paper written over 115 years ago is still highly relevant even today. In particular, Binet's legacy lives on in modern research on misinformation effects in memory, in studies of conformity, and in experiments on the social contagion of memory. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. 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.

  15. Neuroprotective effects of the anti-cancer drug sunitinib in models of HIV neurotoxicity suggests potential for the treatment of neurodegenerative disorders.

    Science.gov (United States)

    Wrasidlo, Wolf; Crews, Leslie A; Tsigelny, Igor F; Stocking, Emily; Kouznetsova, Valentina L; Price, Diana; Paulino, Amy; Gonzales, Tania; Overk, Cassia R; Patrick, Christina; Rockenstein, Edward; Masliah, Eliezer

    2014-12-01

    Anti-retrovirals have improved and extended the life expectancy of patients with HIV. However, as this population ages, the prevalence of cognitive changes is increasing. Aberrant activation of kinases, such as receptor tyrosine kinases (RTKs) and cyclin-dependent kinase 5 (CDK5), play a role in the mechanisms of HIV neurotoxicity. Inhibitors of CDK5, such as roscovitine, have neuroprotective effects; however, CNS penetration is low. Interestingly, tyrosine kinase inhibitors (TKIs) display some CDK inhibitory activity and ability to cross the blood-brain barrier. We screened a small group of known TKIs for a candidate with additional CDK5 inhibitory activity and tested the efficacy of the candidate in in vitro and in vivo models of HIV-gp120 neurotoxicity. Among 12 different compounds, sunitinib inhibited CDK5 with an IC50 of 4.2 μM. In silico analysis revealed that, similarly to roscovitine, sunitinib fitted 6 of 10 features of the CDK5 pharmacophore. In a cell-based model, sunitinib reduced CDK5 phosphorylation (pCDK5), calpain-dependent p35/p25 conversion and protected neuronal cells from the toxic effects of gp120. In glial fibrillary acidic protein-gp120 transgenic (tg) mice, sunitinib reduced levels of pCDK5, p35/p25 and phosphorylated tau protein, along with amelioration of the neurodegenerative pathology. Compounds such as sunitinib with dual kinase inhibitory activity could ameliorate the cognitive impairment associated with chronic HIV infection of the CNS. Moreover, repositioning existing low MW compounds holds promise for the treatment of patients with neurodegenerative disorders. © 2014 The British Pharmacological Society.

  16. Physiologically based pharmacokinetic modeling of human exposure to perfluorooctanoic acid suggests historical non drinking-water exposures are important for predicting current serum concentrations.

    Science.gov (United States)

    Worley, Rachel Rogers; Yang, Xiaoxia; Fisher, Jeffrey

    2017-09-01

    Manufacturing of perfluorooctanoic acid (PFOA), a synthetic chemical with a long half-life in humans, peaked between 1970 and 2002, and has since diminished. In the United States, PFOA is detected in the blood of >99% of people tested, but serum concentrations have decreased since 1999. Much is known about exposure to PFOA in drinking water; however, the impact of non-drinking water PFOA exposure on serum PFOA concentrations is not well characterized. The objective of this research is to apply physiologically based pharmacokinetic (PBPK) modeling and Monte Carlo analysis to evaluate the impact of historic non-drinking water PFOA exposure on serum PFOA concentrations. In vitro to in vivo extrapolation was utilized to inform descriptions of PFOA transport in the kidney. Monte Carlo simulations were incorporated to evaluate factors that account for the large inter-individual variability of serum PFOA concentrations measured in individuals from North Alabama in 2010 and 2016, and the Mid-Ohio River Valley between 2005 and 2008. Predicted serum PFOA concentrations were within two-fold of experimental data. With incorporation of Monte Carlo simulations, the model successfully tracked the large variability of serum PFOA concentrations measured in populations from the Mid-Ohio River Valley. Simulation of exposure in a population of 45 adults from North Alabama successfully predicted 98% of individual serum PFOA concentrations measured in 2010 and 2016, respectively, when non-drinking water ingestion of PFOA exposure was included. Variation in serum PFOA concentrations may be due to inter-individual variability in the disposition of PFOA and potentially elevated historical non-drinking water exposures. Published by Elsevier Inc.

  17. 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.

  18. Mass Spectrometry Coupled Experiments and Protein Structure Modeling Methods

    Directory of Open Access Journals (Sweden)

    Lee Sael

    2013-10-01

    Full Text Available With the accumulation of next generation sequencing data, there is increasing interest in the study of intra-species difference in molecular biology, especially in relation to disease analysis. Furthermore, the dynamics of the protein is being identified as a critical factor in its function. Although accuracy of protein structure prediction methods is high, provided there are structural templates, most methods are still insensitive to amino-acid differences at critical points that may change the overall structure. Also, predicted structures are inherently static and do not provide information about structural change over time. It is challenging to address the sensitivity and the dynamics by computational structure predictions alone. However, with the fast development of diverse mass spectrometry coupled experiments, low-resolution but fast and sensitive structural information can be obtained. This information can then be integrated into the structure prediction process to further improve the sensitivity and address the dynamics of the protein structures. For this purpose, this article focuses on reviewing two aspects: the types of mass spectrometry coupled experiments and structural data that are obtainable through those experiments; and the structure prediction methods that can utilize these data as constraints. Also, short review of current efforts in integrating experimental data in the structural modeling is provided.

  19. Design and modeling of precision solid liner experiments on Pegasus

    International Nuclear Information System (INIS)

    Bowers, R.L.; Brownell, J.H.; Lee, H.; McLenithan, K.D.; Scannapieco, A.J.; Shanahan, W.R.

    1998-01-01

    Pulsed power driven solid liners may be used for a variety of physics experiments involving materials at high stresses. These include shock formation and propagation, material strain-rate effects, material melt, instability growth, and ejecta from shocked surfaces. We describe the design and performance of a cylindrical solid liner that can attain velocities in the several mm/μs regime, and that can be used to drive high-stress experiments. An approximate theoretical analysis of solid liner implosions is used to establish the basic parameters (mass, materials, and initial radius) of the driver. We then present one-dimensional and two-dimensional simulations of magnetically driven, liner implosions which include resistive heating and elastic endash plastic behavior. The two-dimensional models are used to study the effects of electrode glide planes on the liner close-quote s performance, to examine sources of perturbations of the liner, and to assess possible effects of instability growth during the implosion. Finally, simulations are compared with experimental data to show that the solid liner performed as predicted computationally. Experimental data indicate that the liner imploded from an initial radius of 2.4 cm to a target radius of 1.5 cm, and that it was concentric and cylindrical to better than the experimental resolution (60 μm) at the target. The results demonstrate that a precision solid liner can be produced for high-stress, pulsed power applications experiments. copyright 1998 American Institute of Physics

  20. PLN's experience with the WASP-III model in generation expansion planning for the Java system

    International Nuclear Information System (INIS)

    Sudja, N.; Afiff, A.; Simarmata, B.

    1988-01-01

    The State Electric Power Corporation of Indonesia (PLN) was one of the first recipients of the WASP computer model, and since 1976 has been using the model (first the version WASP-II, and later the WASP-III version) for carrying out generation expansion planning studies for the country, and particularly, for the Java power system. This paper discusses PLN's experience with WASP-III and comments on some problems and constraints encountered, particularly: the time-fixed forced outage rate (FOR) assumed for generating units, simulation of the hydro system and computation time. The paper concludes with some suggestions about future enhancements to WASP-III. (author). 3 figs, 11 tabs

  1. Numerical modeling of plasma plume evolution against ambient background gas in laser blow off experiments

    International Nuclear Information System (INIS)

    Patel, Bhavesh G.; Das, Amita; Kaw, Predhiman; Singh, Rajesh; Kumar, Ajai

    2012-01-01

    Two dimensional numerical modelling based on simplified hydrodynamic evolution for an expanding plasma plume (created by laser blow off) against an ambient background gas has been carried out. A comparison with experimental observations shows that these simulations capture most features of the plasma plume expansion. The plume location and other gross features are reproduced as per the experimental observation in quantitative detail. The plume shape evolution and its dependence on the ambient background gas are in good qualitative agreement with the experiment. This suggests that a simplified hydrodynamic expansion model is adequate for the description of plasma plume expansion.

  2. 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)

  3. 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

  4. Experiences in applying Bayesian integrative models in interdisciplinary modeling: the computational and human challenges

    DEFF Research Database (Denmark)

    Kuikka, Sakari; Haapasaari, Päivi Elisabet; Helle, Inari

    2011-01-01

    We review the experience obtained in using integrative Bayesian models in interdisciplinary analysis focusing on sustainable use of marine resources and environmental management tasks. We have applied Bayesian models to both fisheries and environmental risk analysis problems. Bayesian belief...... be time consuming and research projects can be difficult to manage due to unpredictable technical problems related to parameter estimation. Biology, sociology and environmental economics have their own scientific traditions. Bayesian models are becoming traditional tools in fisheries biology, where...

  5. A comparative modeling study of a dual tracer experiment in a large lysimeter under atmospheric conditions

    Science.gov (United States)

    Stumpp, C.; Nützmann, G.; Maciejewski, S.; Maloszewski, P.

    2009-09-01

    SummaryIn this paper, five model approaches with different physical and mathematical concepts varying in their model complexity and requirements were applied to identify the transport processes in the unsaturated zone. The applicability of these model approaches were compared and evaluated investigating two tracer breakthrough curves (bromide, deuterium) in a cropped, free-draining lysimeter experiment under natural atmospheric boundary conditions. The data set consisted of time series of water balance, depth resolved water contents, pressure heads and resident concentrations measured during 800 days. The tracer transport parameters were determined using a simple stochastic (stream tube model), three lumped parameter (constant water content model, multi-flow dispersion model, variable flow dispersion model) and a transient model approach. All of them were able to fit the tracer breakthrough curves. The identified transport parameters of each model approach were compared. Despite the differing physical and mathematical concepts the resulting parameters (mean water contents, mean water flux, dispersivities) of the five model approaches were all in the same range. The results indicate that the flow processes are also describable assuming steady state conditions. Homogeneous matrix flow is dominant and a small pore volume with enhanced flow velocities near saturation was identified with variable saturation flow and transport approach. The multi-flow dispersion model also identified preferential flow and additionally suggested a third less mobile flow component. Due to high fitting accuracy and parameter similarity all model approaches indicated reliable results.

  6. Numerical modeling of the plasma ring acceleration experiment

    International Nuclear Information System (INIS)

    Eddleman, J.L.; Hammer, J.H.; Hartman, C.W.

    1987-01-01

    Modeling of the LLNL RACE experiment and its many applications has necessitated the development and use of a wide array of computational tools. The two-dimensional MHD code, HAM, has been used to model the formation of a compact torus plasma ring in a magnetized coaxial gun and its subsequent acceleration by an additional applied toroidal field. Features included in the 2-D calculations are self-consistent models for (1) the time-dependent poloidal field produced by a capacitor bank discharge through a solenoid field coil (located either inside the gun inner electrode or outside the outer gun electrode) and the associated diffusion of magnetic flux through neighboring conductors, (2) gas flow into the gun annular region from a simulated puffed gas valve plenum, (3) formation and motion of a current sheet produced by J x B forces resulting from discharge of the gun capacitor bank through the plasma load between the coaxial gun electrodes, (4) the subsequent stretching and reconnection of the poloidal field lines to form a compact torus plasma ring, and (5) finally the discharge of the accelerator capacitor bank producing an additional toroidal field for acceleration of the plasma ring. The code has been extended to include various models for gas breakdown, plasma anomalous resistivity, and mass entrainment from ablation of electrode material

  7. 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.

  8. 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.

  9. 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.

  10. Rogue waves in a water tank: Experiments and modeling

    Science.gov (United States)

    Lechuga, Antonio

    2013-04-01

    Recently many rogue waves have been reported as the main cause of ship incidents on the sea. One of the main characteristics of rogue waves is its elusiveness: they present unexpectedly and disappear in the same wave. Some authors (Zakharov and al.2010) are attempting to find the probability of their appearances apart from studyingthe mechanism of the formation. As an effort on this topic we tried the generation of rogue waves in a water wave tank using a symmetric spectrum(Akhmediev et al. 2011) as input on the wave maker. The produced waves were clearly rogue waves with a rate (maximum wave height/ Significant wave height) of 2.33 and a kurtosis of 4.77 (Janssen 2003, Onorato 2006). These results were already presented (Lechuga 2012). Similar waves (in pattern aspect, but without being extreme waves) were described as crossing waves in a water tank(Shemer and Lichter1988). To go on further the next step has been to apply a theoretical model to the envelope of these waves. After some considerations the best model has been an analogue of the Ginzburg-Landau equation. This apparently amazing result is easily explained: We know that the Ginzburg-Landau model is related to some regular structures on the surface of a liquid and also in plasmas, electric and magnetic fields and other media. Another important characteristic of the model is that their solutions are invariants with respectto the translation group. The main aim of this presentation is to extract conclusions of the model and the comparison with the measured waves in the water tank.The nonlinear structure of waves and their regularity make suitable the use of the Ginzburg-Landau model to the envelope of generated waves in the tank,so giving us a powerful tool to cope with the results of our experiment.

  11. 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.

  12. Half-Life of Sulfonylureas in HNF1A and HNF4A Human MODY Patients is not Prolonged as Suggested by the Mouse Hnf1a(-/-) Model.

    Science.gov (United States)

    Urbanova, Jana; Andel, Michal; Potockova, Jana; Klima, Josef; Macek, Jan; Ptacek, Pavel; Mat'oska, Vaclav; Kumstyrova, Tereza; Heneberg, Petr

    2015-01-01

    Sulfonylurea derivatives are widely used for clinical treatment of human subjects with Maturity Onset Diabetes of the Young (MODY) caused by mutations in HNF-1α or HNF-4α despite the mechanism leading to their hypersensitivity is incompletely understood. In Hnf1a(-/-) mice, serum concentrations and half-life of sulfonylurea derivatives are strongly increased. We thus hypothesized that reduced sulfonylurea derivatives clearance stands behind their therapeutic potential in human HNF1A/HNF4A MODY subjects. Single doses of 3 mg glipizide and 5 mg glibenclamide/glyburide were administered sequentially to seven HNF1A/HNF4A MODY subjects and six control individuals matched for their age, BMI and CYP2C9 genotype. Pharmacokinetic (plasma concentration levels, Cmax, tmax, t1/2, AUC) and pharmacodynamic parameters (glycemia, C-peptide and insulin plasma levels) were followed for 24 hours after drug administration. We provide the first evidence on the pharmacokinetics and pharmacodynamics of sulfonylurea derivatives in human MODY subjects. The half-life of glipizide did not change, and reached 3.8±0.7 and 3.7±1.8 h in the MODY and control subjects, respectively. The half-life of glibenclamide was increased only in some MODY subjects (t1/2 9.5±6.7 and 5.0±1.4 h, respectively). Importantly, the intra- individual responses of MODY (but control) subjects to glipizide and glibenclamide treatment were highly correlated. With regards to pharmacodynamics, we observed a differential response of control but not MODY subjects to the doses of glipizide and glibenclamide applied. We rejected the hypothesis that all human MODY-associated mutations in HNF1A / HNF4A induce changes in the pharmacokinetics of sulfonylureas in humans analogically to the Hnf1a(-/-) mouse model.

  13. 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.

  14. 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.

  15. 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.

  16. 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 ...

  17. 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

  18. 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

  19. 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.

  20. 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

  1. Types of suggestibility: Relationships among compliance, indirect, and direct suggestibility.

    Science.gov (United States)

    Polczyk, Romuald; Pasek, Tomasz

    2006-10-01

    It is commonly believed that direct suggestibility, referring to overt influence, and indirect suggestibility, in which the intention to influence is hidden, correlate poorly. This study demonstrates that they are substantially related, provided that they tap similar areas of influence. Test results from 103 students, 55 women and 48 men, were entered into regression analyses. Indirect suggestibility, as measured by the Sensory Suggestibility Scale for Groups, and compliance, measured by the Gudjonsson Compliance Scale, were predictors of direct suggestibility, assessed with the Barber Suggestibility Scale. Spectral analyses showed that indirect suggestibility is more related to difficult tasks on the BSS, but compliance is more related to easy tasks on this scale.

  2. 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.

  3. 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

  4. 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.

  5. Effective media models for unsaturated fractured rock: A field experiment

    International Nuclear Information System (INIS)

    Nicholl, M.J.; Glass, R.J.

    1995-01-01

    A thick unsaturated rock mass at Yucca Mountain is currently under consideration as a potential repository site for disposal of high level radioactive waste. In accordance with standard industry and scientific practices, abstract numerical models will be used to evaluate the potential for radionuclide release through the groundwater system. At this time, currently available conceptual models used to develop effective media properties are based primarily on simplistic considerations. The work presented here is part of an integrated effort to develop effective media models at the intermediate block scale (approximately 8-125m) through a combination of physical observations, numerical simulations and theoretical considerations. A multi-purpose field experiment designed and conducted as part of this integrated effort is described. Specific goals of this experimental investigation were to: (1) obtain fracture network data from Topopah Spring Tuff for use in block scale simulations; (2) identity positions of the network conducting flow under three different boundary conditions; (3) visualize preferential flow paths and small-scale flow structures; (4) collect samples for subsequent hydraulic testing and use in block-scale simulations; and (5) demonstrate the ability of Electrical Resistance Tomography (ERT) to delineate fluid distribution within fractured rock

  6. The effect of posthypnotic suggestion, hypnotic suggestibility, and goal intentions on adherence to medical instructions.

    Science.gov (United States)

    Carvalho, Claudia; Mazzoni, Giuliana; Kirsch, Irving; Meo, Maria; Santandrea, Maura

    2008-04-01

    The effects of implementation intentions and posthypnotic suggestion were investigated in 2 studies. In Experiment 1, participants with high levels of hypnotic suggestibility were instructed to take placebo pills as part of an investigation of how to best enhance compliance with medical instruction. In Experiment 2, participants with high, medium, and low levels of hypnotic suggestibility were asked to run in place, take their pulse rate before, and send an e-mail report to the experimenter each day. Experiment 1 revealed enhanced adherence as a function of both implementation intentions and posthypnotic suggestion. Experiment 2 failed to find any significant main effects but found a significant interaction between suggestibility and the effects of posthypnotic suggestion. Posthypnotic suggestion enhanced adherence among high suggestible participants but lowered it among low suggestibles.

  7. 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.

  8. Computer modeling of active experiments in space plasmas

    International Nuclear Information System (INIS)

    Bollens, R.J.

    1993-01-01

    The understanding of space plasmas is expanding rapidly. This is, in large part, due to the ambitious efforts of scientists from around the world who are performing large scale active experiments in the space plasma surrounding the earth. One such effort was designated the Active Magnetospheric Particle Tracer Explorers (AMPTE) and consisted of a series of plasma releases that were completed during 1984 and 1985. What makes the AMPTE experiments particularly interesting was the occurrence of a dramatic anomaly that was completely unpredicted. During the AMPTE experiment, three satellites traced the solar-wind flow into the earth's magnetosphere. One satellite, built by West Germany, released a series of barium and lithium canisters that were detonated and subsequently photo-ionized via solar radiation, thereby creating an artificial comet. Another satellite, built by Great Britain and in the vicinity during detonation, carried, as did the first satellite, a comprehensive set of magnetic field, particle and wave instruments. Upon detonation, what was observed by the satellites, as well as by aircraft and ground-based observers, was quite unexpected. The initial deflection of the ion clouds was not in the ambient solar wind's flow direction (rvec V) but rather in the direction transverse to the solar wind and the background magnetic field (rvec V x rvec B). This result was not predicted by any existing theories or simulation models; it is the main subject discussed in this dissertation. A large three dimensional computer simulation was produced to demonstrate that this transverse motion can be explained in terms of a rocket effect. Due to the extreme computer resources utilized in producing this work, the computer methods used to complete the calculation and the visualization techniques used to view the results are also discussed

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

    International Nuclear Information System (INIS)

    Bourret, Suzanne Michelle; Stauffer, Philip H.; Weaver, Douglas James; Caporuscio, Florie Andre; Otto, Shawn; Boukhalfa, Hakim; Jordan, Amy B.; Chu, Shaoping; Zyvoloski, George Anthony; Johnson, Peter Jacob

    2017-01-01

    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.

  10. 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.

  11. The BaBar experiment's distributed computing model

    International Nuclear Information System (INIS)

    Boutigny, D.

    2001-01-01

    In order to face the expected increase in statistics between now and 2005, the BaBar experiment at SLAC is evolving its computing model toward a distributed multitier system. It is foreseen that data will be spread among Tier-A centers and deleted from the SLAC center. A uniform computing environment is being deployed in the centers, the network bandwidth is continuously increased and data distribution tools has been designed in order to reach a transfer rate of ∼100 TB of data per year. In parallel, smaller Tier-B and C sites receive subsets of data, presently in Kanga-ROOT format and later in Objectivity format. GRID tools will be used for remote job submission

  12. A model surveillance program based on regulatory experience

    International Nuclear Information System (INIS)

    Conte, R.J.

    1980-01-01

    A model surveillance program is presented based on regulatory experience. The program consists of three phases: Program Delineation, Data Acquistion and Data Analysis. Each phase is described in terms of key quality assurance elements and some current philosophies is the United States Licensing Program. Other topics include the application of these ideas to test equipment used in the surveillance progam and audits of the established program. Program Delineation discusses the establishment of administrative controls for organization and the description of responsibilities using the 'Program Coordinator' concept, with assistance from Data Acquisition and Analysis Teams. Ideas regarding frequency of surveillance testing are also presented. The Data Acquisition Phase discusses various methods for acquiring data including operator observations, test procedures, operator logs, and computer output, for trending equipment performance. The Data Analysis Phase discusses the process for drawing conclusions regarding component/equipment service life, proper application, and generic problems through the use of trend analysis and failure rate data. (orig.)

  13. 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.

  14. The BaBar Experiment's Distributed Computing Model

    International Nuclear Information System (INIS)

    Gowdy, Stephen J.

    2002-01-01

    In order to face the expected increase in statistics between now and 2005, the BaBar experiment at SLAC is evolving its computing model toward a distributed multi-tier system. It is foreseen that data will be spread among Tier-A centers and deleted from the SLAC center. A uniform computing environment is being deployed in the centers, the network bandwidth is continuously increased and data distribution tools has been designed in order to reach a transfer rate of ∼100 TB of data per year. In parallel, smaller Tier-B and C sites receive subsets of data, presently in Kanga-ROOT[1] format and later in Objectivity[2] format. GRID tools will be used for remote job submission

  15. 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.

  16. 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.

  17. 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

  18. Vibration behavior of PWR reactor internals Model experiments and analysis

    International Nuclear Information System (INIS)

    Assedo, R.; Dubourg, M.; Livolant, M.; Epstein, A.

    1975-01-01

    In the late 1971, the CEA and FRAMATOME decided to undertake a comprehensive joint program of studying the vibration behavior of PWR internals of the 900 MWe, 50 cycle, 3 loop reactor series being built by FRAMATOME in France. The PWR reactor internals are submitted to several sources of excitation during normal operation. Two main sources of excitation may effect the internals behavior: the large flow turbulences which could generate various instabilities such as: vortex shedding: the pump pressure fluctuations which could generate acoustic noise in the circuit at frequencies corresponding to shaft speed frequencies or blade passing frequencies, and their respective harmonics. The flow induced vibrations are of complex nature and the approach selected, for this comprehensive program, is semi-empirical and based on both theoretical analysis and experiments on a reduced scale model and full scale internals. The experimental support of this program consists of: the SAFRAN test loop which consists of an hydroelastic similitude of a 1/8 scale model of a PWR; harmonic vibration tests in air performed on full scale reactor internals in the manufacturing shop; the GENNEVILLIERS facilities which is a full flow test facility of primary pump; the measurements carried out during start up on the Tihange reactor. This program will be completed in April 1975. The results of this program, the originality of which consists of studying separately the effects of random excitations and acoustic noises, on the internals behavior, and by establishing a comparison between experiments and analysis, will bring a major contribution for explaining the complex vibration phenomena occurring in a PWR

  19. INTRAVAL Finnsjoen Test - modelling results for some tracer experiments

    International Nuclear Information System (INIS)

    Jakob, A.; Hadermann, J.

    1994-09-01

    This report presents the results within Phase II of the INTRAVAL study. Migration experiments performed at the Finnsjoen test site were investigated. The study was done to gain an improved understanding of not only the mechanisms of tracer transport, but also the accuracy and limitations of the model used. The model is based on the concept of a dual porosity medium, taking into account one dimensional advection, longitudinal dispersion, sorption onto the fracture surfaces, diffusion into connected pores of the matrix rock, and sorption onto matrix surfaces. The number of independent water carrying zones, represented either as planar fractures or tubelike veins, may be greater than one, and the sorption processes are described either by linear or non-linear Freundlich isotherms assuming instantaneous sorption equilibrium. The diffusion of the tracer out of the water-carrying zones into connected pore space of the adjacent rock is calculated perpendicular to the direction of the advective/dispersive flow. In the analysis, the fluid flow parameters are calibrated by the measured breakthrough curves for the conservative tracer (iodide). Subsequent fits to the experimental data for the two sorbing tracers strontium and cesium then involve element dependent parameters providing information on the sorption processes and on its representation in the model. The methodology of fixing all parameters except those for sorption with breakthrough curves for non-sorbing tracers generally worked well. The investigation clearly demonstrates the necessity of taking into account pump flow rate variations at both boundaries. If this is not done, reliable conclusions on transport mechanisms or geometrical factors can not be achieved. A two flow path model reproduces the measured data much better than a single flow path concept. (author) figs., tabs., 26 refs

  20. 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.

  1. Modelling solute dispersion in periodic heterogeneous porous media: Model benchmarking against intermediate scale experiments

    Science.gov (United States)

    Majdalani, Samer; Guinot, Vincent; Delenne, Carole; Gebran, Hicham

    2018-06-01

    This paper is devoted to theoretical and experimental investigations of solute dispersion in heterogeneous porous media. Dispersion in heterogenous porous media has been reported to be scale-dependent, a likely indication that the proposed dispersion models are incompletely formulated. A high quality experimental data set of breakthrough curves in periodic model heterogeneous porous media is presented. In contrast with most previously published experiments, the present experiments involve numerous replicates. This allows the statistical variability of experimental data to be accounted for. Several models are benchmarked against the data set: the Fickian-based advection-dispersion, mobile-immobile, multirate, multiple region advection dispersion models, and a newly proposed transport model based on pure advection. A salient property of the latter model is that its solutions exhibit a ballistic behaviour for small times, while tending to the Fickian behaviour for large time scales. Model performance is assessed using a novel objective function accounting for the statistical variability of the experimental data set, while putting equal emphasis on both small and large time scale behaviours. Besides being as accurate as the other models, the new purely advective model has the advantages that (i) it does not exhibit the undesirable effects associated with the usual Fickian operator (namely the infinite solute front propagation speed), and (ii) it allows dispersive transport to be simulated on every heterogeneity scale using scale-independent parameters.

  2. Interpretation of experiments and modeling of internal strains in Beryllium using a polycrystal model

    International Nuclear Information System (INIS)

    Tome, C.; Bourke, M.A.M.; Daymond, M.R.

    2000-01-01

    The elastic and plastic anisotropy of Be have been examined during a uniaxial compression test, by in-situ monitoring in a pulsed neutron beam. Comparisons between the measured hkil strains and the predictions from an elasto-plastic self-consistent (EPSC) model are made. Agreement is qualitatively correct for most planes in the elasto-plastic regime. Possible mechanisms responsible for the quantitative discrepancies between model and experiment are discussed

  3. Reactive transport modeling of the ABM experiment with Comsol Multiphysics

    International Nuclear Information System (INIS)

    Pekala, Marek; Idiart, Andres; Arcos, David

    2012-01-01

    Document available in extended abstract form only. The Swedish Organisation for Radioactive Waste Disposal (SKB) is considering disposal of the High Level Waste in a deep underground repository in a crystalline rock. According to the disposal concept, bentonite clay will be used in the near-field of the waste packages as buffer material. From solute transport point of view, the bentonite buffer is expected to provide a favourable environment, where radionuclide migration would be limited to slow diffusion and further retarded by sorption. In the KBS-3 repository design, the MX-80 bentonite is the reference buffer material. However, SKB has also been investigating alternative buffer materials. To this end, the field experiment Alternative Buffer Materials (ABM) was started at the Aespoe URL in 2006. Three packages of eleven different compacted bentonite blocks in different configurations have been tested over varying time scales. The packages with outer diameter of 0.28 m were deposited into 3 meter deep boreholes. After installation, packages were saturated and heated differently to target values. This contribution concerns the evolution of Package 1, which was initiated in December 2006 and ran for about 2.5 years. Post-mortem examination after retrieval showed that the initially contrasting chloride concentrations and cation-exchanger compositions between different bentonite blocks became significantly homogenised. It is thought that this behaviour could be explained as a first approximation by diffusion of major ions between the bentonite blocks coupled with cation-exchange. In this work, a modelling study to verify this hypothesis has been undertaken. In addition, the feasibility of implementing a reactive transport model into the Finite Element code COMSOL Multiphysics has been tested. The model considers a two-dimensional axisymmetric geometry of the depositional borehole, and includes coupled diffusion and cation-exchange of Na, K, Ca and Mg (as a chloride

  4. Suggestibility and suggestive modulation of the Stroop effect.

    Science.gov (United States)

    Kirsch, Irving

    2011-06-01

    Although the induction of a hypnotic state does not seem necessary for suggestive modulation of the Stroop effect, this important phenomenon has seemed to be dependent on the subject's level of hypnotic suggestibility. Raz and Campbell's (2011) study indicates that suggestion can modulate the Stroop effect substantially in very low suggestible subjects, as well as in those who are highly suggestible. This finding casts doubt on the presumed mechanism by which suggestive modulation is brought about. Research aimed at uncovering the means by which low suggestible individuals are able to modulate the Stroop effect would be welcome, as would assessment of this effect in moderately suggestible people. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. A 10-Year Experience of Therapeutic Drug Monitoring (TDM) of Linezolid in a Hospital-wide Population of Patients Receiving Conventional Dosing: Is there Enough Evidence for Suggesting TDM in the Majority of Patients?

    Science.gov (United States)

    Pea, Federico; Cojutti, Pier Giorgio; Baraldo, Massimo

    2017-10-01

    A retrospective study was conducted to assess our 10-year experience of therapeutic drug monitoring (TDM) of linezolid in a large patient population to establish whether conventional dosing may result in adequate drug exposure in the majority of patients. Patients included in this study underwent TDM of linezolid trough concentration (C min ) during treatment with conventional doses of 600 mg every 12 hr in the period between January 2007 and June 2016. The desired range of C min was set between 2 and 7 mg/L (underexposure, C min   7 mg/L). Multivariate logistic regression analysis investigated variables potentially correlated with linezolid C min . One thousand and forty-nine patients had 2484 linezolid C min assessed during treatment with conventional doses. Median (IQR) linezolid C min was 5.08 mg/L (2.78-8.52 mg/L). Linezolid C min was within the desired range in 50.8% of cases (1262/2484). Overexposure (n = 821; 33%) occurred much more frequently than underexposure (n = 401; 16.2%) and was severe (>20 mg/L) in 3.9% of cases (98/2484). Linezolid overexposure was significantly associated with CrCL C -G estimates ≤40 mL/min. (OR 1.463; 95% CI 1.124-1.904, p = 0.005). Linezolid underexposure was significantly associated with CrCL C -G estimates >100 mL/min. (OR 3.046; 95% CI 2.234-4.152, p Linezolid C min was not correlated linearly with CrCL C -G (R 2  = 0.061). Variability in renal function explained only partially the very wide interindividual linezolid C min variability. Our study suggests that TDM could represent a valuable approach in optimizing linezolid exposure in the majority of patients. © 2017 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  6. 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.

  7. Model of lumbar spinal stenosis in the experiment

    Directory of Open Access Journals (Sweden)

    Oleg Perepechai

    2015-07-01

      Abstracts The description of an experimental model of lumbar spinal stenosis on 20 rats. The experiment was symmetrical dissection of arc plates to the inside thin cortical layer plates, and then dissection of the latter. The middle part of the arc with the spinous processes of the vertebrae is separated from the rest of the arc, and articular processes. The separated middle part of the arc with yellow ligament is shifted in the ventral direction, reducing the size of the cavity of the spinal canal and fix the contacting bone edges with bone cement. Degenerative changes of the nerve roots were evaluated histologically by endoneural and epineural changes using a 7-point scale of G. Byrond and others. In the studied group of animals 7 days after spinal canal stenosis simulations appeared degenerative changes of nerve fibers, but the degree is low, and there is virtually no endoneural inflammation. The epineurium determined expressed or gross changes, indicating epineural inflammatory processes. After 1 month. There appeared dystrophic and degenerative changes of nerve fibers of the overwhelming majority (over 75%. At a later date (3 months, endoneural change remained practically the same as in the 1th month after surgery, epineural violations were preserved, there were groups and single fibroblasts as a sign of epineural fibrosis, as well as portions of connective tissue neoplasms and hyalinosis.   Keywords: lumbar spinal stenosis, an experimental model.

  8. Modelling the fathering role: Experience in the family of origin and father involvement

    Directory of Open Access Journals (Sweden)

    Mihić Ivana

    2012-01-01

    Full Text Available The study presented in this paper deals with the effects of experiences with father in the family of origin on the fathering role in the family of procreation. The results of the studies so far point to great importance of such experiences in parental role modelling, while recent approaches have suggested the concept of introjected notion or an internal working model of the fathering role as the way to operationalise the transgenerational transfer. The study included 247 two-parent couple families whose oldest child attended preschool education. Fathers provided information on self-assessed involvement via the Inventory of father involvement, while both fathers and mothers gave information on introjected experiences from the family of origin via the inventory Presence of the father in the family of origin. It was shown that father’s experiences from the family of origin had significant direct effects on his involvement in child-care. Very important experiences were those of negative emotional exchange, physical closeness and availability of the father, as well as beliefs about the importance of the father as a parent. Although maternal experiences from the family of origin did not contribute significantly to father involvement, shared beliefs about father’s importance as a parent in the parenting alliance had an effect on greater involvement in child-care. The data provide confirmation of the hypotheses on modelling of the fathering role, but also open the issue of the factor of intergenerational maintenance of traditional forms of father involvement in families in Serbia.

  9. Suggestibility and negative priming: two replication studies.

    Science.gov (United States)

    David, Daniel; Brown, Richard J

    2002-07-01

    Research suggests that inhibiting the effect of irrelevant stimuli on subsequent thought and action (cognitive inhibition) may be an important component of suggestibility. Two small correlation studies were conducted to address the relationship between different aspects of suggestibility and individual differences in cognitive inhibition, operationalized as the degree of negative priming generated by to-be-ignored stimuli in a semantic categorization task. The first study found significant positive correlations between negative priming, hypnotic suggestibility, and creative imagination; a significant negative correlation was obtained between negative priming and interrogative suggestibility, demonstrating the discriminant validity of the study results. The second study replicated the correlation between negative priming and hypnotic suggestibility, using a different suggestibility measurement procedure that assessed subjective experience and hypnotic involuntariness as well as objective responses to suggestions. These studies support the notion that the ability to engage in cognitive inhibition may be an important component of hypnotic responsivity and maybe of other forms of suggestibility.

  10. Dislocation-free zone model of fracture comparison with experiments

    International Nuclear Information System (INIS)

    Ohr, S.M.; Chang, S.

    1982-01-01

    The dislocation-free zone (DFZ) model of fracture has been extended to study the relationship between the stress intensity factor, extent of plastic deformation, and crack tip geometry of an elastic-plastic crack as a function of applied stress. The results show that the stress intensity factor K decreases from the elastic value at first slowly, then goes rapidly to zero as the number of dislocations in the plastic zone increases. The crack with a zero stress intensity factor has its crack tip stress field completely relaxed by plastic deformation and hence is called a plastic crack. Between the elastic and plastic cracks, a wide range of elastic-plastic cracks having both a stress singularity and a plastic zone are possible. These elastic-plastic cracks with a DFZ are predicted if there is a critical stress intensity factor K/sub g/ required for the generation of dislocations at the crack tip. The expression for K/sub g/ is obtained from the crack tip dislocation nucleation model of Rice and Thomson. In most metals, the magnitude of K/sub g/ is less than the critical stress intensity factor for brittle fracture K/sub c/. The values of K are determined from electron microscope fracture experiments for various metals and they are found to be in good agreement with the K/sub g/ predicted from the model. It is concluded that for most ductile and semibrittle metals, the mechanism of dislocation generation is more important than the fracture surface energy in determining the stress intensity factor at the crack tip

  11. Thermal hydraulic test for reactor safety system - Critical heat flux experiment and development of prediction models

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Soon Heung; Baek, Won Pil; Yang, Soo Hyung; No, Chang Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea)

    2000-04-01

    To acquire CHF data through the experiments and develop prediction models, research was conducted. Final objectives of research are as follows: 1) Production of tube CHF data for low and middle pressure and mass flux and Flow Boiling Visualization. 2) Modification and suggestion of tube CHF prediction models. 3) Development of fuel bundle CHF prediction methodology base on tube CHF prediction models. The major results of research are as follows: 1) Production of the CHF data for low and middle pressure and mass flux. - Acquisition of CHF data (764) for low and middle pressure and flow conditions - Analysis of CHF trends based on the CHF data - Assessment of existing CHF prediction methods with the CHF data 2) Modification and suggestion of tube CHF prediction models. - Development of a unified CHF model applicable for a wide parametric range - Development of a threshold length correlation - Improvement of CHF look-up table using the threshold length correlation 3) Development of fuel bundle CHF prediction methodology base on tube CHF prediction models. - Development of bundle CHF prediction methodology using correction factor. 11 refs., 134 figs., 25 tabs. (Author)

  12. 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...

  13. 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

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

    International Nuclear Information System (INIS)

    Hoyer, Michael

    2017-01-01

    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.

  15. 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.

  16. Data from the Hot Serial Cereal Experiment for modeling wheat response to temperature: field experiments and AgMIP-Wheat multi-model simulations

    NARCIS (Netherlands)

    Martre, Pierre; Kimball, Bruce A.; Ottman, Michael J.; Wall, Gerard W.; White, Jeffrey W.; Asseng, Senthold; Ewert, Frank; Cammarano, Davide; Maiorano, Andrea; Aggarwal, Pramod K.; Supit, I.; Wolf, J.

    2018-01-01

    The dataset 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

  17. 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)

  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. Experiments with a Regional Vector-Vorticity Model, and Comparison with Other Models

    Science.gov (United States)

    Konor, C. S.; Dazlich, D. A.; Jung, J.; Randall, D. A.

    2017-12-01

    The Vector-Vorticity Model (VVM) is an anelastic model with a unique dynamical core that predicts the three-dimensional vorticity instead of the three-dimensional momentum. The VVM is used in the CRMs of the Global Quasi-3D Multiscale Modeling Framework, which is discussed by Joon-Hee Jung and collaborators elsewhere in this session. We are updating the physics package of the VVM, replacing it with the physics package of the System for Atmosphere Modeling (SAM). The new physics package includes a double-moment microphysics, Mellor-Yamada turbulence, Monin-Obukov surface fluxes, and the RRTMG radiation parameterization. We briefly describe the VVM and show results from standard test cases, including TWP-ICE. We compare the results with those obtained using the earlier physics. We also show results from experiments on convection aggregation in radiative-convective equilibrium, and compare with those obtained using both SAM and the Regional Atmospheric Modeling System (RAMS).

  20. 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....

  1. A Model for Designing Adaptive Laboratory Evolution Experiments

    DEFF Research Database (Denmark)

    LaCroix, Ryan A.; Palsson, Bernhard O.; Feist, Adam M.

    2017-01-01

    in suboptimal experiments that can take multiple months to complete. With the availability of automation and computer simulations, we can now perform these experiments in an optimized fashion and can design experiments to generate greater fitness in an accelerated time frame, thereby pushing the limits of what...

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. Modelling and experiments on NTM stabilisation at ASDEX upgrade

    International Nuclear Information System (INIS)

    Urso, Laura

    2009-01-01

    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

  9. Structural Adjustment Policy Experiments: The Use of Philippine CGE Models

    OpenAIRE

    Cororaton, Caesar B.

    1994-01-01

    This paper reviews the general structure of the following general computable general equilibrium (CGE): the APEX model, Habito’s second version of the PhilCGE model, Cororaton’s CGE model and Bautista’s first CGE model. These models are chosen as they represent the range of recently constructed CGE models of the Philippine economy. They also represent two schools of thought in CGE modeling: the well defined neoclassical, Walrasian, general equilibrium school where the market-clearing variable...

  10. Grazing experiments and model simulations of the role of zooplankton in Phaeocystis food webs

    Science.gov (United States)

    Verity, P. G.

    2000-08-01

    A combined empirical and modelling study was conducted to further examine the potential importance of grazing by zooplankton in pelagic food webs in which Phaeocystis is a significant or dominant component. Laboratory experiments were designed to measure ingestion of Phaeocystis and other potential prey items which co-occur with Phaeocystis. Grazers included copepods and ciliates, and prey included Phaeocystis colonies and solitary cells, diatoms, ciliates, bacteria, and detritus. These data were expressed in the model currency of nitrogen units, and fit to hyperbolic tangent equations which included minimum prey thresholds. These equations and literature data were used to constrain a food web model whose purpose was to investigate trophic interactions rather than to mimic actual events. Nevertheless, the model output was similar to the general pattern and magnitude of development of Phaeocystis-diatom communities in some environments where they occur, e.g. north Norwegian waters. The model included three forms of nitrogen, three phytoplankton groups, bacteria, two zooplankton groups, and detritus, with detailed flows between compartments. An important component of the model was inclusion of variable prey preferences for zooplankton. The experiments and model simulations suggest several salient conclusions. Phaeocystis globosa colonies were eaten by a medium-sized copepod species, but ingestion appeared to be strongly dependent upon a proper size match between grazer and prey. If not, colonies were eaten little if at all. Phaeocystis solitary cells were ingested rapidly by ciliate microzooplankton, in agreement with prior literature observations. In contrast, detritus was eaten comparatively slowly by both ciliates and copepods. Both types of zooplankton exhibited apparent minimum prey thresholds below which grazing did not occur or was inconsequential. Model simulations implied that transitions between life cycle stages of Phaeocystis may potentially be important

  11. 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.

  12. 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

  13. 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.

  14. Experiments in Error Propagation within Hierarchal Combat Models

    Science.gov (United States)

    2015-09-01

    stochastic Lanchester campaign model that contains 18 Blue and 25 Red submarines. The outputs of the campaign models are analyzed statistically. The...sampled in a variety of ways, including just the mean, and used to calculate the attrition coefficients for a stochastic Lanchester campaign model...9 2. Lanchester Models .............................................................................10 III. SCENARIO AND MODEL DEVELOPMENT

  15. 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

  16. 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.

  17. 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

  18. The VLAB OER Experience: Modeling Potential-Adopter Student Acceptance

    Science.gov (United States)

    Raman, Raghu; Achuthan, Krishnashree; Nedungadi, Prema; Diwakar, Shyam; Bose, Ranjan

    2014-01-01

    Virtual Labs (VLAB) is a multi-institutional Open Educational Resources (OER) initiative, exclusively focused on lab experiments for engineering education. This project envisages building a large OER repository, containing over 1650 virtual experiments mapped to the engineering curriculum. The introduction of VLAB is a paradigm shift in an…

  19. Verification of MC{sup 2}-3 Doppler Sample Models in ZPPR-15 D Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Jae; Hartanto, Donny; Kim, Sang Ji [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    In this paper, the change of reaction rate and broadened cross section were estimated by as-built MCNP models for metallic uranium sample in ZPPR-15D using ENDF/B-VII.0 library, and the results were compared with deterministic calculations provided in previous work. The Doppler broadening is an instant feedback mechanism that improves safety and stability for both thermal and fast reactors. Therefore, the accuracy of Doppler coefficient becomes an important parameter in reactor design as well as in the safety analysis. The capability of the Doppler worth calculation by a modern computer code suites such as MC2-3 and DIF3DVARIANT, has been validated against the Zero Power Physics Reactor-15 (ZPPR-15) Doppler worth measurement experiments. For the same experiments, our previous work suggested four different MC2-3 Doppler sample models for enhanced accuracy, which are combinations of heterogeneous models and the super cell approach. The MOC and MOC-SPC models showed the smallest error in estimating the U-238 total cross section of Doppler sample N-11, and the Doppler broadening effects are well applied to the cross section compared to other two models, HOM and SPC. The effects of the super cell approach can be hardly seen, since the broadened cross section is almost the same with and without the super cell approach. Comparing the transition of reaction density, MOC and MOC-SPC models also show similar behavior as MCNP's with minor errors. As a conclusion, we could obtain more consistent broadened cross section as well as reaction density transition by providing heterogeneous models from MC2-3's MOC module.

  20. Calibrating vadose zone models with time-lapse gravity data: a forced infiltration experiment

    DEFF Research Database (Denmark)

    Christiansen, Lars; Hansen, Allan Bo; Zibar, Majken Caroline Looms

    A change in soil water content is a change in mass stored in the subsurface, and when large enough, can be measured with a gravity meter. Over the last few decades there has been increased use of ground-based time-lapse gravity measurements to infer hydrogeological parameters. These studies have...... focused on the saturated zone, with specific yield as the most prominent target parameter and with few exceptions, changes in storage in the vadose zone have been considered as noise. Here modeling results are presented suggesting that gravity changes will be measureable when soil moisture changes occur...... in the unsaturated zone. These results are confirmed by field measurements of gravity and georadar data at a forced infiltration experiment conducted over 14 days on a grassland area of 10 m by 10 m. An unsaturated zone infiltration model can be calibrated using the gravity data with good agreement to the field data...

  1. Synchronization Experiments With A Global Coupled Model of Intermediate Complexity

    Science.gov (United States)

    Selten, Frank; Hiemstra, Paul; Shen, Mao-Lin

    2013-04-01

    In the super modeling approach an ensemble of imperfect models are connected through nudging terms that nudge the solution of each model to the solution of all other models in the ensemble. The goal is to obtain a synchronized state through a proper choice of connection strengths that closely tracks the trajectory of the true system. For the super modeling approach to be successful, the connections should be dense and strong enough for synchronization to occur. In this study we analyze the behavior of an ensemble of connected global atmosphere-ocean models of intermediate complexity. All atmosphere models are connected to the same ocean model through the surface fluxes of heat, water and momentum, the ocean is integrated using weighted averaged surface fluxes. In particular we analyze the degree of synchronization between the atmosphere models and the characteristics of the ensemble mean solution. The results are interpreted using a low order atmosphere-ocean toy model.

  2. 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.

  3. 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

  4. Model complexity in carbon sequestration:A design of experiment and response surface uncertainty analysis

    Science.gov (United States)

    Zhang, Y.; Li, S.

    2014-12-01

    Geologic carbon sequestration (GCS) is proposed for the Nugget Sandstone in Moxa Arch, a regional saline aquifer with a large storage potential. For a proposed storage site, this study builds a suite of increasingly complex conceptual "geologic" model families, using subsets of the site characterization data: a homogeneous model family, a stationary petrophysical model family, a stationary facies model family with sub-facies petrophysical variability, and a non-stationary facies model family (with sub-facies variability) conditioned to soft data. These families, representing alternative conceptual site models built with increasing data, were simulated with the same CO2 injection test (50 years at 1/10 Mt per year), followed by 2950 years of monitoring. Using the Design of Experiment, an efficient sensitivity analysis (SA) is conducted for all families, systematically varying uncertain input parameters. Results are compared among the families to identify parameters that have 1st order impact on predicting the CO2 storage ratio (SR) at both end of injection and end of monitoring. At this site, geologic modeling factors do not significantly influence the short-term prediction of the storage ratio, although they become important over monitoring time, but only for those families where such factors are accounted for. Based on the SA, a response surface analysis is conducted to generate prediction envelopes of the storage ratio, which are compared among the families at both times. Results suggest a large uncertainty in the predicted storage ratio given the uncertainties in model parameters and modeling choices: SR varies from 5-60% (end of injection) to 18-100% (end of monitoring), although its variation among the model families is relatively minor. Moreover, long-term leakage risk is considered small at the proposed site. In the lowest-SR scenarios, all families predict gravity-stable supercritical CO2 migrating toward the bottom of the aquifer. In the highest

  5. 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.

  6. Sediment fingerprinting experiments to test the sensitivity of multivariate mixing models

    Science.gov (United States)

    Gaspar, Leticia; Blake, Will; Smith, Hugh; Navas, Ana

    2014-05-01

    fluvial sorting of the resulting mixture took place. Most particle size correction procedures assume grain size affects are consistent across sources and tracer properties which is not always the case. Consequently, the < 40 µm fraction of selected soil mixtures was analysed to simulate the effect of selective fluvial transport of finer particles and the results were compared to those for source materials. Preliminary findings from this experiment demonstrate the sensitivity of the numerical mixing model outputs to different particle size distributions of source material and the variable impact of fluvial sorting on end member signatures used in mixing models. The results suggest that particle size correction procedures require careful scrutiny in the context of variable source characteristics.

  7. 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;

  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_2Te_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. Experiment selection for the discrimination of semi-quantitative models of dynamical systems

    NARCIS (Netherlands)

    Vatcheva, [No Value; de Jong, H; Bernard, O; Mars, NJI

    Modeling an experimental system often results in a number of alternative models that are all justified by the available experimental data. To discriminate among these models, additional experiments are needed. Existing methods for the selection of discriminatory experiments in statistics and in

  10. Interrogative suggestibility in opiate users.

    Science.gov (United States)

    Murakami, A; Edelmann, R J; Davis, P E

    1996-09-01

    The present study investigated interrogative suggestibility in opiate users. A group of patients undergoing a methadone detoxification programme in an in-patient drug treatment unit (Detox group, n = 21), and a group of residents who had come off drugs and were no longer suffering from withdrawal syndrome (Rehab group, n = 19) were compared on interrogative suggestibility and various other psychological factors. Significant differences were found between the two groups, with the Detox group having more physical and psychological problems, and a higher total suggestibility score in comparison with the Rehab group. These findings are discussed in relation to the context of police interrogations and the reliability of confessions made by suspects and witnesses dependent on opiates.

  11. 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......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...

  12. 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

  13. 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, their va...

  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. 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

  16. 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

  17. 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…

  18. Modelling ohmic confinement experiments on the START tokamak

    International Nuclear Information System (INIS)

    Roach, C.M.

    1996-05-01

    Ohmic confinement data from the tight aspect ratio tokamak START has been analysed using the ASTRA transport simulation code. Neoclassical expressions have been modified to describe tight aspect ratio configurations, and the comparison between START data and models of anomalous transport has been made quantitative using the standard χ 2 test from statistics. Four confinement models (T11, Rebut-Lallia-Watkins, Lackner-Gottardi, and Taroni et al's Bohm model) have been compared with the START data. Three of the models are found to simulate START's electron temperature data moderately well, while Taroni et al's Bohm model overestimates electron temperatures in START by an order of magnitude. Thus comparison with START data tends to discriminate against Bohm models; these models are pessimistic or ITER. (author)

  19. The suggestion about the absence of the phase transition, vacuum degeneration, spontaneous symmetry breaking and zero-mass Goldstone-bosons in QFT models of the type gphi4

    International Nuclear Information System (INIS)

    Zastavenko, L.G.

    1979-01-01

    The usual proof of the phase transition existence in the gphi 4 model is considered. (For M 2 >M 0 2 minimum of the effective potential is at phi(0)=0, for M 2 >M 0 2 this minimum is at phi(0)=+-lambda not equal to 0, lambda→+ infinity at M 2 →- infinity). This proof is shown to be wrong, thus suggesting the absence in the model considered of the phase transition, vacuum degeneration, spontaneous symmetry breaking and zero-mass Goldstone-bosons

  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. 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

  2. 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

  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. 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...

  5. A Feedback Model for Data-Rich Learning Experiences

    Science.gov (United States)

    Pardo, Abelardo

    2018-01-01

    Feedback has been identified as one of the factors with the largest potential for a positive impact in a learning experience. There is a significant body of knowledge studying feedback and providing guidelines for its implementation in learning environments. In parallel, the areas of learning analytics or educational data mining have emerged to…

  6. Modeling and experiment to threshing unit of stripper combine

    African Journals Online (AJOL)

    User

    2011-05-16

    May 16, 2011 ... L was the free grain which had reached the end of the threshing unit but still not separated. On the designed testing equipment, experiments of threshing performances were conducted with the different feed rates and drum rotator speeds for the rice stripped mixtures. Experimental results showed that the ...

  7. 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…

  8. 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

  9. Left ventricular shear strain in model and experiment

    NARCIS (Netherlands)

    Ubbink, S.; Bovendeerd, P.H.M.; Delhaas, T.; Arts, M.G.J.; Vosse, van de F.N.

    2005-01-01

    Mathematical modeling of cardiac mechanics could be a useful clinical tool, both in translating measured abnormalities in cardiac deformation into the underlying pathology, and in selecting a propertreatment. We investigated to what extent a previously published model of cardiac mechanics could

  10. 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...

  11. 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

  12. Experiences with testing PCRV concrete and epoxy resin models

    International Nuclear Information System (INIS)

    Schimmelpfennig, K.; Schnellenbach, G.

    1979-01-01

    A 1:5 scale model of a prestressed concrete pressure vessel was used to investigate its operating behaviour when only partially prestressed so as to allow cracking even under operating conditions. Further experimental work consisted in the building and testing of epoxy resin models to check the results of three-dimensional numerical calculations. Results show that a partially prestressed vessel will operate reliably and that deformations under both short and long-term internal pressure are essentially reversible. The results from the epoxy resin models show that building such models also with complicated geometries and with embedded strain gauges can be successfully carried out and that testing such models is a good tool for checking computer calculations

  13. 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

  14. Responding to hypnotic and nonhypnotic suggestions: performance standards, imaginative suggestibility, and response expectancies.

    Science.gov (United States)

    Meyer, Eric C; Lynn, Steven Jay

    2011-07-01

    This study examined the relative impact of hypnotic inductions and several other variables on hypnotic and nonhypnotic responsiveness to imaginative suggestions. The authors examined how imaginative suggestibility, response expectancies, motivation to respond to suggestions, and hypnotist-induced performance standards affected participants' responses to both hypnotic and nonhypnotic suggestions and their suggestion-related experiences. Suggestions were administered to 5 groups of participants using a test-retest design: (a) stringent performance standards; (b) lenient performance standards; (c) hypnosis test-retest; (d) no-hypnosis test-retest; and (e) no-hypnosis/hypnosis control. The authors found no support for the influence of a hypnotic induction or performance standards on responding to suggestions but found considerable support for the role of imaginative suggestibility and response expectancies in predicting responses to both hypnotic and nonhypnotic suggestions.

  15. Suggestibility, Dissociation and Positive Schizotypy

    Directory of Open Access Journals (Sweden)

    Emma Barkus

    2010-01-01

    Full Text Available Partimos de una muestra de 94 participantes, seleccionados de la muestra de referencia de 1206 personas que ya habían participado en un estudio que valoraba la estructura factorial del Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE. Estas 94 personas fueron asignadas en grupos diferenciados en términos de bajo, moderado o altos niveles de esquizotipia positiva. Todos completaron también la Escala de Experiencias Disociativas (DES y el Inventario de Sugestionabilidad (IOS. Nuestros resultados sugieren que el aumento de los niveles informados de las experiencias disociativas y mayor sugestionabilidad, ambos, de forma independiente, predicen puntuaciones más altas de la esquizotipia positiva, pero la sugestión parece ser un predictor más potente que la disociación.

  16. 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.

  17. 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.

  18. Coalescence of liquid drops: Different models versus experiment

    KAUST Repository

    Sprittles, J. E.; Shikhmurzaev, Y. D.

    2012-01-01

    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

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

    Indian Academy of Sciences (India)

    the models and monitoring the improvements in gravity field recovery are required. This study assesses ... group from the Inter- national Gravity Field Service (IGFS) and the ..... the method, the process may therefore be iter- ated until the ...

  20. 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.

  1. 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...

  2. Event-based computer simulation model of aspect-type experiments strictly satisfying Einstein's locality conditions

    NARCIS (Netherlands)

    De Raedt, Hans; De Raedt, Koen; Michielsen, Kristel; Keimpema, Koenraad; Miyashita, Seiji

    2007-01-01

    Inspired by Einstein-Podolsky-Rosen-Bohtn experiments with photons, we construct an event-based simulation model in which every essential element in the ideal experiment has a counterpart. The model satisfies Einstein's criterion of local causality and does not rely on concepts of quantum and

  3. A business process modeling experience in a complex information system re-engineering.

    Science.gov (United States)

    Bernonville, Stéphanie; Vantourout, Corinne; Fendeler, Geneviève; Beuscart, Régis

    2013-01-01

    This article aims to share a business process modeling experience in a re-engineering project of a medical records department in a 2,965-bed hospital. It presents the modeling strategy, an extract of the results and the feedback experience.

  4. Dynamic-chemistry-aerosol modelling interaction: the ESCOMPTE 2001 experiment

    International Nuclear Information System (INIS)

    Cousin, F.

    2004-09-01

    After most pollution studies independently devoted to gases and aerosols, there now appears an urgent need to consider their interactions. In this view, an aerosol module has been implemented in the Meso-NH-C model to simulate two IOPs documented during the ESCOMPTE campaign which took place in the Marseille/Fos-Berre region in June-July 2001. First, modelled dynamic parameters (winds, temperatures, boundary layer thickness) and gaseous chemistry have been validated with measurements issued from the exhaustive ESCOMPTE database. Sensitivity analysis have also been performed using different gaseous emission inventories at various resolution. These simulations have illustrated the deep impact of both synoptic and local dynamics on observed ozone concentrations on June 24 (IOP2b) in the ESCOMPTE domain. Afterwards, the ORISAM aerosol module has been introduced into the Meso-NH-C model. Dynamics, gaseous chemistry and aerosol processes have thus been coupled on-line. The particulate pollution episode on June 24 (IOP2b) has been characterised through a satisfactory comparison, specially from sub-micron particles, between modelling and measurements at different representative stations in the domain. This study, with validation of the particulate emission inventory has also highlighted the need for future improvements, such as further characterisation of organic and inorganic aerosol species and consideration of coarse particles. Aerosol impact on gaseous chemistry has been preliminary approached in view of future development and modification to be given to the Meso-NH-C model. (author)

  5. Integrated predictive modelling simulations of burning plasma experiment designs

    International Nuclear Information System (INIS)

    Bateman, Glenn; Onjun, Thawatchai; Kritz, Arnold H

    2003-01-01

    Models for the height of the pedestal at the edge of H-mode plasmas (Onjun T et al 2002 Phys. Plasmas 9 5018) are used together with the Multi-Mode core transport model (Bateman G et al 1998 Phys. Plasmas 5 1793) in the BALDUR integrated predictive modelling code to predict the performance of the ITER (Aymar A et al 2002 Plasma Phys. Control. Fusion 44 519), FIRE (Meade D M et al 2001 Fusion Technol. 39 336), and IGNITOR (Coppi B et al 2001 Nucl. Fusion 41 1253) fusion reactor designs. The simulation protocol used in this paper is tested by comparing predicted temperature and density profiles against experimental data from 33 H-mode discharges in the JET (Rebut P H et al 1985 Nucl. Fusion 25 1011) and DIII-D (Luxon J L et al 1985 Fusion Technol. 8 441) tokamaks. The sensitivities of the predictions are evaluated for the burning plasma experimental designs by using variations of the pedestal temperature model that are one standard deviation above and below the standard model. Simulations of the fusion reactor designs are carried out for scans in which the plasma density and auxiliary heating power are varied

  6. Supercritical extraction of carqueja essential oil: experiments and modeling

    Directory of Open Access Journals (Sweden)

    R. M. F. Vargas

    2006-09-01

    Full Text Available Baccharis trimera is a native Brazilian plant which has medicinal properties. In this work a method of supercritical extraction was studied to obtain the popularly essential oil from Baccharis trimera, known as carqueja. The aim was to obtain experimental data and to compare two mathematical models used in the simulation of carqueja (Baccharis trimera oil extraction by supercritical CO2. The two mathematical models are based on mass transfer. One of the models, proposed by Reverchon, is solved numerically and requires two adjustable parameters from the experimental data. The other model chosen is the one proposed by Sovová. This model is solved analytically and requires four adjustable parameters. Numerical results are presented and discussed for the adjusted parameters. The experimental results are obtained in a temperature range of 313.15 K to 343.15 K at 90 bar. The extraction yield of carqueja essential oil using supercritical carbon dioxide ranged between 1.72 % (w/w at 323.15 K and 2.34 % (w/w at 343.15 K, 90 bar with a CO2 flow rate of 3.34.10-8 m³/s for a 0.0015 kg sample of Baccharis trimera.

  7. 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

  8. Discrimination of Semi-Quantitative Models by Experiment Selection: Method Application in Population Biology

    NARCIS (Netherlands)

    Vatcheva, Ivayla; Bernard, Olivier; de Jong, Hidde; Gouze, Jean-Luc; Mars, Nicolaas; Nebel, B.

    2001-01-01

    Modeling an experimental system often results in a number of alternative models that are justified equally well by the experimental data. In order to discriminate between these models, additional experiments are needed. We present a method for the discrimination of models in the form of

  9. Interim Service ISDN Satellite (ISIS) network model for advanced satellite designs and experiments

    Science.gov (United States)

    Pepin, Gerard R.; Hager, E. Paul

    1991-01-01

    The Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) Network Model for Advanced Satellite Designs and Experiments describes a model suitable for discrete event simulations. A top-down model design uses the Advanced Communications Technology Satellite (ACTS) as its basis. The ISDN modeling abstractions are added to permit the determination and performance for the NASA Satellite Communications Research (SCAR) Program.

  10. Period adding cascades: experiment and modeling in air bubbling.

    Science.gov (United States)

    Pereira, Felipe Augusto Cardoso; Colli, Eduardo; Sartorelli, José Carlos

    2012-03-01

    Period adding cascades have been observed experimentally/numerically in the dynamics of neurons and pancreatic cells, lasers, electric circuits, chemical reactions, oceanic internal waves, and also in air bubbling. We show that the period adding cascades appearing in bubbling from a nozzle submerged in a viscous liquid can be reproduced by a simple model, based on some hydrodynamical principles, dealing with the time evolution of two variables, bubble position and pressure of the air chamber, through a system of differential equations with a rule of detachment based on force balance. The model further reduces to an iterating one-dimensional map giving the pressures at the detachments, where time between bubbles come out as an observable of the dynamics. The model has not only good agreement with experimental data, but is also able to predict the influence of the main parameters involved, like the length of the hose connecting the air supplier with the needle, the needle radius and the needle length.

  11. 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.)

  12. 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.

  13. 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

  14. 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...

  15. A review of experiments testing the shoving model

    DEFF Research Database (Denmark)

    Hecksher, Tina; Dyre, J. C.

    2015-01-01

    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...... 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...

  16. 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....

  17. Scanning tunneling spectroscopy on organic semiconductors : experiment and model

    NARCIS (Netherlands)

    Kemerink, M.; Alvarado, S.F.; Müller, P.; Koenraad, P.M.; Salemink, H.W.M.; Wolter, J.H.; Janssen, R.A.J.

    2004-01-01

    Scanning-tunneling spectroscopy expts. performed on conjugated polymer films are compared with three-dimensional numerical model calcns. for charge injection and transport. It is found that if a sufficiently sharp tip is used, the field enhancement near the tip apex leads to a significant increase

  18. 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…

  19. 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

  20. 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

  1. 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.

  2. 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...

  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. Quark model and high-energy nuclear experiments

    International Nuclear Information System (INIS)

    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

  5. 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)

  6. 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

    2017-01-01

    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 them. Aim: To assess national models and methods for financing and reimbursing palliative care. Design: 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. Results: 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. Conclusion: 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. PMID:28156188

  7. 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.

  8. Modeling of ICRH experiments in the Tara tandem mirror

    International Nuclear Information System (INIS)

    Myer, R.C.; Golovato, S.N.

    1987-01-01

    The production and heating of the central cell plasma in Tara is provided by a slot antenna located on the midplane bump of the axial magnetic field profile. Slow ion cyclotron waves excited by the slot propagate down a magnetic beach to ion cyclotron resonance layers located on either side of the bump where the RF power is strongly damped by the ions. Two different theoretical models are being used to study the efficiency of coupling to slow waves in this configuration. Wave propagation models which are based on the infinite plasma dispersion relation for a cold plasma indicate that radially propagating left hand polarized slow waves are converted to right hand polarized fast waves at the Alfven resonance layer due to the radial density gradient. If this were to occur we would expect a lower coupling efficiency to the ions in the plasma core. On the other hand, a nonlocal kinetic model of RF wave propagation in a nonuniform plasma slab indicates that significant left hand component of the electric field extends beyond the Alfven resonance layer. Preliminary experimental measurements of the radial inductive field profile agree qualitatively with the predictions of the cold plasma model, however, there is insufficient data at this time time to establish that a density limit for slow wave accessibility to the plasma core exists

  9. Modeling of ICRH experiments in the Tara tandem mirror

    International Nuclear Information System (INIS)

    Myer, R.C.; Golovato, S.N.

    1987-05-01

    The production and heating of the central cell plasma in Tara are provided by a slot antenna located on the midplane bump of the axial magnetic field profile. Slow ion cyclotron waves excited by the slot propagate down a magnetic beach to ion cyclotron resonance layers located on either side of the bump where the rf power is strongly damped by the ions. Two different theoretical models are being used to study the efficiency of coupling to slow waves in this configuration. Wave propagation models which are based on the infinite plasma dispersion relation for a cold plasma indicate that radially propagating left hand polarized slow waves are converted to right hand polarized fast waves at the Alfven resonance layer due to the radial density gradient. If this were to occur we would expect a lower coupling efficiency to the ions in the plasma core. On the other hand, a nonlocal kinetic model of rf wave propagation in a nonuniform plasma slab indicates that a significant left hand component of the electric field extends beyond the Alfven resonance layer. Preliminary experimental measurements of the radial inductive field profile agree qualitatively with the predictions of the cold plasma model, however, there is insufficient data at this time to establish that a density limit for slow wave accessibility to the plasma core exists

  10. 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

  11. 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

  12. 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)

  13. Modelling Drug Administration Regimes for Asthma: A Romanian Experience

    Science.gov (United States)

    Andras, Szilard; Szilagyi, Judit

    2010-01-01

    In this article, we present a modelling activity, which was a part of the project DQME II (Developing Quality in Mathematics Education, for more details see http://www.dqime.uni-dortmund.de) and some general observations regarding the maladjustments and rational errors arising in such type of activities.

  14. 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.

  15. Numerical modeling of centrifuge cyclic lateral pile load experiments

    Science.gov (United States)

    Gerolymos, Nikos; Escoffier, Sandra; Gazetas, George; Garnier, Jacques

    2009-03-01

    To gain insight into the inelastic behavior of piles, the response of a vertical pile embedded in dry sand and subjected to cyclic lateral loading was studied experimentally in centrifuge tests conducted in Laboratoire Central des Ponts et Chaussées. Three types of cyclic loading were applied, two asymmetric and one symmetric with respect to the unloaded pile. An approximately square-root variation of soil stiffness with depth was obtained from indirect in-flight density measurements, laboratory tests on reconstituted samples, and well-established empirical correlations. The tests were simulated using a cyclic nonlinear Winkler spring model, which describes the full range of inelastic phenomena, including separation and re-attachment of the pile from and to the soil. The model consists of three mathematical expressions capable of reproducing a wide variety of monotonic and cyclic experimental p-y curves. The physical meaning of key model parameters is graphically explained and related to soil behavior. Comparisons with the centrifuge test results demonstrate the general validity of the model and its ability to capture several features of pile-soil interaction, including: soil plastification at an early stage of loading, “pinching” behavior due to the formation of a relaxation zone around the upper part of the pile, and stiffness and strength changes due to cyclic loading. A comparison of the p-y curves derived from the test results and the proposed model, as well as those from the classical curves of Reese et al. (1974) for sand, is also presented.

  16. Model experiments for {sup 14}C water-age determinations

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, I; Stahl, W; Geyh, M; Fauth, F [Bundesanstalt fuer Bodenforschung, Hannover (Germany)

    1967-05-15

    The {sup 14}C age of water samples is calculated by assuming that fossil carbonate is dissolved by biogenic CO{sub 2} according to the equation x{sub 1} {center_dot} CaCO{sub 3} + (x{sub 1}+y{sub 1}) {center_dot} CO{sub 2} + H{sub 2}O = 2x{sub 1} {center_dot} HCO{sub 3} + y{sub 1} {center_dot} CO{sub 2} where x and y are the number of moles of the two carbon components before and after the dissolution process. In a closed system the relation y{sub 1} = K(T) (x{sub 1}){sup 3} must be satisfied additionally. The equilibrium constant K(T), which depends on the temperature, controls the concentrations of free CO{sub 2} and HCO{sub 3}. To investigate the mechanism of the dissolution, laboratory experiments under controlled conditions were carried out. Non-radioactive CaCO{sub 3}, which had a {delta}{sup 13}C-value of +30 per mille, and radioactive CO{sub 2} with {delta}{sup 13}C = -22 per mille were used. The purpose of these investigations was to check the validity of theoretical assumptions regarding the average {sup 14}C-activity and the {delta}{sup 13}C-value of the total carbon which is dissolved as CO{sub 2} and HCO{sub 3}. Furthermore, it was investigated whether, within the duration of the experiment, a possible exchange takes place between the undissolved carbon present in the CaCO{sub 3} and that present in the HCO{sub 3}. The importance of this lies in the fact that the method of {sup 14}C age determination is based on the assumption that such an exchange does not take place. The experiments which have been performed up to now show that in case of the simple CaCO{sub 3} - CO{sub 2} system, which has been considered first, this assumption is not justified even for a constant water temperature. If variations in the water temperature occur during the history of the water sample, precipitation and redissolution processes influence the {sup 14}C- and {delta}{sup 13}C -values differently. This is due to isotopic fractionation processes between the HCO{sub 3} and CO

  17. 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 ...

  18. 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.

  19. 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)

  20. Testing increases suggestibility for narrative-based misinformation but reduces suggestibility for question-based misinformation.

    Science.gov (United States)

    LaPaglia, Jessica A; Chan, Jason C K

    2013-01-01

    A number of recent studies have found that recalling details of an event following its occurrence can increase people's suggestibility to later presented misinformation. However, several other studies have reported the opposite result, whereby earlier retrieval can reduce subsequent eyewitness suggestibility. In the present study, we investigated whether differences in the way misinformation is presented can modulate the effects of testing on suggestibility. Participants watched a video of a robbery and some were questioned about the event immediately afterwards. Later, participants were exposed to misinformation in a narrative (Experiment 1) or in questions (Experiment 2). Consistent with previous studies, we found that testing increased suggestibility when misinformation was presented via a narrative. Remarkably, when misinformation was presented in questions, testing decreased suggestibility. Copyright © 2013 John Wiley & Sons, Ltd.

  1. 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

  2. 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

  3. 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

  4. Integrated modeling of cryogenic layered highfoot experiments at the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Kritcher, A. L.; Hinkel, D. E.; Callahan, D. A.; Hurricane, O. A.; Clark, D.; Casey, D. T.; Dewald, E. L.; Dittrich, T. R.; Döppner, T.; Barrios Garcia, M. A.; Haan, S.; Berzak Hopkins, L. F.; Jones, O.; Landen, O.; Ma, T.; Meezan, N.; Milovich, J. L.; Pak, A. E.; Park, H.-S.; Patel, P. K. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); and others

    2016-05-15

    Integrated radiation hydrodynamic modeling in two dimensions, including the hohlraum and capsule, of layered cryogenic HighFoot Deuterium-Tritium (DT) implosions on the NIF successfully predicts important data trends. The model consists of a semi-empirical fit to low mode asymmetries and radiation drive multipliers to match shock trajectories, one dimensional inflight radiography, and time of peak neutron production. Application of the model across the HighFoot shot series, over a range of powers, laser energies, laser wavelengths, and target thicknesses predicts the neutron yield to within a factor of two for most shots. The Deuterium-Deuterium ion temperatures and the DT down scattered ratios, ratio of (10–12)/(13–15) MeV neutrons, roughly agree with data at peak fuel velocities <340 km/s and deviate at higher peak velocities, potentially due to flows and neutron scattering differences stemming from 3D or capsule support tent effects. These calculations show a significant amount alpha heating, 1–2.5× for shots where the experimental yield is within a factor of two, which has been achieved by increasing the fuel kinetic energy. This level of alpha heating is consistent with a dynamic hot spot model that is matched to experimental data and as determined from scaling of the yield with peak fuel velocity. These calculations also show that low mode asymmetries become more important as the fuel velocity is increased, and that improving these low mode asymmetries can result in an increase in the yield by a factor of several.

  5. A model for successful research partnerships: a New Brunswick experience.

    Science.gov (United States)

    Tamlyn, Karen; Creelman, Helen; Fisher, Garfield

    2002-01-01

    The purpose of this paper is to present an overview of a partnership model used to conduct a research study entitled "Needs of patients with cancer and their family members in New Brunswick Health Region 3 (NBHR3)" (Tamlyn-Leaman, Creelman, & Fisher, 1997). This partial replication study carried out by the three authors between 1995 and 1997 was a needs assessment, adapted with permission from previous work by Fitch, Vachon, Greenberg, Saltmarche, and Franssen (1993). In order to conduct a comprehensive needs assessment with limited resources, a partnership between academic, public, and private sectors was established. An illustration of this partnership is presented in the model entitled "A Client-Centred Partnership Model." The operations of this partnership, including the strengths, the perceived benefits, lessons learned by each partner, the barriers, and the process for conflict resolution, are described. A summary of the cancer care initiatives undertaken by NBHR3, which were influenced directly or indirectly by the recommendations from this study, is included.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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…

  11. 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.

  12. Proof of concept of an artificial muscle: theoretical model, numerical model, and hardware experiment.

    Science.gov (United States)

    Haeufle, D F B; Günther, M; Blickhan, R; Schmitt, S

    2011-01-01

    Recently, the hyperbolic Hill-type force-velocity relation was derived from basic physical components. It was shown that a contractile element CE consisting of a mechanical energy source (active element AE), a parallel damper element (PDE), and a serial element (SE) exhibits operating points with hyperbolic force-velocity dependency. In this paper, the contraction dynamics of this CE concept were analyzed in a numerical simulation of quick release experiments against different loads. A hyperbolic force-velocity relation was found. The results correspond to measurements of the contraction dynamics of a technical prototype. Deviations from the theoretical prediction could partly be explained by the low stiffness of the SE, which was modeled analog to the metal spring in the hardware prototype. The numerical model and hardware prototype together, are a proof of this CE concept and can be seen as a well-founded starting point for the development of Hill-type artificial muscles. This opens up new vistas for the technical realization of natural movements with rehabilitation devices. © 2011 IEEE

  13. Model-based microwave image reconstruction: simulations and experiments

    International Nuclear Information System (INIS)

    Ciocan, Razvan; Jiang Huabei

    2004-01-01

    We describe an integrated microwave imaging system that can provide spatial maps of dielectric properties of heterogeneous media with tomographically collected data. The hardware system (800-1200 MHz) was built based on a lock-in amplifier with 16 fixed antennas. The reconstruction algorithm was implemented using a Newton iterative method with combined Marquardt-Tikhonov regularizations. System performance was evaluated using heterogeneous media mimicking human breast tissue. Finite element method coupled with the Bayliss and Turkel radiation boundary conditions were applied to compute the electric field distribution in the heterogeneous media of interest. The results show that inclusions embedded in a 76-diameter background medium can be quantitatively reconstructed from both simulated and experimental data. Quantitative analysis of the microwave images obtained suggests that an inclusion of 14 mm in diameter is the smallest object that can be fully characterized presently using experimental data, while objects as small as 10 mm in diameter can be quantitatively resolved with simulated data

  14. 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

  15. 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.

  16. Downscaling ocean conditions: Experiments with a quasi-geostrophic model

    Science.gov (United States)

    Katavouta, A.; Thompson, K. R.

    2013-12-01

    The predictability of small-scale ocean variability, given the time history of the associated large-scales, is investigated using a quasi-geostrophic model of two wind-driven gyres separated by an unstable, mid-ocean jet. Motivated by the recent theoretical study of Henshaw et al. (2003), we propose a straightforward method for assimilating information on the large-scale in order to recover the small-scale details of the quasi-geostrophic circulation. The similarity of this method to the spectral nudging of limited area atmospheric models is discussed. Results from the spectral nudging of the quasi-geostrophic model, and an independent multivariate regression-based approach, show that important features of the ocean circulation, including the position of the meandering mid-ocean jet and the associated pinch-off eddies, can be recovered from the time history of a small number of large-scale modes. We next propose a hybrid approach for assimilating both the large-scales and additional observed time series from a limited number of locations that alone are too sparse to recover the small scales using traditional assimilation techniques. The hybrid approach improved significantly the recovery of the small-scales. The results highlight the importance of the coupling between length scales in downscaling applications, and the value of assimilating limited point observations after the large-scales have been set correctly. The application of the hybrid and spectral nudging to practical ocean forecasting, and projecting changes in ocean conditions on climate time scales, is discussed briefly.

  17. Densification of sintered molybdenum during hot upsetting: experiments and modelling

    International Nuclear Information System (INIS)

    Parteder, E.; Kopp, R.

    1999-01-01

    The densification behaviour of sintered molybdenum is investigated experimentally and by modelling using a pressure dependent plasticity model. Therefore the yield condition of Gurson, extended by Tvergaard is used. The uniaxial compression test is applied to determine the evolution of the density as well as the stress-strain curves for the porous metal. Powder metallurgical molybdenum exhibits closed porosity after consolidation due to sintering with nearly spherical shaped pores. The experimental results show that the densification, especially during the first stage of deformation, is different from that of powder compacts or partially consolidated powder materials with open porosity. During hot upsetting, the pores change their size and shape. This behaviour strongly affects the densification rate. For an accurate prediction of the evolution of the density using Gurson's model, the parameters q 1 and q 2 introduced by Tvergaard, will be defined as internal variables. The use of internal variables is justified by the fact that the pores change their shape during deformation, although the link between the internal variables and the pore shape is not explicitly established in this paper. If the loading is proportional (which means that the ratio of the stress-components does not change with plastic strain), the pore shape can be associated with the applied plastic strain. With this association the parameters q i can be defined as a function from the invariant quantity equivalent plastic strain, which can be used as the internal variable in the finite element simulation. The influence of the porosity on the flow stress at different levels of plastic strain will also be investigated and is used as a second information to fit both parameters q 1 and q 2 . (orig.)

  18. 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.

  19. Modelling system development of risky industry on world experience base

    Directory of Open Access Journals (Sweden)

    O.T. Polishchuk

    2017-12-01

    Full Text Available The paper researches the tendencies and dynamic characteristics of risky business. The means of development stimulation in risky business in the USA are examined. The factors for insurance companies, banks, retirement funds of their investors’ function inability are explained. The multichoice model of economy structure transformation according to the innovative changes and regulatory policy is developed. The authors systematize the factors, which determine the branch attraction for risky investment. Four scenarios for the development of risky industry in Ukraine are studied and the matrix of their development is formed.

  20. Electrostimulated recovery of welded joint durability: experiment and model

    International Nuclear Information System (INIS)

    Semakin, E.V.; Chirakadze, D.Z.; Tsellermaer, V.Ya.; Gromov, V.E.; Sosnin, O.V.

    1997-01-01

    The possibility to increase the durability of welded joints operating under conditions of low cycle fatigue is shown to be brought about using electric current pulses. Experimental method of recovery of operational capability is demonstrated on welded joints of tool steels R6M5 and 40Kh/ The onset of critical stage of fatigue in the welded joint was determined by ultrasonic testing. Then the specimens were treated with 20 Hz electric pulses with amplitude of 250 MA/M 2 for 100 μs. Such treatment resulted in an increase of time to fracture. The phenomenological model of the process is proposed