WorldWideScience

Sample records for classroom-based experimental study

  1. Classroom-Based Phonological Sensitivity Intervention (PSI) Using a Narrative Platform: An Experimental Study of First Graders at Risk for a Reading Disability

    Science.gov (United States)

    Ritter, Michaela J.; Saxon, Terrill F.

    2011-01-01

    The purpose of this study was to assess the effectiveness of classroom-based phonological sensitivity intervention (PSI) using a narrative platform for children in first grade who are at risk for a reading disability. Participants consisted of 59 first graders identified as at risk for later reading impairments. At-risk designation was dictated by…

  2. Encouraging Use of Subordination in Children's Narratives: A Classroom-Based Priming Study

    Science.gov (United States)

    Hesketh, Anne; Serratrice, Ludovica; Ashworth, Rachel

    2016-01-01

    This study investigated the long-term effect of classroom-based input manipulation on children's use of subordination in a story re-telling task; it also explored the role of receptive vocabulary skills and expressive grammatical abilities in predicting the likelihood of priming. During a two-week priming phase, 47 monolingual English-speaking…

  3. Benefits of a Classroom Based Instrumental Music Program on Verbal Memory of Primary School Children: A Longitudinal Study

    Science.gov (United States)

    Rickard, Nikki S.; Vasquez, Jorge T.; Murphy, Fintan; Gill, Anneliese; Toukhsati, Samia R.

    2010-01-01

    Previous research has demonstrated a benefit of music training on a number of cognitive functions including verbal memory performance. The impact of school-based music programs on memory processes is however relatively unknown. The current study explored the effect of increasing frequency and intensity of classroom-based instrumental training…

  4. Classroom-based narrative and vocabulary instruction: results of an early-stage, nonrandomized comparison study.

    Science.gov (United States)

    Gillam, Sandra Laing; Olszewski, Abbie; Fargo, Jamison; Gillam, Ronald B

    2014-07-01

    This nonrandomized feasibility study was designed to provide a preliminary assessment of the impact of a narrative and vocabulary instruction program provided by a speech-language pathologist (SLP) in a regular classroom setting. Forty-three children attending 2 first-grade classrooms participated in the study. Children in each classroom were divided into high- and low-risk subgroups on the basis of their performance on a narrative test. Narrative and vocabulary instruction was provided by an SLP in 1 classroom for three 30-min periods per week for 6 weeks. The children in the experimental classroom made clinically significant improvements on narrative and vocabulary measures; children in the comparison classroom did not. Within the experimental classroom, children in the high-risk subgroup demonstrated greater gains in narration and fewer gains in vocabulary than children in the low-risk subgroup. There were no subgroup differences in the comparison classroom. These preliminary results provide early evidence of the feasibility of implementing a narrative instruction program in a classroom setting. Children at a high risk for language difficulties appeared to profit more from the narrative instruction than from the embedded vocabulary instruction. More extensive research on this instructional program is warranted.

  5. Teaching L2 Spanish Sociopragmatics through Concepts: A Classroom-Based Study

    Science.gov (United States)

    van Compernolle, Rémi A.; Gomez-Laich, Maria Pia; Weber, Ashley

    2016-01-01

    This study explores the teaching of second language (L2) Spanish sociopragmatics through concept-based pragmatics instruction (van Compernolle, 2014). The concepts of self-presentation, social distance, and power were the focus of a pedagogical enrichment program in 2 sections of a beginning-level Spanish class at a northeastern U.S. university.…

  6. Effectiveness of classroom based crew resource management training in the intensive care unit: study design of a controlled trial

    Science.gov (United States)

    2011-01-01

    Background Crew resource management (CRM) has the potential to enhance patient safety in intensive care units (ICU) by improving the use of non-technical skills. However, CRM evaluation studies in health care are inconclusive with regard to the effect of this training on behaviour and organizational outcomes, due to weak study designs and the scarce use of direct observations. Therefore, the aim of this study is to determine the effectiveness and cost-effectiveness of CRM training on attitude, behaviour and organization after one year, using a multi-method approach and matched control units. The purpose of the present article is to describe the study protocol and the underlying choices of this evaluation study of CRM in the ICU in detail. Methods/Design Six ICUs participated in a paired controlled trial, with one pre-test and two post test measurements (respectively three months and one year after the training). Three ICUs were trained and compared to matched control ICUs. The 2-day classroom-based training was delivered to multidisciplinary groups. Typical CRM topics on the individual, team and organizational level were discussed, such as situational awareness, leadership and communication. All levels of Kirkpatrick's evaluation framework (reaction, learning, behaviour and organisation) were assessed using questionnaires, direct observations, interviews and routine ICU administration data. Discussion It is expected that the CRM training acts as a generic intervention that stimulates specific interventions. Besides effectiveness and cost-effectiveness, the assessment of the barriers and facilitators will provide insight in the implementation process of CRM. Trial registration Netherlands Trial Register (NTR): NTR1976 PMID:22073981

  7. Effectiveness of classroom based crew resource management training in the intensive care unit: study design of a controlled trial

    Directory of Open Access Journals (Sweden)

    Kemper Peter F

    2011-11-01

    Full Text Available Abstract Background Crew resource management (CRM has the potential to enhance patient safety in intensive care units (ICU by improving the use of non-technical skills. However, CRM evaluation studies in health care are inconclusive with regard to the effect of this training on behaviour and organizational outcomes, due to weak study designs and the scarce use of direct observations. Therefore, the aim of this study is to determine the effectiveness and cost-effectiveness of CRM training on attitude, behaviour and organization after one year, using a multi-method approach and matched control units. The purpose of the present article is to describe the study protocol and the underlying choices of this evaluation study of CRM in the ICU in detail. Methods/Design Six ICUs participated in a paired controlled trial, with one pre-test and two post test measurements (respectively three months and one year after the training. Three ICUs were trained and compared to matched control ICUs. The 2-day classroom-based training was delivered to multidisciplinary groups. Typical CRM topics on the individual, team and organizational level were discussed, such as situational awareness, leadership and communication. All levels of Kirkpatrick's evaluation framework (reaction, learning, behaviour and organisation were assessed using questionnaires, direct observations, interviews and routine ICU administration data. Discussion It is expected that the CRM training acts as a generic intervention that stimulates specific interventions. Besides effectiveness and cost-effectiveness, the assessment of the barriers and facilitators will provide insight in the implementation process of CRM. Trial registration Netherlands Trial Register (NTR: NTR1976

  8. Understanding and scaffolding Danish schoolteachers’ motivation for using classroom-based physical activity: study protocol for a mixed methods study

    Science.gov (United States)

    Skovgaard, Thomas; Bredahl, Thomas

    2018-01-01

    Introduction The benefits of physical activity for children’s health, both mental and physical, and its positive effects on academic achievement are well established. Research also emphasises that schools could provide a natural setting for regular physical activity. There is, however, a limited amount of knowledge about teachers’ views when it comes to integrating physical activity as part of teaching. The aim of this study is to understand teachers’ motivation for integrating physical activity as part of teaching and to assess their need for guidance and support. Methods and analysis The study uses an explanatory sequential mixed-methods design. Schools from across Denmark are included in the sample. The design comprises two separated phases—a quantitative and qualitative phase. The quantitative phase is guided by the self-determination theory where teachers’ motivation will be measured using the Work Task Motivation Scale for Teachers. The theory of scaffolding guides the qualitative phase, which consists of in-depth interviews with participants selected from the quantitative phase based on levels of motivation and on demographic information. In accordance with the study aims, the analysis of data will identify teachers’ internal and external levels of motivation. The purpose of the qualitative phase is to enhance understanding of teachers’ motivation and of their need for support in the use of physical activity in teaching. Ethics and dissemination All relevant ethics approvals have been acquired. All participants in this study will provide written informed consent prior to data collection. All data emerging from the quantitative and qualitative phase will be anonymised for analysis. Ethics approval was requested from the Regional Committee on Health Research Ethics for Southern Denmark approval ID S-20162000–40 and the Danish Data Protection Agency approval ID 16/15491). The study was deemed not notifiable by both authorities. Trial

  9. Understanding and scaffolding Danish schoolteachers' motivation for using classroom-based physical activity: study protocol for a mixed methods study.

    Science.gov (United States)

    Knudsen, Louise Stjerne; Skovgaard, Thomas; Bredahl, Thomas

    2018-03-14

    The benefits of physical activity for children's health, both mental and physical, and its positive effects on academic achievement are well established. Research also emphasises that schools could provide a natural setting for regular physical activity. There is, however, a limited amount of knowledge about teachers' views when it comes to integrating physical activity as part of teaching. The aim of this study is to understand teachers' motivation for integrating physical activity as part of teaching and to assess their need for guidance and support. The study uses an explanatory sequential mixed-methods design. Schools from across Denmark are included in the sample. The design comprises two separated phases-a quantitative and qualitative phase. The quantitative phase is guided by the self-determination theory where teachers' motivation will be measured using the Work Task Motivation Scale for Teachers. The theory of scaffolding guides the qualitative phase, which consists of in-depth interviews with participants selected from the quantitative phase based on levels of motivation and on demographic information. In accordance with the study aims, the analysis of data will identify teachers' internal and external levels of motivation. The purpose of the qualitative phase is to enhance understanding of teachers' motivation and of their need for support in the use of physical activity in teaching. All relevant ethics approvals have been acquired. All participants in this study will provide written informed consent prior to data collection. All data emerging from the quantitative and qualitative phase will be anonymised for analysis. Ethics approval was requested from the Regional Committee on Health Research Ethics for Southern Denmark approval ID S-20162000-40 and the Danish Data Protection Agency approval ID 16/15491). The study was deemed not notifiable by both authorities. NCT02894346; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated

  10. Experimental studies

    International Nuclear Information System (INIS)

    Cowser, K.E.; Stansbury, P.S.; Poston, J.W.; Deus, S.F.; Chen, W.L.; Roswell, R.L.; Goans, R.E.; Cantrell, J.H. Jr.

    1978-01-01

    Spectral fluence measurements in an adult phantom are reported. A NaI(Tl) probe was used in various locations within the phantom and pulse-height spectra were obtained for seven beam configurations and three generating potentials. Some typical spectra results are presented. A comparison of calculated dose to experimental measurements is presented

  11. Effects of a Classroom-Based Yoga Intervention on Cortisol and Behavior in Second- and Third-Grade Students: A Pilot Study

    Science.gov (United States)

    Butzer, Bethany; Day, Danielle; Potts, Adam; Ryan, Connor; Coulombe, Sarah; Davies, Brandie; Weidknecht, Kimberly; Ebert, Marina; Flynn, Lisa; Khalsa, Sat Bir S.

    2015-01-01

    This uncontrolled pilot study examined the effects of a classroom-based yoga intervention on cortisol concentrations and perceived behavior in children. A 10-week Yoga 4 Classrooms® intervention was implemented in one second- and one third-grade classroom. Students’ salivary cortisol responses were assessed at three time points. Classroom teachers also documented their perceptions of the effects of the intervention on students’ cognitive, social and emotional skills. Second, but not third, graders showed a significant decrease in baseline cortisol from before to after the intervention. Second and third graders both showed significant decreases in cortisol from before to after a cognitive task, but neither grade showed additional decreases from before to after a single yoga class. The second-grade teacher perceived significant improvements in several aspects his/her students’ behavior. The third-grade teacher perceived some, but fewer, improvements in his/her students’ behavior. Results suggest that school-based yoga may be advantageous for stress management and behavior. PMID:25412616

  12. A Pilot Classroom-Based Study of Attention and Working Memory Strategies for Primary-Aged Students

    Science.gov (United States)

    Colmar, Susan; Davis, Nash; Sheldon, Linda

    2016-01-01

    An exploratory applied study, using a set of attention and working memory strategies specifically developed for students and named Memory Mates, was completed with normally developing students attending a primary school. Students in one classroom received the intervention, while the other classroom functioned as a control group. The study was…

  13. Effectiveness of classroom based crew resource management training in the intensive care unit: Study design of a controlled trial

    NARCIS (Netherlands)

    Kemper, P.F.; de Bruijne, M.C.; van Dyck, C.; Wagner, C.

    2011-01-01

    Background: Crew resource management (CRM) has the potential to enhance patient safety in intensive care units (ICU) by improving the use of non-technical skills. However, CRM evaluation studies in health care are inconclusive with regard to the effect of this training on behaviour and

  14. Effectiveness of classroom based crew resource management training in the intensive care unit: study design of a controlled trial.

    NARCIS (Netherlands)

    Kemper, P.F.; Bruijne, M. de; Dyck, C. van; Wagner, C.

    2011-01-01

    Background: Crew resource management (CRM) has the potential to enhance patient safety in intensive care units (ICU) by improving the use of non-technical skills. However, CRM evaluation studies in health care are inconclusive with regard to the effect of this training on behaviour and

  15. Facilitating classroom based interprofessional learning: a grounded theory study of university educators' perceptions of their role adequacy as facilitators.

    Science.gov (United States)

    Derbyshire, Julie A; Machin, Alison I; Crozier, Suzanne

    2015-01-01

    The provision of inter professional learning (IPL) within undergraduate programmes is now well established within many Higher Education Institutions (HEIs). IPL aims to better equip nurses and other health professionals with effective collaborative working skills and knowledge to improve the quality of patient care. Although there is still ambiguity in relation to the optimum timing and method for delivering IPL, effective facilitation is seen as essential. This paper reports on a grounded theory study of university educators' perceptions of the knowledge and skills needed for their role adequacy as IPL facilitators. Data was collected using semi structured interviews with nine participants who were theoretically sampled from a range of professional backgrounds, with varied experiences of education and involvement in facilitating IPL. Constant comparative analysis was used to generate four data categories: creating and sustaining an IPL group culture through transformational IPL leadership (core category), readiness for IPL facilitation, drawing on past interprofessional learning and working experiences and role modelling an interprofessional approach. The grounded theory generated from this study, although propositional, suggests that role adequacy for IPL facilitation is dependent on facilitator engagement in a process of 'transformational interprofessional learning leadership' to create and sustain a group culture. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Child, Teacher and Parent Perceptions of the FRIENDS Classroom-Based Universal Anxiety Prevention Programme: A Qualitative Study.

    Science.gov (United States)

    Skryabina, Elena; Morris, Joanna; Byrne, Danielle; Harkin, Nicola; Rook, Sarah; Stallard, Paul

    2016-01-01

    School-based mental health prevention programmes can be effective but their adoption within schools will depend on their social acceptability. We report a qualitative evaluation summarising the views of children (115), parents (20) and school staff (47) about a universal school-based anxiety prevention programme FRIENDS. This study was conducted as part of a large scale randomised controlled trial ( n  = 1362) involving 40 schools in the UK providing primary education to children aged 7-11. Reported overall experience of the programme was very positive, with all three major components of the cognitive behaviour therapy programme (emotional, cognitive, and behavioural) being accepted well and understood by children. The programme was considered to be enjoyable and valuable in teaching children important skills, particularly emotional regulation and coping. Children provided examples of using the skills learned during FRIENDS to manage their emotions and solve problems. However, teachers were concerned that the programme overlapped with the current school curriculum, required additional time and almost half were unable to identify any tangible changes in the children's behaviour. Whilst this paper provides evidence to support the social validity of the FRIENDS anxiety prevention programme, the concerns raised by teachers question the longer-term sustainability of the programme.

  17. Study protocol for a group randomized controlled trial of a classroom-based intervention aimed at preventing early risk factors for drug abuse: integrating effectiveness and implementation research.

    Science.gov (United States)

    Poduska, Jeanne; Kellam, Sheppard; Brown, C Hendricks; Ford, Carla; Windham, Amy; Keegan, Natalie; Wang, Wei

    2009-09-02

    While a number of preventive interventions delivered within schools have shown both short-term and long-term impact in epidemiologically based randomized field trials, programs are not often sustained with high-quality implementation over time. This study was designed to support two purposes. The first purpose was to test the effectiveness of a universal classroom-based intervention, the Whole Day First Grade Program (WD), aimed at two early antecedents to drug abuse and other problem behaviors, namely, aggressive, disruptive behavior and poor academic achievement. The second purpose--the focus of this paper--was to examine the utility of a multilevel structure to support high levels of implementation during the effectiveness trial, to sustain WD practices across additional years, and to train additional teachers in WD practices. The WD intervention integrated three components, each previously tested separately: classroom behavior management; instruction, specifically reading; and family-classroom partnerships around behavior and learning. Teachers and students in 12 schools were randomly assigned to receive either the WD intervention or the standard first-grade program of the school system (SC). Three consecutive cohorts of first graders were randomized within schools to WD or SC classrooms and followed through the end of third grade to test the effectiveness of the WD intervention. Teacher practices were assessed over three years to examine the utility of the multilevel structure to support sustainability and scaling-up. The design employed in this trial appears to have considerable utility to provide data on WD effectiveness and to inform the field with regard to structures required to move evidence-based programs into practice. NCT00257088.

  18. Study protocol for a group randomized controlled trial of a classroom-based intervention aimed at preventing early risk factors for drug abuse: integrating effectiveness and implementation research

    Directory of Open Access Journals (Sweden)

    Keegan Natalie

    2009-09-01

    Full Text Available Abstract Background While a number of preventive interventions delivered within schools have shown both short-term and long-term impact in epidemiologically based randomized field trials, programs are not often sustained with high-quality implementation over time. This study was designed to support two purposes. The first purpose was to test the effectiveness of a universal classroom-based intervention, the Whole Day First Grade Program (WD, aimed at two early antecedents to drug abuse and other problem behaviors, namely, aggressive, disruptive behavior and poor academic achievement. The second purpose--the focus of this paper--was to examine the utility of a multilevel structure to support high levels of implementation during the effectiveness trial, to sustain WD practices across additional years, and to train additional teachers in WD practices. Methods The WD intervention integrated three components, each previously tested separately: classroom behavior management; instruction, specifically reading; and family-classroom partnerships around behavior and learning. Teachers and students in 12 schools were randomly assigned to receive either the WD intervention or the standard first-grade program of the school system (SC. Three consecutive cohorts of first graders were randomized within schools to WD or SC classrooms and followed through the end of third grade to test the effectiveness of the WD intervention. Teacher practices were assessed over three years to examine the utility of the multilevel structure to support sustainability and scaling-up. Discussion The design employed in this trial appears to have considerable utility to provide data on WD effectiveness and to inform the field with regard to structures required to move evidence-based programs into practice. Trial Registration Clinical Trials Registration Number: NCT00257088

  19. Outcomes of classroom-based team training interventions for multiprofessional hospital staff. A systematic review

    DEFF Research Database (Denmark)

    Rabøl, Louise Isager; Østergaard, Doris; Mogensen, Torben

    2010-01-01

    Several studies show that communication errors in healthcare teams are frequent and can lead to adverse events. Team training has been suggested as a way to safer communication and has been implemented in healthcare as classroom-based or simulation-based team training or a combination of both. Th....... The objective of this paper is to systematically review studies evaluating the outcomes of classroom-based multiprofessional team training for hospital staff.......Several studies show that communication errors in healthcare teams are frequent and can lead to adverse events. Team training has been suggested as a way to safer communication and has been implemented in healthcare as classroom-based or simulation-based team training or a combination of both...

  20. Classroom-Based Assessment and the Issue of Continuity between Primary and Secondary School Languages Programs

    Science.gov (United States)

    Hill, Kathryn

    2010-01-01

    This article presents selected findings from an ethnographic study of classroom-based assessment practices in languages classrooms (Indonesian) in the final year of primary (Year 6) and the first year of secondary (Year 7), respectively. In particular, the paper focuses on differences between the respective year levels in how learning was assessed…

  1. Project EX-India: A classroom-based tobacco use prevention and cessation intervention program.

    Science.gov (United States)

    Sidhu, Anupreet Kaur; Sussman, Steve; Tewari, Abha; Bassi, Shalini; Arora, Monika

    2016-02-01

    Tobacco use experimentation is most frequent between the ages of 15–24 in India. Therefore, programming to counteract tobacco use among adolescents is needed. There is a lack of evidence-based teen tobacco use prevention and cessation programs. The current study provides an outcome evaluation of the Project EX tobacco use prevention and cessation program among Indian adolescents (16–18 years). An eight-session classroom-based curriculum was adapted to the Indian context and translated from English to Hindi (local language). Next, it was tested using a quasi-experimental design with 624 Indian students at baseline, involving two program and two control schools, with a three-month post-program follow-up. Project EX involves motivation enhancement (e.g., talk shows and games) and coping skills (e.g., complementary and alternative medicine) components. Program participants rated complementary and alternative medicine (CAM) activities like meditation, yoga and healthy breathing higher than talk shows and games. Compared to the standard care control condition, the program condition revealed a prevention effect, but not a cessation effect. Implications for prevention/cessation programming among Indian teens are discussed. This study was approved by the Independent Ethics Committee, Mumbai.

  2. clinical and experimental study

    OpenAIRE

    Tornow, Christoph

    2011-01-01

    Posterior capsule opacity (PCO) is a frequent complication in extracapsular cataract extraction in conjunction with an intraocular lens implant. Different studies have shown that a reduction in PCO frequency can be achieved via a number of factors. Lens design is a significant criterion in this process. In this study, two multifocal intraocular lenses (MIOLs) were compared. The design of these lenses differed due to their varying optical principles. They are the refractive MIOL A...

  3. Experimental studies of electron capture

    International Nuclear Information System (INIS)

    Pedersen, E.H.

    1983-01-01

    This thesis discusses the main results of recent experimental studies of electron capture in asymmetric collisions. Most of the results have been published, but the thesis also contains yet unpublished data, or data presented only in unrefereed conference proceedings. The thesis aims at giving a coherent discussion of the understanding of the experimental results, based first on simple qualitative considerations and subsequently on quantitative comparisons with the best theoretical calculations currently available. (Auth.)

  4. [Experimental studies of micromotor headpieces].

    Science.gov (United States)

    Kanaev, V F; Repin, V A

    1982-01-01

    Experimental studies of handpieces for micromotors have been performed to make more precise their operating parameters. The special stand has been used for the measurements of the following data: head temperature, power losses in handpieces at no-load, and operating power required for machining by means of spherical burrs. The experimental results made it possible to specify more exactly the range of handpiece rotational speeds and to select optimum loads under reliability testing.

  5. Classroom-based physical activity breaks and children’s attention: cognitive engagement works!

    Directory of Open Access Journals (Sweden)

    Mirko Schmidt

    2016-10-01

    Full Text Available Classroom-based physical activity breaks are postulated to positively impact children’s attention during their school day. However, empirical evidence for this claim is scarce and the role of cognitive engagement in enhancing children’s attentional performance is unexplored in studies on physical activity breaks. The aim of the present study was therefore to disentangle the separate and/or combined effects of physical exertion and cognitive engagement induced by physical activity breaks on primary school children’s attention. In addition, the role of children’s affective reactions to acute interventions at school was investigated. Using a 2 × 2 between-subjects experimental design, 92 children between the ages of 11 and 12 years (M = 11.77, SD = 0.41 were randomly assigned to one of four experimental conditions: (1 combo group (physical activity with high cognitive demands, (2 cognition group (sedentary with high cognitive demands, (3 physical group (physical activity with low cognitive demands, and (4 control group (sedentary with low cognitive demands. Attention and affect were measured before and immediately after a 10-minute intervention. ANCOVAs revealed that whereas physical exertion had no effect on any measure of children’s attentional performance, cognitive engagement was the crucial factor leading to increased focused attention and enhanced processing speed. Mediational analyses showed that changes in positive affect during the interventions mediated the effect between cognitive engagement and focused attention as well as between cognitive engagement and processing speed. These surprising results are discussed in the light of theories predicting both facilitating and deteriorative effects of positive affect on cognitive performance.

  6. EXPERIMENTAL STUDY IN NATURAL CONVECTION

    African Journals Online (AJOL)

    PROF. BARTH EKWEME

    The study of thermal and ventilation parameters, obtained in a transient, laminar solar chimney of reduced dimensions, (1 < m <3) m with a square collector (side = 2m) is presented. Experimental measurements has been made to determine the temperature of the absorber and the fluid in the collector, it is shown that at the ...

  7. EBTS: DESIGN AND EXPERIMENTAL STUDY

    International Nuclear Information System (INIS)

    PIKIN, A.; ALESSI, J.; BEEBE, E.; KPONOU, A.; PRELEC, K.; KUZNETSOV, G.; TIUNOV, M.

    2000-01-01

    Experimental study of the BNL Electron Beam Test Stand (EBTS), which is a prototype of the Relativistic Heavy Ion Collider (RHIC) Electron Beam Ion Source (EBIS), is currently underway. The basic physics and engineering aspects of a high current EBIS implemented in EBTS are outlined and construction of its main systems is presented. Efficient transmission of a 10 A electron beam through the ion trap has been achieved. Experimental results on generation of multiply charged ions with both continuous gas and external ion injection confirm stable operation of the ion trap

  8. People counting in classroom based on video surveillance

    Science.gov (United States)

    Zhang, Quanbin; Huang, Xiang; Su, Juan

    2014-11-01

    Currently, the switches of the lights and other electronic devices in the classroom are mainly relied on manual control, as a result, many lights are on while no one or only few people in the classroom. It is important to change the current situation and control the electronic devices intelligently according to the number and the distribution of the students in the classroom, so as to reduce the considerable waste of electronic resources. This paper studies the problem of people counting in classroom based on video surveillance. As the camera in the classroom can not get the full shape contour information of bodies and the clear features information of faces, most of the classical algorithms such as the pedestrian detection method based on HOG (histograms of oriented gradient) feature and the face detection method based on machine learning are unable to obtain a satisfied result. A new kind of dual background updating model based on sparse and low-rank matrix decomposition is proposed in this paper, according to the fact that most of the students in the classroom are almost in stationary state and there are body movement occasionally. Firstly, combining the frame difference with the sparse and low-rank matrix decomposition to predict the moving areas, and updating the background model with different parameters according to the positional relationship between the pixels of current video frame and the predicted motion regions. Secondly, the regions of moving objects are determined based on the updated background using the background subtraction method. Finally, some operations including binarization, median filtering and morphology processing, connected component detection, etc. are performed on the regions acquired by the background subtraction, in order to induce the effects of the noise and obtain the number of people in the classroom. The experiment results show the validity of the algorithm of people counting.

  9. The Impact of Classroom-Based Meditation Practice on Cognitive Engagement, Mindfulness and Academic Performance of Undergraduate College Students

    Science.gov (United States)

    Napora, Lisa

    2013-01-01

    This study explored the potential of classroom-based meditation practice as a tool to facilitate learning. Moreover, the impact of meditation on cognitive engagement, mindfulness and academic performance of undergraduate college students was investigated. Additionally, the relationships between mindfulness and cognitive engagement, and between…

  10. Experimental studies of minienvironment types

    International Nuclear Information System (INIS)

    Eissler, W.; Schneider, H.

    1994-01-01

    Various minienvironment types are available offering different features at quite different costs. MEISSNER+WURST performed in its JESSI project experimental tests to examine the isolation capabilities and the recovery time of minienvironments and the influence of manual handling and maintenance on the minienvironment cleanliness. An isolation factor up to 1 million was measured in the experiments. The Custom Tailored Minienvironment has the best protection against external and internal particle sources. Critical points in the design and the installation of minienvironments were identified. The results of air flow visualization studies were confirmed by airflow simulations. The result of the studies allow a classification of minienvironment types according to their cleanliness achievements

  11. Experimental study of neoclassical currents

    International Nuclear Information System (INIS)

    Zarnstorff, M.C.; Prager, S.C.

    1985-05-01

    A detailed experimental study is presented of the bootstrap and Pfirsch-Schlueter currents that are predicted by neoclassical transport theory. In a toroidal octupole, on magnetic surfaces within the separatrix, the observed parallel plasma currents are in excellent quantitative agreement with neoclassical theory with regard to the spatial structure (along a magnetic surface), collisionality dependence and toroidal magnetic field dependence. On magnetic surfaces outside the separatrix, the ion portion of the parallel current is in agreement with neoclassical theory but the electron parallel current is observed to obtain a unidirectional component which deviates from and exceeds the theoretical prediction

  12. Experimental Study on radiation myelopathy

    International Nuclear Information System (INIS)

    Kaneko, Itsuo; Matsushima, Hideno; Yamada, Teruyo

    1979-01-01

    Experimental radiation myelopathy was carried out useing rats. This studies were done refering the effect to skin, the body weight, the status of the paralysis and the capillary densities of the cervical cords. The quadriplegia was seen on the animals which were irradiated over 4000 rad. The vacuoal degeneration was observed on the cervical cords which were irradiated over 4000 rad. The capillary densities of gray matter and white matter decreased finally in proportions to the irradiation dose. The vacuoal degeneration was recognized on the cervical cord in which the capillary density decreased to under 70 per cent of normal density. Decrease of the capillary density is seemed to be the one of the cause of the paralysis. (author)

  13. Experimental study of virtual impactors

    International Nuclear Information System (INIS)

    Yule, T.J.; Broniarck, C.G.

    1979-01-01

    Virtual impactors are currently being used in a number of instruments to separate an aerosol into different size ranges. The virtual impactor is a variation of the standard impactor in which the impaction surface is replaced by an orifice into which particles can pass and be collected or counted. We have made an experimental study of the collection characteristics of virtual impactors. The parameters varied included: acceleration nozzle-to-collection probe distance, the ratio of the collection probe-to-acceleration nozzle diameters, and the ratio of collection probe-to-inlet flows. Measurements were also made with different collection probe geometries. It was found that it is possible to parameterize much of the data by introduction of the Stokes number and an effective minor flow collection efficiency. One disadvantage of the virtual impactor is that in the transition region particles are collected on the inside walls of the collection probe near the probe tip. The amount that is collected is a sensitive function of the probe geometry

  14. Inverted annular flow experimental study

    International Nuclear Information System (INIS)

    De Jarlais, G.; Ishii, M.

    1985-04-01

    Steady-state inverted annular flow of Freon 113 in up flow was established in a transparent test section. Using a special inlet configuration consisting of long aspect-ratio liquid nozzles coaxially centered within a heated quartz tube, idealized inverted annular flow initial geometry (cylindrical liquid core surrounded by coaxial annulus of gas) could be established. Inlet liquid and gas flowrates, liquid subcooling, and gas density (using various gas species) were measured and varied systematically. The hydrodynamic behavior of the liquid core, and the subsequent downstream break-up of this core into slugs, ligaments and/or droplets of various sizes, was observed. In general, for low inlet liquid velocities it was observed that after the initial formation of roll waves on the liquid core surface, an agitated region of high surface area, with attendant high momentum and energy transfers, occurs. This agitated region appears to propagate downsteam in a quasi-periodic pattern. Increased inlet liquid flow rates, and high gas annulus flow rates tend to diminish the significance of this agitated region. Observed inverted annular flow (and subsequent downstream flow pattern) hydrodynamic behavior is reported, and comparisons are drawn to data generated by previous experimenters studying post-CHF flow

  15. Experimental rigs for MHD studies

    International Nuclear Information System (INIS)

    Venkataramani, N.; Jayakumar, R.; Iyer, D.R.; Dixit, N.S.

    1976-01-01

    An MHD experimental rig is a miniature MHD installation consisting of basic equipments necessary for specific investigations. Some of the experimental rigs used in the investigations being carried out at the Bhabha Atomic Research Centre, Bombay (India) are dealt with. The experiments included diagnostics and evaluation of materials in seeded combustion plasmas and argon plasmas. The design specifications, schematics and some of the results of the investigations are also mentioned. (author)

  16. Classroom-based science research at the introductory level: changes in career choices and attitude.

    Science.gov (United States)

    Harrison, Melinda; Dunbar, David; Ratmansky, Lisa; Boyd, Kimberly; Lopatto, David

    2011-01-01

    Our study, focused on classroom-based research at the introductory level and using the Phage Genomics course as the model, shows evidence that first-year students doing research learn the process of science as well as how scientists practice science. A preliminary but notable outcome of our work, which is based on a small sample, is the change in student interest in considering different career choices such as graduate education and science in general. This is particularly notable, as previous research has described research internships as clarifying or confirming rather than changing undergraduates' decisions to pursue graduate education. We hypothesize that our results differ from previous studies of the impact of engaging in research because the students in our study are still in the early stages of their undergraduate careers. Our work builds upon the classroom-based research movement and should be viewed as encouraging to the Vision and Change in Undergraduate Biology Education movement advocated by the American Association for the Advancement of Science, the National Science Foundation, and other undergraduate education stakeholders.

  17. A Qualitative Process Evaluation of Classroom-Based Cognitive Behaviour Therapy to Reduce Adolescent Depression

    Directory of Open Access Journals (Sweden)

    John A. Taylor

    2014-06-01

    Full Text Available Small scale trials indicate that classroom-based Cognitive Behaviour Therapy (CBT for adolescents has good reach and can help prevent depression. However, under more diverse everyday conditions, such programmes tend not to show such positive effects. This study examined the process of implementing a classroom-based CBT depression prevention programme as part of a large (n = 5,030 randomised controlled trial across eight UK secondary schools which was not found to be effective (PROMISE, ISRCTN19083628. The views of young people (n = 42, teachers (n = 12 and facilitators (n = 16 involved in the Resourceful Adolescent Programme (RAP were obtained via focus groups and interviews which were thematically analysed. The programme was considered to be well structured and contain useful content, particularly for younger pupils. However, challenges associated with implementation were its age appropriateness for all year groups, its perceived lack of flexibility, the consistency of quality of delivery, the competing demands for teacher time and a culture where academic targets were prioritised over personal, social and health education. Whilst schools are convenient locations for introducing such programmes and allow good reach, the culture around improving well-being of young people in schools, increasing engagement with teachers and young people and sustaining such programmes are issues that need addressing.

  18. The role of friends' disruptive behavior in the development of children's tobacco experimentation: results from a preventive

    NARCIS (Netherlands)

    van Lier, P.A.C.; Huizink, A.C.; Vuijk, P.J.

    2011-01-01

    Having friends who engage in disruptive behavior in childhood may be a risk factor for childhood tobacco experimentation. This study tested the role of friends' disruptive behavior as a mediator of the effects of a classroom based intervention on children's tobacco experimentation. 433 Children (52%

  19. A comparative analysis of on-line and classroom-based instructional formats for teaching social work research

    OpenAIRE

    David Westhuis; Philip M. Ouellette; Corey L. Pfahler

    2006-01-01

    Research comparing courses taught exclusively in traditional face-to-face settings versus courses taught entirely online have shown similar levels of student satisfaction. This article reports findings from a comparative study of student achievement in research skills from classes using two different instructional formats. One group used a classroom-based instructional format and the other group used an online web-based instructional format. Findings indicate that there were no statistically ...

  20. Experimental studies on cancer chemotherapy

    International Nuclear Information System (INIS)

    1976-08-01

    The further development of the chemotherapy of cancer in the experimental and clinical fields necessitates a profound knowledge of its chemical, biochemical and pharmacological fundamentals and the mechanism of physiological and pathological growth processes. The 'Arbeitsgemeinschaft Zytostatika' includes chemists, biochemists, pharmacologists, molecular biologists, physicians and immunologists of various scientific institutes and clinics in the Federal Republic of Germany and in West Berlin. It is their aim to carry out basic research as well as clinical-orientated research in the field of the chemotherapy of cancer. In the 15 years of cooperation, fundamental knowledge was gained, especially in the field of the cytotoxic specificity and cancerotoxic selectivity of alkylating cytostatics. New cytostatics with a greater oncostatic selectivity and an altered spectrum of activity were tested and greater knowledge was won on the molecular-biological prerequisites of a rational drug design. (orig.) [de

  1. Experimental studies of morphology development

    International Nuclear Information System (INIS)

    Whitton, J.L.

    1986-01-01

    This contribution is a resume of the approximately eight years of experimental investigation of ion beam-induced modification of metal surfaces. The aim, from the beginning, was to make a detailed series of experiments with well defined controllable parameters in an attempt to establish the mechanism responsible for the production of the topographical features observed so frequently on ion-bombarded surfaces of metals. Typically, for the initial system, 40 keV argon ions directed on to copper, the sputtering yield is fairly constant from normal angle of incidence to about 30 0 , rising fairly smoothly to a maximum at 80 0 , then dropping rapidly to zero at around 82 0 . A very strong grain orientation effect was observed in the early experiments. (Auth.)

  2. Experimental studies of nuclear astrophysics

    International Nuclear Information System (INIS)

    He Jianjun; Zhou Xiaohong; Zhang Yuhu

    2013-01-01

    Nuclear astrophysics is an interdisciplinary subject combining micro-scale nuclear physics and macro-scale astrophysics. Its main aims are to understand the origin and evolution of the elements in the universe, the time scale of stellar evolution, the stellar environment and sites, the energy generation of stars from thermonuclear processes and its impact on stellar evolution and the mechanisms driving astrophysical phenomena, and the structure and property of compact stars. This paper presents the significance and current research status of nuclear astrophysics; we introduce some fundamental concepts, the nuclear physics input parameters required by certain astrophysics models, and some widely-used experimental approaches in nuclear astrophysics research. The potential and feasibility of research in this field using China’s current and planned large-scale scientific facilities are analyzed briefly. Finally, the prospects of the establishing a deep underground science and engineering laboratory in China are envisaged. (authors)

  3. Bringing Classroom-Based Assessment into the EFL classroom

    Directory of Open Access Journals (Sweden)

    Andrew Finch

    2012-01-01

    Full Text Available   This paper describes how English as a Foreign Language (EFL teachers can bring reliable, valid, user-friendly assessment into their classrooms, and thus improve the quality of learning that occurs there. Based on the experience of the author as a an EFL teacher and teacher-trainer, it is suggested that the promotion and development of autonomy, intrinsic motivation, and self-esteem that takes place in a Classroom-Based Assessment (CBA environment facilitates an holistic approach to language learning and prepares the students for the high-stakes tests that often determine their motivation for learning English. Rather than relying on the memorization of language code, form, lexis, and prepared answers, students who have learned in a CBA environment are able to self-assess, peer-assess, build portfolios, and edit their own work. Not only does this reduce the assessment burden on the teacher, but it also develops the skills of problem-solving, critical thinking, and summarization in the students, in addition to a heightened awareness of the language-learning process. By learning how to set goals, assess their achievements, and reflect on their future learning needs, students become more efficient language learners. While acknowledging the place of standardized, summative tests in contemporary society, it is suggested that CBA in the EFL classroom can enhance long-term learning and consequently enable and empower students to prepare for their future learning needs.

  4. Experimental studies of neutrino oscillations

    CERN Document Server

    Kajita, Takaaki

    2016-01-01

    The 2015 Nobel Prize in physics has been awarded to Takaaki Kajita and Arthur McDonald "for the discovery of neutrino oscillations, which shows that neutrinos have mass". Takaaki Kajita of Tokyo University is a Japanese physicist, known for neutrino experiments at the Kamiokande and its successor, Super-Kamiokande. This volume of collected works of Kajita on neutrino oscillations provides a good glimpse into as well as a record of the rise and the role of Asian research in the frontiers of neutrino physics. Japan is now a major force in the study of the 3 families of neutrinos. Much remains to be done to clarify the Dirac vs. Majorana nature of the neutrino, and the cosmological implications of the neutrino. The collected works of Kajita and his Super-Kamiokande group will leave an indelible foot-print in the history of big and better science.

  5. Experimental study of ozone synthesis

    International Nuclear Information System (INIS)

    Garamoon, A A; Elakshar, F F; Nossair, A M; Kotp, E F

    2002-01-01

    A silent discharge ozonizer has been constructed with a design that enables the study of ozone concentration behaviour as a function of different parameters when oxygen used as a working gas. The behaviour of ozone concentration as a function of discharge current density has four characteristic regions. The concentration is enhanced by more than threefold whenever gas pressure is reduced by a factor of two. The flow rate of the working gas is a more effective parameter on ozone concentration than the gas pressure. When the flow rate is kept constant, and the pressure is decreased by 100%, the ozone concentration increases by only 10%. On the other hand, when the flow rate is decreased by 13%, the ozone concentration increases by 200%, whenever the gas pressure is kept constant. The concentration is nearly doubled when the gap space is increased by four times under the same conditions. The length of the discharge region, the thickness and the dielectric constant of the insulating materials are found to have a considerable effect on the generated ozone concentration. Also, the ozone concentration is ten times less when air is used instead of oxygen as a working gas. A maximum efficiency of 185 g/kWh, is obtained for the present system

  6. More explicit communication after classroom-based crew resource management training: results of a pragmatic trial.

    Science.gov (United States)

    Verbeek-van Noord, Inge; de Bruijne, Martine C; Twisk, Jos W R; van Dyck, Cathy; Wagner, Cordula

    2015-02-01

    Aviation-based crew resource management trainings to optimize non-technical skills among professionals are often suggested for health care as a way to increase patient safety. Our aim was to evaluate the effect of a 2-day classroom-based crew resource management (CRM) training at emergency departments (EDs) on explicit professional oral communication (EPOC; non-technical skills). A pragmatic controlled before-after trial was conducted. Four EDs of general teaching hospitals were recruited (two intervention and two control departments). ED nurses and ED doctors were observed on their non-technical skills by means of a validated observation tool (EPOC). Our main outcome measure was the amount of EPOC observed per interaction in 30 minutes direct observations. Three outcome measures from EPOC were analysed: human interaction, anticipation on environment and an overall EPOC score. Linear and logistic mixed model analyses were performed. Models were corrected for the outcome measurement at baseline, days between training and observation, patient safety culture and error management culture at baseline. A statistically significant increase after the training was found on human interaction (β=0.27, 95% CI 0.08-0.49) and the overall EPOC score (β=0.25, 95% CI 0.06-0.43), but not for anticipation on environment (OR=1.19, 95% CI .45-3.15). This means that approximately 25% more explicit communication was shown after CRM training. We found an increase in the use of CRM skills after classroom-based crew resource management training. This study adds to the body of evidence that CRM trainings have the potential to increase patient safety by reducing communication flaws, which play an important role in health care-related adverse events. © 2014 John Wiley & Sons, Ltd.

  7. Combined Teaching Method: An Experimental Study

    Science.gov (United States)

    Kolesnikova, Iryna V.

    2016-01-01

    The search for the best approach to business education has led educators and researchers to seek many different teaching strategies, ranging from the traditional teaching methods to various experimental approaches such as active learning techniques. The aim of this experimental study was to compare the effects of the traditional and combined…

  8. Experimental studies of the quantum chromodynamics phase ...

    Indian Academy of Sciences (India)

    2015-05-06

    BES) ... Experimental studies of the QCD phase diagram at the STAR experiment .... However, the observed difference between v2 of particles and antiparticles could .... The grey band at the right corresponds to systematic.

  9. Hepatic encephalopathy: experimental studies on the pathogenesis

    NARCIS (Netherlands)

    R.J. de Knegt (Robert)

    1993-01-01

    textabstractAims of this thesis: 1. To study, in rabbits, the suitability of experimental acute liver failure and acute hyperammonemia simulating acute liver failure for the study of hepatic encephalopathy and ammonia toxicity. 2. To study glutamate neurotransmission in rabbits with acute liver

  10. Experimental design of a waste glass study

    International Nuclear Information System (INIS)

    Piepel, G.F.; Redgate, P.E.; Hrma, P.

    1995-04-01

    A Composition Variation Study (CVS) is being performed to support a future high-level waste glass plant at Hanford. A total of 147 glasses, covering a broad region of compositions melting at approximately 1150 degrees C, were tested in five statistically designed experimental phases. This paper focuses on the goals, strategies, and techniques used in designing the five phases. The overall strategy was to investigate glass compositions on the boundary and interior of an experimental region defined by single- component, multiple-component, and property constraints. Statistical optimal experimental design techniques were used to cover various subregions of the experimental region in each phase. Empirical mixture models for glass properties (as functions of glass composition) from previous phases wee used in designing subsequent CVS phases

  11. Experimental radiation carcinogenesis is studies at NIRS

    International Nuclear Information System (INIS)

    Sado, Toshihiko

    1992-01-01

    Experimental radiation carcinogenesis studies conducted during the past decade at NIRS are briefly reviewed. They include the following: 1) Age dependency of susceptibility to radiation carcinogenesis. 2) Radiation-induced myeloid leukemia. 3) Mechanism of fractionated X-irradiation (FX) induced thymic lymphomas. 4) Significance of radiation-induced immunosuppression in radiation carcinogenesis in vivo. 5) Other ongoing studies. (author)

  12. Experimental study on rapid embankment construction methods

    International Nuclear Information System (INIS)

    Hirano, Hideaki; Egawa, Kikuji; Hyodo, Kazuya; Kannoto, Yasuo; Sekimoto, Tsuyoshi; Kobayashi, Kokichi.

    1982-01-01

    In the construction of a thermal or nuclear power plant in a coastal area, shorter embankment construction period has come to be called for recently. This tendency is remarkable where construction period is limited due to meteorological or sea conditions. To meet this requirement, the authors have been conducting basic experimental studies on two methods for the rapid execution of embankment construction, that is, Steel Plate Cellular Bulkhead Embedding Method and Ship Hull Caisson Method. This paper presents an outline of the results of the experimental study on these two methods. (author)

  13. A combined experimental and theoretical study

    Indian Academy of Sciences (India)

    A combined theoretical and experimental study was also performed, which demonstrated that the clus- ters 1–3 with ... silica gel TLC plates (MERCK TLC Plates). The NMR .... tronic μ3-Se and maintains the same number of clus- ter valance ...

  14. Experimental study of collective processes in REB

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanov, L Yu; Sominskij, G G [St. Petersburg Technical University (Russian Federation)

    1997-12-31

    The role of collective processes at relativistic electron beam formation and transportation was studied experimentally by using new low-disturbing techniques. In particular, local mirror-like enhancements of the external magnetic field were introduced and their influence of the beam space charge oscillations was investigated. The amplitude-frequency characteristics of the space charge oscillations in different parts of the drift channel were measured by a set of high-frequency probes. On the base of the collected experimental data two possible mechanisms of development of the beam space charge oscillations are discussed: the two-stream instability and the diocotron instability. (J.U.). 2 figs., 4 refs.

  15. Experimental study of the natural circulation phenomena

    International Nuclear Information System (INIS)

    Sabundjian, Gaiane; Andrade, Delvonei Alves de; Umbehaun, Pedro E.; Torres, Walmir M.; Castro, Alfredo Jose Alvim de; Belchior Junior, Antonio; Rocha, Ricardo Takeshi Vieira da; Damy, Osvaldo Luiz de Almeida; Torres, Eduardo

    2006-01-01

    The objective of this paper is to study the natural circulation in experimental loops and extend the results to nuclear facilities. New generation of compact nuclear power plants use the natural circulation as cooling and residual heat removal systems in case of accidents or shutdown. Lately the interest in this phenomenon, by scientific community, has increased. The experimental loop, described in this paper, was assembled at Escola Politecnica - USP at the Chemical Engineering Department. It is the goal to generate information to help with the understanding of the one and two phase natural circulation phenomena. Some experiments were performed with different levels of heat power and different flow of the cooling water at the secondary circuit. The data generated from these experiments are going to be used to validate some computational thermal hydraulic codes. Experimental results for one and two phase regimes are presented as well as the proposed model to simulate the flow regimes with the RELAP5 code. (author)

  16. Experimental studies of generalized parton distributions

    International Nuclear Information System (INIS)

    Kabuss, E.M.

    2014-01-01

    Generalized parton distributions (GPD) provide a new way to study the nucleon structure. Experimentally they can be accessed using hard exclusive processes such as deeply virtual Compton scattering and meson production. First insights to GPDs were already obtained from measurements at DESY, JLAB and CERN, while new ambitious studies are planned at the upgraded JLAB at 12 GeV and at CERN. Here, some emphasis will be put onto the planned COMPASS II programme. (author)

  17. Experimental and computational study of thaumasite structure

    Energy Technology Data Exchange (ETDEWEB)

    Scholtzová, Eva, E-mail: Eva.Scholtzova@savba.sk [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava (Slovakia); Kucková, Lenka; Kožíšek, Jozef [Department of Physical Chemistry, Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37 Bratislava (Slovakia); Pálková, Helena [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava (Slovakia); Tunega, Daniel [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava (Slovakia); Institute for Soil Science, University of Natural Resources and Life Sciences, Peter-Jordanstrasse 82, A-1190 Wien (Austria)

    2014-05-01

    The structure of thaumasite has been studied experimentally by means of a single crystal X-ray diffraction and FTIR methods, and theoretically using density functional theory (DFT) method. Very good agreement was achieved between calculated and experimental structural parameters. In addition, calculations offered the refinement of the positions of the hydrogen atoms. The detailed analysis of the hydrogen bonds existing in the thaumasite structure has been performed. Several types of hydrogen bonds have been classified. The water molecules coordinating Ca{sup 2+} cation act as proton donors in moderate O-H···O hydrogen bonds formed with CO₃⁻²and SO₄⁻² anions. The multiple O-H···O hydrogen bonds exist among water molecules themselves. Finally, relatively weak hydrogen bonds form water molecules with the OH groups from the coordination sphere of the Si(OH)₆⁻² anion. Further, calculated vibrational spectrum allowed complete assignment of all vibrational modes which are not available from the experimental spectrum that has a complex structure with overlapped bands, especially below 1500 cm⁻¹. Highlights: • The thaumasite structure was studied experimentally and using DFT method. • We used DFT method for the refinement of the positions of hydrogen atoms. • A detailed analysis of the hydrogen bonds was done. • A complete assignment of all bands to particular types of vibrations was done.

  18. Experimental study of structural response to earthquakes

    International Nuclear Information System (INIS)

    Clough, R.W.; Bertero, V.V.; Bouwkamp, J.G.; Popov, E.P.

    1975-01-01

    The objectives, methods, and some of the principal results obtained from experimental studies of the behavior of structures subjected to earthquakes are described. Although such investigations are being conducted in many laboratories throughout the world, the information presented deals specifically with projects being carried out at the Earthquake Engineering Research Center (EERC) of the University of California, Berkeley. A primary purpose of these investigations is to obtain detailed information on the inelastic response mechanisms in typical structural systems so that the experimentally observed performance can be compared with computer generated analytical predictions. Only by such comparisons can the mathematical models used in dynamic nonlinear analyses be verified and improved. Two experimental procedures for investigating earthquake structural response are discussed: the earthquake simulator facility which subjects the base of the test structure to acceleration histories similar to those recorded in actual earthquakes, and systems of hydraulic rams which impose specified displacement histories on the test components, equivalent to motions developed in structures subjected to actual'quakes. The general concept and performance of the 20ft square EERC earthquake simulator is described, and the testing of a two story concrete frame building is outlined. Correlation of the experimental results with analytical predictions demonstrates that satisfactory agreement can be obtained only if the mathematical model incorporates a stiffness deterioration mechanism which simulates the cracking and other damage suffered by the structure

  19. Effectiveness and specificity of a classroom-based group intervention in children and adolescents exposed to war in Lebanon.

    Science.gov (United States)

    Karam, Elie G; Fayyad, John; Nasser Karam, Aimee; Cordahi Tabet, Caroline; Melhem, Nadine; Mneimneh, Zeina; Dimassi, Hani

    2008-01-01

    The purpose of this study was to examine the effectiveness and specificity of a classroom-based psychosocial intervention after war. All students (n=2500) of six villages in Southern Lebanon designated as most heavily exposed to war received a classroom-based intervention delivered by teachers, consisting of cognitive-behavioural and stress inoculation training strategies. A random sample of treated students (n=101) and a matched control group (n=93) were assessed one month post-war and one year later. Mental disorders and psychosocial stressors were assessed using the Diagnostic Interview for Children and Adolescents - Revised with children and parents. War exposure was measured using the War Events Questionnaire. The prevalence of major depressive disorder (MDD), separation anxiety disorder (SAD) and post-traumatic stress disorder (PTSD) was examined pre-war, one month post-war (pre-intervention), and one year post-war. Specificity of treatment was determined by rating teachers' therapy diaries. The rates of disorders peaked one month post-war and decreased over one year. There was no significant effect of the intervention on the rates of MDD, SAD or PTSD. Post-war MDD, SAD and PTSD were associated with pre-war SAD and PTSD, family violence parameters, financial problems and witnessing war events. These findings have significant policy and public health implications, given current practices of delivering universal interventions immediately post-war.

  20. Experimental studies of nonlinear beam dynamics

    International Nuclear Information System (INIS)

    Caussyn, D.D.; Ball, M.; Brabson, B.; Collins, J.; Curtis, S.A.; Derenchuck, V.; DuPlantis, D.; East, G.; Ellison, M.; Ellison, T.; Friesel, D.; Hamilton, B.; Jones, W.P.; Lamble, W.; Lee, S.Y.; Li, D.; Minty, M.G.; Sloan, T.; Xu, G.; Chao, A.W.; Ng, K.Y.; Tepikian, S.

    1992-01-01

    The nonlinear beam dynamics of transverse betatron oscillations were studied experimentally at the Indiana University Cyclotron Facility cooler ring. Motion in one dimension was measured for betatron tunes near the third, fourth, fifth, and seventh integer resonances. This motion is described by coupling between the transverse modes of motion and nonlinear field errors. The Hamiltonian for nonlinear particle motion near the third- and fourth-integer-resonance conditions has been deduced

  1. Magneto-Rheological Damper - An Experimental Study

    OpenAIRE

    Lozoya-Santos , Jorge De-Jesus; Morales-Menéndez , Rubén; Ramirez-Mendoza , Ricardo; Tudon-Martınez , Juan ,; Sename , Olivier; Dugard , Luc

    2012-01-01

    International audience; A Magneto-Rheological (MR) damper is evaluated under exhaustive experimental scenarios, generating a complete database. The obtained database includes classical tests and new proposals emphasizing the frequency contents. It also includes the impact of the electric current fluctuations. The variety of the performed experiments allows to study the MR damper force dynamics. A brief description of the damper behavior and a categorization of experiments based on driving con...

  2. Experimental Setups for Single Event Effect Studies

    OpenAIRE

    N. H. Medina; V. A. P. Aguiar; N. Added; F. Aguirre; E. L. A. Macchione; S. G. Alberton; M. A. G. Silveira; J. Benfica; F. Vargas; B. Porcher

    2016-01-01

    Experimental setups are being prepared to test and to qualify electronic devices regarding their tolerance to Single Event Effect (SEE). A multiple test setup and a new beam line developed especially for SEE studies at the São Paulo 8 UD Pelletron accelerator were prepared. This accelerator produces proton beams and heavy ion beams up to 107Ag. A Super conducting Linear accelerator, which is under construction, may fulfill all of the European Space Agency requirements to qualify electronic...

  3. Theoretical and experimental studies of elementary particles

    International Nuclear Information System (INIS)

    Bodek, A.; Ferbel, T.; Melissinos, A.C.; Olsen, S.L.; Slattery, P.; Tipton, P.; Das, A.; Hagen, C.R.; Rajeev, S.G.; Okubo, S.

    1991-01-01

    This report discusses: Fixed target experimentation at Fermilab; the D-zero collider experiment at Fermilab; deep inelastic lepton nucleon scattering; non-accelerator experiments and non-linear QED; the AMY experiment at TRISTAN and other activities at KEK; the collider detector at Fermilab; laser switched linac; preparations for experiments at the SSC; search for massive stable particles; and the Advanced Study Institute on techniques and concepts of high energy physics

  4. Experimental studies of gravitation and feebler forces

    International Nuclear Information System (INIS)

    Cowsik, R.

    1993-01-01

    The theoretical motivations and the experimental context pertaining to the recent experimental studies of the Weak equivalence Principle and the open-quotes Fifth Forceclose quotes are reviewed briefly. With such a backdrop, the innovative design and the technical details of the several new experiments in this area are presented with a special emphasis on the experiments underway at Gauribidanur, situated on the Deccan Plateau. These experiments jointly rule out the existence of any new forces coupling to baryon or lepton number with a coupling greater than about 10 -4 of gravitation per a.m.u. at ranges of about 0.5m and longer. In a few years the author hopes to test the weak equivalence principle with sensitivity exceeding 10 -13

  5. Experimental study of natural circulation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Wanderley F.; Su, Jian, E-mail: wlemos@lasme.coppe.ufrj.br, E-mail: sujian@lasme.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LASME/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Simulacao e Metodos Numericos; Faccini, Jose L.H., E-mail: faccini@ien.gov.br [Instituto de Engenharia Nuclear (LTE/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental

    2011-07-01

    This work presents an experimental study about fluid flows behavior in natural circulation, under conditions of single-phase flow. The experiment was performed through experimental thermal-hydraulic circuit built at IEN. This test equipment has performance similar to passive system of residual heat removal present in Advanced Pressurized Water Reactors (APWR). This experimental study aims to observing and analyzing the natural circulation phenomenon, using this experimental circuit that was dimensioned and built based on concepts of similarity and scale. This philosophy allows the analysis of natural circulation behavior in single-phase flow conditions proportionally to the functioning real conditions of a nuclear reactor. The experiment was performed through procedures to initialization of hydraulic feeding of primary and secondary circuits and electrical energizing of resistors installed inside heater. Power controller has availability to adjust values of electrical power to feeding resistors, in order to portray several conditions of energy decay of nuclear reactor in a steady state. Data acquisition system allows the measurement and monitoring of the evolution of the temperature in various points through thermocouples installed in strategic points along hydraulic circuit. The behavior of the natural circulation phenomenon was monitored by graphical interface on computer screen, showing the temperature evolutions of measuring points and results stored in digital spreadsheets. The results stored in digital spreadsheets allowed the getting of data to graphic construction and discussion about natural circulation phenomenon. Finally, the calculus of Reynolds number allowed the establishment for a correlation of friction in function of geometric scales of length, heights and cross section of tubing, considering a natural circulation flow throughout in the region of hot leg. (author)

  6. Experimental study of natural circulation circuit

    International Nuclear Information System (INIS)

    Lemos, Wanderley F.; Su, Jian; Faccini, Jose L.H.

    2011-01-01

    This work presents an experimental study about fluid flows behavior in natural circulation, under conditions of single-phase flow. The experiment was performed through experimental thermal-hydraulic circuit built at IEN. This test equipment has performance similar to passive system of residual heat removal present in Advanced Pressurized Water Reactors (APWR). This experimental study aims to observing and analyzing the natural circulation phenomenon, using this experimental circuit that was dimensioned and built based on concepts of similarity and scale. This philosophy allows the analysis of natural circulation behavior in single-phase flow conditions proportionally to the functioning real conditions of a nuclear reactor. The experiment was performed through procedures to initialization of hydraulic feeding of primary and secondary circuits and electrical energizing of resistors installed inside heater. Power controller has availability to adjust values of electrical power to feeding resistors, in order to portray several conditions of energy decay of nuclear reactor in a steady state. Data acquisition system allows the measurement and monitoring of the evolution of the temperature in various points through thermocouples installed in strategic points along hydraulic circuit. The behavior of the natural circulation phenomenon was monitored by graphical interface on computer screen, showing the temperature evolutions of measuring points and results stored in digital spreadsheets. The results stored in digital spreadsheets allowed the getting of data to graphic construction and discussion about natural circulation phenomenon. Finally, the calculus of Reynolds number allowed the establishment for a correlation of friction in function of geometric scales of length, heights and cross section of tubing, considering a natural circulation flow throughout in the region of hot leg. (author)

  7. Fluorene: An extended experimental thermodynamic study

    International Nuclear Information System (INIS)

    Monte, Manuel J.S.; Pinto, Sónia P.; Lobo Ferreira, Ana I.M.C.; Amaral, Luísa M.P.F.; Freitas, Vera L.S.; Ribeiro da Silva, Maria D.M.C.

    2012-01-01

    Highlights: ► Experimental results of an extended thermodynamic study on fluorene are presented. ► Enthalpy of combustion and vapor pressures of liquid and crystalline phase were measured. ► Enthalpy of sublimation was derived from three different experimental methods. ► New values of enthalpies of sublimation and of formation of fluorene are recommended. - Abstract: This work reports new experimental thermodynamic results on fluorene. Vapor pressures of both crystalline and liquid phases were measured using a pressure gauge (capacitance diaphragm manometer) and Knudsen effusion methods over a wide temperature range (292.20 to 412.16) K yielding accurate determination of enthalpy and entropy of sublimation and of vaporization. The enthalpy of sublimation was also determined using Calvet microcalorimetry. The enthalpy of fusion was derived from vapor pressure results and from d.s.c. experiments. Static bomb calorimetry was used to determine the enthalpy of combustion of fluorene from which the standard enthalpy of formation in the crystalline phase was calculated. The enthalpy of formation in the gaseous phase was calculated combining the result derived for the crystalline phase with the enthalpy of sublimation.

  8. Experimental percolation studies of random networks

    Science.gov (United States)

    Feinerman, A.; Weddell, J.

    2017-06-01

    This report establishes an experimental method of studying electrically percolating networks at a higher resolution than previously implemented. This method measures the current across a conductive sheet as a function of time as elliptical pores are cut into the sheet. This is done utilizing a Universal Laser System X2-600 100 W CO2 laser system with a 76 × 46 cm2 field and 394 dpc (dots/cm) resolution. This laser can cut a random system of elliptical pores into a conductive sheet with a potential voltage applied across it and measures the current versus time. This allows for experimental verification of a percolation threshold as a function of the ellipse's aspect ratio (minor/major diameter). We show that as an ellipse's aspect ratio approaches zero, the percolation threshold approaches one. The benefit of this method is that it can experimentally measure the effect of removing small pores, as well as pores with complex geometries, such as an asterisk from a conductive sheet.

  9. The Inequivalence of an Online and Classroom Based General Psychology Course

    Science.gov (United States)

    Edmonds, Christopher L.

    2006-01-01

    One-hundred seventy-five students enrolled in either a traditional classroom lecture section of General Psychology or in an online section of the same course were compared on exam performance. When covariates of high school grade point average and SAT composite scores were entered into the analysis, students enrolled in the classroom based lecture…

  10. A Classroom-Based Assessment Method to Test Speaking Skills in English for Specific Purposes

    Science.gov (United States)

    Alberola Colomar, María Pilar

    2014-01-01

    This article presents and analyses a classroom-based assessment method to test students' speaking skills in a variety of professional settings in tourism. The assessment system has been implemented in the Communication in English for Tourism course, as part of the Tourism Management degree programme, at Florida Universitaria (affiliated to the…

  11. More explicit communication after classroom-based crew resource management training: results of a pragmatic trial.

    NARCIS (Netherlands)

    Verbeek-van Noord, I.; Bruijne, M.C. de; Twisk, J.W.R.; Dyck, C. van; Wagner, C.

    2015-01-01

    Rationale, aims and objectives: Aviation-based crew resource management trainings to optimize non-technical skills among professionals are often suggested for health care as a way to increase patient safety. Our aim was to evaluate the effect of a 2-day classroom-based crew resource management (CRM)

  12. More explicit communication after classroom-based crew resource management training: results of a pragmatic trial

    NARCIS (Netherlands)

    van Noord, I.; de Bruijne, M.C.; Twisk, J.W.R.; van Dyck, C.; Wagner, C.

    2015-01-01

    Rationale, aims and objectives Aviation-based crew resource management trainings to optimize non-technical skills among professionals are often suggested for health care as a way to increase patient safety. Our aim was to evaluate the effect of a 2-day classroom-based crew resource management (CRM)

  13. Speech-Language Pathologists' and Teachers' Perceptions of Classroom-Based Interventions.

    Science.gov (United States)

    Beck, Ann R.; Dennis, Marcia

    1997-01-01

    Speech-language pathologists (N=21) and teachers (N=54) were surveyed regarding their perceptions of classroom-based interventions. The two groups agreed about the primary advantages and disadvantages of most interventions, the primary areas of difference being classroom management and ease of data collection. Other findings indicated few…

  14. Supporting First-Generation College Students through Classroom-Based Practices. Issue Brief

    Science.gov (United States)

    Institute for Higher Education Policy, 2012

    2012-01-01

    This report, which was commissioned as part of the Institute for Higher Education Policy's Walmart Minority Student Success Initiative, seeks to highlight how specific institutional policies and faculty-driven, classroom-based practices at Minority-Serving Institutions (MSIs) can change in an effort to better support the academic and social…

  15. Wines: water inelastic neutron scattering experimental study

    International Nuclear Information System (INIS)

    Risch, P.; Ait Abderrahim, H.; D'hondt, P.; Malabu, E.

    1997-01-01

    An intercomparison of calculated fast neutron flux (E > 1 MeV) traverse through a very thick water zone obtained using both S N , (DORT) and Monte-Carlo (TRIPOLI and MCBEND) codes in combination with different cross-sections libraries (based on ENDF/B-III, IV, V and VI), showed small discrepancies either between S N , and Monte-Carlo results or even between S N , or Monte-Carlo results when we consider different cross-sections libraries except for S N , calculation when using P 0 , cross-sections. In order to validate our calculations we looked for experimental data. Unfortunately no experiment, dedicated for the fast neutron transport in large thickness of water, was found in the literature. Therefore SCK-CEN and EDF decided to launch the WINES experiment which is dedicated to study this phenomenon. WINES sands for Water Inelastic Neutron scattering Experimental Study. The aim of this experiment is to provide-experimental data for validation of neutron transport codes and nuclear cross-sections libraries used for LWR surveillance dosimetry analysis. The experimental device is made of 1 m 3 cubic plexiglass container filled with demineralized water. At one face of this cube, a 235 U neutron fission source system is screwed. The source device is made of a 235 U (93 % weight enriched) 18.55 x 16 cm 2 plate cladded with aluminium which is inserted in neutron beam emerging from the graphite gas-cooled BR1 reactor. Fission chambers ( 238 U(n,f), 232 Th(n,f), 237 Np(n,f) and 235 U(n,f)) are used to measure the flux traverses on the central axis of the water cube perpendicular to the fission sources. In this paper we will compare the experimental data to the calculated results using the S N , transport code DORT with the P 3 , ELXSIR library, based on ENDF/B-V, and the P 7 -BUGLE-93 library, based on ENDF/B-VI as well as the Monte-Carlo transport code TRIPOLI with a cross-section library based on ENDF/B IV and ENDF/B-VI. (authors)

  16. Situated teaching improves empathy learning of the students in a BSN program: A quasi-experimental study.

    Science.gov (United States)

    Lee, Kwo-Chen; Yu, Chin-Ching; Hsieh, Pei-Ling; Li, Chin-Ching; Chao, Yann-Fen C

    2018-05-01

    Empathy is an important clinical skill for nursing students, but it is a characteristic difficult to teach and assess. To evaluate the effect of situated teaching on empathy learning among undergraduate nursing students. A cohort study with pre-post-test quasi-experimental design. The 2nd-year students were enrolled from two BSN programs. The teaching program was completed over 4 months on the basis of experiential learning theory which integrated the following four elements: classroom-based role play, self-reflection, situated learning and acting. The Jefferson Scale of Empathy-Health Profession-Student version was administered before and after the program. Objective Structure Clinical Examination (OSCE) was administered at the end of program and a rubrics scale was used to measure empathy. A generalized estimation equation was used to identify the effect of subjective empathy, and an independent t-test was used for the objective assessment between two groups. A total of 103 students were enrolled. The results showed that subjective empathy increased significantly in experimental group. In the Objective Structured Clinical Examination, examiners and standard patients gave significantly higher empathy scores to the situated teaching group than the control group. The present study indicated that situated teaching can improve empathy learning of the nursing students. However different methods of assessment of empathy produce different results. We therefore recommend that multiple measurements from difference perspectives are preferable in the assessment of empathy. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Classroom-based and distance learning education and training courses in end-of-life care for health and social care staff: a systematic review.

    Science.gov (United States)

    Pulsford, David; Jackson, Georgina; O'Brien, Terri; Yates, Sue; Duxbury, Joy

    2013-03-01

    Staff from a range of health and social care professions report deficits in their knowledge and skills when providing end-of-life and palliative care, and education and training has been advocated at a range of levels. To review the literature related to classroom-based and distance learning education and training initiatives for health and social care staff in end-of-life and palliative care, in terms of their target audience, extent, modes of delivery, content and teaching and learning strategies, and to identify the most effective educational strategies for enhancing care. A systematic review of the literature evaluating classroom-based and distance learning education and training courses for health and social care staff in end-of-life and palliative care. Online databases CINAHL, MEDLINE, EMBASE and PSYCHINFO between January 2000 and July 2010. Studies were selected that discussed specific education and training initiatives and included pre-and post-test evaluation of participants' learning. 30 studies met eligibility criteria. The majority reported successful outcomes, though there were some exceptions. Level of prior experience and availability of practice reinforcement influenced learning. Participative and interactive learning strategies were predominantly used along with discussion of case scenarios. Multi-professional learning was infrequently reported and service user and carer input to curriculum development and delivery was reported in only one study. Classroom-based education and training is useful for enhancing professionals' skills and perceived preparedness for delivering end-of-life care but should be reinforced by actual practice experience.

  18. Experimental Study of Dust Grain Charging

    Science.gov (United States)

    Spann, James F; Venturini, Catherine C.; Comfort, Richard H.; Mian, Abbas M.

    1999-01-01

    The results of an experimental study of the charging mechanisms of micron size dust grains are presented. Individual dust grains are electrodynamically suspended and exposed to an electron beam of known energy and flux, and to far ultraviolet radiation of known wavelength and intensity. Changes in the charge-to-mass ratio of the grain are directly measured as a function of incident beam (electron and/or photon), grain size and composition. Comparisons of our results to theoretical models that predict the grain response are presented.

  19. An experimental study of dislocation loop nucleation

    International Nuclear Information System (INIS)

    Bounaud, J.Y.; Leteurtre, J.

    1975-01-01

    The nucleation of dislocation loops is experimentally studied by observing the demixion of the Burgers vectors of dislocation loops nucleated in copper whiskers irradiated in flexion by fission fragments at room temperature. The demixion of Burgers vectors is observed by the dimensional effects of dislocation loops: after irradiation, the applied stress is removed; the whisker shows a residual strain that is due to loops because, after an annealing treatment to evaporate dislocation loops, each whisker recovers its initial straight shape. Everywhere along the whisker, the radius of curvature is measured and plotted vs the max. applied stress. Estimations of the interstitial and vacancy dislocation loop nuclei are derived [fr

  20. Clinical and experimental studies on radiation proctitis

    International Nuclear Information System (INIS)

    Honke, Yoshifumi

    1988-01-01

    Clinical and experimental studies were performed to clarify the mechanism of developing radiation proctitis. The results were as follows; (1) In the clinical study with 38 uterine cervix cancer patients, who received radiotherapy, diarrhea was observed in 44.7% at the acute stage, while rectal bleeding in 36.7% about 1 year after radiation. However, no clinical correlation was observed between diarrhea and rectal bleeding. (2) Colon fiberscopic examination revealed little change at the acute stage. However, erosion, ulcer and remarkable redness were found at the late stage. By the magnified fiberscope, unit degeneration was found in 72.8% at the acute stage. (3) Concerning the histopathological changes, edema and inflammatory change were observed immediately after irradiation. Fibrosis was observed in 83.3% at the late stage. (4) The number of the immunoglobulin containing cells decreased by radiation. However, its recovered as time passed after radiation. (5) In experimental study with rats by microangiography, there were ramarkable changes of the small vessels, such as bending, tortuosity and capillary hyperplasia at the acute stage. However, these changes returned to normal soon. At the late stage, decreased number of blood vessels were observed. The above results indicated that rectal bleeding after exposure to radiation are developed by secondary circulation abnormality caused by fibrosis of the perivascular tissues. (author) 52 refs

  1. Experimental study of rf pulsed heating

    CERN Document Server

    Laurent, L; Nantista, C; Dolgashev, V; Higashi, Y; Aicheler, M; Tantawi, S; Wuensch, W

    2011-01-01

    Cyclic thermal stresses produced by rf pulsed heating can be the limiting factor on the attainable reliable gradients for room temperature linear accelerators. This is especially true for structures that have complicated features for wakefield damping. These limits could be pushed higher by using special types of copper, copper alloys, or other conducting metals in constructing partial or complete accelerator structures. Here we present an experimental study aimed at determining the potential of these materials for tolerating cyclic thermal fatigue due to rf magnetic fields. A special cavity that has no electric field on the surface was employed in these studies. The cavity shape concentrates the magnetic field on one flat surface where the test material is placed. The materials tested in this study have included oxygen free electronic grade copper, copper zirconium, copper chromium, hot isostatically pressed copper, single crystal copper, electroplated copper, Glidcop (R), copper silver, and silver plated co...

  2. Laparoscopic ureterocalicostomy in pigs - experimental study

    Directory of Open Access Journals (Sweden)

    Paulo Fernando de Oliveira Caldas

    2015-07-01

    Full Text Available This study aimed to evaluated laparoscopic ureterocalicostomy as treatment of experimental ureteropelvic junction (UPJ obstruction in pigs. Ten male Large White pigs weighting approximately 28.4 (±1.43 kg were used in the current study. The UPJ obstruction was created laparoscopically by double-clipping of the left ureter. After 14 days the animals underwent laparoscopic ureterocalicostomy f The animals were sacrificed for subsequent retrograde pyelography in order to assess the anastomotic patency on the 28th day. The laparoscopic procedure for experimental obstruction of UPJ was successfully performed in all animals, as well as the laparoscopic ureterocalicostomy. There was intestinal iatrogenic injury in one animal. Satisfactory UPJ patency was noted in 75% of the animals. There was no stenosis of the proximal anastomosis between the ureter and the lower pole of the kidney in 37.5%, mild stenosis in 37.5% and severe stenosis in 25% of the animals. The laparoscopic approach for reestablishment he urinary flow by ureterocalicostomy was feasible in the porcine model. The ascending pyelography revealed satisfactory results of the laparoscopic ureterocalicostomy

  3. Experimental study of unsteady thermally stratified flow

    International Nuclear Information System (INIS)

    Lee, Sang Jun; Chung, Myung Kyoon

    1985-01-01

    Unsteady thermally stratified flow caused by two-dimensional surface discharge of warm water into a oblong channel was investigated. Experimental study was focused on the rapidly developing thermal diffusion at small Richardson number. The basic objectives were to study the interfacial mixing between a flowing layer of warm water and an underlying body of cold water and to accumulate experimental data to test computational turbulence models. Mean velocity field measurements were carried out by using NMR-CT(Nuclear Magnetic Resonance-Computerized Tomography). It detects quantitative flow image of any desired section in any direction of flow in short time. Results show that at small Richardson number warm layer rapidly penetrates into the cold layer because of strong turbulent mixing and instability between the two layers. It is found that the transfer of heat across the interface is more vigorous than that of momentum. It is also proved that the NMR-CT technique is a very valuable tool to measure unsteady three dimensional flow field. (Author)

  4. Vascularized nerve grafts: an experimental study.

    Science.gov (United States)

    Donzelli, Renato; Capone, Crescenzo; Sgulò, Francesco Giovanni; Mariniello, Giuseppe; Maiuri, Francesco

    2016-08-01

    The aim of this study is to define an experimental model in order to promote the functional recovery of the nerves using grafts with vascular support (Vascular Nerve Grafts - VNG). The aim of this study is to define, on an experimental model in normal recipient bed, whether the functional recovery with VNG is superior to that obtained non-vascularized graft (NNG). Twenty male rabbits, which underwent dissection of sciatic nerve, were later treated by reinnervation through an autograft. In 10 animals the reconstruction of sciatic nerve was realized with VNG; in 10 control animals the reconstruction of sciatic nerve was realized with NNG. The VNG group showed a better axonal organization and a significantly higher number of regenerated axons in the early phases (after 30 days) than the NNG group, whereas the difference in the axonal number at day 90 was less significant; besides, the axon diameter and the myelin thickness were not significantly improved by VNG group. Our data suggests that the use of VNG leads to a faster regeneration process and a better functional recovery, although the final results are comparable to those of the NNG. VNG improve the quality of the axonal regeneration (axonal diameter and Schwann cells), although the increase in the axonal number is not significant and does not improve the long-term functional outcome.

  5. Rationale and design of a randomized controlled trial examining the effect of classroom-based physical activity on math achievement

    Directory of Open Access Journals (Sweden)

    Mona Have

    2016-04-01

    Full Text Available Abstract Background Integration of physical activity (PA into the classroom may be an effective way of promoting the learning and academic achievement of children at elementary school. This paper describes the research design and methodology of an intervention study examining the effect of classroom-based PA on mathematical achievement, creativity, executive function, body mass index and aerobic fitness. Methods The study was designed as a school-based cluster-randomized controlled trial targeting schoolchildren in 1st grade, and was carried out between August 2012 and June 2013. Eligible schools in two municipalities in the Region of Southern Denmark were invited to participate in the study. After stratification by municipality, twelve schools were randomized to either an intervention group or a control group, comprising a total of 505 children with mean age 7.2 ± 0.3 years. The intervention was a 9-month classroom-based PA program that involved integration of PA into the math lessons delivered by the schools’ math teachers. The primary study outcome was change in math achievement, measured by a 45-minute standardized math test. Secondary outcomes were change in executive function (using a modified Eriksen flanker task and the Behavior Rating Inventory of Executive Function (BRIEF questionnaire filled out by the parents, creativity (using the Torrance Tests of Creative Thinking, TTCT, aerobic fitness (by the Andersen intermittent shuttle-run test and body mass index. PA during math lessons and total PA (including time spent outside school were assessed using accelerometry. Math teachers used Short Message Service (SMS-tracking to report on compliance with the PA intervention and on their motivation for implementing PA in math lessons. Parents used SMS-tracking to register their children’s PA behavior in leisure time. Discussion The results of this randomized controlled trial are expected to provide schools and policy-makers with

  6. Rationale and design of a randomized controlled trial examining the effect of classroom-based physical activity on math achievement.

    Science.gov (United States)

    Have, Mona; Nielsen, Jacob Have; Gejl, Anne Kær; Thomsen Ernst, Martin; Fredens, Kjeld; Støckel, Jan Toftegaard; Wedderkopp, Niels; Domazet, Sidsel Louise; Gudex, Claire; Grøntved, Anders; Kristensen, Peter Lund

    2016-04-11

    Integration of physical activity (PA) into the classroom may be an effective way of promoting the learning and academic achievement of children at elementary school. This paper describes the research design and methodology of an intervention study examining the effect of classroom-based PA on mathematical achievement, creativity, executive function, body mass index and aerobic fitness. The study was designed as a school-based cluster-randomized controlled trial targeting schoolchildren in 1st grade, and was carried out between August 2012 and June 2013. Eligible schools in two municipalities in the Region of Southern Denmark were invited to participate in the study. After stratification by municipality, twelve schools were randomized to either an intervention group or a control group, comprising a total of 505 children with mean age 7.2 ± 0.3 years. The intervention was a 9-month classroom-based PA program that involved integration of PA into the math lessons delivered by the schools' math teachers. The primary study outcome was change in math achievement, measured by a 45-minute standardized math test. Secondary outcomes were change in executive function (using a modified Eriksen flanker task and the Behavior Rating Inventory of Executive Function (BRIEF) questionnaire filled out by the parents), creativity (using the Torrance Tests of Creative Thinking, TTCT), aerobic fitness (by the Andersen intermittent shuttle-run test) and body mass index. PA during math lessons and total PA (including time spent outside school) were assessed using accelerometry. Math teachers used Short Message Service (SMS)-tracking to report on compliance with the PA intervention and on their motivation for implementing PA in math lessons. Parents used SMS-tracking to register their children's PA behavior in leisure time. The results of this randomized controlled trial are expected to provide schools and policy-makers with significant new insights into the potential of classroom-based

  7. Predicting Teacher Participation in a Classroom-Based, Integrated Preventive Intervention for Preschoolers.

    Science.gov (United States)

    Baker, Courtney N; Kupersmidt, Janis B; Voegler-Lee, Mary Ellen; Arnold, David H; Willoughby, Michael T

    2010-01-01

    Preschools provide a promising setting in which to conduct preventive interventions for childhood problems, but classroom programs can only be effective if teachers are willing and able to implement them. This study is one of the first to investigate predictors of the frequency of teacher participation in a classroom-based, randomized controlled trial of an integrated prevention program for preschoolers. The intervention was designed to promote school readiness with an integrated social and academic program, to be implemented by teachers with the support of classroom consultants. The current study is part of a larger project conducted with Head Start and community child care centers that serve primarily economically disadvantaged families; 49 teachers from 30 centers participated in this study. Overall, teachers conducted approximately 70% of the program activities. Participation decreased significantly over time from the first to the final week of the intervention, and also decreased within each week of the intervention, from the first to the final weekly activity. Teachers working at community child care centers implemented more intervention activities than did Head Start teachers. Teacher concerns about the intervention, assessed prior to training, predicted less participation. In addition, teachers' participation was positively related to their perception that their centers and directors were supportive, collegial, efficient, and fair, as well as their job satisfaction and commitment. Teacher experience, education, ethnicity, and self-efficacy were not significantly related to participation. In multi-level models that considered center as a level of analysis, substantial variance was accounted for by centers, pointing to the importance of considering center-level predictors in future research.

  8. Experimental studies of the magnetized friction force

    International Nuclear Information System (INIS)

    Fedotov, A. V.; Litvinenko, V. N.; Gaalnander, B.; Lofnes, T.; Ziemann, V.; Sidorin, A.; Smirnov, A.

    2006-01-01

    High-energy electron cooling, presently considered as an essential tool for several applications in high-energy and nuclear physics, requires an accurate description of the friction force which ions experience by passing through an electron beam. Present low-energy electron coolers can be used for a detailed study of the friction force. In addition, parameters of a low-energy cooler can be chosen in a manner to reproduce regimes expected in future high-energy operation. Here, we report a set of dedicated experiments in CELSIUS aimed at a detailed study of the magnetized friction force. Some results of the accurate comparison of experimental data with the friction force formulas are presented

  9. Granular Silo collapse: an experimental study

    Science.gov (United States)

    Clement, Eric; Gutierriez, Gustavo; Boltenhagen, Philippe; Lanuza, Jose

    2008-03-01

    We present an experimental work that develop some basic insight into the pre-buckling behavior and the buckling transition toward plastic collapse of a granular silo. We study different patterns of deformation generated on thin paper cylindrical shells during granular discharge. We study the collapse threshold for different bed height, flow rates and grain sizes. We compare the patterns that appear during the discharge of spherical beads, with those obtained in the axially compressed cylindrical shells. When the height of the granular column is close to the collapse threshold, we describe a ladder like pattern that rises around the cylinder surface in a spiral path of diamond shaped localizations, and develops into a plastic collapsing fold that grows around the collapsing silo.

  10. Exploring the role of classroom-based learning in professional identity formation of family practice residents using the experiences, trajectories, and reifications framework.

    Science.gov (United States)

    Chen, Luke Y C; Hubinette, Maria M

    2017-08-01

    Classroom-based learning such as academic half day has undervalued social aspects. We sought to explore its role in the professional identity development of family medicine residents. In this case study, residents and faculty from four training sites in the University of British Columbia Department of Family Practice were interviewed. The "experiences, trajectories, and reifications (ETR) framework" was used as a sensitizing tool for modified inductive (thematic) analysis of the transcripts. Classroom-based learning provided a different context for residents' interpretation of their clinical experiences, characterized as a "home base" for rotating urban residents, and a connection to a larger academic community for residents in rural training sites. Both these aspects were important in creating a positive trajectory of professional identity formation. Teaching directed at the learning needs of family physicians, and participation of family practice faculty as teachers and role models was a precipitation of a curriculum "centered in family medicine." Interactions between family medicine residents and faculty in the classroom facilitated the necessary engagements to reify a shared understanding of the discipline of family practice. Classroom-based learning has substantial impact on professional identity formation at an individual and collective level.

  11. Experimental study on low pressure flow instability

    International Nuclear Information System (INIS)

    Jiang Shengyao; Wu Xinxin; Wu Shaorong; Bo Jinhai; Zhang Youjie

    1997-05-01

    The experiment was performed on the test loop (HRTL-5), which simulates the geometry and system design of the 5 MW reactor. The flow behavior for a wide range of inlet subcooling, in which the flow undergoes from single phase to two phase, is described in a natural circulation system at low pressure (p = 0.1, 0.24 MPa). Several kinds of flow instability, e.g. subcooled boiling instability, subcooled boiling induced flashing instability, pure flashing instability as well as flashing coupled density wave instability and high frequency flow oscillation, are investigated. The mechanism of flashing and flashing concerned flow instability, which has never been studied well in this field, is especially interpreted. The experimental results show that, firstly, for a low pressure natural circulation system the two phase flow is unstable in most of inlet subcooling conditions, the two phase stable flow can only be reached at very low inlet subcooling; secondly, at high inlet subcooling the flow instability is dominated by subcooled boiling in the heated section, and at middle inlet subcooling is dominated by void flashing in the adiabatic long riser; thirdly, in two phase stable flow region the condition for boiling out of the core, namely, single phase flow in the heated section, two phase flow in the riser due to vapor flashing, can be realized. The experimental results are very important for the design and accident analysis of the vessel and swimming pool type natural circulation nuclear heating reactor. (7 refs., 10 figs., 1 tab.)

  12. Metabolic Desynchronization in Critical Conditions: Experimental Study

    Directory of Open Access Journals (Sweden)

    G. V. Livanov

    2006-01-01

    Full Text Available Objective. To conduct an experimental study of the impact of the time of administration of succinic acid preparations on central nervous system (CNS function and gas exchange while simulating metabolic therapy for severe poisoning by ethyl alcohol. The study was performed on 74 male albino rats weighing 140—180 g. Acute severe and very severe intoxication was simulated, by intraabdominally administering 30% ethanol to the rats. Cytoflavin was used to simulate experimental therapy. The rate of gas exchange was estimated by the oxygen uptake determined by the closed chamber method in a Regnault apparatus (Germany. Spontaneous bioelectrical activity was recorded in the frontooccipital lead by the routine procedure. External pain stimulation and rhythmical photostimulation were employed to evaluate cerebral responsiveness. Heterodirectional EEG changes in the «early» and «late» administration of succinate were not followed by the similar alterations of gas exchange: oxygen consumption in both the «early» and «late» administration of succinate remained significantly lower than in the control animals. With the late administration of succinate to the animals with mixed (toxic and hypoxic coma, the so-called discrepancy between the noticeably increased energy production and brutally diminished metabolism occurred. It may be just the pathological mechanism that was the basis for higher mortality in the late succinate administration group. The findings and their analysis make it possible to advance a hypothesis that succinate may cause metabolic desynchronization if activation of metabolic processes takes place under severe tissue respiratory tissue depression. In these cases, there is a severe damage to tissue and chiefly the brain. This manifests itself as EEG epileptiform activity splashes preceding the animals’ death. Therefore, resuscitation aimed at restoring the transport of oxygen and its involvement in tissue energy processes should

  13. Contribution to the experimental study of the hydraulic jump in ...

    African Journals Online (AJOL)

    The purpose of this study is to study experimentally the hydraulic jump evolving in a symmetric trapezoidal channel with a positive slope, requires the use of an experimental protocol, and to find experimental relations linking the characteristics of the formed projection. The experimental study investigated the variation of the ...

  14. Pulmonary emphysema induced by methylphenidate: experimental study.

    Science.gov (United States)

    Rapello, Gabriel Victor Guimarães; Antoniolli, Andréia; Pereira, Daniel Martins; Facco, Gilberto; Pêgo-Fernandes, Paulo Manuel; Pazetti, Rogério

    2015-01-01

    Methylphenidate is the most widely used drug for treating attention deficit hyperactivity disorder. However, it has important side effects, such as abdominal pain, insomnia, anorexia and loss of appetite, and also some cases of early severe emphysema after drug abuse have been reported. Our aim was to investigate the development of pulmonary emphysema in rats that were subjected to different doses of methylphenidate. Experimental study carried out at the laboratory of a public university. Eighteen male Wistar rats were divided into three groups: control (0.9% saline solution); MP 0.8 (methylphenidate, 0.8 mg/kg); MP 1.2 (methylphenidate, 1.2 mg/kg). After 90 days of daily gavage, the animals were sacrificed and lung tissue samples were prepared for analysis on the mean alveolar diameter (Lm). The Lm was greater in MP 0.8 (47.91 ± 3.13; P pulmonary emphysema.

  15. Experimental Study of Factors Affecting Soil Erodibility

    Science.gov (United States)

    Larionov, G. A.; Bushueva, O. G.; Gorobets, A. V.; Dobrovolskaya, N. G.; Kiryukhina, Z. P.; Krasnov, S. F.; Litvin, L. F.; Maksimova, I. A.; Sudnitsyn, I. I.

    2018-03-01

    The effect of different factors and preparation conditions of monofraction samples from the arable horizon of leached chernozem on soil erodibility and its relationship with soil tensile strength (STS) has been studied. The exposure of samples at 38°C reduces their erodibility by two orders of magnitude. The drying of samples, on the contrary, increases their erodibility. It has been shown that erodibility decreases during the experiment. It has been found that the inoculation of soil with yeast cultures ( Naganishia albida, Lipomyces tetrasporus) reliably increases the STS value in 1.5-1.9 times. The sterile soil is eroded more intensively than the unsterile soil: at 4.9 and 0.3 g/(m2 s), respectively. The drying of soil followed by wetting to the initial water content (30%) has no significant effect on the STS value in almost all experimental treatments.

  16. Experimental study of crossing angle collision

    International Nuclear Information System (INIS)

    Chen, T.; Rice, D.; Rubin, D.; Sagan, D.; Tigner, M.

    1993-01-01

    The non-linear coupling due to the beam-beam interaction with crossing angle has been studied. The major effect of a small (∼12mrad) crossing angle is to excite 5Q x ±Q s =integer coupling resonance family on large amplitude particles, which results in bad lifetime. On the CESR, a small crossing angle (∼2.4mr) was created at the IP and a reasonable beam-beam tune-shift was achieved. The decay rate of the beam is measured as a function of horizontal tune with and without crossing angle. The theoretical analysis, simulation and experimental measurements have a good agreement. The resonance strength as a function of crossing angle is also measured

  17. Experimental and theoretical study of reflux condensation

    Energy Technology Data Exchange (ETDEWEB)

    Bakke, Knut

    1997-12-31

    This thesis studies the separation of gas mixtures in a reflux condenser. also called a dephlegmator. Reflux condensation is separation of a gas mixture, in reflux flow with condensing liquid, under continuous heat removal. A numerical model of a dephlegmator for binary mixtures was developed. The model may readily be extended to multi-component mixtures, as the solution method is based on a matrix solver. Separation of a binary mixture in a reflux condenser test rig is demonstrated. The test facility contains a single-tube test section that was designed and built as part of the project. Test mixtures of propane and n-butane were used, and a total of 15 experiments are reported. Limited degree of separation was achieved due to limited heat transfer area and narrow boiling point range of the test mixture. The numerical model reproduces the experimental data within reasonable accuracy. Deviation between calculated and measured properties is less than 6% of the measured temperature and less than 5% of the measured flow rate. The model is based on mechanistic models of physical processes and is not calibrated or tuned to fit the experimental data. The numerical model is applied to a number of separation processes. These case studies show that the required heat transfer area increases rapidly with increments in top product composition (light component). Flooding limits the amount of reflux liquid. The dephlegmator is suitable for separation of feed mixtures that are rich in light components. The gliding temperature in the dephlegmation process enables utilization of top product as refrigerant, with subsequent energy saving as a result. 61 refs., 50 figs., 34 tabs.

  18. An experimental study of mixed convection

    International Nuclear Information System (INIS)

    Saez, Manuel

    1998-01-01

    The aim of our study is to establish a reliable data base for improving thermal-hydraulic codes, in the field of turbulent flows with buoyancy forces. The flow considered is mixed convection in the Reynolds and Richardson number range: Re=10"3 to 6*10"4 and Ri=10"-"4 to 1. Experiments are carried out in an upward turbulent flow between vertical parallel plates at different wall temperatures. Part 1 gives a detailed data base of turbulent mixed flow of free and forced convection. Part II presents the installation and the calibration system intended for probes calibration. Part III describes the measurement technique (constant-temperature probe and cold-wire probe) and the method for measuring the position of the hot-wire anemometer from the wall surface. The measurement accuracy is within 0.001 mm in the present system. Part IV relates the development of a method for near wall measurements. This correction procedure for hot-wire anemometer close to wall has been derived on the basis of a two-dimensional numerical study. The method permits to obtain a quantitative correction of the wall influence on hot-wires and takes into account the velocity profile and the effects the wall material has on the heat loss. Part V presents the experimental data obtained in the channel in forced and mixed convection. Results obtained in the forced convection regime serve as a verification of the measurement technique close to the wall and give the conditions at the entrance of the test section. The effects of the buoyancy force on the mean velocity and temperature profiles are confirmed. The buoyancy strongly affects the flow structure and deforms the distribution of mean velocity. The velocity profiles are asymmetric. The second section of part V gives an approach of analytical wall functions with buoyancy forces, on the basis of the experimental data obtained in the test section. (author) [fr

  19. Rationale and design of a randomized controlled trial examining the effect of classroom-based physical activity on math achievement

    DEFF Research Database (Denmark)

    Have, Mona; Nielsen, Jacob Have; Gejl, Anne Kær

    2016-01-01

    was a 9-month classroom-based PA program that involved integration of PA into the math lessons delivered by the schools' math teachers. The primary study outcome was change in math achievement, measured by a 45-minute standardized math test. Secondary outcomes were change in executive function (using...... a modified Eriksen flanker task and the Behavior Rating Inventory of Executive Function (BRIEF) questionnaire filled out by the parents), creativity (using the Torrance Tests of Creative Thinking, TTCT), aerobic fitness (by the Andersen intermittent shuttle-run test) and body mass index. PA during math...... lessons and total PA (including time spent outside school) were assessed using accelerometry. Math teachers used Short Message Service (SMS)-tracking to report on compliance with the PA intervention and on their motivation for implementing PA in math lessons. Parents used SMS-tracking to register...

  20. Experimental study of rf pulsed heating

    Directory of Open Access Journals (Sweden)

    Lisa Laurent

    2011-04-01

    Full Text Available Cyclic thermal stresses produced by rf pulsed heating can be the limiting factor on the attainable reliable gradients for room temperature linear accelerators. This is especially true for structures that have complicated features for wakefield damping. These limits could be pushed higher by using special types of copper, copper alloys, or other conducting metals in constructing partial or complete accelerator structures. Here we present an experimental study aimed at determining the potential of these materials for tolerating cyclic thermal fatigue due to rf magnetic fields. A special cavity that has no electric field on the surface was employed in these studies. The cavity shape concentrates the magnetic field on one flat surface where the test material is placed. The materials tested in this study have included oxygen free electronic grade copper, copper zirconium, copper chromium, hot isostatically pressed copper, single crystal copper, electroplated copper, Glidcop®, copper silver, and silver plated copper. The samples were exposed to different machining and heat treatment processes prior to rf processing. Each sample was tested to a peak pulsed heating temperature of approximately 110°C and remained at this temperature for approximately 10×10^{6} rf pulses. In general, the results showed the possibility of pushing the gradient limits due to pulsed heating fatigue by the use of copper zirconium and copper chromium alloys.

  1. Hot forming of composite prepreg : Experimental study

    Science.gov (United States)

    Tardif, Xavier; Duthille, Bertrand; Bechtel, Stephane; le Pinru, Louis; Campagne, Benjamin; Destombes, Gautier; Deshors, Antoine; Marchand, Christophe; Azzouzi, Khalid El; Moro, Tanguy

    2017-10-01

    The hot forming of thermoset prepreg consists in bending an uncured composite part by applying a mechanical constrain on the hot laminate. Most of the time, the mold is inserted in a vacuum box and the mechanical constrain is applied on the composite laminate by a single membrane or a double-membrane. But the performance improvement products resulted in forming increasingly complex parts with advanced materials having a less formability. These new complex parts require a finer comprehension of the process and an optimization of the key parameters to get acceptable quality. In this work, an experimental study has been carried out to identify the process conditions that do not lead to unacceptable defaults: undulations of fibers. In the present study, downward-bending has been evaluated with an original light mechanical forming concept, for a given stacking sequence. The influence of the part's temperature and the part's bending speed are investigated. To carry this study out, a hot forming test bench has been designed and manufactured to have a precise supervision of the process conditions. It is able to bend parts of 1500 mm length x 600 mm width x 20 mm thick.

  2. Theoretical and experimental studies of elementary physics

    International Nuclear Information System (INIS)

    Bodek, A.; Ferbel, T.; Melissinos, A.C.; Slattery, P.; Tipton, P.; Das, A.; Hagen, C.R.; Rajeev, S.G.; Okubo, S.; Orr, L.

    1993-01-01

    The various components of the high-energy physics research program at the University of Rochester are presented. (I)Fixed-target experimentation at FNAL includes studies of direct photon production by p and π on H, Be, and Cu, and hybrid mesons and other physics issues in Coulomb excitation at high energies. (II)The status of the GEM (Gammas, Electrons, and Muons) Experiment at the SSC is given. (III)The D-Zero experiment at FNAL is reviewed. (IV)Deep inelastic lepton--nucleon scattering experiments are summarized: electron scattering experiments at SLAC, FNAL neutrino quad triplet runs, FNAL neutrino sign selected experiments, and SDC cosmic ray test and test beam calibration. (V)Studies of nonlinear QED at SLAC concentrated on a study of QED at critical field strength in intense laser--high-energy electron collisions. (VI)Development work on the Collider Detector at Fermilab (CDF) emphasized the CDF silicon vertex detector, the end plug calorimeter, and the SDC tile/fiber calorimetry. (VII)The theoretical physics effort is sketched

  3. Experimental study on transient boiling heat transfer

    International Nuclear Information System (INIS)

    Visentini, R.

    2012-01-01

    Boiling phenomena can be found in the everyday life, thus a lot of studies are devoted to them, especially in steady state conditions. Transient boiling is less known but still interesting as it is involved in the nuclear safety prevention. In this context, the present work was supported by the French Institute of Nuclear Safety (IRSN). In fact, the IRSN wanted to clarify what happens during a Reactivity-initiated Accident (RIA). This accident occurs when the bars that control the nuclear reactions break down and a high power peak is passed from the nuclear fuel bar to the surrounding fluid. The temperature of the nuclear fuel bar wall increases and the fluid vaporises instantaneously. Previous studies on a fuel bar or on a metal tube heated by Joule effect were done in the past in order to understand the rapid boiling phenomena during a RIA. However, the measurements were not really accurate because the measurement techniques were not able to follow rapid phenomena. The main goal of this work was to create an experimental facility able to simulate the RIA boiling conditions but at small scale in order to better understand the boiling characteristics when the heated-wall temperature increases rapidly. Moreover, the experimental set-up was meant to be able to produce less-rapid transients as well, in order to give information on transient boiling in general. The facility was built at the Fluid-Mechanics Institute of Toulouse. The core consists of a metal half-cylinder heated by Joule effect, placed in a half-annulus section. The inner half cylinder is made of a 50 microns thick stainless steel foil. Its diameter is 8 mm, and its length 200 mm. The outer part is a 34 mm internal diameter glass half cylinder. The semi-annular section is filled with a coolant, named HFE7000. The configuration allows to work in similarity conditions. The heated part can be place inside a loop in order to study the flow effect. The fluid temperature influence is taken into account as

  4. Daylighting Design in Classroom Based on Yearly-Graphic Analysis

    Directory of Open Access Journals (Sweden)

    Yang Guan

    2016-07-01

    Full Text Available In China, existing buildings comprise more than 40 billion square meters, most being of high energy consumption. A substantial reduction in electrical energy costs could be obtained through greater use of daylight. Daylight varies widely due to the movement of sun, changing seasons and diverse weather conditions. Custom static daylight assessments, simulations represent only one time of the year or one time of the day, are inadequate to evaluate the dynamics of daylight variability. Using the intuitive graphic tool Temporal Map to display the annual daylight data, this study compared different passive architectural design strategies under the climate conditions of five representative Chinese cities and selected the most suitable design scheme for each city. In this study, the dynamic yearly-graphic tool was utilized for architectural design in China, and we integrated the optimal design with the Chinese academic calendar to achieve improvements within the occupancy time. This modified map connects design work with human activity that makes daylight evaluation more accurate and efficient. The results of this study will provide preliminary recommendations for energy-saving design in China, and reference to other similar studies.

  5. Bridging the Gap from Classroom-based Learning to Experiential Professional Learning: A Hong Kong Case

    OpenAIRE

    Bertha Du-Babcock

    2016-01-01

    This paper describes and evaluates a funded longitudinal teaching development project that aims to bridge the gap from classroom-based theory learning to experiential professional learning, and thereby prepare ideal and competent world class graduates. To align with the University's shared mission to foster links with the business community, the design of the internship program has a threefold purpose and was implemented in stages. It intends to enhance students' professional awareness-knowle...

  6. A Comparison of Web-Based with Traditional Classroom-Based Training of Lung Ultrasound for the Exclusion of Pneumothorax.

    Science.gov (United States)

    Edrich, Thomas; Stopfkuchen-Evans, Matthias; Scheiermann, Patrick; Heim, Markus; Chan, Wilma; Stone, Michael B; Dankl, Daniel; Aichner, Jonathan; Hinzmann, Dominik; Song, Pingping; Szabo, Ashley L; Frendl, Gyorgy; Vlassakov, Kamen; Varelmann, Dirk

    2016-07-01

    Lung ultrasound (LUS) is a well-established method that can exclude pneumothorax by demonstration of pleural sliding and the associated ultrasound artifacts. The positive diagnosis of pneumothorax is more difficult to obtain and relies on detection of the edge of a pneumothorax, called the "lung point." Yet, anesthesiologists are not widely taught these techniques, even though their patients are susceptible to pneumothorax either through trauma or as a result of central line placement or regional anesthesia techniques performed near the thorax. In anticipation of an increased training demand for LUS, efficient and scalable teaching methods should be developed. In this study, we compared the improvement in LUS skills after either Web-based or classroom-based training. We hypothesized that Web-based training would not be inferior to "traditional" classroom-based training beyond a noninferiority limit of 10% and that both would be superior to no training. Furthermore, we hypothesized that this short training session would lead to LUS skills that are similar to those of ultrasound-trained emergency medicine (EM) physicians. After a pretest, anesthesiologists from 4 academic teaching hospitals were randomized to Web-based (group Web), classroom-based (group class), or no training (group control) and then completed a posttest. Groups Web and class returned for a retention test 4 weeks later. All 3 tests were similar, testing both practical and theoretical knowledge. EM physicians (group EM) performed the pretest only. Teaching for group class consisted of a standardized PowerPoint lecture conforming to the Consensus Conference on LUS followed by hands-on training. Group Web received a narrated video of the same PowerPoint presentation, followed by an online demonstration of LUS that also instructs the viewer to perform an LUS on himself using a clinically available ultrasound machine and submit smartphone snapshots of the resulting images as part of a portfolio system

  7. Experimental study of finite Larmor radius effects

    International Nuclear Information System (INIS)

    Struve, K.W.

    1980-08-01

    Linear Z-pinches in Ar, Kr, Xe, N 2 , and He are experimentally studied in regimes where strong finite Larmor radius effects could provide a significant stabilizing effect. Scaling arguments show that for deuterium such a pinch has an electron line density of order 2 x 10 15 /cm. For higher Z plasmas a higher line density is allowed, the exact value of which depends on the average ion charge. The pinch is formed by puffing gas axially through the cathode towards the anode of an evacuated pinch chamber. When the gas reaches the anode, the pinch bank is fired. The pinch current rises in 2 to 3 μsec to a maximum of 100 to 200 kA. The pinch bank capacitance is 900 μF, and the external inductance is 100 nH. Additionally, the bank is fused to increase dI/dt. The primary diagnostics are a framing camera, a spatially resolved Mach-Zehnder interferometer, and X-ray absorption

  8. Experimental Study on Revetec Engine Cam Performance

    International Nuclear Information System (INIS)

    Gasim, Maisara Mohyeldin; Chui, Lee Giok; Anwar, Khirul Azhar bin

    2012-01-01

    In Revetec engine (three-lobed) cam replaces the crankshaft to convert the reciprocating motion of the engine piston, to a rotating motion in the drive line. Since the cam controls the piston movement, the cam profile has a great effect on engine performance. In this paper an experimental study was done to a (three- lobed) cam with Cycloidal motion profile but with different ratios between the base circle radius of the cam and the radius of the roller follower. DEWESoft was used to find the displacement and the vibration of the piston, and compare the actual results from the test with the theoretical results from the cam profile equation. The results showed that there is a periods of miss contact between the follower and the cam when the ratio between the base circle radius of the cam and the radius of the roller follower is less than a certain value, and also increasing of vibration. The suggested ratio between the cam and follower radius is to be more than 2:1.

  9. Experimental study of vapor bubble dynamics

    International Nuclear Information System (INIS)

    Pasquini, Maria-Elena

    2015-01-01

    The object of this thesis is an experimental study of vapor bubble dynamics in sub-cooled nucleate boiling. The test section is locally heated by focusing a laser beam: heat fluxes from 1 e4 to 1.5 e6 W/m 2 and water temperature between 100 and 88 C have been considered. Three boiling regimes have been observed. Under saturated conditions and with low heat fluxes a developed nucleate boiling regime has been observed. Under higher sub-cooling and still with low heat fluxes an equilibrium regime has been observed in which the liquid flowrate evaporating at the bubble base is compensated by the vapor condensing flowrate at bubble top. A third regime have been observed at high heat fluxes for all water conditions: it is characterized by the formation of a large dry spot on the heated surface that keeps the nucleation site dry after bubble detachment. The condensation phase starts after bubble detachment. Bubble equivalent radius at detachment varies between 1 and 2.5 mm. Bubble properties have been measured and non-dimensional groups have been used to characterize bubble dynamics. Capillary waves have been observed on the bubble surface thanks to high-speed images acquisition. Two main phenomena have been proposed to explain capillary waves effects on bubble condensation: increasing of the phases interface area and decreasing of vapor bubble translation velocity, because of the increased drag force on the deformed bubble. (author) [fr

  10. Experimental studies of fiber concrete creep

    Directory of Open Access Journals (Sweden)

    Korneeva Irina

    2017-01-01

    Full Text Available The results of two-stage experimental studies of the strength and deformation characteristics of fibrous concrete reinforced with steel fiber. In the experiments we used steel fiber with bent ends, which practically does not form "hedgehogs", which allows to achieve an even distribution of the fiber by volume. At the first stage, the cube and prismatic strength, deformability at central compression, a number of special characteristics are determined: water absorption, frost resistance, abrasion; the optimal percentage of fiber reinforcement and the maximum size of the coarse aggregate fraction were selected. Fiber reinforcement led to an increase in the strength of concrete at compression by 1,35 times and an increase in the tensile strength at bending by 3,4 times. At the second stage, the creep of fibrous concrete and plain concrete of similar composition at different stress levels was researched. Creep curves are plotted. It is shown that the use of fiber reinforcement leads to a decrease in creep strain by 21 to 30 percent, depending on the stress level.

  11. Experimental study of a spark-gap

    International Nuclear Information System (INIS)

    Bruzzone, H.; Moreno, C.; Vieytes, R.

    1990-01-01

    Some experimental results concerning to the resistance of an atmospheric pressure spark-gap, operating in the self breakdown regime are presented. The influence of the energy discharging through the gap on this resistance is discussed. (Author)

  12. Evapotranspiration studies for protective barriers: Experimental plans

    International Nuclear Information System (INIS)

    Link, S.O.; Waugh, W.J.

    1989-11-01

    This document describes a general theory and experimental plans for predicting evapotranspiration in support of the Protective Barrier Program. Evapotranspiration is the combined loss of water from plants and soil surfaces to the atmosphere. 45 refs., 1 fig., 4 tabs

  13. Experimental study of the pile EL3

    International Nuclear Information System (INIS)

    1958-01-01

    The results of two months' experiments, carried out at low power following the first divergence (4. July 1957) are presented. These experiments dealt with the following points: comparison of experimental and calculated values of the critical size; effects due to the introduction of absorbing materials into the principal experimental facilities, flux distribution measurements especially in these facilities, calibration of safety, control and compensating rods, determination of the average life of the neutrons. (author) [fr

  14. Experimental Study of Lunar and SNC Magmas

    Science.gov (United States)

    Rutherford, Malcolm J.

    1998-01-01

    The research described in this progress report involved the study of petrological, geochemical and volcanic processes that occur on the Moon and the SNC parent body, generally accepted to be Mars. The link between these studies is that they focus on two terrestrial-type parent bodies somewhat smaller than earth, and the fact that they focus on the role of volatiles in magmatic processes and on processes of magma evolution on these planets. The work on the lunar volcanic glasses has resulted in some exciting new discoveries over the years of this grant. We discovered small metal blebs initially in the Al5 green glass, and determined the significant importance of this metal in fixing the oxidation state of the parent magma (Fogel and Rutherford, 1995). More recently, we discovered a variety of metal blebs in the Al7 orange glass. Some of these Fe-Ni metal blebs were in the glass; others were in olivine phenocrysts. The importance of these metal spheres is that they fix the oxidation state of the parent magma during the eruption, and also indicate changes during the eruption (Weitz et al., 1997) They also yield important information about the composition of the gas phase present, the gas which drove the lunar fire-fountaining. One of the more exciting and controversial findings in our research over the past year has been the possible fractionation of H from D during shock (experimental) of hornblende bearing samples (Minitti et al., 1997). This research is directed at explaining some of the low H2O and high D/H observed in hydrous phases in the SNC meteorites.

  15. Experimental and computational studies of nanofluids

    Science.gov (United States)

    Vajjha, Ravikanth S.

    The goals of this dissertation were (i) to experimentally investigate the fluid dynamic and heat transfer performance of nanofluids in a circular tube, (ii) to study the influence of temperature and particle volumetric concentration of nanofluids on thermophysical properties, heat transfer and pumping power, (iii) to measure the rheological properties of various nanofluids and (iv) to investigate using a computational fluid dynamic (CFD) technique the performance of nanofluids in the flat tube of a radiator. Nanofluids are a new class of fluids prepared by dispersing nanoparticles with average sizes of less than 100 nm in traditional heat transfer fluids such as water, oil, ethylene glycol and propylene glycol. In cold regions of the world, the choice of base fluid for heat transfer applications is an ethylene glycol or propylene glycol mixed with water in different proportions. In the present research, a 60% ethylene glycol (EG) or propylene glycol (PG) and 40% water (W) by mass fluid mixture (60:40 EG/W or 60:40 PG/W) was used as a base fluid, which provides freeze protection to a very low level of temperature. Experiments were conducted to measure the convective heat transfer coefficient and pressure loss of nanofluids flowing in a circular tube in the fully developed turbulent regime. The experimental measurements were carried out for aluminum oxide (Al2O3), copper oxide (CuO) and silicon dioxide (SiO2) nanoparticles dispersed in 60:40 EG/W base fluid. Experiments revealed that the heat transfer coefficient of nanofluids showed an increase with the particle volumetric concentration. Pressure loss was also observed to increase with the nanoparticle volumetric concentration. New correlations for the Nusselt number and the friction factor were developed. The effects of temperature and particle volumetric concentration on different thermophysical properties (e.g. viscosity, thermal conductivity, specific heat and density) and subsequently on the Prandtl number

  16. Experimental microangiographic study in normal rabbit liver

    International Nuclear Information System (INIS)

    Kim, Yoon Gyoo; Park, Jong Yeon; Han, Kook Sang; Moon, Ki Ho; Choi, Chang Ho; Han, Koon Taek; Lee, Suck Hong; Kim, Byung Soo

    1994-01-01

    Microangiography is an experimental radiologic technique for evaluation of the morphology and the function of small vessels. The purpose of this study is to introduce a good microangiographic technique and to present the microangiographic appearance of normal hepatic vascular pattern. Five white rabbits weighing 2.5-2.9Kg were objected. Polyethylene catheters were inserted in portal vein and then in IVC. Heparin mixed normal saline (2cc/1000cc) was infused through portal vein and blood was drained to IVC. Barium suspension was infused via the catheter placed in portal vein until the liver surface showed satisfactory finding in barium filling. The liver was removed and this preparation was fixed in 10% formaline for 7 days. After fixation, the liver was sectioned on 1-2mm thickness. The slices were radiographed on high resolution plate using Faxitron. H-E staining of liver tissue was also done. The microbrium was well distributed in all small vessels without filling defect. And we could find the hexagonal shaped classic liver lobule, in which the central vein was located at central portion and portal vein at periphery. The enlargement was showed numerous sinusoids, but there was less dye in the central portion of lobule, but the central vein was well filled by microbarium. The peripheral portion of lobule was well filled with microbarium. So, we could find diamond shaped liver acinus, in which central vein was located at priperal portion and the center of liver acinus was terminal portal vein that growed out from a small portal space. The three acini made the complex acinus and acinar agglomerate was composed of three or four complex acini. It is considered that the liver acinus pattern of Rapparport is more acceptable on microangiography than the classic concept of hepatic lobule

  17. Experimental study and modelling of transient boiling

    International Nuclear Information System (INIS)

    Baudin, Nicolas

    2015-01-01

    A failure in the control system of the power of a nuclear reactor can lead to a Reactivity Initiated Accident in a nuclear power plant. Then, a power peak occurs in some fuel rods, high enough to lead to the coolant film boiling. It leads to an important increase of the temperature of the rod. The possible risk of the clad failure is a matter of interest for the Institut de Radioprotection et de Securite Nucleaire. The transient boiling heat transfer is not yet understood and modelled. An experimental set-up has been built at the Institut de Mecanique des Fluides de Toulouse (IMFT). Subcooled HFE-7000 flows vertically upward in a semi annulus test section. The inner half cylinder simulates the clad and is made of a stainless steel foil, heated by Joule effect. Its temperature is measured by an infrared camera, coupled with a high speed camera for the visualization of the flow topology. The whole boiling curve is studied in steady state and transient regimes: convection, onset of boiling, nucleate boiling, critical heat flux, film boiling and rewetting. The steady state heat transfers are well modelled by literature correlations. Models are suggested for the transient heat flux: the convection and nucleate boiling evolutions are self-similar during a power step. This observation allows to model more complex evolutions, as temperature ramps. The transient Hsu model well represents the onset of nucleate boiling. When the intensity of the power step increases, the film boiling begins at the same temperature but with an increasing heat flux. For power ramps, the critical heat flux decreases while the corresponding temperature increases with the heating rate. When the wall is heated, the film boiling heat transfer is higher than in steady state but it is not understood. A two-fluid model well simulates the cooling film boiling and the rewetting. (author)

  18. Water-clay interactions. Experimental study

    International Nuclear Information System (INIS)

    Gaucher, Eric

    1998-01-01

    Clay minerals contribute to the chemical composition of soil and sediment groundwaters via surface and dissolution/precipitation reactions. The understanding of those processes is still today fragmentary. In this context, our experimental purpose is to identify the contribution of each reaction in the chemical composition of water in a water/clay System. Kaolinite, illite, montmorillonite are the reference clays. After a fine mineralogical study, the exchange equilibria between K + and H + are characterised. Different exchange sites are identified and the exchange capacities and selectivity coefficients are quantified. Then, mixtures of the three clays are equilibrated with acidic and basic (I≤10 -2 M) solutions at 25 deg. C, 60 deg. C, 80 deg. C, during 320 days. The System evolution is observed by chemical analysis of the solutions and mineralogical analysis by TEM. We show that montmorillonite is unstable compared to the kaolinite/amorphous silica assemblage for solutions of pH<7. Aqueous silica is probably controlled by the kinetics of dissolution of the montmorillonite in moderate pH media. In more acidic solutions, amorphous silica precipitates. Al is under control of 'kaolinite' neo-formations. The use of the selectivity coefficients in a numerical simulation shows that K + concentration depends on exchange reactions. The pH has a more complicated evolution, which is not completely understood. This evolution depends on both exchange equilibria and organic acid occurrence. In this type of experiments, we have demonstrated that the equilibrium equations between smectite and kaolinite are inexact. The problem of the thermodynamic nature of clays remains and is not resolved by these solubility experiments. (author) [fr

  19. Solar pond conception - experimental and theoretical studies

    Energy Technology Data Exchange (ETDEWEB)

    Kurt, Huseyin [Zonguldak Karaelmas Univ., Technical Education Faculty, Karabuk (Turkey); Halici, Fethi [Sakarya Univ., Mechanical Engineering Dept., Adapazari (Turkey); Binark, A. Korhan [Marmara Univ., Technical Education Faculty, Istanbul (Turkey)

    2000-07-01

    A one dimensional transient mathematical model for predicting the thermal performance of the salt gradient solar pond is developed and presented. In this paper, the natural solar ponds and different artificial solar pond systems found in the literature are introduced. Necessary modifications are made on the experimental stand located in Istanbul Technical University, the experimental stand is introduced and natural phenomena produced in the pond by the different solar pond variations under natural conditions are observed. In the theoretical work based on a one dimensional unsteady state heat conduction model with internal heat generation, the energy and mass balance equations for the upper convective zone, the non-convective zone and the lower convective zone, all of which form the solar pond, are written in terms of differential equations. These equations are solved analytically and numerically. The results obtained from the analysis are compared with the experimental results. The temperature and the concentration profiles are separately presented in the figures. (Author)

  20. Biomass thermochemical gasification: Experimental studies and modeling

    Science.gov (United States)

    Kumar, Ajay

    The overall goals of this research were to study the biomass thermochemical gasification using experimental and modeling techniques, and to evaluate the cost of industrial gas production and combined heat and power generation. This dissertation includes an extensive review of progresses in biomass thermochemical gasification. Product gases from biomass gasification can be converted to biopower, biofuels and chemicals. However, for its viable commercial applications, the study summarizes the technical challenges in the gasification and downstream processing of product gas. Corn stover and dried distillers grains with solubles (DDGS), a non-fermentable byproduct of ethanol production, were used as the biomass feedstocks. One of the objectives was to determine selected physical and chemical properties of corn stover related to thermochemical conversion. The parameters of the reaction kinetics for weight loss were obtained. The next objective was to investigate the effects of temperature, steam to biomass ratio and equivalence ratio on gas composition and efficiencies. DDGS gasification was performed on a lab-scale fluidized-bed gasifier with steam and air as fluidizing and oxidizing agents. Increasing the temperature resulted in increases in hydrogen and methane contents and efficiencies. A model was developed to simulate the performance of a lab-scale gasifier using Aspen Plus(TM) software. Mass balance, energy balance and minimization of Gibbs free energy were applied for the gasification to determine the product gas composition. The final objective was to optimize the process by maximizing the net energy efficiency, and to estimate the cost of industrial gas, and combined heat and power (CHP) at a biomass feedrate of 2000 kg/h. The selling price of gas was estimated to be 11.49/GJ for corn stover, and 13.08/GJ for DDGS. For CHP generation, the electrical and net efficiencies were 37 and 86%, respectively for corn stover, and 34 and 78%, respectively for DDGS. For

  1. Experimental Study of a Thermoelectric Generation System

    DEFF Research Database (Denmark)

    Zhu, Junpeng; Gao, Junling; Chen, Min

    2011-01-01

    . System-level simulation is carried out using a quasi-one-dimensional numerical model that enables direct comparison with experimental results. The results of both experiment and simulation will provide a foundation to improve and optimize complex thermoelectric generation systems....

  2. Experimental methods to study tokamak plasma stability

    International Nuclear Information System (INIS)

    Perez-Navarro, A.

    1978-01-01

    Experimental devices to measure external instability modes with small pick-up coils to detect poloidal magnetic field fluctuations, and internal modes with soft-X-ray detectors are discussed. The characteristics of these devices are calculated for a small tokamak (R 0 = 30 cm, a = 10 cm, I 0 50 KA). (author)

  3. EXPERIMENTAL STUDY OF MAGNETIC FLUID SEAL

    Directory of Open Access Journals (Sweden)

    V. G. Bashtovoi

    2006-01-01

    Full Text Available Dependences of critical pressure drop, being held by magnetic fluid seal, on time in a static state and shaft rotation velocity in dynamics have been experimentally determined. The significant influence of particles’ redistribution in magnetic fluid on static parameters of magnetic fluid seal has been established.

  4. Blast mitigation experimental and numerical studies

    CERN Document Server

    2013-01-01

    Presents experimental methods of material and structural response to dynamic blast loads Includes computational analysis of material and structural response to dynamic blast loads Offers mitigation measures for structures in various environments Relates lab experiments to larger field tests Features more than 150 illustrations

  5. Auctioning incentive contracts: an experimental study

    NARCIS (Netherlands)

    Onderstal, S.; van de Meerendonk, A.

    2009-01-01

    In this note, we experimentally examine the relative performance of price-only auctions and multi-attribute auctions. We do so in procurement settings where the buyer can give the winning bidder incentives to exert effort on non-price dimensions after the auction. Both auctions theoretically

  6. Method to deterministically study photonic nanostructures in different experimental instruments

    NARCIS (Netherlands)

    Husken, B.H.; Woldering, L.A.; Blum, Christian; Tjerkstra, R.W.; Vos, Willem L.

    2009-01-01

    We describe an experimental method to recover a single, deterministically fabricated nanostructure in various experimental instruments without the use of artificially fabricated markers, with the aim to study photonic structures. Therefore, a detailed map of the spatial surroundings of the

  7. Experimental studies of Steel Corrugated Constructions

    Directory of Open Access Journals (Sweden)

    Lazarev Yuriy

    2016-01-01

    Full Text Available The purpose of this particular article is to assess existing calculations of steel corrugated constructions. Steel Corrugated Construction is a perspective type of constructions, which is exhibiting numerous advantages in comparison with one that currently applied in automobile and railroad networks (reinforced concrete water-throughput pipes, reinforced concrete frame bridges. The evaluation of experimental data on models of constructions of this particular type has been carried out in order to improve calculations of Steel Corrugated Constructions.

  8. Experimental studies of coaxial plasma gun current

    International Nuclear Information System (INIS)

    Price, D.W.

    1988-01-01

    In this investigation of a coaxial plasma gun, plasma sheath currents and related behavior are examined. Plasma behavior in the gun affects gun characteristics. Plasma gun applications are determined by the plasma behavior. The AFWL PUFF capacitor bank (72 μF, 29 nH, 120 kV) drives the plasma gun using a deuterium fill gas. The gas breakdown site is isolated from the dielectric/vacuum interface in the AFWL system. Two gas values deliver gas in the system. The first delivers gas from the gun breech and the second optional valve delivers gas to the gun muzzle. Currents and voltages are measured by Rogowski coils, B probes and capacitive voltage probes. A O-D slug model is used to predict the current, inductance, gun voltage and plasma sheath velocity. The slug model assumes the sheath transits the gun with all mass in the sheath. In the snowplow mode, the plasma sheath is thin with a sharp current rise and drop. Our system operated in a transition mode between the snowplow and deflagration modes with early snowplow behavior and late deflagration behavior. Neutrons are produced in a plasma pinch at the gun muzzle, indicating snowplow behavior. The slug theory models overall gun behavior to experimental accuracy. Experimental results are compared to four theories for plasma sheath velocities: the Alfven collisionally limited model, the Rosenbluth model, the Fishbine saturated model and a single particle drift model. Experimental velocities vary from 10 5 to 10 6 m/s. Only the single particle drift and the slug model calculations are of the right magnitude (8 x 10 5 m/s). The Fishbine and the Rosenbluth models predict slower velocities (2 x 10 5 m/s). The Alfven model is not applicable to this system

  9. Experimental Study of Cavitation in Laminar Flow

    OpenAIRE

    Croci , Kilian; Ravelet , Florent; ROBINET , Jean-Christophe; Danlos , Amélie

    2017-01-01

    An experimental setup has been especially developed in order to observe cavitation in laminar flows. Experiments have been carried out with a silicon oil of viscosity υ = 100cSt passing through a Venturi-type geometry with 18°/8° convergent/divergent angles respectively. The range of Reynolds numbers at the inlet section is between 350 and 1000. Two dynamic regimes are identified. They are characterized by two critical Reynolds numbers, induced by major hydrodynamic changes in the flow, in ad...

  10. Experimental studies of spallation on thin target

    International Nuclear Information System (INIS)

    Borne, F.; Crespin, S.; Drake, D.; Frehaut, J.; Ledoux, X.; Lochard, J.P.; Martinez, E.; Patin, Y.; Petibon, E.; Pras, Ph.; Boudard, A.; Legrain, R.; Leray, S.; Terrien, Y.; Bouyer, P.; Brochard, F.; Duchazeaubeneix, J.C.; Durand, J.M.; Meigo, S.I.; Milleret, G.; Thun, J.; Whittal, D.M.; Wlazlo, W.; Lebrun, C.; Lecolley, J.F.; Lecolley, F.R.; Lefebvres, F.; Louvel, M.; Varignon, C.; Menard, S.; Stugge, L.; Hanappe, F.

    2000-01-01

    Angular distribution of spallation neutrons induced by protons (0.8, 1.2 and 1.6 GeV) and deuterons (0.8 and 1.6 GeV beams on various thin targets have been measured at SATURNE (CEA Saclay/France) with two complementary experimental techniques: the time-of-flight measurement with tagged incident protons for low energy neutrons (2-400 MeV) and the use of a hydrogen converter associated are analysed, interpreted and finally compared with theoretical previsions of simulation codes using the TIERCE system including the intranuclear cascade codes of BERTINI and CUGNON. (authors)

  11. Experimental study of the nucleon spin structure

    Energy Technology Data Exchange (ETDEWEB)

    Litmaath, M.F.

    1996-05-07

    After introducing the theoretical framework, which includes DIS, the Quark Parton Model (QPM) and QCD, we describe the implementation of the experiment. The SMC uses a beam of 190 GeV naturally polarized muons, scattering off nucleons in a large cryogenic target containing protons or deuterons that are polarized through Dynamic Nuclear Polarization (DNP). The target material is located in two cells in a row, with opposite polarizations. Every 5 hours the polarizations of both cells are reversed. The target polarization is measured by an NMR system. The polarization of the beam is measured in a polarimeter, located downstream of the main experimental setup. (orig.).

  12. Experimental study of the nucleon spin structure

    International Nuclear Information System (INIS)

    Litmaath, M.F.

    1996-01-01

    After introducing the theoretical framework, which includes DIS, the Quark Parton Model (QPM) and QCD, we describe the implementation of the experiment. The SMC uses a beam of 190 GeV naturally polarized muons, scattering off nucleons in a large cryogenic target containing protons or deuterons that are polarized through Dynamic Nuclear Polarization (DNP). The target material is located in two cells in a row, with opposite polarizations. Every 5 hours the polarizations of both cells are reversed. The target polarization is measured by an NMR system. The polarization of the beam is measured in a polarimeter, located downstream of the main experimental setup. (orig.)

  13. Feasibility study of the AOSTA experimental campaign

    Directory of Open Access Journals (Sweden)

    Carta M.

    2016-01-01

    Full Text Available The reduction of the nuclear waste is one of the most important nuclear issues. The high radiotoxicity of the spent fuel is due to plutonium and some minor actinides (MAs such as neptunium, americium and curium, above all. One way to reduce their hazard is to destroy by fission MAs in appropriate nuclear reactors. To allow the MAs destruction an important effort have been done on the nuclear data due to the poor knowledge in this field. In the framework of one of the NEA Expert Group on Integral Experiments for Minor Actinide Management an analysis of the feasibility of MAs irradiation campaign in the TAPIRO fast research reactor is carried out. This paper provides preliminary results obtained by calculations modelling the irradiation, in different TAPIRO irradiation channels, of some CEA samples coming from the French experimental campaign OSMOSE, loaded with different contents of MAs, in order to access, through particular peak spectrometry, to their capture cross section. On the basis of neutron transport calculation results, obtained by both deterministic and Monte Carlo methods, an estimate of the irradiated samples counting levels from the AOSTA (Activation of OSMOSE Samples in TAPIRO experimental campaign is provided.

  14. Experimental thermochemical study of the monochloronitrobenzene isomers

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Lobo Ferreira, Ana I.M.C.; Moreno, Ana Rita G.

    2009-01-01

    The standard (p 0 = 0.1 MPa) molar enthalpies of formation of 2-, 3-, and 4-chloronitrobenzene isomers, in the crystalline state, at T = 298.15 K, were derived from the standard (p 0 = 0.1 MPa) massic energies of combustion, in oxygen, at T = 298.15 K, measured by rotating bomb combustion calorimetry. The standard molar enthalpies of sublimation of the isomers, at T = 298.15 K, were obtained by high temperature Calvet microcalorimetry. From the determined experimental data, the values of the gaseous standard (p 0 = 0.1 MPa) molar enthalpies of formation for the three monochloronitrobenzene isomers were derived. The gas-phase enthalpies of formation were also estimated by the empirical scheme developed by Cox showing that for meta- and para-chloronitrobenzene the estimated values are in close agreement with the experimental ones whereas, in the case of ortho-chloronitrobenzene it is shown that a different enthalpic interaction increment is needed, when the substituents in the adjacent carbon ring atoms are a chlorine atom and a nitro group

  15. Theoretical and experimental studies of elementary physics

    International Nuclear Information System (INIS)

    Bodek, A.; Ferbel, T.; Melissinos, A.C.; Olsen, S.; Slattery, P.; Tipton, P.; Das, A.; Hagen, C.R.; Rajeev, S.G.; Okubo, S.

    1992-01-01

    The experimental high energy physics program is directed toward the execution of experiments that probe the basic constituents of matter and the forces between them. These experiments are carried out at national and international accelerator facilities. At the current time, we are primarily concentrating on the following projects: Direct photon production in hadronic reactions (Fermilab E706); Production of hybrid mesons in the nuclear Coulomb field; The D-Zero experiment at the Tevatron collider; Deep inelastic neutrino- and electron-nucleon scattering at FNAL and SLAC; Nonlinear QED at critical field strengths at SLAC; The Experiments at KEK (AMY, 17keV neutrino); The CDF experiment at the Tevatron collider; and SSC-related detector R ampersand D on scintillating tile- and diamond-based calorimetry and microstrip tracking detectors

  16. Theoretical and experimental studies of elementary physics

    International Nuclear Information System (INIS)

    Bodek, A.; Ferbel, T.; Melissinos, A.C.; Olsen, S.; Slattery, P.; Tipton, P.; Das, A.; Hagen, C.R.; Rajeev, S.G.; Okubo, S.

    1992-05-01

    The experimental high energy physics program is directed toward the execution of experiments that probe the basic constituents of matter and the forces between them. These experiments are carried out at national and international accelerator facilities. At the current time, we are primarily concentrating on the following projects: Direct photon production in hadronic reactions; production of hybrid mesons in the nuclear Coulomb field; the D-Zero experiment at the Tevatron collider; deep inelastic neutrino- and electron-nucleon scattering at FNAL and SLAC; nonlinear QED at critical field strengths at SLAC; the experiments at KEK (AMY, 17keV neutrino); the CDF experiment at the Tevatron collider; and SSC-related detector R ampersand D on scintillating tile- and diamond-based calorimetry and microstrip tracking detectors

  17. Economic principles in communication: an experimental study.

    Science.gov (United States)

    De Jaegher, Kris; Rosenkranz, Stephanie; Weitzel, Utz

    2014-12-21

    This paper experimentally investigates how economic principles affect communication. In a simple sender-receiver game with common interests over payoffs, the sender can send a signal without a pre-given meaning in an infrequent or frequent state of the world. When the signal is costly, several theories (focal point theory, the intuitive criterion, evolutionary game theory) predict an efficient separating equilibrium, where the signal is sent in the infrequent state of the world (also referred to as Horn׳s rule). To analyze whether Horn׳s rule applies, and if so, which theory best explains it, we develop and test variants of the sender-receiver game where the theories generate discriminatory hypotheses. In costly signaling variants, our participants follow Horn׳s rule most of the time, in a manner that is best explained by focal point theory. In costless signaling variants, evolutionary game theory best explains our results. Here participants coordinate significantly more (less) often on a separating equilibrium where the signal is sent in the frequent state if they are primed to associate the absence of a signal with the infrequent (frequent) state of the world. We also find indications that a similar priming effect applies to costly signals. Thus, while the frequency with which participants follow Horn׳s rule in costly signaling variants is best explained by Horn׳s rule, the priming effect shows that some of our participants׳ behavior is best explained by evolutionary game theory even when signals are costly. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Experimental study of oxidative DNA damage

    DEFF Research Database (Denmark)

    Loft, Steffen; Deng, Xin-Sheng; Tuo, Jingsheng

    1998-01-01

    Animal experiments allow the study of oxidative DNA damage in target organs and the elucidation of dose-response relationships of carcinogenic and other harmful chemicals and conditions as well as the study of interactions of several factors. So far the effects of more than 50 different chemical ...

  19. Lithium hydride hydrolysis: experimental and kinetic study

    International Nuclear Information System (INIS)

    Charton, S.; Maupoix, C.; Brevet, A.; Delaunay, F.; Heintz, O.; Saviot, L.

    2006-01-01

    In this work has been studied the contribution of various analyses techniques in the framework, on the one hand of revealing the mechanisms implied in lithium hydride hydrolysis, and on the other hand of studying the kinetics of hydrogen production. Among the methods recently investigated, Raman spectroscopy, XPS and SIMS seem to be particularly attractive. (O.M.)

  20. Theoretical & Experimental Studies of Elementary Particles

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, Kevin [Univ. of Rochester, NY (United States)

    2012-10-04

    Abstract High energy physics has been one of the signature research programs at the University of Rochester for over 60 years. The group has made leading contributions to experimental discoveries at accelerators and in cosmic rays and has played major roles in developing the theoretical framework that gives us our ``standard model'' of fundamental interactions today. This award from the Department of Energy funded a major portion of that research for more than 20 years. During this time, highlights of the supported work included the discovery of the top quark at the Fermilab Tevatron, the completion of a broad program of physics measurements that verified the electroweak unified theory, the measurement of three generations of neutrino flavor oscillations, and the first observation of a ``Higgs like'' boson at the Large Hadron Collider. The work has resulted in more than 2000 publications over the period of the grant. The principal investigators supported on this grant have been recognized as leaders in the field of elementary particle physics by their peers through numerous awards and leadership positions. Most notable among them is the APS W.K.H. Panofsky Prize awarded to Arie Bodek in 2004, the J.J. Sakurai Prizes awarded to Susumu Okubo and C. Richard Hagen in 2005 and 2010, respectively, the Wigner medal awarded to Susumu Okubo in 2006, and five principal investigators (Das, Demina, McFarland, Orr, Tipton) who received Department of Energy Outstanding Junior Investigator awards during the period of this grant. The University of Rochester Department of Physics and Astronomy, which houses the research group, provides primary salary support for the faculty and has waived most tuition costs for graduate students during the period of this grant. The group also benefits significantly from technical support and infrastructure available at the University which supports the work. The research work of the group has provided educational opportunities

  1. A comparative analysis of on-line and classroom-based instructional formats for teaching social work research

    Directory of Open Access Journals (Sweden)

    David Westhuis

    2006-12-01

    Full Text Available Research comparing courses taught exclusively in traditional face-to-face settings versus courses taught entirely online have shown similar levels of student satisfaction. This article reports findings from a comparative study of student achievement in research skills from classes using two different instructional formats. One group used a classroom-based instructional format and the other group used an online web-based instructional format. Findings indicate that there were no statistically significant differences between the two class formats for eight out of eleven outcome student performance activities and ten out of 13 pedagogical strategies. There were large effect size differences based on class format on four of the student performance activities and for student satisfaction with six of the pedagogical methods. When statistically significant differences were found, it was determined that student performance on learning activities and satisfaction with pedagogical methods were higher for the students in the traditional class. The findings support the conclusions of several studies concerning the effectiveness of online teaching. Limitations and implications for further studies are also suggested.

  2. Experimental Study on Gastric Juice Secretion by ...

    African Journals Online (AJOL)

    管理平台

    2012-05-29

    May 29, 2012 ... Study on stomach physiological functions by ... mechanism of regulating gastric electrical activity and gastric juice secretion might become true by the .... samples was used in comparism among these different groups.

  3. Experimental studies of actinides in molten salts

    International Nuclear Information System (INIS)

    Reavis, J.G.

    1985-06-01

    This review stresses techniques used in studies of molten salts containing multigram amounts of actinides exhibiting intense alpha activity but little or no penetrating gamma radiation. The preponderance of studies have used halides because oxygen-containing actinide compounds (other than oxides) are generally unstable at high temperatures. Topics discussed here include special enclosures, materials problems, preparation and purification of actinide elements and compounds, and measurements of various properties of the molten volts. Property measurements discussed are phase relationships, vapor pressure, density, viscosity, absorption spectra, electromotive force, and conductance. 188 refs., 17 figs., 6 tabs

  4. Experimental studies of actinides in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Reavis, J.G.

    1985-06-01

    This review stresses techniques used in studies of molten salts containing multigram amounts of actinides exhibiting intense alpha activity but little or no penetrating gamma radiation. The preponderance of studies have used halides because oxygen-containing actinide compounds (other than oxides) are generally unstable at high temperatures. Topics discussed here include special enclosures, materials problems, preparation and purification of actinide elements and compounds, and measurements of various properties of the molten volts. Property measurements discussed are phase relationships, vapor pressure, density, viscosity, absorption spectra, electromotive force, and conductance. 188 refs., 17 figs., 6 tabs.

  5. Litigation and audit quality; two experimental studies

    NARCIS (Netherlands)

    Dijk, M. van

    1998-01-01

    This study examines the effect of litigation risk on auditors' willingness to yield to management pressure and to omit audit steps of the audit program in case of budget pressure. The results show that litigation risk has a significant impact on audit quality.

  6. Experimental Study of Flow Through Carotid Aneurysms

    Science.gov (United States)

    Masoomi, Faezeh; Mejia-Alvarez, Ricardo

    2017-11-01

    There is evidence that traditional endovascular techniques like coiling are not effective for treatment of wide-neck cerebral aneurysms. Flow Diverter Stents (FDS) have emerged as promising devices for treating complex aneurysms since they enable treatment of aneurysms that were considered untreatable before. Recent studies suggest a number of associated risks with FDS, including in-stent thrombosis, perianeurysmal edema, delayed hemorrhage, and perforator occlusions. Chong et al. simulated hemodynamic behavior using patient-specific data. From their study, it is possible to infer that the standard deviation of energy loss could be a good predictor for intervention success. The aim of this study is to investigate the flow in models of cerebral aneurysms before and after FDS insertion using PIV. These models will be based on actual clinical studies and will be fabricated with advanced additive manufacturing techniques. These data will then be used to explore flow parameters that could inform the likelihood of post-intervention aneurysm rupture, and help determine FDS designs that better suit any particular patient before its procedure.

  7. Time to Criterion: An Experimental Study.

    Science.gov (United States)

    Anderson, Lorin W.

    The purpose of the study was to investigate the magnitude of individual differences in time-to-criterion and the stability of these differences. Time-to-criterion was defined in two ways: the amount of elapsed time required to attain the criterion level and the amount of on-task time required to attain the criterion level. Ninety students were…

  8. Experimental study of highly viscous impinging jets

    Energy Technology Data Exchange (ETDEWEB)

    Gomon, M. [Univ. of Texas, Austin, TX (United States). Dept. of Mechanical Engineering

    1998-12-01

    The objective of this research is to study the behavior of highly viscous gravity-driven jets filling a container. Matters of interest are the formation of voids in the fluid pool during the filling process and the unstable behavior of the fluid in the landing region which manifests itself as an oscillating motion. The working fluids used in this research are intended to simulate the flow behavior of molten glass. Qualitative and quantitative results are obtained in a parametric study. The fraction of voids present in the fluid pool after the filling of the container is measured for different parameter values of viscosity and mass flow rate. Likewise, frequencies of the oscillating jet are measured. Results are inconclusive with regard to a correlation between parameter settings and void fractions. As for frequencies, power law correlations are established.

  9. Experimental study of highly viscous impinging jets

    International Nuclear Information System (INIS)

    Gomon, M.

    1998-12-01

    The objective of this research is to study the behavior of highly viscous gravity-driven jets filling a container. Matters of interest are the formation of voids in the fluid pool during the filling process and the unstable behavior of the fluid in the landing region which manifests itself as an oscillating motion. The working fluids used in this research are intended to simulate the flow behavior of molten glass. Qualitative and quantitative results are obtained in a parametric study. The fraction of voids present in the fluid pool after the filling of the container is measured for different parameter values of viscosity and mass flow rate. Likewise, frequencies of the oscillating jet are measured. Results are inconclusive with regard to a correlation between parameter settings and void fractions. As for frequencies, power law correlations are established

  10. Experimental Study of Flow in a Bifurcation

    Science.gov (United States)

    Fresconi, Frank; Prasad, Ajay

    2003-11-01

    An instability known as the Dean vortex occurs in curved pipes with a longitudinal pressure gradient. A similar effect is manifest in the flow in a converging or diverging bifurcation, such as those found in the human respiratory airways. The goal of this study is to characterize secondary flows in a bifurcation. Particle image velocimetry (PIV) and laser-induced fluorescence (LIF) experiments were performed in a clear, plastic model. Results show the strength and migration of secondary vortices. Primary velocity features are also presented along with dispersion patterns from dye visualization. Unsteadiness, associated with a hairpin vortex, was also found at higher Re. This work can be used to assess the dispersion of particles in the lung. Medical delivery systems and pollution effect studies would profit from such an understanding.

  11. Research on Hygiene Based on Fieldwork and Experimental Studies.

    Science.gov (United States)

    Yajima, Ichiro

    2017-01-01

    Several experimental studies on hygiene have recently been performed and fieldwork studies are also important and essential tools. However, the implementation of experimental studies is insufficient compared with that of fieldwork studies on hygiene. Here, we show our well-balanced implementation of both fieldwork and experimental studies of toxic-element-mediated diseases including skin cancer and hearing loss. Since the pollution of drinking well water by toxic elements induces various diseases including skin cancer, we performed both fieldwork and experimental studies to determine the levels of toxic elements and the mechanisms behind the development of toxic-element-related diseases and to develop a novel remediation system. Our fieldwork studies in several countries including Bangladesh, Vietnam and Malaysia demonstrated that drinking well water was polluted with high concentrations of several toxic elements including arsenic, barium, iron and manganese. Our experimental studies using the data from our fieldwork studies demonstrated that these toxic elements caused skin cancer and hearing loss. Further experimental studies resulted in the development of a novel remediation system that adsorbs toxic elements from polluted drinking water. A well-balanced implementation of both fieldwork and experimental studies is important for the prediction, prevention and therapy of toxic-element-mediated diseases.

  12. The Experimental Study to Support IVR Strategy

    International Nuclear Information System (INIS)

    Ma, L.; Lu, W.; Hu, T.

    2015-01-01

    For alleviating the severe accident damage in nuclear power plant, In-vessel retention (IVR) is used on the severe accident management strategy in light water reactor. The criterion of IVR effectiveness is the safety margin, the value that between the melt pool heat flux and the critical heat flux on the lower head, matching the design requirements. For enhance the safety margin, the melt pool heat flux and the critical heat flux should be investigated. In the molten pool, the heat transfer behavior of metal layer is the focus problem because of the thermal focus effect. Therefore, the HELM was built to study the heat transfer correlations under the IVR conditions. The Globe–Dropkin correlation and Chu-Churchill correlation has been widely used to calculate the heat flux in the metal layer. However, the Rayleigh number (Ra) for the developed Power Plant has been shown to exceed the valid range for the G–D correlation. At the same time, other studies have shown that most correlations are far from the G–D correlation. Therefore, HELM verified the G–D correlations under the high Ra condition. The relationship between axial and radial heat transfer in the metal layer will also been studied. The behaviors of CHF varying with angular positions and the concentrations of coolant chemistry are investigated by the FIRM facility. FIRM is built to embody some key factors that influence the CHF: the heater block is 30o arc of circle with full-scale radius, and is made of the copper block covered by a thin carbon steel layer. The test section can be positioned in three tilted angles. Also, the effect of coolant chemistry will be examined by the mixed solution of water, deionized water, boric acid and tri-sodium phosphate. (author)

  13. Experimental study of isovector spin sum rules

    International Nuclear Information System (INIS)

    Alexandre Deur; Peter Bosted; Volker Burkert; Donald Crabb; Kahanawita Dharmawardane; Gail Dodge; Tony Forest; Keith Griffioen; Sebastian Kuhn; Ralph Minehart; Yelena Prok

    2008-01-01

    We present the Bjorken integral extracted from Jefferson Lab experiment EG1b for 0.05 2 . The integral is fit to extract the twist-4 element f 2 p-n which is large and negative. Systematic studies of this higher twist analysis establish its legitimacy at Q 2 around 1 GeV 2 . We also extracted the isovector part of the generalized forward spin polarizability γ 0 . Although this quantity provides a robust test of Chiral Perturbation Theory, our data disagree with the calculations

  14. Experimental study of relative, turbulent diffusion

    DEFF Research Database (Denmark)

    Mann, J.; Ott, Søren; Andersen, J.S.

    1999-01-01

    The purpose is to study relative turbulent diffusion under controlled, reproducible conditions in the laboratory in order to estimate the constant C in Richardson-Obukhov's law. We get C #approx# 0.4 -- 0.6. We furthermore measure the distance-neighbourfunction, which is the probability density...... system with two computers each equipped with a frame grabber card. In the search for the best experimentalmethods we have revised the concept of local homogeneity and derived a law for the velocity--acceleration structure function. A second by-product of this effort is a relatively simple derivation...

  15. Experimental and modelling studies of infiltration

    International Nuclear Information System (INIS)

    Giudici, M.

    2004-01-01

    This presentation describes a study of infiltration in the unsaturated soil with the objective of estimating the recharge to a phreatic aquifer. The study area is at the border of the city of Milan (Northern Italy), which draws water for both domestic and industrial purposes from ground water resources located beneath the urban area. The rate of water pumping from the aquifer system has been varying during the XX century, depending upon the number of inhabitants and the development of industrial activities. This caused variations with time of the depth of the water table below the ground surface and in turn some emergencies: the two most prominent episodes correspond to the middle '70s, when the water table in the city centre was about 30 m below the undisturbed natural conditions, and to the last decade, when the water table has raised at a rate of approximately 1 m/year and caused infiltrations in deep constructions (garages and building foundations, the underground railways, etc.). We have developed four ground water flow models at different scales, which share some characteristics: they are based on quasi-3D approximation (horizontal flow in the aquifers and vertical flow in the aquitards), conservative finite-differences schemes for regular grid with square cells in the horizontal plane and are implemented with proprietary computer codes. Among the problems that were studied for the development of these models, I recall some numerical problems, related to the behaviour of the phreatic aquifer under conditions of strong exploitation. Model calibration and validation for ModMil has been performed with a two-stage process, i.e., using some of the available data for model calibration and the remaining data for model validation. The application of geophysical exploration techniques, in particular seismic and geo-electrical prospecting, has been very useful to complete the data and information on the hydro-geological structure obtained from stratigraphic logs

  16. Experimental study of isovector spin sum rules

    International Nuclear Information System (INIS)

    Deur, A.; Bosted, P.; Burkert, V.; Crabb, D.; Minehart, R.; Prok, Y.; Dharmawardane, V.; Dodge, G. E.; Kuhn, S. E.; Forest, T. A.; Griffioen, K. A.

    2008-01-01

    We present the Bjorken integral extracted from Jefferson Lab experiment EG1b for 0.05 2 2 . The integral is fit to extract the twist-4 element f 2 p-n which appears to be relatively large and negative. Systematic studies of this higher twist analysis establish its legitimacy at Q 2 around 1 GeV 2 . We also performed an isospin decomposition of the generalized forward spin polarizability γ 0 . Although its isovector part provides a reliable test of the calculation techniques of chiral perturbation theory, our data disagree with the calculations.

  17. Theoretical and experimental study of thermoacoustic engines

    Science.gov (United States)

    Raspet, Richard; Bass, Henry E.; Arnott, W. P.

    1992-12-01

    A three year study of thermoacoustic engines operating as prime movers and refrigerators was completed. The major thrust of this effort was the use and theoretical description of ceramic honeycomb structures as the active element in thermoacoustic engines. An air-filled demonstration prime mover was constructed and demonstrated at Acoustical Society of America and IEE meetings. A helium-filled test prime mover was designed and built an is being employed in studies of the threshold of oscillation as a function of temperature difference and pressure. In addition, acoustically based theories of the thermoacoustic engine have been developed and tested for a parallel plate stack at the Naval Postgraduate School and for a honeycomb stack at the University of Mississippi. Most of this work is described in detail in the attached publications. In this report we will give an overview of the research completed to date and its relationship to work performed at the Naval Postgraduate School and to future work at the University of Mississippi.

  18. Field experimentation in isotope-aided studies

    International Nuclear Information System (INIS)

    Zapata, F.

    1990-01-01

    Isotopic-aided studies involve the application of isotopically labelled fertilizer as tracers for the quantitative and precise determination of the fate of specific nutrient elements in the soil/plant system. The planning of isotopic-aided studies requires a different approach from that followed in the design of normal fertilizer trials because of the cost and supply of isotopically labelled materials, the use of highly specialized equipment and the need for skillful trained staff in the use of isotope techniques both in the field/greenhouse and the laboratory. This report is intended to highlight the main points to be considered while applying those techniques in the field or greenhouse. It has been well established that nuclear techniques are a powerful tool in agricultural research. One should take advantage of the use of such techniques if the following criteria are met: The isotope method is the only way to solve a particular question or to obtain a specific piece of information. There are other methods available for such a purpose but the nuclear method provides a direct and quick means to obtain the needed information resulting in higher economic return

  19. Experimental techniques for cement hydration studies

    Directory of Open Access Journals (Sweden)

    Andreas Luttge

    2011-10-01

    Full Text Available Cement hydration kinetics is a complex problem of dissolution, nucleation and growth that is still not well understood, particularly in a quantitative way. While cement systems are unique in certain aspects they are also comparable to natural mineral systems. Therefore, geochemistry and particularly the study of mineral dissolution and growth may be able to provide insight and methods that can be utilized in cement hydration research. Here, we review mainly what is not known or what is currently used and applied in a problematic way. Examples are the typical Avrami approach, the application of Transition State Theory (TST to overall reaction kinetics and the problem of reactive surface area. Finally, we suggest an integrated approach that combines vertical scanning interferometry (VSI with other sophisticated analytical techniques such as atomic force microscopy (AFM and theoretical model calculations based on a stochastic treatment.

  20. Experimental study of diffuse auroral precipitations

    International Nuclear Information System (INIS)

    Mouaia, K.

    1983-01-01

    First chapter is devoted to low energy electron precipitation in the evening sector of the auroral magnetosphere, during quiet and disturbed magnetic periods. Four subjects are studied in detail: the latitude distribution of the varied auroral forms and their relations to external magnetosphere; the time coefficients related to precipitations, the form and the dynamic of the diffuse precipitation equatorial frontier; the precipitation effect on the ionosphere concentration. The last part of the chapter shows that the plasma convection in the magnetosphere, associated to wave-particle interactions near the equatorial accounts for the principal characteristics of the evening sector diffuse electronic precipitations. The second chapter deals with subauroral precipitations of low energy ions, after the magnetospheric substorms, in the high latitude regions of the morning sector [fr

  1. Experimental study on the adiabatic shear bands

    International Nuclear Information System (INIS)

    Affouard, J.

    1984-07-01

    Four martensitic steels (Z50CDV5 steel, 28CND8 steel, 35NCDV16 steel and 4340 steel) with different hardness between 190 and 600 Hsub(B) (Brinell hardness), have been studied by means of dynamic compressive tests on split Hopkinson pressure bar. Microscopic observations show that the fracture are associated to the development of adiabatic shear bands (except 4340 steel with 190 Hsub(B) hardness). By means of tests for which the deformation is stopped at predetermined levels, the measurement of shear and hardness inside the band and the matrix indicates the chronology of this phenomenon: first the localization of shear, followed by the formation of adiabatic shear band and ultimatly crack initiation and propagation. These results correlated with few simulations by finite elements have permitted to suggest two mecanisms of deformation leading to the formation of adiabatic shear bands in this specific test [fr

  2. Mortar alteration: experimental study and ancient analogues

    International Nuclear Information System (INIS)

    Rassineux, Francois

    1987-01-01

    As the durability of cemented matrices is a matter of great importance in numerous domains, notably for the long term reliability of surface storages of radioactive wastes, the objective of this research thesis is to define mechanisms of evolution of cemented matrices when in contact with diluted aqueous solutions. The author notably studied the influence of the lixiviation mode on the evolution of two mortars having different compositions (pH, CO 2 pressure, system containment, and cement mineralogical nature appear to be the main governing parameters), the alteration (dissolution is the prevailing process in the interaction between cemented matrices and a diluted solution such as rain water), and ancient binders (archaeological binders containing mineral phases such as hydrated calcium silicates or hydro-grossulars). The obtained results lead to the definition of alteration mechanisms in modern cements, and highlight factors governing the durability of these materials when submitted to meteoric alteration [fr

  3. Experimental Study of Liquid Fuel Spray Combustion

    DEFF Research Database (Denmark)

    Westlye, Fredrik Ree

    the specific physical quantities needed in CFD validation of these types of flames. This work is a testament to that fact. The first part of this thesis is an extensive study of optical combustion diagnostics applied to complex transient sprayflames in a high temperature and pressure environment...... by the Danish Council for Strategic Research. Other supporters of the project have been MAN Diesel & Turbo A/S, DTU Mechanical Engineering, DTU Chemical Engineering, Sandia National Laboratories USA, Norwegian University of Science & Technology (NTNU) and University of Nottingham, Malaysia Campus.......The physiochemical properties and electromagnetic interactions in flames, of which various optical combustion diagnostics are based, have been reviewed. Key diagnostics have been presented with practical examples of their application which, together with a comprehensive review of fuel spray flames, form...

  4. Preliminary experimental studies of waste coal gasification

    Energy Technology Data Exchange (ETDEWEB)

    Su, S.; Jin, Y.G.; Yu, X.X.; Worrall, R. [CSIRO, Brisbane, QLD (Australia). Advanced Coal Technology

    2013-07-01

    Coal mining is one of Australia's most important industries. It was estimated that coal washery rejects from black coal mining was approximately 1.82 billion tonnes from 1960 to 2009 in Australia, and is projected to produce another one billion tonnes by 2018 at the current production rate. To ensure sustainability of the Australian coal industry, we have explored a new potential pathway to create value from the coal waste through production of liquid fuels or power generation using produced syngas from waste coal gasification. Consequently, environmental and community impacts of the solid waste could be minimized. However, the development of an effective waste coal gasification process is a key to the new pathway. An Australian mine site with a large reserve of waste coal was selected for the study, where raw waste coal samples including coarse rejects and tailings were collected. After investigating the initial raw waste coal samples, float/sink testing was conducted to achieve a desired ash target for laboratory-scale steam gasification testing and performance evaluation. The preliminary gasification test results show that carbon conversions of waste coal gradually increase as the reaction proceeds, which indicates that waste coal can be gasified by a steam gasification process. However, the carbon conversion rates are relatively low, only reaching to 20-30%. Furthermore, the reactivity of waste coal samples with a variety of ash contents under N{sub 2}/air atmosphere have been studied by a home-made thermogravimetric analysis (TGA) apparatus that can make the sample reach the reaction temperature instantly.

  5. Experimental and clinical studies with intraoperative radiotherapy

    International Nuclear Information System (INIS)

    Sindelar, W.F.; Kinsella, T.; Tepper, J.; Travis, E.L.; Rosenberg, S.A.; Glatstein, E.

    1983-01-01

    Studies of normal tissue tolerance to intraoperative radiotherapy were done upon 65 dogs subjected to laparotomy and 11 million electron volt electron irradiation in doses ranging from zero to 5,000 rads. Results of studies indicated that intact aorta and vena cava tolerate up to 5,000 rads without loss of structural integrity. Ureteral fibrosis and stenosis develop at doses of 3,000 rads or more. Arterial anastomoses heal after doses of 4,500 rads, but fibrosis can lead to occlusion. Intestinal suture lines heal after doses of 4,500 rads. Bile duct fibrosis and stenosis develop at doses of 2,000 rads or more. Biliary-enteric anastomoses fail to heal at any dose level. A clinical trial of intraoperative radiotherapy combined with radical surgery was performed upon 20 patients with advanced malignant tumors which were considered unlikely to be cured by conventional therapies and which included carcinomas of the stomach, carcinomas of the pancreas, carcinomas involving the hilus of the liver, retroperitoneal sarcomas and osteosarcomas of the pelvis. All patients underwent resection of gross tumor, followed by intraoperative irradiation of the tumor bed and regional nodal basins. Some patients received additional postoperative external beam radiotherapy. Treatment mortality for combined operation and radiotherapy occurred in four of 20 patients. Postoperative complications occurred in four of the 16 surviving patients. Local tumor control was achieved in 11 of the 16 surviving patients, with an over-all median follow-up period of 18 months. The clinical trial suggested that intraoperative radiotherapy is a feasible adjunct to resection in locally advanced tumors, that the resulting mortality and morbidity is similar to that expected from operation alone and that local tumor control may be improved

  6. Experimental studies of rotating exchange flow

    Science.gov (United States)

    Rabe, B.; Smeed, D. A.; Dalziel, S. B.; Lane-Serff, G. F.

    2007-02-01

    Ocean basins are connected by straits and passages, geometrically limiting important heat and salt exchanges which in turn influence the global thermohaline circulation and climate. Such exchange can be modeled in an idealized way by taking into consideration the density-driven two-layer flow along a strait under the influence of rotation. We use a laboratory model of a lock exchange between two reservoirs of different density through a flat-bottom channel with a horizontal narrows, set up on two different platforms: a 1 m diameter turntable, where density interface position was measured by dye attenuation, and the 14 m diameter turntable at Coriolis/LEGI (Grenoble, France), where correlation imaging velocimetry, a particle imaging technique, allowed us to obtain for the first time detailed measurements of the velocity fields in these flows. The influence of rotation is studied by varying a parameter, Bu, a type of Burger number given by the ratio of the Rossby radius to the channel width at the narrows. In addition, a two-layer version of the Miami Isopycnic Coordinate Model (MICOM) is used, to study the cases with low Burger number. Results from experiments by Dalziel [1988. Two-layer hydraulics: maximal exchange flows. Ph.D. Thesis, Department of Applied Mathematics and Theoretical Physics, University of Cambridge, see also people/sd103/papers/1988/Thesis_Dalziel.pdf>] are also included for comparison. Time-mean exchange fluxes for any Bu are in close agreement with the inviscid zero-potential vorticity theory of Dalziel [1990. Rotating two-layer sill flows. In: Pratt, L.J. (Ed.), The Physical Oceanography of Sea Straits. Kluwer Academic, Dordrecht, pp. 343-371] and Whitehead et al. [1974. Rotating hydraulics of strait and sill flows. Geophysical Fluid Dynamics 6, 101-125], who found that fluxes for Bu>1 mainly vary with channel width, similar to non-rotating flow, but for Bu1 a steady, two-layer flow was observed that persisted across the channel at the narrows

  7. Classroom-based Interventions and Teachers' Perceived Job Stressors and Confidence: Evidence from a Randomized Trial in Head Start Settings.

    Science.gov (United States)

    Zhai, Fuhua; Raver, C Cybele; Li-Grining, Christine

    2011-09-01

    Preschool teachers' job stressors have received increasing attention but have been understudied in the literature. We investigated the impacts of a classroom-based intervention, the Chicago School Readiness Project (CSRP), on teachers' perceived job stressors and confidence, as indexed by their perceptions of job control, job resources, job demands, and confidence in behavior management. Using a clustered randomized controlled trial (RCT) design, the CSRP provided multifaceted services to the treatment group, including teacher training and mental health consultation, which were accompanied by stress-reduction services and workshops. Overall, 90 teachers in 35 classrooms at 18 Head Start sites participated in the study. After adjusting for teacher and classroom factors and site fixed effects, we found that the CSRP had significant effects on the improvement of teachers' perceived job control and work-related resources. We also found that the CSRP decreased teachers' confidence in behavior management and had no statistically significant effects on job demands. Overall, we did not find significant moderation effects of teacher race/ethnicity, education, teaching experience, or teacher type. The implications for research and policy are discussed.

  8. Experimental and clinical studies on CT lymphography

    International Nuclear Information System (INIS)

    Hirata, Yuzo; Kono, Michio

    1982-01-01

    Indirect lymphography using computed tomographic apparatus (CT Lymphography) was attempted in 15 dogs with newly devised contrast medium for the opacification of hilar and mediastinal lymphnodes. Clinical application was performed in 2 cases of lung cancer. Newly devised contrast material is an emulsion, which consists of oily contrast medium, non-ionic surfactant and glucose solution. The contrast medium was injected percutaneously into subdiaphragmatic space, or into bronchial walls by bronchofiberscopic technique. CT was able to demonstrate the opacified hilar and mediastinal nodes much more in number than demonstrated in conventional radiograms. It was true in 6 to 11 cases when injected into subdiaphragmatic spaces, and in 2 of 4 cases with an injection into bronchial walls. In clinical studies, CT revealed opacification of mediastinal nodes in one case of lung cancer. Although the procedure is still inferior to the demonstrability of routine indirect lymphography for the evaluation of the fine structure of each node, it showed no remarkable side effects. As the satisfactory method of opacifying hilar and mediastinal nodes has not yet been established, our method is thought to be of value in applying for detection of the metastatic lymphnodes. (author)

  9. Experimental study of acoustic vibration in BWRs

    International Nuclear Information System (INIS)

    Kumagai, Kosuke; Someya, Satoshi; Okamoto, Koji

    2009-01-01

    In recent years, the power uprate of Boiling Water Reactors have been conducted at several existing power plants as a way to improve plant economy. In one of the power uprated plants (117.8% uprates) in the United States, the steam dryer breakages due to fatigue fracture occurred. It is conceivable that the increased steam flow passing through the branches caused a self-induced vibration with the propagation of sound wave into the steam-dome. The resonance among the structure, flow and the pressure fluctuation resulted in the breakages. To understand the basic mechanism of the resonance, previous researches were done by a point measurement of the pressure and by a phase averaged measurement of the flow, while it was difficult to detect the interaction among them by the conventional method. In this study, Dynamic Particle Image Velocimetry (PIV) System was applied to investigate the effect of sound on natural convection and forced convection. Dynamic PIV system is the newest entrant to the field of fluid flow measurement. Its paramount advantage is the instantaneous global evaluation of conditions over plane extended across the whole velocity field. Also, to evaluate the coupling between the acoustic wave and structure (simulated as tuning fork vibrator in this experiment), in the resonance frequency of tuning fork vibrator, fluid behavior and the motion of tuning fork vibrator are measured simultaneously. (author)

  10. Experimental thermochemical study of two chlorodinitroaniline isomers

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Ribeiro da Silva, Maria D.M.C.; Santos, Ana Filipa L.O.M.; Ferreira, Ana I.M.C. Lobo; Galvao, Tiago L.P.

    2010-01-01

    The standard (p 0 =0.1MPa) molar enthalpies of formation of 2-chloro-4,6-dinitroaniline and 4-chloro-2,6-dinitroaniline, in the gaseous phase, at T = 298.15 K, were derived from the combination of the values of the standard molar enthalpies of formation, in the crystalline phase, and of the standard molar enthalpies of sublimation, at the same temperature. The standard molar enthalpies of formation, in the crystalline phase, were derived from the standard massic energies of combustion, in oxygen, measured by rotating-bomb combustion calorimetry. The standard molar enthalpies of sublimation were calculated, by the application of the Clausius-Clapeyron equation, to the vapour pressures at several temperatures, measured by Knudsen effusion technique. The values of the standard molar enthalpies of formation of 2-chloro-4,6-dinitroaniline and 4-chloro-2,6-dinitroaniline, in the gaseous phase, at T = 298.15 K, are discussed in terms of enthalpic increments, and the enthalpy of isomerization between the two compounds is compared with the same parameter for two isomers of chloronitroaniline, studied in previous works.

  11. Experimental Studies of Electrothermal Plasma Gun

    International Nuclear Information System (INIS)

    Diab, F.B.A.

    2013-01-01

    The aim of the present work is to study the capillary plasma discharge dynamics and characteristics. The capillary plasma device is a new technology for producing high density plasma after ablating the capillary wall using a pulsed electric power. An Electrothermal Plasma Gun (ETG) is composed of a capillary discharge tube made of Teflon operated with simple RLC circuit. The device called Electrothermal Gun (ETG) which is composed of 4 capacitors (70 μF, 10 kV, 1.28 μH) connected in parallel to a plasma source by means of one high power supply. The gun was operated in open air at discharge energies between 35 J - 3.5 kJ according to charging voltage. The work presented in this thesis covers the following items, 1- Measurements of the basic parameters and characterizations of the pretest results of the electrical circuits and capillary plasma discharge using Rogowski coil, voltage probe and Photomultiplier. 2- Material processing including (physics of the surface modifications, the morphology of the surface by using Scanning Electron Microscope (SEM) at different conditions, compositions of the materials by using X-ray Fluorescence (XRF), Micro hardness test and material particle deposition.

  12. Experimental study of canvas characterization for paintings

    Science.gov (United States)

    Cornelis, Bruno; Dooms, Ann; Munteanu, Adrian; Cornelis, Jan; Schelkens, Peter

    2010-02-01

    The work described here fits in the context of a larger project on the objective and relevant characterization of paintings and painting canvas through the analysis of multimodal digital images. We captured, amongst others, X-ray images of different canvas types, characterized by a variety of textures and weave patterns (fine and rougher texture; single thread and multiple threads per weave), including raw canvas as well as canvas processed with different primers. In this paper, we study how to characterize the canvas by extracting global features such as average thread width, average distance between successive threads (i.e. thread density) and the spatial distribution of primers. These features are then used to construct a generic model of the canvas structure. Secondly, we investigate whether we can identify different pieces of canvas coming from the same bolt. This is an important element for dating, authentication and identification of restorations. Both the global characteristics mentioned earlier and some local properties (such as deviations from the average pattern model) are used to compare the "fingerprint" of different pieces of cloth coming from the same or different bolts.

  13. Experimental study of high beta toroidal plasmas

    International Nuclear Information System (INIS)

    Kellman, A.G.

    1983-09-01

    Experiments on the Wisconsin Levitated Toroidal Octupole have produced a wide range of stable high β plasmas with β significantly above single fluid MHD theory predictions. A stable β approx. 8% plasma, twice the fluid limit, is obtained with 5 rho/sub i/ approx. L/sub n/ and tau/sub β/ approx. = 6000 tau/sub Alfven/ = 600 μsec. The enhanced stability is explained with a kinetic treatment that includes the effect of finite ion gyroradius which couples the ballooning mode to an ion drift wave. In a more collisional, large gyroradius (2 rho/sub i/ approx. L/sub n/) regime, a stable β approx. 35% plasma is obtained with a decay time of 1000 Alfven times. Measurement of the equilibrium magnetic field in this regime indicates that the diamagnetic current density is five times smaller than predicted by ideal MHD, probably due to ion gyroviscosity. Particle transport is anomalous and ranges from agreement with the classical diffusion rate at the highest beta, lowest field plasma (B/sub P/ = 200 G), to thirteen times the classical rate in a β=11%, high field plasma (B/sub P/ = 860 G) where the level of enhancement increase with magnetic field. Fluctuations in density, electrostatic potential, and magnetic field have been studied in plasmas with β from 0.1% to 40%

  14. Experimental study of flow through compressor Cascade

    Directory of Open Access Journals (Sweden)

    Satyam Panchal

    2017-09-01

    Full Text Available The objective of this research work is to study the behaviour of flow at the inlet, within the blade passage and at the exit of a compressor cascade. For this purpose, a cascade with six numbers of aerofoil blades was designed and constructed. The cascade was fitted on the cascade test tunnel. Out of six blades two were instrumented for measuring the pressure distribution on the pressure and suction surface. The blades had a parabolic camber line, with a maximum camber position at 40% of the chord from the leading edge of the blade. The profile of the blade was C4, height of the blade was 160 mm, chord length was 80 mm, camber angle was 45° and stagger angle was 30°. Similarly, the length of the cascade was 300 mm, span was 160 mm, pitch was 60 mm, the actual chord of the cascade was 80 mm, the axial chord of the cascade was 70 mm, the stagger angle of the cascade was 30° and the pitch-chord ratio was 0.75. The data was taken and analyzed at −500% of the axial chord before the cascade, −25% of the axial chord before the leading edge, 25%, 50%, 75% and 150% of the axial chord from the leading edge of the blade. The readings were taken from the cascade wall to the mid span position along the pitch wise direction. The angle of incidence was also changed during the experiment and varied from i=−50°, −30°, −10° to 5°.

  15. Markets and Morals: An Experimental Survey Study

    Science.gov (United States)

    Elias, Julio J.; Lacetera, Nicola; Macis, Mario

    2015-01-01

    Most societies prohibit some market transactions based on moral concerns, even when the exchanges would benefit the parties involved and would not create negative externalities. A prominent example is given by payments for human organs for transplantation, banned virtually everywhere despite long waiting lists and many deaths of patients who cannot find a donor. Recent research, however, has shown that individuals significantly increase their stated support for a regulated market for human organs when provided with information about the organ shortage and the potential beneficial effects a price mechanism. In this study we focused on payments for human organs and on another “repugnant” transaction, indoor prostitution, to address two questions: (A) Does providing general information on the welfare properties of prices and markets modify attitudes toward repugnant trades? (B) Does additional knowledge on the benefits of a price mechanism in a specific context affect attitudes toward price-based transactions in another context? By answering these questions, we can assess whether eliciting a market-oriented approach may lead to a relaxation of moral opposition to markets, and whether there is a cross-effect of information, in particular for morally controversial activities that, although different, share a reference to the “commercialization” of the human body. Relying on an online survey experiment with 5,324 U.S. residents, we found no effect of general information about market efficiency, consistent with morally controversial markets being accepted only when they are seen as a solution to a specific problem. We also found some cross-effects of information about a transaction on the acceptance of the other; however, the responses were mediated by the gender and (to a lesser extent) religiosity of the respondent—in particular, women exposed to information about legalizing prostitution reduced their stated support for regulated organ payments. We relate

  16. Markets and morals: an experimental survey study.

    Directory of Open Access Journals (Sweden)

    Julio J Elias

    Full Text Available Most societies prohibit some market transactions based on moral concerns, even when the exchanges would benefit the parties involved and would not create negative externalities. A prominent example is given by payments for human organs for transplantation, banned virtually everywhere despite long waiting lists and many deaths of patients who cannot find a donor. Recent research, however, has shown that individuals significantly increase their stated support for a regulated market for human organs when provided with information about the organ shortage and the potential beneficial effects a price mechanism. In this study we focused on payments for human organs and on another "repugnant" transaction, indoor prostitution, to address two questions: (A Does providing general information on the welfare properties of prices and markets modify attitudes toward repugnant trades? (B Does additional knowledge on the benefits of a price mechanism in a specific context affect attitudes toward price-based transactions in another context? By answering these questions, we can assess whether eliciting a market-oriented approach may lead to a relaxation of moral opposition to markets, and whether there is a cross-effect of information, in particular for morally controversial activities that, although different, share a reference to the "commercialization" of the human body. Relying on an online survey experiment with 5,324 U.S. residents, we found no effect of general information about market efficiency, consistent with morally controversial markets being accepted only when they are seen as a solution to a specific problem. We also found some cross-effects of information about a transaction on the acceptance of the other; however, the responses were mediated by the gender and (to a lesser extent religiosity of the respondent--in particular, women exposed to information about legalizing prostitution reduced their stated support for regulated organ payments. We

  17. Markets and morals: an experimental survey study.

    Science.gov (United States)

    Elias, Julio J; Lacetera, Nicola; Macis, Mario

    2015-01-01

    Most societies prohibit some market transactions based on moral concerns, even when the exchanges would benefit the parties involved and would not create negative externalities. A prominent example is given by payments for human organs for transplantation, banned virtually everywhere despite long waiting lists and many deaths of patients who cannot find a donor. Recent research, however, has shown that individuals significantly increase their stated support for a regulated market for human organs when provided with information about the organ shortage and the potential beneficial effects a price mechanism. In this study we focused on payments for human organs and on another "repugnant" transaction, indoor prostitution, to address two questions: (A) Does providing general information on the welfare properties of prices and markets modify attitudes toward repugnant trades? (B) Does additional knowledge on the benefits of a price mechanism in a specific context affect attitudes toward price-based transactions in another context? By answering these questions, we can assess whether eliciting a market-oriented approach may lead to a relaxation of moral opposition to markets, and whether there is a cross-effect of information, in particular for morally controversial activities that, although different, share a reference to the "commercialization" of the human body. Relying on an online survey experiment with 5,324 U.S. residents, we found no effect of general information about market efficiency, consistent with morally controversial markets being accepted only when they are seen as a solution to a specific problem. We also found some cross-effects of information about a transaction on the acceptance of the other; however, the responses were mediated by the gender and (to a lesser extent) religiosity of the respondent--in particular, women exposed to information about legalizing prostitution reduced their stated support for regulated organ payments. We relate these

  18. An experimental study on pump clogging

    International Nuclear Information System (INIS)

    Isono, M; Nohmi, M; Uchida, H; Kawai, M; Kudo, H; Kawahara, T; Miyagawa, K; Saito, S

    2014-01-01

    For sewage pump that various foreign substance is flowed into, anti-clogging performance is a factor as important as pump efficiency in order to avoid clogging trouble by foreign substance. Many investigations about pump inner flow and pump efficiency estimation have been carried out conventionally in order to realize coexistence with anti-clogging performance and pump performance. And these results have been reflected in construction of the running water section design method. As a index of anti-clogging performance, ''impeller passage diameter'' which is diameter of spherical solid that can pass through the pump is used widely. And there are various type of the sewage pump which have large impeller passage diameter. However real cause of clog is not a solid, and it is fibrous material such as towel and clothes, vinyl and paper diaper. In most case these material accumulate in the pump, so that clog is occurred. In this study, for the purpose of quantification of anti-clogging performance against fibrous materials, the factor that affect to clogging of pump was investigated by pump model test using a string. The test is done based on Taguchi method. In this test, type of the pump model, diameter of the string, material of the string, length of the string and flow rate are selected for the factor, and the effect that they have on the clogging of the pump was investigated. As a result of this test, it was made clear that length of the string has a strong influence on the clogging of the pump. And from the result of this test, evaluation method of anti-clogging performance of the pump against fibrous material by using string was considered. According to the result of above test based on Taguchi method, it was assumed that quantification of anti-clogging performance against fibrous materials is possible by flowing plural strings into the pump and calculating the probability of passing. Plurality sewage pumps of different types were evaluated based

  19. Peer-Review Writing Workshops in College Courses: Students’ Perspectives about Online and Classroom Based Workshops

    Directory of Open Access Journals (Sweden)

    Erin B. Jensen

    2016-11-01

    Full Text Available Peer-review workshops are commonly used in writing courses as a way for students to give their peers feedback as well as help their own writing. Most of the research on peer-review workshops focuses on workshops held in traditional in-person courses, with less research on peer-review workshops held online. Students in a freshman writing course experienced both a classroom based writing workshop and an online workshop and then took a survey about their experiences. The majority of the students preferred the online writing workshop because of the convenience of the workshop and being able to post anonymous reviews. Students whom preferred the traditional in-person writing workshop liked being able to talk with their peers about their papers. This research article focuses on the students’ responses and experiences with traditional and online peer-reviews.

  20. Theoretical and Experimental Studies in Accelerator Physics

    Energy Technology Data Exchange (ETDEWEB)

    Rosenzweig, James [Univ. of California, Los Angeles, CA (United States). Dept. of Physics and Astronomy

    2017-03-08

    . We note also that PBPL graduates remain as close elaborators for the program after leaving UCLA. The UCLA PBPL program is a foremost developer of on-campus facilities, such as the Neptune and Pegasus Laboratories, providing a uniquely strong environment for student-based research. In addition, the PBPL is a strong user of off-campus national lab facilities, such as SLAC FACET and NLCTA, and the BNL ATF. UCLA has also vigorously participated in the development of these facilities. The dual emphases on off- and on-campus opportunities permit the PBPL to address in an agile way a wide selection of cutting-edge research topics. The topics embraced by this proposal illustrate this program aspect well. These include: GV/m dielectric wakefield acceleration/coherent Cerenkov radiation experiments at FACET (E-201) and the ATF; synergistic laser-excited dielectric accelerator and light source development; plasma wakefield (PWFA) experiments on “Trojan horse” ionization injection (FACET E-210), quasi-nonlinear PWFA at BNL and the production at Neptune high transformer ratio plasma wakes; the inauguration of a new type of RF photoinjector termed “hybrid” at UCLA, and application to PWFA; space-charge dominated beam and cathode/near cathode physics; the study of advanced IFEL systems, for very high energy gain and utilization of novel OAM modes; the physcis of inverse Compton scattering (ICS), with applications to e+ production and γγ colliders; electron diffraction; and advanced beam diagnostics using coherent imaging techniques. These subjects are addressed under the leadership of PBPL director Prof. James Rosenzweig in Task A, and Prof. Pietro Musumeci in Task J, which was initiated following his OHEP Outstanding Junior Investigator award.

  1. Injury Based on Its Study in Experimental Models

    Directory of Open Access Journals (Sweden)

    M. Mendes-Braz

    2012-01-01

    Full Text Available The present review focuses on the numerous experimental models used to study the complexity of hepatic ischemia/reperfusion (I/R injury. Although experimental models of hepatic I/R injury represent a compromise between the clinical reality and experimental simplification, the clinical transfer of experimental results is problematic because of anatomical and physiological differences and the inevitable simplification of experimental work. In this review, the strengths and limitations of the various models of hepatic I/R are discussed. Several strategies to protect the liver from I/R injury have been developed in animal models and, some of these, might find their way into clinical practice. We also attempt to highlight the fact that the mechanisms responsible for hepatic I/R injury depend on the experimental model used, and therefore the therapeutic strategies also differ according to the model used. Thus, the choice of model must therefore be adapted to the clinical question being answered.

  2. Experimental studies on an indigenous coconut shell based ...

    Indian Academy of Sciences (India)

    Experimental studies are carried out to characterize an indigenous, coconut shell based, activated carbon suitable for storage of natural gas. Properties such as BET surface area, micropore volume, average pore diameter and pore size distribution are obtained by using suitable instruments and techniques. An experimental ...

  3. Experimental studies on caisson-type porous seawalls

    Science.gov (United States)

    Zhu, Shutang; Chwang, A. T.

    2002-08-01

    This paper presents experimental studies on the reflection characteristics of caisson-type porous seawalls under designed wave conditions. The results of physical model experiments are plotted and discussed. Comparisons between experimental results and analytical predictions are also made and the agreement is found to be very good.

  4. The experimental study of seed dispersal by fish (ichthyochory)

    NARCIS (Netherlands)

    Pollux, B.J.A.

    2011-01-01

    1.The last few years have seen an increased interest in the experimental study of seed dispersal by fish (ichthyochory). This paper reviews such experiments, aiming to determine what functional aspects of ichthyochory have been investigated, what experimental designs have been used and what the

  5. Study of TXRF experimental system by Monte Carlo simulation

    International Nuclear Information System (INIS)

    Costa, Ana Cristina M.; Leitao, Roberta G.; Lopes, Ricardo T.; Anjos, Marcelino J.; Conti, Claudio C.

    2011-01-01

    The Total-Reflection X-ray Fluorescence (TXRF) technique offers unique possibilities to study the concentrations of a wide range of trace elements in various types of samples. Besides that, the TXRF technique is widely used to study the trace elements in biological, medical and environmental samples due to its multielemental character as well as simplicity of sample preparation and quantification methods used. In general the TXRF experimental setup is not simple and might require substantial experimental efforts. On the other hand, in recent years, experimental TXRF portable systems have been developed. It has motivated us to develop our own TXRF portable system. In this work we presented a first step in order to optimize a TXRF experimental setup using Monte Carlo simulation by MCNP code. The results found show that the Monte Carlo simulation method can be used to investigate the development of a TXRF experimental system before its assembly. (author)

  6. Refining the Construct of Classroom-Based Writing-from-Readings Assessment: The Role of Task Representation

    Science.gov (United States)

    Wolfersberger, Mark

    2013-01-01

    This article argues that task representation should be considered as part of the construct of classroom-based academic writing. Task representation is a process that writers move through when creating a unique mental model of the requirements for each new writing task they encounter. Writers' task representations evolve throughout the composing…

  7. Experimental and theoretical studies of bombardment induced surface morphology changes

    International Nuclear Information System (INIS)

    Carter, G.; Nobes, M.J.; Williams, J.S.

    1980-01-01

    In this review results of experimental and theoretical studies of solid surface morphology changes due to ion bombardment are discussed. An attempt is undertaken to classify the observed specific features of a structure, generated by ion bombardment [ru

  8. Studies on pathogenesis and treatment of experimental immune complex glomerulonephrtis.

    NARCIS (Netherlands)

    Fleuren, Gerard Johannes Maria

    1976-01-01

    Chapter 1. In this thesis an investigation into pathogenetic mechanisms of epimembranous immune complex depostion in the glomeruli was described. For this study we used two related models of experimental immune complex glemerulonephritis: the heterologous and the autologous immune complex

  9. Experimental studies of occupation times in turbulent flows

    DEFF Research Database (Denmark)

    Mann, J.; Ott, Søren; Pécseli, H.L.

    2003-01-01

    The motion of passively convected particles in turbulent flows is studied experimentally in approximately homogeneous and isotropic turbulent flows, generated in water by two moving grids. The simultaneous trajectories of many small passively convected, neutrally buoyant, polystyrene particles...

  10. Biofouling in forward osmosis systems: An experimental and numerical study

    KAUST Repository

    Bucs, Szilard; Valladares Linares, Rodrigo; Vrouwenvelder, Johannes S.; Picioreanu, Cristian

    2016-01-01

    This study evaluates with numerical simulations supported by experimental data the impact of biofouling on membrane performance in a cross-flow forward osmosis (FO) system. The two-dimensional numerical model couples liquid flow with solute

  11. An experimental and modeling study of n-octanol combustion

    KAUST Repository

    Cai, Liming; Uygun, Yasar; Togbé , Casimir; Pitsch, Heinz G.; Olivier, Herbert; Dagaut, P.; Sarathy, Mani

    2015-01-01

    This study presents the first investigation on the combustion chemistry of n-octanol, a long chain alcohol. Ignition delay times were determined experimentally in a high-pressure shock tube, and stable species concentration profiles were obtained

  12. Experimental Study on the Langlee Wave Energy Converter

    DEFF Research Database (Denmark)

    Lavelle, John; Kofoed, Jens Peter

    This report concerns the experimental study of the 1:20 scale model of the Langlee Wave Energy Converter (WEC) carried out at Aalborg University’s wave basin during the summer of 2010.......This report concerns the experimental study of the 1:20 scale model of the Langlee Wave Energy Converter (WEC) carried out at Aalborg University’s wave basin during the summer of 2010....

  13. Experimental Studies of Hydrocarbon Flame Phenomena: Enabling Combustion Control

    Science.gov (United States)

    2016-07-30

    flames," Physics of Fluids , vol. 7, no. 6, pp. 1447-54, 1995. [8] K. Lyons, " Toward an understanding of the stabilization mechanisms of lifted...Experimental Studies of Hydrocarbon Flame Phenomena: Enabling Combustion Control This report summarizes the research accomplished in the project...34Experimental Studies of Hydrocarbon Flame Phenomena: Enabling Combustion Control". The main areas of activity are: a) electrostatic flame and flow

  14. Experimental study on the characteristics of semiconductor opening switch

    CERN Document Server

    Su Jian Cang; Ding Yong Zhong; Song Zhi Min; Ding Zhen Jie; Liu Guo Zhi

    2002-01-01

    An experimental set-up is developed to measure the characteristics of semiconductor opening switch (SOS). The parameters, such as interruption impedance, current int eruption time, voltage gain, pulse duration and energy transfer efficiency, are studied experimentally. The experimental results show that forward pumping time and reverse pumping time are important parameters for semiconductor opening switches. The influences of forward pumping time and reverse pumping time on interruption time, voltage gain, and energy transfer efficiency are obtained. In the interruption process, the impedance variation is divided into three phases: that is rapid increasing phase, slow change phase and completely interruption phase

  15. Using an experimental model for the study of therapeutic touch.

    Science.gov (United States)

    dos Santos, Daniella Soares; Marta, Ilda Estéfani Ribeiro; Cárnio, Evelin Capellari; de Quadros, Andreza Urba; Cunha, Thiago Mattar; de Carvalho, Emilia Campos

    2013-02-01

    to verify whether the Paw Edema Model can be used in investigations about the effects of Therapeutic Touch on inflammation by measuring the variables pain, edema and neutrophil migration. this is a pilot and experimental study, involving ten male mice of the same genetic strain and divided into experimental and control group, submitted to the chemical induction of local inflammation in the right back paw. The experimental group received a daily administration of Therapeutic Touch for 15 minutes during three days. the data showed statistically significant differences in the nociceptive threshold and in the paw circumference of the animals from the experimental group on the second day of the experiment. the experiment model involving animals can contribute to study the effects of Therapeutic Touch on inflammation, and adjustments are suggested in the treatment duration, number of sessions and experiment duration.

  16. Experimental Equipment for Physics Studies in the Aagesta Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bernander, G; Blomberg, P E; Dubois, P O

    1967-03-15

    Comprehensive physics measurements were carried out in connection with the start up of the Agesta reactor. For this purpose special experimental equipment was constructed and installed in the reactor. Parts of this were indispensable and/or time-saving for the reactivity control during the core build-up period and during the first criticality studies. This report gives mainly a detailed description of the experimental equipment used, but also the relevant physics background and the experience gained during the performance.

  17. A new dietary model to study colorectal carcinogenesis: experimental design, food preparation, and experimental findings.

    Science.gov (United States)

    Rozen, P; Liberman, V; Lubin, F; Angel, S; Owen, R; Trostler, N; Shkolnik, T; Kritchevsky, D

    1996-01-01

    Experimental dietary studies of human colorectal carcinogenesis are usually based on the AIN-76A diet, which is dissimilar to human food in source, preparation, and content. The aims of this study were to examine the feasibility of preparing and feeding rats the diet of a specific human population at risk for colorectal neoplasia and to determine whether changes in the colonic morphology and metabolic contents would differ from those resulting from a standard rat diet. The mean daily food intake composition of a previously evaluated adenoma patient case-control study was used for the "human adenoma" (HA) experimental diet. Foods were prepared as for usual human consumption and processed by dehydration to the physical characteristics of an animal diet. Sixty-four female Sprague-Dawley rats were randomized and fed ad libitum the HA or the AIN-76A diet. Every eight weeks, eight rats from each group were sacrificed, and the colons and contents were examined. Analysis of the prepared food showed no significant deleterious changes; food intake and weight gain were similar in both groups. Compared with the controls, the colonic contents of rats fed the HA diet contained significantly less calcium, concentrations of neutral sterols, total lipids, and cholic and deoxycholic acids were increased, and there were no colonic histological changes other than significant epithelial hyperproliferation. This initial study demonstrated that the HA diet can be successfully processed for feeding to experimental animals and is acceptable and adequate for growth but induces significant metabolic and hyperproliferative changes in the rat colon. This dietary model may be useful for studies of human food, narrowing the gap between animal experimentation and human nutritional research.

  18. Effects of a Classroom-Based Pre-Literacy Intervention for Preschoolers with Communication Disorders

    Science.gov (United States)

    Currier, Alyssa R.

    2013-01-01

    Children with communication disorders are often at risk of literacy difficulties, especially students that present with autism and/or speech sound disorders. This quasi-experimental study was designed to examine the effects of a 10-week "hybrid" intervention for preschool students with and without communication disorders in an integrated…

  19. Our experimental study of physiological modifications of densities

    International Nuclear Information System (INIS)

    Lamarque, J.L.; Bruel, J.M.; Dondelinger, R.; Vendrell, B.; Pelissier, O.; Rouanet, J.P.; Michel, J.L.; Bengana, H.; Levy, P.; Bruno, C.; Balmes, M.; Lopez, P.; Triby, X.

    1979-01-01

    Results of a comparative study performed with anatomical sections to identify the anatomical structures of the abdomen are presented. An experimental study consisted of an assay of a comparative study of densities performed on cadavers. An in vivo study consisted of a statistical study involving 278 cases of densitometric readings performed in hepatic, panreatic, renal parenchyma, splenic mesenchyma and several other tissues such as: fat, bones, muscles, spinal cord. (Auth.)

  20. Bridging the Gap from Classroom-based Learning to Experiential Professional Learning: A Hong Kong Case

    Directory of Open Access Journals (Sweden)

    Bertha Du-Babcock

    2016-12-01

    Full Text Available This paper describes and evaluates a funded longitudinal teaching development project that aims to bridge the gap from classroom-based theory learning to experiential professional learning, and thereby prepare ideal and competent world class graduates. To align with the University's shared mission to foster links with the business community, the design of the internship program has a threefold purpose and was implemented in stages. It intends to enhance students' professional awareness-knowledge-skills through a multi-leveled approach integrating classroom learning with professional practice. A debriefing mechanism was also built in enabling students to share their learning and professional challenges, and theory application to problem-solving scenarios. A 360 degree multiple evaluation procedure were used to measure the project effectiveness, including the use of industry consultants, student interns, hosts, and academic supervisors.   The project has proved to promote closer ties with the business community and enhance students' professional competencies to increase future success in the competitive job market. The impact of the internship program is significant in two aspects.  From the perspective of student learning, the internship allows students to understand how they can improve business efficiency by applying communications theories.  From the teaching perspective, the successful and unsuccessful intern experiences can be drawn upon in developing class-room teaching. These lessons can focus on preparing students to solve real-world business communication problems.

  1. What Shapes the Intention to Study Abroad? An Experimental Approach

    Science.gov (United States)

    Petzold, Knut; Moog, Petra

    2018-01-01

    In contrast to previous studies, this investigation aims to get deeper insights into the causes of the intention to study abroad by using an experimental approach. Although international experience is often considered as important, many students at German universities do not even consider abroad. Referring to the Theory of Rational Choice (RCT)…

  2. Infections in orthopaedic surgery : clinical and experimental studies

    NARCIS (Netherlands)

    Vogely, Henri Charles

    2000-01-01

    The diagnostic difficulties, variability in outcome and the heterogeinity of the problem of orthopaedic infections stimulated the author to a study of the literature, and several clinical and experimental studies. The diagnosis prosthesis-related infection can only be reached with an acceptable

  3. Pharmacological Experimental Study Of The Anti-Depressant Effect ...

    African Journals Online (AJOL)

    Pharmacological Experimental Study Of The Anti-Depressant Effect Of Total Saikosaponins. Y Liu, C Cao, H Ding. Abstract. Background: Chai Hu has the hepato-protective, choleretic, anti-tussive, analgesic, anti-inflammatory, anti-viral, hypotensive, hypolipidemic, and anti-tumor pharmacological effects. In this study, the ...

  4. Diffusion in liquids a theoretical and experimental study

    CERN Document Server

    Tyrrell, H J V

    1984-01-01

    Diffusion in Liquids: A Theoretical and Experimental Study aims to discuss the principles, applications, and advances in the field of diffusion, thermal diffusion, and thermal conduction in liquid systems. The book covers topics such as the principles of non-equilibrium thermodynamics; diffusion in binary and multicompetent systems; and experimental methods of studying diffusion processes in liquids. Also covered in the book are topics such as the theoretical interpretations of diffusion coefficients; hydrodynamic and kinetic theories; and diffusion in electrolyte systems. The text is recommen

  5. Analytical and Experimental Study of Residual Stresses in CFRP

    Directory of Open Access Journals (Sweden)

    Chia-Chin Chiang

    2013-01-01

    Full Text Available Fiber Bragg Grating sensors (FBGs have been utilized in various engineering and photoelectric fields because of their good environment tolerance. In this research, residual stresses of carbon fiber reinforced polymer composites (CFRP were studied using both experimental and analytical approach. The FBGs were embedded inside middle layers of CFRP to study the formation of residual stress during curing process. Finite element analysis was performed using ABAQUS software to simulate the CFRP curing process. Both experimental and simulation results showed that the residual stress appeared during cooling process and the residual stresses could be released when the CFRP was machined to a different shape.

  6. Experimental Setup For Study of Drop Deformation In Air Flow

    Directory of Open Access Journals (Sweden)

    Basalaev Sergey

    2017-01-01

    Full Text Available Experimental study for study of deformation of drops in air flow is considered. Experimental setup includes a module for obtaining the drops, an air flow system and measuring system. Module for formation of drops is in the form of vertically arranged dropper with capillary with the possibility of formation of fixed drops. Air flow supply system comprises an air pump coupled conduit through a regulating valve with a cylindrical pipe, installed coaxially with dropper. The measuring system includes the video camera located with possibility of visualization of drop and the Pitot gage for measurement of flow rate of air located in the output section of branch pipe. This experimental setup allows to provide reliable and informative results of the investigation of deformation of drops in the air flow.

  7. Histological study of rat masseter muscle following experimental occlusal alteration.

    Science.gov (United States)

    Nishide, N; Baba, S; Hori, N; Nishikawa, H

    2001-03-01

    It has been suggested that occlusal interference results in masticatory muscle dysfunction. In our previous study, occlusal interference reduced the rat masseter energy level during masticatory movements. The purpose of this study was to investigate the histological alterations of rat masseter muscles following experimental occlusal alteration with unilateral bite-raising. A total of eight male adult Wistar rats were equally divided into control and experimental groups. The experimental rats wore bite-raising splints on the unilateral upper molar. However, 4 weeks after the operation, the anterior deep masseter muscles were removed and then stained for succinic acid dehydrogenase (SDH), haematoxylin eosin (HE) and myofibrillar ATPase. Most of the muscle fibres in experimental rats remained intact, although partial histological changes were observed, such as extended connective tissue, appearance of inflammatory cells in the muscle fibres and existence of muscle fibres with central nuclei and central cores. Moreover, the fibre area-fibre frequency histograms of experimental muscle indicated a broad pattern than that of controls. These results indicated that occlusal interference caused histological changes in masseter muscles and that this may be related to the fact that the masseter energy level was reduced during masticatory movements in unilateral bite-raised rats.

  8. Experimental Study on a Rotor for WEPTOS Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Marchalot, Tanguy

    This report presents the results of an experimental study of the power conversion capabilities of one single rotor of the WEPTOS wave energy converter. The investigation focuses mainly on defining the optimal weight distribution in the rotor in order to improve the hydraulic performance through...

  9. Asymmetric modes in gyrotron tubes and their experimental study

    International Nuclear Information System (INIS)

    Garin, P.; Jedar, E.; Jendrzejczak, G.; mourier, G.; Payen, F.; Teyssier, L.

    1989-01-01

    High power gyrotron tubes suffer from the competition between oscillations on different modes of the resonant cavity. Different techniques for mode selection are outlined and the advantages of non symmetric modes are indicated. Their experimental study is described on a 100 GHz-200 kW - 100 ms - TE34 gyrotron. Some possible extrapolations are briefly presented. (author). 6 refs.; 4 figs

  10. An experimental study on effect of process parameters in deep ...

    African Journals Online (AJOL)

    The effects of various deep drawing process parameters were determined by experimental study with the use of Taguchi fractional factorial design and analysis of variance for AA6111 Aluminum alloy. The optimum process parameters were determined based on their influence on the thickness variation at different regions ...

  11. Experimental study on the double barrier structure at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, H Y; Chua, S J [Centre for Optoelectronics, Dept. of Electrical Engineering, National Univ. of Singapore (Singapore)

    1994-06-15

    An experimental study of AlAs / GaAs / AlAs double barrier structure is carried out. The double barrier and quantum well structure are grown by MBE. The peak-to-valley ratio 2.6 : 1 with peak current density of 1.6 kA/cm/sup 2 at room temperature have been achieved. (authors)

  12. Experimental study of the longitudinal instability for beam transport

    International Nuclear Information System (INIS)

    Reiser, M.; Wang, J.G.; Guo, W.M.; Wang, D.X.

    1990-01-01

    Theoretical model for beam longitudinal instability in a transport pipe with general wall impedance is considered. The result shows that a capacitive wall tends to stabilize the beam. The experimental study of the instability for a pure resistive-wall is presented, including the design parameters, setup and components for the experiment. 6 refs., 3 figs

  13. Future prospects of antiarrhythmic treatment based on experimental studies

    NARCIS (Netherlands)

    Janse, M. J.

    1995-01-01

    Based on recent experimental studies, a number of speculations about future developments are made regarding the treatment of atrial fibrillation, the problem of proarrhythmia in patients with heart failure, and the treatment of ventricular tachycardia developing during the first 6 weeks following

  14. Base flow and exhaust plume interaction. Part 1 : Experimental study

    NARCIS (Netherlands)

    Schoones, M.M.J.; Bannink, W.J.

    1998-01-01

    An experimental study of the flow field along an axi-symmetric body with a single operating exhaust nozzle has been performed in the scope of an investigation on base flow-jet plume interactions. The structure of under-expanded jets in a co-flowing supersonic free stream was described using

  15. Capillary microreactors for lactic acid extraction: experimental and modelling study

    NARCIS (Netherlands)

    Susanti, Susanti; Winkelman, Jozef; Schuur, Boelo; Heeres, Hero; Yue, Jun

    2015-01-01

    Lactic acid is an important biobased chemical and, among others, is used for the production of poly-lactic acid. Down-stream processing using state of the art technology is energy intensive and leads to the formation of large amounts of salts. In this presentation, experimental and modeling studies

  16. A new experimental study of charged K→3π decays

    International Nuclear Information System (INIS)

    Anikeev, V.; Bazilevskij, A.; Baehr, J.

    1998-01-01

    An experimental study was performed of the possibility to use an existing detector - the tagging station of the Tagged Neutrino Facility at IHEP, Serpukhov - for obtaining large statistics data on the decay K ± →π 0 π 0 π ± . After giving some motivation for this aim, preliminary results on Dalitz-plot slopes were presented

  17. Experimental and numerical study of an autonomous flap

    NARCIS (Netherlands)

    Bernhammer, L.O.; Navalkar, S.T.; Sodja, J.; De Breuker, R.; Karpel, M.

    2015-01-01

    This paper presents the experimental and numerical study of an autonomous load alleviation concept using trailing edge flaps. The flaps are autonomous units, which for instance can be used for gust load alleviation. The unit is self-powered and self-actuated through trailing edge tabs which are

  18. Computational and Experimental Studies on the Hetero-Diels-Alder ...

    African Journals Online (AJOL)

    NJD

    Additionally, experimental studies carried out on the reactions of these enaminones 1 with sulphene were also found to be in ... reactions of simple enaminoketones with some dienophiles have been ... example, the only reported [4+2] cycloaddition reaction of .... (2a–c, 3a–c) are true ground state minima, verified by second.

  19. Syntactic Enhancement and Second Language Literacy: An Experimental Study

    Science.gov (United States)

    Park, Youngmin; Warschauer, Mark

    2016-01-01

    This experimental study examined how the reading and writing development of sixth-grade L2 students was affected by syntactic enhancement. Visual-syntactic text formatting (VSTF) technology, which visualizes syntactic structures, was used to convert a textbook to the one with syntactic enhancement. The sample (n = 282), which was drawn from a…

  20. Results of Experimental Study on Flexitime and Family Life.

    Science.gov (United States)

    Winett, Richard A.; Neale, Michael S.

    1980-01-01

    According to two small experimental studies of flexible working hours, federal workers with young children choose to arrive at and depart from work earlier, allowing them to increase the time spent with their families and to engage in recreational, educational, and household activities. (Author/SK)

  1. Can Facebook Make Students Remember? An Experimental Study from Japan

    Science.gov (United States)

    Acar, Adam

    2014-01-01

    This study experimentally manipulated the way students submit their assignments and tested the number of new words that are learned in each condition. The results showed that students who submitted their assignments through Facebook learned as much as those who submitted their assignment in a traditional way. In the light of these findings, we can…

  2. Experimental study of liquid evaporation rate from coniferous biomass

    Directory of Open Access Journals (Sweden)

    Bulba E.E.

    2017-01-01

    Full Text Available The results of experimental studies of moisture evaporation from coniferous wood (spruce, pine are presented. The dependences of the mass evaporation rate on temperature and time are obtained. The calculation of the accommodation coefficient for the corresponding temperature ranges has been performed. The analysis of temperature regimes of drying of two typical coniferous wood species is carried out.

  3. Experimental study of spatial distribution of Ar glow discharge plasma

    International Nuclear Information System (INIS)

    Guo, X.M.; Zhou, T.D.; Pai, S.T.

    1996-01-01

    The characteristics of the spatial distribution of Ar glow discharge plasma were experimentally investigated. By means of direct comparisons between theory and experiment, the effects of the variation of gap separation, gas pressure, and electrode radius on the spatial distributions of electron density and electric field were studied. Results indicate that the maximum electron density moves toward the cathode as the gap separation or gas pressure increases while variation of electrode radius produces little effect. Predictions from a theoretical model have been experimentally verified. General agreements between theory and experiment were found to be reasonably good except in the cathode region, where discrepancy exists. copyright 1996 American Institute of Physics

  4. Experimental study of auxetic behavior of cellular structure

    Science.gov (United States)

    Chentsov, A. V.; Lisovenko, D. S.

    2018-04-01

    The uniaxial tension of two-dimensional auxetic cellular constructions is studied experimentally. Samples were made of nonauxetic polyethylene terephthalate (PET-A amorphous) and subjected to monotonous uniaxial tension until the last moment when they still remained plane. As a result of the experimental data analysis, comparison of the mechanical properties is given for a faultless sample and constructions in which one horizontal or vertical element in the central area of the sample was removed. It is shown that the lack of one horizontal element of the construction has little influence on the auxetic properties of these constructions unlike the structures with one vertical element being absent.

  5. An experimental study on cyclotron-Cherenkov radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C Y; Masuzaki, M; Yoshida, H; Toyosugi, N; Kamada, K; Ando, R [Kanazawa Univ. (Japan). Department of Physics

    1997-12-31

    Dielectric-loaded cylindrical waveguide configurations with an injected electron beam in which the growth rate of the cyclotron-Cherenkov instability surpasses that of the Cherenkov instability were sought by numerical treatment, and one configuration of this kind was found. This configuration consists of a metallic core and an outer metallic cylinder with a dielectric liner on the inner surface. Based on the calculations, an experimental device was designed and assembled to investigate experimentally radiation due to the cyclotron-Cherenkov instability. Beam propagation in the dielectric-loaded coaxial waveguide and microwave radiation due to the cyclotron-Cherenkov instability and the Cherenkov instability were studied. (author). 6 figs., 10 refs.

  6. Experimental study on beam for composite CES structural system

    Science.gov (United States)

    Matsui, Tomoya

    2017-10-01

    Development study on Concrete Encase Steel (CES) composite structure system has been continuously conducted toward the practical use. CES structure is composed of steel and fiber reinforced concrete. In previous study, it was found that CES structure has good seismic performance from experimental study of columns, beam - column joints, shear walls and a two story two span frame. However, as fundamental study on CES beam could be lacking, it is necessary to understand the structural performance of CES beam. In this study, static loading tests of CES beams were conducted with experimental valuable of steel size, the presence or absence of slab and thickness of slab. And restoring characteristics, failure behavior, deformation behavior, and strength evaluation method of CES beam were investigated. As the results, it was found that CES beam showed stable hysteresis behavior. Furthermore it was found that the flexural strength of the CES beam could be evaluated by superposition strength theory.

  7. Experimental study of curved guide tubes for pellet injection

    International Nuclear Information System (INIS)

    Combs, S.K.; Baylor, L.R.; Foust, C.R.; Gouge, M.J.; Jernigan, T.C.; Milora, S.L.

    1997-01-01

    The use of curved guide tubes for transporting frozen hydrogen pellets offers great flexibility for pellet injection into plasma devices. While this technique has been previously employed, an increased interest in its applicability has been generated with the recent ASDEX Upgrade experimental data for magnetic high-field side (HFS) pellet injection. In these innovative experiments, the pellet penetration appeared to be significantly deeper than for the standard magnetic low-field side injection scheme, along with corresponding greater fueling efficiencies. Thus, some of the major experimental fusion devices are planning experiments with HFS pellet injection. Because of the complex geometries of experimental fusion devices, installations with multiple curved guide tube sections will be required for HFS pellet injection. To more thoroughly understand and document the capability of curved guide tubes, an experimental study is under way at the Oak Ridge National Laboratory (ORNL). In particular, configurations and pellet parameters applicable for the DIII-D tokamak and the International Thermonuclear Experimental Reactor (ITER) were simulated in laboratory experiments. Initial test results with nominal 2.7- and 10-mm-diam deuterium pellets are presented and discussed

  8. Mechanical properties of jennite: A theoretical and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Juhyuk, E-mail: juhyuk.moon@stonybrook.edu [Civil Engineering Program, Department of Mechanical Engineering, Stony Brook University, NY 11794 (United States); Yoon, Seyoon [School of Engineering, Kings College, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Monteiro, Paulo J.M. [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States)

    2015-05-15

    The objective of this study is to determine the mechanical properties of jennite. To date, several hypotheses have been proposed to predict the structural properties of jennite. For the first time as reported herein, the isothermal bulk modulus of jennite was measured experimentally. Synchrotron-based high-pressure x-ray diffraction experiments were performed to observe the variation of lattice parameters under pressure. First-principles calculations were applied to compare with the experimental results and predict additional structural properties. Accurately measured isothermal bulk modulus herein (K{sub 0} = 64(2) GPa) and the statistical assessment on experimental and theoretical results suggest reliable mechanical properties of shear and Young's modulus, Poisson's ratio, and elastic tensor coefficients. Determination of these fundamental structural properties is the first step toward greater understanding of calcium–silicate–hydrate, as well as provides a sound foundation for forthcoming atomic level simulations.

  9. 1,2-Propanediol. Comprehensive experimental and theoretical study

    International Nuclear Information System (INIS)

    Verevkin, Sergey P.; Emel'yanenko, Vladimir N.; Nell, Gernot

    2009-01-01

    The standard (p 0 =0.1MPa) molar enthalpy of formation at the temperature 298.15 K of the liquid 1,2-propanediol was measured using combustion calorimetry. Molar enthalpies of vaporization of isomeric 1,2-propanediols were obtained from the temperature dependence of the vapor pressure measured by the transpiration method. Thermochemical investigations of 1,2-ethanediol and 1,2-propanediol available in the literature were collected and combined with own experimental results. This collection together with the new experimental results reported here has helped to resolve contradictions in the available sublimation enthalpies data and to recommend consistent and reliable set of vaporization and formation enthalpies for both diols under study. Ab initio calculations of gaseous molar enthalpy of formation of 1,2-ethanediol and 1,2-propanediol have been performed using the G3MP2 method and results are in excellent agreement with the selected experimental data.

  10. Experimental study and modeling of a novel magnetorheological elastomer isolator

    International Nuclear Information System (INIS)

    Yang, Jian; Li, Weihua; Sun, Shuaishuai; Du, Haiping; Li, Yancheng; Li, Jianchun; Deng, H X

    2013-01-01

    This paper reports an experimental setup aiming at evaluating the performance of a newly designed magnetorheological elastomer (MRE) seismic isolator. As a further effort to explore the field-dependent stiffness/damping properties of the MRE isolator, a series of experimental testing were conducted. Based upon the analysis of the experimental responses and the characteristics of the MRE isolator, a new model that is capable of reproducing the unique MRE isolator dynamics behaviors is proposed. The validation results verify the model’s effectiveness to portray the MRE isolator. A study on the field-dependent parameters is then provided to make the model valid with fluctuating magnetic fields. To fully explore the mechanism of the proposed model, an investigation relating the dependence of the proposed model on every parameter is carried out. (technical note)

  11. Experimental asbestos studies in the UK: 1912-1950.

    Science.gov (United States)

    Greenberg, Morris

    2017-11-01

    The asbestos industry originated in the UK in the 1870s. By 1898, asbestos had many applications and was reported to be one of the four leading causes of severe occupational disease. In 1912, the UK government sponsored an experimental study that reported that exposure to asbestos produced no more than a modicum of pulmonary fibrosis in guinea pigs. In the 1930s, the newly established Medical Research Council, with assistance from industry, sponsored a study of the effects of exposing animals to asbestos by injection (intratracheal and subcutaneous) and by inhalation in the factory environment. Government reports, publications, and contemporary records obtained by legal discovery have been reviewed in the context of the stage of scientific development and the history of the times. Experimenters were engaged in a learning process during the 1912-1950 period, and their reports of the effects of asbestos were inconsistent. Pathologists who studied the effects of asbestos experimentally, at whole animal, tissue and cellular levels, advanced experimental methodology and mechanistic knowledge. In the hands of public relations experts, however, research was exploited to preserve an industry and perpetuate preventable diseases, a practice that continues to this day. © 2017 Wiley Periodicals, Inc.

  12. Numerical and experimental study of two turbulent opposed plane jets

    Energy Technology Data Exchange (ETDEWEB)

    Besbes, Sonia; Mhiri, Hatem [Laboratoire de Mecanique des Fluides et Thermique, Ecole Nationale d' Ingenieurs de Monastir, Route de Ouardanine, Monastir (Tunisia); Le Palec, Georges; Bournot, Philippe [Institut de Mecanique de Marseille, UNIMECA, Technopole de Chateau-Gombert, 60 rue Joliot-Curie, 13453 Marseille (France)

    2003-09-01

    The turbulent interaction between two opposed plane jets separated by a distance H is experimentally studied by using a PIV (Particle Image Velocimetry) method and numerically investigated by means of a finite volume code. Two turbulence models have been tested: the standard k-{epsilon} model and a second-order model. The validation of the numerical study was performed by comparing the results with experimental data obtained for the case of two interacting opposed jets at ambient temperature (isothermal case). The effect of the angle of inclination of the jets is studied. Conclusions of the validation are then used to study the interaction between two jets, one being maintained at ambient temperature whereas the other is heated. Results show that the stagnation point moves towards the heated jet. It is shown that the heating induces a stabilizing effect on the flow. (orig.)

  13. Experimental study of modification of neutron spectrum using filters

    International Nuclear Information System (INIS)

    Kobayashi, H.; Matsubayashi, M.; Brenizer, J.S. Jr.; Lindsay, J.T.

    1996-01-01

    Filter effects for continuum thermal neutron beams were experimentally studied by means of an effective energy. Be, Bi and Pb were used as filter materials to examine the energy shift of the spectrum. It was found that the effective energy of a thermal neutron beam is easily lowered into a sub-thermal region (down to 10 meV) by use of a filter system without any cooling system. The effectiveness and its applicability will be discussed in this study. (orig.)

  14. Design study of blanket structure for tokamak experimental fusion reactor

    International Nuclear Information System (INIS)

    1979-11-01

    Design study of the blanket structure for JAERI Experimental Fusion Reactor (JXFR) has been carried out. Studied here were fabrication and testing of the blanket structure (blanket cells, blanket rings, piping and blanket modules), assembly and disassembly of the blanket module, and monitering and testing technique. Problems in design and fabrication of the blanket structure could be revealed. Research and development problems for the future were also disclosed. (author)

  15. Experimental and theoretical study of heterogeneous iron precipitation in silicon

    OpenAIRE

    Haarahiltunen, Antti; Väinölä, Hele; Anttila, O.; Yli-Koski, Marko

    2007-01-01

    Heterogeneous iron precipitation in silicon was studied experimentally by measuring the gettering efficiency of oxide precipitate density of 1×10exp10cm−3. The wafers were contaminated with varying iron concentrations, and the gettering efficiency was studied using isothermal annealing in the temperature range from 300 to 780°C. It was found that iron precipitation obeys the so called s-curve behavior: if iron precipitation occurs, nearly all iron is gettered. For example, after 30 min anneal...

  16. experimental study of cement grout: rheological behavior and sedimentation

    OpenAIRE

    Rosquoët , Frédéric; Alexis , Alain ,; Khelidj , Abdelhafid; Phelipot-Mardelé , Annabelle

    2002-01-01

    International audience; Three basic elements (cement, water and admixture) usually make up injectable cement grouts used for prestressed cable coating, repair and consolidation of masonry, soil grouting, etc... The present study was divided into two parts. First, in order to characterize rheologically fresh cement paste with W/C ratios (water/cement ratio) varying between 0.35 and 1, an experimental study was carried out and has revealed that the cement past behaves like a shear-thinning mate...

  17. Experimental and Analytical Studies of Solar System Chemistry

    Science.gov (United States)

    Burnett, Donald S.

    2003-01-01

    The cosmochemistry research funded by this grant resulted in the publications given in the attached Publication List. The research focused in three areas: (1) Experimental studies of trace element partitioning. (2) Studies of the minor element chemistry and O isotopic compositions of MgAlO4 spinels from Ca-Al-Rich Inclusions in carbonaceous chondrite meteorites, and (3) The abundances and chemical fractionations of Th and U in chondritic meteorites.

  18. Experimental Studies of the Transport Parameters of Warm Dense Matter

    Energy Technology Data Exchange (ETDEWEB)

    Chouffani, Khalid [Idaho State Univ., Pocatello, ID (United States)

    2014-12-01

    There is a need to establish fundamental properties of matter and energy under extreme physical conditions. Although high energy density physics (HEDP) research spans a wide range of plasma conditions, there is one unifying regime that is of particular importance and complexity: that of warm dense matter, the transitional state between solid state condensed matter and energetic plasmas. Most laboratory experimental conditions, including inertial confinement implosion, fall into this regime. Because all aspects of laboratory-created high-energy-density plasmas transition through the warm dense matter regime, understanding the fundamental properties to determine how matter and energy interact in this regime is an important aspect of major research efforts in HEDP. Improved understanding of warm dense matter would have significant and wide-ranging impact on HEDP science, from helping to explain wire initiation studies on the Sandia Z machine to increasing the predictive power of inertial confinement fusion modeling. The central goal or objective of our proposed research is to experimentally determine the electrical resistivity, temperature, density, and average ionization state of a variety of materials in the warm dense matter regime, without the use of theoretical calculations. Since the lack of an accurate energy of state (EOS) model is primarily due to the lack of experimental data, we propose an experimental study of the transport coefficients of warm dense matter.

  19. An Experimental and numerical Study for squeezing flow

    Science.gov (United States)

    Nathan, Rungun; Lang, Ji; Wu, Qianhong; Vucbmss Team

    2017-11-01

    We report an experimental and numerical study to examine the transient squeezing flow driven by sudden external impacts. The phenomenon is widely observed in industrial applications, e.g. squeeze dampers, or in biological systems, i.e. joints lubrication. However, there is a lack of investigation that captures the transient flow feature during the process. An experimental setup was developed that contains a piston instrumented with a laser displacement sensor and a pressure transducer. The heavy piston was released from rest, creating a fast compaction on the thin fluid gap underneath. The motion of the piston and the fluid pressure build-up was recorded. For this dynamic process, a CFD simulation was performed which shows excellent agreement with the experimental data. Both the numerical and experimental results show that, the squeezing flow starts with the inviscid limit when the viscous fluid effect has no time to appear, and thereafter becomes a developing flow, in which the inviscid core flow region decreases and the viscous wall region increases until the entire fluid gap is filled with viscous fluid flow. The study presented herein, filling the gap in the literature, will have broad impacts in industrial and biomedical applications. This research was supported by the National Science Foundation under Award 1511096, and supported by the Seed Grant from The Villanova Center for the Advancement of Sustainability in Engineering (VCASE).

  20. Experimental and numerical studies in a vortex tube

    International Nuclear Information System (INIS)

    Sohn, Chang Hyun; Kim, Chang Soo; Gowda, B. H. L Lakshmana; Jung, Ui Hyun

    2006-01-01

    The present investigation deals with the study of the internal flow phenomena of the counter-flow type vortex tube using experimental testing and numerical simulation. Visualization was carried out using the surface tracing method, injecting dye on the vortex tube wall using a needle. Vortex tube is made of acrylic to visualize the surface particle tracing and the input air pressure was varied from 0.1 MPa to 0.3 MPa. The experimentally visualized results on the tube show that there is an apparent sudden changing of the trajectory on the vortex tube wall which was observed in every experimental test case. This may indicate the stagnation position of the vortex flow. The visualized stagnation position moves towards the vortex generator with increase in cold flow ratio and input pressure. Three-dimensional computational study is also conducted to obtain more detailed flow information in the vortex tube. Calculated total pressure, static pressure and total temperature distributions in the vortex tube were in good agreement with the experimental data. The computational particle trace on the vortex tube wall is very similar to that observed in experiments

  1. Experimental study of elementary collection efficiency of aerosols by spray: Design of the experimental device

    Energy Technology Data Exchange (ETDEWEB)

    Ducret, D.; Vendel, J.; Garrec. S.L.

    1995-02-01

    The safety of a nuclear power plant containment building, in which pressure and temperature could increase because of a overheating reactor accident, can be achieved by spraying water drops. The spray reduces the pressure and the temperature levels by condensation of steam on cold water drops. The more stringent thermodynamic conditions are a pressure of 5.10{sup 5} Pa (due to steam emission) and a temperature of 413 K. Moreover its energy dissipation function, the spray leads to the washout of fission product particles emitted in the reactor building atmosphere. The present study includes a large program devoted to the evaluation of realistic washout rates. The aim of this work is to develop experiments in order to determine the collection efficiency of aerosols by a single drop. To do this, the experimental device has to be designed with fundamental criteria:-Thermodynamic conditions have to be representative of post-accident atmosphere. Thermodynamic equilibrium has to be attained between the water drops and the gaseous phase. Thermophoretic, diffusiophoretic and mechanical effects have to be studied independently. Operating conditions have to be homogenous and constant during each experiment. This paper presents the design of the experimental device. In practice, the consequences on the design of each of the criteria given previously and the necessity of being representative of the real conditions will be described.

  2. Experimental and Theoretical Studies in Hydrogen-Bonding Organocatalysis

    Directory of Open Access Journals (Sweden)

    Matej Žabka

    2015-08-01

    Full Text Available Chiral thioureas and squaramides are among the most prominent hydrogen-bond bifunctional organocatalysts now extensively used for various transformations, including aldol, Michael, Mannich and Diels-Alder reactions. More importantly, the experimental and computational study of the mode of activation has begun to attract considerable attention. Various experimental, spectroscopic and calculation methods are now frequently used, often as an integrated approach, to establish the reaction mechanism, the mode of activation or explain the stereochemical outcome of the reaction. This article comprises several case studies, sorted according to the method used in their study. The aim of this review is to give the investigators an overview of the methods currently utilized for mechanistic investigations in hydrogen-bonding organocatalysis.

  3. Experimental study of flame stability in biogas premix system

    International Nuclear Information System (INIS)

    Diaz G, Carlos A; Amell A Andres; Cardona Luis F

    2008-01-01

    Utilization of new renewable energy sources have had a special interest in last years looking for decrease the dependence of fossil fuels and the environmental impact generated for them. This work studies experimentally the flame stability of a simulated biogas with a volumetric composition of 60% methane and 40% carbon dioxide. The objective of this study is to obtain information about design and interchangeability of gases in premixed combustion systems that operate with different fuel gases. The critical velocity gradient was the stability criteria used. Utilization of this criteria and the experimental method followed, using a partial premixed burner, stability flame diagram of biogas studied had been obtained. Presence of carbon dioxide has a negative effect in flame stability, decreasing significantly the laminar flame speed and consequently, the stability range of biogas burners because of apparition of blow off.

  4. Experimental and analytical studies of high heat flux components for fusion experimental reactor

    International Nuclear Information System (INIS)

    Araki, Masanori

    1993-03-01

    In this report, the experimental and analytical results concerning the development of plasma facing components of ITER are described. With respect to developing high heat removal structures for the divertor plates, an externally-finned swirl tube was developed based on the results of critical heat flux (CHF) experiments on various tube structures. As the result, the burnout heat flux, which also indicates incident CHF, of 41 ± 1 MW/m 2 was achieved in the externally-finned swirl tube. The applicability of existing CHF correlations based on uniform heating conditions was evaluated by comparing the CHF experimental data with the smooth and the externally-finned tubes under one-sided heating condition. As the results, experimentally determined CHF data for straight tube show good agreement, for the externally-finned tube, no existing correlations are available for prediction of the CHF. With respect to the evaluation of the bonds between carbon-based material and heat sink metal, results of brazing tests were compared with the analytical results by three dimensional model with temperature-dependent thermal and mechanical properties. Analytical results showed that residual stresses from brazing can be estimated by the analytical three directional stress values instead of the equivalent stress value applied. In the analytical study on the separatrix sweeping for effectively reducing surface heat fluxes on the divertor plate, thermal response of the divertor plate has been analyzed under ITER relevant heat flux conditions and has been tested. As the result, it has been demonstrated that application of the sweeping technique is very effective for improvement in the power handling capability of the divertor plate and that the divertor mock-up has withstood a large number of additional cyclic heat loads. (J.P.N.) 62 refs

  5. The Effectiveness of Hypnosis Intervention for Labor: An Experimental Study.

    Science.gov (United States)

    Beevi, Zuhrah; Low, Wah Yun; Hassan, Jamiyah

    2017-10-01

    Hypnosis has been shown to help pregnant women experience improved labor and postpartum periods. The present study compares the differences between experimental (n = 23) and control groups (n = 22) on specific variables measured both during labor and 24 hr postpartum. The participants in the experimental group received the hypnosis intervention at weeks 16, 20, 28, and 36 of pregnancy, while those in the control group received only routine antenatal care. The data collected at the labor stage describe the length of the labor stage, pain relief used during labor, the method of delivery, and the type of assisted vaginal delivery. Within 24 hr of delivery, data on neonatal birth weight, neonatal Apgar scores, and self-reported pain were obtained. The labor stage results showed no significant differences in the length of the second and third stages of labor. Although the participants in the experimental group reported higher pain levels immediately prior to, during, and immediately after delivery, their use of pethidine during labor was significantly lower than the control group participants. None of the experimental group participants opted for an epidural, and they had a greater number of assisted vaginal deliveries than the control group participants. The 24 hr postpartum results showed that the neonates of the experimental group participants had nonsignificantly higher Apgar scores than those of the women in the control group. Group differences in neonatal weight were not significant. The results of the present study indicate that hypnosis is useful for assisting pregnant women during labor and the postpartum period.

  6. Experimental study of Coal Pyrolysis 2.: Experimental characterisation of volatile matter

    International Nuclear Information System (INIS)

    Hugony, F.; Migliavacca, G.

    2008-01-01

    In this paper considerations about experiments conducted through T G-Ftir are reported, in order to study the gas composition coming from coal pyrolysis. In particular qualitative and semi-qualitative evaluation of hydrocarbon evolution rate, as CH4, C2H4 and C3H6 are reported. It has been observed a strict relation between the evolution rate of the listed compounds, the coal rank and their elementary composition. The reported data constitute a good support to the validation of the predictive models of coal devolatilization. To complete the study two papers will be published in the next months: one containing experimental data from pyrolysis process in a fixed bed reactor and another one concerning the NMR analysis of the produced char. [it

  7. Experimental Study of Impregnation Birch and Aspen Samples

    Directory of Open Access Journals (Sweden)

    Igor Vladislavovich Grigorev

    2014-10-01

    Full Text Available An experimental study of wood impregnation was implemented by applying centrifugal methods. The impregnants were a 10% aqueous solution of potassium chloride and a 2% aqueous solution of borax. Birch (Betula pendula and aspen (Populus tremula wood samples in different moisture content were tested. The impregnation time in the centrifugal device were 30 seconds repeated 21 times, and the samples were measured after every 30 seconds. The experimental results were fitted to a nonlinear filtration law, which indicated that the centrifugal wood impregnation was dependent on wood species, wood moisture, rotational speed, and radius. Determination of rotational speed and centrifuge radius for impregnating aspen and birch at varying lengths and humidity under conditions of the nonlinear impregnant filtration law can be done using the example charts that were developed and presented in this study.

  8. Lung Morphological Changes in Closed Chest Injury (an experimental study

    Directory of Open Access Journals (Sweden)

    A. M. Golubev

    2012-01-01

    Full Text Available Objective: to study lung morphological changes in a closed chest injury model in laboratory animals. Material and methods. Experiments were carried out in 30 male albino nonbred rats weighing 350—380 g. Closed chest injury was simulated, by exposing the chest of anesthetized rats to a 300-g metal cylinder falling from a height of 30 cm. The observation periods were 1, 3, 6, and 24 hours. Results. The signs of evident perivenular edema that was uncharas-teristic to acute respiratory distress syndrome induced by other causes are an important peculiarity of lung morphological changes in this experimental model of closed chest injury. Conclusion. The experimental studies clarified the pattern of lung morphological changes in the early period after closed chest injury. Key words: closed chest injury, pulmonary edema.

  9. Experimental study of particulate fouling onto heat exchanger elements

    International Nuclear Information System (INIS)

    Chandrasa

    1994-01-01

    An experimental study of particulate fouling onto tubular heat exchanger surfaces was carried out using sodium sulfate particles. An experimental apparatus equipped with an aerosol generator has been used to examine the deposition of small particles under controlled conditions. Two sets of experiments were performed. Firstly, the deposition against time of solid particles onto single heat exchanger tube in cross-flow was studied. The effects of a number variables such as particle size, gas velocity and temperature on the deposition was analysed. Secondly, the deposition for the aerosol particles as they passed through a bank of finned tubes was examined. The deposition patterns on various tubes depended on local conditions (velocity and temperature) within the bank. It was found that the fouling resistance increases as aerosol flow rate decreases. The smaller particles showed higher fouling resistance. (author) [fr

  10. An Experimental Study of a Pulsed Electromagnetic Plasma Accelerator

    Science.gov (United States)

    Thio, Y. C. Francis; Eskridge, Richard; Lee, Mike; Smith, James; Martin, Adam; Markusic, Tom E.; Cassibry, Jason T.; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    Experiments are being performed on the NASA Marshall Space Flight Center (MSFC) pulsed electromagnetic plasma accelerator (PEPA-0). Data produced from the experiments provide an opportunity to further understand the plasma dynamics in these thrusters via detailed computational modeling. The detailed and accurate understanding of the plasma dynamics in these devices holds the key towards extending their capabilities in a number of applications, including their applications as high power (greater than 1 MW) thrusters, and their use for producing high-velocity, uniform plasma jets for experimental purposes. For this study, the 2-D MHD modeling code, MACH2, is used to provide detailed interpretation of the experimental data. At the same time, a 0-D physics model of the plasma initial phase is developed to guide our 2-D modeling studies.

  11. A Combined Theoretical and Experimental Study for Silver Electroplating

    Science.gov (United States)

    Liu, Anmin; Ren, Xuefeng; An, Maozhong; Zhang, Jinqiu; Yang, Peixia; Wang, Bo; Zhu, Yongming; Wang, Chong

    2014-01-01

    A novel method combined theoretical and experimental study for environmental friendly silver electroplating was introduced. Quantum chemical calculations and molecular dynamic (MD) simulations were employed for predicting the behaviour and function of the complexing agents. Electronic properties, orbital information, and single point energies of the 5,5-dimethylhydantoin (DMH), nicotinic acid (NA), as well as their silver(I)-complexes were provided by quantum chemical calculations based on density functional theory (DFT). Adsorption behaviors of the agents on copper and silver surfaces were investigated using MD simulations. Basing on the data of quantum chemical calculations and MD simulations, we believed that DMH and NA could be the promising complexing agents for silver electroplating. The experimental results, including of electrochemical measurement and silver electroplating, further confirmed the above prediction. This efficient and versatile method thus opens a new window to study or design complexing agents for generalized metal electroplating and will vigorously promote the level of this research region.

  12. A Combined Theoretical and Experimental Study for Silver Electroplating

    Science.gov (United States)

    Liu, Anmin; Ren, Xuefeng; An, Maozhong; Zhang, Jinqiu; Yang, Peixia; Wang, Bo; Zhu, Yongming; Wang, Chong

    2014-01-01

    A novel method combined theoretical and experimental study for environmental friendly silver electroplating was introduced. Quantum chemical calculations and molecular dynamic (MD) simulations were employed for predicting the behaviour and function of the complexing agents. Electronic properties, orbital information, and single point energies of the 5,5-dimethylhydantoin (DMH), nicotinic acid (NA), as well as their silver(I)-complexes were provided by quantum chemical calculations based on density functional theory (DFT). Adsorption behaviors of the agents on copper and silver surfaces were investigated using MD simulations. Basing on the data of quantum chemical calculations and MD simulations, we believed that DMH and NA could be the promising complexing agents for silver electroplating. The experimental results, including of electrochemical measurement and silver electroplating, further confirmed the above prediction. This efficient and versatile method thus opens a new window to study or design complexing agents for generalized metal electroplating and will vigorously promote the level of this research region. PMID:24452389

  13. Experimental study of optical fibers influence on composite

    Science.gov (United States)

    Liu, Rong-Mei; Liang, Da-Kai

    2010-03-01

    Bending strength and elasticity modulus of composite, with and without embedded optical fibers, were experimentally studied. Two kinds of laminates, which were denoted as group 1 and group 2, were fabricated from an orthogonal woven glass/epoxy prepreg. Since the normal stress value becomes the biggest at the surface of a beam, the optical fibers were embedded at the outmost layer and were all along the loading direction. Four types of materials, using each kind of laminated prepreg respectively, were manufactured. The embedded optical fibers for the 4 material types were 0, 10, 30 and 50 respectively. Three-point bending tests were carried out on the produced specimens to study the influence of embedded optical fiber on host composite. The experimental results indicated that the materials in group 2 were more sensitive to the embedded optical fibers.

  14. Manipulating Task Implementation Variables with Incipient Spanish Language Learners: A Classroom-Based Study

    Science.gov (United States)

    Payant, Caroline; Reagan, Derek

    2018-01-01

    A growing body of research has shown a positive role of task-supported instruction in second language (L2) learning (Ellis, 2003a; Loewen, 2015; Van Den Branden, 2006). From a pedagogical perspective, recycling or repeating parts of teaching materials is common practice and theoretical support for such practice is emerging (Bygate and Samuda,…

  15. A theoretical and experimental study of microshield circuits

    Science.gov (United States)

    Dib, Nihad I.; Drayton, Rhonda F.; Katehi, Linda P. B.

    1993-05-01

    The novel type of monolithic planar transmission line presently studied theoretically and experimentally operates without via-holes or ground-equalizing air bridges; it also radiates less than conventional coplanar waveguides and furnishes a wide range of impedances in virtue of its many design parameters. The space-domain integral equation method is used to analyze several discontinuities of the proposed line. It is shown that the proposed line discontinuities radiate less than the corresponding coplanar waveguide cases.

  16. Transformation induced plasticity in maraging steel: an experimental study

    International Nuclear Information System (INIS)

    Nagayama, K.; Kitajima, Y.; Kigami, S.; Tanaka, K.

    2000-01-01

    The deformation behavior of a maraging TRIP (transformation induced plasticity) steel (MAVAL X12) is studied experimentally under a constant load. The existence of the back stress in the axial direction is directly proved by investigating the dilatation curves. Martensite-start lines are given under tensile, compressive and shear stresses. The evolution of TRIP strain and the maximum TRIP strain are determined. The alloy response during isothermal tensile test is explained in terms of influences both by the composite and transformation. (orig.)

  17. Studies of the experimental technologies of radiative opacity

    International Nuclear Information System (INIS)

    Zhang Jiyan; Yang Guohong; Ding Yaonan; Yang Jiamin; Li Jun; Zhang Wenhai; He Yingling; Wang Yaomei; Huang Haodong

    2004-12-01

    On the SHENGUANG-II laser facility, integrated experiment for opacity measurement was performed and related physical items were studies. In the experiment, some new-typed diagnosing device were also tested. The experiment includes three contents: (1) Investigation of the measurement technique of absorption spectra in the keV region; (2) Investigation of the measurement technique of dual point projection spectroscopy; (3) Investigation of the temperature and density parameters of the experimental samples. (authors)

  18. Experimental Study on Noise Characteristic of Centrifugal Compressor Surge

    OpenAIRE

    Yang, Qichao; Zhao, Yuanyang; SHU, Yue; LI, Xiaosa; LI, Liansheng

    2016-01-01

    The centrifugal air compressor test rig is was designed and established. The experimental study was carried out on the surge characteristics of centrifugal compressor including the pressure in the pipe and the noise characteristics under different rotation speed. The tested results showed that both the suction pressure and discharge pressure fluctuation increase under surge condition and the amplitude of discharge pressure fluctuation is significantly higher than that of suction pressure. In ...

  19. Microneural anastomosis with fibrin glue : an experimental study.

    OpenAIRE

    Suri A; Mehta V; Sarkar C

    2002-01-01

    An experimental study was designed to compare the histological analysis of nerve anastomosis with 10-0 microsurgical sutures and fibrin adhesive. Wistar albino rats′ sciatic nerves were transected and repaired either with fibrin adhesive-Beriplast P (M/s Centeon-Cadila Health Care) or with 10-0 monofilament microsutures. Histological assessment was performed at 10, 20, 30, 60 and 90 days after surgery. Functional recovery of the sciatic nerves started at two months and was near normal ...

  20. Respecifying lab ethnography an ethnomethodological study of experimental physics

    CERN Document Server

    Sormani, Philippe

    2014-01-01

    Respecifying Lab Ethnography delivers the first ethnomethodological study of current experimental physics in action, describing the disciplinary orientation of lab work and exploring the discipline in its social order, formal stringency and skilful performance - in situ and in vivo. In bringing together two major strands of ethnomethodological inquiry, reflexive ethnography and video analysis, which have hitherto existed in parallel, Respecifying Lab Ethnography introduces a practice-based video analysis. In doing so, the book recasts conventional distinctions to shed fresh light on methodolog

  1. Experimental study of hydrogen jet ignition and jet extinguishment

    International Nuclear Information System (INIS)

    Wierman, R.W.

    1979-04-01

    Two phases are described of an experimental study that investigated: (1) the ignition characteristics of hydrogen--sodium jets, (2) the formation of hydrogen in sodium--humid air atmospheres, and (3) the extinguishment characteristics of burning hydrogen--sodium jets. Test conditions were similar to those postulated for highly-improbable breeder reactor core melt-through accidents and included: jet temperature, jet velocity, jet hydrogen concentration, jet sodium concentration, atmospheric oxygen concentration, and atmospheric water vapor concentration

  2. Experimental study of possible therapy of the acute radiation syndrome

    International Nuclear Information System (INIS)

    Willborn, M.

    1981-01-01

    These experimental studies showed that the survival time of rats, irradiated in a whole-body irradiation with 3000 rad 60 Co-gamma, can be positively influenced by the administration of an antibiotic and also by glucocorticoids. Contrary to our expectations, the combined application of the glucocorticoid and the antibiotic did not increase the survival time of the animals with gastrointestinal syndromes compared with the exclusive administration of the antibiotic. The mineral corticoid aldosterone resulted to be ineffective. (orig.) [de

  3. Experimental studies of radiation carcinogenesis in the skin: a review

    International Nuclear Information System (INIS)

    Coggle, J.E.; Williams, J.P.

    1990-01-01

    Dose and time response characteristics of cancer induction following a variety of modes and qualities of radiation exposure are reviewed in relation to rat and mouse skin studies. Despite interspecies differences, it is shown that all of the experimental data for radiogenic skin cancer, when expressed per unit area of skin, fall on a relatively narrow and well defined response curve, which is approximately two orders of magnitude more sensitive than the human skin cancer dose response. (UK)

  4. Elise: a new facility for unprecedented experimental nuclear fission studies

    International Nuclear Information System (INIS)

    Taieb, J.; Belier, G.; Chatillon, A.; Granier, T.; Kelic, A.; Ricciardi, V.; Schmidt, K.H.; Voss, B.; Coste-Delclaux, M.; Diop, C.; Jouanne, C.; Schmitt, C.; Aiche, M.; Czajkowski, S.; Jurado, B.; Audouin, L.; Peyre, J.; Rosier, P.; Tassan-Got, L.; Bertoumieux, E.; Dore, D.; Dupont, E.; Letourneau, A.; Panebianco, S.

    2009-01-01

    A novel experimental program aiming to study the properties of fragments and neutrons emitted in the fission process has been initiated. The experiment will be held at the ELISe electron-ion collider to be constructed at GSI, Darmstadt in the framework of the FAIR extension of the facility. The experiment will take advantage of the inverse kinematics allowing, in particular, a total mass and charge resolution for all fission fragments. (authors)

  5. Experimental study on convective heat transfer with thin porous bodies

    International Nuclear Information System (INIS)

    Nishi, Yoshihisa; Kinoshita, Izumi; Furuya, Masahiro

    2001-01-01

    Experimental studies are made on the convective heat transfer of three types of thin porous bodies. Heat transfer performances, flow patterns and temperature profiles near the porous bodies are compared with each other. The heat transfer performance of porous bodies with the largest pore diameter is large. It became clear that the high heat transfer performance depends on an excellent heat transportation ability inside the pore and near the surface of the porous bodies. (author)

  6. Computational/experimental studies of isolated, single component droplet combustion

    Science.gov (United States)

    Dryer, Frederick L.

    1993-01-01

    Isolated droplet combustion processes have been the subject of extensive experimental and theoretical investigations for nearly 40 years. The gross features of droplet burning are qualitatively embodied by simple theories and are relatively well understood. However, there remain significant aspects of droplet burning, particularly its dynamics, for which additional basic knowledge is needed for thorough interpretations and quantitative explanations of transient phenomena. Spherically-symmetric droplet combustion, which can only be approximated under conditions of both low Reynolds and Grashof numbers, represents the simplest geometrical configuration in which to study the coupled chemical/transport processes inherent within non-premixed flames. The research summarized here, concerns recent results on isolated, single component, droplet combustion under microgravity conditions, a program pursued jointly with F.A. Williams of the University of California, San Diego. The overall program involves developing and applying experimental methods to study the burning of isolated, single component droplets, in various atmospheres, primarily at atmospheric pressure and below, in both drop towers and aboard space-based platforms such as the Space Shuttle or Space Station. Both computational methods and asymptotic methods, the latter pursued mainly at UCSD, are used in developing the experimental test matrix, in analyzing results, and for extending theoretical understanding. Methanol, and the normal alkanes, n-heptane, and n-decane, have been selected as test fuels to study time-dependent droplet burning phenomena. The following sections summarizes the Princeton efforts on this program, describe work in progress, and briefly delineate future research directions.

  7. Spent Fuel Transportation Package Performance Study - Experimental Design Challenges

    International Nuclear Information System (INIS)

    Snyder, A. M.; Murphy, A. J.; Sprung, J. L.; Ammerman, D. J.; Lopez, C.

    2003-01-01

    Numerous studies of spent nuclear fuel transportation accident risks have been performed since the late seventies that considered shipping container design and performance. Based in part on these studies, NRC has concluded that the level of protection provided by spent nuclear fuel transportation package designs under accident conditions is adequate. [1] Furthermore, actual spent nuclear fuel transport experience showcase a safety record that is exceptional and unparalleled when compared to other hazardous materials transportation shipments. There has never been a known or suspected release of the radioactive contents from an NRC-certified spent nuclear fuel cask as a result of a transportation accident. In 1999 the United States Nuclear Regulatory Commission (NRC) initiated a study, the Package Performance Study, to demonstrate the performance of spent fuel and spent fuel packages during severe transportation accidents. NRC is not studying or testing its current regulations, a s the rigorous regulatory accident conditions specified in 10 CFR Part 71 are adequate to ensure safe packaging and use. As part of this study, NRC currently plans on using detailed modeling followed by experimental testing to increase public confidence in the safety of spent nuclear fuel shipments. One of the aspects of this confirmatory research study is the commitment to solicit and consider public comment during the scoping phase and experimental design planning phase of this research

  8. Combustion behaviour of pulverised wood - Numerical and experimental studies

    Energy Technology Data Exchange (ETDEWEB)

    Lixin Tao [TPS Termiska Processer AB, Nykoeping (Sweden)

    2002-05-01

    This report presents the experimental results achieved in an on-going project financed by STEM (Energimyndigheten) within the research program 'Gasification and combustion of solid fuels', during the first phase of the project (2001-03-05 to 2002-03-05). The project is a collaboration project between LTH and TPS on combined numerical modelling/experimental investigation on combustion of pulverised wood. Particularly TPS carry out the experimental investigation in a laboratory vertical furnace. During the project, the experimental rig has been developed. The experimental furnace has an inner diameter of 0.25 m and a height of 4 m. A pulverised wood flame is established using an axial burner that is installed on the top of the furnace. Experimental study on a selected pulverised wood with determined size distribution and anisotropy character has been carried out in this furnace. During the experiment, the wall temperatures of the furnace were continuously measured using 8 thermocouples of type K that are installed on the wall with a spacing about 0.5 m. The gas temperatures in the furnace were monitored using 5 fixed suction pyrometers that are placed along the centre of the furnace. At the bottom of the furnace, a fixed gas-sampling probe was installed. The flue gas concentrations were continuously monitored with on-line gas analysers. The extent of combustion was measured through the analysis of sampled gaseous products and condensable solid products. A movable liquid quench probe was used to carry out the gas and solid sampling through a number of sampling holes that are opened along the furnace wall. The quench liquor used is an alkaline water solution containing a small amount of a detergent to dissolve HCN and tar. The quench liquor and solid samples were separated and collected in a knockout pot. The gas was filtered and passed through two bubblers with acidic solution to collect NH{sub 3}. The gas concentrations were then analysed with on-line gas

  9. An experimental study on the characteristics of electromagnetic filter

    International Nuclear Information System (INIS)

    Lee, Geum Yong; Lim, Seung Cheol; Lee, Kun Jai

    1993-01-01

    The electromagnetic filter has been recognized as a technological replacement for the conventional filtration systems of the nuclear power plant coolant. But, as of now there are neither clear understandings of the phenomena occurring in the electromagnetic filter nor the general theoretical analyses. These facts make the application of the electromagnetic filter to the real systems a little risky, and therfore it has not been commercialized although it shows excellent performances in such situations as the plant abnormality, where the conventional filters usually fail. This experimental study of the low power electromagnetic filter aims at the clarification of the general characteristics under varying operational parameters. Since the detailed characteristics may differ from one electromagnetic filter to another, they are considered secondary. The impurities applied are the highly magnetic magnetite (Fe 3 O 4 ) and the diamagnetic cuprous oxide (Cu 2 O). The empirical equations are derived from the experimental data by the regressional analyses. They are classified of three types : Efficiencies vs. Time, Efficiencies vs. Load, and Load vs. Time. The characteristics of the electromagnetic filter observed in this experiment agreed well with other related works in many aspects. Especially in this study, some assumptions and discussions including the physical deposition are combined for the explanations of the filter characteristics found in our and other experimental works. (Author)

  10. Self-Radiolysis of Tritiated Water: Experimental Study and Simulation

    International Nuclear Information System (INIS)

    Heinze, Sylver; Stolz, Thibaut; Ducret, Didier; Colson, Jean-Claude

    2005-01-01

    Radioactive decay of tritium contained in tritiated water leads to the production of gaseous helium and, through self-radiolysis, to the formation of molecular hydrogen and oxygen. For safety management of tritiated water storage, it is essential to be able to predict pressure increase resulting from this phenomenon. The present study aims to identify the mechanisms that take place in self-radiolysis of chemically pure liquid tritiated water. The evolution of the concentration of hydrogen and oxygen in the gas phase of closed vessels containing tritiated water has been followed experimentally. Simulation of pure water radiolysis has been carried out using data from the literature. In order to fit experimental results, simulation should take into account gas phase recombination reaction between hydrogen and oxygen. A simplified system has been extracted from the complete chemical system used to simulate radiolysis. This system allows identifying the basic mechanisms that are responsible for tritiated water self-radiolysis

  11. Electrochemistry of chlorogenic acid: experimental and theoretical studies

    Energy Technology Data Exchange (ETDEWEB)

    Namazian, Mansoor [Department of Chemistry, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of)]. E-mail: namazian@yazduni.ac.ir; Zare, Hamid R. [Department of Chemistry, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of)

    2005-08-10

    Cyclic voltammetry, chronoamperometry and rotating disk electrode voltammetry as well as quantum chemical methods, are used for electrochemical study of chlorogenic acid, as an important biological molecule. The standard formal potential, diffusion coefficient, and heterogeneous electron transfer rate constant of chlorogenic acid in aqueous solution are investigated. Acidic dissociation constant of chlorogenic acid is also obtained. Quantum mechanical calculations on oxidation of chlorogenic acid in aqueous solution, using density functional theory are presented. The change of Gibbs free energy and entropy of oxidation of chlorogenic acid are calculated using thermochemistry calculations. The calculations in aqueous solution are carried out with the use of polarizable continuum solvation method. Theoretical standard electrode potential of chlorogenic acid is achieved to be 0.580 V versus standard calomel electrode (SCE) which is in agreement with the experimental value of 0.617 V obtained experimentally in this work. The difference is consistent with the values we previously reported for other quinone derivatives.

  12. Experimental study on reflooding in advanced tight lattice PWR

    International Nuclear Information System (INIS)

    Hori, K.; Kodama, J.; Teramae, T.

    2000-01-01

    This paper is related to the experimental study on the feasibility of core cooling by re-flooding in a large break loss of coolant accident (LOCA) for the advanced tight lattice pressurized water reactor (PWR). The tight lattice core design should be adopted to improve the conversion ratio. Major one of the key questions of such tight lattice core is the cooling capability under the re-flood condition in a large break LOCA. Forced feed bottom re-flooding experiments have been performed by use of a 4x4 triangular array rod bundle. The rod gap is 0.5 mm, 1.0 mm, or 1.5 mm. The measured peak temperature is below around 1273 K even in case of 1.0/0.5 mm rod gap. And, the evaluation based on the experimental results of rod temperatures and core pressure drop also shows that the core cooling under re-flooding condition is feasible. (author)

  13. An experimental study about efficacy of the drain catheters

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Bum Gyu; Nho, Joon Young; Woo, Hyo Cheol; Hwang, Woo Cheol; Park, Choong Ki; Yoon, Jong Sup [Hallym University College of Medicine, Seoul (Korea, Republic of)

    1993-09-15

    Although percutaneous abscess drainage has become and accepted alternative from of therapy for selected patients with abscess, it is well known that there are several factors in the failure of adequate drainage such as pre- and post-procedural management, technique itself, various features of abscess, and selection and application of catheters. Among these factors, we made an experiment about drainage efficacy of commonly used various catheters with different viscosities of water-glycerin solution under the two different pressure gradients. The experimental values of flow rate were very lower than the calculated values. An efficacy of experimental value was 4-14%. Because the inner diameter of fittings and stopcocks was usually smaller than the inner diameter of catheters, these factors also affected the drain efficacy. Finally, we thought that it will be very helpful to the treatment of patient as well as to study about the catheter drainage, if the drain efficacy of individual catheters has been notified.

  14. Experimental study of hydronic panels system and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Nestor Fonseca [University of Liege Belgium, Thermodynamics Laboratory, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia)

    2011-01-15

    An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure. (author)

  15. Experimental study of hydronic panels system and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca Diaz, Nestor, E-mail: nestorfonseca5@hotmail.co [University of Liege Belgium, Thermodynamics Laboratory, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia)

    2011-01-15

    An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure.

  16. An experimental study on anti-electrostatic gauge rulers

    International Nuclear Information System (INIS)

    Lou, Renjie; Dai, Liping; Sun, Hong

    2013-01-01

    The process of oil filling will produce electrostatic phenomena which may cause fire accidents. There were no reports about research on the danger of static electricity generation in the process of gauging operation to date. This paper presents an experiment on charge transferring quantity of gauge rulers, and calculates the charge transferring quantity of an anti-electrostatic gauge ruler and a metal one, respectively. The results indicate that the charge transferring quantity can be more than 0.1 μC for a metal gauge ruler, while it is less than 0.1 μC for an antistatic gauge ruler. Therefore, this experimental research proves that using an anti-electrostatic gauge ruler is safer than using a metal one. This study also provides some theoretical and experimental evidence for making anti-electrostatic gauge rulers.

  17. Experimental Studies on Combustion Characteristics of Mixed Municipal Solid Waste

    Institute of Scientific and Technical Information of China (English)

    Fan Jiang; Zhonggang Pan; Shi Liu; Haigang Wang

    2003-01-01

    In our country, municipal solid wastes (MSW) are always burnt in their original forms and only a few pretreatments are taken. Therefore it is vital to study the combustion characteristics of mixed waste. In this paper,thermogravimetric analysis and a lab scale fluidized bed facility were used as experimental means. The data in two different experimental systems were introduced and compared. It took MSW 3~3.5 rain to burn out in FB, but in thermogravimetric analyzer, the time is 20~25 min. It can be concluded that, in general, the behavior of a mixture of waste in TGA can be expressed by simple combination of individual components of the waste mixtures.Only minor deviations from the rule were observed. Yet, in Fluidized Bed, it was found that, for some mixtures,there was interference among the components during fluidized bed combustion.

  18. Experimental animal studies of radon and cigarette smoke

    International Nuclear Information System (INIS)

    Cross, F.T.; Dagle, G.E.; Gies, R.A.; Smith, L.G.; Buschbom, R.L.

    1992-01-01

    Cigarette-smoking is a dominant cause of lung cancer and confounds risk assessment of exposure to radon decay products. Evidence in humans on the interaction between cigarette-smoking and exposure to radon decay products, although limited, indicates a possible synergy. Experimental animal data, in addition to showing synergy, also show a decrease or no change in risk with added cigarette-smoke exposures. This article reviews previous animal data developed at Compagnie Generale des Matieres Nucleaires and Pacific Northwest Laboratory (PNL) on mixed exposures to radon and cigarette smoke, and highlights new initiation-promotion-initiation (IPI) studies at PNL that were designed within the framework of a two-mutation carcinogenesis model. Also presented are the PNL exposure system, experimental protocols, dosimetry, and biological data observed to date in IPI animals

  19. Theoretical and experimental study of a thruster discharging a weight

    Science.gov (United States)

    Michaels, Dan; Gany, Alon

    2014-06-01

    An innovative concept for a rocket type thruster that can be beneficial for spacecraft trajectory corrections and station keeping was investigated both experimentally and theoretically. It may also be useful for divert and attitude control systems (DACS). The thruster is based on a combustion chamber discharging a weight through an exhaust tube. Calculations with granular double-base propellant and a solid ejected weight reveal that a specific impulse based on the propellant mass of well above 400 s can be obtained. An experimental thruster was built in order to demonstrate the new idea and validate the model. The thruster impulse was measured both directly with a load cell and indirectly by using a pressure transducer and high speed photography of the weight as it exits the tube, with both ways producing very similar total impulse measurement. The good correspondence between the computations and the measured data validates the model as a useful tool for studying and designing such a thruster.

  20. Design and Experimental Study on Spinning Solid Rocket Motor

    Science.gov (United States)

    Xue, Heng; Jiang, Chunlan; Wang, Zaicheng

    The study on spinning solid rocket motor (SRM) which used as power plant of twice throwing structure of aerial submunition was introduced. This kind of SRM which with the structure of tangential multi-nozzle consists of a combustion chamber, propellant charge, 4 tangential nozzles, ignition device, etc. Grain design, structure design and prediction of interior ballistic performance were described, and problem which need mainly considered in design were analyzed comprehensively. Finally, in order to research working performance of the SRM, measure pressure-time curve and its speed, static test and dynamic test were conducted respectively. And then calculated values and experimental data were compared and analyzed. The results indicate that the designed motor operates normally, and the stable performance of interior ballistic meet demands. And experimental results have the guidance meaning for the pre-research design of SRM.

  1. Experimental study on external condensation heat transfer characteristics of bellows

    International Nuclear Information System (INIS)

    Feng Dianyi; Hu Jiansheng

    2008-01-01

    Flow model and heat transfer of condensation flow outside of bellows have been theoretically and experimentally studied. The formula for calculation of condensation heat transfer coefficient was deduced, and corrected through experiment. The calculation results are accordant with the experimental ones, and the errors is less than 10%. The effect of bellows structure parameters and pipe diameter on the enhancement heat transfer has been investigated. It is found that in the steady flow region, the average condensation heat transfer coefficient in a bellows is 3 ∼ 5 times than that in a straight tube under the same conditions, and when considering the increasing in heat transfer area, the effectiveness of enhancement heat transfer is 5 ∼ 7 times than that in a straight tube. To facilitate the engineering design and application of bellows, the formula for the calculation of the average heat transfer coefficient of a fluid in a bellows was also given. (authors)

  2. An Experimental Study for Radiation Nephritis in Rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myung Jae [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1972-09-15

    Experimental radiation nephritis was produced in 15 rabbits by X-irradiation. About 2, 000gamma(tissue doses) were given to both kidneys of a rabbit in 5 days. Other tissues and organs except both kidneys were protected with 2 mm thickened lead plates. 5 weeks after the last irradiation, blood pictures, blood pressures, B.U.N., serum creatinine, Ca, Mg, Fe levels and serum erythropoietin activity of the irradiated rabbits were studied. After finishing above studies, rabbits were sacrificed and both kidneys were removed and examined histopathologically. Same laboratory and pathological studies were performed in 6 control rabbits. In this study, the author obtained following results. 1) Both kidneys of rabbits with experimental radiation nephritis showed marked histopathological changes, i.e.: renal tubules showed diffuse cloudy swelling, impacted intraluminal hyaline casts and focal precipitations of lime salts on the tubular epithelium. Diffuse interstitial fatty necrosis and various degrees of fibrotic infiltrations on the interstitium were also seen in association with focal lymphocytic infiltrations. Hyaline degenerations were observed on the glomeruli and small vessels. 2) Experimental radiation nephritis rabbits showed marked lowering in R.B.C. counts, decreased hemoglobin levels, low hematocrit values and leucopenia in comparison with those of control rabbits. (P<0.01). (Table 1 and 2). 3) Mild proteinuria were observed in experimental radiation nephritis in rabbits. 4) The levels of B.U.N. and serum creatinine increased in experimental radiation nephritis. (P<0.01). (Table 1, 3 and 4). 5) The levels of serum Ca and Mg Showed no statistical difference in comparison with those of control rabbits. (P>0.05). (Table 3 and 4). 6) No statistical correlations were observable between the levels of B.U.N. and Hb. values. (gamma=-0. 223). No close correlations (gamma=-0.338) were noticed between the levels of B.U.N. and serum iron levels. 7) Erythropoietin activity (R

  3. Experimental and numerical study of a printed circuit heat exchanger

    International Nuclear Information System (INIS)

    Chen, Minghui; Sun, Xiaodong; Christensen, Richard N.; Shi, Shanbin; Skavdahl, Isaac; Utgikar, Vivek; Sabharwall, Piyush

    2016-01-01

    temperature increase and the other for helium inlet temperature decrease, were experimentally carried out to assess the applicability of the dynamic model. Comparisons of the numerical results with the experimental data show that the dynamic model is successful in predicting the experimental transient scenarios. Although difference was observed between the numerical results and experimental data, the comparisons suggest that the numerical solutions are sufficiently accurate and conservative and that the applicability of the dynamic model proposed for predicting the steady-state and transient performance of the straight-channel PCHE has been confirmed. Furthermore, both the numerical and experimental studies provide insights into the dynamic performance of the PCHE.

  4. Experimental Study on the WavePiston Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Angelelli, E.

    This report presents the results of an experimental study of the power performance of the WavePiston wave energy converter. It focuses mainly on evaluating the power generating capabilities of the device and the effect of the following issues: Scaling ratios PTO loading Wave height and wave period...... dependency Oblique incoming waves Distance between plates During the study, the model supplied by the client, WavePiston, has been rigorously tested as all the anticipated tests have been done thoroughly and during all tests, good quality data has been obtained from all the sensors....

  5. Pulsed total dose damage effect experimental study on EPROM

    International Nuclear Information System (INIS)

    Luo Yinhong; Yao Zhibin; Zhang Fengqi; Guo Hongxia; Zhang Keying; Wang Yuanming; He Baoping

    2011-01-01

    Nowadays, memory radiation effect study mainly focus on functionality measurement. Measurable parameters is few in china. According to the present situation, threshold voltage testing method was presented on floating gate EPROM memory. Experimental study of pulsed total dose effect on EPROM threshold voltage was carried out. Damage mechanism was analysed The experiment results showed that memory cell threshold voltage negative shift was caused by pulsed total dose, memory cell threshold voltage shift is basically coincident under steady bias supply and no bias supply. (authors)

  6. Game theory and experimental games the study of strategic interaction

    CERN Document Server

    Colman, Andrew M

    1982-01-01

    Game Theory and Experimental Games: The Study of Strategic Interaction is a critical survey of the essential ideas of game theory and the findings of empirical research on strategic interaction. Some experiments using lifelike simulations of familiar kinds of strategic interactions are presented, and applications of game theory to the study of voting, the theory of evolution, and moral philosophy are discussed.Comprised of 13 chapters, this volume begins with an informal definition of game theory and an outline of the types of social situations to which it applies. Games of skill, games of cha

  7. Experimental study and optimization of a solar still

    Energy Technology Data Exchange (ETDEWEB)

    Menguy, G; Chassagne, G; Sfeir, A; Saab, J

    1976-01-01

    The aim of this investigation was to study the influence of different parameters on the operation of a solar still for production of distilled water. These parameters are essentially classified in two categories: external parameters such as solar radiation, ambient temperatures and wind speed; internal parameters such as thermal insulation, water film thickness and the color of the side walls. The experiments were carried out on two identical stills. The effects of the different parameters were investigated by comparing the output of the two stills under different experimental conditions. This study resulted in the development of a simple inexpensive still which can readily be put in practical use in the area.

  8. [Experimental study on spectra of compressed air microwave plasma].

    Science.gov (United States)

    Liu, Yong-Xi; Zhang, Gui-Xin; Wang, Qiang; Hou, Ling-Yun

    2013-03-01

    Using a microwave plasma generator, compressed air microwave plasma was excited under 1 - 5 atm pressures. Under different pressures and different incident microwave power, the emission spectra of compressed air microwave plasma were studied with a spectra measuring system. The results show that continuum is significant at atmospheric pressure and the characteristic will be weakened as the pressure increases. The band spectra intensity will be reduced with the falling of the incident microwave power and the band spectra were still significant. The experimental results are valuable to studying the characteristics of compressed air microwave plasma and the generating conditions of NO active groups.

  9. An experimental study of client-side Spotify peering behaviour

    OpenAIRE

    Ellis, M.; Strowes, S.; Perkins, C.

    2011-01-01

    Spotify is a popular music-streaming service which has seen widespread use across Europe. While Spotify’s server-side behaviour has previously been studied, little is known about the client-side behaviour. In this paper, we describe an experimental study where we collect packet headers for Spotify traffic over multiple 24-hour time frames at a client host. Two distinct types of behaviour are observed, when tracks are being downloaded, and when the client is only serving requests from other pe...

  10. Experimental study on concrete cutting by CO2 laser beam

    International Nuclear Information System (INIS)

    Kutsumizu, Akira; Tomura, Hidemasa; Wakizaka, Tatsuya; Hishikawa, Kyoichi; Moriya, Masahiro

    1994-01-01

    Methods for dismantling nuclear reactor facilities must meet particularly exacting requirements imposed by heavily reinforced and radioactivated reactor shield walls. Conventional methods do not meet all such requirements, however. Intrigued by excellent characteristics of the laser cutting method relative to nuclear facility demolition, we carried out an experimental study to make a comprehensive evaluation of its characteristics, especially for deep cutting, with success in identifying main factors affecting the cutting depth of a laser and characterizing its cutting behavior. The study results indicate that a 50 kW class CO 2 laser has a potential to provide a practicable cutting speed and depth. (author)

  11. Experimental studies of the laser-controlled collective ion accelerator

    International Nuclear Information System (INIS)

    Destler, W.W.; Rodgers, J.; Segalov, Z.

    1989-01-01

    Detailed experimental studies of a collective acceleration experiment in which a time-sequenced laser-generated ionization channel is used to control the propagation of an intense relativistic electron beamfront are presented. Ions trapped in the potential well at the beamfront are accelerated as the velocity of the beamfront is increased in a manner controlled by the time-dependent axial extent of the ionization channel. Beamfront propagation data for two different accelerating gradients are presented, together with results of ion acceleration studies for both gradients

  12. Theoretical and experimental study of mixed solvent electrolytes

    International Nuclear Information System (INIS)

    Cummings, P.T.; O'Connell, J.P.

    1990-01-01

    In the original proposal to study mixed solvent electrolyte solutions, four major goals were formulated: fundamental modeling of mixed solvent electrolytes using numerically solved integral equation approximation theories; evaluation of intermolecular pair potential models by computer simulation of selected systems for comparison with experiment and the numerical integral equation studies; development of fundamentally based correlations for the thermodynamic properties of mixed solvent electrolyte solutions using analytically solvable statistical mechanical models; and extension of experimental database on mixed solvent electrolytes by performing vapor-liquid equilibrium measurements on selected systems. This paper discusses the progress on these goals

  13. Manipulation of pain catastrophizing: An experimental study of healthy participants

    Directory of Open Access Journals (Sweden)

    Joel E Bialosky

    2008-11-01

    Full Text Available Joel E Bialosky1*, Adam T Hirsh2,3, Michael E Robinson2,3, Steven Z George1,3*1Department of Physical Therapy; 2Department of Clinical and Health Psychology; 3Center for Pain Research and Behavioral Health, University of Florida, Gainesville, Florida, USAAbstract: Pain catastrophizing is associated with the pain experience; however, causation has not been established. Studies which specifically manipulate catastrophizing are necessary to establish causation. The present study enrolled 100 healthy individuals. Participants were randomly assigned to repeat a positive, neutral, or one of three catastrophizing statements during a cold pressor task (CPT. Outcome measures of pain tolerance and pain intensity were recorded. No change was noted in catastrophizing immediately following the CPT (F(1,84 = 0.10, p = 0.75, partial η2 < 0.01 independent of group assignment (F(4,84 = 0.78, p = 0.54, partial η2 = 0.04. Pain tolerance (F(4 = 0.67, p = 0.62, partial η2 = 0.03 and pain intensity (F(4 = 0.73, p = 0.58, partial η2 = 0.03 did not differ by group. This study suggests catastrophizing may be difficult to manipulate through experimental pain procedures and repetition of specific catastrophizing statements was not sufficient to change levels of catastrophizing. Additionally, pain tolerance and pain intensity did not differ by group assignment. This study has implications for future studies attempting to experimentally manipulate pain catastrophizing.Keywords: pain, catastrophizing, experimental, cold pressor task, pain catastrophizing scale

  14. Experimental Study of Axially Tension Cold Formed Steel Channel Members

    Science.gov (United States)

    Apriani, Widya; Lubis, Fadrizal; Angraini, Muthia

    2017-12-01

    Experimental testing is commonly used as one of the steps to determine the cause of the collapse of a building structure. The collapse of structures can be due to low quality materials. Although material samples have passed laboratory tests and the existing technical specifications have been met but there may be undetected defects and known material after failure. In this paper will be presented Experimental Testing of Axially Tension Cold Formed Steel Channel Members to determine the cause of the collapse of a building roof truss x in Pekanbaru. Test of tensile strength material cold formed channel sections was performed to obtain the main characteristics of Cold Formed steel material, namely ultimate tensile strength loads that can be held by members and the yield stress possessed by channel sections used in construction. Analysis of axially tension cold formed steel channel section presents in this paper was conducted through experimental study based on specificationsAnnualBook of ASTM Standards: Metal Test methods and Analitical Procedures, Section 3 (1991). The result of capacity loads experimental test was compared with design based on SNI 03-7971-2013standard of Indonesia for the design of cold formed steel structural members. The results of the yield stress of the material will be seen against the minimum allowable allowable stress range. After the test, the percentace of ultimate axial tension capacity theory has a result that is 16.46% larger than the ultimate axial tension capacity experimental. When compared with the load that must be borne 5.673 kN/m it can be concluded that 2 specimens do not meet. Yield stress of member has fulfilled requirement that wass bigger than 550 MPa. Based on the curve obtained ultimate axial tension capacity theory, results greater than experimental. The greatest voltage value (fu) is achieved under the same conditions as its yield stress. For this specimen with a melting voltage value fy = 571.5068 MPa has fulfilled the

  15. Experimental studies of renal blood flow by digitized functional angiography

    International Nuclear Information System (INIS)

    Buersch, J.H.; Ochs, C.; Hahne, H.J.; Heintzen, P.H.

    1985-01-01

    New techniques of digital image processing have been experimentally tested for the assessment of renal blood flow. The underlying principle in functional angiography is the extraction of flow parameters. Basically, density-time variations of the contrast medium are analayzed from to each picture element of a 256x256 matrix. The real-time acquisition rate of images was 25/sec. For the calculation of angiographic flow a PDP 11/40 computer was used to interactively perform a time dependent segmentation of the renal arteries and the aorta. Subsequently, volume flow was calculated in relative units for the specific vascular segments under study. 15 control angiograms were made in 5 animals with cardiac output ranging between 0.8 to 2.2l/min. Unilateral renal blood flow was calculated as 24+-3.4% of pre-renal aortic flow without systematic side differences. Reproducibility from repeated flow measurements showed an SD of +-1.8% of the individual pre-renal aortic flow. Renal flow was also measured in 3 animals with an experimentally created 50% flow reduction of the left kidney. Angiographic flow in the left renal artery dropped to 12+-2% of pre-renal flow. The present experimental data suggest that digital angiography has sufficient diagnostic capabilities for the detection of abnormal renal blood flow. The technique may serve as a useful diagnostic adjunct to conventional angiography and has the potential of assisting in the evaluation of renal vascular hypertension. (orig.) [de

  16. Nonlocal Regularized Algebraic Reconstruction Techniques for MRI: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Xin Li

    2013-01-01

    Full Text Available We attempt to revitalize researchers' interest in algebraic reconstruction techniques (ART by expanding their capabilities and demonstrating their potential in speeding up the process of MRI acquisition. Using a continuous-to-discrete model, we experimentally study the application of ART into MRI reconstruction which unifies previous nonuniform-fast-Fourier-transform- (NUFFT- based and gridding-based approaches. Under the framework of ART, we advocate the use of nonlocal regularization techniques which are leveraged from our previous research on modeling photographic images. It is experimentally shown that nonlocal regularization ART (NR-ART can often outperform their local counterparts in terms of both subjective and objective qualities of reconstructed images. On one real-world k-space data set, we find that nonlocal regularization can achieve satisfactory reconstruction from as few as one-third of samples. We also address an issue related to image reconstruction from real-world k-space data but overlooked in the open literature: the consistency of reconstructed images across different resolutions. A resolution-consistent extension of NR-ART is developed and shown to effectively suppress the artifacts arising from frequency extrapolation. Both source codes and experimental results of this work are made fully reproducible.

  17. Experimental study of self-leveling behavior in debris bed

    International Nuclear Information System (INIS)

    Zhang, Bin; Harada, Tetsushi; Hirahara, Daisuke; Matsumoto, Tatsuya; Morita, Koji; Fukuda, Kenji; Yamano, Hidemasa; Suzuki, Tohru; Tobita, Yoshiharu

    2008-01-01

    After a core disruptive accident in a sodium-cooled fast reactor, core debris may settle on locations such as within the core-support structure or in the lower inlet plenum of the reactor vessel as debris beds, as a consequence of rapid quenching and fragmentation of core materials in subcooled sodium. The particle beds that are initially of varying depth have been observed to undergo a process of self-leveling when sodium boiling occurs within the beds. The boiling is believed to provide the driven force with debris needed to overcome resisting forces. Self-leveling ability has much effect on heat-removal capability of debris beds. In the present study, characteristics of self-leveling behaviors were investigated experimentally with simulant materials. Although the decay heat from fuel debris drives the coolant boiling in reactor accident conditions, the present experiments employed depressurization boiling of water to simulate axially increasing void distribution in a debris bed, which consists of solid particles of alumina or lead with different density. The particle size (from 0.5 mm to 6 mm in diameter) and shape (spherical or non-spherical particles) were also taken as experimental parameters. A rough criteria for self-leveling occurrence is proposed and compared with the experimental results. Characteristics of the self-leveling behaviors observed are analyzed and extrapolate to reactor accident conditions. (author)

  18. Experimental Method For Studying Habitual Behavior In Food Consumption

    Directory of Open Access Journals (Sweden)

    Naziha Kasraoui

    2015-03-01

    Full Text Available Abstract To investigate the process of habit formation in everyday life a sample of 126 participants students chooses an eating and drinking for three periods weeks. They completed the self-report habit each period and we have recorded their choices. All participants provided sufficient data for analysis and collected experimental data were examined over the study periods 3 weeks. Experimental analysis was used to examine the persistence of habit formation process in the behavior of participants. The game is carried out with 126 students and repeated for three periods. Using experimental laboratory data approach and economic analysis elasticity results show that into the presence of labor income and for 126 students of whom approximately 70 showed that habit formation process is persist in their behaviors along the three periods. The rest 30 of them who dont present habit formation in their behavior for the three periods did not materially affect our conclusion about the assumption of habit formation process. Participants to the game persistently spend too much in early periods they learn rapidly from their own experience to consume the same choice of meals and drinks. Their spending is closely linked to optimal consumption non conditional on earlier spending and they choose the same basket of goods in the future horizon which shows that theres a habit formation in the behaviors of participants.

  19. Stability of nanofluids: Molecular dynamic approach and experimental study

    International Nuclear Information System (INIS)

    Farzaneh, H.; Behzadmehr, A.; Yaghoubi, M.; Samimi, A.; Sarvari, S.M.H.

    2016-01-01

    Highlights: • Nanofluid stability is investigated and discussed. • A molecular dynamic approach, considering different forces on the nanoparticles, is adopted. • Stability diagrams are presented for different thermo-fluid conditions. • An experimental investigation is carried out to confirm the theoretical approach. - Abstract: Nanofluids as volumetric absorbent in solar energy conversion devices or as working fluid in different heat exchangers have been proposed by various researchers. However, dispersion stability of nanofluids is an important issue that must be well addressed before any industrial applications. Conditions such as severe temperature gradient, high temperature of heat transfer fluid, nanoparticle mean diameters and types of nanoparticles and base fluid are among the most effective parameters on the stability of nanofluid. A molecular dynamic approach, considering kinetic energy of nanoparticles and DLVO potential energy between nanoparticles, is adopted to study the nanofluid stability for different nanofluids at different working conditions. Different forces such as Brownian, thermophoresis, drag and DLVO are considered to introduce the stability diagrams. The latter presents the conditions for which a nanofluid can be stable. In addition an experimental investigation is carried out to find a stable nanofluid and to show the validity of the theoretical approach. There is a good agreement between the experimental and theoretical results that confirms the validity of our theoretical approach.

  20. Experimental and theoretical study of Co sorption in clay montmorillonites

    Science.gov (United States)

    Gil Rebaza, A. V.; Montes, M. L.; Taylor, M. A.; Errico, L. A.; Alonso, R. E.

    2018-03-01

    Montmorillonite (MMT) clays are 2:1 layered structures which in natural state may allocate different hydrated cations such as M-nH2O (M = Na, Ca, Fe, etc) in its interlayer space. Depending on the capability for ion sorption, these materials are interesting for environmental remediation. In this work we experimentally study the Co sorption in a natural Na-MMT using UV-visible spectrometry and XRD on semi-oriented samples, and then analyze the sorption ability of this clay by means of ab initio calculation performed on pristine MMT. The structural properties of Na-MMT and Co-adsorbed MMT, and the hyperfine parameters at different atomic sites were analyzed and compared with the experimental ones for the first, and for the case of the hyperfine parameters, presented for the first time for the last. The theoretical predictions based on total energy considerations confirm that Co incorporation replacing Na is energetically favorable. Also, the basal spacing d001 experimentally obtained is well reproduced.

  1. Experimental study of the process of cutting of sugarcane bagasse

    International Nuclear Information System (INIS)

    Arzolaa, Nelson; Garcia, Joyner

    2015-01-01

    Biomass densification has encouraged significant interest around the world as a technique for utilization of agro and forest residues as an energy source, and pellets/briquettes production has grown rapidly in last few years. The cutting process is one of the most important steps for biomass preparation prior densification. This stage helps to homogenize the raw material and therefore facilitate handling, feeding and filling in the briquetting equipment. The aim of this work was to study the behavior of sugarcane bagasse submitted to cutting, as a function of its moisture content, angle of the blade edge and cutting speed. The specific cutting energy and peak cutting force were measure using an experimental facility developed for this series of experiments. An analysis of the results of the full factorial experimental design using a statistical analysis of variance (ANOVA) was performed. The response surfaces and empirical models for the specific cutting energy and peak cutting force were obtained using statistical analysis system software. Low angle of the blade edge and low moisture content are, in this order, the most important experimental factors in determining a low specific cutting energy and a low peak cutting force respectively. The best cutting conditions are achieved for an angle of blade edge of 20.8° and a moisture content of 10% w. b. The results of this work could contribute to the optimal design of sugarcane bagasse pre-treatment systems. (full text)

  2. The Experimental Study Of Effects Of Irradiation On Osseointegration

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kwan Soo; Lee, Sang Rae; Hwang, Eui Hwan [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Kyunghee University, Seoul (Korea, Republic of)

    1999-02-15

    The purpose of this study was to investigate the effects of the Co-60 gamma irradiation on the osseointegration. 2.0 mm titanium alloy screw implants were placed in the tibial metaphysics of the rabbits, bilaterally. The mean length of the implants was 6.0 mm. The right tibia was irradiated with a single dose of 15 Gy from 6{sup 0C}o teletherapic machine at 5th postoperative day. The experimental group was irradiated tibia. The control group was non-irradiated tibia. To observe the phase of bone formation, the bone labeling by intramuscular injection of 20 mg/Kg of Tetracycline, Calcein, Alizarin red S, was performed. The rabbits were sacrificed on the 1st, 2nd, 4th, 6th, 8th week and the tibia including implants were taken, and then the specimens were examined by the microradiography, light microscopy, and fluorescent microscopy.The obtained results were as follows; 1. There were connective tissue between bone and titanium at 1st week, in both group. Especially, the many empty lacunae without nucleus and obscure cytoplasm in experimental group, were observed. 2. The osteons were observed at 4th week in control group, and at 6th week in experimental group. The bone formation in experimental group was retarded as compared to the control group. 3. In fluorescent microscopy, bone labelling band was observed as linear, arc or concentric shape. Occasionary interrupted labelling band was observed, which is demonstrated bone remodeling. 4. In microradiographic examination, the radiolucent image was found between bone and implant with widening of bone marrow spaces as compared to the control group.

  3. Experimental fretting-wear studies of steam generator materials

    International Nuclear Information System (INIS)

    Fisher, N.J.; Chow, A.B.; Weckwerth, M.K.

    1994-01-01

    Flow-induced vibration of steam generator tubes results in fretting-wear damage due to impacting and rubbing of the tubes against their supports. This damage can be predicted by computing tube response to flow-induced excitation forces using analytical techniques, and then relating this response to resultant wear damage using experimentally-derived wear coefficients. Fretting-wear of steam generator materials has been studied experimentally at Chalk River Laboratories for two decades. Tests are conducted in machines that simulate steam generator environmental conditions and tube-to-support dynamic interactions. Different tube and support materials, tube-to-support clearances and tube support geometries have been studied. As well, the effect of environmental conditions, such as temperature, oxygen content, pH and chemistry control additive, have been investigated. Early studies showed that damage was related to contact force as long as other parameters, such as geometry and motion were held constant. Later studies have shown that damage is related to a parameter called work-rate, which combines both contact force and sliding distance. Results of short- and long-term fretting-wear tests for CANDU steam generator materials at realistic environmental conditions are presented. These results demonstrate that work-rate is appropriate correlating parameter for impact-sliding interaction

  4. Experimental studies of pion-nucleus interactions at intermediate energies

    International Nuclear Information System (INIS)

    1991-01-01

    This report summarizes the work on experimental research in intermediate energy nuclear physics carried out at New Mexico State University in 1991 under a great from the US Department of Energy. Most of these studies have involved investigations of various pion-nucleus interactions. The work has been carried out both with the LAMPF accelerator at the Los Alamos National Laboratory and with the cyclotron at the Paul Scherrer Institute (PSI) near Zurich, Switzerland. Part of the experimental work involves measurements of new data on double-charge-exchange scattering, using facilities at LAMPF which we helped modify, and on pion absorption, using a new detector system at PSI that covers nearly the full solid-angle region which we helped construct. Other work involved preparation for future experiments using polarized nuclear targets and a new high-resolution spectrometer system for detecting π 0 mesons. We also presented several proposals for works to be done in future years, involving studies related to pi-mesonic atoms, fundamental pion-nucleon interactions, studies of the difference between charged and neutral pion interactions with the nucleon, studies of the isospin structure of pion-nucleus interactions, and pion scattering from polarized 3 He targets. This work is aimed at improving our understanding of the pion-nucleon interaction, of the pion-nucleus interaction mechanism, and of nuclear structure

  5. Does Faculty Follow the Recommended Structure for a New Classroom-based, Daily Formal Teaching Session for Anesthesia Residents?

    DEFF Research Database (Denmark)

    Anwar, Anjum; Tanaka, Pedro; Madsen, Matias V

    2016-01-01

    BACKGROUND: A newly implemented 15-minute classroom-based, formal teaching session for anesthesia residents is given three times daily by the same faculty. The faculty member was provided a suggested template for the presentation. The template structure was developed by a group of residents......, and 31% used a clinical case vignette presentation to introduce the keyword. The most common visuals were the use of a picture (38%) and a chart or a graph (35%). We also saw that 65% of the sessions had active involvement of residents. With respect to time and slide limitations mentioned in the template...... of the residency curriculum more than two years after their implementation....

  6. An experimental study on suspended sodium droplet combustion (3)

    International Nuclear Information System (INIS)

    Sato, Kenji

    2005-03-01

    As part of studies for phenomenological investigation of sodium droplet burning behavior, in our previous experimental studies for suspended single sodium droplet, behavior of ignition process and succeeding combustion, ignition delay time, and droplet temperature history had been investigated. In this study, combustion experiments of suspended sodium droplet were performed in upward dry air flow by expanding the range of free-stream velocity U of air flow into 400 cm/s with initial droplet temperature Ti=300, 350, and 400degC and initial droplet diameter 4 mm at first. Then, the combustion experiments were also performed by changing the initial droplet diameter from 2.3 to 4.4 mm with Ti=350 and 400degC and U=100 cm/s. From the experimental results, the effects of free-stream velocity, initial droplet temperature, and initial droplet diameter on the ignition/burning behavior and ignition delay time were examined. The obtained results are as follows: (1) Ignition phenomena of suspended droplet were observed for all examined experimental conditions up to 400 cm/s. The orange emission observed at the moment of ignition occurs simultaneously over whole droplet surface except the top region of it. (2) The feature of the dependence of ignition delay time on the free-stream velocity is independent of the initial droplet temperature. With the increase of the free-stream velocity, up to 300 cm/s the ignition delay time decreases with decreasing dependency, and then the dependency increases more. (3) The ignition delay time increases with the increase of initial droplet diameter. The dependency increases as the initial droplet diameter increases. The ignition delay time extrapolated toward zero diameters from the obtained results becomes to be essentially zero. (author)

  7. Experimental study of dynamic stall on Darrieus wind turbine blades

    Science.gov (United States)

    Brochier, G.; Fraunie, P.; Beguier, C.; Paraschivoiu, I.

    1985-12-01

    An experimental study of periodic vortex phenomena was performed on a model of a two straight-bladed Darrieus wind turbine under controlled-rotation conditions in the IMST water tunnel. The main focus of interest was the tip-speed ratios at which dynamic stall appears. Observations of this phenomenon from dye emission and the formation of hydrogen bubbles were made in the form of photographs, film and video recordings. Velocity measurements were obtained using the Laser-Doppler Velocimeter and components of velocity fluctuations could be determined quantitatively.

  8. Experimental study of intensive electron beam scattering in melting channel

    International Nuclear Information System (INIS)

    Balagura, V.S.; Kurilko, V.I.; Safronov, B.G.

    1988-01-01

    Multiple scattering of an intensive electron beam at 28 keV energy passing through a melting channel in iron targets is experimentally studied. The dependence of scattering on the melting current value is established. The material density in the channel on the basis of the binary collision method is evaluated. It is shown that these density values are of three orders less than the estimations made on the basis of the data on energy losses of electrons in the channel. 6 refs.; 4 figs

  9. Experimental study of buoyancy driven natural ventilation through horizontal openings

    OpenAIRE

    Heiselberg, Per; Li, Zhigang

    2007-01-01

    An experimental study of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. Measurements were made for opening ratios L/D range from 0.027 to 4.455, where L and D are the length and the diameter of the opening, respectively. The bidirectional air flow rate was measured using constant injection tracer gas technique. Smoke visualizations showed that the air flow patterns are highly transient, unstable and complex, and ...

  10. Revisiting dibenzothiophene thermochemical data: Experimental and computational studies

    International Nuclear Information System (INIS)

    Freitas, Vera L.S.; Gomes, Jose R.B.; Ribeiro da Silva, Maria D.M.C.

    2009-01-01

    Thermochemical data of dibenzothiophene were studied in the present work by experimental techniques and computational calculations. The standard (p 0 =0.1MPa) molar enthalpy of formation, at T = 298.15 K, in the gaseous phase, was determined from the enthalpy of combustion and sublimation, obtained by rotating bomb calorimetry in oxygen, and by Calvet microcalorimetry, respectively. This value was compared with estimated data from G3(MP2)//B3LYP computations and also with the other results available in the literature.

  11. Generating physical symptoms from visual cues: An experimental study

    OpenAIRE

    Ogden, J; Zoukas, S

    2010-01-01

    This experimental study explored whether the physical symptoms of cold, pain and itchiness could be generated by visual cues, whether they varied in the ease with which they could be generated and whether they were related to negative affect. Participants were randomly allocated by group to watch one of three videos relating to cold (e.g. ice, snow, wind), pain (e.g. sporting injuries, tattoos) or itchiness (e.g. head lice, scratching). They then rated their self-reported symptoms of cold, pa...

  12. Experimental power reactor dc generator energy storage study

    International Nuclear Information System (INIS)

    Heck, F.M.; Smeltzer, G.S.; Myers, E.H.; Kilgore, L.

    1978-01-01

    This study covers the use of dc generators for meeting the Experimental Power Reactor Ohmic Heating Energy Storage Requirements. The dc generators satisfy these requirements which are the same as defined in WFPS-TME-038 which covered the use of ac generators and homopolar generators. The costs of the latter two systems have been revised to eliminate first-of-a-kind factors. The cost figures for dc generators indicate a need to develop larger machines in order to take advantage of the economy-of-scale that the large ac machines have. Each of the systems has its own favorable salient features on which to base a system selection

  13. An experimental study of steam explosions involving chemically reactive metal

    International Nuclear Information System (INIS)

    Cho, D.H.; Armstrong, D.R.; Gunther, W.H.; Basu, S.

    1997-01-01

    An experimental study of molten zirconium-water explosions was conducted. A 1-kg mass of zirconium melt was dropped into a column of water. Explosions took place only when an external trigger was used. In the triggered tests, the extent of oxidation of the zirconium melt was very extensive. However, the explosion energetics estimated were found to be very small compared to the potential chemical energy available from the oxidation reaction. Zirconium is of particular interest, since it is a component of the core materials of the current nuclear power reactors. This paper describes the test apparatus and summarizes the results of four tests conducted using pure zirconium melt

  14. Experimental study of steam condensation regime map for simplified spargers

    International Nuclear Information System (INIS)

    Kim, Y. S.; Yoon, Y. J.; Song, C. H.; Park, C. K.; Kang, H. S.; Jun, H. K.

    2003-01-01

    An experimental study was conducted to produce a condensation regime map for single-hole and 4-hole steam spargers using GIRLS facility. The regime map for a single-hole sparger was derived using parameters such as the frequency and magnitude of the dynamic pressure. For 4-hole sparager, the regime map was derived using the trends of sound and dynamic pressure. Using the single-hole and 4-hole data, a steam jet condensation regime map was suggested with respect to pool temperature and steam mass flux

  15. Experimental study on a cold neutron source of solid methylbenzene

    Energy Technology Data Exchange (ETDEWEB)

    Utsuro, M; Sugimoto, M; Fujita, Y [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    1975-10-01

    An experimental study to produce cold neutrons with low temperature solid mesitylene as cold moderator in liquid helium and liquid nitrogen cryostats is reported. Measured cold neutron spectra by using an electron linac and time-of-flight method shows that this material is a better cold moderator than light water ice, giving the cold neutron output not so much inferior to that of solid methane in the temperature range above about 20 K and in the neutron energy region above about 1 MeV.

  16. Experimental study of buoyancy driven natural ventilation through horizontal openings

    DEFF Research Database (Denmark)

    Heiselberg, Per; Li, Zhigang

    2007-01-01

    An experimental study of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. Measurements were made for opening ratios L/D range from 0.027 to 4.455, where L and D are the length and the diameter of the opening......, respectively. The bidirectional air flow rate was measured using constant injection tracer gas technique. Smoke visualizations showed that the air flow patterns are highly transient, unstable and complex, and that air flow rates oscillate with time. Correlations between the Froude number Fr and the L/D ratio...

  17. Experimental study of charmed baryons at SuperLEAR

    International Nuclear Information System (INIS)

    Poulet, M.

    1991-01-01

    The possibility to study and detect the charmed baryons at SuperLEAR was examined. It was found that it is possible only if the search is restricted to the single charm baryons Λ c , Σ c , Ξ c . The experimental approach requires high luminosity and some complexity of the detection system. It has to be considered as a second generation jet target experiment in a range of p-bar momentum from 8 to 15 GeV/c. (R.P.) 12 refs., 2 figs

  18. Experimental and numerical study of pleated filters clogging

    International Nuclear Information System (INIS)

    Gervais, Pierre-Colin

    2013-01-01

    Pleated filters are widely used in air treatments because of the advantageous effective surface to overall dimension ratio they offer. Their major drawback though resides in their reduced lifetime which still needs to be controlled. Indeed, when clogging, the pressure drop considerably increases, the filtration flow is then no longer maintained which might lead to the deterioration of the media. It is then crucial to characterize the evolution of the pressure drop under operating conditions in order to best design these equipments. Part of our work consisted in studying how the operating conditions influence the geometry of the deposit. To do so, we used Single- Photon Emission Computed Tomography (SPECT), a non-destructive imaging technique that keeps intact the particle structuring. The visualization of aerosol deposit at the beginning of the filtration process allows observing preferential particle deposition on the whole height of the pleat. A numerical approach was used to study the permeability of bimodal fibrous media and we experimentally studied the local velocity as well as the biphasic flow inside pleated filter media. Comparison between experiments and simulations allowed us to validate the Geodict code for a wide range of media properties and velocities. Regarding bimodal fibrous media, the fast data acquisition has allowed testing several existing models which resulted in classifying them in a unique way. If the experimental results on the initial deposition in pleated filters are encouraging, those related to beforehand clogging point to several improvements regarding the technique we used. (author) [fr

  19. EXPERIMENTAL STUDY OF THE PRODUCTION OF SOLAR HYDROGEN IN ALGERIA

    Directory of Open Access Journals (Sweden)

    W. Bendaikha

    2015-08-01

    Full Text Available Hydrogen is a sustainable fuel option and one of the potential solutions for the current energy and environmental problems. In this study hydrogen is produced using a hydrogen generator with a Proton Exchange Membrane (PEM electrolyser. An experimental study is done in the Center of Development of the Renewable Energy, Algiers, Algeria.The experimental device contains essentially a photovoltaic module, a PEM electrolyser, a gasometer and the devices of measures of characteristics of the PEM electrolyser as well as two pyranometers for the horizontal and diffuse global radiance registration. This system in pilots scale is permitted on the one hand, to measured and analyzed the characteristics: of the PEM electrolyser for two different pressures of working (Patm and P=3 bar, on the other hand, to study the volume of hydrogen produces in the time with different sources of electrical power (generator, photovoltaic module, fluorescent lamp, the efficiency for every case is calculated and compared. We present in this paper the variation of the solar hydrogen flow rate produced according to the global radiance and according to the time for a typical day’s of August.

  20. Experimental study of friction in aluminium bolted joints

    Science.gov (United States)

    Croccolo, D.; de Agostinis, M.; Vincenzi, N.

    2010-06-01

    This study aims at developing an experimental tool useful to define accurately the friction coefficients in bolted joints and, therefore, at relating precisely the tightening torque to the bolt preloading force in some special components used in front motorbike suspensions. The components under investigation are some clamped joints made of aluminium alloy. The preloading force is achieved by applying a torque wrench to the bolt head. Some specific specimens have been appropriately designed and realized in order to study the tribological aspects of the tightening phase. Experimental tests have been performed by applying the Design of Experiment (DOE) method in order to obtain a mathematical model for the friction coefficients. Three replicas of a full factorial DOE at two levels for each variable have been carried out. The levels include cast versus forged aluminium alloy, anodized versus spray-painted surface, lubricated versus unlubricated screw, and first tightening (fresh unspoiled surfaces) versus sixth tightening (spoiled surfaces). The study considers M8x1.25 8.8 galvanized screws.

  1. [An experimental study of the healing of velour grafts].

    Science.gov (United States)

    Kobayashi, O

    1986-02-01

    An experimental study of implantation of velour grafts in the abdominal aorta or the external iliac artery of dogs was conducted with the object of evaluating the type of velour surface best fit for small-caliber artery implantation. Velour grafts measuring 4mm in diameter with differing velour surfaces were used as materials. Velour grafts now available on the market differ not only in velour surface but also in structure, notably in porosity and wall thickness. Hence each of the grafts used was reversed (i.e. inside out) and thus new grafts were prepared. These grafts were considered most suitable for making a comparative study of the effects of velour surface on healing. Macroscopic and histological findings revealed that each graft was good healing with the rate of patency as high as 84 percent. However, like Vasculour-D grafts, crimped grafts which preserve the crimp after implantation was significantly thicker at the internal valley than other grafts. Based on the findings of this experimental study non-crimped velour grafts were considered to be best fit for small-caliber artery implantation.

  2. EXPERIMENTAL STUDY OF INFORMAL NORMS OF URBAN COLORISTICS

    Directory of Open Access Journals (Sweden)

    Yulia Alexandrowna Griber

    2017-02-01

    Full Text Available The objective of the study was informal social norms of urban culture. The paper contains the detailed description of the experimental situation and the main steps of the field research, focused on the observance of informal social norms in the sphere of urban coloristics. The experiment was conducted in three districts of Smolensk (Russia – Leninskiy, Zadneprovskiy and Promyshlennyy. Particular attention was paid to the analysis of the results of the field research, including evaluation of reaction of participants (residents of multi-storied houses, breakers of informal norms of urban coloristics (experimenters and casual experiment witnesses (neighbors and passersby. In addition, the accuracy of results “forecasting”, done before the beginning of the experiment, is analyzed. The research was conducted using the methodology of breaking experiment that is one of the most provocative ways of studying informal norms in sociology and social psychology. The experiment allowed to draw a number of important conclusions. It showed that urban coloristics is regulated by strict informal norms, that are not noticed by citizens until a violation occurs. The power of informal norms is significantly underestimated by citizens, and their break causes a negative reaction and protest. The most important contribution to the study of informal norms of urban culture was the comparison of the reaction degree by men and women, by the residents of different districts (central, residential or blue-collar neighborhoods, by different age groups.

  3. Experimental study of Coal Pyrolysis 1.: Review of the experimental information from the literature

    International Nuclear Information System (INIS)

    Hugony, F.; Migliavacca, G.

    2007-01-01

    A brief analysis of some of the main experimental works published in the past decades about coal pyrolysis is here reported. In particular the results of some series of experiments are cited and reported in details, coming from the activity of some important international research teams; they supply a survey wide and complete enough of the different operating and experimental conditions proposed in this field. With the aim of giving a comparison benchmark for the original experimental data published in the companion paper of this series and in order to grant a good support to the validation of the predictive models of coal devolatilization [it

  4. Experimental study of mass boiling in a porous medium model

    International Nuclear Information System (INIS)

    Sapin, Paul

    2014-01-01

    This manuscript presents a pore-scale experimental study of convective boiling heat transfer in a two-dimensional porous medium. The purpose is to deepen the understanding of thermohydraulics of porous media saturated with multiple fluid phases, in order to enhance management of severe accidents in nuclear reactors. Indeed, following a long-lasting failure in the cooling system of a pressurized water reactor (PWR) or a boiling water reactor (BWR) and despite the lowering of the control rods that stops the fission reaction, residual power due to radioactive decay keeps heating up the core. This induces water evaporation, which leads to the drying and degradation of the fuel rods. The resulting hot debris bed, comparable to a porous heat-generating medium, can be cooled down by reflooding, provided a water source is available. This process involves intense boiling mechanisms that must be modelled properly. The experimental study of boiling in porous media presented in this thesis focuses on the influence of different pore-scale boiling regimes on local heat transfer. The experimental setup is a model porous medium made of a bundle of heating cylinders randomly placed between two ceramic plates, one of which is transparent. Each cylinder is a resistance temperature detector (RTD) used to give temperature measurements as well as heat generation. Thermal measurements and high-speed image acquisition allow the effective heat exchanges to be characterized according to the observed local boiling regimes. This provides precious indications precious indications for the type of correlations used in the non-equilibrium macroscopic model used to model reflooding process. (author) [fr

  5. Experimental study of mixed ferromagnetic spin glass systems

    International Nuclear Information System (INIS)

    Mirebeau, I.

    1987-01-01

    The mixed ferromagnetic spin glass systems are characterized by a distribution of positive and negative exchange interactions whose maximum occurs at a positive value. We have undertaken an experimental study of amorphous (Fe 1-x Mn x ) .75 PBA1, polycrystalline and monocrystalline Ni 1-x Mn x and Au 1-x Fe x alloys. By Moessbauer effect, magnetization and neutron scattering, we show that below a ''canting'' temperature T K , spin components transverse to the mean magnetization become frozen. Small angle neutron scattering studies with an applied field show a magnetic ''structure'' i.e. the intensity exhibits a maximum at a finite q value for temperatures below T K . This structure has been studied as a function of temperature, applied field and concentration using both small angle neutron scattering and 3 axis spectrometry where we separate the elastic from the inelastic components. Possible interpretations of this new structure will be given [fr

  6. Conceptual design study of fusion experimental reactor (FY86 FER)

    International Nuclear Information System (INIS)

    Seki, Yasushi; Iida, Hiromasa; Honda, Tsutomu.

    1987-08-01

    This report describes the study on safety for FER(Fusion Experimental Reactor) which has been designed as a next step machine to the JT-60. Though the final purpose of this study is to have an image of design base accident, maximum credible accident and to assess their risk or probability, etc., as FER plant system, the emphasis of this years study is placed on fuel-gas circulation system where the tritium inventory is maximum. This report consists of two chapters. The first chapter of this report summaries the FER system and describes FMEA(Failure Mode and Effect Analysis) and related accident progression sequence for FER plant system as a whole. The second chapter of this report is focused on fuel-gas circulation system including the purification, isotope separation system and storage system. Here, probability of risk is assessed by the probabilistic risk analysis (PRA) procedure based on FMEA, ETA and FTA. (author)

  7. Experimental study of ion-induced nucleation by radon decay

    International Nuclear Information System (INIS)

    He, F.; Hopke, P.K.

    1993-01-01

    In the environment, the presence of ions from natural radioactivity may increase the rate of new particle formation through ion-induced nucleation. A thermal diffusion cloud chamber (TDCC) has been built to experimentally study ion-induced nucleation where the ions are produced by gaseous radioactive sources. The critical supersaturation values and nucleation rates for methanol, ethanol, 1-propanol, and 1-butanol vapors on ions produced within the volume of the chamber by alpha decay of 222 Rn have been measured quantitatively at various radioactivity concentrations and supersaturations. The presence of ion tracks and the effect of an external electric field were also investigated. The alpha tracks and ion-induced nucleation formed by 222 Rn decay become visible at the critical supersaturation that is below the value needed for homogeneous nucleation. At this supersaturation, the nucleation rates increase substantially with increasing 222 Rn at low activity concentrations, but attain limiting values at higher concentrations. The experimental results indicate that the ionization by radon decay will promote ion-cluster formation and lower the free energy barriers. The formation of visible droplets is strongly dependent on the supersaturation. This study also confirms that the external electric field has a significant effect on the observed rates of nucleation

  8. Biofouling in forward osmosis systems: An experimental and numerical study.

    Science.gov (United States)

    Bucs, Szilárd S; Valladares Linares, Rodrigo; Vrouwenvelder, Johannes S; Picioreanu, Cristian

    2016-12-01

    This study evaluates with numerical simulations supported by experimental data the impact of biofouling on membrane performance in a cross-flow forward osmosis (FO) system. The two-dimensional numerical model couples liquid flow with solute transport in the FO feed and draw channels, in the FO membrane support layer and in the biofilm developed on one or both sides of the membrane. The developed model was tested against experimental measurements at various osmotic pressure differences and in batch operation without and with the presence of biofilm on the membrane active layer. Numerical studies explored the effect of biofilm properties (thickness, hydraulic permeability and porosity), biofilm membrane surface coverage, and biofilm location on salt external concentration polarization and on the permeation flux. The numerical simulations revealed that (i) when biofouling occurs, external concentration polarization became important, (ii) the biofilm hydraulic permeability and membrane surface coverage have the highest impact on water flux, and (iii) the biofilm formed in the draw channel impacts the process performance more than when formed in the feed channel. The proposed mathematical model helps to understand the impact of biofouling in FO membrane systems and to develop possible strategies to reduce and control biofouling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Thermochemistry of sarcosine and sarcosine anhydride: Theoretical and experimental studies

    International Nuclear Information System (INIS)

    Amaral, Luísa M.P.F.; Santos, Ana Filipa L.O.M.; Ribeiro da Silva, Maria das Dores M.C.; Notario, Rafael

    2013-01-01

    Highlights: ► Study on the Energetics of the sarcosine and sarcosine anhydride. ► Experimental and computational thermochemistry of sarcosine and its anhydride. ► Ab initio calculations for two amino acid derivatives by G3(MP2)//B3LYP method. -- Abstract: The standard molar enthalpies of formation, in the gaseous phase, at T = 298.15 K, of sarcosine, −(388.0 ± 1.0) kJ · mol −1 , and sarcosine anhydride, −(334.5 ± 1.6) kJ · mol −1 , were calculated by combining, for each compound, the standard molar enthalpy of formation, in the crystalline phase, and the standard molar enthalpy of sublimation, derived from measurements of the standard massic energies of combustion by static bomb combustion calorimetry, and from measurements of vapour pressures by the Knudsen mass-loss effusion method, respectively. The standard (p o = 0.1 MPa) molar enthalpies, entropies and Gibbs functions of sublimation, at T = 298.15 K, were also calculated. A theoretical study at the G3 and G4 levels has been carried out, and the calculated enthalpies of formation have been compared with the experimental ones

  10. Experimental study on embedment effect of foundation, 2

    International Nuclear Information System (INIS)

    Ohtomo, Keizo; Toma, Junichi; Hashimoto, Koichi; Hanada, Kazutake; Ueshima, Teruyuki; Yajima, Hiroshi

    1986-01-01

    In order to make clear the dynamic behavior of a embeded foundation on the quarternary ground experimentally, a series of forced vibration tests and seismic observation on both the small foundation (4 x 4 x 3 m) and the embeded form larger scale foundation of the shaking table (16 x 16 x 7.7 m) were conducted at the same site. The purposes this study are evaluating the dynamic behavior and the characteristics of dynamic stiffness and damping of the larger foundation based on forced vibration tests, and applying them to the dynamic response analysis of variable embedded foundations. In this report, the authors first examine frequency dependent property and its theoretical tendency of dynamic stiffness and damping surrounding table foundation. And then, consider an applicability and point of discussion related with the some theories which influence the embedment effect, in contrast with the experimental datum of the model foundation are past studies on a embedment effect (JPDR, Large-Scale Foundation in Tadotsu). (author)

  11. Experimental study of swelling of irradiated solid methane during annealing

    International Nuclear Information System (INIS)

    Shabalin, E.; Fedorov, A.; Kulagin, E.; Kulikov, S.; Melikhov, V.; Shabalin, D.

    2008-01-01

    Solid methane, notwithstanding its poor radiation properties, is still widely in use at pulsed neutron sources. One of the specific problems is radiolytic hydrogen gas pressure on the walls of a methane chamber during annealing of methane. Results of experimental study of this phenomenon under fast neutron irradiation with the help of a specially made low temperature irradiation rig at the IBR-2 pulsed reactor are presented. Peak pressure on the wall of the experimental capsule during heating of a sample irradiated at 23-35 K appeared to have a maximum of 27 bar at the absorbed dose 20 MGy, and then falls down with higher doses. Pressure always reached its peak value within the temperature range 72-79 K. Generally, three phases of methane swelling during heating can be distinguished, each characterized by proper rate and intensity. Results of this study were accounted for in design of the solid methane moderator of the second target station of the ISIS facility (England)

  12. Experimental Study on Abrasive Waterjet Polishing of Hydraulic Turbine Blades

    International Nuclear Information System (INIS)

    Khakpour, H; Birglenl, L; Tahan, A; Paquet, F

    2014-01-01

    In this paper, an experimental investigation is implemented on the abrasive waterjet polishing technique to evaluate its capability in polishing of surfaces and edges of hydraulic turbine blades. For this, the properties of this method are studied and the main parameters affecting its performance are determined. Then, an experimental test-rig is designed, manufactured and tested to be used in this study. This test-rig can be used to polish linear and planar areas on the surface of the desired workpieces. Considering the number of parameters and their levels, the Taguchi method is used to design the preliminary experiments. All experiments are then implemented according to the Taguchi L 18 orthogonal array. The signal-to-noise ratios obtained from the results of these experiments are used to determine the importance of the controlled polishing parameters on the final quality of the polished surface. The evaluations on these ratios reveal that the nozzle angle and the nozzle diameter have the most important impact on the results. The outcomes of these experiments can be used as a basis to design a more precise set of experiments in which the optimal values of each parameter can be estimated

  13. Experimental and analytical study of natural circulation in square loop

    International Nuclear Information System (INIS)

    Moorthi, A.; Prem Sai, K.; Ravi, K.V.

    2015-01-01

    The nuclear safety under station blackout conditions is a major concern in the design of the nuclear reactors. In the case of existing reactors, the heat removal capability of cooling systems under natural circulation conditions is to be ascertained by experiments/analysis. This will ensure the long term core cooling and thereby, the safety of reactor core. Natural circulation occurs when the heat sink is at a higher elevation compared with the heat source. In case, the heat source and the sink are nearly at the same elevation, the difference in the elevations of their thermal centres can provide the elevation head required for natural circulation. An experimental study of natural circulation in the above geometry was carried out. The effect of flow resistance, Heat Source strength (heater power) and elevation difference between the source and the sink on the heat transfer were studied. The results of the experiments were analysed using RELAP5/MOD 3.2 and a good match between the experimental data and RELAP5 predictions is observed. (author)

  14. Biofouling in forward osmosis systems: An experimental and numerical study

    KAUST Repository

    Bucs, Szilard

    2016-09-20

    This study evaluates with numerical simulations supported by experimental data the impact of biofouling on membrane performance in a cross-flow forward osmosis (FO) system. The two-dimensional numerical model couples liquid flow with solute transport in the FO feed and draw channels, in the FO membrane support layer and in the biofilm developed on one or both sides of the membrane. The developed model was tested against experimental measurements at various osmotic pressure differences and in batch operation without and with the presence of biofilm on the membrane active layer. Numerical studies explored the effect of biofilm properties (thickness, hydraulic permeability and porosity), biofilm membrane surface coverage, and biofilm location on salt external concentration polarization and on the permeation flux. The numerical simulations revealed that (i) when biofouling occurs, external concentration polarization became important, (ii) the biofilm hydraulic permeability and membrane surface coverage have the highest impact on water flux, and (iii) the biofilm formed in the draw channel impacts the process performance more than when formed in the feed channel. The proposed mathematical model helps to understand the impact of biofouling in FO membrane systems and to develop possible strategies to reduce and control biofouling. © 2016 Elsevier Ltd

  15. Experimental and numerical studies of rotating drum grate furnace

    Directory of Open Access Journals (Sweden)

    Basista Grzegorz

    2017-01-01

    Full Text Available Waste material from the meat industry can be taken into account as a biofuel. Studies confirm, that calorific value is higher and ash content is lower comparing to some conventional fuels. EU directives regulate details of thermal disposal of the waste material from the meat industry - especially in range of the process temperature and time of the particle presence in area of the combustion zone. The paper describes design of the rotating drum grate stove, dedicated to thermal disposal of the meat wastes as well as solid biomass (pellet, small bricket, wood chips combustion. Device has been developed in frames of cooperation between AGH University of Science and Technology (Krakow, Poland and producer focused on technologies of energy utilization of biomass in distributed generation. Results of measurements of selected operational parameters performed during startup of the furnace have been presented and discussed. Furthermore, numerical model of the combustion process has been developed to complement experimental results in range of the temperature and oxygen distribution in the area of the combustion chamber. ANSYS CFX solver has been applied to perform simulations including rotational domain related with specifics of operation of the device. Results of numerical modelling and experimental studies have been summarized and compared.

  16. A study on the establishment of severe accident experimental facility

    International Nuclear Information System (INIS)

    Yoo, Kun Joong; Kim, Sang Baek; Kim, In Sik; Nho, Ki Man; Bark, Rae Joon; Park, Chun Kyeong; Sim, Seok Koo; Lee, Seong Jae; Chung, Moon Ki; Cho, Yeong Ro; Chun, Shee Yeong

    1994-07-01

    Significant progress has been achieved during this year of the project. Planned DCH experiments on the sensitivity of the cavity geometry factors and the cavity capture volume effects were performed using the HPME facility for Kori-1/2 and YGN-3/4 cavity scale models. The Crust Formation Test Facility has been completed. Preliminary calculations were performed to predict test results. The experiments of the crust formation on the simulant and its heat transfer characteristic were performed to investigate the effects of coolant injection methods, bottom heating boundary surface temperatures, coolant temperatures and coolant flow rates. The design of the FCI Test Facility has been completed and the procurement of the materials is in progress. Also, the steam condensation experiment on the vertical containment walls and the research on the development of measuring techniques of the particle sizes and velocities are in progress as planned. Through international research collaboration with USNRC and CEA Cadarache, information of the experimental research on the severe fuel damage has been gathered and analyzed. Preliminary planning of the second phase tests has been launched this year. This study proposes the scope of the second phase and the strategy to implement the proposed second phase experimental program. This study also proposes a strategy to establish building blocks and infrastructure for the severe accident research in Korea. (Author)

  17. Experimental study of camel powered electricity generation unit

    Science.gov (United States)

    Jakhar, O. P.; Choudhary, Rahul Raj; Budaniya, Mukesh; Kumar, Ashish

    2018-05-01

    Developing nations are facing a huge gap in generation and demand of electricity across the world. In present scenario the demand of electricity is increasing day by day and the shortfall of electricity has become one of the major obstructions in the development of rural areas. There is a big gap between electricity supply and demand. In India it is very difficult that to give twenty four hours electric supply in rural areas. The traditional use of camel as draught animal, for the purpose of transport of goods and agricultural work, has been drastically reduced during last few decades, due to advancements and cheaper availability of mechanical machineries. In this research paper we experimentally studied the camel powered electricity generation system at National Research Centre on Camels (NRCC) Bikaner. Camel Energy in form of high torque low speed can be converted into low torque high speed through motion converting system i.e. gear and pulley mechanism for high RPM output. This high RPM (more than 3000) output is used for electricity generation. The electricity generated can be used directly or stored in the battery and later may be used whenever it is required either for DC light or AC light using inverter. According to experimental study a camel can comfortably generate electricity up to 1KW by rotating shaft. The complete set up for electricity generation using camel power has been designed, developed and physically commissioned at National Research Centre on Camels (NRCC) Bikaner.

  18. Experimental study on generation of large area uniform electron beam

    International Nuclear Information System (INIS)

    Tang Ying; Yi Aiping; Liu Jingru; Qian Hang; Huang Xin; Yu Li; Su Jiancang; Ding Zhenjie; Ding Yongzhong; Yu Jianguo

    2007-01-01

    In the experiment of gas laser pumped by electron beam, large area uniform electron beam is important to generate high efficiency laser output. The experimental study on generation of large area uniform electron beam with SPG-200 pulsed power generator is introduced. SPG-200 is an all-solid-state components pulsed power generator based on SOS, and its open voltage is more than 350 kV. The cathode have the area of 24 mm x 294 mm, and the anode-cathode(A-C)gap spacing is adjustable from 0 to 49 mm. The electron beam of cathode emission is transported to the laser chamber through the diode pressure foil, which sepa-rates the vacuum chamber from the laser chamber. Velvet and graphite cathodes are studied, each generates large area electron beam. The diode parameters are presented, and the uniformity of e-beam is diagnosed. The experimental results show that the diode voltage of the graphite cathode is 240-280 kV, and the diode current is 0.7-1.8 kA. The diode voltage of the velvet cathode is 200-250 kV, and the diode current is 1.5-1.7 kA. The uniformity of the velvet cathode emission is better than that of the graphite cathode. (authors)

  19. Experimental study on concrete shear wall behavior under seismic loading

    International Nuclear Information System (INIS)

    Gantenbein, F.; Queval, J.C.; Epstein, A.; Dalbera, J.

    1991-01-01

    An experimental program has been undertaken on the dynamic behavior of shear walls with and without openings. The experimental set-up, the test program and the main results will be detailed in the paper

  20. Experimental and analytical study of the sputtering phenomena

    International Nuclear Information System (INIS)

    Howard, P.A.

    1976-03-01

    One form of the sputtering phenomena, the heat-transfer process that occurs when an initially hot vertical surface is cooled by a falling liquid film, was examined from a new experimental approach. The sputtering front is the lowest wetted position on the vertical surface and is characterized by a short region of intense nucleate boiling. The sputtering front progresses downward at nearly a constant rate, the surface below the sputtering front being dry and almost adiabatic. This heat-transfer process is of interest in the analysis of some of the performance aspects of emergency core-cooling systems of light-water reactors. An experimental apparatus was constructed to examine the heat-transfer characteristics of a sputtering front. In the present study, a heat source of sufficient intensity was located immediately below the sputtering front, which prevented its downward progress, thus permitting detailed measurements of steady-state surface temperatures throughout a sputtering front. Experimental evidence showed the sputtering front to correspond to a critical heat-flux (CHF) phenomenon. Data were obtained with water flow rates of 350-1600 lb/sub m//hr-ft and subcoolings of 40-140 0 F on a 3 / 8 -in. solid copper rod at 1 atm. A two-dimensional analytical model was developed to describe a stationary sputtering front where the wet-dry interface corresponds to a CHF phenomena and the dry zone is adiabatic. This model is nonlinear because of the temperature dependence of the heat-transfer coefficient in the wetted region and has yielded good agreement with data. A simplified one-dimensional approximation was developed which adequately describes these data. Finally, by means of a coordinate transformation and additional simplifying assumptions, this analysis was extended to analyze moving sputtering fronts, and reasonably good agreement with reported data was shown

  1. Impact of an Innovative Classroom-Based Lecture Series on Residents’ Evaluations of an Anesthesiology Rotation

    Directory of Open Access Journals (Sweden)

    Pedro Tanaka

    2016-01-01

    Full Text Available Introduction. Millennial resident learners may benefit from innovative instructional methods. The goal of this study is to assess the impact of a new daily, 15 minutes on one anesthesia keyword, lecture series given by faculty member each weekday on resident postrotation evaluation scores. Methods. A quasi-experimental study design was implemented with the residents’ rotation evaluations for the 24-month period ending by 7/30/2013 before the new lecture series was implemented which was compared to the 14-month period after the lecture series began on 8/1/2013. The primary endpoint was “overall teaching quality of this rotation.” We also collected survey data from residents at clinical rotations at two other different institutions during the same two evaluation periods that did not have the education intervention. Results. One hundred and thirty-one residents were eligible to participate in the study. Completed surveys ranged from 77 to 87% for the eight-question evaluation instrument. On a 5-point Likert-type scale the mean score on “overall teaching quality of this rotation” increased significantly from 3.9 (SD 0.8 to 4.2 (SD 0.7 after addition of the lecture series, whereas the scores decreased slightly at the comparison sites. Conclusion. Rotation evaluation scores for overall teaching quality improved with implementation of a new structured slide daily lectures series.

  2. Experimental Study of the WEPTOS Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Marchalot, Tanguy

    This report presents the results of an experimental study on the power conversion capabilities and structural loads of the WEPTOS wave energy converter. The investigation focuses mainly at identifying the performance of the WEPTOS prototype in a wide range of production wave states...... and at the mooring forces and structural bending moments in extreme wave conditions, in order to estimate the performance and structural loads of larger WEPTOS machines being located at various offshore locations of interest. The following aspects were the main subjects of investigation: Performance of the prototype...... under a constant and linear PTO loading, the opening angle of the device, the effect of alterations to the wave conditions, and mooring forces and structural bending moments in production and extreme wave states. During the study, a highly realistic scale model was supplied by the client, WEPTOS, which...

  3. Experimental Study on the Langlee Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Weisz, A.

    This report presents the results of an experimental study of the wave energy converting abilities of the Langlee wave energy converter (WEC). It focused mainly on evaluating the power generating capabilities of the device, including investigations of the following issues: Scaling ratiosPTO loadingWave...... height and wave period dependencyOblique incoming waves and directional spreading of waves (3D waves)Damping platesMooring forces and fixed structure setupPitch, surge and heave motion During the study the model supplied by the client (Langlee Wave Power AS) has been heavily instrumented - up to 23...... different instruments was deployed to measure and record data. Tests were performed at scales of 1:30 and 1:20 based on the realized reference wave states....

  4. Experimental Study of the Weptos Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Larsen, Tommy

    2012-01-01

    This paper presents the power performance results of the experimental study of the WEPTOS wave energy converter (WEC). This novel device combines an established and efficient wave energy absorbing mechanism with an adjustable structure that can regulate the amount of incoming wave energy and reduce...... loads in extreme wave conditions. This A-shaped floating structure absorbs the energy in the waves through a multitude of rotors, the shape of which is based on the renowned Salter’s Duck. These rotors pivot around a common axle, one for each leg of the structure, to which the rotors transfer...... the absorbed wave energy and which is connected to a common power take off system (one for each leg). The study investigates the performance of the device in a large range of wave states and estimates the performance in terms of mechanical power available to the power take off system of the WEPTOS WEC for two...

  5. Experimental study of EHD pseudo-dropwise condensation

    International Nuclear Information System (INIS)

    Yabe, A.; Taketani, T.; Yoshizawa, Y.; Sunada, K.

    1991-01-01

    This paper reports that in order to realize a higher performance heat pump, an electrohydrodynamical (EHD) condenser utilizing a combination of two kinds of EHD phenomena has been researched. In this study, to maximize the augmentation effect, an experimental study has been carried out to clarify the details of an EHD pseudo-dropwise condensation. The diameter of the drops has decreased with the increase of the electric field. The condensation heat transfer coefficients have increased in proportion to the electric field strength, realizing the maximum local heat transfer coefficients of over 9000 W/m 2 K for CFC113 and over 11000W/m 2 K for HCFC123. Furthermore, the heat transfer coefficients have become the same for the same electric field strength, independent of the surface temperature of the heat transfer plate, if the amount of the falling condensate is the same

  6. Experimental studies of oxidic molten corium-vessel steel interaction

    International Nuclear Information System (INIS)

    Bechta, S.V.; Khabensky, V.B.; Vitol, S.A.; Krushinov, E.V.; Lopukh, D.B.; Petrov, Yu.B.; Petchenkov, A.Yu.; Kulagin, I.V.; Granovsky, V.S.; Kovtunova, S.V.; Martinov, V.V.; Gusarov, V.V.

    2001-01-01

    The experimental results of molten corium-steel specimen interaction with molten corium on the 'Rasplav-2' test facility are presented. In the experiments, cooled vessel steel specimens positioned on the molten pool bottom and uncooled ones lowered into the molten pool were tested. Interaction processes were studied for different corium compositions, melt superheating and in alternative (inert and air) overlying atmosphere. Hypotheses were put forward explaining the observed phenomena and interaction mechanisms. The studies presented in the paper were aimed at the detection of different corium-steel interaction mechanisms. Therefore certain identified phenomena are more typical of the ex-vessel localization conditions than of the in-vessel corium retention. Primarily, this can be referred to the phenomena of low-temperature molten corium-vessel steel interaction in oxidizing atmosphere

  7. Experimental studies of oxidic molten corium-vessel steel interaction

    Energy Technology Data Exchange (ETDEWEB)

    Bechta, S.V. E-mail: niti-npc@sbor.net; Khabensky, V.B.; Vitol, S.A.; Krushinov, E.V.; Lopukh, D.B.; Petrov, Yu.B.; Petchenkov, A.Yu.; Kulagin, I.V.; Granovsky, V.S.; Kovtunova, S.V.; Martinov, V.V.; Gusarov, V.V

    2001-12-01

    The experimental results of molten corium-steel specimen interaction with molten corium on the 'Rasplav-2' test facility are presented. In the experiments, cooled vessel steel specimens positioned on the molten pool bottom and uncooled ones lowered into the molten pool were tested. Interaction processes were studied for different corium compositions, melt superheating and in alternative (inert and air) overlying atmosphere. Hypotheses were put forward explaining the observed phenomena and interaction mechanisms. The studies presented in the paper were aimed at the detection of different corium-steel interaction mechanisms. Therefore certain identified phenomena are more typical of the ex-vessel localization conditions than of the in-vessel corium retention. Primarily, this can be referred to the phenomena of low-temperature molten corium-vessel steel interaction in oxidizing atmosphere.

  8. Conceptual design study of fusion experimental reactor (FY86 FER)

    International Nuclear Information System (INIS)

    Saito, Ryusei; Kashihara, Shin-ichiro; Itoh, Shin-ichi

    1987-08-01

    This report describes the results of conceptual design study on plant systems for the Fusion Experimental Reactor (FY86 FER). Design studies for FER plant systems have been continued from FY85, especially for design modifications made in accordance with revisions of plasma scaling parameters and system improvements. This report describes 1) system construction, 2) site and reactor building plan, 3) repaire and maintenance system, 4) tritium circulation system, 5) heating, ventilation and air conditioning system, 6) tritium clean-up system, 7) cooling and baking system, 8) waste treatment and storage system, 9) control system, 10) electric power system, 11) site factory plan, all of which are a part of FY86 design work. The plant systems described in this report generally have been based on the FY86 FER (ACS Reactor) which is an one of the six candidates for FER. (author)

  9. An experimental study on thermal properties of composite insulation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Gyoung-Seok [Building and Urban Research Department, Korea Institute of Construction Technology, 2311 Daehwa-Dong, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do 411-712 (Korea); College of Architecture, Hanyang University, 17, Hangdang-Dong, Sungdong-Gu, Seoul 133-791 (Korea); Kang, Jae-Sik; Jeong, Young-Sun; Lee, Seung-Eon [Building and Urban Research Department, Korea Institute of Construction Technology, 2311 Daehwa-Dong, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do 411-712 (Korea); Sohn, Jang-Yeul [College of Architecture, Hanyang University, 17, Hangdang-Dong, Sungdong-Gu, Seoul 133-791 (Korea)

    2007-04-01

    In accordance with the insulation standards reinforced since 2001 and the compulsory standards on floor impact sound insulation that have been enforced since 2004, insulation materials for actual buildings have been converted to composite materials and new insulation materials have been released in the market. However, Korea is lagging behind the world in fundamental experimental studies and resources. In case of some composite insulation materials, there also have been problems of distorted performance occurring as a result of tests being conducted without having verification and evaluation on the accuracy and inaccuracy of such tests. Therefore, this study grasped the thermal properties of composite insulation materials using thermal conductivity test equipment by heat flux method, and performed quantitative evaluation on the measurement precision and uncertainty of composite materials. (author)

  10. Experimental study of rectenna coupling at low power level

    International Nuclear Information System (INIS)

    Douyère, A; Alicalapa, F; Lan Sun Luk, J-D; Rivière, S

    2013-01-01

    The experimental results presented in this paper focus on the performance of a rectenna array by studying the effect of mutual coupling between two rectennas. The measurements in several planes of the space are investigated and used to help us to define the minimum distance for future rectenna arrays that can be used at a low power density level. The single element chosen for the array is composed of a rectifier circuit and a CSPA (Circular Slot Patch Antenna). This study shows that at a distance greater than 6cm (λ/2) between two rectennas in reception, we observe that the DC received voltage is constant in the Y plane, while in the X plane, the DC received voltage remains constant whatever the distance. We deduce that these rectennas are uncoupled in this case. We can consider each rectenna like an independent system.

  11. Conceptual design study of Fusion Experimental Reactor (FY87FER)

    International Nuclear Information System (INIS)

    1988-05-01

    The design study of Fusion Experimental Reactor(FER) which has been proposed to be the next step fusion device has been conducted by JAERI Reactor System Laboratory since 1982 and by FER design team since 1984. This is the final report of the FER design team program and describes the results obtained in FY1987 (partially in FY1986) activities. The contents of this report consist of the reference design which is based on the guideline in FY1986 by the Subcomitees set up in Nuclear Fusion Council of Atomic Energy Commission of Japan, the Low-Physics-Risk reactor design for achieving physics mission more reliably and the system study of FER design candidates including above two designs. (author)

  12. Experimental study of radon and thoron diffusion through barriers

    Energy Technology Data Exchange (ETDEWEB)

    Durcik, M; Havlik, F [Inst. of Preventive and Clinical Medicine, 83301 Bratislava (Slovakia)

    1996-12-31

    The measurement results of diffusion parameters for radon (radon-222) and thoron (radon-220) through barriers, experimental equipment and theoretical background of diffusion are presented in this paper. The diffusion barriers are used for measuring radon and thoron by passive detectors in order to test the reduction techniques in houses. Six samples (filter paper, rubber, polyethylene, glass laminate, polypropylene) were studied for radon diffusion. The thickness barriers were from 0.012 mm to 2 mm, the diffusion area was 16 cm{sup 2} and the volume V{sub 2} was 30 dm{sup 3}. The diffusion constants D were obtained using given expressions and the data from measurements. The procedures used in experiments are useful for study of diffusion ability of radon and thoron in barriers and determination diffusion parameters from short term measurements. (J.K.). 2 figs., 1 tab., 3 refs.

  13. Experimental study of radon and thoron diffusion through barriers

    International Nuclear Information System (INIS)

    Durcik, M.; Havlik, F.

    1995-01-01

    The measurement results of diffusion parameters for radon (radon-222) and thoron (radon-220) through barriers, experimental equipment and theoretical background of diffusion are presented in this paper. The diffusion barriers are used for measuring radon and thoron by passive detectors in order to test the reduction techniques in houses. Six samples (filter paper, rubber, polyethylene, glass laminate, polypropylene) were studied for radon diffusion. The thickness barriers were from 0.012 mm to 2 mm, the diffusion area was 16 cm 2 and the volume V 2 was 30 dm 3 . The diffusion constants D were obtained using given expressions and the data from measurements. The procedures used in experiments are useful for study of diffusion ability of radon and thoron in barriers and determination diffusion parameters from short term measurements. (J.K.). 2 figs., 1 tab., 3 refs

  14. Meeting the requirements of both classroom-based and systemic assessment of mathematics proficiency: The potential of Rasch measurement theory

    Directory of Open Access Journals (Sweden)

    Tim Dunne

    2012-11-01

    Full Text Available The challenges inherent in assessing mathematical proficiency depend on a number of factors, amongst which are an explicit view of what constitutes mathematical proficiency, an understanding of how children learn and the purpose and function of teaching. All of these factors impact on the choice of approach to assessment. In this article we distinguish between two broad types of assessment, classroom-based and systemic assessment. We argue that the process of assessment informed by Rasch measurement theory (RMT can potentially support the demands of both classroom-based and systemic assessment, particularly if a developmental approach to learning is adopted, and an underlying model of developing mathematical proficiency is explicit in the assessment instruments and their supporting material. An example of a mathematics instrument and its analysis which illustrates this approach, is presented. We note that the role of assessment in the 21st century is potentially powerful. This influential role can only be justified if the assessments are of high quality and can be selected to match suitable moments in learning progress and the teaching process. Users of assessment data must have sufficient knowledge and insight to interpret the resulting numbers validly, and have sufficient discernment to make considered educational inferences from the data for teaching and learning responses.

  15. Does training of second-language word recognition skills affect reading comprehension? An experimental study

    NARCIS (Netherlands)

    Fukkink, R.G.; Hulstijn, J.H.; Simis, A.

    2005-01-01

    Two classroom-based experiments investigated automatization of lexical access in a second language (L2) with a computer-based training, involving a Grade 8 population in the Netherlands, with Dutch first language (L1) and intermediate knowledge of L2 English. Results of the first experiment showed

  16. Oak Ridge Tokamak experimental power reactor study scoping report

    International Nuclear Information System (INIS)

    Roberts, M.

    1977-03-01

    This report presents the scoping studies performed as the initial part of the program to produce a conceptual design for a Tokamak Experimental Power Reactor (EPR). The EPR as considered in this study is to employ all systems necessary for significant electric power production at continuous high duty cycle operation; it is presently scheduled to be the final technological step before a Demonstration Reactor Plant (Demo). The scoping study tasks begin with an exploration and identification of principal problem areas and then concentrate on consideration and evaluation of alternate design choices for each of the following major systems: Plasma Engineering and Physics, Nuclear, Electromagnetics, Neutral Beam Injection, and Tritium Handling. In addition, consideration has been given to the integration of these systems and requirements arising out of their incorporation into an EPR. One intent of this study is to document the paths explored in search of the appropriate EPR characteristics. To satisfy this intent, the explorations are presented in chart form outlining possible options in key areas with extensive supporting footnotes. An important result of the scoping study has been the development and definition of an EPR reference design to serve as (1) a common focus for the continuing design study and (2) a guide for associated development programs. In addition, the study has identified research and development requirements essential to facilitate the successful conceptual design, construction, and operation of an EPR

  17. An experimental study on suspended sodium droplet combustion (2)

    International Nuclear Information System (INIS)

    Sato, Kenji

    2004-03-01

    As part of studies for phenomenological investigation of sodium droplet burning behavior, in our previous experimental studies for suspended single sodium droplet, behavior of ignition process and succeeding combustion, ignition delay time, and droplet temperature history had been investigated. In the present study, by using 4 mm diam. suspended sodium droplet, combustion experiments were performed for extended free-stream velocity range of dry air up to 200 cm/s, and for the initial droplet temperature T i =300degC and 400degC, and the effects of the free-stream velocity and initial droplet temperature on the ignition/burning behavior and ignition delay time were examined by using high speed video camera. The obtained experimental results are as follows: (1) Ignition phenomena of suspended spherical shape droplet were observed for all examined experimental conductions except the case of free-stream velocity U=200 cm/s at 300degC, where detachment of droplet from the support due to strained oxide film occurred. (2) The ignition delay time defined as the time to evolution of orange-light emitting zone or flame zone decreases with the increase of the free-stream velocity or of initial droplet temperature. Examples of typical ignition delay time are 0.68 s at U=20 cm/s, 0.52 s at U=100 cm/s, and 0.37 s at 200 cm/s for T i =400degC. (3) The orange-light emission at the moment of ignition occurs simultaneously over whole surface except the top region of the droplet. The intensity of the emission at the moment of ignition takes its maximum at the bottom region or upstream region of the droplet, and the emission intensity during the stable burning period increases with the increase of U. (4) When T i is 300degC, formation of temporal multiple short projections are observed before ignition for all examined free-stream velocities. The projections often do not disappear before ignition when the velocity is relatively high. (5) The layer or cloud composed of aerosol is formed

  18. Experimental study of transient paths to the extinction in sonoluminescence.

    Science.gov (United States)

    Urteaga, Raúl; Dellavale, Damián; Puente, Gabriela F; Bonetto, Fabián J

    2008-09-01

    An experimental study of the extinction threshold of single bubble sonoluminescence in an air-water system is presented. Different runs from 5% to 100% of air concentrations were performed at room pressure and temperature. The intensity of sonoluminescence (SL) and time of collapse (t(c)) with respect to the driving were measured while the acoustic pressure was linearly increased from the onset of SL until the bubble extinction. The experimental data were compared with theoretical predictions for shape and position instability thresholds. It was found that the extinction of the bubble is determined by different mechanisms depending on the air concentration. For concentrations greater than approximately 30%-40% with respect to the saturation, the parametric instability limits the maximum value of R(0) that can be reached. On the other hand, for lower concentrations, the extinction appears as a limitation in the time of collapse. Two different mechanisms emerge in this range, i.e., the Bjerknes force and the Rayleigh-Taylor instability. The bubble acoustic emission produces backreaction on the bubble itself. This effect occurs in both mechanisms and is essential for the correct prediction of the extinction threshold in the case of low air dissolved concentration.

  19. An experimental study on soil-structure interaction effects

    International Nuclear Information System (INIS)

    Mita, Akira; Kumagai, Shigeru

    1989-01-01

    The soil-structure interaction effects play an important role in the earthquake response of large scale structures such as nuclear power plants. Recent decades, many experimental and analytical studies have been conducted. Even though sophisticated analytical tools are ready to use, complicated soil-structure interaction problems such as those with a complex geometry can not be solved yet. For such problems a laboratory experiment is a powerful alternative. In the laboratory experiment, a device to absorb the reflected waves is always necessary to be attached on the boundaries of the soil model to simulate the semi-infiniteness of the actual ground. But unfortunately absorbing devices currently available are far from satisfactory. In this paper, a new experimental method is employed for soil-structure interaction problems to simulate the semi-infiniteness of the actual ground. The present method utilizes the characteristics of transient response to an impulse load so that no special treatment on the boundaries of the soil model is required. This technique is applicable to a linear elastic system whose impulse response decreases to a small enough value before observing the reflected waves. (author)

  20. Numerical and Experimental Study of Amplitude Modulated Positive Corona Discharge

    Directory of Open Access Journals (Sweden)

    Pablo Martín GOMEZ

    2014-12-01

    Full Text Available The electrical behavior of a modulated positive corona discharge loudspeaker was studied. A coaxial transducer in air was built using a central copper wire of 75 mm radius (inner electrode and a perforated tube of 11 mm (outer electrode. A high voltage DC supply provided the bias current and a sinusoidal signal was superimposed to measure the discharge admittance. The experimental results could not be matched to previously reported equivalent circuits with fixed components. Using the basic equations that describe the ion motion, a numerical model was proposed. The computed values matched well the experimental data and suggested an equivalent circuit composed of frequency dependent conductance and capacitance. This dependence is closely related to the ion travel time between electrodes (transit time. Simulations carried out at several inter-electrode distances could be synthesized in a single plot where the different results overlap and further emphasize the role of the transit time. This numerical model proved to be an efficient tool to simulate and design modulated corona transducers.

  1. Experimental Study of Interior Temperature Distribution Inside Parked Automobile Cabin

    Directory of Open Access Journals (Sweden)

    Issam Mohammed Ali Aljubury

    2015-03-01

    Full Text Available Temperature inside the vehicle cabin is very important to provide comfortable conditions to the car passengers. Temperature inside the cabin will be increased, when the car is left or parked directly under the sunlight. Experimental studies were performed in Baghdad, Iraq (33.3 oN, 44.4 oE to investigate the effects of solar radiation on car cabin components (dashboard, steering wheel, seat, and inside air. The test vehicle was oriented to face south to ensure maximum (thermal sun load on the front windscreen. Six different parking conditions were investigated. A suggested car cover was examined experimentally. The measurements were recorded for clear sky summer days started at 8 A.M. till 5 P.M. Results show that interior air temperature in unshaded parked car reaches 70oC and dashboard temperature can approach 100 oC. While, cardboard car shade inside the car not reduce the air temperature inside it. Suggested car cover with 1 cm part-down side windows reduced temperature of cabin components by 70 % in average compare to the base case.

  2. Experimental study of adsorption chiller driven by variable heat source

    Energy Technology Data Exchange (ETDEWEB)

    Wang, D.C.; Wang, Y.J.; Zhang, J.P.; Tian, X.L. [College of Electromechanical Engineering, Qingdao University, Qingdao 266071 (China); Wu, J.Y. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2008-05-15

    A silica gel-water adsorption chiller has been developed in recent years and has been applied in an air conditioning system driven by solar energy. The heat source used to drive the adsorption chiller is variable at any moment because the solar radiation intensity or the waste heat from engines varies frequently. An adsorption cooling system may be badly impacted by a variable heat source with temperature variations in a large range. In this work, a silica gel-water adsorption chiller driven by a variable heat source is experimentally studied. The influences of the variable heat source on the performance of the chiller are analyzed, especially for a continuous temperature increase process and a continuous temperature decrease process of the heat source. As an example, the dynamic characteristics of the heat source are also analyzed when solar energy is taken as the heat source of the adsorption chiller. According to the experimental results for the adsorption chiller and the characteristics of the heat source from solar energy, control strategies of the adsorption chiller driven by solar energy are proposed. (author)

  3. Design and experimental study on desulphurization process of ship exhaust

    Science.gov (United States)

    Han, Mingyang; Hao, Shan; Zhou, Junbo; Gao, Liping

    2018-02-01

    This desulfurization process involves removing sulfur oxides with seawater or alkaline aqueous solutions and then treating the effluent by aeration and pH adjustment before discharging it into the ocean. In the desulfurization system, the spray tower is the key equipment and the venturi tubes are the pretreatment device. The two stages of plates are designed to fully absorb sulfur oxides in exhaust gases. The spiral nozzles atomize and evenly spray the desulfurizers into the tower. This study experimentally investigated the effectiveness of this desulfurization process and the factors influencing it under laboratory conditions, with a diesel engine exhaust used to represent ship exhaust. The experimental results show that this process can effectively absorb the SO2 in the exhaust. When the exhaust flow rate was 25 m3/h and the desulfurizer flow rate was 4 L/min, the sulfur removal efficiency (SRE) reached 99.7%. The flow rate, alkalinity, and temperature of seawater were found to have significant effects on the SRE. Adjusting seawater flow rate (SWR) and alkalinity within certain ranges can substantially improve the SRE.

  4. Alcohol and acute pancreatitis. An experimental study in the rat.

    Science.gov (United States)

    Jalovaara, P; Apaja, M

    1978-01-01

    The effect of chronic alcohol pretreatment and various pancreatobiliary secretions on the severity of experimental pancreatitis was studied in the rat. 95 rats were pretreated with ethanol (20% w/v, 1.1 ml/100 g body weight) five times weekly for 10 to 12 weeks by gastric intubation. 88 rats served as controls. Pancreatic lesions were produced by retograde injection of different pancreatobiliary secretions into the pancreatic ducts. The secretions were collected from both normal and chronically alcohol-fed rats, and each was used for induction of experimental pancreatitis in the control and alcohol pretreated rats. Bile obtained from normal rats was no more toxic to the pancreas than 0.9% saline solution, while bile obtained from the chronically alcohol-fed rats caused significantly more serious lesions to the pancreas than did normal rat bile. Bile-pancreatic juice (mixture of secretions at papilla of Vater) of normal and chronically alcohol-fed rats was as toxic as the bile of the alcohol-fed rats. Alcohol pretreatment had no significant effect on the severity of pancreatitis when control and alcohol-fed groups separately or the whole material according to pretreatment was examined. These results suggest that the metabolic effects of ethanol on the pancreas as such do not sensitize the pancreas to acute pancreatitis. An exogenous mechanism is required. The reflux of toxic alcoholic bile into the pancreas might act as an induction factor in acute alcohol pancreatitis.

  5. Method to deterministically study photonic nanostructures in different experimental instruments.

    Science.gov (United States)

    Husken, B H; Woldering, L A; Blum, C; Vos, W L

    2009-01-01

    We describe an experimental method to recover a single, deterministically fabricated nanostructure in various experimental instruments without the use of artificially fabricated markers, with the aim to study photonic structures. Therefore, a detailed map of the spatial surroundings of the nanostructure is made during the fabrication of the structure. These maps are made using a series of micrographs with successively decreasing magnifications. The graphs reveal intrinsic and characteristic geometric features that can subsequently be used in different setups to act as markers. As an illustration, we probe surface cavities with radii of 65 nm on a silica opal photonic crystal with various setups: a focused ion beam workstation; a scanning electron microscope (SEM); a wide field optical microscope and a confocal microscope. We use cross-correlation techniques to recover a small area imaged with the SEM in a large area photographed with the optical microscope, which provides a possible avenue to automatic searching. We show how both structural and optical reflectivity data can be obtained from one and the same nanostructure. Since our approach does not use artificial grids or markers, it is of particular interest for samples whose structure is not known a priori, like samples created solely by self-assembly. In addition, our method is not restricted to conducting samples.

  6. Experimental study on hollow structural component by explosive welding

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Mianjun, E-mail: dmjwl@163.com [PLA University of Science and Technology, Nanjing 210007 (China); Wei, Ling, E-mail: 386006087@qq.com [Tongda College, Nanjing University of Posts and Telecommunication, Nanjing 210007 (China); Hong, Jin [PLA University of Science and Technology, Nanjing 210007 (China); Ran, Hong [Southwestern Institute of Physics, Chengdu 610041 (China); Ma, Rui; Wang, Yaohua [PLA University of Science and Technology, Nanjing 210007 (China)

    2014-12-15

    Highlights: • This paper relates to a study on a thin double-layers hollow structural component by using an explosive welding technology. • This thin double-layer hollow structural component is an indispensable component required for certain core equipment of thermonuclear experimental reactor. • An adjusted explosive welding technology for manufacturing an inconel625 hollow structural component was developed which cannot be made by common technology. • The result shows that a metallurgical bonding was realized by the ribs and slabs of the hollow sheet. • The shearing strength of bonding interface exceeds that of the parent metal. - Abstract: A large thin-walled hollow structural component with sealed channels is required for the vacuum chamber of a thermonuclear experimental reactor, with inconel625 as its fabrication material. This hollow structural component is rarely manufactured by normal machining method, and its manufacture is also problematic in the field of explosive welding. With this in mind, we developed an adjusted explosive welding technology which involves a two-step design, setting and annealing technology. The joints were evaluated using optical microscope and scanning electron microscope, and a mechanical experiment was conducted, involving micro-hardness test, cold helium leak test and hydraulic pressure test. The results showed that a metallurgical bonding was realized by the ribs and slabs, and the shearing strength of the bonding interface exceeded that of the parent metal. Hence, the hollow structural component has a good comprehensive mechanical performance and sealing property.

  7. On the Numerical and Experimental Study of Spray Cooling

    Directory of Open Access Journals (Sweden)

    M.R. Guechi

    2013-12-01

    Full Text Available The spraying of an impinging jet is an effective way to cool heated surfaces. The objective of this study is to develop a numerical model to predict the heat transfer with phase change between a hot plate surface and a two-phase impinging jet. Different two-phase modeling approaches (Lagrangian and Eulerian methods are compared. The influence of the spray nozzle operating conditions and of the distance between the nozzle exit and the surface impact is analyzed. The numerical results are compared with measurements obtained on an experimental test bench. The confrontation numerical/experimental is carried out by comparing the distribution of temperature at the surface of the plate and the heat transfer coefficient. This comparison shows that it is the Eulerian model which seems most capable to take into account the evaporation of the droplets in contact with the heated plate. However, the simulation performed with this model show a strong dependence of the results to the turbulence model used.

  8. DEMT experimental and analytical studies on seismic isolation

    International Nuclear Information System (INIS)

    Gantenbein, F.; Buland, P.

    1989-01-01

    Work on seismic isolation has been performed in France for many years, and the isolation device developed by SPIE-BATIGNOLLES in collaboration with Electricite de France (EDF) has been incorporated in the design of pressurized-water reactor (PWR) nuclear power plants. This paper reviews the experimental and theoretical studies performed at CEA/DEMT related to the overall behavior of isolated structures. The experimental work consists of the seismic shaking-table tests of a concrete cylinder isolated by neoprene sliding pads, and the vibrational tests on the reaction mass of the TAMARIS seismic facility. The analytical work consists of the development of procedures for dynamic calculation methods: for soil-structure interaction where pads are placed between an upper raft and pedestals, for time-history calculations where sliding plates are used, and for fluid-structure interaction where coupled fluid and structure motions and sloshing modes are important. Finally, this paper comments on the consequences of seismic isolation for the analysis of fast breeder reactor (FBR) vessels. The modes can no longer be considered independent (SRSS Method leads to important errors), and the sloshing increases

  9. Experimental study of self-backlighting method for opacity

    International Nuclear Information System (INIS)

    Ding Yaonan; Yang Jiamin; Li Sanwei; Cao Leifeng; Wang Yaomei; Zhang Wenhai; Chen Bo; Yu Yanning; Wang Hongbin

    2001-01-01

    Self-backlighting method for opacity measurement has been suggested and studied, based on the actual condition of Xingguang II laser facility. An 80 J and 350 nm laser, which has a duration of about 700 ps, irradiates on a newly designed target and creates intense X-ray radiation acting as both heating source and backlighter source. The heated sample has been spatially imaged to obtain X-ray spectra from X-ray source region, transmission region and self-emission region of the sample at the same shot by spatially resolved transmission grating spectrometer in which dispersed X-ray is recorded by X-ray CCD. The samples are low-Z CH foam with density of 0.042 g/cm 3 , thickness of 42 μm and mid-Z Al with density of 2.7 g/cm 3 , thickness of 0.5 μm or 1.0 μm. Mass absorption coefficients of the heated sample as function of the photon energy have been obtained experimentally in the same shot. The spectra line emitted from the heated CH foam has also been measured by OHM crystal spectrometer, which has been used to determine the temperature of the sample. The experimental results for opacity of carbon have been discussed

  10. Experimental study on hollow structural component by explosive welding

    International Nuclear Information System (INIS)

    Duan, Mianjun; Wei, Ling; Hong, Jin; Ran, Hong; Ma, Rui; Wang, Yaohua

    2014-01-01

    Highlights: • This paper relates to a study on a thin double-layers hollow structural component by using an explosive welding technology. • This thin double-layer hollow structural component is an indispensable component required for certain core equipment of thermonuclear experimental reactor. • An adjusted explosive welding technology for manufacturing an inconel625 hollow structural component was developed which cannot be made by common technology. • The result shows that a metallurgical bonding was realized by the ribs and slabs of the hollow sheet. • The shearing strength of bonding interface exceeds that of the parent metal. - Abstract: A large thin-walled hollow structural component with sealed channels is required for the vacuum chamber of a thermonuclear experimental reactor, with inconel625 as its fabrication material. This hollow structural component is rarely manufactured by normal machining method, and its manufacture is also problematic in the field of explosive welding. With this in mind, we developed an adjusted explosive welding technology which involves a two-step design, setting and annealing technology. The joints were evaluated using optical microscope and scanning electron microscope, and a mechanical experiment was conducted, involving micro-hardness test, cold helium leak test and hydraulic pressure test. The results showed that a metallurgical bonding was realized by the ribs and slabs, and the shearing strength of the bonding interface exceeded that of the parent metal. Hence, the hollow structural component has a good comprehensive mechanical performance and sealing property

  11. Work-related symptoms and checkstand configuration: an experimental study.

    Science.gov (United States)

    Harber, P; Bloswick, D; Luo, J; Beck, J; Greer, D; Peña, L F

    1993-07-01

    Supermarket checkers are known to be at risk of upper-extremity cumulative trauma disorders. Forty-two experienced checkers checked a standard "market basket" of items on an experimental checkstand. The counter height could be adjusted (high = 35.5, low = 31.5 inches), and the pre-scan queuing area length (between conveyor belt and laser scanner) could be set to "near" or "far" lengths. Each subject scanned under the high-near, high-far, low-near, and low-far conditions in random order. Seven ordinal symptom scales were used to describe comfort. Analysis showed that both counter height and queuing length had significant effects on symptoms. Furthermore, the height of the subject affected the degree and direction of the impact of the checkstand configuration differences. The study suggests that optimization of design may be experimentally evaluated, that modification of postural as well as frequency loading may be beneficial, and that adjustability for the individual may be advisable.

  12. Experimental Study on Critical Power in a Hemispherical Narrow Gap

    International Nuclear Information System (INIS)

    Park, Rae-Joon; Ha, Kwang-Soon; Kim, Sang-Baik; Kim, Hee-Dong; Jeong, Ji-Hwan

    2002-01-01

    An experimental study of critical heat flux in gap (CHFG) has been performed to investigate the inherent cooling mechanism in a hemispherical narrow gap. The objectives of the CHFG test are to measure critical power from a critical heat removal rate through the hemispherical narrow gap using distilled water with experimental parameters of system pressure and gap width. The CHFG test results have shown that a countercurrent flow limitation (CCFL) brings about local dryout at the small edge region of the upper part and finally global dryout in a hemispherical narrow gap. Increases in the gap width and pressure lead to an increase in critical power. The measured values of critical power are lower than the predictions made by other empirical CHF correlations applicable to flat plate, annuli, and small spherical gaps. The measured data on critical power in the hemispherical narrow gaps have been correlated using nondimensional parameters with a range of approximately ±20%. The developed correlation has been expanded to apply the spherical geometry using the Siemens/KWU correlation

  13. Study of Formulation Variables Influencing Polymeric Microparticles by Experimental Design

    Directory of Open Access Journals (Sweden)

    Jitendra B. Naik

    2014-04-01

    Full Text Available The objective of this study was to prepare diclofenac sodium loaded microparticles by single emulsion [oil-in-water (o/w] solvent evaporation method. The 22 experimental design methodology was used to evaluate the effect of two formulation variables on microspheres properties using the Design-Expert® software and evaluated for their particle size, morphology, and encapsulation efficiency and in vitro drug release. The graphical and mathematical analysis of the design showed that the independent variables were a significant effect on the encapsulation efficiency and drug release of microparticles. The low magnitudes of error and significant values of R2 prove the high prognostic ability of the design. The microspheres showed high encapsulation efficiency with an increase in the amount of polymer and decrease in the amount of PVA in the formulation. The particles were found to be spherical with smooth surface. Prolonged drug release and enhancement of encapsulation efficiency of polymeric microparticles can be successfully obtained with an application of experimental design technique.

  14. Comparative studies on the ossification in several experimental animals

    International Nuclear Information System (INIS)

    Matsuoka, Osamu; Fukuda, Shun

    1978-01-01

    For estimating the risk of the bone seeking radionuclides in man, it is necessary to extrapolate the data of experimental animals to those of man. Detailed information on the biological stages of development, especially on bone growth of several experimental animals and of man is required for better extrapolation. Multi-species comparison of bone growth and ossification was carried out in several mammalian species such as mouse, rat, dog and monkey. The appearance, ossifying process and fusion of the secondary ossification centers in extremities were selected as indicators of the biological stage of bone. The observation of the secondary ossification centers was made by radiography. The maturity process of the secondary ossification centers in each animal was illustrated. The ossifying process of the secondary ossification center could be divided into the following three categories; (1) the acute ossification observed in mouse, rat, dog and monkey (2) the delayed ossification observed in mouse, rat, dog and monkey, (3) the incomplete ossification without complete fusion which is specific in mouse and rat, appeared and continued up to at least 27 weeks in mouse and up to 134 weeks in rat. The results of the study suggested that a mouse 17 weeks old, a rat 17 - 21 weeks old, a dog (beagle) 14 months old and a monkey about 6 years old may correspond to a man about 20 years old. (author)

  15. Experimental Study of Hysteretic Steel Damper for Energy Dissipation Capacity

    Directory of Open Access Journals (Sweden)

    Daniel R. Teruna

    2015-01-01

    Full Text Available This study aims to evaluate energy absorption capacity of hysteretic steel damper for earthquake protection of structures. These types of steel dampers are fabricated from mild steel plate with different geometrical shapes on the side part, namely, straight, concave, and convex shapes. The performance of the proposed device was verified experimentally by a series of tests under increasing in-plane cyclic load. The overall test results indicated that the proposed steel dampers have similar hysteretic curves, but the specimen with convex-shaped side not only showed stable hysteretic behavior but also showed excellent energy dissipation capabilities and ductility factor. Furthermore, the load-deformation relation of these steel dampers can be decomposed into three parts, namely, skeleton curve, Bauschinger part, and elastic unloading part. The skeleton curve is commonly used to obtain the main parameters, which describe the behavior of steel damper, namely, yield strength, elastic stiffness, and postyield stiffness ratio. Moreover, the effective stiffness, effective damping ratio, cumulative plastic strain energy, and cumulative ductility factor were also derived from the results. Finally, an approximation trilinear hysteretic model was developed based on skeleton curve obtained from experimental results.

  16. Experimental studies on ion mobility in xenon-trimethylamine mixtures

    Science.gov (United States)

    Trindade, A. M. F.; Encarnação, P. M. C. C.; Escada, J.; Cortez, A. F. V.; Neves, P. N. B.; Conde, C. A. N.; Borges, F. I. G. M.; Santos, F. P.

    2017-07-01

    In this paper we present experimental results for ion reduced mobilities (K0) in gaseous trimethylamine, TMA—(CH3)3N, and xenon-TMA mixtures for reduced electric fields E/N between 7.5 and 60 Td and in the pressure range from 0.5 to 10 Torr, at room temperature. Both in the mixtures and in pure TMA only one peak was observed in the time of arrival spectra, which is believed to be due to two TMA ions with similar mass, (CH3)3N+ (59 u) and (CH3)2CH2N+ (58 u), whose mobility is indistinguishable in our experimental system. The possibility of ion cluster formation is also discussed. In pure TMA, for the E/N range investigated, an average value of 0.56 cm2V-1s-1 was obtained for the reduced mobility of TMA ions. For the studied mixtures, it was observed that even a very small amount of gaseous TMA (~0.2%) in xenon leads to the production of the above referred TMA ions or clusters. The reduced mobility value of this ion or ions in Xe-TMA mixtures is higher than the value in pure TMA: around 0.8 cm2V-1s-1 for TMA concentrations from 0.2% to about 10%, decreasing for higher TMA percentages, eventually converging to the reduced mobility value in pure TMA.

  17. Experimental study of adsorption chiller driven by variable heat source

    International Nuclear Information System (INIS)

    Wang, D.C.; Wang, Y.J.; Zhang, J.P.; Tian, X.L.; Wu, J.Y.

    2008-01-01

    A silica gel-water adsorption chiller has been developed in recent years and has been applied in an air conditioning system driven by solar energy. The heat source used to drive the adsorption chiller is variable at any moment because the solar radiation intensity or the waste heat from engines varies frequently. An adsorption cooling system may be badly impacted by a variable heat source with temperature variations in a large range. In this work, a silica gel-water adsorption chiller driven by a variable heat source is experimentally studied. The influences of the variable heat source on the performance of the chiller are analyzed, especially for a continuous temperature increase process and a continuous temperature decrease process of the heat source. As an example, the dynamic characteristics of the heat source are also analyzed when solar energy is taken as the heat source of the adsorption chiller. According to the experimental results for the adsorption chiller and the characteristics of the heat source from solar energy, control strategies of the adsorption chiller driven by solar energy are proposed

  18. Experimental study of resonance crossing with a Paul trap

    Directory of Open Access Journals (Sweden)

    H. Takeuchi

    2012-07-01

    Full Text Available The effect of resonance crossing on beam stability is studied systematically by employing a novel tabletop experimental tool and a multiparticle simulation code. A large number of ions are confined in a compact linear Paul trap to reproduce the collective beam behavior. We can prove that the ion plasma in the trap is physically equivalent to a charged-particle beam propagating through a strong focusing channel. The plasma confinement force is quickly ramped such that the trap operating point traverses linear and nonlinear resonance stop bands. Assuming a nonscaling fixed field alternating gradient accelerator composed of many identical FODO cells, we measure how much ion losses occur under diverse conditions. It is experimentally and numerically demonstrated that too slow resonance crossing leads to significant ion losses as expected. Particular attention must be paid to the linear coherent resonance excited at a quarter-integer tune. When the beam intensity is high, this type of linear stop band can seriously affect the beam quality even for rather fast resonance crossing. A scaling law is given of the emittance growth caused by the quarter-integer resonance crossing.

  19. Experimental and numerical studies of micro PEM fuel cell

    Science.gov (United States)

    Peng, Rong-Gui; Chung, Chen-Chung; Chen, Chiun-Hsun

    2011-10-01

    A single micro proton exchange membrane fuel cell (PEMFC) has been produced using Micro-electromechanical systems (MEMS) technology with the active area of 2.5 cm2 and channel depth of about 500 µm. A theoretical analysis is performed in this study for a novel MEMS-based design of amicro PEMFC. Themodel consists of the conservation equations of mass, momentum, species and electric current in a fully integrated finite-volume solver using the CFD-ACE+ commercial code. The polarization curves of simulation are well correlated with experimental data. Three-dimensional simulations are carried out to treat prediction and analysis of micro PEMFC temperature, current density and water distributions in two different fuel flow rates (15 cm3/min and 40 cm3/min). Simulation results show that temperature distribution within the micro PEMFC is affected by water distribution in the membrane and indicate that low and uniform temperature distribution in the membrane at low fuel flow rates leads to increased membrane water distribution and obtains superior micro PEMFC current density distribution under 0.4V operating voltage. Model predictions are well within those known for experimental mechanism phenomena.

  20. Benchmark thermodynamic properties of methylanisoles: Experimental and theoretical study

    International Nuclear Information System (INIS)

    Emel’yanenko, Vladimir N.; Zaitseva, Ksenia V.; Agapito, Filipe; Martinho Simões, José A.; Verevkin, Sergey P.

    2015-01-01

    Highlights: • Thermochemistry of 2-, 3-, and 4-methylanisoles was studied. • Liquid state enthalpies of formation were measured by calorimetry. • Vaporisation enthalpies were derived from by transpiration method. • Ab initio enthalpies of formation are in excellent agreement with experiment. • A new paradigm for obtaining thermochemistry of liquid compounds was suggested. - Abstract: Accurate standard molar enthalpy of formation values in the liquid phase can be obtained by combining high-level quantum chemistry values of gas-phase enthalpies of formation with experimentally determined enthalpies of vaporisation. The procedure is illustrated for 2-, 3-, and 4-methyl-anisoles. Using the W1-F12 and G4 quantum-chemical methods, the gas-phase enthalpies of formation of these compounds at T = 298.15 K were computed. Molar enthalpies of vaporisation for these isomers were measured by the transpiration method. Combining the experimental and the high-level ab initio values, the standard molar enthalpies of formation in the liquid phase for all three isomers were derived and compared with those determined for 2- and 4-methyl-anisoles by using combustion calorimetry

  1. A comprehensive experimental and modeling study of 2-methylbutanol combustion

    KAUST Repository

    Park, Sungwoo

    2015-05-01

    2-Methylbutanol (2-methyl-1-butanol) is one of several next-generation biofuels that can be used as an alternative fuel or blending component for combustion engines. This paper presents new experimental data for 2-methylbutanol, including ignition delay times in a high-pressure shock tube and premixed laminar flame speeds in a constant volume combustion vessel. Shock tube ignition delay times were measured for 2-methylbutanol/air mixtures at three equivalence ratios, temperatures ranging from 750 to 1250. K, and at nominal pressures near 20 and 40. bar. Laminar flame speed data were obtained using the spherically propagating premixed flame configuration at pressures of 1, 2, and 5. bar. A detailed chemical kinetic model for 2-methylbutanol oxidation was developed including high- and low-temperature chemistry based on previous modeling studies on butanol and pentanol isomers. The proposed model was tested against new and existing experimental data at pressures of 1-40. atm, temperatures of 740-1636. K, equivalence ratios of 0.25-2.0. Reaction path and sensitivity analyses were conducted for identifying key reactions at various combustion conditions, and to obtain better understanding of the combustion characteristics of larger alcohols.

  2. Acting like a physicist: Student approach study to experimental design

    Science.gov (United States)

    Karelina, Anna; Etkina, Eugenia

    2007-12-01

    National studies of science education have unanimously concluded that preparing our students for the demands of the 21st century workplace is one of the major goals. This paper describes a study of student activities in introductory college physics labs, which were designed to help students acquire abilities that are valuable in the workplace. In these labs [called Investigative Science Learning Environment (ISLE) labs], students design their own experiments. Our previous studies have shown that students in these labs acquire scientific abilities such as the ability to design an experiment to solve a problem, the ability to collect and analyze data, the ability to evaluate assumptions and uncertainties, and the ability to communicate. These studies mostly concentrated on analyzing students’ writing, evaluated by specially designed scientific ability rubrics. Recently, we started to study whether the ISLE labs make students not only write like scientists but also engage in discussions and act like scientists while doing the labs. For example, do students plan an experiment, validate assumptions, evaluate results, and revise the experiment if necessary? A brief report of some of our findings that came from monitoring students’ activity during ISLE and nondesign labs was presented in the Physics Education Research Conference Proceedings. We found differences in student behavior and discussions that indicated that ISLE labs do in fact encourage a scientistlike approach to experimental design and promote high-quality discussions. This paper presents a full description of the study.

  3. Acting like a physicist: Student approach study to experimental design

    Directory of Open Access Journals (Sweden)

    Anna Karelina

    2007-10-01

    Full Text Available National studies of science education have unanimously concluded that preparing our students for the demands of the 21st century workplace is one of the major goals. This paper describes a study of student activities in introductory college physics labs, which were designed to help students acquire abilities that are valuable in the workplace. In these labs [called Investigative Science Learning Environment (ISLE labs], students design their own experiments. Our previous studies have shown that students in these labs acquire scientific abilities such as the ability to design an experiment to solve a problem, the ability to collect and analyze data, the ability to evaluate assumptions and uncertainties, and the ability to communicate. These studies mostly concentrated on analyzing students’ writing, evaluated by specially designed scientific ability rubrics. Recently, we started to study whether the ISLE labs make students not only write like scientists but also engage in discussions and act like scientists while doing the labs. For example, do students plan an experiment, validate assumptions, evaluate results, and revise the experiment if necessary? A brief report of some of our findings that came from monitoring students’ activity during ISLE and nondesign labs was presented in the Physics Education Research Conference Proceedings. We found differences in student behavior and discussions that indicated that ISLE labs do in fact encourage a scientistlike approach to experimental design and promote high-quality discussions. This paper presents a full description of the study.

  4. Experimental studies on natural circulation in molten salt loops

    International Nuclear Information System (INIS)

    Srivastava, A.K.; Borgohain, A.; Maheshwari, N.K.; Vijayan, P.K.

    2015-01-01

    Molten salts are increasingly getting attention as a coolant and storage medium in solar thermal power plants and as a liquid fuel, blanket and coolant in Molten Salt Reactors (MSR’s). Two different test facilities named Molten Salt Natural Circulation Loop (MSNCL) and Molten Active Fluoride salt Loop (MAFL) have been setup for thermal hydraulics, instrument development and material related studies relevant to MSR and solar power plants. The working medium for MSNCL is a molten nitrate salt which is a mixture of NaNO 3 and KNO 3 in 60:40 ratio and proposed as one of the coolant option for molten salt based reactor and coolant as well as storage medium for solar thermal power application. On the other hand, the working medium for MAFL is a eutectic mixture of LiF and ThF 4 and proposed as a blanket salt for Indian Molten Salt Breeder Reactor (MSBR). Steady state natural circulation experiments at different power level have been performed in the MSNCL. Transient studies for startup of natural circulation, loss of heat sink, heater trip and step change in heater power have also been carried out in the same. A 1D code LeBENC, developed in-house to simulate the natural circulation characteristics in closed loops, has been validated with the experimental data obtained from MSNCL. Further, LeBENC has been used for Pretest analysis of MAFL. This paper deals with the description of both the loops and experimental studies carried out in MSNCL. Validation of LeBENC along with the pretest analysis of MAFL using the same are also reported in this paper. (author)

  5. Experimental study of parametric instabilities and anomalous heating in plasma

    International Nuclear Information System (INIS)

    Batanov, G.M.; Rabinovich, M.S.

    1975-01-01

    Over the last few years the study of the dissipation of electromagnetic wave energy in a hot plasma has become perhaps one of the main problems of high-temperature plasma physics and controlled thermonuclear fusion. The focus of attention is on the processes by which electromagnetic energy is transformed into potential plasma waves and the processes involving relaxation of the latter. In this paper the authors summarize the experimental research into these processes conducted at the Lebedev Physics Institute over the 10 cm wave band. In the case of an isotropic plasma the authors recorded non-linear generation of Langmuir noise, the energy density of which was found to be comparable, in order of magnitude, with that of a pump wave. They detected the generation of fast-electron streams, the non-stationary character of the latter with respect to time, and non-linear transmissivity of the plasma layer. In the case of a magnetoactive plasma they studied the parametric excitation of oscillations at the upper hybrid frequency during its resonance with the first overtone of the pump wave. Excitation of plasma noise was found to be accompanied by a flux of fast-electrons, in the energy spectrum of which separate groups were detected. It was also found that the effective collision frequency increased by 1-3 orders, compared to the pari-collision frequency. In the region of magnetic waves close to the electron cyclotron resonance the authors observed forced Mandel'shtam-Brillouin scattering and kinetic instability of the plasma. It was found that the excitation of ionic Langmuir noise preceded ''anomalous absorption'' of waves and ''anomalous heating'' of electrons. The authors further consider the possibility of an experimental study of anomalous heating in plasma in the region of the lower hybrid frequencies, using the Institute's L-2 stellarator. (author)

  6. Experimental Studies of Thermal Interactions at AEE Winfrith

    International Nuclear Information System (INIS)

    Briggs, A.J.

    1976-01-01

    Assessment of the consequences of very severe reactor accidents in which fuel is melted involves evaluation of the nature of any thermal interaction between molten fuel or cladding and the reactor coolant. Work on these problems has been pursued in many countries, both experimentally and theoretically, but although much progress has been made there is as yet no well established theoretical description of large scale efficient thermal interactions. The need for further experimental data in this area was one of the main reasons for establishing a new range of experimental facilities at Winfrith which provide the ability to carry out experiments involving explosions under safe conditions. Experiments are set up inside a strong test cell situated in the centre of a 200 m exclusion area. Instrumentation is provided for transient measurements of pressure and strain, and for high speed cine photography. The first part of this programme started early in 1975, and is concerned with the propagation of thermal interaction through a metal/water system. This programme is not yet complete but some results of interest have been obtained. The first part of this paper will describe these experiments and discuss the significance of the results currently available. Such studies of large scale metal/water interactions should help to provide an improved understanding of the way in which propagation might occur in the reactor case, but must be complemented by experiments using reactor materials. The second stage of the Winfrith programme will study the UO 2 /Na system directly. Facilities for the production of pure uranium burning thermite charges will be commissioned early in 1976. This chemical technique for producing molten UO 2 will be used in two main types of experiment. Firstly the interaction of a two phase bubble of UO 2 with a surrounding pool of Na will be studied, extending the investigations of this kind started at AWRE Foulness. Secondly, the heat transfer rate from UO 2

  7. Numerical and Experimental Study of Friction Loss in Hydrostatic Motor

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Mørk; Hansen, Michael R.; Mouritsen, Ole Ø.

    2012-01-01

    This paper presents a numerical and experimental study of the losses in a hydrostatic motor principle. The motor is designed so that the structural de ections and lubricating regimes between moving surfaces and, subsequently, the leakage and friction losses, can be controlled during operation....... This is done by means of additional pressure volumes that in uence the stator de ection. These pressures are referred to as compensation pressures and the main emphasis is on friction or torque loss modeling of the motor as a function of the compensation pressures and the high and low pressures related...... to the load torque. The torque loss modeling is identied as a Stribeck curve which depends on gap height. The asperity friction is decreasing exponentially with an increase in gap height. The parameters of the torque loss model are based on prototype measurements that include the structural de ections...

  8. Simulation and experimental study of resin flow in fibre fabrics

    Science.gov (United States)

    Yan, Fei; Yan, Shilin; Li, Yongjing

    2017-06-01

    Liquid Composite Moulding (LCM) is gradually becoming the most competitive manufacturing technology for producing large composite parts with complex geometry with high quality and low cost. These parts include those for airplanes, wind turbine blades and automobile components. Fibre fabrics in liquid composite moulding can be considered as dual-scale porous media. In different gap scales, an unsaturated flow is produced during the mould filling process. This particular flow behaviour deviates from the traditional Darcy’s law, which is used to calculate the filling pressure and will cause errors. According to sink theory, the unsaturated flow characteristics of this dual-scale porous media were studied in this paper, and a FEM solution program was developed. The results showed that the pressure curves against the position which simulated by sink functions were departure from the position of traditional theory. In addition, the simulation results of partially-saturated region were consistent with the experimental data.

  9. A theoretical-experimental study of backup bearings

    DEFF Research Database (Denmark)

    Lampe Linhares da Fonseca, Cesar Augusto

    of two types of backup bearings, which are investigated experimentally and theoretically. The first type is a conventional ball bearing commonly used in industrial applications. The second is an unconventional bearing that, which contains pins inside the clearance for the rotor to impact on. The main...... both types of bearings for further investigation. Also, a full failure of the control and a rotor drop on the ball bearing as backup bearing is investigated by removing the magnetic forces. The nonlinear features of the dynamics of the rotor are assessed for different levels of unbalance. It has been...... radial forces. Remaining in this condition, it may lead to permanent damage or total failure of the machine. This is why the backup bearing design has to be carefully planned and investigated as to whether it helps to protect the integrity of the machine. This PhD thesis provides a comprehensive study...

  10. Experimental studies of glued Aluminum-glass joints

    Science.gov (United States)

    Ligaj, B.; Wirwicki, M.; Karolewska, K.; Jasińska, A.

    2018-04-01

    Glued steel-glass or aluminum-glass joints are to be found, among other things, in vehicles (cars, buses, trains, trams) as windscreen assembly pieces for the supporting structure. For the purposes of the experiments, samples were made in which the top beam was made of the AW-2017A aluminum alloy and the bottom beam was made of thermally reinforced soda-lime glass whereas the glued joints were made of one-component polyurethane glue Körapur 175. The tests were performed under four-point bending conditions at monotonic incremental bending moment values on the Instron 5965 durability machine. The experimental study of the durability of glued joints under four-point bending conditions with the monotonic incremental bending moment allows to determine the values of stresses, whose value is related to initiation of damage of the tested joint.

  11. Experimental studies of an Extrap Z-Pinch

    International Nuclear Information System (INIS)

    Drake, J.R.

    1983-01-01

    Experimental studies of the formation, equilibrium and stability of a linear Extrap Z-pinch are reported on. The Z-pinch discharge is generated between electrodes along the Z-axis of a linear octupole field produced by currents in four Z-directed rods. The combined discharge current and rod currents produce a magnetic field having a separatrix with four null X-points which define the corners of a square shaped region where the high beta plasma discharge is contained. Bounding the pinch discharge with a separatrix produces equilibria which are stable against global kink modes for the 50-μsec duration of the discharge which corresponds to about 100 Alfven transit times. The equilibria, with line densities of about 3 x 10 18 m - 1 , are consistent in magnitude and scaling with the Bennet relation. (Author)

  12. An experimental facility for studying delayed neutron emission

    International Nuclear Information System (INIS)

    Dermendzhiev, E.; Nazarov, V.M.; Pavlov, S.S.; Ruskov, Iv.; Zamyatin, Yu.S.

    1993-01-01

    A new experimental facility for studying delayed neutron emission has been designed and tested. A method based on utilization of the Dubna IBR-2 pulsed reactor, has been proposed and realized for periodical irradiation of targets composed of fissionable isotopes. Such a powerful pulsed neutron source in combination with a slow neutron chopper synchronized with the reactor bursts makes possible variation of the exposure duration and effective suppression of the fast neutron background due to delay neutrons emitted from the reactor core. Detection of delayed neutrons from the target is carried out by a high-efficiency multicounter neutron detector with a near-4π geometry. Some test measurements and results are briefly described. Possible use of the facility for other tasks is also discussed. 14 refs.; 14 figs

  13. Experimental studies on the heavy quark fragmentation functions

    International Nuclear Information System (INIS)

    Bethke, S.

    1985-07-01

    The influence of perturbative QCD gluon radiation and initial state photon radiation on the experimental determination of the heavy quark fragmentation functions is studied in order to extract , the mean of the charm fragmentation function, from the recent measurements of inclusive Dsup(*) production in e + e - annihilation processes. The result is =0.71+-0.014+-0.03, which is scale invariant in the c.m. energy range of 10 GeV to 34 GeV. This result is interpreted in terms of kinematical calculations on heavy quark fragmentation and also compared with results from ν-N-reactions and from investigations of inclusive lepton production in e + e - annihilation. Results of a QCD shower model are in good agreement with the data and offer an alternative description of phenomenological fragmentation functions. (orig.)

  14. An experimental study on improvement of Savonius rotor performance

    Directory of Open Access Journals (Sweden)

    N.H. Mahmoud

    2012-03-01

    In this work different geometries of Savonius wind turbine are experimentally studied in order to determine the most effective operation parameters. It was found that, the two blades rotor is more efficient than three and four ones. The rotor with end plates gives higher efficiency than those of without end plates. Double stage rotors have higher performance compared to single stage rotors. The rotors without overlap ratio (β are better in operation than those with overlap. The results show also that the power coefficient increases with rising the aspect ratio (α. The conclusions from the measurements of the static torque for each rotor at different wind speeds verify the above summarized results of this work.

  15. Experimental study of the pressure characteristics in the Stirling refrigerator

    International Nuclear Information System (INIS)

    Hong, Yong Ju; Park, Seong Je; Kim, Hyo Bong; Koh, Deuk Yong

    2001-01-01

    The linear compressor have been widely used for pressure wave generation in the Stirling cryocooler and Stirling type pulse tube cryocooler for tactical purpose. The linear compressor has small and compact structure, and long life due to having non-contact sealing mechanism and the pressure drop through regenerator was ver important role in the motion of displacer in the expander of the Stirling cryocooler. In this study, the characteristic of the linear compressor and the pressure drop through regenerator in the expander was experimentally investigated. The results show resonance of the compressor is very important to get maximum performance and the gas spring force in the compression space of the compressor has effect on the characteristic of resonance and the results show the pressure drop through regenerator is very small than operating pressure change

  16. EXPERIMENTAL STUDY ON SEDIMENT DISTRIBUTION AT CHANNEL BIFURCATION

    Institute of Scientific and Technical Information of China (English)

    G.M. Tarekul ISLAM; M.R. KABIR; Ainun NISHAT

    2002-01-01

    This paper presents the experimental results on the distribution of sediments at channel bifurcation.The experiments have been conducted in a physical model of channel bifurcation. It consists of a straight main channel which bifurcates into two branch channels of different widths. The test rig is a mobile bed with fixed bank. Four different noses have been used to study the phenomenon. For each nose, three upstream discharges viz. 20 l/s, 30 l/s and 40 l/s have been employed. From the measured data, discharges and sediment transport ratios per unit width are calculated in the downstream branches.These data have been set to the general nodal point relation and a set of equations has been developed to describe the distribution of sediments to the downstream branches for different nose angles.

  17. Numerical and Experimental Study of Pump Sump Flows

    Directory of Open Access Journals (Sweden)

    Wei-Liang Chuang

    2014-01-01

    Full Text Available The present study analyzes pump sump flows with various discharges and gate submergence. Investigations using a three-dimensional large eddy simulation model and an acoustic Doppler velocimeter are performed. Flow patterns and velocity profiles in the approaching flow are shown to describe the flow features caused by various discharges and gate submergence. The variation of a large-scale spanwise vortex behind a sluice gate is examined and discussed. The suction effect on approaching flow near the pipe column is examined using numerical modeling. To gain more understanding of the vortices variation, a comparison between time-averaged and instantaneous flow patterns is numerically conducted. Additionally, swirl angle, a widely used index for evaluating pump efficiency, is experimentally and numerically examined under various flow conditions. The results indicate that the pump becomes less efficient with increasing discharge and gate submergence. The fluctuation of the free surface over the pump sump is also discussed.

  18. Experimental study on birefringence effect in high-tension bolts

    International Nuclear Information System (INIS)

    Kim, No You; Lee, Sang Soon; Jang, Kyung Young

    2005-01-01

    Bolts widely used in machine parts and assemblies are pre-loaded to prevent the parts from separating and to maintain the strength of the assemblies. Conventional technique for measurement of this axial stress applied to bolts is torque meter, but it has two disadvantages. The first one is its inherent inaccuracy. The second is that the stress cannot be determined after assembly without twisting bolts. The most promising technique for measurement of the axial stress is the acousto-elasticity. In this study, a new acousto-elasticity technique based on birefringence principle is proposed and tested to measure the axial stress in bolts which uses two longitudinal and shear waves instead of two horizontally polarized shear waves. From experimental results, the difference between the longitudinal and shear wave velocity is shown to be linearly related to the applied stress and be able to be used effectively to monitor the axial stress in bolts.

  19. Laser-welded ureteral anastomoses: experimental studies with three techniques.

    Science.gov (United States)

    Gürpinar, T; Gürer, S; Kattan, M W; Wang, L; Griffith, D P

    1996-01-01

    Tissue welding with laser energy is a new technique for reconstructive surgery. The potential advantages of laser welding are (a) lack of foreign body reaction, (b) decreased operative time, (c) less tissue manipulation, and (d) effective union of tissues equivalent to sutured anastomoses. We have performed ureteral anastomoses in adult mongrel dogs using a KTP 532 nm laser at an intensity of 1.4 W. Multiple "spot welds" of 1-s duration were utilized in a single layer anastomosis. Laser-welded anastomoses were performed with and without protein solder (33% and 50% human albumin) and were compared to sutured anastomoses. The laser-welded anastomoses required less operative time and provided bursting pressure levels similar to those of traditional sutured anastomoses. There was no advantage or disadvantage to the addition of human albumin as a solder in these experimental studies.

  20. An experimental study on the normal stress of magnetorheological fluids

    International Nuclear Information System (INIS)

    Jiang, Jile; Tian, Yu; Ren, Dongxue; Meng, Yonggang

    2011-01-01

    The dependence of the normal stress on the shear rate and magnetic field strength in the shear flow of magnetorheological (MR) fluids has been studied experimentally. An obvious normal stress could be observed when the applied magnetic field was higher than a critical value. The normal stress increases considerably with increase of the shear rate and magnetic field, and decreases suddenly and significantly upon the onset of shear thickening in MR fluids. The ratio of shear stress to normal stress, an analogue of the friction coefficient, increases with increase of the shear rate, but decreases with increase of the applied magnetic field. Along with the shear stress, the normal stress in MR fluids could provide a more comprehensive understanding of the MR effect, and the evolution of the particle structure in shear flow, and may have important implications for preparing high performance magnetostrictive elastomers with high force output along the magnetic field direction

  1. Development and preliminary experimental study on micro-stacked insulator

    International Nuclear Information System (INIS)

    Ren Chengyan; Yuan Weiqun; Zhang Dongdong; Yan Ping; Wang Jue

    2009-01-01

    High gradient insulating technology is one of the key technologies in new type dielectric wall accelerator(DWA). High gradient insulator, namely micro-stacked insulator, was developed and preliminary experimental study was done. Based on the finite element and particle simulating method, surface electric field distribution and electron movement track of micro-stacked insulator were numerated, and then the optimized design proposal was put forward. Using high temperature laminated method, we developed micro-stacked insulator samples which uses exhaustive fluorinated ethylene propylene(FEP) as dielectric layer and stainless steel as metal layer. Preliminary experiment of vacuum surface flashover in nanosecond pulse voltage was done and micro-stacked insulator exhibited favorable vacuum surface flashover performance with flashover field strength of near 180 kV/cm. (authors)

  2. An experimental study of the fabrication of polycarbonate optical waveguides

    Science.gov (United States)

    Chen, Jianguo; Zhang, Xiao-yang; Zhang, Tong; Zhu, Jing-song; Wu, Peng-qin; Zhou, Jing-lun; Fan, Jiang-feng; Yan, Hao-feng

    2008-12-01

    A novel polycarbonate (PC) was introduced to apply in the optical waveguide devices. PC has following distinct merits than common polycarbonate: good processability, high thermal stability up to 293 C° and high optical transparency. Optical properties of absorption behavior and propagation loss were investigated in slab waveguides, and low propagation losses of 0.335 dB/cm (@1550nm) and 0.197 dB/cm @632.8nm) have been achieved by using prismcoupler. Additionally, straight optical waveguide and MMI coupler of ring resonator were fabricated using ultraviolet (UV) cured resin Norland optical adhesive 61 (NOA61) as under or upper cladding layer and polycarbonate as waveguide core-layer material through conventional methods such as spin coating, photolithography and reactive ion etching (RIE). The process was studied in detail and the experimental results were given.

  3. Experimental studies of pion-nucleus interactions at intermediate energies

    International Nuclear Information System (INIS)

    1992-01-01

    This report summarizes investigations of various pion-nucleus interactions and nucleon-nucleus charge-exchange reactions. The work was carried out with the LAMPF accelerator at the Los Alamos National Laboratory and the cyclotrons at the Paul Scherrer Institute (PSI) near Zurich, Switzerland, and at Indiana University (IUCF), as a collaborative effort among several laboratories and universities. The experimental activity at LAMPF involved measurements of new data on pion double-charge-exchange scattering, some initial work on a new Neutral Meson Spectrometer system, a search for deeply-bound pionic atoms, measurements of elastic scattering, and studies of the (n,p) reaction on various nuclei. At PSI measurements of pion quasielastic scattering were carried out, with detection of the recoil proton. Work on the analysis of data from a previous experiment at PSI on pion absorption in nuclei was continued. This experiment involved using a detector system that covered nearly the full solid angle

  4. Experimental studies of radioactive new formations of object 'Shelter'

    International Nuclear Information System (INIS)

    Vishnevskij, A.S.; Kuz'mina, I.E.; Tkach, V.N.; Tokarevskij, V.V.

    1996-01-01

    Chemical and phase composition of radioactive new-formations of object 'Shelter ' have been experimentally studied by the X-ray and local electronic probe methods of the substance analysis. Leaching of uranium is shown to be a result of attack by alkali-carbonate solutions, migration of uranium take place in the form of double alkali-carbonate system Na 4 [U O 2 (CO 3 ) 3 ]. Carbonates, sulphates, halite and probably sulphates-carbonates were found in the mineral association of new-formations. A hypothesis of formation of sodium uranyltetracarbonate Na 6 (U O 2 )(CO 3 ) 4 , under conditions of object 'Shelter' which was not described in scientific literature before has been advanced

  5. Experimental studies of PWR primary piping under loca

    International Nuclear Information System (INIS)

    Caumette, Pierre; Garcia, J.L.

    1980-07-01

    The experimental program performed on AQUITAINE II facility is directed to study the mechanical behavior of primary PWR pipes and the forces exerted on the neighbouring structures as a consequence of a breach opening. It has been developed in the form of a quadripartite agreement between the Commissariat a l'Energie Atomique, Framatome, Electricite de France and Westinghouse. Some forty tests have been carried out with different pipe configurations (straight tube, elbow, S- or U-shaped tube) and different break types (single or double guillotine). The following aspects are investigated: - the dynamic behavior of the pipe and in particular the formation of a plastic hinge at the restraint; - the impact function of a pipe or an energy-absorbing bumper; - the lateral stability of both ends of a pipe, after a double-guillotine break [fr

  6. An experimental and modeling study of n-octanol combustion

    KAUST Repository

    Cai, Liming

    2015-01-01

    This study presents the first investigation on the combustion chemistry of n-octanol, a long chain alcohol. Ignition delay times were determined experimentally in a high-pressure shock tube, and stable species concentration profiles were obtained in a jet stirred reactor for a range of initial conditions. A detailed kinetic model was developed to describe the oxidation of n-octanol at both low and high temperatures, and the model shows good agreement with the present dataset. The fuel\\'s combustion characteristics are compared to those of n-alkanes and to short chain alcohols to illustrate the effects of the hydroxyl moiety and the carbon chain length on important combustion properties. Finally, the results are discussed in detail. © 2014 The Combustion Institute.

  7. Experimental studies of thermal preparation of internal combustion engine

    Science.gov (United States)

    Karnaukhov, N. N.; Merdanov, Sh M.; V, Konev V.; Borodin, D. M.

    2018-05-01

    In conditions of autonomous functioning of road construction machines, it becomes necessary to use its internal sources. This can be done by using a heat recovery system of an internal combustion engine (ICE). For this purpose, it is proposed to use heat accumulators that accumulate heat of the internal combustion engine during the operation of the machine. Experimental studies have been carried out to evaluate the efficiency of using the proposed pre-start thermal preparation system, which combines a regular system based on liquid diesel fuel heaters and an ICE heat recovery system. As a result, the stages of operation of the preheating thermal preparation system, mathematical models and the dependence of the temperature change of the antifreeze at the exit from the internal combustion engine on the warm-up time are determined.

  8. Perceptions of unfairness in price increases: an experimental study

    Directory of Open Access Journals (Sweden)

    Verônica Feder Mayer

    2014-09-01

    Full Text Available This experimental study investigates antecedents and consequences of perceptions of price unfairness in a price increase situation. The proposed theoretical model states that consumer dependence on the service provider as well as the relevance the consumer attributes to the service (for the consumer's life will affect his/her degree of (a unfairness price perception, (b anger, and (c intention to complain and retaliate. The results support all the hypotheses specified in the model. The findings not only indicate that some situations of unfairness price perception lead to stronger emotions and more dramatic reactions from consumers, but also allow us to predict which situations of perceived unfairness offer greater risks and have greater potential for conflict.

  9. Experimental study of plastic responses of pipe elbows

    International Nuclear Information System (INIS)

    Greenstreet, W.L.

    1978-01-01

    Load-deflection responses were determined experimentally for sixteen 152.4-mm (6-in.) (nominal) commercial carbon steel pipe elbows and four 152.4-mm (6-in.) stainless steel elbows. Each specimen was loaded with an external force of sufficient magnitude to produce predominantly plastic response. The influences of bend radius and wall thickness were studied, as well as the effect of internal prssure on load-deflection behavior. Comparisons of results from stainless steel and from carbon steel elbows indicate differences in responses attributable to material differences. The results were interpreted in terms of limit analysis concepts, and collapse loads were determined. Trends given by the collapse loads are identified and discussed

  10. Experimental and theoretical studies of buoyant-thermo capillary flow

    International Nuclear Information System (INIS)

    Favre, E.; Blumenfeld, L.; Soubbaramayer

    1996-01-01

    In the AVLIS process, uranium metal is evaporated using a high power electron gun. We have prior discussed the power balance equation in the electron beam evaporation process and pointed out, among the loss terms, the importance of the power loss due to the convective flow in the molten pool driven by buoyancy and thermo capillarity. An empirical formula has been derived from model experiments with cerium, to estimate the latter power loss and that formula can be used practically in engineering calculations. In order to complete the empirical approach, a more fundamental research program of theoretical and experimental studies have been carried out in Cea-France, with the objective of understanding the basic phenomena (heat transport, flow instabilities, turbulence, etc.) occurring in a convective flow in a liquid layer locally heated on its free surface

  11. Experimental study on fundamental performance of reverse flow diverters

    International Nuclear Information System (INIS)

    Fan Yanfang; Xu Cong; Jing Shan

    2008-01-01

    The Reverse Flow Diverter (RFD) is one of the key components affecting the liquid-delivered efficiency. The effects of inflow structure, outflow structure, area ratio and suction gap on the performance of RFDs were studied in this paper. It can be found experimentally that expected entrainment phenomenon can be achieved when the outlet velocity of fluid for RFDs' inflow structure is sufficient. There is less liquid delivered by an RFD with a long receiver than that without a receiver. Because of back-flow caused by vortex separation, oversize area ratio cannot have better entrainment phenomenon and the optimum area ratio is 1.5. When the ratio of suction gap length to inlet diameter of outflow structure is 0.9-1.0, the excellent liquid-delivered efficiency can be obtained. (authors)

  12. ITER [International Thermonuclear Experimental Reactor] reactor building design study

    International Nuclear Information System (INIS)

    Thomson, S.L.; Blevins, J.D.; Delisle, M.W.

    1989-01-01

    The International Thermonuclear Experimental Reactor (ITER) is at the midpoint of a two-year conceptual design. The ITER reactor building is a reinforced concrete structure that houses the tokamak and associated equipment and systems and forms a barrier between the tokamak and the external environment. It provides radiation shielding and controls the release of radioactive materials to the environment during both routine operations and accidents. The building protects the tokamak from external events, such as earthquakes or aircraft strikes. The reactor building requirements have been developed from the component designs and the preliminary safety analysis. The equipment requirements, tritium confinement, and biological shielding have been studied. The building design in progress requires continuous iteraction with the component and system designs and with the safety analysis. 8 figs

  13. Experimental study of drag reduction in flumes and spillway tunnels

    Directory of Open Access Journals (Sweden)

    Ying-kui Wang

    2010-06-01

    Full Text Available Experiments in an open flume model and spillway tunnel model were carried out using drag reduction techniques. Two drag reduction techniques were adopted in the experiments: polymer addition and coating. The drag reduction effect of a polyacrylamide (PAM solution and dimethyl silicone oil coating were studied in the flume model experiments, and the results were analyzed. Experiments were then carried out with a model of the Xiluodu Hydropower Station, the second largest dam in China. In order to reduce the resistance, the spillway tunnels were internally coated with dimethyl silicone oil. This is the first time that these drag reduction techniques have been applied to so large a hydraulic model. The experimental results show that the coating technique can effectively increase flood discharge. The outlet velocity and the jet trajectory distance are also increased, which enhances the energy dissipation of the spillway tunnel.

  14. Experimental study of micro-shock tube flow

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Ouk; Kim, Gyu Wan; Rasel, Md. Alim Iftakhar [Dept. of Mechanical Engineering, Andong National University, Andong (Korea, Republic of); Kim, Heuy Dong [Fire Research Center, Korea Institute of Civil Engineering and Building Technology, Hwasung (Korea, Republic of)

    2015-03-15

    The flow characteristics in micro shock tube are investigated experimentally. Studies were carried out using a stainless steel micro shock tube. Shock and expansion wave was measured using 8 pressure sensors. The initial pressure ratio was varied from 4.3 to 30.5, and the diameter of tube was also changed from 3 mm to 6 mm. Diaphragm conditions were varied using two types of diaphragms. The results obtained show that the shock strength in the tube becomes stronger for an increase in the initial pressure ratio and diameter of tube. For the thinner diaphragm, the highest shock strength was found among varied diaphragm condition. Shock attenuation was highly influenced by the diameter of tube.

  15. Arterial scleroproteins in atherosclerosis and hypertension (Experimental studies)

    International Nuclear Information System (INIS)

    Yurukova, Ts.; Georgiev, P.

    1979-01-01

    The authors studied the neosynthesis of fiber protein (scleroproteins) in the aorta of rats with genetic hypertension and with experimental atherosclerosis following application of 3 H-proline and 3 H-lysine and subsequent determination of radioactivity of the collagen and elastic fractions of the aortic wall. There was a great increase in incorporation of labelled collagen and elastin precursors in the aorta of hypertensive and atherosclerotic animals, in comparison with the control rats - a manifestation of incresed ''de novo'' synthesis of fiber proteins in rats with these arterial diseases. Furthermore, the increased collagenosis dominated over that of elastogenesis. The irregular activation of the biosynthesis of both scleroproteins in hypertensive rats and in rats with atherosclerosis caused remodelling of the macromolecular structure of the arterial wall with predominance of collagen over the remaining hypertension components and progression of atherosclerosis. (author) (author)

  16. Tritium system design studies of fusion experimental breeder

    International Nuclear Information System (INIS)

    Deng Baiquan; Huang Jinhua

    2003-01-01

    A summary of the tritium system design studies for the engineering outline design of a fusion experimental breeder (FEB-E) is presented. This paper is divided into three sections. In first section, the geometry, loading features and tritium concentrations in liquid lithium of tritium breeding zones of blanket are described. The tritium flow chart corresponding to the tritium fuel cycle system has been constructed, and the inventories in ten subsystems are calculated using SWITRIM code in section 2. Results show that the necessary initial tritium storage to start up FEB-E with fusion power of 143 MW is about 319 g. In final section, the tritium leakage issues under different operation circumstances have been analyzed. It was found that the potential danger of tritium leakage could be resulted from the exhausted gas of the diverter system. It is important to elevate the tritium burnup fraction and reduce the tritium throughput. (authors)

  17. Experimental study of filter cake formation on different filter media

    International Nuclear Information System (INIS)

    Saleem, M.

    2009-01-01

    Removal of particulate matter from gases generated in the process industry is important for product recovery as well as emission control. Dynamics of filtration plant depend on operating conditions. The models, that predict filter plant behaviour, involve empirical resistance parameters which are usually derived from limited experimental data and are characteristics of the filter media and filter cake (dust deposited on filter medium). Filter cake characteristics are affected by the nature of filter media, process parameters and mode of filter regeneration. Removal of dust particles from air is studied in a pilot scale jet pulsed bag filter facility resembling closely to the industrial filters. Limestone dust and ambient air are used in this study with two widely different filter media. All important parameters like pressure drop, gas flow rate, dust settling, are recorded continuously at 1s interval. The data is processed for estimation of the resistance parameters. The pressure drop rise on test filter media is compared. Results reveal that the surface of filter media has an influence on pressure drop rise (concave pressure drop rise). Similar effect is produced by partially jet pulsed filter surface. Filter behaviour is also simulated using estimated parameters and a simplified model and compared with the experimental results. Distribution of cake area load is therefore an important aspect of jet pulse cleaned bag filter modeling. Mean specific cake resistance remains nearly constant on thoroughly jet pulse cleaned membrane coated filter bags. However, the trend can not be confirmed without independent cake height and density measurements. Thus the results reveal the importance of independent measurements of cake resistance. (author)

  18. Quasi-experimental study designs series-paper 8: identifying quasi-experimental studies to inform systematic reviews.

    Science.gov (United States)

    Glanville, Julie; Eyers, John; Jones, Andrew M; Shemilt, Ian; Wang, Grace; Johansen, Marit; Fiander, Michelle; Rothstein, Hannah

    2017-09-01

    This article reviews the available evidence and guidance on methods to identify reports of quasi-experimental (QE) studies to inform systematic reviews of health care, public health, international development, education, crime and justice, and social welfare. Research, guidance, and examples of search strategies were identified by searching a range of databases, key guidance documents, selected reviews, conference proceedings, and personal communication. Current practice and research evidence were summarized. Four thousand nine hundred twenty-four records were retrieved by database searches, and additional documents were obtained by other searches. QE studies are challenging to identify efficiently because they have no standardized nomenclature and may be indexed in various ways. Reliable search filters are not available. There is a lack of specific resources devoted to collecting QE studies and little evidence on where best to search. Searches to identify QE studies should search a range of resources and, until indexing improves, use strategies that focus on the topic rather than the study design. Better definitions, better indexing in databases, prospective registers, and reporting guidance are required to improve the retrieval of QE studies and promote systematic reviews of what works based on the evidence from such studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Experimental and analytical study on thermoelectric self cooling of devices

    International Nuclear Information System (INIS)

    Martinez, A.; Astrain, D.; Rodriguez, A.

    2011-01-01

    This paper presents and studies the novel concept of thermoelectric self cooling, which can be introduced as the cooling and temperature control of a device using thermoelectric technology without electricity consumption. For this study, it is designed a device endowed with an internal heat source. Subsequently, a commonly used cooling system is attached to the device and the thermal performance is statistically assessed. Afterwards, it is developed and studied a thermoelectric self cooling system appropriate for the device. Experimental and analytical results show that the thermal resistance between the heat source and the environment reduced by 25-30% when the thermoelectric self cooling system is installed, and indicates the promising applicability of this technology to devices that generate large amounts of heat, such as electrical power converters, transformers and control systems. Likewise, it was statistically proved that the thermoelectric self cooling system leads to significant reductions in the temperature difference between the heat source and the environment, and, what is more, this reduction increases as the heat flow generated by the heat source increases, which makes evident the fact that thermoelectric self cooling systems work as temperature controllers. -- Highlights: → Novel concept of thermoelectric self cooling is presented and studied. → No extra electricity is needed. → Thermal resistance between the heat source and the environment reduces by 25-30%. → Increasing reduction in temperature difference between heat source and environment. → Great applicability to any device that generates heat and must be cooled.

  20. Entrepreneurship Education: An Experimental Study with Information and Communication Technology

    Directory of Open Access Journals (Sweden)

    Yenchun Jim Wu

    2018-03-01

    Full Text Available Entrepreneurship has been regarded as a new science in the promotion of economic development, which has led to rapid development in entrepreneurship education. The growing number of students enrolled in entrepreneurship programs creates unprecedented challenges on educators. Although multiple teaching and learning activities are adopted in entrepreneurship education, these are mainly carried out using traditional classroom lectures, case studies and group discussions. Nowadays, information & communication technology (ICT is used to enhance the effectiveness of traditional teaching methods and competency training. PowToon is a web-based ICT tool that hat allows teachers and students to quickly and easily create animated presentations. Using quasi-experimental design and qualitative method, this study is to examine whether PowToon is an effective tool for business plan presentation. The study find that the animated presentations attracted more investment than the groups that did not prepare animated videos. It reflects that developed videos which helps entrepreneurial team to better deliver their business ideas to investors in a well-thought out way. In addition, the results of the study show that individuals who generate a business idea did not necessarily significantly influence their investment decisions. Our findings challenge the concept on self-biases evaluations of the economic potential of their own business ideas. Finally, the students were very willing to adopt new ways of delivering their business ideas.

  1. Conceptual design study of fusion experimental reactor (FY86 FER)

    International Nuclear Information System (INIS)

    Nakashima, Kunihiko; Okano, Kunihiko; Miyamoto, Kazuhiro.

    1987-09-01

    This report describes the results of a conceptual study on the RF system in the typical candidates for the Fusion Experimental Reactor (FER), which were picked out through the '86FER scoping studies. According to the FER operation scenario, three RF systems, that is, ICRF (heating), LHRF (current drive and heating), ECRF (auxiliary heating) were studied. Main concern in these RF systems is the launcher, which may be so designed that required power match the geometrical constraints of the reactor. Then studies were concentrated on the launcher configuration. A prug-in concept of the launcher was adopted in each system and vacancies except transmission space were filled with water. The ICRF launcher had the 2 x 2 loop arrays antenna and the faraday shield area of 1.5 m x 1 m to provide a power of 20 MW. The LHRF launcher had the grillantenna with 28 x 8 open waveguides, and included multi junction-type power splitters which were connected to 56 transmission wave guides. The grild was designed to have two functions of current drive and heating, and provide a power of 20 MW each. The ECRF launcher had a boundle of open wave guides which a reflection mirror each, and three plain mirrors. Assuming a oscillator unit size of 200 kW, it had 40 oversized wave guides to provide a power of 3 MW. (author)

  2. Physics design and experimental study of tokamak divertor

    International Nuclear Information System (INIS)

    Yan Jiancheng; Gao Qingdi; Yan Longwen; Wang Mingxu; Deng Baiquan; Zhang Fu; Zhang Nianman; Ran Hong; Cheng Fayin; Tang Yiwu; Chen Xiaoping

    2007-06-01

    The divertor configuration of HL-2A tokamak is optimized, and the plasma performance in divertor is simulated with B2-code. The effects of collisionality on plasma-wall transition in the scrape-off layer of divertor are investigated, high performances of the divertor plasma in HL-2A are simulated, and a quasi- stationary RS operation mode is established with the plasma controlled by LHCD and NBI. HL-2A tokamak has been successfully operated in divertor configuration. The major parameters: plasma current I p =320 kA, toroidal field B t =2.2 T, plasma discharger duration T d =1580 ms ware achieved at the end of 2004. The preliminary experimental researches of advanced diverter have been carried out. Design studies of divertor target plate for high power density fusion reactor have been carried out, especially, the physical processes on the surface of flowing liquid lithium target plate. The exploration research of improving divertor ash removal efficiency and reducing tritium inventory resulting from applying the RF ponderomotive force potential is studied. The optimization structure design studies of FEB-E reactor divertor are performed. High flux thermal shock experiments were carried on tungsten and carbon based materials. Hot Isostatic Press (HIP) method was employed to bond tungsten to copper alloys. Electron beam simulated thermal fatigue tests were also carried out to W/Cu bondings. Thermal desorption and surface modification of He + implanted into tungsten have been studied. (authors)

  3. Experimental Studies of Light Emission Phenomena in Superconducting RF Cavitites

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, P.L.; /SLAC; Delayen, J.R.; /Jefferson Lab; Fryberger, D.; /SLAC; Goree, W.S.; Mammosser, J.; /Jefferson Lab /SNS Project, Oak Ridge; Szalata, Z.M.; II, J.G.Weisend /SLAC

    2009-08-04

    Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from {approx} 1/2 to {approx} 2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects {le} 1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most perplexing aspect of this new mode was the observation of as many as seven luminous objects arrayed in what might be described as a macromolecular formation, coherently moving about in the interior of the cavity for extended periods of time, evidently without any wall contact. It is suggested that these mobile luminous objects are without explanation within the realm of established physics. Some remarks about more exotic theoretical possibilities are made, and future plans are discussed.

  4. Experimental study of vortex breakdown in a cylindrical, swirling flow

    Science.gov (United States)

    Stevens, J. L.; Celik, Z. Z.; Cantwell, B. J.; Lopez, J. M.

    1996-01-01

    The stability of a steady, vortical flow in a cylindrical container with one rotating endwall has been experimentally examined to gain insight into the process of vortex breakdowwn. The dynamics of the flow are governed by the Reynolds number (Re) and the aspect ratio of the cylinder. Re is given by Omega R(sup 2)/nu, where Omega is the speed of rotation of the endwall, R is the cylinder radius, and nu is the kinematic viscosity of the fluid filling the cylinder. The aspect ratio is H/R, where H is the height of the cylinder. Numerical simulation studies disagree whether or not the steady breakdown is stable beyond a critical Reynolds number, Re(sub c). Previous experimental researches have considered the steady and unsteady flows near Re(sub c), but have not explored the stability of the steady breakdown structures beyond this value. In this investigation, laser induced fluorescence was utilized to observe both steady and unsteady vortex breakdown at a fixed H/R of 2.5 with Re varying around Re(sub c). When the Re of a steady flow was slowly increased beyond Re(sub c), the breakdown structure remained steady even though unsteadiness was possible. In addition, a number of hysteresis events involving the oscillation periods of the unsteady flow were noted. The results show that both steady and unsteady vortex breakdown occur for a limited range of Re above Re(sub c). Also, with increasing Re, complex flow transformations take place that alter the period at which the unsteady flow oscillates.

  5. Experimental study on combination of chemotherapy and radiotherapy

    International Nuclear Information System (INIS)

    Tanaka, Juichi

    1986-01-01

    Recently, by applying multidrug therapy using cisplatin and bleomycin to the treatment of head and neck cancer, the response rate of chemotherapy has been markedly increased and thus, chemotherapy has taken an important part in the treatment of head and neck cancer. In this paper a clinical application of chemotherapy in combination with radiotherapy was evaluated from the point of the cure rate and also preservation of the structures and the functions of the head and neck region. In order to test the advantage or usefulness of initial chemotherapy followed by radiotherapy (= pre-radiation chemotherapy), the experimental study on combination of chemotherapy and radiotherapy was designed by using ICR mice and Ehrlich solid carcinoma. Cisplatin and peplomycin, a newly developed derivative of bleomycin, were used as chemotherapeutic agents. Tumor growth delay rate was chosen as a parameter to indicate the effectiveness. Results obtained are as follows. 1. Combination chemotherapy of cisplatin and peplomycin was more effective than each single agent on Ehrlich solid carcinoma. Synergistic effect was obtained by higher dose. So, the combination of cisplatin and peplomycin was proved to be eligible for pre-radiation chemotherapy. 2. Synergistic effect of chemotherapy and radiotherapy was observed when chemotherapy was used prior to radiotherapy on Ehrlich solid carcinoma. 3. Even their additional effect was not recognized when radiotherapy preceded to chemotherapy on Ehrlich solid carcinoma. 4. No severe toxic effect was seen in the mice. The experimental results made it clear that pre-radiation chemotherapy is beneficial to the treatment of head and neck cancer. (author)

  6. Experimental and theoretical studies of manganite and magnetite compounds

    International Nuclear Information System (INIS)

    Srinitiwarawong, Chatchai

    2002-01-01

    In the recent years interest in the transition oxide compounds has renewed among researchers in the field of condensed matter physics. This thesis presents the studies of the two families of the transition oxides, the manganite and magnetite compounds. Manganite has regained the interest since the discovery of the large magnetoresistance around its Curie temperature in 1990s. Magnetite on the other hand is the oldest magnetic material known to man however some of its physical properties are still controversial. The experimental works address some basic properties of these compounds when fabricated in the form of thin films. These include the resistivity measurements and magnetic measurements as well as the Hall effect. The various models of transport mechanism have been compared. The magnetic field and the temperature dependence of magnetoresistance have also been studied. Simple devices such as an artificial grain boundary and bilayers thin film have been investigated. The second part of this thesis concentrates on the theoretical aspects of the fundamental physics behind these two compounds. The problem of electrons tunnelling between the magnetite electrodes has been addressed taking into account the surface effect with distortion. The last chapter presents a theoretical study of the spinless-Hubbard model which is the simplest approximation of the conduction electrons in magnetite and manganite. The results are obtained from the Hartree-Fock and the Hubbard-I approximations as well as the exact diagonalisation method. (author)

  7. Experimental study on intermediate level radioactive waste processing

    International Nuclear Information System (INIS)

    Nagakura, Tadashi; Abe, Hirotoshi; Okazawa, Takao; Hattori, Seiichi; Maki, Yasuro

    1977-01-01

    In the disposal of intermediate level radioactive wastes, multilayer package will be adopted. The multilayer package consists of cement-solidified waste and a container such as a drum - can with concrete liner or a concrete container. So, on the waste to be cement-solidified in such container, experimental study was carried out as follows. (1) Cement-solidification method. (2) Mechanical behaviour of cement-solidified waste. The mechanical behaviour of the containers was studied by the finite element method and experiment, and the function of pressure-balancing valves was also studied. The following data on processing intermediate level radioactive wastes were obtained. (1) In the case of cement-solidified waste, the data to select the suitable solidifying material and the standard mixing proportion were determined. (2) The basic data concerning the uniaxial compressive strength of cement-solidified waste, the mechanical behaviour of cement-solidified waste packed in a drum under high hydrostatic pressure, the shock response of cement-solidified waste at the time of falling and so on were obtained. (3) The pressure-balancing valves worked at about 0.5 Kg/cm 2 pressure difference inside and outside a container, and the deformation of a drum cover was 10 to 13 mm. In case of the pressure difference less than 0,5 Kg/cm 2 , the valves shut, and water flow did occur. (auth.)

  8. Conceptual design study of fusion experimental reactor (FY86FER)

    International Nuclear Information System (INIS)

    Nakashima, Kunihiko; Yamamoto, Shin; Ohara, Yoshihiro; Watanabe, Kazuhiro; Mizuno, Makoto; Araki, Masanori; Uede, Taisei; Okano, Kunihiko.

    1987-09-01

    This report describes the results of applicability studies for the negative ion-based neutral beam injector to the Fusion Experimental Reactor (FER). The operation scenario of FER has been proposed to adopt the neutral injection method as one of candidates, which has three functions of heating, current drive and profile control. One of the fundamental requirements is the tangential injection of the neutral beam. For neutral beam injectors, three port sections are available. Supposing to adopt the beam line with the straight long neutralizer which has been designed in JAERI, the geometrical arrangement was determined so as to avoid any trouble to the reactor structure. The conceptual study for major components which compose the beam line system was carried out including the estimation of the neutron streaming. The power supply system was studied also and the work was concentrated on the acceleration power supply which requires the output voltage of 500 kV and fast cut-off time. A basic concept, in which a inverter with a AC switch is used and the frequency of the supplied AC line is increased was proposed. In these works, the configuration of the neutral beam injection system was detailed and it was shown that the beam line seems to be well implemented with the geometrical constraints related to the reactor configuration. (author)

  9. Biocompatibility of Plastic Clip in Neurocranium - Experimental Study on Dogs.

    Science.gov (United States)

    Delibegovic, Samir; Dizdarevic, Kemal; Cickusic, Elmir; Katica, Muhamed; Obhodjas, Muamer; Ocus, Muhamed

    2016-01-01

    A potential advantage of the use of the plastic clips in neurosurgery is their property of causing fewer artifacts than titanium clips as assessed by computed tomography and magnetic resonance scans. The biocompatibility of plastic clips was demonstrated in the peritoneal cavity, but their behavior in the neurocranium is not known. Twelve aggressive stray dogs designated for euthanasia were taken for this experimental study. The animals were divided into two groups. In all cases, after anesthesia, a craniotomy was performed, and after opening the dura, a proximal part titanium clip was placed on the isolated superficial Sylvian vein (a permanent Yasargil FT 746 T clip at a 90° angle, while a plastic Hem-o-lok clip ML was placed on another part of the vein). The first group of animals was sacrificed on the 7 th postoperative day and the second group on the 60 th postoperative day. Samples of tissue around the clips were taken for a histopathological evaluation. The plastic clip caused a more intensive tissue reaction than the titanium clip on the 7 th postoperative day, but there was no statistical difference. Even on the 60 th postoperative day there was no significant difference in tissue reaction between the titanium and plastic clips. These preliminary results confirm the possibility for the use of plastic clips in neurosurgery. Before their use in human neurosurgery, further studies are needed to investigate the long-term effects of the presence of plastic clips in the neurocranium, as well as studies of the aneurysmal model.

  10. Experimental studies on catalytic hydrogen recombiners for light water reactors

    International Nuclear Information System (INIS)

    Drinovac, P.

    2006-01-01

    In the course of core melt accidents in nuclear power plants a large amount of hydrogen can be produced and form an explosive or even detonative gas mixture with aerial oxygen in the reactor building. In the containment atmosphere of pressurized water reactors hydrogen combines a phlogistically with the oxygen present to form water vapor even at room temperature. In the past, experimental work conducted at various facilities has contributed little or nothing to an understanding of the operating principles of catalytic recombiners. Hence, the purpose of the present study was to conduct detailed investigations on a section of a recombiner essentially in order to deepen the understanding of reaction kinetics and heat transport processes. The results of the experiments presented in this dissertation form a large data base of measurements which provides an insight into the processes taking place in recombiners. The reaction-kinetic interpretation of the measured data confirms and deepens the diffusion theory - proposed in an earlier study. Thus it is now possible to validate detailed numeric models representing the processes in recombiners. Consequently the present study serves to broaden and corroborate competence in this significant area of reactor technology. In addition, the empirical knowledge thus gained may be used for a critical reassessment of previous numeric model calculations. (orig.)

  11. Conceptual design study of fusion experimental reactor (FY86FER)

    International Nuclear Information System (INIS)

    Nakashima, Kunihiko; Ishigaki, Yukio; Ozaki, Akira; Yamane, Minoru.

    1987-09-01

    This report describes the results of the capacity estimation for the electrical power system on the typical two candidates for the FER (Fusion Experimental Reactor) which were picked out through the process of '86 FER scoping studies. Main concern in the electrical systems is coil power supplies which have a capacity of about 1 GW, and this is dominated by poloidal coil power supplies. Then, studies to reduce the converter capacity are concentrated on the poloidal coil power system in relation to the sypplying poloidal flux at the initial phase of plasma ramp-up. A quench protection circuit was proposed on the toroidal coil power supply. On the position control power supply, a circuit with reasonable functions was proposed. Under these system studies, general specifications were determined and the capacity of each power supply unit was estimated. On the poloidal coil power supply system, the accumulated capacity of converters amounted to 885 MW for the one candidate and 782 MW for another. (author)

  12. Experimental study of bubbly flow using image processing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Yucheng, E-mail: ycfu@vt.edu; Liu, Yang, E-mail: liu130@vt.edu

    2016-12-15

    This paper presents an experimental study of bubbly flows at relatively high void fractions using an advanced image processing method. Bubble overlapping is a common problem in such flows and the past studies often treat the overlapping bubbles as a whole, which introduces considerable measurement uncertainties. In this study, a hybrid method combining intersection point detection and watershed segmentation is used to separate the overlapping bubbles. In order to reconstruct bubbles from separated segments, a systematic procedure is developed which can preserve more features captured in the raw image compared to the simple ellipse fitting method. The distributions of void fraction, interfacial area concentration, number density and velocity are obtained from the extracted bubble information. High-speed images of air-water bubbly flows are acquired and processed for eight test runs conducted in a 30 mm × 10 mm rectangular channel. The developed image processing scheme can effectively separate overlapping bubbles and the results compare well with the measurements by the gas flow meter and double-sensor conductivity probe. The development of flows in transverse and mainstream directions are analyzed and compared with the prediction made by the one-dimensional interfacial area transport equation (IATE) and the bubble number density transport equation.

  13. An experimental study of praseodymium intermetallic compounds at low temperatures

    International Nuclear Information System (INIS)

    Greidanus, F.J.A.M.

    1982-01-01

    In this thesis the author studies the low temperature properties of praseodymium intermetallic compounds. In chapter 2 some of the techniques used for the experiments described in the subsequent chapters are discussed. A set-up to perform specific-heat experiments below 1 K and a technique for performing magnetic susceptibility measurments below 1 K, using a superconducting quantum interference device (SQUID) are described. Chapter 3 is devoted to the theory of interacting Pr 3+ ions. Both bilinear and biquadratic interactions are dealt with in a molecular-field approximation. It is shown that first as well as second-order phase transitions can occur, depending on the nature of the ground state, and on the ratio of magnetic to crystal-field interactions. In chapters 4, 5, 6 and 7 experimental results on the cubic Laves phase compounds PrRh 2 , PrIr 2 , PrPt 2 , PrRu 2 and PrNi 2 are presented. From inelastic neutron scattering experiments the crystalline electric field parameters of the above compounds are determined. In chapters 5 and 6 susceptibility, neutron-diffraction, hyperfine specific-heat, low-field magnetization, pulsed-field magnetization, specific-heat and resistivity measurements are presented. In chapter 7 the specific heat and differential susceptibility of PrNi 2 below 1 K are studied. Finally, in chapter 8 praseodymium intermetallic compounds with low-symmetry singlet ground states, and cubic compounds with magnetic doublet ground states are studied. (Auth.)

  14. Experimental Study of Shock Generated Compressible Vortex Ring

    Science.gov (United States)

    Das, Debopam; Arakeri, Jaywant H.; Krothapalli, Anjaneyulu

    2000-11-01

    Formation of a compressible vortex ring and generation of sound associated with it is studied experimentally. Impulse of a shock wave is used to generate a vortex ring from the open end of a shock-tube. Vortex ring formation process has been studied in details using particle image Velocimetry (PIV). As the shock wave exits the tube it diffracts and expands. A circular vortex sheet forms at the edge and rolls up into a vortex ring. Far field microphone measurement shows that the acoustic pressure consists of a spike due to shock wave followed by a low frequency pressure wave of decaying nature, superimposed with high frequency pressure wave. Acoustic waves consist of waves due to expansion, waves formed in the tube during diaphragm breakage and waves associated with the vortex ring and shear-layer vortices. Unsteady evolution of the vortex ring and shear-layer vortices in the jet behind the ring is studied by measuring the velocity field using PIV. Corresponding vorticity field, circulation around the vortex core and growth rate of the vortex core is calculated from the measured velocity field. The velocity field in a compressible vortex ring differs from that of an incompressible ring due to the contribution from both shock and vortex ring.

  15. Experimental study of nylon fibre reinforced RC beams

    International Nuclear Information System (INIS)

    Ansari, A.A.; Jokhio, S.; Qazi, Attiq-ur-Rehman

    2002-01-01

    Six concrete beams reinforced with Nylon fibre strands placed in tensile zone as an alternative of steel bars have been tested. Fibre of 1.2 mm dia was used and 10 pieces were twisted together to form the strand; the number of turns being a parameter of study. This was done in order to over come the problem of bond, because the surface of fibre is very smooth and slippery. Two strands were used in each beam and in order to eliminate possibility of premature failure due to bond, specially designed End-Steel Anchorages were also tried. All the beams were 1000 mm long and 50 x 100 mm in cross section with an affective span of 900 mm. The tensile behaviors as well as moduli of the fibre itself were also determined. No shear reinforcement was used. The results are encourage and comparative financial study shows that this material holds promise for future use. However, more experimental study is needed. (author)

  16. Experimental studies concerning the drying of voloxidizer off-gases

    International Nuclear Information System (INIS)

    Holland, W.D.; Shah, A.H.; Kaiser, A.F.; McGee, J.C.

    1981-07-01

    The results of an experimental program conducted to aid in the design of a tritium retention system to remove tritiated water from voloxidizer off-gases are presented. The retention system is expected to be a fixed-bed adsorption unit using a commercially available desiccant, such as molecular sieves, to dry the off-gases. The presence of iodine in the off-gas stream somewhat complicates the drying process since some iodine will be retained in the drying bed along with the tritiated water. The present work represents a follow-up to a study in which a small-scale (2-in.-diam by 30-in.-long) packed column of Linde Molecular Sieves (LMS) type 3A was repeatedly loaded and regenerated using a non-radioactive simulated voloxidizer off-gas containing water and iodine vapor. Both water and iodine loadings were measured and the regeneration characteristics of the bed were observed. The following studies were carried out: (1) testing of other desiccants showed LMS type 3A to be superior because of its high water loading and low iodine retention; (2) development of a column-mounted moisture detector; (3) adsorption isotherms; (4) iodine analysis using a commercial oxidant monitor; (5) tests on cartridge-type beds - a series of tests were conducted using three small drying beds connected in series. One further finding of this study was the importance of the clay binder (used in pelletized molecular sieves) in obtaining satisfactory or acceptably low iodine retention

  17. An experimental study of the bandwagon effect in conspicuous consumption

    Directory of Open Access Journals (Sweden)

    Małgorzata Niesiobędzka

    2017-05-01

    Full Text Available Background The phenomenon of conspicuous consumption is not new. Veblen (1994, 1899 described conspicuous consumption as expensive, luxury consumption, which provides evidence of wealth and status. In post-modern society the primary objects of consumption have become images and experience used by the middle class and the masses to demonstrate uniqueness or similarity with significant others. This paper focuses on the bandwagon effect in conspicuous consumption. In the study the bandwagon effect is treated as increased demand for luxury goods due to their popularity, especially among famous people. Participants and procedure Three studies were carried out. The samples consisted of 60 teenagers, 76 female students and 73 students and postgraduate students. The concept of the aspirational group was induced through the advertisement of a luxury product with reference to famous people and by direct reference to the aspirational group. Three different methods to measure a propensity to conspicuous consumption were applied: the amount of money spent on the luxury product, the size of the luxury brand logo, and the doubling of the luxury brand logo. Results The results show that the activation of the idea of the aspirational group enhances willingness to pay more for a luxury product, to double the luxury brand logo and the preference for a visible luxury brand logo at a tendency level. Conclusions The results experimentally supported the bandwagon effect within luxury conspicuous consumption previously established in correlative studies.

  18. [Crystalline lens photodisruption using femtosecond laser: experimental study].

    Science.gov (United States)

    Chatoux, O; Touboul, D; Buestel, C; Balcou, P; Colin, J

    2010-09-01

    The aim of this study was to analyze the interactions during femtosecond (fs) laser photodisruption in ex vivo porcine crystalline lenses and to study the parameters for laser interaction optimization. An experimental femtosecond laser was used. The laser characteristics were: 1030 nm wavelength; pulse duration, 400 fs; and numerical aperture, 0.13. Specific software was created to custom and monitor any type of photoablation pattern for treatment purposes. Porcine crystalline lenses were placed in an open sky holder filled with physiological liquid (BSS) covered by a glass plate. A numerical camera was associated with metrological software in order to magnify and quantify the results. Transmission electron microscopy (TEM) was performed on some samples to identify the microscopic plasma interactions with the lens. The optimization of parameters was investigated in terms of the optical breakdown threshold, the sizing of interactions, and the best pattern for alignments. More than 150 crystalline lenses of freshly enucleated pigs were treated. The optical breakdown threshold (OBT) was defined as the minimal energy level per pulse necessary to observe a physical interaction. In our study, the OBT varied according to the following parameters: the crystalline lens itself, varying from 4.2 to 7.6 μJ (mean, 5.1 μJ), and the depth of laser focus, varying up to 1 μJ, increasing in the depth of the tissue. Analyzing the distance between impacts, we observed that the closer the impacts were the less power was needed to create a clear well-drawn defect pattern (lines), i.e., with a 4-μJ optimized OBT, when the impacts were placed every 2 μm for the x,y directions and 60 μm for the z direction. Coalescent bubbles created by plasma formation always disappeared in less than 24h. The nonthermal effect of plasma and the innocuousness on surrounding tissues were proven by the TEM results. The crystalline lens photodisruption by the femtosecond laser seems an innovative

  19. Proteomic Studies on Human and Experimental Cerebral Malaria

    KAUST Repository

    Moussa, Ehab

    2012-07-01

    Cerebral malaria (CM) is a severe neurological complication of malaria infection that results from interrelated pathologies. Despite extensive research efforts, the mechanism of the disease is not completely understood. Clinical studies, postmortem analysis, and animal models have been the main research arenas in CM. In this thesis, shotgun proteomics approach was used to further understand the pathology of human and experimental CM. The mechanism by which CM turns fatal is yet to be identified. A clinical proteomics study was conducted on pooled plasma samples from children with reversible or fatal CM from the Gambia. The results show that depletion of coagulation factors and increased levels of circulating proteasomes are associated with fatal pediatric CM. This data suggests that the ongoing coagulation during CM might be a disseminated intravascular coagulation state that eventually causes depletion of the coagulation factors leading to petechial hemorrhages. In addition, the mechanism(s) by which blood transfusion benefits CM in children was investigated. To that end, the concentration and multimerization pattern of von-willebrand factor, and the concentration of haptoglobin in the plasma of children with CM who received blood transfusions were measured. In addition to clinical studies, experimental cerebral malaria (ECM) in mice has been long used as a model for the disease. A shotgun proteomics workflow was optimized to identify the proteomic signature of the brain tissue of mice with ECM.Because of the utmost importance of membrane proteins in the pathology of the disease, sample fractionation and filter aided sample preparation were used to recover them. The proteomic signature of the brains of mice infected with P. berghei ANKA that developed neurological syndrome, mice infected with P. berghei NK56 that developed severe malaria but without neurological signs, and non-infected mice, were compared to identify CM specific proteins. Among the differentially

  20. Experimental, theoretical, and numerical studies of small scale combustion

    Science.gov (United States)

    Xu, Bo

    Recently, the demand increased for the development of microdevices such as microsatellites, microaerial vehicles, micro reactors, and micro power generators. To meet those demands the biggest challenge is obtaining stable and complete combustion at relatively small scale. To gain a fundamental understanding of small scale combustion in this thesis, thermal and kinetic coupling between the gas phase and the structure at meso and micro scales were theoretically, experimentally, and numerically studied; new stabilization and instability phenomena were identified; and new theories for the dynamic mechanisms of small scale combustion were developed. The reduction of thermal inertia at small scale significantly reduces the response time of the wall and leads to a strong flame-wall coupling and extension of burning limits. Mesoscale flame propagation and extinction in small quartz tubes were theoretically, experimentally and numerically studied. It was found that wall-flame interaction in mesoscale combustion led to two different flame regimes, a heat-loss dominant fast flame regime and a wall-flame coupling slow flame regime. The nonlinear transition between the two flame regimes was strongly dependent on the channel width and flow velocity. It is concluded that the existence of multiple flame regimes is an inherent phenomenon in mesoscale combustion. In addition, all practical combustors have variable channel width in the direction of flame propagation. Quasi-steady and unsteady propagations of methane and propane-air premixed flames in a mesoscale divergent channel were investigated experimentally and theoretically. The emphasis was the impact of variable cross-section area and the flame-wall coupling on the flame transition between different regimes and the onset of flame instability. For the first time, spinning flames were experimentally observed for both lean and rich methane and propane-air mixtures in a broad range of equivalence ratios. An effective Lewis number

  1. Experimental and numerical study of the British Experimental Rotor Programme blade

    Science.gov (United States)

    Brocklehurst, Alan; Duque, Earl P. N.

    1990-01-01

    Wind-tunnel tests on the British Experimental Rotor Programme (BERP) tip are described, and the results are compared with computational fluid dynamics (CFD) results. The test model was molded using the Lynx-BERP blade tooling to provide a semispan, cantilever wing comprising the outboard 30 percent of the rotor blade. The tests included both surface-pressure measurements and flow visualization to obtain detailed information of the flow over the BERP tip for a range of angles of attack. It was observed that, outboard of the notch, favorable pressure gradients exist which ensure attached flow, and that the tip vortex also remains stable to large angles of attack. On the rotor, these features yield a very gradual break in control loads when the retreating-blade limit is eventually reached. Computational and experimental results were generally found to be in good agreement.

  2. A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Chen Zhu

    2006-08-31

    Currently, DOE is conducting pilot CO{sub 2} injection tests to evaluate the concept of geological sequestration. One strategy that potentially enhances CO{sub 2} solubility and reduces the risk of CO{sub 2} leak back to the surface is dissolution of indigenous minerals in the geological formation and precipitation of secondary carbonate phases, which increases the brine pH and immobilizes CO{sub 2}. Clearly, the rates at which these dissolution and precipitation reactions occur directly determine the efficiency of this strategy. However, one of the fundamental problems in modern geochemistry is the persistent two to five orders of magnitude discrepancy between laboratory measured and field derived feldspar dissolution rates. To date, there is no real guidance as to how to predict silicate reaction rates for use in quantitative models. Current models for assessment of geological carbon sequestration have generally opted to use laboratory rates, in spite of the dearth of such data for compositionally complex systems, and the persistent disconnect between laboratory and field applications. Therefore, a firm scientific basis for predicting silicate reaction kinetics in CO2 injected geological formations is urgently needed to assure the reliability of the geochemical models used for the assessments of carbon sequestration strategies. The funded experimental and theoretical study attempts to resolve this outstanding scientific issue by novel experimental design and theoretical interpretation to measure silicate dissolution rates and iron carbonate precipitation rates at conditions pertinent to geological carbon sequestration. In the second year of the project, we completed CO{sub 2}-Navajo sandstone interaction batch and flow-through experiments and a Navajo sandstone dissolution experiment without the presence of CO{sub 2} at 200 C and 250-300 bars, and initiated dawsonite dissolution and solubility experiments. We also performed additional 5-day experiments at the

  3. Experimental study on the Ranque-Hilsch vortex tube

    NARCIS (Netherlands)

    Gao, C.

    2005-01-01

    The Ranque-Hilsch vortex tube cooler (RHVT) has been investigated in the Low Temperature Group at Eindhoven University of Technology. The research was focussed on a thorough experimental investigation of the flow inside the system at a large variety of experimental conditions. Three measurement

  4. Experimental and analytical studies of sodium interactions with various concretes

    International Nuclear Information System (INIS)

    Suo-Anttila, A.; Smaardyk, J.E.

    1982-01-01

    Mechanistic models of sodium/concrete interactions are described. The SCAM model of interactions with basaltic concrete is being verified by experiments. Modelling of sodium interactions with limestone concrete is still at a preliminary stage but shows promise of being able to predict quantitatively the experimental data. Comparisons with experimental data are presented

  5. An experimental study on suspended sodium droplet combustion

    International Nuclear Information System (INIS)

    Sato, Kenji

    2003-03-01

    As part of studies for phenomenological investigation of sodium droplet burning behavior, in our previous experimental studies, ignition process and succeeding combustion of suspended single sodium droplet had been investigated by using high speed movie camera, and a temperature measurement system feasible for the experiment had been developed. In the present study, by using 4 mm diam. suspended sodium droplet, combustion experiments were performed for the free-stream velocity of dry air flow of 20 to 60 cm/s, and for the initial droplet temperature of 280 to 400degC, and the effects of the free-stream velocity and initial droplet temperature on the ignition behavior and droplet temperature variation with time were examined by using high speed movie camera and sheath-type fine thermocouple. The experimental results are as follows: (1) When the initial droplet temperature is less than 290degC, before ignition the oxide film accompanied with vertical streak appeared and the droplet turned to teardrop shape. (2) The ignition delay time defined as the time to evolution of orange color light emission zone or flame zone decreases with the increase o the free-stream velocity or of initial droplet temperature. Examples of typical ignition time are 1.4 s at the free-stream velocity 20 cm/s and initial droplet temperature 300degC, and 0.65 s at 60 cm/s and 400degC. (3) the dependence of the ignition delay time on the free-stream velocity decreases as the free stream velocity increases. (4) The droplet temperatures at the moment of melting extending all over the surface and at the moment of ignition are around 460degC and 500 to 600degC (mostly around 575degC), respectively. These values are essentially independent of the free-stream velocity and initial droplet temperature. (5) The rate of temperature rise does not change through the moment of ignition. (6) The asymptotic droplet temperature at approaching to quasi-steady combustion state following ignition is independent of

  6. Experimental study of fast electron transport in dense plasmas

    International Nuclear Information System (INIS)

    Vaisseau, Xavier

    2014-01-01

    The framework of this PhD thesis is the inertial confinement fusion for energy production, in the context of the electron fast ignition scheme. The work consists in a characterization of the transport mechanisms of fast electrons, driven by intense laser pulses (10 19 - 10 20 W/cm 2 ) in both cold-solid and warm-dense matter. The first goal was to study the propagation of a fast electron beam, characterized by a current density ≥ 10 11 A/cm 2 , in aluminum targets initially heated close to the Fermi temperature by a counter-propagative planar shock. The planar compression geometry allowed us to discriminate the energy losses due to the resistive mechanisms from collisional ones by comparing solid and compressed targets of the same initial areal densities. We observed for the first time a significant increase of resistive energy losses in heated aluminum samples. The confrontation of the experimental data with the simulations, including a complete characterization of the electron source, of the target compression and of the fast electron transport, allowed us to study the time-evolution of the material resistivity. The estimated resistive electron stopping power in a warm-compressed target is of the same order as the collisional one. We studied the transport of the fast electrons generated in the interaction of a high-contrast laser pulse with a hollow copper cone, buried into a carbon layer, compressed by a counter-propagative planar shock. A X-ray imaging system allowed us to visualize the coupling of the laser pulse with the cone at different moments of the compression. This diagnostic, giving access to the fast electron spatial distribution, showed a fast electron generation in the entire volume of the cone for late times of compression, after shock breakout from the inner cone tip. For earlier times, the interaction at a high-contrast ensured that the source was contained within the cone tip, and the fast electron beam was collimated into the target depth by

  7. Experimental and theoretical study of cascade solar stills in Iran

    International Nuclear Information System (INIS)

    Tabrizi, F.F.; Sharak, A.Z.

    2009-01-01

    Due to low annual rainfall, most of Iran is dominated by arid and semi-arid areas. The solar radiation intensity is extremely high in most of the country. The need to produce fresh water from brackish water is considerably high, especially in dry regions. Desalination of brackish water may become a competitive potential water resource to meet potable water demand, and as the price of oil goes higher, using solar energy for water desalinisation becomes more economical. This paper presented a study that involved mathematical modeling of the first solar still in Iran. The cumulative fresh water production and water temperature were calculated as a function of time. The obtained results were verified by one month daily-based experimental data. The paper also provided background information on the Koshk village, situated in the south part of Iran near Badar Abbas city. Various investigations regarding meteorological conditions, economical considerations, and technical and operational appropriateness demonstrated that the cascade solar still is suitable for desalination of brackish water. 100 solar stills were installed at the site to provide potable water for a nearby village. It was concluded that the model could be used to simulate and optimize the effective design parameters in future studies. 6 refs., 7 figs

  8. Experimental studies of tritium barrier concepts for fusion reactors

    International Nuclear Information System (INIS)

    Maroni, V.A.; Van Deventer, E.H.; Renner, T.A.; Pelto, R.H.; Wierdak, C.J.

    1976-01-01

    Ongoing experimental studies at ANL aimed at the development of methods to reduce tritium migration in fusion reactor systems currently include (1) work on the development of multilayered metal composites and impurity-coated refractory metals as barriers to tritium permeation in elevated temperature (greater than 300 0 C) structures and (2) investigations of the kinetics of tritium trapping reactions in inert gas purge streams under conditions that emulate fusion reactor environments. Significant results obtained thus far are (1) demonstration of greater than 50-fold reductions in the hydrogen permeability of stainless steel structures by using stainless steel-clad composites containing an intermediate layer of a selected copper alloy and (2) verification that surface-oxide coatings lead to greater than 100-fold reductions in the hydrogen permeability of vanadium, but that severe oxygen penetration and embrittlement of the vanadium occur at temperatures in the range from 300 to 800 0 C and under conditions of extremely low oxygen potential. Other considerations pertaining to the large-scale use of metal composites in fusion reactors are discussed, and progress in efforts to demonstrate the fabricability of metal composites is reviewed. Also presented are results of studies of the efficiencies of (1) CuO and CuO--MnO 2 beds in converting HT to HTO and (2) magnesium metal beds in converting HTO to HT

  9. Korean experimental studies on the radionuclide transfer in crop plants

    International Nuclear Information System (INIS)

    Choi, Y.H.; Lim, K.M.; Choi, G.S.; Choi, H.J.; Lee, H.S.; Lee, C.W.

    2003-01-01

    In Korea, data on the radionuclide transfer in crop plants have been produced almost exclusively at the Korea Atomic Energy Research Institute (KAERI), where experimental studies have been carried out for last about 20 years. These works are briefly outlined in this paper which shows results with emphasis on rice data. Soil-to-plant transfer factors of radionuclides including radiocesium and radiostrontium were measured through greenhouse experiments for various crop species. Not only conventional transfer factors but also those based on the activity applied to unit area of the soil surface were investigated. Field studies on the transfer of fallout 137 Cs were carried out for rice and Chinese cabbage. As for parameters in relation to direct plant contamination, interception factors and translocation factors were obtained through greenhouse experiments. Plants were sprayed with radioactive solutions containing 54 Mn, 57 Co, 85 Sr, 103 Ru and 134 Cs at different growth stages. Experiments on the plant exposure to airborne HTO and I 2 vapor were also carried out. The transfer parameters generally showed great variations with soils, crops, radionuclides and isotope application times. Most experiments were designed for acute releases of radioactivity but some results are applicable to steady-state conditions, too. Many of the produced data would be of use also in other countries including Japan. (author)

  10. Experimental study on occupant evacuation in narrow seat aisle

    Science.gov (United States)

    Huang, Shenshi; Lu, Shouxiang; Lo, Siuming; Li, Changhai; Guo, Yafei

    2018-07-01

    Narrow seat aisle is an important area in the train car interior due to the large passenger population, however evacuation therein has not gained enough concerns. In this experimental study, the occupant evacuation of the narrow seat aisle area is investigated, with the aisle width of 0.4-0.6 m and the evacuation direction of forward and backward. The evacuation behaviors are analyzed based on the video record, and the discussion is carried out in the aspect of evacuation time, crowdedness, evacuation order, and aisle conflicts. The result shows that with the increasing aisle width, total evacuation time and the average specific evacuation rate decrease. The aisle is crowded for some time, with a large linear occupant densities. The evacuation order of each occupant is mainly related to the seat position. Moreover, it is found that the aisle conflicts can be well described by Burstedde's model. This study gives a useful benchmark for evacuation simulation of narrow seat aisle, and provides reference to safety design of seat area in train cars.

  11. Experimental study on dynamic behavior of large scale foundation, 1

    International Nuclear Information System (INIS)

    Hanada, Kazufumi; Sawada, Yoshihiro; Esashi, Yasuyuki; Ueshima, Teruyuki; Nakamura, Hideharu

    1983-01-01

    The large-sized, high performance vibrating table in the Nuclear Power Engineering Test Center is installed on a large-scale concrete foundation of length 90.9 m, width 44.8 m and maximum thickness 21 m, weighing 150,000 tons. Through the experimental study on the behavior of the foundation, which is set on gravel ground, useful information should be obtained on the siting of a nuclear power plant on the Quaternary stratum ground. The objective of research is to grasp the vibration characteristics of the foundation during the vibration of the table to evaluate the interaction between the foundation and the ground, and to evaluate an analytical method for numerically simulating the vibration behavior. In the present study, the vibration behavior of the foundation was clarified by measurement, and in order to predict the vibration behavior, the semi-infinite theory of elasticity was applied. The accuracy of this analytical method was demonstrated by comparison with the measured results. (Mori, K.)

  12. Sensitivity of MRI in detecting alveolar infiltrates. Experimental studies

    International Nuclear Information System (INIS)

    Biederer, J.; Busse, I.; Grimm, J.; Reuter, M.; Heller, M.; Muhle, C.; Freitag, S.

    2002-01-01

    Purpose: An experimental study using porcine lung explants and a dedicated chest phantom to evaluate the signal intensity of artificial alveolar infiltrates with T 1 - and T 2 -weighted MRI sequences. Material and Methods: 10 porcine lung explants were intubated, transferred into the cavity of a MRI-compatible chest phantom and inflated by continuous evacuation of the artificial pleural space. All lungs were examined with MRI at 1.5 T before and after intra-tracheal instillation of either 100 or 200 ml gelatine-stabilised liquid to simulate alveolar infiltrates. MR-examination comprised gradient echo (2D- and 3D-GRE) and fast spin echo sequences (T 2 -TSE and T 2 -HASTE). The signal intensity of lung parenchyma was evaluated at representative cross sections using a standardised scheme. Control studies were acquired with helical CT. Results: The instilled liquid caused patchy confluent alveolar infiltrates resembling the findings in patients with pneumonia or ARDS. CT revealed typical ground-glass opacities. Before the application of the liquid, only T 2 -HASTE and T 2 -TSE displayed lung parenchyma signals with a signal/noise ratio of 3.62 and 1.39, respectively. After application of the liquid, both T 2 -weighted sequences showed clearly visible infiltrates with an increase in signal intensity of approx. 30% at 100 ml (p 2 -weighted sequences detects artificial alveolar infiltrates with high signal intensity and may be a highly sensitive tool to detect pneumonia in patients. (orig.) [de

  13. Experimental study on active specific immunotherapy modified with irradiation

    International Nuclear Information System (INIS)

    Imanaka, Kazufumi; Ogawa, Yasuhiro; Gose, Kyuhei; Imajo, Yoshinari; Kumura, Shuji

    1982-01-01

    We have already reported that the effectiveness of active specific immunotherapy using irradiated tumor cells and infiltrating mononuclear cells which were separated from the topical tumor tissue 7 days after irradiation of 2,000 rad in experimental study. The present study was designed to investigate the effect of non-specific immunopotentiator PS-K combined with active specific immunotherapy. Female C3H/He mice aged 12 weeks were inoculated 4 x 10 6 MM 46 tumor cells in the right hind paws and received local electron irradiation with the dose of 3,000 rad on the 5th day after irradiation. Active specific immunotherapy was performed on the 12th day, and daily dose of 200 mg/kg of PS-K was injected intraperitoneally from the 6th day to the 10th day. The inhibition of the tumor growth and the elongation of survival period were noted in the group which received active specific immunotherapy combined with non-specific immunopotentiator, PS-K compared with the active specific immunotherapy alone. (author)

  14. Experimental study of fuel sootiness effects on flashover

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Kuang-Chung, E-mail: tsaikc@ccms.nkfust.edu.tw [Dept. of Safety, Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, 2 Juoyue Road, Nantzu, Kaohsiung 811, Taiwan (China); Chen, Hung-Hsiang [Dept. of Safety, Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, 2 Juoyue Road, Nantzu, Kaohsiung 811, Taiwan (China)

    2010-06-15

    Previous fire safety studies have demonstrated that flashover can result in severe injure and death and heat radiating back to a fuel is an important mechanism. Fuel sootiness dominates in radiative heat transfer. However, empirical correlations from previous investigations did not consider the fuel sootiness but nevertheless generated reasonably good predictions of flashover. In this study, a series of experiments was employed to examine fuel sootiness effects on flashover. The fuels used, in the order of their sootiness, were gasoline, n-hexane, iso-propanol and methanol. These fuels were filled in circular pans 100-320 mm in diameter to generate fires with different heat release rates and levels of sootiness. The pans were in 1/3 the size of the ISO 9705 test chamber. After ignition, the heat release rate (HRR), temperature inside the chamber, as well as heat flux on the floor and time to flashover (t{sub fo}) were determined. Experimental data show that HRR at flashover and t{sub fo} were strongly corrected and their relationship was independent of the fuel burned. Although heat feedback to the floor increased as fuel sootiness increased, consequently enhancing the burning of sooty fuels, flashover occurs only when the HRR at flashover criterion is reached.

  15. Theoretical and experimental study of non-monotonous effects

    International Nuclear Information System (INIS)

    Delforge, J.

    1977-01-01

    In recent years, the study of the effects of low dose rates has expanded considerably, especially in connection with current problems concerning the environment and health physics. After having made a precise definition of the different types of non-monotonous effect which may be encountered, for each the main experimental results known are indicated, as well as the principal consequences which may be expected. One example is the case of radiotherapy, where there is a chance of finding irradiation conditions such that the ratio of destructive action on malignant cells to healthy cells is significantly improved. In the second part of the report, the appearance of these phenomena, especially at low dose rates are explained. For this purpose, the theory of transformation systems of P. Delattre is used as a theoretical framework. With the help of a specific example, it is shown that non-monotonous effects are frequently encountered, especially when the overall effect observed is actually the sum of several different elementary effects (e.g. in survival curves, where death may be due to several different causes), or when the objects studied possess inherent kinetics not limited to restoration phenomena alone (e.g. cellular cycle) [fr

  16. Experimental study on performance of pulsed liquid jet pump

    International Nuclear Information System (INIS)

    Xu Weihui; Gao Chuanchang; Qin Haixia

    2010-01-01

    The device performance characteristics of transformer type pulsed liquid pump device were experimentally studied. The effects of the area ratio, work pressure and pulse parameters on the performance of the pulsed liquid jet pump device were performed in the tests. The potency of pulsed jet on improving the performance of the liquid jet pump device was also studied through the comparison with invariable jet pump at the same conditions. The results show that the pulsed jet can significantly improve the performance of transformer type jet pump devices. Area ratio and pulse parameters are the critical factors to the performance of the pulsed liquid jet pump device. The jet pump device performances are significantly improved by reducing the area ratio or by increasing the pulsed frequency. The flux characteristics of the pulsed liquid jet pump device presents the typical negative linear,the potency of pulsed jet in improving the performance of jet pump device with small area ratio can be more significant. The efficiency curve of pulsed liquid jet pump is similar to the parabola. At higher pulsed frequency, the top efficiency point of the pulsed jet pump moves to the higher flow ratio. The high efficiency area of the pulsed jet pump also is widened with the increase of the pulsed frequency. (authors)

  17. Analytical & Experimental Study of Radio Frequency Cavity Beam Profile Monitor

    Energy Technology Data Exchange (ETDEWEB)

    Balcazar, Mario D. [Fermilab; Yonehara, Katsuya [Fermilab

    2017-10-22

    The purpose of this analytical and experimental study is multifold: 1) To explore a new, radiation-robust, hadron beam profile monitor for intense neutrino beam applications; 2) To test, demonstrate, and develop a novel gas-filled Radio-Frequency (RF) cavity to use in this monitoring system. Within this context, the first section of the study analyzes the beam distribution across the hadron monitor as well as the ion-production rate inside the RF cavity. Furthermore a more effecient pixel configuration across the hadron monitor is proposed to provide higher sensitivity to changes in beam displacement. Finally, the results of a benchtop test of the tunable quality factor RF cavity will be presented. The proposed hadron monitor configuration consists of a circular array of RF cavities located at a radial distance of 7cm { corresponding to the standard deviation of the beam due to scatering { and a gas-filled RF cavity with a quality factor in the range 400 - 800.

  18. Experimental study on the particles deposition in the sampling duct

    Energy Technology Data Exchange (ETDEWEB)

    Vendel, J.; Charuau, J. [Institut de Protection et de Surete Nucleaire, Yvette (France)

    1995-02-01

    A high standard of protection against the harmful effects of radioactive aerosol dissemination requires a measurement, as representative as possible, of their concentration. This measurement depends on the techniques used for aerosol sampling and transfer to the detector, as well as on the location of the latter with respect to the potential sources. The aeraulic design of the apparatus is also an important factor. Once collected the aerosol particles often have to travel through a variably shaped duct to the measurement apparatus. This transport is responsible for losses due to the particles deposition on the walls, leading to a distortion on the concentration measurements and a change in the particle size distribution. To estimate and minimize measurement errors it is important to determine the optimal transport conditions when designing a duct; its diameter and material, the radius of curvature of the bends and the flow conditions must be defined in particular. This paper presents an experimental study in order to determine, for each deposition mechanism, the retained fraction, or the deposition velocity for different flow regimes. This study has pointed out that it exists a favourable flow regime for the particle transport through the sampling ducts (2 500 < Re < 5 000). It has been established, for any particle diameters, equations to predict the aerosol penetration in smooth-walled cylindrical metal ducts.

  19. Experimental Study on Pipe Sections against Impact Loading

    Directory of Open Access Journals (Sweden)

    Engin GÜCÜYEN

    2018-02-01

    Full Text Available Pipelines are significant structural systems that transfer necessary materials from one place to another. They are under the effect of static and dynamic loads during their service lives. Investigations have become important to determine the effects of sudden dynamic loads with technological developments. Researchers study the mechanical properties of different materials and structural members under dynamic effects such as earthquake, wind, blast, rock falling and vehicle crushing. For this purpose, different test setups have been developed to investigate the behaviour of test members. In this study, galvanized and water filled galvanized pipe sections having three different diameter values are produced in a laboratory to perform tests under impact loading. The behaviour of the pipes is determined by free falling test apparatus. In addition, measurement devices as accelerometer, dynamic force sensor, lvdt, and data logger are used in the experimental program. So, acceleration, impact force, and displacement values are obtained during the tests. Besides, damage developments of the pipes are also observed to determine the impact resistances of test members. The results are compared to each other and it is stated that while acceleration and impact force values decrease, displacement values increase as the test members approach to collapse damage situation.

  20. A Randomized Controlled Pilot Trial of Classroom-Based Mindfulness Meditation Compared to an Active Control Condition in 6th Grade Children

    Science.gov (United States)

    Britton, Willoughby B.; Lepp, Nathaniel E.; Niles, Halsey F.; Rocha, Tomas; Fisher, Nathan; Gold, Jonathan

    2014-01-01

    Children in the United States are at risk for numerous psychological problems, such as anxiety, attention problems, and mood disorders, and are underserved by current mental health provisions. The current study is a pilot trial to examine the effects of a nonelective, classroom-based, teacher-implemented, mindfulness meditation intervention on standard clinical measures of mental health and affect in middle school children. A total of 101 healthy sixth-grade students (55 boys and 46 girls) were randomized to either an Asian history course with daily mindfulness meditation practice (intervention group) or an African history course with a matched experiential activity (active control group). Self-reported data was collected by administering the Youth Self Report (YSR), a modified Spielberger State-Trait Anxiety Inventory, and the Cognitive and Affective Mindfulness Measure -Revised before and after 6 weeks of meditation or active control condition. Both meditators and active controls decreased significantly on the YSR Internalizing Problems, Externalizing Problems, and Attention Problems subscales but did not differ in the extent of their improvements. Both groups also showed comparable improvements on measures in affect. Meditators were significantly less likely to develop suicidal ideation or thoughts of self-harm than controls. Improvements in affect were correlated with increases in mindfulness in meditators but not controls. These results suggest that mindfulness training may yield both unique and nonspecific benefits that are shared by other novel activities. PMID:24930819

  1. Experimental study of a 1 MW, 170 GHz gyrotron oscillator

    Science.gov (United States)

    Kimura, Takuji

    A detailed experimental study is presented of a 1 MW, 170 GHz gyrotron oscillator whose design is consistent with the ECH requirements of the International Thermonuclear Experimental Reactor (ITER) for bulk heating and current drive. This work is the first to demonstrate that megawatt power level at 170 GHz can be achieved in a gyrotron with high efficiency for plasma heating applications. Maximum output power of 1.5 MW is obtained at 170.1 GHz in 85 kV, 50A operation for an efficiency of 35%. Although the experiment at MIT is conducted with short pulses (3 μs), the gyrotron is designed to be suitable for development by industry for continuous wave operation. The peak ohmic loss on the cavity wall for 1 MW of output power is calculated to be 2.3 kW/cm2, which can be handled using present cooling technology. Mode competition problems in a highly over-moded cavity are studied to maximize the efficiency. Various aspects of electron gun design are examined to obtain high quality electron beams with very low velocity spread. A triode magnetron injection gun is designed using the EGUN simulation code. A total perpendicular velocity spread of less than 8% is realized by designing a low- sensitivity, non-adiabatic gun. The RF power is generated in a short tapered cavity with an iris step. The operating mode is the TE28,8,1 mode. A mode converter is designed to convert the RF output to a Gaussian beam. Power and efficiency are measured in the design TE28,8,1 mode at 170.1 GHz as well as the TE27,8,1 mode at 166.6 GHz and TE29,8,1 mode at 173.5 GHz. Efficiencies between 34%-36% are consistently obtained over a wide range of operating parameters. These efficiencies agree with the highest values predicted by the multimode simulations. The startup scenario is investigated and observed to agree with the linear theory. The measured beam velocity ratio is consistent with EGUN simulation. Interception of reflected beam by the mod-anode is measured as a function of velocity ratio

  2. Drug induced acute kidney injury: an experimental animal study

    International Nuclear Information System (INIS)

    Khan, M.W.A.; Khan, B.T.; Qazi, R.A.; Ashraf, M.; Waqar, M.

    2017-01-01

    Objective: To assess the extent of drug induced nephrotoxicity in laboratory animals for determining the role and extent of iatrogenic kidney damage in patients exposed to nephrotoxic drugs in various clinical setups. Study Design: Randomized control trail. Place and Duration of study: Pharmacology department and animal house of Army Medical College from Jan 2011 to Aug 2011. Material and Methods: Thirty six mixed breed rabbits were used in this study. Animals were randomly divided into six groups consisting of six rabbits in each. Groups were named A, B, C, D, E and F. Group A was control group. Group B was given 0.9% normal saline. Group C rabbits were given acute nephrotoxic single dose of amphotericin B deoxycholate. Group D received 0.9% normal saline 10ml/kg followed by amphotericin B infusion. Group E was injected acute nephrotoxic regimen of cyclosporine and amphotericin B infusion. Group F received saline loading along with acute nephrotoxic regimen of cyclosporine and amphotericin B infusion. Results: Biochemical and histopathological analysis showed significant kidney injury in rabbits exposed to acute nephrotoxic doses of amphotericin B and cyclosporine. Toxicity was additive when the two drugs were administered simultaneously. Group of rabbits with saline loading had significantly lesser kidney damage. Conclusion: Iatrogenic acute kidney damage is a major cause of morbidity in experimental animals exposed to such nephrotoxic drugs like amphotericin B and cyclosporine, used either alone or in combination. Clinical studies are recommended to assess the extent of iatrogenic renal damage in patients and its economic burden. Efficient and cost effective protective measure may be adopted in clinical setups against such adverse effects. (author)

  3. Experimental study of a high intensity radio-frequency cooler

    Directory of Open Access Journals (Sweden)

    Ramzi Boussaid

    2015-07-01

    Full Text Available Within the framework of the DESIR/SPIRAL-2 project, a radio-frequency quadrupole cooler named SHIRaC has been studied. SHIRaC is a key device of SPIRAL-2, designed to enhance the beam quality required by DESIR. The preliminary study and development of this device has been carried out at Laboratoire de Physique Corpusculaire de CAEN (LPC Caen, France. The goal of this paper is to present the experimental studies conducted on a SHIRaC prototype. The main peculiarity of this cooler is its efficient handling and cooling of ion beams with currents going up as high as 1  μA which has never before been achieved in any of the previous coolers. Much effort has been made lately into these studies for development of appropriate optics, vacuum and rf systems which allow cooling of beams of large emittance (∼80π  mm mrad and high current. The dependencies of SHIRaC’s transmission and the cooled beam parameters in terms of geometrical transverse emittance and the longitudinal energy spread have also been discussed. Investigation of beam purity at optimum cooling condition has also been done. Results from the experiments indicate that an emittance reduction of less than 2.5π  mm mrad and a longitudinal energy spread reduction of less than 4 eV are obtained with more than 70% of ion transmission. The emittance is at expected values whereas the energy spread is not.

  4. Numerical and experimental studies of droplet-gas flow

    Energy Technology Data Exchange (ETDEWEB)

    Joesang, Aage Ingebret

    2002-07-01

    This thesis considers droplet-gas flow by the use of numerical methods and experimental verification. A commercial vane separator was studied both numerical and by experiment. In addition some efforts are put into the numerical analysis of cyclones. The experimental part contains detailed measurements of the flow field between a pair of vanes in a vane separator and droplet size measurements. LDA (Laser Doppler Anemometry) was used to measure the velocity in two dimensions and corresponding turbulence quantities. The results from the LDA measurements are considered to be of high quality and are compared to numerical results obtained from a CFD (Computational Fluid Dynamics) analysis. The simulation showed good agreement between the numerical and experimental results. Combinations of different turbulence models; the standard k-epsilon model and the Reynold Stress Mode, different schemes; first order and higher order scheme and different near wall treatment of the turbulence; the Law of the wall and the Two-Layer Zonal model were used in the simulations. The Reynold Stress Model together with a higher order scheme performed rather poorly. The recirculation in parts of the separator was overpredicted in this case. For the other cases the overall predictions are satisfactory. PDA (Phase Doppler Anemometry) measurements were used to study the changes in the droplet size distribution through the vane separator. The PDA measurements show that smaller droplets are found at the outlet than present at the inlet. In the literature there exists different mechanisms for explaining the re-entrainment and generation of new droplets. The re-entrainments mechanisms are divided into four groups where droplet-droplet interaction, droplet break-up, splashing of impinging droplet and re-entrainment from the film are defined as the groups of re-entrainment mechanisms. Models for these groups are found in the literature and these models are tested for re-entrainment using the operational

  5. Experimental Studies of Elementary Particle Interactions at High Energies

    Energy Technology Data Exchange (ETDEWEB)

    Goulianos, Konstantin [Rockefeller Univ., New York, NY (United States)

    2013-07-30

    This is the final report of a program of research on "Experimental Studies of Elementary Particle Interactions at High Energies'' of the High Energy Physics (HEP) group of The Rockefeller University. The research was carried out using the Collider Detector at Fermilab (CDF) and the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) at CERN. Three faculty members, two research associates, and two postdoctoral associates participated in this project. At CDF, we studied proton-antiproton collisions at an energy of 1.96 TeV. We focused on diffractive interactions, in which the colliding antiproton loses a small fraction of its momentum, typically less than 1%, while the proton is excited into a high mass state retaining its quantum numbers. The study of such collisions provides insight into the nature of the diffractive exchange, conventionally referred to as Pomeron exchange. In studies of W and Z production, we found results that point to a QCD-based interpretation of the diffractive exchange, as predicted in a data-driven phenomenology developed within the Rockefeller HEP group. At CMS, we worked on diffraction, supersymmetry (SUSY), dark matter, large extra dimensions, and statistical applications to data analysis projects. In diffraction, we extended our CDF studies to higher energies working on two fronts: measurement of the single/double diffraction and of the rapidity gap cross sections at 7 TeV, and development of a simulation of diffractive processes along the lines of our successful model used at CDF. Working with the PYTHIA8 Monte Carlo simulation authors, we implemented our model as a PYTHIA8-MBR option in PYTHIA8 and used it in our data analysis. Preliminary results indicate good agreement. We searched for SUSY by measuring parameters in the Constrained Minimal Supersymmetric extension of the Standard Model (CMSSM) and found results which, combined with other experimental constraints and theoretical considerations, indicate

  6. An experimental study of tumour size and radiosensitivity

    International Nuclear Information System (INIS)

    Hill, S.A.; Denekamp, J.

    1989-01-01

    When designing experimental studies of tumours, it is considered important to control all variables that might alter the radiosensitivity and hence influence the variability of the data. One such variable is tumour size. We have studied the regrowth delay of a mammary carcinoma treated at 2-10 mm mean diameter (a 125-fold change of volume) with X-rays alone or X-rays plus misonidazole (MISO). The data were analysed to give dose-response curves, using four endpoints. Regrowth to a fixed size (4.5 mm larger than treatment size), or by a fixed increment (4 times the original volume) was expressed either as absolute delay, or as specific growth delay to allow for the changes in volume doubling time as the tumour grows. The method of analysis made no difference to the measured sensitizer enhancement ratio (SER) for MISO. The SER was dose-dependent, being higher doses, but was not different in tumours of 2 or 10 mm diameter. However, when comparing response to X-rays alone, the method of analysis made a very big difference to the conclusions. Regrowth to R + 4.5 mm showed no change in radiosensitivity with tumour size, but regrowth to 4 times the original volume (the most logical endpoint) indicated that large tumours were more sensitive than small. We conclude that regrowth delay may be an inappropriate method for comparing absolute sensitivities of tumours of different sizes. However, for studying the effectiveness of a radiomodifier the constraints of tumour size at irradiation seem to be less severe than previously believed. (author). 8 refs.; 8 figs

  7. Conceptual design studies of experimental and demonstration fusion reactors

    International Nuclear Information System (INIS)

    1978-01-01

    Since 1973 the FINTOR Group has been involved in conceptual design studies of TOKAMAK-type fusion reactors to precede the construction of a prototype power reactor plant. FINTOR-1 was the first conceptual design aimed at investigating the main physics and engineering constraints on a minimum-size (both dimensions and thermal power) tokamak experimental reactor. The required plasma energy confinement time as evaluated by various power balance models was compared with the values resulting from different transport models. For the reference design, an energy confinement time ten times smaller than neoclassical was assumed. This also implied a rather high (thermally stable) working temperature (above 20 keV) for the reactor. Other relevant points of the design were: circular plasma cross section, single-null axisymmetric divertor; lithium breeder, stainless steel structures, helium coolant; modular blanket and shield structure; copper-stabilized, superconducting Nb-Ti toroidal field and divertor coils; vertical field and transformer coils inside the toroidal coils; vacuum-tight containment vessel. Solutions involving air and iron transformer cores were compared. These assumptions led to a minimum size reactor with a thermal power of about 100MW and rather large dimensions (major radius of about 9m) similar to those of full-scale power reactors considered in other conceptual studies. The FINTOR-1 analysis was completed by the end of 1976. In 1977 a conceptual design of a Demonstration Power Reactor Plant (FINTOR-D) was started. In this study the main working assumptions differing from those of FINTOR-1 are: non-circular plasma cross section; plasma confinement compatible with trapped ion instabilities; cold (gas) blanket sufficient for wall protection (no divertor); wall loading between 1-3MW/m 2 and thermal power of a few GW. (author)

  8. Sustaining a Global Social Network: a quasi-experimental study.

    Science.gov (United States)

    Benton, D C; Ferguson, S L

    2017-03-01

    To examine the longer term impact on the social network of participating nurses in the Global Nursing Leadership Institute (GNLI2013) through using differing frequencies of follow-up to assess impact on maintenance of network cohesion. Social network analysis is increasingly been used by nurse researchers, however, studies tend to use single point-in-time descriptive methods. This study utilizes a repeated measures, block group, control-intervention, quasi-experimental design. Twenty-eight nurse leaders, competitively selected through a double-blind peer review process, were allocated to five action learning-based learning groups. Network architecture, measures of cohesion and node degree frequency were all used to assess programme impact. The programme initiated and sustained connections between nurse leaders drawn from a geographically dispersed heterogeneous group. Modest inputs of two to three e-mails over a 6-month period seem sufficient to maintain connectivity as indicated by measures of network density, diameter and path length. Due to the teaching methodology used, the study sample was relatively small and the follow-up data collection took place after a relatively short time. Replication and further cohort data collection would be advantageous. In an era where many policy solutions are being debated and initiated at the global level, action learning leadership development that utilizes new technology follow-up appears to show significant impact and is worthy of wider application. The approach warrants further inquiry and testing as to its longer term effects on nursing's influence on policy formulation and implementation. © 2016 International Council of Nurses.

  9. Experimental and Numerical Study of Twin Underexpanded Impinging Jets

    Institute of Scientific and Technical Information of China (English)

    Minoru Yaga; Minoru Okano; Masumi Tamashiro; Kenyu Oyakawa

    2003-01-01

    In this paper, the dual underexpanded impinging jets are experimentally and numerically studied. The experiments were performed by measuring the unsteady and averaged wall static pressures and by visualizing density fields using schlieren method. Numerical calculations were also conducted by solving unsteady three dimensional compressible Navier-Stokes equations with Baldwin-Lomax turbulence model. The main parameters for the dual jets are the non-dimensional distance between the two nozzle centers H/D covering 1.5, 2.0, the nozzle to plate separation L/D 2.0, 3.0,4.0 and 5.0 and the pressure ratio defined by Po/Pb 1.0~6.0, where D is the diameter of each nozzle exit, Po the stagnation pressure and Pb the back pressure. It is found that the agreement between the experiments and the calculations is good. The fountain flow at the middle of the two jets is observed both in the experiments and the calculation. According to FFT analysis of the experiments for the twin jets,relatively low frequency (up to 5 kHz) is dominant for H/D =1.5, L/D =2.0 and pressure ratio Po/Pb =3.0 and 5.0,which is confirmed by the experiments.

  10. Passing the Baton: An Experimental Study of Shift Handover

    Science.gov (United States)

    Parke, Bonny; Hobbs, Alan; Kanki, Barbara

    2010-01-01

    Shift handovers occur in many safety-critical environments, including aviation maintenance, medicine, air traffic control, and mission control for space shuttle and space station operations. Shift handovers are associated with increased risk of communication failures and human error. In dynamic industries, errors and accidents occur disproportionately after shift handover. Typical shift handovers involve transferring information from an outgoing shift to an incoming shift via written logs, or in some cases, face-to-face briefings. The current study explores the possibility of improving written communication with the support modalities of audio and video recordings, as well as face-to-face briefings. Fifty participants participated in an experimental task which mimicked some of the critical challenges involved in transferring information between shifts in industrial settings. All three support modalities, face-to-face, video, and audio recordings, reduced task errors significantly over written communication alone. The support modality most preferred by participants was face-to-face communication; the least preferred was written communication alone.

  11. Experimental study of liquid drop impact onto a powder surface

    KAUST Repository

    Marston, Jeremy; Thoroddsen, Sigurdur T; Ng, Waikiong; Tan, Reginald

    2010-01-01

    The initial dynamics of liquid drop impact onto powder surfaces is studied experimentally using high-speed photography. For a range of bed packing fractions, φ, liquid physical properties and impact velocities, ui, we observe a variety of phenomena that can be representative of a hydrophobic surface, a rough surface or a porous medium. The solids packing fraction in the bed, 0.38≤φ≤0.65, and the impact Weber number, 3.5≤We=ρDui 2/φ≤750, (where ρ, D and φ are the drop density, diameter and surface tension respectively) are shown to be the critical parameters governing the outcome of an impact. For high packing fractions, φ≳0.5, we show that the observed spreading, rebound and splashing can be broadly characterised in terms of the Weber number while for looser packing fractions, φ≲0.5, we observe powder ejectas and provide a qualitative description of the granule nucleation at the centre of the impact sites. © 2010 Elsevier B.V.

  12. Experimental Study Of Fog Water Harvesting By Stainless Steel Mesh

    Directory of Open Access Journals (Sweden)

    Nikhil R. Pawar

    2017-06-01

    Full Text Available The collection of fog water is a simple and sustainable technology to get hold of fresh water for various purposes. In areas where a substantial amount of fog can be obtained it is feasible to set up a stainless steel as well as black double layer plastic mesh structure for fog water harvesting. The mesh structure is directly exposed to the weather and the fog containing air is pushed through the active mesh surface by the wind. Afterward fog droplets are deposited on the active mesh area which combines to form superior droplets and run down into a gutter to storage by gravity. Fog water harvesting rates show a discrepancy from site to site. The scope of this experimental work is to review fog collection at SCOE Pune campus and to examine factors of success. This study is to synthesize the understanding of fog water harvesting in the institutional era and to analyze its benefits and boundaries for future development. The rate of fog water harvesting depends on the science of fog physics chemistry and its starring role in the hydrological cycle. This technology runs on zero energy and zeroes pollution level with cost of the benefit. The collected or treated clear water mainly could be used for different purposes as per requirement. For further development this technology public as well as government participation is needed.

  13. Experimental study on the dispersion properties of cusptron structure

    International Nuclear Information System (INIS)

    Choe, J.Y.; Crosby, H.; Jablon, D.G.; Krall, A.D.; Namkung, W.

    1984-01-01

    One of the promising devices that generates high frequency microwaves is the cusptron, where the fast rotating electron beam interacts with the high muthal (iota>1) waveguide mode, thereby producing multiples of the cyclotron frequency (iotaω/sub c/). In order to encourage the chosen azimuthal perturbation, it is necessary to structure the wall in a magnetron-like shape. In particular, the authors consider the structure where the outer wall is radially cut out to make multiple vane-like resonators. With these interruptions, it obvious that there exist strong couplings among the muthal space harmonics, iota n in the cusptron device. The mode is characterized by the axial wave number, k, the primary azimuthal mode number iota, which indicates the phase difference between adjacent segments, and whether it is TE or TM. Recently, a rigorous numerical method has been devised to determine the cusptron structure. This method uses the orthonormal mode expansions both in the interaction space and the resonators to assure the point-by-point match of the fields. The method also finds the distribution of the harmonics iota n as well, that serves as a signature of the particular mode. In the present study, the authors experimentally investigate the dispersion characteristics of the cusptron, and compare the results with the theory

  14. Augmented reality in bone tumour resection: An experimental study.

    Science.gov (United States)

    Cho, H S; Park, Y K; Gupta, S; Yoon, C; Han, I; Kim, H-S; Choi, H; Hong, J

    2017-03-01

    We evaluated the accuracy of augmented reality (AR)-based navigation assistance through simulation of bone tumours in a pig femur model. We developed an AR-based navigation system for bone tumour resection, which could be used on a tablet PC. To simulate a bone tumour in the pig femur, a cortical window was made in the diaphysis and bone cement was inserted. A total of 133 pig femurs were used and tumour resection was simulated with AR-assisted resection (164 resection in 82 femurs, half by an orthropaedic oncology expert and half by an orthopaedic resident) and resection with the conventional method (82 resection in 41 femurs). In the conventional group, resection was performed after measuring the distance from the edge of the condyle to the expected resection margin with a ruler as per routine clinical practice. The mean error of 164 resections in 82 femurs in the AR group was 1.71 mm (0 to 6). The mean error of 82 resections in 41 femurs in the conventional resection group was 2.64 mm (0 to 11) (p Augmented reality in bone tumour resection: An experimental study. Bone Joint Res 2017;6:137-143. © 2017 Cho et al.

  15. Experimental Study of Goaf Filling Materials Based on Red Mud

    Science.gov (United States)

    Mu, Mangen; Gao, Xiaozhen; Guo, Taoming; Hu, Xinping

    2018-01-01

    Red mud as soild waste is difficult to treatment. Goaf filling materials can make a large use of red mud. By the experimental study,we find that the red mud, fly ash, ground slag and desulfida-tion gypsum can be used to make goaf filling materials based on the principle of alkali excitation and metalion stability.Through the control variable method, we find that the optimal proportion of goaf filling materials based on red mud is red mud 55%, fly ash 30%, cement 7.5%, fly ash 2.5%, desulfurization gypsum 5%, admixture 1%, and water solid ratio=1:1.2.The 28days final material strength was 2.0 MPa,which achives the technical specification requirements.Through the test of SEM, XRD and IR, it is indicated that the strength formation of goaf filling material based on red mud is from the unformed linking hydration products of amorphous alkali excitation system. With curing time from 3 to 7 days, the unformed linking hydration products grown a lot of vitreous hydration products. When hydration reaction basicly finished after 28 days, the hydration products have developed into a large volume of massive vitreous with an extremely dense structure. The Ca2SiO3 mineral phase is significantly reduced, which is participate in hydration reactions. The decrease of Ca2SiO3 indicates that the Si-O bond in the system have been ruptured and reorganized.

  16. Experimental study of elliptical jet from sub to supercritical conditions

    Energy Technology Data Exchange (ETDEWEB)

    Muthukumaran, C. K.; Vaidyanathan, Aravind, E-mail: aravind7@iist.ac.in [Department of Aerospace Engineering, Indian Institute of Space Science and Technology, Trivandrum, Kerala 695547 (India)

    2014-04-15

    The jet mixing at supercritical conditions involves fluid dynamics as well as thermodynamic phenomena. All the jet mixing studies at critical conditions to the present date have focused only on axisymmetric jets. When the liquid jet is injected into supercritical environment, the thermodynamic transition could be well understood by considering one of the important fluid properties such as surface tension since it decides the existence of distinct boundary between the liquid and gaseous phase. It is well known that an elliptical liquid jet undergoes axis-switching phenomena under atmospheric conditions due to the presence of surface tension. The experimental investigations were carried out with low speed elliptical jet under supercritical condition. Investigation of the binary component system with fluoroketone jet and N{sub 2} gas as environment shows that the surface tension force dominates for a large downstream distance, indicating delayed thermodynamic transition. The increase in pressure to critical state at supercritical temperature is found to expedite the thermodynamic transition. The ligament like structures has been observed rather than droplets for supercritical pressures. However, for the single component system with fluoroketone jet and fluoroketone environment shows that the jet disintegrates into droplets as it is subjected to the chamber conditions even for the subcritical pressures and no axis switching phenomenon is observed. For a single component system, as the pressure is increased to critical state, the liquid jet exhibits gas-gas like mixing behavior and that too without exhibiting axis-switching behavior.

  17. Experimental study on a parabolic concentrator assisted solar desalting system

    International Nuclear Information System (INIS)

    Arunkumar, T.; Denkenberger, David; Velraj, R.; Sathyamurthy, Ravishankar; Tanaka, Hiroshi; Vinothkumar, K.

    2015-01-01

    Highlights: • We optimized the augmentation of condense by enhanced desalination methodology. • Parabolic concentrator has been integrated with solar distillation systems. • We measured ambient together with solar radiation intensity. - Abstract: This paper presents a modification of parabolic concentrator (PC) – solar still with continuous water circulation using a storage tank to enhance the productivity. Four modes of operation were studied experimentally: (i) PC-solar still without top cover cooling; (ii) PC-solar still with top cover cooling, PC-solar still integrated with phase change material (PCM) without top cover cooling and PC-solar still integrated PCM with cooling. The experiments were carried out for the cooling water flow rates of 40 ml/min; 50 ml/min, 60 ml/min, 80 ml/min and 100 ml/min. Diurnal variations of water temperature (T_w), ambient air temperature (T_a), top cover temperature (T_o_c) and production rate are measured with frequent time intervals. Water cooling was not cost effective, but adding PCM was.

  18. Attentional bias in snus users: an experimental study.

    Directory of Open Access Journals (Sweden)

    Rune Aune Mentzoni

    Full Text Available The use of nicotine in the form of "snus" is substantial and increasing in some geographic areas, in particular among young people. It has previously been suggested that addictions may operate through a mechanism of attentional bias, in which stimuli representative of the dependent substance increase in salience, thus increasing the addictive behavior. However, this hypothesis has not been tested for the case of snus. The current experiment used a modified Stroop task and a dot-probe task to investigate whether 40 snus users show an attentional bias towards snus-relevant stimuli, compared to 40 non-snus users. There were no significant differences between the two groups on reaction times or accuracy on either Stroop or dot-probe task, thus failing to show an attentional bias towards snus-relevant stimuli for snus users. This could imply that other mechanisms may contribute to maintenance of snus use than for other addictions. However, this is the first experimental study investigating attentional bias in snus users, and more research is warranted.

  19. Experimental study of two-phase natural circulation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Wanderley Freitas; Su, Jian, E-mail: wlemos@lasme.coppe.ufrj.br, E-mail: sujian@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Faccini, Jose Luiz Horacio, E-mail: faccini@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), RIo de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental

    2012-07-01

    This paper reports an experimental study on the behavior of fluid flow in natural circulation under single-and two-phase flow conditions. The natural circulation circuit was designed based on concepts of similarity and scale in proportion to the actual operating conditions of a nuclear reactor. This test equipment has similar performance to the passive system for removal of residual heat presents in Advanced Pressurized Water Reactors (A PWR). The experiment was carried out by supplying water to primary and secondary circuits, as well as electrical power resistors installed inside the heater. Power controller has available to adjust the values for supply of electrical power resistors, in order to simulate conditions of decay of power from the nuclear reactor in steady state. Data acquisition system allows the measurement and control of the temperature at different points by means of thermocouples installed at several points along the circuit. The behavior of the phenomenon of natural circulation was monitored by a software with graphical interface, showing the evolution of temperature measurement points and the results stored in digital format spreadsheets. Besides, the natural circulation flow rate was measured by a flowmeter installed on the hot leg. A flow visualization technique was used the for identifying vertical flow regimes of two-phase natural circulation. Finally, the Reynolds Number was calculated for the establishment of a friction factor correlation dependent on the scale geometrical length, height and diameter of the pipe. (author)

  20. Thermochemical study of cyanopyrazines: Experimental and theoretical approaches

    International Nuclear Information System (INIS)

    Miranda, Margarida S.; Morais, Victor M.F.; Matos, M. Agostinha R.

    2006-01-01

    The standard (p - bar =0.1MPa) molar energy of combustion, at T=298.15K, of crystalline 2,3-dicyanopyrazine was measured by static bomb calorimetry, in oxygen atmosphere. The standard molar enthalpy of sublimation, at T=298.15K, was obtained by Calvet Microcalorimetry, allowing the calculation of the standard molar enthalpy of formation of the compound, in the gas phase, at T=298.15K: Δ f H m - bar (g)=(518.7+/-3.4)kJ.mol -1 . In addition, the geometries of all cyanopyrazines were obtained using density functional theory with the B3LYP functional and two basis sets: 6-31G* and 6-311G**. These calculations were then used for a better understanding of the relation between structure and energetics of the cyanopyrazine systems. These calculations also reproduce measured standard molar enthalpies of formation with some accuracy and do provide estimates of this thermochemical parameter for those compounds that could not be studied experimentally, namely the tri- and tetracyanopyrazines: the strong electron withdrawing cyano group on the pyrazine ring makes cyanopyrazines highly destabilized compounds

  1. Experimental study of ERT monitoring ability to measure solute dispersion.

    Science.gov (United States)

    Lekmine, Grégory; Pessel, Marc; Auradou, Harold

    2012-01-01

    This paper reports experimental measurements performed to test the ability of electrical resistivity tomography (ERT) imaging to provide quantitative information about transport parameters in porous media such as the dispersivity α, the mixing front velocity u, and the retardation factor R(f) associated with the sorption or trapping of the tracers in the pore structure. The flow experiments are performed in a homogeneous porous column placed between two vertical set of electrodes. Ionic and dyed tracers are injected from the bottom of the porous media over its full width. Under such condition, the mixing front is homogeneous in the transverse direction and shows an S-shape variation in the flow direction. The transport parameters are inferred from the variation of the concentration curves and are compared with data obtained from video analysis of the dyed tracer front. The variations of the transport parameters obtained from an inversion performed by the Gauss-Newton method applied on smoothness-constrained least-squares are studied in detail. While u and R(f) show a relatively small dependence on the inversion procedure, α is strongly dependent on the choice of the inversion parameters. Comparison with the video observations allows for the optimization of the parameters; these parameters are found to be robust with respect to changes in the flow condition and conductivity contrast. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.

  2. Experimental study and modelization of a propane storage tank depressurization

    International Nuclear Information System (INIS)

    Veneau, Tania

    1995-01-01

    The risks associated with the fast depressurization of propane storage tanks reveals the importance of the 'source term' determination. This term is directly linked, among others, to the characteristics of the jet developed downstream of the breach. The first aim of this work was to provide an original data bank concerning drop velocity and diameter distributions in a propane jet. For this purpose, a phase Doppler anemometer bas been implemented on an experimental set-up. Propane blowdowns have been performed with different breach sizes and several initial pressures in the storage tank. Drop diameter and velocity distributions have been investigated at different locations in the jet zone. These measurements exhibited the fragmentation and vaporisation trends in the jet. The second aim of this work concerned the 'source term'. lt required to study the coupling between the fluid behaviour inside the tank and the flow through the breach. This model took into account the phase exchange when flashing occurred in the tank. The flow at the breach was described with an homogeneous relaxation model. This coupled modelization has been successfully and exhaustively validated. lt originality lies on the application to propane flows. (author) [fr

  3. Experimental study on bearing preload optimum of machine tool spindle

    International Nuclear Information System (INIS)

    Xu Tao; Xu Guanghua; Zhang Qin; Hua Cheng; Zhang Hu; Jiang Kuosheng

    2012-01-01

    An experimental study is conducted to investigate the possibility and the effect of temperature rise and vibration level of bearing by adjusting axial preloads and radial loads in spindle bearing test rig. The shaft of the test rig is driven by a motorized high speed spindle at the range of 0∼20000 rpm. The axial preloads and radial loads on bearings are controlled by using hydraulic pressure which can be adjusted automatically. Temperature rise and radial vibration of test bearings are measured by thermocouples and Polytec portable laser vibrometer PDV100. Experiment shows that the temperature rise of bearings is nonlinear varying with the increase of radial loads, but temperature rise almost increases linearly with the increase of axial preload and rotating speed. In this paper, an alternate axial preload is used for bearings. When the rotating speed passes through the critical speed of the shaft, axial preload of bearings will have a remarkable effect. The low preload could reduce bearing vibration and temperature rise for bearings as well. At the others speed, the high preload could improve the vibration performance of high speed spindle and the bearing temperature was lower than that of the constant pressure preload spindle.

  4. Design study of toroidal magnets for tokamak experimental power reactors

    International Nuclear Information System (INIS)

    Stekly, Z.J.J.; Lucas, E.J.

    1976-12-01

    This report contains the results of a six-month study of superconducting toroidal field coils for a Tokamak Experimental Power Reactor to be built in the late 1980s. The designs are for 8 T and 12 T maximum magnetic field at the superconducting winding. At each field level two main concepts were generated; one in which each of the 16 coils comprising the system has an individual vacuum vessel and the other in which all the coils are contained in a single vacuum vessel. The coils have a D shape and have openings of 11.25 m x 7.5 m for the 8 T coils and 10.2 m x 6.8 m for the 12 T coils. All the designs utilize rectangular cabled conductor made from copper stabilized Niobium Titanium composite which operates at 4.2 K for the 8 T design and at 2.5 K for the 12 T design. Manufacturing procedures, processes and schedule estimates are also discussed

  5. Experimental study on moonpool resonance of offshore floating structure

    Directory of Open Access Journals (Sweden)

    Seung-Ho Yang

    2013-06-01

    Full Text Available Offshore floating structures have so-called moonpool in the centre area for the purpose of drilling, installation of subsea structures, recovery of Remotely-Operated Vehicle (ROV and divers. However, this vertical opening has an effect on the operating performance of floating offshore structure in the vicinity of moonpool resonance frequency; piston mode and sloshing mode. Experimental study based on model test was carried out. Moonpool resonance of floating offshore structure on fixed condition and motion free condition were investigated. And, the effect of cofferdam which is representative inner structure inside moonpool was examined. Model test results showed that Molin's theoretical formula can predict moonpool resonance on fixed condition quite accurately. However, motion free condition has higher resonance frequency when it is compared with that of motion fixed. The installation of cofferdam moves resonance frequency to higher region and also generates secondary resonance at lower frequency. Furthermore, it was found that cofferdam was the cause of generating waves in the longitudinal direction when the vessel was in beam sea.

  6. Experimental and computational studies on a gasifier based stove

    International Nuclear Information System (INIS)

    Varunkumar, S.; Rajan, N.K.S.; Mukunda, H.S.

    2012-01-01

    Highlights: ► A simple method to calculate the fraction of HHC was devised. ► η g for stove is same as that of a downdraft gasifier. ► Gas from stove contains 5.5% of CH 4 equivalent of HHC. ► Effect of vessel size on utilization efficiency brought out clearly. ► Contribution of radiative heat transfer from char bed to efficiency is 6%. - Abstract: The work reported here is concerned with a detailed thermochemical evaluation of the flaming mode behaviour of a gasifier based stove. Determination of the gas composition over the fuel bed, surface and gas temperatures in the gasification process constitute principal experimental features. A simple atomic balance for the gasification reaction combined with the gas composition from the experiments is used to determine the CH 4 equivalent of higher hydrocarbons and the gasification efficiency (η g ). The components of utilization efficiency, namely, gasification–combustion and heat transfer are explored. Reactive flow computational studies using the measured gas composition over the fuel bed are used to simulate the thermochemical flow field and heat transfer to the vessel; hither-to-ignored vessel size effects in the extraction of heat from the stove are established clearly. The overall flaming mode efficiency of the stove is 50–54%; the convective and radiative components of heat transfer are established to be 45–47 and 5–7% respectively. The efficiency estimates from reacting computational fluid dynamics (RCFD) compare well with experiments.

  7. Theoretical and experimental studies of a magnetically actuated valveless micropump

    International Nuclear Information System (INIS)

    Ashouri, Majid; Shafii, Mohammad Behshad; Moosavi, Ali

    2017-01-01

    This paper presents the prototype design, fabrication, and characterization of a magnetically actuated micropump. The pump body consists of three nozzle/diffuser elements and two pumping chambers connected to the ends of a flat-wall pumping cylinder. A cylindrical permanent magnet placed inside the pumping cylinder acts as a piston which reciprocates by using an external magnetic actuator driven by a motor. The magnetic piston is covered by a ferrofluid to provide self-sealing capability. A prototype composed of three bonded layers of polymethyl-methacrylate (PMMA) has been fabricated. Water has been successfully pumped at pressures of up to 750 Pa and flow rates of up to 700 µ l min −1 while working at the piston actuation frequency of 4 and 5 Hz, respectively. 3D numerical simulations are also carried out to study the performance of the pump. The best experimental and numerical volumetric efficiency of the pump are about 7 and 8%, respectively, at the piston speed of 0.03 m s −1 . The contactless external actuation feature of the design enables integration of the pump with other PMMA-based microfluidic systems with low cost and disposability. (paper)

  8. Experimental study and modelling of iron ore reduction by hydrogen

    International Nuclear Information System (INIS)

    Wagner, D.

    2008-01-01

    In an effort to find new ways to drastically reduce the CO 2 emissions from the steel industry (ULCOS project), the reduction of iron ore by pure hydrogen in a shaft furnace was investigated. The work consisted of literature, experimental, and modelling studies. The chemical reaction and its kinetics were analysed on the basis of thermogravimetric experiments and physicochemical characterizations of partially reduced samples. A specific kinetic model was designed, which simulates the successive reactions, the different steps of mass transport, and possible iron sintering, at the particle scale. Finally, a 2-dimensional numerical model of a shaft furnace was developed. It depicts the variation of the solid and gas temperatures and compositions throughout the reactor. One original feature of the model is using the law of additive characteristic times for calculating the reaction rates. This allowed us to handle both the particle and the reactor scale, while keeping reasonable calculation time. From the simulation results, the influence of the process parameters was assessed. Optimal operating conditions were concluded, which reveal the efficiency of the hydrogen process. (author)

  9. An experimental study on the radiation hazard of the mandible

    International Nuclear Information System (INIS)

    Sakurai, Tohru

    1987-01-01

    The purpose of this study is to investigate the influence of the tooth extraction after irradiation to the mandible experimentally. The following results were obtained. 1. In a group whose teeth were extracted immediately after irradiation, healing of the extraction wound was delayed. However, severe radiation hazard was not recognized macroscopically. 2. In a group whose teeth were extracted after 2 weeks following irradiation, radiation osteomyelitis was recognized macroscopically. All of these cases showed disturbances of healing of the extraction wound. 3. The early radiographical finding on the mandible, in which the teeth had been extracted after irradiation, was osteoporosis and it was accelerated by infection. 4. Bone resorption caused by osteoclast was observed microscopically in a group whose teeth were extracted after irradiation. Osteoporotic bone resorption was accelerated by infection, and was decreased by subsidings of infection and blood vessel hazard. 5. Sequestration was one of the results of radiation osteomyelitis, which was caused by the disturbance of blood circulation due to periosteum detachment. Sequestrum was caused by invasion of the healthy gingiva. 6. Though healing of the extraction wound was delayed by irradiation, new bone was formed in the alveolar socket if the blood clot occupied the alveolar socket. 7. Radiation hazard of the mandible became more severe when the mandible was accompanied by infection. (J.P.N.)

  10. Generating physical symptoms from visual cues: An experimental study.

    Science.gov (United States)

    Ogden, Jane; Zoukas, Serafim

    2009-12-01

    This experimental study explored whether the physical symptoms of cold, pain and itchiness could be generated by visual cues, whether they varied in the ease with which they could be generated and whether they were related to negative affect. Participants were randomly allocated by group to watch one of three videos relating to cold (e.g. ice, snow, wind), pain (e.g. sporting injuries, tattoos) or itchiness (e.g. head lice, scratching). They then rated their self-reported symptoms of cold, pain and itchiness as well as their negative affect (depression and anxiety). The researcher recorded their observed behaviour relating to these symptoms. The results showed that the interventions were successful and that all three symptoms could be generated by the visual cues in terms of both self-report and observed behaviour. In addition, the pain video generated higher levels of anxiety and depression than the other two videos. Further, the degree of itchiness was related to the degree of anxiety. This symptom onset process also showed variability between symptoms with self-reported cold symptoms being greater than either pain or itchy symptoms. The results show that physical symptoms can be generated by visual cues indicating that psychological factors are not only involved in symptom perception but also in symptom onset.

  11. Young adult smoking in peer groups: an experimental observational study.

    Science.gov (United States)

    Harakeh, Zeena; Vollebergh, Wilma A M

    2013-03-01

    The aim of this experimental observational study is to examine whether, in a group setting (same-sex triads), passive peer influence (imitation) in the context of homogeneous and heterogeneous (contradictory) behavior of peer models affects young adults' smoking behavior. An experiment was conducted among 48 daily-smoking college and university students aged 17-25. Participants had to complete a 30-min music task with two same-sex confederates. We tested the following three conditions: (a) neither of the confederates is smoking, (b) one confederate is smoking and the other is not, and (c) both confederates are smoking. The primary outcome tested was the total number of cigarettes smoked during the task. Students in the condition with two smoking peer models and in the condition with one smoking peer model and one nonsmoking peer model smoked significantly more cigarettes than those in the condition with two nonsmoking peer models. However, results for the condition with two smoking peer models did not differ significantly from the condition with one smoking peer model and one nonsmoking peer model. Our findings show that in a group setting, the impact of the homogeneity of smoking peers on young adults' smoking behavior is not greater than the impact of the heterogeneity of smoking and nonsmoking peers. This would suggest that the smoking peer in the group has a greater impact on the daily-smoking young adult, thus reducing or even eliminating the protective effect of the nonsmoking peer model.

  12. Experimental study on titanium wire drawing with ultrasonic vibration.

    Science.gov (United States)

    Liu, Shen; Shan, Xiaobiao; Guo, Kai; Yang, Yuancai; Xie, Tao

    2018-02-01

    Titanium and its alloys have been widely used in aerospace and biomedical industries, however, they are classified as difficult-to-machine materials. In this paper, ultrasonic vibration is imposed on the die to overcome the difficulties during conventional titanium wire drawing processes at the room temperature. Numerical simulations were performed to investigate the variation of axial stress within the contacting region and study the change of the drawing stress with several factors in terms of the longitudinal amplitude and frequency of the applied ultrasonic vibration, the diameter reduction ratio, and the drawing force. An experimental testing equipment was established to measure the drawing torque and rotational velocity of the coiler drum during the wire drawing process. The result indicates the drawing force increases with the growth of the drawing velocity and the reduction ratio, whether with or without vibrations. Application of either form of ultrasonic vibrations contributes to the further decrease of the drawing force, especially the longitudinal vibration with larger amplitude. SEM was employed to detect the surface morphology of the processed wires drawn under the three circumstances. The surface quality of the drawn wires with ultrasonic vibrations was apparently improved compared with those using conventional method. In addition, the longitudinal and torsional composite vibration was more effective for surface quality improvement than pure longitudinal vibration, however, at the cost of weakened drawing force reduction effect. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. SPS ionosphere/microwave beam interactions: Arecibo experimental studies

    International Nuclear Information System (INIS)

    Duncan, L.M.

    1980-10-01

    The purpose of this program is to determine the environmental impacts associated with the operation of the proposed SPS microwave power transmission system. It is expected that thermal effects will provide the dominant force driving the nonlinear ionosphere/microwave beam interactions. Collisional damping of radio waves, producing ohmic heating of the ionospheric plasma, depends inversely on the square of the radio wave frequency. Therefore, equivalent heating and equivalent thermal forces can be generated at lower radiated power densities by using lower radio wave frequencies. This principle is fundamental to a large part of the experimental program. An understanding of the physics of the specific interactions excited by the SPS microwave beam is also an important part of the assessment program. This program is designed to determine instability thresholds, the growth rates and spatial extent of the resultant ionospheric disturbances, and the frequency and power dependences of the interactions. How these interactions are affected by variations in the natural ionospheric conditions, how different instabilities occurring simultaneously may affect each other, and how distinct microwave beams might mutually interact are studied. Status of the program is described

  14. Experimental studies of plasma wake-field acceleration and focusing

    International Nuclear Information System (INIS)

    Rosenzweig, J.B.; Cole, B.; Ho, C.; Argonne National Lab., IL

    1989-01-01

    More than four years after the initial proposal of the Plasma Wake-field Accelerator (PWFA), it continues to be the object of much investigation, due to the promise of the ultra-high accelerating gradients that can exist in relativistic plasma waves driven in the wake of charged particle beams. These large amplitude plasma wake-fields are of interest in the laboratory, both for the wealth of basic nonlinear plasma wave phenomena which can be studied, as well as for the applications of acceleration of focusing of electrons and positrons in future linear colliders. Plasma wake-field waves are also of importance in nature, due to their possible role in direct cosmic ray acceleration. The purpose of the present work is to review the recent experimental advances made in PWFA research at Argonne National Laboratory, in which many interesting beam and plasma phenomena have been observed. Emphasis is given to discussion of the nonlinear aspects of the PWFA beam-plasma interaction. 29 refs., 13 figs

  15. Design and experimental study of a novel giant magnetostrictive actuator

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Guangming, E-mail: yy0youxia@163.com [Vehicle and Electrical Engineering Department, Ordnance Engineering College, Shijiazhuang, 050003 China (China); Zhang, Peilin; He, Zhongbo; Li, Dongwei; Huang, Yingjie [Vehicle and Electrical Engineering Department, Ordnance Engineering College, Shijiazhuang, 050003 China (China); Xie, Wenqiang [Cadre Rotational Training Brigade, Ordnance Engineering College, Shijiazhuang, 050003 China (China)

    2016-12-15

    Giant magnetostrictive actuator has been widely used in precise driving occasions for its excellent performance. However, in driving a switching valve, especially the ball-valve in an electronic controlled injector, the actuator can’t exhibit its good performance for limits in output displacement and responding speed. A novel giant magnetostrictive actuator, which can reach its maximum displacement for being exerted with no bias magnetic field, is designed in this paper. Simultaneously, elongating of the giant magetostrictive material is converted to shortening of the actuator's axial dimension with the help of an output rod in “T” type. Furthermore, to save responding time, the driving voltage with high opening voltage while low holding voltage is designed. Responding time and output displacement are studied experimentally with the help of a measuring system. From measured results, designed driving voltage can improve the responding speed of actuator displacement quite effectively. And, giant magnetostrictive actuator can output various steady-state displacements to reach more driving effects. - Highlights: • GMA with zero bias magnetic field can reach maximum displacement in one direction. • Driving wave with high opening voltage can promote GMA's responding speed. • Higher opening voltage is exerted, less rise time is reached. • Continuous displacements from 0 to maximum value can be achieved by GMA.

  16. Experimental study of the fast wave propagation in TFR

    International Nuclear Information System (INIS)

    1981-02-01

    Several experiments (PLT, DIVA, ERASMUS, TFR) have shown that the heating mechanism of ICRF is dominated in Tokamaks by the presence of the ion-ion hybrid layer. The first experimental evidence of this effect came from propagation studies: a very strong damping was observed on magnetic probes since the hybrid layer was inside the plasma. Comparison with simple models which do not take into account boundary conditions have been undertaken. Recently a new theoretical model has been developped. Based on a plane, inhomogeneous, bounded plasma, it shows that the radial structure of the fast wave and hence the loading impedance of the launching coil depends on the position of the hybrid layer with respect to the plasma boundaries. This result is obtained by solving the wave equation, in the cold plasma approximation. We present here, a serie of experiments, performed in TFR. It confirms the validity of that model underlining thus the importance of radial eigenmodes, when the wave conversion layer is inside the plasma

  17. Experimental study of the Ag-Sn-In phase diagram

    International Nuclear Information System (INIS)

    Vassilev, Gueorgui P.; Dobrev, Evgueni S.; Tedenac, Jean-Claude

    2005-01-01

    Combined metallographic, differential scanning calorimetry, X-ray and scanning electron microscopy studies have been performed using 27 ternary alloys. The microhardness of the α(Ag), ε(Ag 3 Sn) and ζ(Ag 4 Sn,Ag 3 In) phases has been measured. The ternary extension of the phase φ(Ag x In y Sn z , where x ∼ 0.36, y ∼ 0.61, z ∼ 0.03) has been revealed in some specimens, although the binary compound (AgIn 2 ) melts at 166 deg. C. This finding is attributed to the limited cooling rate. The solubility ranges of the solid solution and the intermetallic phases have been determined. The tin and the indium show approximately equal mutual solubility (around 2 at.%) in the ternary extensions of their Ag-Sn or Ag-In phases. The experimental data have been compared with a calculated isothermal section at 280 deg. C and with a vertical section at 2.5 at.% Ag. The thermal analyses have confirmed, in general, the temperatures of the invariant reactions in the Ag-Sn-In system as calculated by literature data

  18. Pressure swing adsorption: experimental study of an equilibrium theory

    Energy Technology Data Exchange (ETDEWEB)

    Kayser, J C; Knaebel, K S

    1986-01-01

    A theoretical model of pressure swing adsorption (PSA) processes that is based on local, linear equilibrium of a binary gas mixture with an adsorbent was experimentally tested under conditions supportive of the inherent assumptions and constraints. The components studied were nitrogen, oxygen and argon with 5A zeolite molecular sieve, at temperatures from 20 to 60/sup 0/C. Simple breakthrough experiments were analyzed to predict the slopes of the isotherms within 5.4% (mean absolute error) of actual equilibrium values. In two-bed PSA experiments at pressure ratios from 6.5 to 840, the recoveries of the light component (oxygen and argon) were within 7.1% (mean absolute error) of those predicted by theory. Typically, the feed rate to the process was about 2751 (STP)/kg h, based on the total mass of adsorbent. The light-component product purity averaged 99.6% (based on volume) and was never less than 99.2%, while theory predicts complete separation is possible. The results support the validity of the theoretical model for the conditions of the experiments.

  19. Experimental study on behavior of steel channel strengthened with CFRP

    Directory of Open Access Journals (Sweden)

    Tang Hongyuan

    2017-11-01

    Full Text Available This paper describes the behaviour of axially loaded long and eccentrically loaded short thin-walled steel channels, strengthened with transversely bonded carbon fibre reinforced polymer (CFRP sheets. Seven long members, each 1400 mm long, and seven short members, each 750mmlong, were tested. The main parameters were the number of CFRP plies (one or two and the clear spacing between the CFRP strips (50, 100 or 150 mm. The effect of CFRP sheet layer and clear spacing was studied. All the ultimate load capacity of the reinforced members was improved in different extent. A maximum strength gain of 9.13% was achieved for long members with two CFRP layers and 50 mm spacing of CFRP strips. The experimental results show that the global buckling happens to all the long specimens. For short members, the maximum strength gain of 12.1% was achieved with two CFRP layers and 50 mm spacing of CFRP strips. With the exception of the most heavily reinforced (2 plies at 50 and 100 mm, local buckling was observed prior to global buckling for short members, which was completely opposite of the control specimens. Meanwhile, when the clear spacing of CFRP strips is greater than theweb height of steel channel, the transversely bonded CFRP does not have a significant improvement in buckling load capacity of the short- and long-channel components. While the clear spacing is less than the web height, the more number of CFRP layer, the more enhancement of buckling load capacity.

  20. Conceptual design study of fusion experimental reactor (FER)

    International Nuclear Information System (INIS)

    1986-11-01

    Since 1980 the design study has been conducted at JAERI for the Fusion Experimental Reactor (FER) which has been proposed to be the next machine to JT-60 in the Japanese long term program of fusion reactor development. During two years from 1984 to 1985 FER concept was reviewed and redesigned. This report is the summary of the results obtained in the review and redesign activities in 1984 and 85. In the first year FER concept was discussed again and its frame work was reestablished. According to the new frame work the major reactor components of FER were designed. In the second year the whole plant system design including plant layout plan was conducted as well as the more detailed design analysis of the reactor conponents. The newly established frame for FER design is as follows: 1) Plasma : Self-ignition. 2) Operation scenario : Quasi-steady state operation with long burn pulse. 3) Neutron fluence on the first wall : 0.3 MWY/M 2 . 4) Blanket : Non-tritium breeding blanket with test modules for breeding blanket development. 5) Magnets : Superconducting Magnets. (author)