WorldWideScience

Sample records for previous field studies

  1. Rapid mineralisation of the herbicide isoproturon in soil from a previously treated Danish agricultural field.

    Science.gov (United States)

    Sørensen, Sebastian R; Aamand, Jens

    2003-10-01

    Mineralisation of the phenylurea herbicide isoproturon (3-(4-isopropylphenyl)-1,1-dimethylurea) and two of its known metabolites, 3-(4-isopropylphenyl)-1-methylurea (monodesmethyl-isoproturon) and 4-isopropylaniline, was studied in Danish agricultural soils with or without previous exposure to isoproturon. A potential for rapid mineralisation of isoproturon and the two metabolites was present in soils sampled from three plots within an agricultural field previously treated regularly with the herbicide, with 34-45%, 51-58% and 33-36% of the added [phenyl-U-14C]isoproturon, [phenyl-U-14C]monodesmethyl-isoproturon and [phenyl-U-14C]4-isopropylaniline metabolised to [14C]carbon dioxide within 30 days at 20 degrees C. In contrast, such extensive mineralisation of these three compounds was not observed within this period in soils sampled from two other agricultural fields without previous treatment with isoproturon. The mineralisation patterns indicated growth-linked metabolism of the three compounds in the previously exposed soils, and doubling times for [14C]carbon dioxide production ranged from 1.6 to 3.2, 1.0 to 2.1 and 1.3 to 1.7 days for isoproturon, monodesmethyl-isoproturon and 4-isopropylaniline, respectively. The ability to mineralise [phenyl-U-14C]isoproturon to [14C]carbon dioxide was successfully sub-cultured to a fresh mineral medium which provided isoproturon as sole source of carbon and nitrogen. One of the soils sampled from an agricultural field not previously treated with isoproturon showed accelerated mineralisation of [phenyl-U-14C]4-isopropylaniline toward the end of the experiment, with a doubling time for [14C]carbon dioxide production of 7.4days. This study indicates that the occurrence of rapid mineralisation of the phenyl ring of isoproturon to carbon dioxide is related to previous exposure to the herbicide, which suggests that microbial adaptation upon repeated isoproturon use may occur within agricultural fields.

  2. Rhabdomyosarcoma Arising in a Previously Irradiated Field: An Analysis of 43 Patients

    Energy Technology Data Exchange (ETDEWEB)

    Dang, Nguyen D. [Department of Radiation Oncology, Baylor College of Medicine, Houston, Texas (United States); Teh, Bin S. [Department of Radiation Oncology, The Methodist Hospital and Methodist Hospital Research Institute, Houston, Texas (United States); Paulino, Arnold C., E-mail: apaulino@tmhs.org [Department of Radiation Oncology, The Methodist Hospital and Methodist Hospital Research Institute, Houston, Texas (United States)

    2013-03-01

    Patients with soft tissue sarcomas that arise from previously irradiated fields have traditionally been reported to have a poor prognosis. In this report, we examined the characteristics and outcomes of patients who developed a rhabdomyosarcoma in a previously irradiated field (RMS-RIF); we hypothesize that these patients should have a better outcome compared to other postradiation soft tissue sarcomas as these tumors are chemosensitive and radiosensitive. A PubMed search of the literature from 1961-2010 yielded 33 studies with data for patients with RMS-RIF. The study included 43 patients with a median age of 6.5 years at the time of radiation therapy (RT) for the initial tumor. The median RT dose was 48 Gy. The median latency period, the time from RT to development of RMS-RIF, was 8 years. The 3-year overall survival for RMS-RIF was 42%. The 3-year overall survival was 66% for patients receiving chemotherapy and local treatment (surgery and/or RT) compared to 29% for those who had systemic treatment only or local treatment only (P=.049). Other factors associated with increased 3-year overall survival included retinoblastoma initial diagnosis (P<.001), age ≤18 years at diagnosis of RMS-RIF (P=.003), favorable site (P=.008), and stage 1 disease (P=.002). Age at time of RMS-RIF, retinoblastoma initial tumor, favorable site, stage 1 disease, and use of both systemic and local treatment were found to be favorable prognostic factors for 3-year overall survival.

  3. Validation of SWAT+ at field level and comparison with previous SWAT models in simulating hydrologic quantity

    Science.gov (United States)

    GAO, J.; White, M. J.; Bieger, K.; Yen, H.; Arnold, J. G.

    2017-12-01

    Over the past 20 years, the Soil and Water Assessment Tool (SWAT) has been adopted by many researches to assess water quantity and quality in watersheds around the world. As the demand increases in facilitating model support, maintenance, and future development, the SWAT source code and data have undergone major modifications over the past few years. To make the model more flexible in terms of interactions of spatial units and processes occurring in watersheds, a completely revised version of SWAT (SWAT+) was developed to improve SWAT's ability in water resource modelling and management. There are only several applications of SWAT+ in large watersheds, however, no study pays attention to validate the new model at field level and assess its performance. To test the basic hydrologic function of SWAT+, it was implemented in five field cases across five states in the U.S. and compared the SWAT+ created results with that from the previous models at the same fields. Additionally, an automatic calibration tool was used to test which model is easier to be calibrated well in a limited number of parameter adjustments. The goal of the study was to evaluate the performance of SWAT+ in simulating stream flow on field level at different geographical locations. The results demonstrate that SWAT+ demonstrated similar performance with previous SWAT model, but the flexibility offered by SWAT+ via the connection of different spatial objects can result in a more accurate simulation of hydrological processes in spatial, especially for watershed with artificial facilities. Autocalibration shows that SWAT+ is much easier to obtain a satisfied result compared with the previous SWAT. Although many capabilities have already been enhanced in SWAT+, there exist inaccuracies in simulation. This insufficiency will be improved with advancements in scientific knowledge on hydrologic process in specific watersheds. Currently, SWAT+ is prerelease, and any errors are being addressed.

  4. [Effect of previous experience in reacting to a danger signal on "open field" behavior in the rat].

    Science.gov (United States)

    Poltyreva, T E; Petrov, E S

    1983-01-01

    Modification of rats behaviour in an "hopen field" test was investigated, induced by an acoustic stimulus, previously subjected to conditioning in a shuttle chamber in experiments with possibility and impossibility of avoidance from electrical shock. It has been established that presentation of a stimulus having the meaning of a danger signal, in a new situation, significantly suppresses investigating behaviour of rats, whereas the stimulus which had not been subjected to conditioning exerts no marked effect on behaviour. The greatest suppression was observed in rats with "learned helplessness". This fact suggests that the degree of suppression of the behaviour in an open field in response to a danger signal, depends on the animal's previous experience in reacting to this signal.

  5. Validation of a Previously Developed Geospatial Model That Predicts the Prevalence of Listeria monocytogenes in New York State Produce Fields

    Science.gov (United States)

    Weller, Daniel; Shiwakoti, Suvash; Bergholz, Peter; Grohn, Yrjo; Wiedmann, Martin

    2015-01-01

    Technological advancements, particularly in the field of geographic information systems (GIS), have made it possible to predict the likelihood of foodborne pathogen contamination in produce production environments using geospatial models. Yet, few studies have examined the validity and robustness of such models. This study was performed to test and refine the rules associated with a previously developed geospatial model that predicts the prevalence of Listeria monocytogenes in produce farms in New York State (NYS). Produce fields for each of four enrolled produce farms were categorized into areas of high or low predicted L. monocytogenes prevalence using rules based on a field's available water storage (AWS) and its proximity to water, impervious cover, and pastures. Drag swabs (n = 1,056) were collected from plots assigned to each risk category. Logistic regression, which tested the ability of each rule to accurately predict the prevalence of L. monocytogenes, validated the rules based on water and pasture. Samples collected near water (odds ratio [OR], 3.0) and pasture (OR, 2.9) showed a significantly increased likelihood of L. monocytogenes isolation compared to that for samples collected far from water and pasture. Generalized linear mixed models identified additional land cover factors associated with an increased likelihood of L. monocytogenes isolation, such as proximity to wetlands. These findings validated a subset of previously developed rules that predict L. monocytogenes prevalence in produce production environments. This suggests that GIS and geospatial models can be used to accurately predict L. monocytogenes prevalence on farms and can be used prospectively to minimize the risk of preharvest contamination of produce. PMID:26590280

  6. On the Tengiz petroleum deposit previous study

    International Nuclear Information System (INIS)

    Nysangaliev, A.N.; Kuspangaliev, T.K.

    1997-01-01

    Tengiz petroleum deposit previous study is described. Some consideration about structure of productive formation, specific characteristic properties of petroleum-bearing collectors are presented. Recommendation on their detail study and using of experience on exploration and development of petroleum deposit which have analogy on most important geological and industrial parameters are given. (author)

  7. Validation of a Previously Developed Geospatial Model That Predicts the Prevalence of Listeria monocytogenes in New York State Produce Fields.

    Science.gov (United States)

    Weller, Daniel; Shiwakoti, Suvash; Bergholz, Peter; Grohn, Yrjo; Wiedmann, Martin; Strawn, Laura K

    2016-02-01

    Technological advancements, particularly in the field of geographic information systems (GIS), have made it possible to predict the likelihood of foodborne pathogen contamination in produce production environments using geospatial models. Yet, few studies have examined the validity and robustness of such models. This study was performed to test and refine the rules associated with a previously developed geospatial model that predicts the prevalence of Listeria monocytogenes in produce farms in New York State (NYS). Produce fields for each of four enrolled produce farms were categorized into areas of high or low predicted L. monocytogenes prevalence using rules based on a field's available water storage (AWS) and its proximity to water, impervious cover, and pastures. Drag swabs (n = 1,056) were collected from plots assigned to each risk category. Logistic regression, which tested the ability of each rule to accurately predict the prevalence of L. monocytogenes, validated the rules based on water and pasture. Samples collected near water (odds ratio [OR], 3.0) and pasture (OR, 2.9) showed a significantly increased likelihood of L. monocytogenes isolation compared to that for samples collected far from water and pasture. Generalized linear mixed models identified additional land cover factors associated with an increased likelihood of L. monocytogenes isolation, such as proximity to wetlands. These findings validated a subset of previously developed rules that predict L. monocytogenes prevalence in produce production environments. This suggests that GIS and geospatial models can be used to accurately predict L. monocytogenes prevalence on farms and can be used prospectively to minimize the risk of preharvest contamination of produce. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  8. Influence of previous knowledge in Torrance tests of creative thinking

    OpenAIRE

    Aranguren, María; Consejo Nacional de Investigaciones Científicas y Técnicas CONICET

    2015-01-01

    The aim of this work is to analyze the influence of study field, expertise and recreational activities participation in Torrance Tests of Creative Thinking (TTCT, 1974) performance. Several hypotheses were postulated to explore the possible effects of previous knowledge in TTCT verbal and TTCT figural university students’ outcomes. Participants in this study included 418 students from five study fields: Psychology;Philosophy and Literature, Music; Engineering; and Journalism and Advertisin...

  9. Alfalfa (Medicago sativa L.) is tolerant to higher levels of salinity than previous guidelines indicated: Implications of field and greenhouse studies

    Science.gov (United States)

    Putnam, Daniel H.; Benes, Sharon; Galdi, Giuliano; Hutmacher, Bob; Grattan, Steve

    2017-04-01

    Alfalfa (Medicago sativa L.) is the most widely grown leguminous forage crop in North America and is valued for high productivity, quality, economic value, and for dairy productivity. Alfalfa has historically been classified as moderately sensitive to saline conditions, with yield declines predicted at >2 dS/m in the saturated soil paste extract. However, greenhouse, sand tank, and field studies over the past five years have confirmed that alfalfa can be grown with limited negative effects at much higher salinity levels. A broad collection of alfalfa varieties has exhibited a range of resistance at irrigation water salinities >5 dS/m ECw in greenhouse trials, with significant variation due to variety. USDA-ARS sand tank studies indicated similar or greater tolerances closer to 8 dS/m in the soil water, in addition to confirmation of significant varietal differences. A three-year field study on clay loam soil with applications of 5-7 dS/m ECw irrigation water indicated normal yields and excellent stand survivability. A second field study in the same soil type with levels from 8-10 dS/m ECw showed yield reductions of 10-15% but economic yields were still achieved at those levels. Field and greenhouse studies were conducted with mixed salt saline sodic waters typical of the San Joaquin Valley of California. Field evaluation of variety performance was subject to greater variation due to secondary salinity-soil interactions including water infiltration and crusting problems, not only salinity per-se. Thus, adequate irrigation water availability to the crop may be as important as salinity in impacting yields under field conditions. Once established, the deep-rooted characteristics of alfalfa enable utilization of deeper subsurface moisture, even at moderate to high salinity levels, as documented by USDA lysimeter studies. Significant advantages to salinity-tolerant varieties have been observed. It will be important to consider specific management factors which may enable

  10. 40 CFR 152.93 - Citation of a previously submitted valid study.

    Science.gov (United States)

    2010-07-01

    ... Data Submitters' Rights § 152.93 Citation of a previously submitted valid study. An applicant may demonstrate compliance for a data requirement by citing a valid study previously submitted to the Agency. The... the original data submitter, the applicant may cite the study only in accordance with paragraphs (b...

  11. High field Moessbauer study of dilute Ir-(Fe) alloys

    International Nuclear Information System (INIS)

    Takabatake, Toshiro; Mazaki, Hiromasa; Shinjo, Teruya.

    1981-01-01

    The magnetic behavior of very dilute Fe impurities in Ir has been studied by means of Moessbauer measurement in external fields up to 80 kOe at 4.2 K. The saturation hyperfine field increases in proportion to the external field up to the maximum magnetic field available. This means that for a localized spin fluctuation system IrFe, the effective magnetic moment associated with Fe impurities is induced in proportion to the external field. No anomalous spectrum was observed with a very dilute sample (--10 ppm 57 Co), indicating that the interaction between impurities is responsible for the anomalous spectrum previously observed with a less homogeneous sample. (author)

  12. Experimental study on the luminous radiation associated to the field emission of samples submitted to high RF fields

    International Nuclear Information System (INIS)

    Maissa, S.; Junquera, T.; Fouaidy, M.; Le Goff, A.; Luong, M.; Tan, J.; Bonin, B.; Safa, H.

    1996-01-01

    The accelerating gradient of the RF cavities is limited by the strong field emission (FE) of electrons stemming from the metallic walls. Previous experiments evidenced luminous radiations associated with electron emission of cathodes subjected to intense DC electric field. These observations invoked the proposal of new theoretical models of the field emission phenomenon. This experimental study extends the previous DC works to the RF case. A special copper RF cavity has been developed equipped with an optical window and a removable sample. It has been designed for measuring both electron current and luminous radiation emitted by the sample, subjected to maximum RF electric field. The optical apparatus attached to the cavity permits to characterize the radiation in terms of intensity, glowing duration and spectral distribution. The results concerning different niobium or copper samples, whom top was either scratched or intentionally contaminated with metallic or dielectric particles are summarized. (author)

  13. Fluorescence excitation studies of molecular photoionization in external electric fields

    International Nuclear Information System (INIS)

    Poliakoff, E.D.; Dehmer, J.L.; Parr, A.C.; Leroi, G.E.

    1985-01-01

    Using molecular nitrogen as an example, we show that fluorescence excitation spectroscopy can be used to measure partial photoionization cross sections of free molecules in external electric fields. The production of the N 2 + (B 2 Σ/sub u/ + ) state was studied and the threshold for this process was found to shift linearly with the square root of the applied field. This behavior is compared with the hydrogenic case and with previously studied systems

  14. Statistical Study of Interplanetary Coronal Mass Ejections with Strong Magnetic Fields

    Science.gov (United States)

    Murphy, Matthew E.

    Coronal Mass Ejections (CMEs) with strong magnetic fields (B ) are typically associated with significant Solar Energetic Particle (SEP) events, high solar wind speed and solar flare events. Successful prediction of the arrival time of a CME at Earth is required to maximize the time available for satellite, infrastructure, and space travel programs to take protective action against the coming flux of high-energy particles. It is known that the magnetic field strength of a CME is linked to the strength of a geomagnetic storm on Earth. Unfortunately, the correlations between strong magnetic field CMEs from the entire sun (especially from the far side or non-Earth facing side of the sun) to SEP and flare events, solar source regions and other relevant solar variables are not well known. New correlation studies using an artificial intelligence engine (Eureqa) were performed to study CME events with magnetic field strength readings over 30 nanoteslas (nT) from January 2010 to October 17, 2014. This thesis presents the results of this study, validates Eureqa to obtain previously published results, and presents previously unknown functional relationships between solar source magnetic field data, CME initial speed and the CME magnetic field. These new results enable the development of more accurate CME magnetic field predictions and should help scientists develop better forecasts thereby helping to prevent damage to humanity's space and Earth assets.

  15. Lack of Cetuximab induced skin toxicity in a previously irradiated field: case report and review of the literature

    Science.gov (United States)

    2010-01-01

    Introduction Mutation, amplification or dysregulation of the EGFR family leads to uncontrolled division and predisposes to cancer. Inhibiting the EGFR represents a form of targeted cancer therapy. Case report We report the case of 79 year old gentlemen with a history of skin cancer involving the left ear who had radiation and surgical excision. He had presented with recurrent lymph node in the left upper neck. We treated him with radiation therapy concurrently with Cetuximab. He developed a skin rash over the face and neck area two weeks after starting Cetuximab, which however spared the previously irradiated area. Conclusion The etiology underlying the sparing of the previously irradiated skin maybe due to either decrease in the population of EGFR expressing cells or decrease in the EGFR expression. We raised the question that "Is it justifiable to use EGFR inhibitors for patients having recurrence in the previously irradiated field?" We may need further research to answer this question which may guide the physicians in choosing appropriate drug in this scenario. PMID:20478052

  16. The impact of previous knee injury on force plate and field-based measures of balance.

    Science.gov (United States)

    Baltich, Jennifer; Whittaker, Jackie; Von Tscharner, Vinzenz; Nettel-Aguirre, Alberto; Nigg, Benno M; Emery, Carolyn

    2015-10-01

    Individuals with post-traumatic osteoarthritis demonstrate increased sway during quiet stance. The prospective association between balance and disease onset is unknown. Improved understanding of balance in the period between joint injury and disease onset could inform secondary prevention strategies to prevent or delay the disease. This study examines the association between youth sport-related knee injury and balance, 3-10years post-injury. Participants included 50 individuals (ages 15-26years) with a sport-related intra-articular knee injury sustained 3-10years previously and 50 uninjured age-, sex- and sport-matched controls. Force-plate measures during single-limb stance (center-of-pressure 95% ellipse-area, path length, excursion, entropic half-life) and field-based balance scores (triple single-leg hop, star-excursion, unipedal dynamic balance) were collected. Descriptive statistics (mean within-pair difference; 95% confidence intervals) were used to compare groups. Linear regression (adjusted for injury history) was used to assess the relationship between ellipse-area and field-based scores. Injured participants on average demonstrated greater medio-lateral excursion [mean within-pair difference (95% confidence interval); 2.8mm (1.0, 4.5)], more regular medio-lateral position [10ms (2, 18)], and shorter triple single-leg hop distances [-30.9% (-8.1, -53.7)] than controls, while no between group differences existed for the remaining outcomes. After taking into consideration injury history, triple single leg hop scores demonstrated a linear association with ellipse area (β=0.52, 95% confidence interval 0.01, 1.01). On average the injured participants adjusted their position less frequently and demonstrated a larger magnitude of movement during single-limb stance compared to controls. These findings support the evaluation of balance outcomes in the period between knee injury and post-traumatic osteoarthritis onset. Copyright © 2015 Elsevier Ltd. All rights

  17. Experimental study on the luminous radiation associated to the field emission of samples submitted to high RF fields

    International Nuclear Information System (INIS)

    Maissa, S.; Junquera, T.; Fouaidy, M.; Le Goff, A.; Luong, M.; Tan, J.; Bonin, B.; Safa, H.

    1996-01-01

    Nowadays the accelerating gradient of the RF cavities is limited by the strong field emission (FE) of electrons stemming from the metallic walls. Previous experiments evidenced luminous radiations associated with electron emission on cathodes subjected to intense DC electric field. These observations led these authors to propose new theoretical models of the field emission phenomenon. The presented experimental study extends these previous DC works to the RF case. A special copper RF cavity has been developed equipped with an optical window and a removable sample. It has been designed for measuring both electron current and luminous radiation emitted by the sample, subjected to maximum RF electric field. The optical apparatus attached to the cavity permits to characterize the radiation in terms of intensity, glowing duration and spectral distribution. The results concerning different niobium or copper samples, whom top was either scratched or intentionally contaminated with metallic or dielectric particles are summarized. (author)

  18. Influence of Previous Knowledge in Torrance Tests of Creative Thinking

    Directory of Open Access Journals (Sweden)

    María Aranguren

    2015-07-01

    Full Text Available The aim of this work is to analyze the influence of study field, expertise and recreational activities participation in Torrance Tests of Creative Thinking (TTCT, 1974 performance. Several hypotheses were postulated to explore the possible effects of previous knowledge in TTCT verbal and TTCT figural university students’ outcomes. Participants in this study included 418 students from five study fields: Psychology;Philosophy and Literature, Music; Engineering; and Journalism and Advertising (Communication Sciences. Results found in this research seem to indicate that there in none influence of the study field, expertise and recreational activities participation in neither of the TTCT tests. Instead, the findings seem to suggest some kind of interaction between certain skills needed to succeed in specific studies fields and performance on creativity tests, such as the TTCT. These results imply that TTCT is a useful and valid instrument to measure creativity and that some cognitive process involved in innovative thinking can be promoted using different intervention programs in schools and universities regardless the students study field.

  19. Faraday Rotation Measure Study of Cluster Magnetic Fields

    Science.gov (United States)

    Frankel, M. M.; Clarke, T. E.

    2001-12-01

    Magnetic fields are thought to play an important role in galaxy cluster evolution. To this end in this study, we looked at polarized radio sources viewed at small impact parameters to the cores of non-cooling flow clusters. By looking at non-cooling flow clusters we hoped to establish what magnetic fields of clusters look like in the absence of the compressed central magnetic fields of the cooling-flow cores. Clarke, Kronberg and Boehringer (2001) examined Faraday rotation measures of radio probes at relatively large impact parameters to the cores of galaxy clusters. The current study is an extension of the Clarke et al. analysis to probe the magnetic fields in the cores of galaxy clusters. We looked at the Faraday rotation of electromagnetic waves from background or imbedded radio galaxies, which were observed with the VLA in A&B arrays. Our results are consistent with previous findings and exhibit a trend towards higher rotation measures and in turn higher magnetic fields at small impact parameters to cluster cores. This research was made possible through funding from the National Science Foundation.

  20. Wide-field spectral imaging of human ovary autofluorescence and oncologic diagnosis via previously collected probe data

    Science.gov (United States)

    Renkoski, Timothy E.; Hatch, Kenneth D.; Utzinger, Urs

    2012-03-01

    With no sufficient screening test for ovarian cancer, a method to evaluate the ovarian disease state quickly and nondestructively is needed. The authors have applied a wide-field spectral imager to freshly resected ovaries of 30 human patients in a study believed to be the first of its magnitude. Endogenous fluorescence was excited with 365-nm light and imaged in eight emission bands collectively covering the 400- to 640-nm range. Linear discriminant analysis was used to classify all image pixels and generate diagnostic maps of the ovaries. Training the classifier with previously collected single-point autofluorescence measurements of a spectroscopic probe enabled this novel classification. The process by which probe-collected spectra were transformed for comparison with imager spectra is described. Sensitivity of 100% and specificity of 51% were obtained in classifying normal and cancerous ovaries using autofluorescence data alone. Specificity increased to 69% when autofluorescence data were divided by green reflectance data to correct for spatial variation in tissue absorption properties. Benign neoplasm ovaries were also found to classify as nonmalignant using the same algorithm. Although applied ex vivo, the method described here appears useful for quick assessment of cancer presence in the human ovary.

  1. Numerical simulation of the shot peening process under previous loading conditions

    International Nuclear Information System (INIS)

    Romero-Ángeles, B; Urriolagoitia-Sosa, G; Torres-San Miguel, C R; Molina-Ballinas, A; Benítez-García, H A; Vargas-Bustos, J A; Urriolagoitia-Calderón, G

    2015-01-01

    This research presents a numerical simulation of the shot peening process and determines the residual stress field induced into a component with a previous loading history. The importance of this analysis is based on the fact that mechanical elements under shot peening are also subjected to manufacturing processes, which convert raw material into finished product. However, material is not provided in a virgin state, it has a previous loading history caused by the manner it is fabricated. This condition could alter some beneficial aspects of the residual stress induced by shot peening and could accelerate the crack nucleation and propagation progression. Studies were performed in beams subjected to strain hardening in tension (5ε y ) before shot peening was applied. Latter results were then compared in a numerical assessment of an induced residual stress field by shot peening carried out in a component (beam) without any previous loading history. In this paper, it is clearly shown the detrimental or beneficial effect that previous loading history can bring to the mechanical component and how it can be controlled to improve the mechanical behavior of the material

  2. Exposure to magnetic fields and survival after diagnosis of childhood leukemia: a German cohort study

    DEFF Research Database (Denmark)

    Svendsen, Anne Louise; Weihkopf, Thomas; Kaatsch, Peter

    2007-01-01

    Inspired by a recent U.S. study showing poorer survival among children with acute lymphoblastic leukemia (ALL) exposed to magnetic fields above 0.3 microT, we examine this relationship in a German cohort of childhood leukemia cases derived from previous population-based case-control studies...... for prognostic risk group, the hazard for exposures above 0.2 microT increases to HR, 3.0 (95% CI, 0.9-9.8). In conclusion, this study is generally consistent with the previous finding; however, we report the excess risk at field levels lower than those in the U.S. study. In all, the evidence is still based...

  3. Study of functional-performance deficits in athletes with previous ankle sprains

    Directory of Open Access Journals (Sweden)

    hamid Babaee

    2008-04-01

    Full Text Available Abstract Background: Despite the importance of functional-performance deficits in athletes with history of ankle sprain few, studies have been carried out in this area. The aim of this research was to study relationship between previous ankle sprains and functional-performance deficits in athletes. Materials and methods: The subjects were 40 professional athletes selected through random sampling among volunteer participants in soccer, basketball, volleyball and handball teams of Lorestan province. The subjects were divided into 2 groups: Injured group (athletes with previous ankle sprains and healthy group (athletes without previous ankle sprains. In this descriptive study we used Functional-performance tests (figure 8 hop test and side hop test to determine ankle deficits and limitations. They participated in figure 8 hop test including hopping in 8 shape course with the length of 5 meters and side hop test including 10 side hop repetitions in course with the length of 30 centimeters. Time were recorded via stopwatch. Results: After data gathering and assessing information distributions, Pearson correlation was used to assess relationships, and independent T test to assess differences between variables. Finally the results showed that there is a significant relationship between previous ankle sprains and functional-performance deficits in the athletes. Conclusion: The athletes who had previous ankle sprains indicated functional-performance deficits more than healthy athletes in completion of mentioned functional-performance tests. The functional-performance tests (figure 8 hop test and side hop test are sensitive and suitable to assess and detect functional-performance deficits in athletes. Therefore we can use the figure 8 hop and side hop tests for goals such as prevention, assessment and rehabilitation of ankle sprains without spending too much money and time.

  4. Personality disorders in previously detained adolescent females: a prospective study

    NARCIS (Netherlands)

    Krabbendam, A.; Colins, O.F.; Doreleijers, T.A.H.; van der Molen, E.; Beekman, A.T.F.; Vermeiren, R.R.J.M.

    2015-01-01

    This longitudinal study investigated the predictive value of trauma and mental health problems for the development of antisocial personality disorder (ASPD) and borderline personality disorder (BPD) in previously detained women. The participants were 229 detained adolescent females who were assessed

  5. Field study plan for alternate barriers

    International Nuclear Information System (INIS)

    Freeman, H.D.; Gee, G.W.; Relyea, J.F.

    1989-05-01

    Pacific Northwest Laboratory (PNL) is providing technical assistance in selecting, designing, evaluating, and demonstrating protective barriers. As part of this technical assistance effort, asphalt, clay, and chemical grout will be evaluated for use as alternate barriers. The purpose of the subsurface layer is to reduce the likelihood that extreme events (i.e., 100-year maximum storms, etc.) will cause significant drainage through the barrier. The tests on alternate barriers will include laboratory and field analysis of the subsurface layer performance. This field test plan outlines the activities required to test and design subsurface moisture barriers. The test plan covers activities completed in FY 1988 and planned through FY 1992 and includes a field-scale test of one or more of the alternate barriers to demonstrate full-scale application techniques and to provide performance data on a larger scale. Tests on asphalt, clay, and chemical grout were initiated in FY 1988 in small (30.5 cm diameter) tube-layer lysimeters. The parameters used for testing the materials were different for each one. The tests had to take into account the differences in material characteristics and response to change in conditions, as well as information provided by previous studies. 33 refs., 8 figs., 1 tab

  6. Construction of an interim storage field using recovered municipal solid waste incineration bottom ash: Field performance study.

    Science.gov (United States)

    Sormunen, Laura Annika; Kolisoja, Pauli

    2017-06-01

    The leaching of hazardous substances from municipal solid waste incineration (MSWI) bottom ash (BA) has been studied in many different scales for several years. Less attention has been given to the mechanical performance of MSWI BA in actual civil engineering structures. The durability of structures built with this waste derived material can have major influence on the functional properties of such structures and also the potential leaching of hazardous substances in the long term. Hence, it is necessary to properly evaluate in which type of structures MSWI BA can be safely used in a similar way as natural and crushed rock aggregates. In the current study, MSWI BA treated with ADR (Advance Dry Recovery) technology was used in the structural layers of an interim storage field built within a waste treatment centre. During and half a year after the construction, the development of technical and mechanical properties of BA materials and the built structures were investigated. The aim was to compare these results with the findings of laboratory studies in which the same material was previously investigated. The field results showed that the mechanical performance of recovered BA corresponds to the performance of natural aggregates in the lower structural layers of field structures. Conversely, the recovered MSWI BA cannot be recommended to be used in the base layers as such, even though its stiffness properties increased over time due to material aging and changes in moisture content. The main reason for this is that BA particles are prone for crushing and therefore inadequate to resist the higher stresses occurring in the upper parts of road and field structures. These results were in accordance with the previous laboratory findings. It can thus be concluded that the recovered MSWI BA is durable to be used as a replacement of natural aggregates especially in the lower structural layers of road and field structures, whereas if used in the base layers, an additional base

  7. Field electron emission spectrometer combined with field ion/electron microscope as a field emission laboratory

    International Nuclear Information System (INIS)

    Shkuratov, S.I.; Ivanov, S.N.; Shilimanov, S.N.

    1996-01-01

    The facility, combining the field ion microscope, field electron emission microscope and field electron emission spectrometer, is described. Combination of three methodologies makes it possible to carry out the complete cycle of emission studies. Atom-plane and clean surface of the studied samples is prepared by means of field evaporation of the material atom layers without any thermal and radiation impact. This enables the study of atom and electron structure of clean surface of the wide range materials, the study whereof through the field emission methods was previously rather difficult. The temperature of the samples under study changes from 75 up to 2500 K. The energy resolution of the electron analyzer equals 30 MeV. 19 refs., 10 figs

  8. Competition Between Fusarium pseudograminearum and Cochliobolus sativus Observed in Field and Greenhouse Studies.

    Science.gov (United States)

    Troth, Erin E Gunnink; Johnston, Jeffrey A; Dyer, Alan T

    2018-02-01

    Among root pathogens, one of the most documented antagonisms is the suppression of Cochliobolus sativus by Fusarium (roseum) species. Unfortunately, previous studies involved single isolates of each pathogen and thus, provided no indication of the spectrum of responses that occur across the respective species. To investigate the variability in interactions between Cochliobolus sativus and Fusarium pseudograminearum, field and greenhouse trials were conducted that included monitoring of spring wheat plant health and monitoring of pathogen populations via quantitative real-time polymerase chain reaction. The interactions between two isolates of C. sativus and four isolates of F. pseudograminearum were explored in three geographically distinct wheat fields. To complement field trials and to limit potentially confounding environmental variables that are often associated with field studies, greenhouse trials were performed that investigated the interactions among and between three isolates of C. sativus and four isolates of F. pseudograminearum. Across field locations, C. sativus isolate Cs2344 consistently and significantly reduced Fusarium populations by an average of 20.1%. Similarly, F. pseudograminearum isolate Fp2228 consistently and significantly reduced C. sativus field populations by an average of 30.9%. No interaction was detected in the field between pathogen species with regards to disease or crop losses. Greenhouse results confirmed a powerful (>99%), broadly effective suppression of Fusarium populations by isolate Cs2344. Among greenhouse trials, additional isolate-isolate interactions were observed affecting Fusarium populations. Due to lower C. sativus population sizes in greenhouse trials, significant Fusarium suppression of C. sativus was only detected in one isolate-isolate interaction. This study is the first to demonstrate suppression of Fusarium spp. by C. sativus in field and greenhouse settings. These findings also reveal a complex competitive

  9. Matched cohort study of external cephalic version in women with previous cesarean delivery.

    Science.gov (United States)

    Keepanasseril, Anish; Anand, Keerthana; Soundara Raghavan, Subrahmanian

    2017-07-01

    To evaluate the efficacy and safety of external cephalic version (ECV) among women with previous cesarean delivery. A retrospective study was conducted using data for women with previous cesarean delivery and breech presentation who underwent ECV at or after 36 weeks of pregnancy during 2011-2016. For every case, two multiparous women without previous cesarean delivery who underwent ECV and were matched for age and pregnancy duration were included. Characteristics and outcomes were compared between groups. ECV was successful for 32 (84.2%) of 38 women with previous cesarean delivery and 62 (81.6%) in the control group (P=0.728). Multivariate regression analysis confirmed that previous cesarean was not associated with ECV success (odds ratio 1.89, 95% confidence interval 0.19-18.47; P=0.244). Successful vaginal delivery after successful ECV was reported for 19 (59.4%) women in the previous cesarean delivery group and 52 (83.9%) in the control group (P<0.001). No ECV-associated complications occurred in women with previous cesarean delivery. To avoid a repeat cesarean delivery, ECV can be offered to women with breech presentation and previous cesarean delivery who are otherwise eligible for a trial of labor. © 2017 International Federation of Gynecology and Obstetrics.

  10. Compact Reversed-Field Pinch Reactors (CRFPR): fusion-power-core integration study

    International Nuclear Information System (INIS)

    Copenhaver, C.; Krakowski, R.A.; Schnurr, N.M.

    1985-08-01

    Using detailed two-dimensional neutronics studies based on the results of a previous framework study (LA-10200-MS), the fusion-power-core (FPC) integration, maintenance, and radio-activity/afterheat control are examined for the Compact Reversed-Field Pinch Reactor (CRFPR). While maintaining as a base case the nominal 20-MW/m 2 neutron first-wall loading design, CRFPR(20), the cost and technology impact of lower-wall-loading designs are also examined. The additional detail developed as part of this follow-on study also allows the cost estimates to be refined. The cost impact of multiplexing lower-wall-loading FPCs into a approx. 1000-MWe(net) plant is also examined. The CRFPR(20) design remains based on a PbLi-cooled FPC with pressurized-water used as a coolant for first-wall, pumped-limiter, and structural-shield systems. Single-piece FPC maintenance of this steady-state power plant is envisaged and evaluated on the basis of a preliminary layout of the reactor building. This follow-on study also develops the groundwork for assessing the feasibility and impact of impurity/ash control by magnetic divertors as an alternative to previously considered pumped-limiter systems. Lastly, directions for future, more-detailed power-plant designs based on the Reversed-Field Pinch are suggested

  11. Erlotinib-induced rash spares previously irradiated skin

    International Nuclear Information System (INIS)

    Lips, Irene M.; Vonk, Ernest J.A.; Koster, Mariska E.Y.; Houwing, Ronald H.

    2011-01-01

    Erlotinib is an epidermal growth factor receptor inhibitor prescribed to patients with locally advanced or metastasized non-small cell lung carcinoma after failure of at least one earlier chemotherapy treatment. Approximately 75% of the patients treated with erlotinib develop acneiform skin rashes. A patient treated with erlotinib 3 months after finishing concomitant treatment with chemotherapy and radiotherapy for non-small cell lung cancer is presented. Unexpectedly, the part of the skin that had been included in his previously radiotherapy field was completely spared from the erlotinib-induced acneiform skin rash. The exact mechanism of erlotinib-induced rash sparing in previously irradiated skin is unclear. The underlying mechanism of this phenomenon needs to be explored further, because the number of patients being treated with a combination of both therapeutic modalities is increasing. The therapeutic effect of erlotinib in the area of the previously irradiated lesion should be assessed. (orig.)

  12. Does self-confidence link to motivation? A study in field hockey athletes

    OpenAIRE

    Sari, İhsan; Ekici, Sümmani; Soyer, Fikret; Eskiler, Ersin

    2015-01-01

    Previous research indicated some evidence of a positive relationship between motivation and self-efficacy beliefs/perceived competence/self-perceptions. Therefore, the relationship between self-confidence and motivation was investigated in sport context in this study. Participants of this study were 111 field hockey athletes. Sport Motivation Scale (Pelletier et al., 1995) and Self-confidence Scales (Tokinan, 2008) were used for data collection. SPSS.17 package program was used to analyse the...

  13. Conduct of a personal radiofrequency electromagnetic field measurement study: proposed study protocol.

    Science.gov (United States)

    Röösli, Martin; Frei, Patrizia; Bolte, John; Neubauer, Georg; Cardis, Elisabeth; Feychting, Maria; Gajsek, Peter; Heinrich, Sabine; Joseph, Wout; Mann, Simon; Martens, Luc; Mohler, Evelyn; Parslow, Roger C; Poulsen, Aslak Harbo; Radon, Katja; Schüz, Joachim; Thuroczy, György; Viel, Jean-François; Vrijheid, Martine

    2010-05-20

    The development of new wireless communication technologies that emit radio frequency electromagnetic fields (RF-EMF) is ongoing, but little is known about the RF-EMF exposure distribution in the general population. Previous attempts to measure personal exposure to RF-EMF have used different measurement protocols and analysis methods making comparisons between exposure situations across different study populations very difficult. As a result, observed differences in exposure levels between study populations may not reflect real exposure differences but may be in part, or wholly due to methodological differences. The aim of this paper is to develop a study protocol for future personal RF-EMF exposure studies based on experience drawn from previous research. Using the current knowledge base, we propose procedures for the measurement of personal exposure to RF-EMF, data collection, data management and analysis, and methods for the selection and instruction of study participants. We have identified two basic types of personal RF-EMF measurement studies: population surveys and microenvironmental measurements. In the case of a population survey, the unit of observation is the individual and a randomly selected representative sample of the population is needed to obtain reliable results. For microenvironmental measurements, study participants are selected in order to represent typical behaviours in different microenvironments. These two study types require different methods and procedures. Applying our proposed common core procedures in future personal measurement studies will allow direct comparisons of personal RF-EMF exposures in different populations and study areas.

  14. Studying the field induced breakup of acoustically levitated drops

    Science.gov (United States)

    Warschat, C.; Riedel, J.

    2017-10-01

    Coulomb fission of charged droplets (The terms drop and droplet are often used synonymous. Throughout this manuscript, to avoid confusion, the terms drop and droplet will be used for liquid spheres with radii in the millimeter range and the micrometer range, respectively. In our experiments, the first correspond to the parent drop while the latter describes the ejected progeny droplets.) is a well-studied natural phenomenon. Controlled droplet fission is already successfully employed in several technological applications. Still, since the occurring surface rupture relies on the exact understanding and description of the liquid gas boundary, some details are still under debate. Most empirical systematic studies observe falling micrometer droplets passing through the electric field inside a plate capacitor. This approach, although easily applicable and reliable, limits the experimental degrees of freedom regarding the observable time and the maximum size of the drops and can only be performed in consecutive individual observations of different subsequent drops. Here we present a novel setup to study the field induced breakup of acoustically levitated drops. The design does not bear any restrictions towards the temporal window of observation, and allows handling of drops of a tunable radius ranging from 10 μm to several millimeters and a real-time monitoring of one single drop. Our comprehensive study includes a time resolved visual inspection, laser shadowgraphy, laser induced fluorescence imaging, and ambient mass spectrometric interrogation of the nascent Taylor cone. The results shown for a millimeter sized drop, previously inaccessible for Coulomb fission experiments, are mostly comparable with previous results for smaller drops. The major difference is the time scale and the threshold potential of the drop rupture. Both values, however, resemble theoretically extrapolations to the larger radius. The technique allows for a systematic study of breakup behavior of

  15. Preliminary Findings from the One-Year Electric Field Study in the North Slope of Alaska (OYES-NSA), Atmospheric Radiation Measurement (ARM) Field Campaign

    Science.gov (United States)

    Lavigne, T.; Liu, C.

    2017-12-01

    Previous studies focusing on the comparison of the measured electric field to the physical properties of global electrified clouds have been conducted almost exclusively in the Southern Hemisphere. The One-Year Electric Field Study-North Slope of Alaska (OYES-NSA) aims to establish a long-running collection of this valuable electric field data in the Northern Hemisphere. Presented here is the six-month preliminary data and results of the OYES-NSA Atmospheric Radiation Mission (ARM) field campaign. The local electric field measured in Barrow, Alaska using two CS110 reciprocating shutter field meters, has been compared to simultaneous measurements from the ARM Ka-Band zenith radar, to better understand the influence and contribution of different types of clouds on the local electric field. The fair-weather electric field measured in Barrow has also been analyzed and compared to the climatology of electric field at Vostok Station, Antarctica. The combination of the electric field dataset in the Northern Hemisphere, alongside the local Ka cloud radar, global Precipitation Feature (PF) database, and quasi-global lightning activity (55oN-55oS), allows for advances in the physical understanding of the local electric field, as well as the Global Electric Circuit (GEC).

  16. Conduct of a personal radiofrequency electromagnetic field measurement study: proposed study protocol

    Directory of Open Access Journals (Sweden)

    Radon Katja

    2010-05-01

    Full Text Available Abstract Background The development of new wireless communication technologies that emit radio frequency electromagnetic fields (RF-EMF is ongoing, but little is known about the RF-EMF exposure distribution in the general population. Previous attempts to measure personal exposure to RF-EMF have used different measurement protocols and analysis methods making comparisons between exposure situations across different study populations very difficult. As a result, observed differences in exposure levels between study populations may not reflect real exposure differences but may be in part, or wholly due to methodological differences. Methods The aim of this paper is to develop a study protocol for future personal RF-EMF exposure studies based on experience drawn from previous research. Using the current knowledge base, we propose procedures for the measurement of personal exposure to RF-EMF, data collection, data management and analysis, and methods for the selection and instruction of study participants. Results We have identified two basic types of personal RF-EMF measurement studies: population surveys and microenvironmental measurements. In the case of a population survey, the unit of observation is the individual and a randomly selected representative sample of the population is needed to obtain reliable results. For microenvironmental measurements, study participants are selected in order to represent typical behaviours in different microenvironments. These two study types require different methods and procedures. Conclusion Applying our proposed common core procedures in future personal measurement studies will allow direct comparisons of personal RF-EMF exposures in different populations and study areas.

  17. Investigation of previously derived Hyades, Coma, and M67 reddenings

    International Nuclear Information System (INIS)

    Taylor, B.J.

    1980-01-01

    New Hyades polarimetry and field star photometry have been obtained to check the Hyades reddening, which was found to be nonzero in a previous paper. The new Hyades polarimetry implies essentially zero reddening; this is also true of polarimetry published by Behr (which was incorrectly interpreted in the previous paper). Four photometric techniques which are presumed to be insensitive to blanketing are used to compare the Hyades to nearby field stars; these four techniques also yield essentially zero reddening. When all of these results are combined with others which the author has previously published and a simultaneous solution for the Hyades, Coma, and M67 reddenings is made, the results are E (B-V) =3 +- 2 (sigma) mmag, -1 +- 3 (sigma) mmag, and 46 +- 6 (sigma) mmag, respectively. No support for a nonzero Hyades reddening is offered by the new results. When the newly obtained reddenings for the Hyades, Coma, and M67 are compared with results from techniques given by Crawford and by users of the David Dunlap Observatory photometric system, no differences between the new and other reddenings are found which are larger than about 2 sigma. The author had previously found that the M67 main-sequence stars have about the same blanketing as that of Coma and less blanketing than the Hyades; this conclusion is essentially unchanged by the revised reddenings

  18. Magnetic field effects on geminate reactions. Study of anthraquinone - hydrogen donors systems

    International Nuclear Information System (INIS)

    Vidal, Marie-Helene

    1987-01-01

    This study is devoted to magnetic field effects on chemical reactions which involve a radical pair with correlated spins (radical in a 'cage'). In the first part, the radical pair theory is described: mechanisms of singlet-triplet mixing, the different interactions inside the pair and a quantum mechanical treatment of the radical pair. The details of the experimental method (nanosecond laser flash photolysis) are reported in the second part. In the third part are shown experimental results obtained on Anthraquinone (AQ) - Hydrogen donors systems: - There is no magnetic field effect in homogeneous solution even at a high viscosity. The absorption spectra of the different reaction intermediates are obtained. - However a magnetic field effect is put forward when AQ is introduced in SDS micelles which are hydrogen donors. The absorption spectrum of the AQH · . semi-quinone radical in 'cage' is shown and a mechanism is proposed for its disappearance to generate the AQH-S and AQH 2 species. - The addition of 9, 10 Dihydroanthracene (DH2) inside the micelle near AQ induces an increase of the magnetic field effect by creation of (AQH · . - DH · . ) pairs which diffuse slowly. - Fixed radical pairs in a protein matrix were studied in reaction centers of photosynthetic bacteria: in that case, the half effect field is shifted to low fields when compared to the previously described systems. (author) [fr

  19. Theoretical and experimental studies of the magnetic fields of Rotamak discharge

    International Nuclear Information System (INIS)

    Kirolous, H.

    1986-12-01

    In part I of this thesis, the self-generated bi-directional toroidal magnetic field structure which has been observed to exist in previous rotamak discharges is theoretically investigated. A possible explanation for the existence of this self-generated field, which relies on the presence of screening currents in the plasma, is advanced. Experimental studies of the magnetic field structure of a rotamak plasma configuration generated and sustained in a metal discharge vessel by means of a rotating magnetic field are described in part II. The rotating magnetic field was produced by feeding radio frequency (r.f.) currents, dephased by 90 degrees, through two orthogonal coils which were located inside the metal chamber. High power amplifiers were used to supply the r.f. current pulses. The efficiency of the r.f. power transfer to the plasma was maximized by using impedance matching networks. The effect on the rotating magnetic field of eddy currents induced in the conducting vessel has been theoretically and experimentally investigated. Extensive magnetic field measurements have been undertaken on one particular rotamak discharge. Measurements of the penetration of the rotating magnetic field into the plasma were made at various axial positions. The steady magnetic field structure was measured at a matrix of 2640 points and a two dimensional least square polynomial fitting algorithm was used to smooth the measured data. This fitting procedure enabled reliable plots of the poloidal flux and current density contours to be constructed. An attempt has been made to apply MHD equilibrium theory to the observed plasma/field configuration. 23 refs., 99 figs., ills

  20. Wide Field Infra-Red Survey Telescope (WFIRST) 2.4-Meter Mission Study

    Science.gov (United States)

    Content, D.; Aaron, K.; Alplanalp, L.; Anderson, K.; Capps, R.; Chang, Z.; Dooley, J.; Egerman, R.; Goullioud, R.; Klein, D.; hide

    2013-01-01

    The most recent study of the Wide Field Infrared Survey Telescope (WFIRST) mission is based on reuse of an existing 2.4m telescope. This study was commissioned by NASA to examine the potential science return and cost effectiveness of WFIRST by using this significantly larger aperture telescope. We review the science program envisioned by the WFIRST 2012-2013 Science Definition Team (SDT), an overview of the mission concept, and the telescope design and status. Comparisons against the previous 1.3m and reduced cost 1.1m WFIRST design concepts are discussed. A significant departure from past point designs is the option for serviceability and the geostationary orbit location which enables servicing and replacement instrument insertion later during mission life. Other papers at this conference provide more in depth discussion of the wide field instrument and the optional exoplanet imaging coronagraph instrument.

  1. Monte Carlo study of dynamic phase transition in Ising metamagnet driven by oscillating magnetic field

    International Nuclear Information System (INIS)

    Acharyya, Muktish

    2011-01-01

    The dynamical responses of Ising metamagnet (layered antiferromagnet) in the presence of a sinusoidally oscillating magnetic field are studied by Monte Carlo simulation. The time average staggered magnetisation plays the role of dynamic order parameter. A dynamical phase transition was observed and a phase diagram was plotted in the plane formed by field amplitude and temperature. The dynamical phase boundary is observed to shrink inward as the relative antiferromagnetic strength decreases. The results are compared with that obtained from pure ferromagnetic system. The shape of dynamic phase boundary observed to be qualitatively similar to that obtained from previous meanfield calculations. - Highlights: → The time average staggered magnetisation plays the role of dynamic order parameter. → A dynamical phase transition was observed and a phase diagram was plotted in the plane formed by field amplitude and temperature. → The dynamical phase boundary is observed to shrink inward as the relative antiferromagnetic strength decreases. → The results are compared with that obtained from pure ferromagnetic system. → The shape of dynamic phase boundary observed to be qualitatively similar to that obtained from previous meanfield calculation.

  2. Numerical Study of Flow Motion and Patterns Driven by a Rotating Permanent Helical Magnetic Field

    Science.gov (United States)

    Yang, Wenzhi; Wang, Xiaodong; Wang, Bo; Baltaretu, Florin; Etay, Jacqueline; Fautrelle, Yves

    2016-10-01

    Liquid metal magnetohydrodynamic flow driven by a rotating permanent helical magnetic field in a cylindrical container is numerically studied. A three-dimensional numerical simulation provides insight into the visualization of the physical fields, including the magnetic field, the Lorentz force density, and the flow structures, especially the flow patterns in the meridional plane. Because the screen parameter is sufficiently small, the model is decoupled into electromagnetic and hydrodynamic components. Two flow patterns in the meridional plane, i.e., the global flow and the secondary flow, are discovered and the impact of several system parameters on their transition is investigated. Finally, a verifying model is used for comparison with the previous experiment.

  3. Outcome of secondary high-grade glioma in children previously treated for a malignant condition: A study of the Canadian Pediatric Brain Tumour Consortium

    International Nuclear Information System (INIS)

    Carret, Anne-Sophie; Tabori, Uri; Crooks, Bruce; Hukin, Juliette; Odame, Isaac; Johnston, Donna L.; Keene, Daniel L.; Freeman, Carolyn; Bouffet, Eric

    2006-01-01

    Background and purpose: Reports of secondary high-grade glioma (HGG) in survivors of childhood cancer are scarce. The aim of this study was to review the pattern of diagnosis, the treatment, and outcome of secondary pediatric HGG. Patients and methods: We performed a multi-center retrospective study among the 17 paediatric institutions participating in the Canadian Pediatric Brain Tumour Consortium (CPBTC). Results: We report on 18 patients (14 males, 4 females) treated in childhood for a primary cancer, who subsequently developed a HGG as a second malignancy. All patients had previously received radiation therapy +/- chemotherapy for either acute lymphoblastic leukaemia (n = 9) or solid tumour (n = 9). All HGG occurred within the previous radiation fields. At the last follow-up, 17 patients have died and the median survival time is 9.75 months. Conclusion: Although aggressive treatment seems to provide sustained remissions in some patients, the optimal management is still to be defined. Further documentation of such cases is necessary in order to better understand the pathogenesis, the natural history and the prevention of these tumours

  4. Study of some physical aspects previous to design of an exponential experiment

    International Nuclear Information System (INIS)

    Caro, R.; Francisco, J. L. de

    1961-01-01

    This report presents the theoretical study of some physical aspects previous to the design of an exponential facility. The are: Fast and slow flux distribution in the multiplicative medium and in the thermal column, slowing down in the thermal column, geometrical distribution and minimum needed intensity of sources access channels and perturbations produced by possible variations in its position and intensity. (Author) 4 refs

  5. Radon anomalies prior to earthquakes (1). Review of previous studies

    International Nuclear Information System (INIS)

    Ishikawa, Tetsuo; Tokonami, Shinji; Yasuoka, Yumi; Shinogi, Masaki; Nagahama, Hiroyuki; Omori, Yasutaka; Kawada, Yusuke

    2008-01-01

    The relationship between radon anomalies and earthquakes has been studied for more than 30 years. However, most of the studies dealt with radon in soil gas or in groundwater. Before the 1995 Hyogoken-Nanbu earthquake, an anomalous increase of atmospheric radon was observed at Kobe Pharmaceutical University. The increase was well fitted with a mathematical model related to earthquake fault dynamics. This paper reports the significance of this observation, reviewing previous studies on radon anomaly before earthquakes. Groundwater/soil radon measurements for earthquake prediction began in 1970's in Japan as well as foreign countries. One of the most famous studies in Japan is groundwater radon anomaly before the 1978 Izu-Oshima-kinkai earthquake. We have recognized the significance of radon in earthquake prediction research, but recently its limitation was also pointed out. Some researchers are looking for a better indicator for precursors; simultaneous measurements of radon and other gases are new trials in recent studies. Contrary to soil/groundwater radon, we have not paid much attention to atmospheric radon before earthquakes. However, it might be possible to detect precursors in atmospheric radon before a large earthquake. In the next issues, we will discuss the details of the anomalous atmospheric radon data observed before the Hyogoken-Nanbu earthquake. (author)

  6. Dipendenza-Indipendenza dal Campo e Linguaggio Scritto: Uno Studio su Gruppi di Studenti di Scuola Media Superiore (Field Dependence-Field Independence and the Written Language: A Study of Groups of Senior High School Students).

    Science.gov (United States)

    Cappelletto, Anna Maria

    1995-01-01

    This article describes research carried out with 389 Italian senior high school students to test the hypothesis that there is a relationship between one's written language and cognitive style. This study takes previous research in the area of field dependence and field independence in a new direction. (CFM)

  7. Analysis of previous perceptual and motor experience in breaststroke kick learning

    Directory of Open Access Journals (Sweden)

    Ried Bettina

    2015-12-01

    Full Text Available One of the variables that influence motor learning is the learner’s previous experience, which may provide perceptual and motor elements to be transferred to a novel motor skill. For swimming skills, several motor experiences may prove effective. Purpose. The aim was to analyse the influence of previous experience in playing in water, swimming lessons, and music or dance lessons on learning the breaststroke kick. Methods. The study involved 39 Physical Education students possessing basic swimming skills, but not the breaststroke, who performed 400 acquisition trials followed by 50 retention and 50 transfer trials, during which stroke index as well as rhythmic and spatial configuration indices were mapped, and answered a yes/no questionnaire regarding previous experience. Data were analysed by ANOVA (p = 0.05 and the effect size (Cohen’s d ≥0.8 indicating large effect size. Results. The whole sample improved their stroke index and spatial configuration index, but not their rhythmic configuration index. Although differences between groups were not significant, two types of experience showed large practical effects on learning: childhood water playing experience only showed major practically relevant positive effects, and no experience in any of the three fields hampered the learning process. Conclusions. The results point towards diverse impact of previous experience regarding rhythmic activities, swimming lessons, and especially with playing in water during childhood, on learning the breaststroke kick.

  8. Raman study of electronic excitations in MgB2 with application of high magnetic field

    International Nuclear Information System (INIS)

    Machtoub, L.; Takano, Y.; Kito, H.

    2006-01-01

    We present the first results of Raman scattering with application of magnetic field on magnesium diboride (MgB 2 ). In this work, we have investigated the magnetic field dependence of the 72 meV (E 2g mode) and the pair-breaking peak around 100 cm -1 which corresponds to σ-band gap. Intensity enhancement of Raman features around 800 cm -1 accompanied with broadening in the line shape of E 2g mode has been observed in some polycrystalline samples at 0 GPa. Results are compared with previous Raman study under hydrostatic pressure

  9. Technical Note: Response measurement for select radiation detectors in magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, M., E-mail: michaelreynolds@ualberta.net [Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Fallone, B. G. [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada and Departments of Oncology and Physics, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Rathee, S. [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada and Department of Oncology, Medical Physics Division,University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada)

    2015-06-15

    Purpose: Dose response to applied magnetic fields for ion chambers and solid state detectors has been investigated previously for the anticipated use in linear accelerator–magnetic resonance devices. In this investigation, the authors present the measured response of selected radiation detectors when the magnetic field is applied in the same direction as the radiation beam, i.e., a longitudinal magnetic field, to verify previous simulation only data. Methods: The dose response of a PR06C ion chamber, PTW60003 diamond detector, and IBA PFD diode detector is measured in a longitudinal magnetic field. The detectors are irradiated with buildup caps and their long axes either parallel or perpendicular to the incident photon beam. In each case, the magnetic field dose response is reported as the ratio of detector signals with to that without an applied longitudinal magnetic field. The magnetic field dose response for each unique orientation as a function of magnetic field strength was then compared to the previous simulation only studies. Results: The measured dose response of each detector in longitudinal magnetic fields shows no discernable response up to near 0.21 T. This result was expected and matches the previously published simulation only results, showing no appreciable dose response with magnetic field. Conclusions: Low field longitudinal magnetic fields have been shown to have little or no effect on the dose response of the detectors investigated and further lend credibility to previous simulation only studies.

  10. A MULTIWAVELENGTH STUDY OF TADPOLE GALAXIES IN THE HUBBLE ULTRA DEEP FIELD

    International Nuclear Information System (INIS)

    Straughn, Amber N.; Eufrasio, Rafael T.; Gardner, Jonathan P.; Voyer, Elysse N.; Mello, Duilia de; Soto, Emmaris; Petty, Sara; Kassin, Susan; Ravindranath, Swara

    2015-01-01

    Multiwavelength data are essential in order to provide a complete picture of galaxy evolution and to inform studies of galaxies’ morphological properties across cosmic time. Here we present the results of a multiwavelength investigation of the morphologies of “tadpole” galaxies at intermediate redshift (0.314 < z < 3.175) in the Hubble Ultra Deep Field. These galaxies were previously selected from deep Hubble Space Telescope (HST) F775W data based on their distinct asymmetric knot-plus-tail morphologies. Here we use deep Wide Field Camera 3 near-infrared imaging in addition to the HST optical data in order to study the rest-frame UV/optical morphologies of these galaxies across the redshift range 0.3 < z < 3.2. This study reveals that the majority of these galaxies do retain their general asymmetric morphology in the rest-frame optical over this redshift range, if not the distinct “tadpole” shape. The average stellar mass of tadpole galaxies is lower than that of field galaxies, with the effect being slightly greater at higher redshift within the errors. Estimated from spectral energy distribution fits, the average age of tadpole galaxies is younger than that of field galaxies in the lower-redshift bin, and the average metallicity is lower (whereas the specific star formation rate for tadpoles is roughly the same as field galaxies across the redshift range probed here). These average effects combined support the conclusion that this subset of galaxies is in an active phase of assembly, either late-stage merging or cold gas accretion causing localized clumpy star formation

  11. A MULTIWAVELENGTH STUDY OF TADPOLE GALAXIES IN THE HUBBLE ULTRA DEEP FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Straughn, Amber N.; Eufrasio, Rafael T.; Gardner, Jonathan P. [Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Voyer, Elysse N. [Randstad at Google, 1129 San Antonio Road, Palo Alto, CA (United States); Mello, Duilia de; Soto, Emmaris [Department of Physics, The Catholic University of America, Washington, DC 20064 (United States); Petty, Sara [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Kassin, Susan; Ravindranath, Swara [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2015-12-01

    Multiwavelength data are essential in order to provide a complete picture of galaxy evolution and to inform studies of galaxies’ morphological properties across cosmic time. Here we present the results of a multiwavelength investigation of the morphologies of “tadpole” galaxies at intermediate redshift (0.314 < z < 3.175) in the Hubble Ultra Deep Field. These galaxies were previously selected from deep Hubble Space Telescope (HST) F775W data based on their distinct asymmetric knot-plus-tail morphologies. Here we use deep Wide Field Camera 3 near-infrared imaging in addition to the HST optical data in order to study the rest-frame UV/optical morphologies of these galaxies across the redshift range 0.3 < z < 3.2. This study reveals that the majority of these galaxies do retain their general asymmetric morphology in the rest-frame optical over this redshift range, if not the distinct “tadpole” shape. The average stellar mass of tadpole galaxies is lower than that of field galaxies, with the effect being slightly greater at higher redshift within the errors. Estimated from spectral energy distribution fits, the average age of tadpole galaxies is younger than that of field galaxies in the lower-redshift bin, and the average metallicity is lower (whereas the specific star formation rate for tadpoles is roughly the same as field galaxies across the redshift range probed here). These average effects combined support the conclusion that this subset of galaxies is in an active phase of assembly, either late-stage merging or cold gas accretion causing localized clumpy star formation.

  12. Simulation study of solar plasma eruptions caused by interactions between emerging flux and coronal arcade fields

    International Nuclear Information System (INIS)

    Kaneko, Takafumi; Yokoyama, Takaaki

    2014-01-01

    We investigate the triggering mechanisms of plasma eruptions in the solar atmosphere due to interactions between emerging flux and coronal arcade fields by using two-dimensional MHD simulations. We perform parameter surveys with respect to arcade field height, magnetic field strength, and emerging flux location. Our results show that two possible mechanisms exist, and which mechanism is dominant depends mostly on emerging flux location. One mechanism appears when the location of emerging flux is close to the polarity inversion line (PIL) of an arcade field. This mechanism requires reconnection between the emerging flux and the arcade field, as pointed out by previous studies. The other mechanism appears when the location of emerging flux is around the edge of an arcade field. This mechanism does not require reconnection between the emerging flux and the arcade field but does demand reconnection in the arcade field above the PIL. Furthermore, we found that the eruptive condition for this mechanism can be represented by a simple formula.

  13. Summary of Previous Chamber or Controlled Anthrax Studies and Recommendations for Possible Additional Studies

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, Gregory F.; Amidan, Brett G.; Morrow, Jayne B.

    2010-12-29

    This report and an associated Excel file(a) summarizes the investigations and results of previous chamber and controlled studies(b) to characterize the performance of methods for collecting, storing and/or transporting, extracting, and analyzing samples from surfaces contaminated by Bacillus anthracis (BA) or related simulants. This report and the Excel are the joint work of the Pacific Northwest National Laboratory (PNNL) and the National Institute of Standards and Technology (NIST) for the Department of Homeland Security, Science and Technology Directorate. The report was originally released as PNNL-SA-69338, Rev. 0 in November 2009 with limited distribution, but was subsequently cleared for release with unlimited distribution in this Rev. 1. Only minor changes were made to Rev. 0 to yield Rev. 1. A more substantial update (including summarizing data from other studies and more condensed summary tables of data) is underway

  14. An fMRI study of neuronal activation in schizophrenia patients with and without previous cannabis use

    Directory of Open Access Journals (Sweden)

    Else-Marie eLøberg

    2012-10-01

    Full Text Available Previous studies have mostly shown positive effects of cannabis use on cognition in patients with schizophrenia, which could reflect lower neurocognitive vulnerability. There are however no studies comparing whether such cognitive differences have neuronal correlates. Thus, the aim of the present study was to compare whether patients with previous cannabis use differ in brain activation from patients who has never used cannabis. The patients groups were compared on the ability to up-regulate an effort mode network during a cognitive task and down-regulate activation in the same network during a task-absent condition. Task-present and task-absent brain activation was measured by functional magnetic resonance neuroimaging (fMRI. Twenty-six patients with a DSM-IV and ICD-10 diagnosis of schizophrenia were grouped into a previous cannabis user group and a no-cannabis group. An auditory dichotic listening task with instructions of attention focus on either the right or left ear stimulus was used to tap verbal processing, attention and cognitive control, calculated as an aggregate score. When comparing the two groups, there were remaining activations in the task-present condition for the cannabis group, not seen in the no-cannabis group, while there was remaining activation in the task-absent condition for the no-cannabis group, not seen in the cannabis group. Thus, the patients with previous cannabis use showed increased activation in an effort mode network and decreased activation in the default mode network as compared to the no-cannabis group. It is concluded that the present study show some differences in brain activation to a cognitively challenging task between previous cannabis and no-cannabis schizophrenia patients.

  15. Laparoscopy After Previous Laparotomy

    Directory of Open Access Journals (Sweden)

    Zulfo Godinjak

    2006-11-01

    Full Text Available Following the abdominal surgery, extensive adhesions often occur and they can cause difficulties during laparoscopic operations. However, previous laparotomy is not considered to be a contraindication for laparoscopy. The aim of this study is to present that an insertion of Veres needle in the region of umbilicus is a safe method for creating a pneumoperitoneum for laparoscopic operations after previous laparotomy. In the last three years, we have performed 144 laparoscopic operations in patients that previously underwent one or two laparotomies. Pathology of digestive system, genital organs, Cesarean Section or abdominal war injuries were the most common causes of previouslaparotomy. During those operations or during entering into abdominal cavity we have not experienced any complications, while in 7 patients we performed conversion to laparotomy following the diagnostic laparoscopy. In all patients an insertion of Veres needle and trocar insertion in the umbilical region was performed, namely a technique of closed laparoscopy. Not even in one patient adhesions in the region of umbilicus were found, and no abdominal organs were injured.

  16. Data from studies of previous radioactive waste disposal in Massachusetts Bay

    International Nuclear Information System (INIS)

    Curtis, W.R.; Mardis, H.M.

    1984-12-01

    This report presents the results of studies conducted in Massachusetts Bay during 1981 and 1982. Included are data from: (1) a side scan sonar survey of disposal areas in the Bay that was carried out by the National Oceanic and Atmospheric Administration (NOAA) for EPA; (2) Collections of sediment and biota by NOAA for radiochemical analysis by EPA; (3) collections of marketplace seafood samples by the Food and Drug Administration (FDA) for radioanalysis by both FDA and EPA; and (4) a radiological monitoring survey of LLW disposal areas by EPA to determine whether there should be any concern for public health resulting from previous LLW disposals in the Bay

  17. Medical terminology across the centuries: distinctive features of a chronological study in the field of ophthalmology

    Directory of Open Access Journals (Sweden)

    María José Esteve Ramos

    2006-10-01

    Full Text Available This article deals with the comparison of the lexical features of two texts from a diachronic point of view. Interest in lexical comparison arises from the fact that the two texts belong to a specialised field within medicine –ophthalmology– and both can be considered of the same genre. The linguistic analysis focuses on morphological and etymological aspects, based on previous studies with a historical perspective in the field of medicine (Norri, 1992. As a result of the study, different implications concerning the use of words from the Germanic native stock or from other sources, together with the different social and scientific changes, are shown in this article.

  18. Personality and field of study choice

    NARCIS (Netherlands)

    Humburg, M.

    2014-01-01

    Field of study choice has far-reaching implications for individuals enrolling in university. Field of study choice is strongly linked to the subject matter graduates will specialize in, the kind of work environment they will be working in, and the returns to their skills they can expect once they

  19. Study of the electric Held in HTS tape caused by perpendicular AC magnetic field

    International Nuclear Information System (INIS)

    Roiberg, V; Kopansky, F.

    2004-01-01

    Full Text: In a previous work we studied the influence of AC magnetic fields on voltage-currents (V-I) characteristics of high temperature superconducting (HTS) multi filament BSCC0-2223 tapes. It was found that AC magnetic fields perpendicular to the ab plane (the wide surface of the tape) cause a linear decrease of the critical current (IC) with amplitude of the AC magnetic field. The degradation of IC in .AC field was explained by the geometrical model according to which the transport current floe: is confined to the central zone of the tape where .AC field does not penetrate. For deeper understanding of the observed phenomena we carried out a study of the time dependence of the electric field during the cycle of AC field. At the same time we expanded the frequency range to low frequencies down to 1 Hz. The main results of the work are as following. 1. The time modulation of the electric field E in the HTS tape carrying transport DC current has the double frequency relating to AC magnetic field. 2. In field amplitudes less than 70 G the electric field modulation decreases with increasing frequency in opposite to its well-pronounced increase in higher AC field amplitudes. Alcove 70 G, the electric field increases with increasing the frequency of the external magnetic field. The wave forms of the electric field are different in both amplitudes ranges. 3. E-I curves of the tape in low amplitudes are frequency independent and coincide with E-l curves in AC field with intensity equal to the AC field amplitude. 4. In high AC field amplitudes, a strong dependence of the E-I curves on frequency is observed in the frequency range of 1-40 Hz and no dependence is observed in higher frequencies. Our results suggest that a combination of the geometrical model with flux creep concepts is necessary for a better understanding of the electric field behavior in our measurement conditions

  20. Whole-Home Dehumidifiers: Field-Monitoring Study

    Energy Technology Data Exchange (ETDEWEB)

    Burke, Tom; Willem, Henry; Ni, Chun Chun; Stratton, Hannah; Whitehead, Camilla Dunham; Johnson, Russell

    2014-09-23

    Lawrence Berkeley National Laboratory (LBNL) initiated a WHD field-metering study to expand current knowledge of and obtain data on WHD operation and energy consumption in real-world applications. The field study collected real-time data on WHD energy consumption, along with information regarding housing characteristics, consumer behavior, and various outdoor conditions expected to affect WHD performance and efficiency. Although the metering study collected similar data regarding air conditioner operation, this report discusses only WHDs. The primary objectives of the LBNL field-metering study are to (1) expand knowledge of the configurations, energy consumption profiles, consumer patterns of use (e.g., relative humidity [RH] settings), and environmental parameters of whole-home dehumidification systems; and (2) develop distributions of hours of dehumidifier operation in four operating modes: off, standby, fan-only, and compressor (also called dehumidification mode). Profiling energy consumption entails documenting the power consumption, duration of power consumption in different modes, condensate generation, and properties of output air of an installed system under field conditions of varying inlet air temperature and RH, as well as system configuration. This profiling provides a more detailed and deeper understanding of WHD operation and its complexities. This report describes LBNL’s whole-home dehumidification field-metering study conducted at four homes in Wisconsin and Florida. The initial phase of the WHD field-metering study was conducted on one home in Madison, Wisconsin, from June to December of 2013. During a second phase, three Florida homes were metered from June to October of 2014. This report presents and examines data from the Wisconsin site and from the three Florida sites.

  1. Photon Splitting in a Strong Magnetic Field: Recalculation and Comparison with Previous Calculations

    International Nuclear Information System (INIS)

    Adler, S.L.; Schubert, C.

    1996-01-01

    We recalculate the amplitude for photon splitting in a strong magnetic field below the pair production threshold, using the world line path integral variant of the Bern-Kosower formalism. Numerical comparison (using programs that we have made available for public access on the Internet) shows that the results of the recalculation are identical to the earlier calculations of Adler and later of Stoneham, and to the recent recalculation by Baier, Milstein, and Shaisultanov. copyright 1996 The American Physical Society

  2. Pulsed field studies of magnetotransport in semiconductor heterostructures

    International Nuclear Information System (INIS)

    Dalton, K.S.H.

    1999-01-01

    High field magnetotransport in two classes of semiconductor heterostructures has been studied: parallel transport in InAs/(Ga,In)Sb double heterojunctions and superlattices at low temperatures (300 mK-4.2 K), and vertical transport in GaAs/AlAs short-period superlattices at 150-300 K. The experiments mainly used the Oxford pulsed magnet (∼45 T, ∼15 ms pulses). The development of the data acquisition system and experimental techniques for magnetotransport are described, including corrections to the data, required because of the rapidly changing magnetic field. Previous studies of magnetotransport in InAs/GaSb double heterojunctions are reviewed: this electron-hole system shows compensated quantum Hall plateaux, with ρ xy dips accompanied by 'anomalous' peaks in σ xx . New data show a peak between ν=1 plateaux; this behaviour and the temperature dependence of the 'anomalous' σ xx peaks are explained by considering the movement of the Fermi level amongst anticrossing electron- and hole-like levels. InAs/(Ga,In)Sb superlattices with electron:hole density ratios close to 1 exhibit large oscillations in the resistivity (maxima typically ∼20-30 x higher than minima) and conductivity components. Deep minima in ρ xy alternate with low-integer plateaux. The magnetotransport in various ideal structures is considered, to explain the experimental results. The growth of a novel structure has allowed clearer observation of the behaviour of ρ xx (giant maxima) and ρ xy (zeroes or maxima) when the contributions from each well to σ xx and σ xy approach zero. Measurements of the high field magnetotransport peak positions show that the band overlap is increased by growing 'InSb' rather than 'GaAs' interfaces (∼20% increase), increasing the indium in the (Ga,In)Sb (∼30% increase per 10% In), or growing along [111] instead of [001] (∼30% increase). Magnetophonon resonance in short-period GaAs/AlAs superlattices causes strong, electric field-dependent vertical

  3. Critical study of the dispersive n- 90Zr mean field by means of a new variational method

    Science.gov (United States)

    Mahaux, C.; Sartor, R.

    1994-02-01

    A new variational method is developed for the construction of the dispersive nucleon-nucleus mean field at negative and positive energies. Like the variational moment approach that we had previously proposed, the new method only uses phenomenological optical-model potentials as input. It is simpler and more flexible than the previous approach. It is applied to a critical investigation of the n- 90Zr mean field between -25 and +25 MeV. This system is of particular interest because conflicting results had recently been obtained by two different groups. While the imaginary parts of the phenomenological optical-model potentials provided by these two groups are similar, their real parts are quite different. Nevertheless, we demonstrate that these two sets of phenomenological optical-model potentials are both compatible with the dispersion relation which connects the real and imaginary parts of the mean field. Previous hints to the contrary, by one of the two other groups, are shown to be due to unjustified approximations. A striking outcome of the present study is that it is important to explicitly introduce volume absorption in the dispersion relation, although volume absorption is negligible in the energy domain investigated here. Because of the existence of two sets of phenomenological optical-model potentials, our variational method yields two dispersive mean fields whose real parts are quite different at small or negative energies. No preference for one of the two dispersive mean fields can be expressed on purely empirical grounds since they both yield fair agreement with the experimental cross sections as well as with the observed energies of the bound single-particle states. However, we argue that one of these two mean fields is physically more meaningful, because the radial shape of its Hartree-Fock type component is independent of energy, as expected on theoretical grounds. This preferred mean field is very close to the one which had been obtained by the Ohio

  4. Pilot study for the implantation of a high-energy neutrons field

    International Nuclear Information System (INIS)

    Pinto, Jose Julio de O.; Mendes, Adriane C.; Federico, Claudio A.; Passaro, Angelo; Gaspar, Felipe de B.; Pazianotto, Mauricio T.

    2013-01-01

    In this work a theoretical study is presented for the implementation of a high-energy neutron field (14.1 MeV) produced by a neutron generator type DT (deuterium-tritium), to be installed in the premises of the Laboratorio de Radiacoes Ionizantes (LRI) of the Instituto de Estudos Avancados (IEAv). This evaluation was performed by means of computer simulation by Monte Carlo method, using the computer code MCNP5 (Monte Carlo N-Particle). The neutron spectra were simulated computationally for pre-selected points of the installation, allowing to estimate the beam quality in the positions provided for use of the direct beam. These simulations also allow assist the basement of a project to install the consistent D-T generator with the guidelines for radiation protection and radiation safety standards determined by the Comissao Nacional de Energia Nuclear (CNEN), by estimating the dose rates provided in accessible points to Individuals Occupationally Exposed (IOE) in the facility. The computational determination of spectra, fluxes and doses produced in different positions previously selected within and outside the laboratory, will serve as guidance from previous studies for the future installation of this generator in the physical facilities of the LRI

  5. Preoperative screening: value of previous tests.

    Science.gov (United States)

    Macpherson, D S; Snow, R; Lofgren, R P

    1990-12-15

    To determine the frequency of tests done in the year before elective surgery that might substitute for preoperative screening tests and to determine the frequency of test results that change from a normal value to a value likely to alter perioperative management. Retrospective cohort analysis of computerized laboratory data (complete blood count, sodium, potassium, and creatinine levels, prothrombin time, and partial thromboplastin time). Urban tertiary care Veterans Affairs Hospital. Consecutive sample of 1109 patients who had elective surgery in 1988. At admission, 7549 preoperative tests were done, 47% of which duplicated tests performed in the previous year. Of 3096 previous results that were normal as defined by hospital reference range and done closest to the time of but before admission (median interval, 2 months), 13 (0.4%; 95% CI, 0.2% to 0.7%), repeat values were outside a range considered acceptable for surgery. Most of the abnormalities were predictable from the patient's history, and most were not noted in the medical record. Of 461 previous tests that were abnormal, 78 (17%; CI, 13% to 20%) repeat values at admission were outside a range considered acceptable for surgery (P less than 0.001, frequency of clinically important abnormalities of patients with normal previous results with those with abnormal previous results). Physicians evaluating patients preoperatively could safely substitute the previous test results analyzed in this study for preoperative screening tests if the previous tests are normal and no obvious indication for retesting is present.

  6. Satellite-borne study of seismic phenomena by low frequency magnetic field observations

    Science.gov (United States)

    Schwingenschuh, Konrad; Magnes, Werner; Xuhui, Shen; Wang, Jindong; Pollinger, Andreas; Hagen, Christian; Prattes, Gustav; Eichelberger, Hans-Ulrich; Wolbang, Daniel; Boudjada, Mohammed Y.; Besser, Bruno P.; Rozhnoi, Alexander A.; Zhang, Tielong

    2015-04-01

    A combined scalar-vector magnetic field experiment will be flown on the upcoming CSES mission (China Seismo-Electromagnetic Satellite). Magnetic field data from DC to 30 Hz will be measured with an accuracy of about 10 pT. A fluxgate instrument will provide the 3 magnetic field components and a new type of an optically pumped magnetometer [see Pollinger, 2010] will measure the magnitude of the ambient magnetic field. The satellite will operate in a Sun synchronous polar orbit at an altitude of about 500 km and with an inclination of 97°. We present a model of magnetic field fluctuations in the upper ionosphere based on previous satellite observations and on a model of the lithospheric-atmospheric-ionospheric coupling. Pollinger et al., CDSM-a new scalar magnetometer, EGU General Assembly 2010

  7. [Studies in quantum field theory

    International Nuclear Information System (INIS)

    1990-01-01

    During the period 4/1/89--3/31/90 the theoretical physics group supported by Department of Energy Contract No. AC02-78ER04915.A015 and consisting of Professors Bender and Shrauner, Associate Professor Papanicolaou, Assistant Professor Ogilvie, and Senior Research Associate Visser has made progress in many areas of theoretical and mathematical physics. Professors Bender and Shrauner, Associate Professor Papanicolaou, Assistant Professor Ogilvie, and Research Associate Visser are currently conducting research in many areas of high energy theoretical and mathematical physics. These areas include: strong-coupling approximation; classical solutions of non-Abelian gauge theories; mean-field approximation in quantum field theory; path integral and coherent state representations in quantum field theory; lattice gauge calculations; the nature of perturbation theory in large order; quark condensation in QCD; chiral symmetry breaking; the 1/N expansion in quantum field theory; effective potential and action in quantum field theories, including OCD; studies of the early universe and inflation, and quantum gravity

  8. Field studies of HT oxidation and dispersion in the environment. I

    International Nuclear Information System (INIS)

    Brown, R.M.

    1987-01-01

    The environmental dispersion and oxidation of a controlled atmospheric release of tritiated hydrogen (HT) was studied in a pilot-scale field experiment. This study was designed to test procedures and obtain preliminary results for planning a more intensive experiment to determine the environmental behaviour of HT with emphasis on the processes leading to the appearance of HTO in the atmosphere, ie., conversion, deposition and resuspension. Field observations led to the following conclusions: 1) no evidence was found for the rapid conversion of HT to HTO in the atmosphere, 2) observations support the hypothesis that the dominant process giving rise to the observed HTO in air was HT oxidation in the soil by microbial action followed by resuspension of HTO, 3) HT deposition velocities to soil ranged between 0.041 cm/s and 0.13 cm/s, consistent with previous chamber measurements, 4) the rate of HTO loss from soil, averaged over 21 days, was less than 1% per hour, and 5) vegetation HTO concentrations initially increased with time then by 48 hours decreased exponentially at a rate similar to soils. These results will be validated and extended by the intensive experiment scheduled for June, 1987

  9. Field studies courses open

    Science.gov (United States)

    Fourteen month-long courses combining applied academics with training in field research methodology are being offered this summer by the School for Field Studies. The courses, held in eight countries during May, June, July, and August, provide unique opportunities for participants to work as a team under primitive conditions.‘Our courses bind together the academic challenge of the research problem, the physical challenge of the site itself, and the interpersonal challenge of the expedition team in a dynamic way so that both cognitive and affective learning are accelerated,’ according to Jim Elder, the school's director.

  10. Towards accurate simulation of fringe field effects

    International Nuclear Information System (INIS)

    Berz, M.; Erdelyi, B.; Makino, K.

    2001-01-01

    In this paper, we study various fringe field effects. Previously, we showed the large impact that fringe fields can have on certain lattice scenarios of the proposed Neutrino Factory. Besides the linear design of the lattice, the effects depend strongly on the details of the field fall off. Various scenarios are compared. Furthermore, in the absence of detailed information, we study the effects for the LHC, a case where the fringe fields are known, and try to draw some conclusions for Neutrino Factory lattices

  11. Visual Field Asymmetry in Attentional Capture

    Science.gov (United States)

    Du, Feng; Abrams, Richard A.

    2010-01-01

    The present study examined the spatial distribution of involuntary attentional capture over the two visual hemi-fields. A new experiment, and an analysis of three previous experiments showed that distractors in the left visual field that matched a sought-for target in color produced a much larger capture effect than identical distractors in the…

  12. Two field formulation of closed string field theory

    International Nuclear Information System (INIS)

    Bogojevic, A.R.

    1990-09-01

    A formulation of closed string field theory is presented that is based on a two field action. It represents a generalization of Witten's Chern-Simons formulation of 3d gravity. The action contains only 3 string interactions and no string field truncations, unlike the previous non-polynomial action of Zwiebach. The two field action is found to follow from a purely cubic, background independent action similar to the one for open strings. (orig.)

  13. Four Forensic Entomology Case Studies: Records and Behavioral Observations on Seldom Reported Cadaver Fauna With Notes on Relevant Previous Occurrences and Ecology.

    Science.gov (United States)

    Lindgren, Natalie K; Sisson, Melissa S; Archambeault, Alan D; Rahlwes, Brent C; Willett, James R; Bucheli, Sibyl R

    2015-03-01

    A yearlong survey of insect taxa associated with human decomposition was conducted at the Southeast Texas Applied Forensic Science (STAFS) facility located in the Center for Biological Field Studies of Sam Houston State University in Huntsville, TX. During this study, four insect-cadaver interactions were observed that represent previously poorly documented yet forensically significant interactions: Syrphidae maggots colonized a corpse in an aquatic situation; Psychodidae adults mated and oviposited on an algal film that was present on a corpse that had been recently removed from water; several Panorpidae were the first insects to feed upon a freshly placed corpse in the autumn; and a noctuid caterpillar was found chewing and ingesting dried human skin. Baseline knowledge of insect-cadaver interactions is the foundation of forensic entomology, and unique observations have the potential to expand our understanding of decomposition ecology. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  14. Study on the system development for evaluating long-term alteration of hydraulic field in Near Field 2

    International Nuclear Information System (INIS)

    Okutu, Kazuo; Morikawa, Seiji; Takamura, Hisashi

    2003-02-01

    influence of rock behavior in this dynamic alteration action analysis system, several previous research reports were examined. And the influence of rock creep on permeability was estimated. This estimation result indicated that the external force assumed in previous report (TRU report 2000) have no influence, but under the condition to which the rock creep tends to progress, it have possibilities of causing significant influence. 3) The coupled chemical-hydraulic analysis system and the mechanical analysis system were further coupled for the coupled analysis of Near Field evolution. The solution algorithm for the coupled analysis was investigated. (author)

  15. Risk assessment of electromagnetic fields exposure with metallic orthopedic implants: a cadaveric study.

    Science.gov (United States)

    Crouzier, D; Selek, L; Martz, B-A; Dabouis, V; Arnaud, R; Debouzy, J-C

    2012-02-01

    Metallic materials are well known to strongly interact with electromagnetic fields. While biological effects of such field have been extensively studied, only few works dealt with the interactions of electromagnetic waves with passive metallic device implanted in biological system. Hence only several numerical and phantom simulation studies were focusing on this aspect, whereas no in situ anatomic experiment has been previously performed. In this study the effect of electromagnetic waves on eight different orthopaedic medical devices (six plates from 55 to 318mm length, a total knee and a total hip prosthesis) were explored on six human cadavers. To mimic a random environmental exposure resulting from the most common frequencies band used in domestic environment and medical applications (TV and radio broadcasting, cell phone communication, MRI, diathermy treatment), a multifrequency generator emitting in VHF, UHF, GSM and GCS frequency bands was used. The different medical devices were exposed to an electromagnetic field at 50W/m(2) and 100W/m(2). After 6min exposure, the temperature was measured on three points close to each medical device, and the induced currents were estimated. No significant temperature increase (<0.2°C) was finally detected; beside, a slight induced tension (up to 1.1V) was recorded but would appear too low to induce any biological side effect. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  16. Multi-valued fields

    CERN Document Server

    Ershov, Yuri L

    2001-01-01

    For more than 30 years, the author has studied the model-theoretic aspects of the theory of valued fields and multi-valued fields. Many of the key results included in this book were obtained by the author whilst preparing the manuscript. Thus the unique overview of the theory, as developed in the book, has been previously unavailable. The book deals with the theory of valued fields and mutli-valued fields. The theory of Prüfer rings is discussed from the `geometric' point of view. The author shows that by introducing the Zariski topology on families of valuation rings, it is possible to distinguish two important subfamilies of Prüfer rings that correspond to Boolean and near Boolean families of valuation rings. Also, algebraic and model-theoretic properties of multi-valued fields with near Boolean families of valuation rings satisfying the local-global principle are studied. It is important that this principle is elementary, i.e., it can be expressed in the language of predicate calculus. The most important...

  17. Estimating the effect of current, previous and never use of drugs in studies based on prescription registries

    DEFF Research Database (Denmark)

    Nielsen, Lars Hougaard; Løkkegaard, Ellen; Andreasen, Anne Helms

    2009-01-01

    of this misclassification for analysing the risk of breast cancer. MATERIALS AND METHODS: Prescription data were obtained from Danish Registry of Medicinal Products Statistics and we applied various methods to approximate treatment episodes. We analysed the duration of HT episodes to study the ability to identify......PURPOSE: Many studies which investigate the effect of drugs categorize the exposure variable into never, current, and previous use of the study drug. When prescription registries are used to make this categorization, the exposure variable possibly gets misclassified since the registries do...... not carry any information on the time of discontinuation of treatment.In this study, we investigated the amount of misclassification of exposure (never, current, previous use) to hormone therapy (HT) when the exposure variable was based on prescription data. Furthermore, we evaluated the significance...

  18. ACCOUNTING FOR COSMIC VARIANCE IN STUDIES OF GRAVITATIONALLY LENSED HIGH-REDSHIFT GALAXIES IN THE HUBBLE FRONTIER FIELD CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Brant E.; Stark, Dan P. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Ellis, Richard S. [Department of Astronomy, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Dunlop, James S.; McLure, Ross J.; McLeod, Derek, E-mail: brant@email.arizona.edu [Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ (United Kingdom)

    2014-12-01

    Strong gravitational lensing provides a powerful means for studying faint galaxies in the distant universe. By magnifying the apparent brightness of background sources, massive clusters enable the detection of galaxies fainter than the usual sensitivity limit for blank fields. However, this gain in effective sensitivity comes at the cost of a reduced survey volume and, in this Letter, we demonstrate that there is an associated increase in the cosmic variance uncertainty. As an example, we show that the cosmic variance uncertainty of the high-redshift population viewed through the Hubble Space Telescope Frontier Field cluster Abell 2744 increases from ∼35% at redshift z ∼ 7 to ≳ 65% at z ∼ 10. Previous studies of high-redshift galaxies identified in the Frontier Fields have underestimated the cosmic variance uncertainty that will affect the ultimate constraints on both the faint-end slope of the high-redshift luminosity function and the cosmic star formation rate density, key goals of the Frontier Field program.

  19. ACCOUNTING FOR COSMIC VARIANCE IN STUDIES OF GRAVITATIONALLY LENSED HIGH-REDSHIFT GALAXIES IN THE HUBBLE FRONTIER FIELD CLUSTERS

    International Nuclear Information System (INIS)

    Robertson, Brant E.; Stark, Dan P.; Ellis, Richard S.; Dunlop, James S.; McLure, Ross J.; McLeod, Derek

    2014-01-01

    Strong gravitational lensing provides a powerful means for studying faint galaxies in the distant universe. By magnifying the apparent brightness of background sources, massive clusters enable the detection of galaxies fainter than the usual sensitivity limit for blank fields. However, this gain in effective sensitivity comes at the cost of a reduced survey volume and, in this Letter, we demonstrate that there is an associated increase in the cosmic variance uncertainty. As an example, we show that the cosmic variance uncertainty of the high-redshift population viewed through the Hubble Space Telescope Frontier Field cluster Abell 2744 increases from ∼35% at redshift z ∼ 7 to ≳ 65% at z ∼ 10. Previous studies of high-redshift galaxies identified in the Frontier Fields have underestimated the cosmic variance uncertainty that will affect the ultimate constraints on both the faint-end slope of the high-redshift luminosity function and the cosmic star formation rate density, key goals of the Frontier Field program

  20. Accounting for Cosmic Variance in Studies of Gravitationally Lensed High-redshift Galaxies in the Hubble Frontier Field Clusters

    Science.gov (United States)

    Robertson, Brant E.; Ellis, Richard S.; Dunlop, James S.; McLure, Ross J.; Stark, Dan P.; McLeod, Derek

    2014-12-01

    Strong gravitational lensing provides a powerful means for studying faint galaxies in the distant universe. By magnifying the apparent brightness of background sources, massive clusters enable the detection of galaxies fainter than the usual sensitivity limit for blank fields. However, this gain in effective sensitivity comes at the cost of a reduced survey volume and, in this Letter, we demonstrate that there is an associated increase in the cosmic variance uncertainty. As an example, we show that the cosmic variance uncertainty of the high-redshift population viewed through the Hubble Space Telescope Frontier Field cluster Abell 2744 increases from ~35% at redshift z ~ 7 to >~ 65% at z ~ 10. Previous studies of high-redshift galaxies identified in the Frontier Fields have underestimated the cosmic variance uncertainty that will affect the ultimate constraints on both the faint-end slope of the high-redshift luminosity function and the cosmic star formation rate density, key goals of the Frontier Field program.

  1. Using Case Studies to Enrich Field Experience.

    Science.gov (United States)

    Florio-Ruane, Susan; Clark, Christopher M.

    1990-01-01

    This paper discusses the use of field experience in teacher education and how it can be augmented by phenomenological case studies. It summarizes a particular case study involving three teacher education classes, noting that reflective analysis of cases can prepare students to observe in the field. (SM)

  2. GLOBE Aerosol Field Campaign - U.S. Pilot Study 2016

    Science.gov (United States)

    Pippin, Margaret; Marentette, Christina; Bujosa, Robert; Taylor, Jessica; Lewis, Preston

    2016-01-01

    During the spring of 2016, from April 4 - May 27, sixteen GLOBE schools participated in the GLOBE Aerosol Field Campaign - U.S. Pilot Study. Thirteen teachers from these schools had previously participated in the NASA LEARN program (Long-term Experience in Authentic Research with NASA) where they were GLOBE trained in Atmosphere protocols, and engaged in 1-3 years of research under the mentorship of NASA scientists. Each school was loaned two aerosol instruments for the Campaign duration, either 2 GLOBE sun photometers, 2 Calitoo sun photometers, or 1 of each. This allowed for students to make measurements side-by-side and in the case of the Calitoos, to compare AOT results immediately with each other for better consistency in data collection. Additionally, as part of the Field Campaign evaluation, multiple instruments allow for an assessment of the ease of use of each instrument for grade level of students, whether in middle school or high school. Before the Campaign, all GLOBE and Calitoo instruments were 'checked out' against an AERONET, then checked again upon return after the Campaign. By examining all data, before, during and after the Campaign, this gives an indication of instrument performance and proficiency obtained by the students. Support was provided to each teacher and their students at the level requested, via email, phone or video conferencing.

  3. Clinical study of the visual field defects caused by occipital lobe lesions.

    Science.gov (United States)

    Ogawa, Katsuhiko; Ishikawa, Hiroshi; Suzuki, Yutaka; Oishi, Minoru; Kamei, Satoshi

    2014-01-01

    The central visual field is projected to the region from the occipital tip to the posterior portion of the medial area in the striate cortex. However, central visual field disturbances have not been compared with the location of the lesions in the striate cortex. Thirteen patients with visual field defects caused by partial involvement of the striate cortex were enrolled. The lesions were classified according to their location into the anterior portion, the posterior portion of the medial area, and the occipital tip. Visual field defects were examined by the Goldmann perimetry, the Humphrey perimetry and the auto-plot tangent screen. We defined a defect within the central 10° of vision as a central visual field disturbance. The visual field defects in 13 patients were compared with the location of their lesions in the striate cortex. The medial area was involved in 7 patients with no involvement of the occipital tip. In 2 of them, peripheral homonymous hemianopia without central visual field disturbance was shown, and their lesions were located only in the anterior portion. One patient with a lesion in the posterior portion alone showed incomplete central homonymous hemianopia. Three of 4 patients with lesions located in both the anterior and posterior portions of the medial area showed incomplete central homonymous hemianopia and peripheral homonymous hemianopia. The occipital tip was involved in 6 patients. Five of them had small lesions in the occipital tip alone and showed complete central homonymous hemianopia or quadrantanopia. The other patient with a lesion in the lateral posterior portion and bilateral occipital tip lesions showed bilateral slight peripheral visual field disturbance in addition to complete central homonymous hemianopia on both sides. Lesions in the posterior portion of the medial area as well as the occipital tip caused central visual field disturbance in our study, as indicated in previous reports. Central homonymous hemianopia tended to

  4. Field emission studies at Saclay and Orsay

    International Nuclear Information System (INIS)

    Tan, J.

    1996-01-01

    During the last five years, DC and RF equipment for field emission studies have been developed at Saclay and Orsay laboratories. Combining these devices, straight comparison has been carried out between DC and RF field emission from artificial emission sites on the same sample. Other topics are also reviewed: high field cleaning, plausible origins of thermal effects that occurred on emission sites in RF, behaviour of alumina particles under RF field, and optical observations and measurements. (author)

  5. Reflections on the Field of Educational Management Studies.

    Science.gov (United States)

    Fitz, John

    1999-01-01

    Explores educational management studies as an intellectual field. Draws on Bernstein and Bourieu's theorization of "field" to identify its specialized discourse, field positions and their objective relations, and the location of field occupants (the academic, the practitioner, and the entrepreneur). This configuration shapes educational…

  6. Extraction of the Electric Field in Field Plate Assisted RESURF Devices

    NARCIS (Netherlands)

    Boksteen, B.K.; Dhar, S.; Heringa, A.; Koops, G.E.J.; Hueting, Raymond Josephus Engelbart

    2012-01-01

    It has previously been reported that the lateral electric field (Ex) in the drain extension of thin SOI HV (700V) field plate assisted RESURF devices can be extracted from their ID-VD characteristics in the subthreshold regime. In this work the prerequisites for valid field extraction and the

  7. First-principles study of anharmonic phonon effects in tetrahedral semiconductors via an external electric field

    Energy Technology Data Exchange (ETDEWEB)

    Dabiri, Zohreh, E-mail: z.dabiri@stu.yazd.ac.ir [Physics Department, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of); Kazempour, Ali [Department of Physics, Payame Noor University, P.O. BOX 119395-3697, Tehran (Iran, Islamic Republic of); Nano Structured Coatings Institute of Yazd Payame Noor University, P.O. Code 89431-74559, Yazd (Iran, Islamic Republic of); Sadeghzadeh, Mohammad Ali [Physics Department, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of)

    2016-11-15

    The strength of phonon anharmonicity is investigated in the framework of the Density Functional Perturbation Theory via an applied constant electric field. In contrast to routine approaches, we have employed the electric field as an effective probe to quest after the quasi-harmonic and anharmonic effects. Two typical tetrahedral semiconductors (diamond and silicon) have been selected to test the efficiency of this approach. In this scheme the applied field is responsible for establishing the perturbation and also inducing the anharmonicity in systems. The induced polarization is a result of changing the electronic density while ions are located at their ground state coordinates or at a specified strain. Employing this method, physical quantities of the semiconductors are calculated in presence of the electron–phonon interaction directly and, phonon–phonon interaction, indirectly. The present approach, which is in good agreement with previous theoretical and experimental studies, can be introduced as a benchmark to simply investigate the anharmonicity and pertinent consequences in materials.

  8. Life-history traits in an evergreen Mediterranean oak respond differentially to previous experimental environments

    Directory of Open Access Journals (Sweden)

    J. M. Rey Benayas

    2008-06-01

    Full Text Available Living organisms respond both to current and previous environments, which can have important consequences on population dynamics. However, there is little experimental evidence based on long-term field studies of the effects of previous environments on the performance of individuals. We tested the hypothesis that trees that establish under different environmental conditions perform differently under similar post-establishment conditions. We used the slow-growing, evergreen Mediterranean oak Quercus ilex subsp. rotundifolia as target species. We analyzed the effects of previous environments, competition effects and tradeoffs among life-history traits (survival, growth, and reproduction. We enhanced seedling establishment for three years by reducing abiotic environmental harshness by means of summer irrigation and artificial shading in 12 experimental plots, while four plots remained as controls. Then these treatments were interrupted for ten years. Seedlings under ameliorated environmental conditions survived and grew faster during early establishment. During the post-management period, previous treatments 1 did not have any effect on survival, 2 experienced a slower above-ground growth, 3 decreased root biomass as indicated from reflectivity of Ground Penetration Radar, 4 increased acorn production mostly through a greater canopy volume and 5 increased acorn production effort. The trees exhibited a combination of effects related to acclimation for coping with abiotic stress and effects of intra-specific competition. In accordance with our hypothesis, tree performance overall depended on previous environmental conditions, and the response was different for different life-history traits. We recommend early management because it increased plot cover, shortened the time to attain sexual maturity and increased the amount of acorn production. Plots such as those assessed in this study may act as sources of propagules in deforested

  9. Use of a ring chromosome and pulsed-field gels to study recombinational repair

    International Nuclear Information System (INIS)

    Game, J.C.; Arabi, S.; Mortimer, R.K.

    1989-01-01

    In wild type yeast, it is known that x-ray induced DNA double-strand breaks (dsb) are repaired, leading to recovery of high molecular-weight molecules on gradients or pulsed-field gels. There is genetic evidence that some or all of this repair occurs via recombinational mechanisms involving sister-chromatid exchange (SCE) and (in diploids) inter-homologue recombination. However, this evidence is indirect and qualitative. The authors of this paper are attempting to use pulsed-field gels to detect and measure recombinational repair at the physical level in yeast strains with a circular homologue of Chr. III. The authors have previously used such strains to study meiotic recombination. The authors have shown that double-size circular molecules can be detected in log-phase haploid yeast cells carrying a ring chromosome, when such cells are exposed to x-rays and allowed time for subsequent repair. Large circular molecules will not enter our pulsed-field gels, but treatment of the DNA samples with radiation prior to running the gels will linearize a fraction of such molecules with a single dsb. Such linearized molecules will run as a band whose position indicates the size of the original unbroken circles

  10. Genus-Specific Primers for Study of Fusarium Communities in Field Samples

    Science.gov (United States)

    Edel-Hermann, Véronique; Gautheron, Nadine; Durling, Mikael Brandström; Kolseth, Anna-Karin; Steinberg, Christian; Persson, Paula; Friberg, Hanna

    2015-01-01

    Fusarium is a large and diverse genus of fungi of great agricultural and economic importance, containing many plant pathogens and mycotoxin producers. To date, high-throughput sequencing of Fusarium communities has been limited by the lack of genus-specific primers targeting regions with high discriminatory power at the species level. In the present study, we evaluated two Fusarium-specific primer pairs targeting translation elongation factor 1 (TEF1). We also present the new primer pair Fa+7/Ra+6. Mock Fusarium communities reflecting phylogenetic diversity were used to evaluate the accuracy of the primers in reflecting the relative abundance of the species. TEF1 amplicons were subjected to 454 high-throughput sequencing to characterize Fusarium communities. Field samples from soil and wheat kernels were included to test the method on more-complex material. For kernel samples, a single PCR was sufficient, while for soil samples, nested PCR was necessary. The newly developed primer pairs Fa+7/Ra+6 and Fa/Ra accurately reflected Fusarium species composition in mock DNA communities. In field samples, 47 Fusarium operational taxonomic units were identified, with the highest Fusarium diversity in soil. The Fusarium community in soil was dominated by members of the Fusarium incarnatum-Fusarium equiseti species complex, contradicting findings in previous studies. The method was successfully applied to analyze Fusarium communities in soil and plant material and can facilitate further studies of Fusarium ecology. PMID:26519387

  11. Implant breast reconstruction after salvage mastectomy in previously irradiated patients.

    Science.gov (United States)

    Persichetti, Paolo; Cagli, Barbara; Simone, Pierfranco; Cogliandro, Annalisa; Fortunato, Lucio; Altomare, Vittorio; Trodella, Lucio

    2009-04-01

    The most common surgical approach in case of local tumor recurrence after quadrantectomy and radiotherapy is salvage mastectomy. Breast reconstruction is the subsequent phase of the treatment and the plastic surgeon has to operate on previously irradiated and manipulated tissues. The medical literature highlights that breast reconstruction with tissue expanders is not a pursuable option, considering previous radiotherapy a contraindication. The purpose of this retrospective study is to evaluate the influence of previous radiotherapy on 2-stage breast reconstruction (tissue expander/implant). Only patients with analogous timing of radiation therapy and the same demolitive and reconstructive procedures were recruited. The results of this study prove that, after salvage mastectomy in previously irradiated patients, implant reconstruction is still possible. Further comparative studies are, of course, advisable to draw any conclusion on the possibility to perform implant reconstruction in previously irradiated patients.

  12. Study of interacting fields in a canonical formalism in Heisenberg picture of quantum field theory

    International Nuclear Information System (INIS)

    RANAIVOSON, R.T.R.

    2011-01-01

    In this work, we have made a study on the canonical formalism of the quantum field theory. Our contribution has been the development of a study using the Heisenberg picture. We showed that this approach may be useful for the description of quantum dynamics of interacting fields in bounded states. Our approach is to start from the lagrangian density of a classical theory from which one deduce the classical evolution equations of the fields via Euler-Lagrange equation for fields and establish the expression of conserved quantities characterizing the dynamics using the Noether theorem. Passing to the canonical quantization, fields and quantities characterizing the dynamics become quantum operators and evolution equations become operatorial evolution equations in Heisenberg picture. Expressions of quantum observable are also deduced from the expressions of classical conserved quantities. After, we showed that using the properties of fields operators and quantum states vectors, one can deduce from the operatorial evolution equations, the evolution equations for the wave functions of fermions and the evolution equations of expectation values of boson fields. For the illustration, various studies were conducted: the case of electrodynamics, the case of a general gauge theory and the case of the Standard Model. [fr

  13. Field desorption and field ion surface studies of samples exposed to the plasmas of PLT and ISX

    International Nuclear Information System (INIS)

    Kellogg, G.L.; Panitz, J.A.

    1978-01-01

    Modifications to the surface of field-ion specimens exposed to plasma discharges in PLT and ISX determined by Imaging Probe, Field Ion Microscope, and Transmission Electron Microscope analysis have in the past shown several consistent features. Surface films consisting primarily of limiter material with trapped plasma and impurity species have been found to reside on samples with direct line of sight exposure to the plasma during the discharges. Control specimens placed in the tokamak, but shielded from the plasma, on the other hand, remained free of deposits. When exposed to only high power plasma discharges, samples placed at the wall position in PLT and ISX have survived the exposures with no evidence of damage or implantation. In this paper we describe the results of a recent exposure in PLT in which for the first time samples of stainless steel were included for High-Field Surface Analysis. Tokamak operating conditions, including stainless-steel limiters, titanium gettering between discharges, and the occurrence of a disruption, also distinguished this exposure from those carried out previously. Surprisingly, even with stainless-steel limiters, carbon films were found to be deposited on the samples at a rate

  14. A Study of QMM Hysteresis Cycle Data. Field Linearity and Field Reproducibility

    International Nuclear Information System (INIS)

    Vernin, P.; Fonvieille, H.; Quemener, G.

    1997-08-01

    A study of the hysteresis data provided by the quadrupole field mapping of the HRS Electron Arm is presented. For each quad Q1, Q2, Q3, a series of runs was performed to obtain the hysteresis curve of the magnet at maximal current. The focus of the present document is not the field maps but a specific analysis of QMM data in terms of hysteresis curves, and field linearity as a function of the current. These measurements allow to put limits on the reproducibility of magnet setting for the presently used operating mode of the quads. (K.A.)

  15. Interaction of magnetic resonators studied by the magnetic field enhancement

    Directory of Open Access Journals (Sweden)

    Yumin Hou

    2013-12-01

    Full Text Available It is the first time that the magnetic field enhancement (MFE is used to study the interaction of magnetic resonators (MRs, which is more sensitive than previous parameters–shift and damping of resonance frequency. To avoid the coherence of lattice and the effect of Bloch wave, the interaction is simulated between two MRs with same primary phase when the distance is changed in the range of several resonance wavelengths, which is also compared with periodic structure. The calculated MFE oscillating and decaying with distance with the period equal to resonance wavelength directly shows the retardation effect. Simulation also shows that the interaction at normal incidence is sensitive to the phase correlation which is related with retardation effect and is ultra-long-distance interaction when the two MRs are strongly localized. When the distance is very short, the amplitude of magnetic resonance is oppressed by the strong interaction and thus the MFE can be much lower than that of single MR. This study provides the design rules of metamaterials for engineering resonant properties of MRs.

  16. Acceleration and Orientation Jumping Performance Differences Among Elite Professional Male Handball Players With or Without Previous ACL Reconstruction: An Inertial Sensor Unit-Based Study.

    Science.gov (United States)

    Setuain, Igor; González-Izal, Miriam; Alfaro, Jesús; Gorostiaga, Esteban; Izquierdo, Mikel

    2015-12-01

    Handball is one of the most challenging sports for the knee joint. Persistent biomechanical and jumping capacity alterations can be observed in athletes with an anterior cruciate ligament (ACL) injury. Commonly identified jumping biomechanical alterations have been described by the use of laboratory technologies. However, portable and easy-to-handle technologies that enable an evaluation of jumping biomechanics at the training field are lacking. To analyze unilateral/bilateral acceleration and orientation jumping performance differences among elite male handball athletes with or without previous ACL reconstruction via a single inertial sensor unit device. Case control descriptive study. At the athletes' usual training court. Twenty-two elite male (6 ACL-reconstructed and 16 uninjured control players) handball players were evaluated. The participants performed a vertical jump test battery that included a 50-cm vertical bilateral drop jump, a 20-cm vertical unilateral drop jump, and vertical unilateral countermovement jump maneuvers. Peak 3-dimensional (X, Y, Z) acceleration (m·s(-2)), jump phase duration and 3-dimensional orientation values (°) were obtained from the inertial sensor unit device. Two-tailed t-tests and a one-way analysis of variance were performed to compare means. The P value cut-off for significance was set at P handball athletes with previous ACL reconstruction demonstrated a jumping biomechanical profile similar to control players, including similar jumping performance values in both bilateral and unilateral jumping maneuvers, several years after ACL reconstruction. These findings are in agreement with previous research showing full functional restoration of abilities in top-level male athletes after ACL reconstruction, rehabilitation and subsequent return to sports at the previous level. Copyright © 2015 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  17. Physical transformations of iron oxide and silver nanoparticles from an intermediate scale field transport study

    Science.gov (United States)

    Emerson, Hilary P.; Hart, Ashley E.; Baldwin, Jonathon A.; Waterhouse, Tyler C.; Kitchens, Christopher L.; Mefford, O. Thompson; Powell, Brian A.

    2014-02-01

    In recent years, there has been increasing concern regarding the fate and transport of engineered nanoparticles (NPs) in environmental systems and the potential impacts on human and environmental health due to the exponential increase in commercial and industrial use worldwide. To date, there have been relatively few field-scale studies or laboratory-based studies on environmentally relevant soils examining the chemical/physical behavior of the NPs following release into natural systems. The objective of this research is to demonstrate the behavior and transformations of iron oxide and silver NPs with different capping ligands within the unsaturated zone. Here, we show that NP transport within the vadose zone is minimal primarily due to heteroaggregation with soil surface coatings with results that >99 % of the NPs remained within 5 cm of the original source after 1 year in intermediate-scale field lysimeters. These results suggest that transport may be overestimated when compared to previous laboratory-scale studies on pristine soils and pure minerals and that future work must incorporate more environmentally relevant parameters.

  18. Can dark matter be a scalar field?

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, J.F.; Malatrasi, J.L.G. [Universidade Estadual Paulista ' Júlio de Mesquita Filho' , Campus Experimental de Itapeva—R. Geraldo Alckmin, 519, Itapeva, SP (Brazil); Pereira, S.H. [Universidade Estadual Paulista ' Júlio de Mesquita Filho' , Departamento de Física e Química, Campus de Guaratinguetá, Av. Dr. Ariberto Pereira da Cunha, 333, 12516-410—Guaratinguetá, SP (Brazil); Andrade-Oliveira, F., E-mail: jfjesus@itapeva.unesp.br, E-mail: shpereira@gmail.com, E-mail: malatrasi440@gmail.com, E-mail: felipe.oliveira@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Burnaby Road, PO1 3FX, Portsmouth (United Kingdom)

    2016-08-01

    In this paper we study a real scalar field as a possible candidate to explain the dark matter in the universe. In the context of a free scalar field with quadratic potential, we have used Union 2.1 SN Ia observational data jointly with a Planck prior over the dark matter density parameter to set a lower limit on the dark matter mass as m ≥0.12 H {sub 0}{sup -1} eV ( c = h-bar =1). For the recent value of the Hubble constant indicated by the Hubble Space Telescope, namely H {sub 0}=73±1.8 km s{sup -1}Mpc{sup -1}, this leads to m ≥1.56×10{sup -33} eV at 99.7% c.l. Such value is much smaller than m ∼ 10{sup -22} eV previously estimated for some models. Nevertheless, it is still in agreement with them once we have not found evidences for a upper limit on the scalar field dark matter mass from SN Ia analysis. In practice, it confirms free real scalar field as a viable candidate for dark matter in agreement with previous studies in the context of density perturbations, which include scalar field self interaction.

  19. Dual double field theory

    Energy Technology Data Exchange (ETDEWEB)

    Bergshoeff, Eric A. [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Hohm, Olaf [Simons Center for Geometry and Physics, Stony Brook University,Stony Brook, NY 11794-3636 (United States); Penas, Victor A. [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Riccioni, Fabio [INFN - Sezione di Roma, Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy)

    2016-06-06

    We present the dual formulation of double field theory at the linearized level. This is a classically equivalent theory describing the duals of the dilaton, the Kalb-Ramond field and the graviton in a T-duality or O(D,D) covariant way. In agreement with previous proposals, the resulting theory encodes fields in mixed Young-tableau representations, combining them into an antisymmetric 4-tensor under O(D,D). In contrast to previous proposals, the theory also requires an antisymmetric 2-tensor and a singlet, which are not all pure gauge. The need for these additional fields is analogous to a similar phenomenon for “exotic' dualizations, and we clarify this by comparing with the dualizations of the component fields. We close with some speculative remarks on the significance of these observations for the full non-linear theory yet to be constructed.

  20. Case-control study for colorectal cancer genetic susceptibility in EPICOLON: previously identified variants and mucins

    Directory of Open Access Journals (Sweden)

    Moreno Victor

    2011-08-01

    Full Text Available Abstract Background Colorectal cancer (CRC is the second leading cause of cancer death in developed countries. Familial aggregation in CRC is also important outside syndromic forms and, in this case, a polygenic model with several common low-penetrance alleles contributing to CRC genetic predisposition could be hypothesized. Mucins and GALNTs (N-acetylgalactosaminyltransferase are interesting candidates for CRC genetic susceptibility and have not been previously evaluated. We present results for ten genetic variants linked to CRC risk in previous studies (previously identified category and 18 selected variants from the mucin gene family in a case-control association study from the Spanish EPICOLON consortium. Methods CRC cases and matched controls were from EPICOLON, a prospective, multicenter, nationwide Spanish initiative, comprised of two independent stages. Stage 1 corresponded to 515 CRC cases and 515 controls, whereas stage 2 consisted of 901 CRC cases and 909 controls. Also, an independent cohort of 549 CRC cases and 599 controls outside EPICOLON was available for additional replication. Genotyping was performed for ten previously identified SNPs in ADH1C, APC, CCDN1, IL6, IL8, IRS1, MTHFR, PPARG, VDR and ARL11, and 18 selected variants in the mucin gene family. Results None of the 28 SNPs analyzed in our study was found to be associated with CRC risk. Although four SNPs were significant with a P-value ADH1C (OR = 1.63, 95% CI = 1.06-2.50, P-value = 0.02, recessive, rs1800795 in IL6 (OR = 1.62, 95% CI = 1.10-2.37, P-value = 0.01, recessive, rs3803185 in ARL11 (OR = 1.58, 95% CI = 1.17-2.15, P-value = 0.007, codominant, and rs2102302 in GALNTL2 (OR = 1.20, 95% CI = 1.00-1.44, P-value = 0.04, log-additive 0, 1, 2 alleles], only rs3803185 achieved statistical significance in EPICOLON stage 2 (OR = 1.34, 95% CI = 1.06-1.69, P-value = 0.01, recessive. In the joint analysis for both stages, results were only significant for rs3803185 (OR = 1

  1. Case-control study for colorectal cancer genetic susceptibility in EPICOLON: previously identified variants and mucins

    International Nuclear Information System (INIS)

    Abulí, Anna; Morillas, Juan D; Rigau, Joaquim; Latorre, Mercedes; Fernández-Bañares, Fernando; Peña, Elena; Riestra, Sabino; Payá, Artemio; Jover, Rodrigo; Xicola, Rosa M; Llor, Xavier; Fernández-Rozadilla, Ceres; Carvajal-Carmona, Luis; Villanueva, Cristina M; Moreno, Victor; Piqué, Josep M; Carracedo, Angel; Castells, Antoni; Andreu, Montserrat; Ruiz-Ponte, Clara; Castellví-Bel, Sergi; Alonso-Espinaco, Virginia; Muñoz, Jenifer; Gonzalo, Victoria; Bessa, Xavier; González, Dolors; Clofent, Joan; Cubiella, Joaquin

    2011-01-01

    Colorectal cancer (CRC) is the second leading cause of cancer death in developed countries. Familial aggregation in CRC is also important outside syndromic forms and, in this case, a polygenic model with several common low-penetrance alleles contributing to CRC genetic predisposition could be hypothesized. Mucins and GALNTs (N-acetylgalactosaminyltransferase) are interesting candidates for CRC genetic susceptibility and have not been previously evaluated. We present results for ten genetic variants linked to CRC risk in previous studies (previously identified category) and 18 selected variants from the mucin gene family in a case-control association study from the Spanish EPICOLON consortium. CRC cases and matched controls were from EPICOLON, a prospective, multicenter, nationwide Spanish initiative, comprised of two independent stages. Stage 1 corresponded to 515 CRC cases and 515 controls, whereas stage 2 consisted of 901 CRC cases and 909 controls. Also, an independent cohort of 549 CRC cases and 599 controls outside EPICOLON was available for additional replication. Genotyping was performed for ten previously identified SNPs in ADH1C, APC, CCDN1, IL6, IL8, IRS1, MTHFR, PPARG, VDR and ARL11, and 18 selected variants in the mucin gene family. None of the 28 SNPs analyzed in our study was found to be associated with CRC risk. Although four SNPs were significant with a P-value < 0.05 in EPICOLON stage 1 [rs698 in ADH1C (OR = 1.63, 95% CI = 1.06-2.50, P-value = 0.02, recessive), rs1800795 in IL6 (OR = 1.62, 95% CI = 1.10-2.37, P-value = 0.01, recessive), rs3803185 in ARL11 (OR = 1.58, 95% CI = 1.17-2.15, P-value = 0.007, codominant), and rs2102302 in GALNTL2 (OR = 1.20, 95% CI = 1.00-1.44, P-value = 0.04, log-additive 0, 1, 2 alleles], only rs3803185 achieved statistical significance in EPICOLON stage 2 (OR = 1.34, 95% CI = 1.06-1.69, P-value = 0.01, recessive). In the joint analysis for both stages, results were only significant for rs3803185 (OR = 1.12, 95% CI = 1

  2. Do attitudes of families concerned influence features of children who claim to remember previous lives?

    Science.gov (United States)

    Pasricha, Satwant K

    2011-01-01

    Reported cases of nearly 2600 children (subjects) who claim to remember previous lives have been investigated in cultures with and without belief in reincarnation. The authenticity in most cases has been established. To study the influence of attitudes of parents of the subjects, families of the deceased person with whom they are identified and attention paid by others on the features of the cases. The study is based on field investigations. Data is derived from analysis of a larger series of an ongoing project. Information on initial and subsequent attitudes of subjects' mothers was available for 292 and 136 cases, respectively; attitudes of 227 families of deceased person (previous personality) with whom he is identified, and the extent of attention received from outsiders for 252 cases. Observations and interviews with multiple firsthand informants on both sides of the case as well as some neutral informants supplemented by examination of objective data were the chief methods of investigation. The initial attitude of mothers varied from encouragement (21%) to neutral or tolerance (51%) to discouragement (28%). However, it changed significantly from neutrality to taking measures to induce amnesia in their children for previous life memories due to various psychosocial pressures and prevalent beliefs. Families of the previous personalities, once convinced, showed complete acceptance in a majority of cases. Outside attention was received in 58% cases. The positive attitude of parents might facilitate expression of memories but subsequently attitudes of persons concerned do not seem to alter features of the cases.

  3. Entanglement entropy in scalar field theory on the fuzzy sphere

    International Nuclear Information System (INIS)

    Okuno, Shizuka; Suzuki, Mariko; Tsuchiya, Asato

    2016-01-01

    We study entanglement entropy on the fuzzy sphere. We calculate it in a scalar field theory on the fuzzy sphere, which is given by a matrix model. We use a method that is based on the replica method and applicable to interacting fields as well as free fields. For free fields, we obtain results consistent with the previous study, which serves as a test of the validity of the method. For interacting fields, we perform Monte Carlo simulations at strong coupling and see a novel behavior of entanglement entropy

  4. Properties and cleanability of new and traditional surface materials in cattle barns - a field study

    Directory of Open Access Journals (Sweden)

    R. KUISMA

    2008-12-01

    Full Text Available In this study surface properties and cleanability of new and traditional surface materials in cattle barns were examined in a field test. The concrete and plastic-coated samples were placed on a walking path on the floor and on a feeding table in a cattle barn. The surfaces were characterized using colorimetric and gloss measurements and determination of topography. In most cases, the colour of the surfaces placed on the floor darkened during the one year study period, whereas the colour changes of the samples placed on the feeding table did not show a similar trend. However, in both locations the plastic-coated surfaces were generally the easiest to clean, and the highest colour changes indicating soil residues were detected on the uncoated and silane-impregnated concrete surfaces. The difference between the locations was also seen in the gloss values, which increased in the samples placed on the floor during the one-year test period but varied considerably between the different materials on the surfaces placed on the feeding table. This field study confirmed the observation from earlier laboratory studies that plastic coatings improved the cleanability of concrete cattle barn surfaces. Silane impregnation was not functionally competitive with the plastic coatings. In general, the cleanability results were in accordance with the results of previous laboratory experiments but the field study provided practical information about the behaviour of the surface materials examined.;

  5. Microwave magnetoelectric fields: An analytical study of topological characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Joffe, R., E-mail: ioffr1@gmail.com [Microwave Magnetic Laboratory, Department of Electrical and Computer Engineering, Ben Gurion University of the Negev, Beer Sheva (Israel); Department of Electrical and Electronics Engineering, Shamoon College of Engineering, Beer Sheva (Israel); Shavit, R.; Kamenetskii, E.O. [Microwave Magnetic Laboratory, Department of Electrical and Computer Engineering, Ben Gurion University of the Negev, Beer Sheva (Israel)

    2015-10-15

    The near fields originated from a small quasi-two-dimensional ferrite disk with magnetic-dipolar-mode (MDM) oscillations are the fields with broken dual (electric-magnetic) symmetry. Numerical studies show that such fields – called the magnetoelectric (ME) fields – are distinguished by the power-flow vortices and helicity parameters (E.O. Kamenetskii, R. Joffe, R. Shavit, Phys. Rev. E 87 (2013) 023201). These numerical studies can well explain recent experimental results with MDM ferrite disks. In the present paper, we obtain analytically topological characteristics of the ME-field modes. For this purpose, we used a method of successive approximations. In the second approximation we take into account the influence of the edge regions of an open ferrite disk, which are excluded in the first-approximation solving of the magnetostatic (MS) spectral problem. Based on the analytical method, we obtain a “pure” structure of the electric and magnetic fields outside the MDM ferrite disk. The analytical studies can display some fundamental features that are non-observable in the numerical results. While in numerical investigations, one cannot separate the ME fields from the external electromagnetic (EM) radiation, the present theoretical analysis allows clearly distinguish the eigen topological structure of the ME fields. Importantly, this ME-field structure gives evidence for certain phenomena that can be related to the Tellegen and bianisotropic coupling effects. We discuss the question whether the MDM ferrite disk can exhibit properties of the cross magnetoelectric polarizabilities. - Highlights: • We obtain analytically topological characteristics of the ME-field modes. • We take into account the influence of the edge regions of an open ferrite disk. • We obtain a “pure” structure of the electromagnetic fields outside the ferrite disk. • Analytical studies show features that are non-observable in the numerical results. • ME-field gives evidence for

  6. Microwave magnetoelectric fields: An analytical study of topological characteristics

    International Nuclear Information System (INIS)

    Joffe, R.; Shavit, R.; Kamenetskii, E.O.

    2015-01-01

    The near fields originated from a small quasi-two-dimensional ferrite disk with magnetic-dipolar-mode (MDM) oscillations are the fields with broken dual (electric-magnetic) symmetry. Numerical studies show that such fields – called the magnetoelectric (ME) fields – are distinguished by the power-flow vortices and helicity parameters (E.O. Kamenetskii, R. Joffe, R. Shavit, Phys. Rev. E 87 (2013) 023201). These numerical studies can well explain recent experimental results with MDM ferrite disks. In the present paper, we obtain analytically topological characteristics of the ME-field modes. For this purpose, we used a method of successive approximations. In the second approximation we take into account the influence of the edge regions of an open ferrite disk, which are excluded in the first-approximation solving of the magnetostatic (MS) spectral problem. Based on the analytical method, we obtain a “pure” structure of the electric and magnetic fields outside the MDM ferrite disk. The analytical studies can display some fundamental features that are non-observable in the numerical results. While in numerical investigations, one cannot separate the ME fields from the external electromagnetic (EM) radiation, the present theoretical analysis allows clearly distinguish the eigen topological structure of the ME fields. Importantly, this ME-field structure gives evidence for certain phenomena that can be related to the Tellegen and bianisotropic coupling effects. We discuss the question whether the MDM ferrite disk can exhibit properties of the cross magnetoelectric polarizabilities. - Highlights: • We obtain analytically topological characteristics of the ME-field modes. • We take into account the influence of the edge regions of an open ferrite disk. • We obtain a “pure” structure of the electromagnetic fields outside the ferrite disk. • Analytical studies show features that are non-observable in the numerical results. • ME-field gives evidence for

  7. Technique for sparing previously irradiated critical normal structures in salvage proton craniospinal irradiation

    International Nuclear Information System (INIS)

    McDonald, Mark W; Wolanski, Mark R; Simmons, Joseph W; Buchsbaum, Jeffrey C

    2013-01-01

    Cranial reirradiation is clinically appropriate in some cases but cumulative radiation dose to critical normal structures remains a practical concern. The authors developed a simple technique in 3D conformal proton craniospinal irradiation (CSI) to block organs at risk (OAR) while minimizing underdosing of adjacent target brain tissue. Two clinical cases illustrate the use of proton therapy to provide salvage CSI when a previously irradiated OAR required sparing from additional radiation dose. The prior radiation plan was coregistered to the treatment planning CT to create a planning organ at risk volume (PRV) around the OAR. Right and left lateral cranial whole brain proton apertures were created with a small block over the PRV. Then right and left lateral “inverse apertures” were generated, creating an aperture opening in the shape of the area previously blocked and blocking the area previously open. The inverse aperture opening was made one millimeter smaller than the original block to minimize the risk of dose overlap. The inverse apertures were used to irradiate the target volume lateral to the PRV, selecting a proton beam range to abut the 50% isodose line against either lateral edge of the PRV. Together, the 4 cranial proton fields created a region of complete dose avoidance around the OAR. Comparative photon treatment plans were generated with opposed lateral X-ray fields with custom blocks and coplanar intensity modulated radiation therapy optimized to avoid the PRV. Cumulative dose volume histograms were evaluated. Treatment plans were developed and successfully implemented to provide sparing of previously irradiated critical normal structures while treating target brain lateral to these structures. The absence of dose overlapping during irradiation through the inverse apertures was confirmed by film. Compared to the lateral X-ray and IMRT treatment plans, the proton CSI technique improved coverage of target brain tissue while providing the least

  8. Study of one dimensional magnetic system via field theory

    International Nuclear Information System (INIS)

    Talim, S.L.

    1988-04-01

    We present a study of one-dimensional magnetic system using field theory methods. We studied the discreteness effects in a classical anisotropic one dimensional antiferromagnet in an external magnetic field. It is shown that for TMMC, at the temperatures and magnetic fields where most experiments have been done, the corrections are small and can be neglected. (author)

  9. Policy Forum: Studying Eyewitness Investigations in the Field

    Science.gov (United States)

    Dawes, Robyn; Jacoby, Larry L.; Kahneman, Daniel; Lempert, Richard; Roediger, Henry L.; Rosenthal, Robert

    2007-01-01

    This article considers methodological issues arising from recent efforts to provide field tests of eyewitness identification procedures. We focus in particular on a field study (Mecklenburg 2006) that examined the “double blind, sequential” technique, and consider the implications of an acknowledged methodological confound in the study. We explain why the confound has severe consequences for assessing the real-world implications of this study. PMID:17610149

  10. Field and laboratory evaluations of soybean lines against soybean aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Hesler, Louis S; Prischmann, Deirdre A; Dashiell, Kenton E

    2012-04-01

    The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a major pest of soybean, Glycine max (L.). Merr., that significantly reduces yield in northern production areas of North America. Insecticides are widely used to control soybean aphid outbreaks, but efforts are underway to develop host plant resistance as an effective alternative management strategy. Here, previously identified resistant lines were evaluated in laboratory tests against field-collected populations of soybean aphid and in field-plot tests over 2 yr in South Dakota. Six lines previously identified with resistance to soybean aphid--Jackson, Dowling, K1639, Cobb, Palmetto and Sennari--were resistant in this study, but relatively high aphid counts on Tie-feng 8 in field plots contrasted with its previously reported resistance. Bhart-PI 165989 showed resistance in one of two laboratory tests, but it had relatively large aphid infestations in both years of field tests. Intermediate levels of soybean aphid occurred in field plots on lines previously shown to have strong (Sugao Zairai, PI 230977, and D75-10169) or moderate resistance to soybean aphid (G93-9223, Bragg, Braxton, and Tracy-M). Sugao Zairai also failed to have a significant proportion of resistant plants in two laboratory tests against aphids field-collected in 2008, but it was resistant in laboratory tests with aphids collected in 2002, 2005, and 2006. Overall, results showed that lines with Rag (i.e., Jackson) or Rag1 gene (i.e., Dowling) had low aphid numbers, whereas lines with Rag2 (i.e., Sugao Zairai, Sennari) had mixed results. Collectively, responses of soybean aphid populations in laboratory and field tests in 2008 resembled a virulence pattern reported previously for biotype 3 soybean aphids, but virulence in soybean aphid populations was variable and dynamic over years of the study. These results, coupled with previous reports of biotypes virulent to Rag1, suggest that deployment of lines with a single aphid

  11. Renormalization group study of scalar field theories

    International Nuclear Information System (INIS)

    Hasenfratz, A.; Hasenfratz, P.

    1986-01-01

    An approximate RG equation is derived and studied in scalar quantum field theories in d dimensions. The approximation allows for an infinite number of different couplings in the potential, but excludes interactions containing derivatives. The resulting non-linear partial differential equation can be studied by simple means. Both the gaussian and the non-gaussian fixed points are described qualitatively correctly by the equation. The RG flows in d=4 and the problem of defining an ''effective'' field theory are discussed in detail. (orig.)

  12. Numerical Study of Electric Field Enhanced Combustion

    KAUST Repository

    Han, Jie

    2016-12-26

    Electric fields can be used to change and control flame properties, for example changing flame speed, enhancing flame stability, or reducing pollutant emission. The ions generated in flames are believed to play the primary role. Although experiments have been carried out to study electric field enhanced combustion, they are not sufficient to explain how the ions in a flame are affected by an electric field. It is therefore necessary to investigate the problem through numerical simulations. In the present work, the electric structure of stabilized CH4/air premixed flames at atmospheric pressure within a direct current field is studied using numerical simulations. This study consists of three parts. First, the transport equations are derived from the Boltzmann kinetic equation for each individual species. Second, a general method for computing the diffusivity and mobility of ions in a gas mixture is introduced. Third, the mechanisms for neutral and charged species are improved to give better predictions of the concentrations of charged species, based on experimental data. Following from this, comprehensive numerical results are presented, including the concentrations and fluxes of charged species, the distributions of the electric field and electric potential, and the electric current-voltage relation. Two new concepts introduced with the numerical results are the plasma sheath and dead zone in the premixed flame. A reactive plasma sheath and a Boltzmann relation sheath are discovered in the region near the electrodes. The plasma sheath penetrates into the flame gas when a voltage is applied, and penetrating further if the voltage is higher. The zone outside the region of sheath penetration is defined as the dead zone. With the two concepts, analytical solutions for the electric field, electric potential and current-voltage curve are derived. The solutions directly describe the electric structure of a premixed flame subject to a DC field. These analytical solutions

  13. The integrated analyses of digital field mapping techniques and traditional field methods: implications from the Burdur-Fethiye Shear Zone, SW Turkey as a case-study

    Science.gov (United States)

    Elitez, İrem; Yaltırak, Cenk; Zabcı, Cengiz; Şahin, Murat

    2015-04-01

    The precise geological mapping is one of the most important issues in geological studies. Documenting the spatial distribution of geological bodies and their contacts play a crucial role on interpreting the tectonic evolution of any region. Although the traditional field techniques are still accepted to be the most fundamental tools in construction of geological maps, we suggest that the integration of digital technologies to the classical methods significantly increases the resolution and the quality of such products. We simply follow the following steps in integration of the digital data with the traditional field observations. First, we create the digital elevation model (DEM) of the region of interest by interpolating the digital contours of 1:25000 scale topographic maps to 10 m of ground pixel resolution. The non-commercial Google Earth satellite imagery and geological maps of previous studies are draped over the interpolated DEMs in the second stage. The integration of all spatial data is done by using the market leading GIS software, ESRI ArcGIS. We make the preliminary interpretation of major structures as tectonic lineaments and stratigraphic contacts. These preliminary maps are controlled and precisely coordinated during the field studies by using mobile tablets and/or phablets with GPS receivers. The same devices are also used in measuring and recording the geologic structures of the study region. Finally, all digitally collected measurements and observations are added to the GIS database and we finalise our geological map with all available information. We applied this integrated method to map the Burdur-Fethiye Shear Zone (BFSZ) in the southwest Turkey. The BFSZ is an active sinistral 60-to-90 km-wide shear zone, which prolongs about 300 km-long between Suhut-Cay in the northeast and Köyceğiz Lake-Kalkan in the southwest on land. The numerous studies suggest contradictory models not only about the evolution but also about the fault geometry of this

  14. Communication linguistique: Etude comparative faite sur le terrain (Linguistic Communication: A Comparative Field Study).

    Science.gov (United States)

    Piron, Claude

    2002-01-01

    Compares the four international systems of linguistic communication used in the field (systems used in the United Nations, multinationals, the European Union, and Esperanto organizations) on select criteria (e.g., previous government investment). Discusses research that shows unilingual systems (English used alone, Esperanto) are those that…

  15. Gravity Field Constraints on the Upper Mantle of Northwestern Europe

    NARCIS (Netherlands)

    Root, B.C.

    2017-01-01

    In the last decade, the gravity field of the Earth has been observed with increased coverage due to dedicated satellite missions, which resulted in higher resolution and more accurate global gravity field models than were previously available. These models make it possible to study large scale

  16. Gendered Choices : Fields of study of adolescents in the Netherlands

    OpenAIRE

    van der Vleuten, M.

    2018-01-01

    Choosing a field of study is an important decision in determining future educational trajectories and occupations, and we know that boys and girls make different field of study choices. Girls are underrepresented in gender-stereotypical masculine fields like science and technology, whereas boys are underrepresented in gender-stereotypical feminine fields like education or health-related fields. This dissertation provides insight in the different ways in which adolescents’ social environment a...

  17. Polychlorinated biphenyl exposure, diabetes and endogenous hormones: a cross-sectional study in men previously employed at a capacitor manufacturing plant.

    Science.gov (United States)

    Persky, Victoria; Piorkowski, Julie; Turyk, Mary; Freels, Sally; Chatterton, Robert; Dimos, John; Bradlow, H Leon; Chary, Lin Kaatz; Burse, Virlyn; Unterman, Terry; Sepkovic, Daniel W; McCann, Kenneth

    2012-08-29

    Studies have shown associations of diabetes and endogenous hormones with exposure to a wide variety of organochlorines. We have previously reported positive associations of polychlorinated biphenyls (PCBs) and inverse associations of selected steroid hormones with diabetes in postmenopausal women previously employed in a capacitor manufacturing plant. This paper examines associations of PCBs with diabetes and endogenous hormones in 63 men previously employed at the same plant who in 1996 underwent surveys of their exposure and medical history and collection of bloods and urine for measurements of PCBs, lipids, liver function, hematologic markers and endogenous hormones. PCB exposure was positively associated with diabetes and age and inversely associated with thyroid stimulating hormone and triiodothyronine-uptake. History of diabetes was significantly related to total PCBs and all PCB functional groupings, but not to quarters worked and job score, after control for potential confounders. None of the exposures were related to insulin resistance (HOMA-IR) in non-diabetic men. Associations of PCBs with specific endogenous hormones differ in some respects from previous findings in postmenopausal women employed at the capacitor plant. Results from this study, however, do confirm previous reports relating PCB exposure to diabetes and suggest that these associations are not mediated by measured endogenous hormones.

  18. Studies on the effect of radio frequency field in a cusp-type charge separation device for direct energy conversion

    International Nuclear Information System (INIS)

    Hamabe, Masaki; Izawa, Hiroaki; Takeno, Hiromasa; Nakamoto, Satoshi; Ichimura, Kazuya; Nakashima, Yousuke

    2016-01-01

    In D- 3 He fusion power generation, an application of direct energy conversion is expected in which separation of charged particles is necessary. A cusp-type direct energy converter (CuspDEC) was proposed as a charge separation device, but its performance was degraded for a high density plasma. The goal of the present study is to establish an additional method to assist charge separation by using a nonlinear effect of a radio frequency (rf) electric field. Following to the previous study, we experimentally examine the effect of an rf field to electron motion in a CuspDEC device. Two ring electrodes were newly installed in a CuspDEC simulator and the current flowing into the electron collector located in the line cusp region was measured on an rf field application. The significant variation in the current was found, and an improvement of the charge separation can be expected by using the phenomenon appropriately. (author)

  19. Studies on the Effect of Radio Frequency Field in a Cusp-Type Charge Separation Device for Direct Energy Conversion

    OpenAIRE

    HAMABE, Masaki; IZAWA, Hiroaki; TAKENO, Hiromasa; NAKAMOTO, Satoshi; ICHIMURA, Kazuya; NAKASHIMA, Yousuke

    2016-01-01

    In D-3He fusion power generation, an application of direct energy conversion is expected in which separation of charged particles is necessary. A cusp-type direct energy converter (CuspDEC) was proposed as a charge separation device, but its performance was degraded for a high density plasma. The goal of the present study is to establish an additional method to assist charge separation by using a nonlinear effect of a radio frequency (rf) electric field. Following to the previous study, we ex...

  20. Reversed field pinch reactor study 3

    International Nuclear Information System (INIS)

    Hollis, A.A.; Mitchell, J.T.D.

    1977-12-01

    This report, the third of a series on the Reversed Field Pinch Reactor, describes a preliminary concept of the engineering design and layout of this pulsed toroidal reactor, which uses the stable plasma behaviour first observed in ZETA. The basic parameters of the 600 MW(e) reactor are taken from a companion study by Hancox and Spears. The plasma volume is 1.75m minor radius and 16m major radius surrounded by a 1.8m blanket-shield region - with the blanket divided into 14 removable segments for servicing. The magnetic confinement system consists of 28 toroidal field coils situated just outside the blanket and inside the poloidal and vertical field coils and all coils have normal copper conductors. The requirement to incorporate a conducting shell at the front of the blanket to provide a short-time plasma stability has a marked effect on the design. It sets the size of the blanket segment and the scale of the servicing operations, limits the breeding gain and complicates the blanket cooling and its integration with the heat engine. An extensive study will be required to confirm the overall reactor potential of the concept. (author)

  1. High-field magnetization studies of U2T2Sn (T=Co, Ir, Pt) compounds

    International Nuclear Information System (INIS)

    Prokes, K.; Nakotte, H.; de Boer, F.R.

    1995-01-01

    High-field magnetization measurements at 4.2 K on U 2 T 2 Sn (T = Co, Ir and Pt) compounds have been performed on free and fixed powders up to 57 T. An antiferromagnetic ground state of U 2 Pt 2 Sn is corroborated by a metamagnetic transition at 22 T with very small hysteresis going up and down with field. U 2 Co 2 Sn and U 2 Ir 2 Sn show no metamagnetic transition up to 57 T which is in agreement with the non-magnetic ground state of these compounds. In all cases, the maximum applied field is not sufficient to achieve saturation. The short-pulse measurements presented here are compared with previous results obtained in quasi-static fields up to 35 T

  2. NATO Advanced Study Institute on Atoms in Strong Fields

    CERN Document Server

    Clark, Charles; Nayfeh, Munir

    1990-01-01

    This book collects the lectures given at the NATO Advanced Study Institute on "Atoms in Strong Fields", which took place on the island of Kos, Greece, during the two weeks of October 9-21,1988. The designation "strong field" applies here to an external electromagnetic field that is sufficiently strong to cause highly nonlinear alterations in atomic or molecular struc­ ture and dynamics. The specific topics treated in this volume fall into two general cater­ gories, which are those for which strong field effects can be studied in detail in terrestrial laboratories: the dynamics of excited states in static or quasi-static electric and magnetic fields; and the interaction of atoms and molecules with intense laser radiation. In both areas there exist promising opportunities for research of a fundamental nature. An electric field of even a few volts per centimeter can be very strong on the atom­ ic scale, if it acts upon a weakly bound state. The study of Rydberg states with high reso­ lution laser spectroscop...

  3. Electric Field Fluctuations in Water

    Science.gov (United States)

    Thorpe, Dayton; Limmer, David; Chandler, David

    2013-03-01

    Charge transfer in solution, such as autoionization and ion pair dissociation in water, is governed by rare electric field fluctuations of the solvent. Knowing the statistics of such fluctuations can help explain the dynamics of these rare events. Trajectories short enough to be tractable by computer simulation are virtually certain not to sample the large fluctuations that promote rare events. Here, we employ importance sampling techniques with classical molecular dynamics simulations of liquid water to study statistics of electric field fluctuations far from their means. We find that the distributions of electric fields located on individual water molecules are not in general gaussian. Near the mean this non-gaussianity is due to the internal charge distribution of the water molecule. Further from the mean, however, there is a previously unreported Bjerrum-like defect that stabilizes certain large fluctuations out of equilibrium. As expected, differences in electric fields acting between molecules are gaussian to a remarkable degree. By studying these differences, though, we are able to determine what configurations result not only in large electric fields, but also in electric fields with long spatial correlations that may be needed to promote charge separation.

  4. Vertical gradients of sunspot magnetic fields

    Science.gov (United States)

    Hagyard, M. J.; Teuber, D.; West, E. A.; Tandberg-Hanssen, E.; Henze, W., Jr.; Beckers, J. M.; Bruner, M.; Hyder, C. L.; Woodgate, B. E.

    1983-01-01

    The results of a Solar Maximum Mission (SMM) guest investigation to determine the vertical gradients of sunspot magnetic fields for the first time from coordinated observations of photospheric and transition-region fields are described. Descriptions are given of both the photospheric vector field of a sunspot, derived from observations using the NASA Marshall Space Flight Center vector magnetograph, and of the line-of-sight component in the transition region, obtained from the SMM Ultraviolet Spectrometer and Polarimeter instrument. On the basis of these data, vertical gradients of the line-of-sight magnetic field component are calculated using three methods. It is found that the vertical gradient of Bz is lower than values from previous studies and that the transition-region field occurs at a height of approximately 4000-6000 km above the photosphere.

  5. Studies in quantum field theory

    International Nuclear Information System (INIS)

    Bender, C.M.; Mandula, J.E.; Shrauner, J.E.

    1982-01-01

    Washington University is currently conducting research in many areas of high energy theoretical and mathematical physics. These areas include: strong-coupling approximation; classical solutions of non-Abelian gauge theories; mean-field approximation in quantum field theory; path integral and coherent state representations in quantum field theory; lattice gauge calculations; the nature of perturbation theory in large orders; quark condensation in QCD; chiral symmetry breaking; the l/N expansion in quantum field theory; effective potential and action in quantum field theories, including QCD

  6. Non-cyclic phases for neutrino oscillations in quantum field theory

    International Nuclear Information System (INIS)

    Blasone, Massimo; Capolupo, Antonio; Celeghini, Enrico; Vitiello, Giuseppe

    2009-01-01

    We show the presence of non-cyclic phases for oscillating neutrinos in the context of quantum field theory. Such phases carry information about the non-perturbative vacuum structure associated with the field mixing. By subtracting the condensate contribution of the flavor vacuum, the previously studied quantum mechanics geometric phase is recovered.

  7. Applying geophysical surveys for studying subsurface geology of monogenetic volcanic fields: the example of La Garrotxa Volcanic Field (NE of Iberian Peninsula)

    Science.gov (United States)

    Bolós, Xavier; Barde-Cabusson, Stéphanie; Pedrazzi, Dario; Martí, Joan; Casas, Albert; Lovera, Raúl; Nadal-Sala, Daniel

    2014-05-01

    Improving knowledge of the shallowest part of the feeding system of monogenetic volcanoes and the relationship with the subsurface geology is an important task. We applied high-precision geophysical techniques that are self-potential and electrical resistivity tomography, for the exploration of the uppermost part of the substrate of La Garrotxa Volcanic Field, which is part of the European Cenozoic Rift System. Previous geophysical studies carried out in the same area at a less detailed scale were aimed at identifying deeper structures, and together constitute the basis to establish volcanic susceptibility in La Garrotxa. Self-potential study allowed identifying key areas where electrical resistivity tomography could be conducted. Dykes and faults associated with several monogenetic cones were identified through the generation of resistivity models. The combined results confirm that shallow tectonics controlling the distribution of the foci of eruptive activity in this volcanic zone mainly correspond to NNW-SSE and accessorily by NNE-SSW Neogene extensional fissures and faults and concretely show the associated magmatic intrusions. These studies show that previous alpine tectonic structures played no apparent role in controlling the loci of this volcanism. Furthermore, the results obtained show that the changes in eruption dynamics occurring at different vents located at relatively short distances in this volcanic area can be controlled by shallow stratigraphical, structural, and hydrogeological features underneath these monogenetic volcanoes. This study was partially funded by the Beca Ciutat d'Olot en Ciències Naturals and the European Commission (FT7 Theme: ENV.2011.1.3.3-1; Grant 282759: "VUELCO").

  8. Gendered Choices : Fields of study of adolescents in the Netherlands

    NARCIS (Netherlands)

    van der Vleuten, M.

    2018-01-01

    Choosing a field of study is an important decision in determining future educational trajectories and occupations, and we know that boys and girls make different field of study choices. Girls are underrepresented in gender-stereotypical masculine fields like science and technology, whereas boys are

  9. Cadernos Pagu: Consolidating a Field of Studies

    Directory of Open Access Journals (Sweden)

    Iara Beleli

    2003-01-01

    Full Text Available As scientific publications are influential indicators and constitute disciplinary fields, this article reflects on the importance of Cadernos Pagu, published twice a year by Unicamp’s Núcleo de Estudos de Gênero [Gender Studies Center], as it has contributed to the consolidation of that field of studies both through de stimulation and diffusion of knowledge in the area in Brazil. Here gender is no conceived of as a theme, but rather as a categorical distinction, as a distinction between characteristics taken as feminine and masculine, that run through society and, as such, can be felt within any thematic frame.

  10. Dynamic surface deformation of silicone elastomers for management of marine biofouling: laboratory and field studies using pneumatic actuation.

    Science.gov (United States)

    Shivapooja, Phanindhar; Wang, Qiming; Szott, Lizzy M; Orihuela, Beatriz; Rittschof, Daniel; Zhao, Xuanhe; López, Gabriel P

    2015-01-01

    Many strategies have been developed to improve the fouling release (FR) performance of silicone coatings. However, biofilms inevitably build on these surfaces over time. Previous studies have shown that intentional deformation of silicone elastomers can be employed to detach biofouling species. In this study, inspired by the methods used in soft-robotic systems, controlled deformation of silicone elastomers via pneumatic actuation was employed to detach adherent biofilms. Using programmed surface deformation, it was possible to release > 90% of biofilm from surfaces in both laboratory and field environments. A higher substratum strain was required to remove biofilms accumulated in the field environment as compared with laboratory-grown biofilms. Further, the study indicated that substratum modulus influences the strain needed to de-bond biofilms. Surface deformation-based approaches have potential for use in the management of biofouling in a number of technological areas, including in niche applications where pneumatic actuation of surface deformation is feasible.

  11. Field emission study of MWCNT/conducting polymer nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Alvi, M.A., E-mail: maalvee@yahoo.co.in [Department of Physics, King Abdulaziz University, Jeddah-21589 (Saudi Arabia); Al-Ghamdi, A.A. [Department of Physics, King Abdulaziz University, Jeddah-21589 (Saudi Arabia); Husain, M. [Department of Physics, Jamia Millia Islamia, New Delhi-110025 (India)

    2014-12-01

    MWCNTs/Polypyrrole nanocomposites were synthesized by solution mixing method. These synthesized nanocomposites were studied carefully by Raman Spectroscopy and Scanning Electron Microscopy measurements. The field emission study of MWCNTs/Polypyrrole nanocomposites were performed in diode arrangement under vacuum of the order of 10{sup −5} Torr. The emission current under exploration depends on applied voltage. The prepared nanocomposites depict low turn-on field at 1.4 V/μm that reaches to a maximum emission current density 0.020 mA/cm{sup 2} at 2.4 V/µm, which is calculated from the graph of current density (J) against the applied electric field (E) and from Fowler–Nordheim (F–N) plot.

  12. Subsequent pregnancy outcome after previous foetal death

    NARCIS (Netherlands)

    Nijkamp, J. W.; Korteweg, F. J.; Holm, J. P.; Timmer, A.; Erwich, J. J. H. M.; van Pampus, M. G.

    Objective: A history of foetal death is a risk factor for complications and foetal death in subsequent pregnancies as most previous risk factors remain present and an underlying cause of death may recur. The purpose of this study was to evaluate subsequent pregnancy outcome after foetal death and to

  13. Mean-field lattice trees

    NARCIS (Netherlands)

    Borgs, C.; Chayes, J.T.; Hofstad, van der R.W.; Slade, G.

    1999-01-01

    We introduce a mean-field model of lattice trees based on embeddings into d of abstract trees having a critical Poisson offspring distribution. This model provides a combinatorial interpretation for the self-consistent mean-field model introduced previously by Derbez and Slade [9], and provides an

  14. Common Group Problems: A Field Study.

    Science.gov (United States)

    Weinberg, Sanford B.; And Others

    1981-01-01

    A field study of a naturally functioning group (N=125) was conducted to identify common group problems. Trained observers attended group meetings and described the problems encountered. Difficulties of cohesion, leadership, sub-group formation, and personality conflict were identified. (RC)

  15. Field-modulation spectroscopy of pentacene thin films using field-effect devices: Reconsideration of the excitonic structure

    Science.gov (United States)

    Haas, Simon; Matsui, Hiroyuki; Hasegawa, Tatsuo

    2010-10-01

    We report pure electric-field effects on the excitonic absorbance of pentacene thin films as measured by unipolar field-effect devices that allowed us to separate the charge accumulation effects. The field-modulated spectra between 1.8 and 2.6 eV can be well fitted with the first derivative curve of Frenkel exciton absorption and its vibronic progression, and at higher energy a field-induced feature appears at around 2.95 eV. The results are in sharp contrast to the electroabsorption spectra reported by Sebastian in previous studies [Chem. Phys. 61, 125 (1981)10.1016/0301-0104(81)85055-0], and leads us to reconsider the excitonic structure including the location of charge-transfer excitons. Nonlinear π -electronic response is discussed based on second-order electro-optic (Kerr) spectra.

  16. The biomechanics of running in athletes with previous hamstring injury: A case-control study.

    Science.gov (United States)

    Daly, C; Persson, U McCarthy; Twycross-Lewis, R; Woledge, R C; Morrissey, D

    2016-04-01

    Hamstring injury is prevalent with persistently high reinjury rates. We aim to inform hamstring rehabilitation by exploring the electromyographic and kinematic characteristics of running in athletes with previous hamstring injury. Nine elite male Gaelic games athletes who had returned to sport after hamstring injury and eight closely matched controls sprinted while lower limb kinematics and muscle activity of the previously injured biceps femoris, bilateral gluteus maximus, lumbar erector spinae, rectus femoris, and external oblique were recorded. Intergroup comparisons of muscle activation ratios and kinematics were performed. Previously injured athletes demonstrated significantly reduced biceps femoris muscle activation ratios with respect to ipsilateral gluteus maximus (maximum difference -12.5%, P = 0.03), ipsilateral erector spinae (maximum difference -12.5%, P = 0.01), ipsilateral external oblique (maximum difference -23%, P = 0.01), and contralateral rectus femoris (maximum difference -22%, P = 0.02) in the late swing phase. We also detected sagittal asymmetry in hip flexion (maximum 8°, P = 0.01), pelvic tilt (maximum 4°, P = 0.02), and medial rotation of the knee (maximum 6°, P = 0.03) effectively putting the hamstrings in a lengthened position just before heel strike. Previous hamstring injury is associated with altered biceps femoris associated muscle activity and potentially injurious kinematics. These deficits should be considered and addressed during rehabilitation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Influence of field study on learning and attitudes toward science

    Science.gov (United States)

    Brackney, David L.

    In an effort to improve attitudes toward science and academic achievement among college students who are non-science majors, an informal science educational experience in the form of a natural science field study course was created. The purpose of this study was to investigate the impact of a field study experience on student science attitudes and achievement. Outcomes from the field study groups were compared to students who enrolled in a traditional lecture/lab course. Academic achievement was measured via pre and posttest measures of geologic knowledge. Attitudes toward science were measured with a Science Attitudes Survey that utilized Likert-scale type items in the instrument. To explore student impressions and reactions to participating in the field study experience, interviews were conducted with open-ended questions. Patterns of responses were identified to explore common themes. Field study participants were found to have significantly higher gains from pre to posttest scores compared with the gains made by students who participated in a formal Earth Science course. There was no significant difference found in overall attitudes toward science and technology as measured with this attitudes survey between students who participated in the two formats of courses over the last five years. However, comments shared by participants in the field study through interviews suggest that their attitudes toward science had in fact been affected in positive ways. Other patterns of responses indicate positive impacts made on students on a number of fronts including affective, cognitive, and social interactions. All students interviewed rated the field study experience as valuable educationally or extremely valuable educationally.

  18. Dexamethasone intravitreal implant in previously treated patients with diabetic macular edema : Subgroup analysis of the MEAD study

    OpenAIRE

    Augustin, A.J.; Kuppermann, B.D.; Lanzetta, P.; Loewenstein, A.; Li, X.; Cui, H.; Hashad, Y.; Whitcup, S.M.; Abujamra, S.; Acton, J.; Ali, F.; Antoszyk, A.; Awh, C.C.; Barak, A.; Bartz-Schmidt, K.U.

    2015-01-01

    Background Dexamethasone intravitreal implant 0.7?mg (DEX 0.7) was approved for treatment of diabetic macular edema (DME) after demonstration of its efficacy and safety in the MEAD registration trials. We performed subgroup analysis of MEAD study results to evaluate the efficacy and safety of DEX 0.7 treatment in patients with previously treated DME. Methods Three-year, randomized, sham-controlled phase 3 study in patients with DME, best-corrected visual acuity (BCVA) of 34?68 Early Treatment...

  19. Subsequent childbirth after a previous traumatic birth.

    Science.gov (United States)

    Beck, Cheryl Tatano; Watson, Sue

    2010-01-01

    Nine percent of new mothers in the United States who participated in the Listening to Mothers II Postpartum Survey screened positive for meeting the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for posttraumatic stress disorder after childbirth. Women who have had a traumatic birth experience report fewer subsequent children and a longer length of time before their second baby. Childbirth-related posttraumatic stress disorder impacts couples' physical relationship, communication, conflict, emotions, and bonding with their children. The purpose of this study was to describe the meaning of women's experiences of a subsequent childbirth after a previous traumatic birth. Phenomenology was the research design used. An international sample of 35 women participated in this Internet study. Women were asked, "Please describe in as much detail as you can remember your subsequent pregnancy, labor, and delivery following your previous traumatic birth." Colaizzi's phenomenological data analysis approach was used to analyze the stories of the 35 women. Data analysis yielded four themes: (a) riding the turbulent wave of panic during pregnancy; (b) strategizing: attempts to reclaim their body and complete the journey to motherhood; (c) bringing reverence to the birthing process and empowering women; and (d) still elusive: the longed-for healing birth experience. Subsequent childbirth after a previous birth trauma has the potential to either heal or retraumatize women. During pregnancy, women need permission and encouragement to grieve their prior traumatic births to help remove the burden of their invisible pain.

  20. Application of integrated petroleum reservoir study for intervention and field development program in western onshore field, India

    Directory of Open Access Journals (Sweden)

    Vijai Kumar Baskaran

    2017-12-01

    Full Text Available In this research, an integrated reservoir study is performed in the J#Field (J-Oil Field of western onshore, India to evaluate its additional reserves expectations and implement field developments plan using waterflood pilot program. The target strata includes two formations of Paleogene, which is about 3600 ft, namely G#Fm (G-Formation of the Eocene and T#Fm (T-Formation of Oligocene, subdivided into 11 zones. Based on these results, an attempt was made to construct of an optimization plan to exploit it, taking into account that the field is producing since 1947, with a cumulative production of 183.5 MMbbl and an overall recovery factor of 28% until January 2016. On the basis of the potential evaluation and geological modeling, blocks J48 and J45 were simulated, and the remaining oil distribution characteristics in two blocks were studied after history match. The work includes the stratigraphic studies, seismic study, logging interpretation, sedimentary facies modeling, three dimensional geological modeling, simulations for waterflooding, and future field development plans.

  1. Non-ionizing radiation exposure: electric field strength measurement ...

    African Journals Online (AJOL)

    In this research, the measured values are compared with the international standard recommended by ICNIRP then were also compared with previous study from several locations around Malaysia. The result shows an increase in the values of electromagnetic field radiation. The result of this study could be used for health ...

  2. Evaluation of a rapid dipstick (Crystal VC for the diagnosis of cholera in Zanzibar and a comparison with previous studies.

    Directory of Open Access Journals (Sweden)

    Benedikt Ley

    Full Text Available The gold standard for the diagnosis of cholera is stool culture, but this requires laboratory facilities and takes at least 24 hours. A rapid diagnostic test (RDT that can be used by minimally trained staff at treatment centers could potentially improve the reporting and management of cholera outbreaks.We evaluated the Crystal VC™ RDT under field conditions in Zanzibar in 2009. Patients presenting to treatment centers with watery diarrhea provided a stool sample for rapid diagnostic testing. Results were compared to stool culture performed in a reference laboratory. We assessed the overall performance of the RDT and evaluated whether previous intake of antibiotics, intravenous fluids, location of testing, and skill level of the technician affected the RDT results.We included stool samples from 624 patients. Compared to culture, the overall sensitivity of the RDT was 93.1% (95%CI: 88.7 to 96.2%, specificity was 49.2% (95%CI: 44.3 to 54.1%, the positive predictive value was 47.0% (95%CI: 42.1 to 52.0% and the negative predictive value was 93.6% (95%CI: 89.6 to 96.5%. The overall false positivity rate was 50.8% (213/419; fieldworkers frequently misread very faint test lines as positive.The observed sensitivity of the Crystal VC RDT evaluated was similar compared to earlier versions, while specificity was poorer. The current version of the RDT could potentially be used as a screening tool in the field. Because of the high proportion of false positive results when field workers test stool specimens, positive results will need to be confirmed with stool culture.

  3. Study of condensate composition during field processing of gas of the Shatlyk field

    Energy Technology Data Exchange (ETDEWEB)

    Kuldzhayev, B.A.; Annamukhamedov, M.B.; Makarov, V.V.; Serbnenko, S.R.; Talalayev, Ye.I.

    1983-01-01

    Studies were made of the composition and properties of condensates from field separators of the East Shatlyk field. The expediency is shown of separate collection of the condensates into a separate container and used for local needs as the diesel fuel. The condensates from the UNTS separators are used as chemical raw material to produce the lowest olephins by pyrolysis of gas-oil fraction and normal paraffins from kerosene-gas-oil part to obtain the protein-vitamin concentrates.

  4. Colour vision and light sensitivity in tunnel workers previously exposed to acrylamide and N-methylolacrylamide containing grouting agents.

    Science.gov (United States)

    Goffeng, Lars Ole; Kjuus, Helge; Heier, Mona Skard; Alvestrand, Monica; Ulvestad, Bente; Skaug, Vidar

    2008-01-01

    The aim of the study was to examine possible persisting visual system effects in tunnel workers previously exposed to acrylamide and N-methylolacrylamide during grouting work. Visual field light sensitivity threshold and colour vision has been examined among 44 tunnel workers 2-10 years after exposure to acrylamide and N-methylolacrylamide containing grouting agents. Forty-four tunnel workers not involved in grouting operations served as control group. Information on exposure and background variables was obtained for all participants from a questionnaire. Visual light sensitivity threshold was measured using Humphrey Visual Field Static Perimeter 740, program 30-2 Fastpack, with red stimuli on white background, and colour vision, using Lanthony D-15 Desaturated Color test. Based on D-15d test results, colour confusion index (CCI), and a severity index (C-index) was calculated. The exposed group had a significantly higher threshold for detecting single stimuli in all parts of the inner 30 degrees of the visual field compared to the control group. The foveal threshold group difference was 1.4 dB (p=0.002) (mean value, both eyes). On the Lanthony 15 Hue Desaturated test, the exposed subjects made more errors in sorting blue colours, and a statistically significant increase in C-index was observed. Surrogate measures for duration and intensity of exposure gave no further improvement of the model. The results indicate slightly reduced light sensitivity and reduced colour discrimination among the exposed subjects compared to the controls. The findings may be due to previous exposure to acrylamide containing grouts among the tunnel workers.

  5. The Field Trip Book: Study Travel Experiences in Social Studies

    Science.gov (United States)

    Morris, Ronald V.

    2010-01-01

    Looking for social studies adventures to help students find connections to democratic citizenship? Look no further! This book provides just the answer teachers need for engaging students in field trips as researching learners with emphasis on interdisciplinary social studies plus skills in collecting and reporting data gathered from field…

  6. Jupiter Environmental Research & Field Studies Academy.

    Science.gov (United States)

    Huttemeyer, Bob

    1996-01-01

    Describes the development and workings of the Jupiter Environmental Research and Field Studies Academy that focuses on enabling both teachers and students to participate in real-life learning experiences. Discusses qualifications for admittance, curriculum, location, ongoing projects, students, academics, preparation for life, problem solving, and…

  7. Challenging previous conceptions of vegetarianism and eating disorders.

    Science.gov (United States)

    Fisak, B; Peterson, R D; Tantleff-Dunn, S; Molnar, J M

    2006-12-01

    The purpose of this study was to replicate and expand upon previous research that has examined the potential association between vegetarianism and disordered eating. Limitations of previous research studies are addressed, including possible low reliability of measures of eating pathology within vegetarian samples, use of only a few dietary restraint measures, and a paucity of research examining potential differences in body image and food choice motives of vegetarians versus nonvegetarians. Two hundred and fifty-six college students completed a number of measures of eating pathology and body image, and a food choice motives questionnaire. Interestingly, no significant differences were found between vegetarians and nonvegetarians in measures of eating pathology or body image. However, significant differences in food choice motives were found. Implications for both researchers and clinicians are discussed.

  8. Further studies on the problems of geomagnetic field intensity determination from archaeological baked clay materials

    Science.gov (United States)

    Kostadinova-Avramova, M.; Kovacheva, M.

    2015-10-01

    Archaeological baked clay remains provide valuable information about the geomagnetic field in historical past, but determination of the geomagnetic field characteristics, especially intensity, is often a difficult task. This study was undertaken to elucidate the reasons for unsuccessful intensity determination experiments obtained from two different Bulgarian archaeological sites (Nessebar - Early Byzantine period and Malenovo - Early Iron Age). With this aim, artificial clay samples were formed in the laboratory and investigated. The clay used for the artificial samples preparation differs according to its initial state. Nessebar clay was baked in the antiquity, but Malenovo clay was raw, taken from the clay deposit near the site. The obtained artificial samples were repeatedly heated eight times in known magnetic field to 700 °C. X-ray diffraction analyses and rock-magnetic experiments were performed to obtain information about the mineralogical content and magnetic properties of the initial and laboratory heated clays. Two different protocols were applied for the intensity determination-Coe version of Thellier and Thellier method and multispecimen parallel differential pTRM protocol. Various combinations of laboratory fields and mutual positions of the directions of laboratory field and carried thermoremanence were used in the performed Coe experiment. The obtained results indicate that the failure of this experiment is probably related to unfavourable grain sizes of the prevailing magnetic carriers combined with the chosen experimental conditions. The multispecimen parallel differential pTRM protocol in its original form gives excellent results for the artificial samples, but failed for the real samples (samples coming from previously studied kilns of Nessebar and Malenovo sites). Obviously the strong dependence of this method on the homogeneity of the used subsamples hinders its implementation in its original form for archaeomaterials. The latter are often

  9. Field evaporation of ZnO: A first-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Yu, E-mail: yuxia@dal.ca; Karahka, Markus; Kreuzer, H. J. [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 3J5 (Canada)

    2015-07-14

    With recent advances in atom probe tomography of insulators and semiconductors, there is a need to understand high electrostatic field effects in these materials as well as the details of field evaporation. We use density functional theory to study field effects in ZnO clusters calculating the potential energy curves, the local field distribution, the polarizability, and the dielectric constant as a function of field strength. We confirm that, as in MgO, the HOMO-LUMO gap of a ZnO cluster closes at the evaporation field strength signaling field-induced metallization of the insulator. Following the structural changes in the cluster at the evaporation field strength, we can identify the field evaporated species, in particular, we show that the most abundant ion, Zn{sup 2+}, is NOT post-ionized but leaves the surface as 2+ largely confirming the experimental observations. Our results also help to explain problems related to stoichiometry in the mass spectra measured in atom probe tomography.

  10. Electrosensitization Increases Antitumor Effectiveness of Nanosecond Pulsed Electric Fields In Vivo

    OpenAIRE

    Muratori, Claudia; Pakhomov, Andrei G.; Heller, Loree; Casciola, Maura; Gianulis, Elena; Grigoryev, Sergey; Xiao, Shu; Pakhomova, O. N.

    2017-01-01

    Nanosecond pulsed electric fields are emerging as a new modality for tissue and tumor ablation. We previously reported that cells exposed to pulsed electric fields develop hypersensitivity to subsequent pulsed electric field applications. This phenomenon, named electrosensitization, is evoked by splitting the pulsed electric field treatment in fractions (split-dose treatments) and causes in vitro a 2- to 3-fold increase in cytotoxicity. The aim of this study was to show the benefit of split-d...

  11. Auditory evoked field measurement using magneto-impedance sensors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, K., E-mail: o-kabou@echo.nuee.nagoya-u.ac.jp; Tajima, S.; Song, D.; Uchiyama, T. [Graduate School of Engineering, Nagoya University, Nagoya (Japan); Hamada, N.; Cai, C. [Aichi Steel Corporation, Tokai (Japan)

    2015-05-07

    The magnetic field of the human brain is extremely weak, and it is mostly measured and monitored in the magnetoencephalography method using superconducting quantum interference devices. In this study, in order to measure the weak magnetic field of the brain, we constructed a Magneto-Impedance sensor (MI sensor) system that can cancel out the background noise without any magnetic shield. Based on our previous studies of brain wave measurements, we used two MI sensors in this system for monitoring both cerebral hemispheres. In this study, we recorded and compared the auditory evoked field signals of the subject, including the N100 (or N1) and the P300 (or P3) brain waves. The results suggest that the MI sensor can be applied to brain activity measurement.

  12. Increased complexity in aesthetic field theory

    International Nuclear Information System (INIS)

    Muraskin, M.; Ring, B.

    1977-01-01

    The program of looking for increased complexity within aesthetic field theory is continued. We study a solution with five planar maxima and minima. Another solution in which one counted 19 planar maxima and minima is also studied. This latter solution was obtained by modifying previous principles by allowing for an arbitrariness associated with the integration path in conjunction with the equation GAMMA/sub jk;1//sup i/ = 0

  13. A previous hamstring injury affects kicking mechanics in soccer players.

    Science.gov (United States)

    Navandar, Archit; Veiga, Santiago; Torres, Gonzalo; Chorro, David; Navarro, Enrique

    2018-01-10

    Although the kicking skill is influenced by limb dominance and sex, how a previous hamstring injury affects kicking has not been studied in detail. Thus, the objective of this study was to evaluate the effect of sex and limb dominance on kicking in limbs with and without a previous hamstring injury. 45 professional players (males: n=19, previously injured players=4, age=21.16 ± 2.00 years; females: n=19, previously injured players=10, age=22.15 ± 4.50 years) performed 5 kicks each with their preferred and non-preferred limb at a target 7m away, which were recorded with a three-dimensional motion capture system. Kinematic and kinetic variables were extracted for the backswing, leg cocking, leg acceleration and follow through phases. A shorter backswing (20.20 ± 3.49% vs 25.64 ± 4.57%), and differences in knee flexion angle (58 ± 10o vs 72 ± 14o) and hip flexion velocity (8 ± 0rad/s vs 10 ± 2rad/s) were observed in previously injured, non-preferred limb kicks for females. A lower peak hip linear velocity (3.50 ± 0.84m/s vs 4.10 ± 0.45m/s) was observed in previously injured, preferred limb kicks of females. These differences occurred in the backswing and leg-cocking phases where the hamstring muscles were the most active. A variation in the functioning of the hamstring muscles and that of the gluteus maximus and iliopsoas in the case of a previous injury could account for the differences observed in the kicking pattern. Therefore, the effects of a previous hamstring injury must be considered while designing rehabilitation programs to re-educate kicking movement.

  14. Maximum repulsed magnetization of a bulk superconductor with low pulsed field

    International Nuclear Information System (INIS)

    Tsuchimoto, M.; Kamijo, H.; Fujimoto, H.

    2005-01-01

    Pulsed field magnetization of a bulk high-T c superconductor (HTS) is important technique especially for practical applications of a bulk superconducting magnet. Full magnetization is not obtained for low pulsed field and trapped field is decreased by reversed current in the HTS. The trapped field distribution by repulsed magnetization was previously reported in experiments with temperature control. In this study, repulsed magnetization technique with the low pulsed field is numerically analyzed under assumption of variable shielding current by the temperature control. The shielding current densities are discussed to obtain maximum trapped field by two times of low pulsed field magnetizations

  15. Rio Vista gas leak study: Belleaire Gas Field, California

    International Nuclear Information System (INIS)

    Wilkey, P.L.

    1992-08-01

    The Rio Vista gas leak study evaluated methods for remotely sensing gas leaks from buried pipelines and developed methods to elucidate methane transport and microbial oxidation in soils. Remote-sensing methods were evaluated by singing gas leaks along an abandoned Pacific Gas and Electric (PG ampersand E) gas field collection line in northern California and applying surface-based and airborne remote-sensing techniques in the field, including thermal imaging, laser imaging, and multispectral imagery. The remote-sensing techniques exhibited limitations in range and in their ability to correlate with ground truth data. To elucidate methane transport and microbial oxidation in soils, a study of a controlled leak permitted field testing of methods so that such processes could be monitored and evaluated. Monitoring and evaluation techniques included (1) field measurement of soil-gas concentrations, temperatures, and pressures; (2) laboratory measurement of soil physical/chemical properties and activity of methane-oxidizing microorganisms by means of field samples; and (3) development of a preliminary numerical analysis technique for combined soil-gas transport/methane oxidation. Soil-gas concentrations at various depths responded rapidly to the high rate of gas leakage. The number of methane-oxidizing microorganisms in site soils rapidly increased when the gas leak was initiated and decreased after the leak was terminated. The preliminary field, laboratory, and numerical analysis techniques tested for this study of a controlled gas leak could be successfully applied to future studies of gas leaks. Because soil-gas movement is rapid and temporally variable, the use of several complementary techniques that permit generalization of site-specific results is favored

  16. A grounded theory study on the academic success of undergraduate women in science, engineering, and mathematics fields at a private, research university

    Science.gov (United States)

    Hroch, Amber Michelle

    2011-12-01

    This grounded theory study revealed the common factors of backgrounds, strategies, and motivators in academically successful undergraduate women in science, engineering, and mathematics (SEM) fields at a private, research university in the West. Data from interviews with 15 women with 3.25 or better grade point averages indicated that current academic achievement in their college SEM fields can be attributed to previous academic success, self awareness, time management and organizational skills, and maintaining a strong support network. Participants were motivated by an internal drive to academically succeed and attend graduate school. Recommendations are provided for professors, advisors, and student affairs professionals.

  17. In-situ electric field and current density in Japanese male and female models for uniform magnetic field exposures

    International Nuclear Information System (INIS)

    Hirata, A.; Wake, K.; Watanabe, S.; Taki, M.

    2009-01-01

    The present study quantified the in situ electric field and induced current density in anatomically based numeric Japanese male and female models for exposure to extremely low-frequency magnetic fields. A quasi-static FDTD method was applied to analyse this problem. The computational results obtained herein reveal that the 99. percentile value of the in situ electric field in the nerve tissue and the current density averaged over an area of 1 cm 2 of the nerve tissue (excluding non-nerve tissues in the averaging region) in the female models were less than 35 and 25%, respectively. These induced quantities in the Japanese models were smaller than those for European models reported in a previous study, which is mainly due to the difference in cross-sectional area of the body. (authors)

  18. Effects of magnetic field exposure on open field behaviour and nociceptive responses in mice.

    Science.gov (United States)

    Del Seppia, Cristina; Mezzasalma, Lorena; Choleris, Elena; Luschi, Paolo; Ghione, Sergio

    2003-09-15

    Results of previous studies have shown that nociceptive sensitivity in male C57 mice is enhanced by exposure to a regular 37 Hz or an irregularly varying (field. In order to test whether these fields affect more generally mouse behaviour, we placed Swiss CD-1 mice in a novel environment (open field test) and exposed them for 2 h to these two different magnetic field conditions. Hence, we analysed how duration and time course of various behavioural patterns (i.e. exploration, rear, edge chew, self-groom, sit, walk and sleep) and nociceptive sensitivity had been affected by such exposure. Nociceptive sensitivity was significantly greater in magnetically treated mice than in controls. The overall time spent in exploratory activities was significantly shorter in both magnetically treated groups (time), than in controls (42%). Conversely, the time spent in sleeping was markedly longer in the treated groups (both 27% of total time) than in controls (11%). These results suggest that exposure to altered magnetic fields induce a more rapid habituation to a novel environment.

  19. Hooking the geographer in children with field-based studies

    Energy Technology Data Exchange (ETDEWEB)

    Krall, F; Sorgman, M I; Uhlenberg, D M

    1978-03-01

    Survey report:Field studies of environmental subjects are helpful in understanding the relationship between humans and their environment. Geography provides an interdisciplinary approach through which elementary children can gain this understanding. Suggested field studies revolve around the school grounds, communities, and homes of the children involved. Projects include studies of natural communities, human communities, solid wastes, and energy conservation. The projects are designed to stimulate broader inquiry by the children. (4 references)

  20. Force-field dependence of the conformational properties of ,-dimethoxypolyethylene glycol

    NARCIS (Netherlands)

    Winger, Moritz; de Vries, Alex H.; van Gunsteren, Wilfred F.

    2009-01-01

    A molecular dynamics (MD) study of ,-dimethoxypolyethylene glycol has been carried out under various conditions with respect to solvent composition, ionic strength, chain length, force field and temperature. A previous MD study on a 15-mer of polyethyleneglycol (PEG) suggested a helical equilibrium

  1. Trapped magnetic field measurements on HTS bulk by peak controlled pulsed field magnetization

    International Nuclear Information System (INIS)

    Ida, Tetsuya; Watasaki, Masahiro; Kimura, Yosuke; Miki, Motohiro; Izumi, Mitsuru

    2010-01-01

    For the past several years, we have studied the high-temperature superconducting (HTS) synchronous motor assembled with melt-textured Gd-Ba-Cu-O bulk magnets. If the single pulse field magnetizes a bulk effectively, size of electrical motor will become small for the strong magnetic field of the HTS magnets without reducing output power of motor. In the previous study, we showed that the HTS bulk was magnetized to excellent cone-shape magnetic field distribution by using the waveform control pulse magnetization (WCPM) method. The WCPM technique made possible the active control of the waveform on which magnetic flux motion depended. We generated the pulse waveform with controlled risetime for HTS bulk magnetization to suppress the magnetic flux motion which decreases magnetization efficiency. The pulsed maximum magnetic flux density with slow risetime is not beyond the maximum magnetic flux density which is trapped by the static field magnetization. But, as for applying the pulse which has fast risetime, the magnetic flux which exceed greatly the threshold penetrates the bulk and causes the disorder of the trapped magnetic distribution. This fact suggests the possibility that the threshold at pulsed magnetization influences the dynamic magnetic flux motion. In this study, Gd-Ba-Cu-O bulk is magnetized by the controlled arbitrary trapezoidal shape pulse, of which the maximum magnetic flux density is controlled not to exceed the threshold. We will present the trapped magnetic characteristics and the technique to generate the controlled pulsed field.

  2. No discrimination against previous mates in a sexually cannibalistic spider

    Science.gov (United States)

    Fromhage, Lutz; Schneider, Jutta M.

    2005-09-01

    In several animal species, females discriminate against previous mates in subsequent mating decisions, increasing the potential for multiple paternity. In spiders, female choice may take the form of selective sexual cannibalism, which has been shown to bias paternity in favor of particular males. If cannibalistic attacks function to restrict a male's paternity, females may have little interest to remate with males having survived such an attack. We therefore studied the possibility of female discrimination against previous mates in sexually cannibalistic Argiope bruennichi, where females almost always attack their mate at the onset of copulation. We compared mating latency and copulation duration of males having experienced a previous copulation either with the same or with a different female, but found no evidence for discrimination against previous mates. However, males copulated significantly shorter when inserting into a used, compared to a previously unused, genital pore of the female.

  3. Abiraterone in metastatic prostate cancer without previous chemotherapy

    NARCIS (Netherlands)

    Ryan, Charles J.; Smith, Matthew R.; de Bono, Johann S.; Molina, Arturo; Logothetis, Christopher J.; de Souza, Paul; Fizazi, Karim; Mainwaring, Paul; Piulats, Josep M.; Ng, Siobhan; Carles, Joan; Mulders, Peter F. A.; Basch, Ethan; Small, Eric J.; Saad, Fred; Schrijvers, Dirk; van Poppel, Hendrik; Mukherjee, Som D.; Suttmann, Henrik; Gerritsen, Winald R.; Flaig, Thomas W.; George, Daniel J.; Yu, Evan Y.; Efstathiou, Eleni; Pantuck, Allan; Winquist, Eric; Higano, Celestia S.; Taplin, Mary-Ellen; Park, Youn; Kheoh, Thian; Griffin, Thomas; Scher, Howard I.; Rathkopf, Dana E.; Boyce, A.; Costello, A.; Davis, I.; Ganju, V.; Horvath, L.; Lynch, R.; Marx, G.; Parnis, F.; Shapiro, J.; Singhal, N.; Slancar, M.; van Hazel, G.; Wong, S.; Yip, D.; Carpentier, P.; Luyten, D.; de Reijke, T.

    2013-01-01

    Abiraterone acetate, an androgen biosynthesis inhibitor, improves overall survival in patients with metastatic castration-resistant prostate cancer after chemotherapy. We evaluated this agent in patients who had not received previous chemotherapy. In this double-blind study, we randomly assigned

  4. Secondary recurrent miscarriage is associated with previous male birth.

    LENUS (Irish Health Repository)

    Ooi, Poh Veh

    2012-01-31

    Secondary recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses after delivery of a viable infant. Previous reports suggest that a firstborn male child is associated with less favourable subsequent reproductive potential, possibly due to maternal immunisation against male-specific minor histocompatibility antigens. In a retrospective cohort study of 85 cases of secondary RM we aimed to determine if secondary RM was associated with (i) gender of previous child, maternal age, or duration of miscarriage history, and (ii) increased risk of pregnancy complications. Fifty-three women (62.0%; 53\\/85) gave birth to a male child prior to RM compared to 32 (38.0%; 32\\/85) who gave birth to a female child (p=0.002). The majority (91.7%; 78\\/85) had uncomplicated, term deliveries and normal birth weight neonates, with one quarter of the women previously delivered by Caesarean section. All had routine RM investigations and 19.0% (16\\/85) had an abnormal result. Fifty-seven women conceived again and 33.3% (19\\/57) miscarried, but there was no significant difference in failure rates between those with a previous male or female child (13\\/32 vs. 6\\/25, p=0.2). When patients with abnormal results were excluded, or when women with only one previous child were considered, there was still no difference in these rates. A previous male birth may be associated with an increased risk of secondary RM but numbers preclude concluding whether this increases recurrence risk. The suggested association with previous male birth provides a basis for further investigations at a molecular level.

  5. Secondary recurrent miscarriage is associated with previous male birth.

    LENUS (Irish Health Repository)

    Ooi, Poh Veh

    2011-01-01

    Secondary recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses after delivery of a viable infant. Previous reports suggest that a firstborn male child is associated with less favourable subsequent reproductive potential, possibly due to maternal immunisation against male-specific minor histocompatibility antigens. In a retrospective cohort study of 85 cases of secondary RM we aimed to determine if secondary RM was associated with (i) gender of previous child, maternal age, or duration of miscarriage history, and (ii) increased risk of pregnancy complications. Fifty-three women (62.0%; 53\\/85) gave birth to a male child prior to RM compared to 32 (38.0%; 32\\/85) who gave birth to a female child (p=0.002). The majority (91.7%; 78\\/85) had uncomplicated, term deliveries and normal birth weight neonates, with one quarter of the women previously delivered by Caesarean section. All had routine RM investigations and 19.0% (16\\/85) had an abnormal result. Fifty-seven women conceived again and 33.3% (19\\/57) miscarried, but there was no significant difference in failure rates between those with a previous male or female child (13\\/32 vs. 6\\/25, p=0.2). When patients with abnormal results were excluded, or when women with only one previous child were considered, there was still no difference in these rates. A previous male birth may be associated with an increased risk of secondary RM but numbers preclude concluding whether this increases recurrence risk. The suggested association with previous male birth provides a basis for further investigations at a molecular level.

  6. Planned waveguide electric field breakdown studies

    International Nuclear Information System (INIS)

    Wang Faya; Li Zenghai

    2012-01-01

    This paper presents an experimental setup for X-band rf breakdown studies. The setup is composed of a section of WR90 waveguide with a tapered pin located at the middle of the waveguide E-plane. Another pin is used to rf match the waveguide so it operates in a travelling wave mode. By adjusting the penetration depth of the tapered pin, different surface electric field enhancements can be obtained. The setup will be used to study the rf breakdown rate dependence on power flow in the waveguide for a constant maximum surface electric field on the pin. Two groups of pins have been designed. The Q of one group is different and very low. The other has a similar Q. With the test of the two groups of pins, we should be able to discern how the net power flow and Q affect the breakdown. Furthermore, we will apply an electron beam treatment to the pins to study its effect on breakdown. Overall, these experiments should be very helpful in understanding rf breakdown phenomena and could significantly benefit the design of high gradient accelerator structures.

  7. Field cage studies and progressive evaluation of genetically-engineered mosquitoes.

    Directory of Open Access Journals (Sweden)

    Luca Facchinelli

    Full Text Available A genetically-engineered strain of the dengue mosquito vector Aedes aegypti, designated OX3604C, was evaluated in large outdoor cage trials for its potential to improve dengue prevention efforts by inducing population suppression. OX3604C is engineered with a repressible genetic construct that causes a female-specific flightless phenotype. Wild-type females that mate with homozygous OX3604C males will not produce reproductive female offspring. Weekly introductions of OX3604C males eliminated all three targeted Ae. aegypti populations after 10-20 weeks in a previous laboratory cage experiment. As part of the phased, progressive evaluation of this technology, we carried out an assessment in large outdoor field enclosures in dengue endemic southern Mexico.OX3604C males were introduced weekly into field cages containing stable target populations, initially at 10:1 ratios. Statistically significant target population decreases were detected in 4 of 5 treatment cages after 17 weeks, but none of the treatment populations were eliminated. Mating competitiveness experiments, carried out to explore the discrepancy between lab and field cage results revealed a maximum mating disadvantage of up 59.1% for OX3604C males, which accounted for a significant part of the 97% fitness cost predicted by a mathematical model to be necessary to produce the field cage results.Our results indicate that OX3604C may not be effective in large-scale releases. A strain with the same transgene that is not encumbered by a large mating disadvantage, however, could have improved prospects for dengue prevention. Insights from large outdoor cage experiments may provide an important part of the progressive, stepwise evaluation of genetically-engineered mosquitoes.

  8. Evaluation of Fast-Time Wake Models Using Denver 2006 Field Experiment Data

    Science.gov (United States)

    Ahmad, Nash’at N.; Pruis, Matthew J.

    2015-01-01

    The National Aeronautics and Space Administration conducted a series of wake vortex field experiments at Denver in 2003, 2005, and 2006. This paper describes the lidar wake vortex measurements and associated meteorological data collected during the 2006 deployment, and includes results of recent reprocessing of the lidar data using a new wake vortex algorithm and estimates of the atmospheric turbulence using a new algorithm to estimate eddy dissipation rate from the lidar data. The configuration and set-up of the 2006 field experiment allowed out-of-ground effect vortices to be tracked in lateral transport further than any previous campaign and thereby provides an opportunity to study long-lived wake vortices in moderate to low crosswinds. An evaluation of NASA's fast-time wake vortex transport and decay models using the dataset shows similar performance as previous studies using other field data.

  9. Program Plan: field radionuclide migration studies in Climax granite

    International Nuclear Information System (INIS)

    Isherwood, D.; Raber, E.; Coles, D.; Stone, R.

    1980-01-01

    This Program Plan describes the field radionuclide migration studies we plan to conduct in the Climax granite at the Nevada Test Site. Laboratory support studies are included to help us understand the geochemical and hydrologic processes involved in the field. The Program Plan begins with background information (Section 1) on how this program fits into the National Waste Terminal Storage Program Plan and discusses the needs for field studies of this type. The objectives stated in Section 2 are in direct response to these needs, particularly the need to determine whether laboratory studies accurately reflect actual field conditions and the need for field testing to provide a data base for verification of hydrologic and mass transport models. The technical scope (Section 3) provides a work breakdown structure that integrates the various activities and establishes a base for the technical approach described in Section 4. Our approach combines an interactive system of field and laboratory migration experiments with the use of hydrologic models for pre-test predictions and data interpretation. Section 5 on program interfaces identifies how information will be transferred to other related DOE projects. A schedule of activities and major milestones (Section 6) and the budget necessary to meet the project objectives (Section 7) are included in the Program Plan. Sections 8 and 9 contain brief descriptions of how the technical and program controls will be established and maintained and an outline of our quality assurance program. This program plan is an initial planning document and provides a general description of activities. An Engineering Test Plan containing detailed experimental test plans, an instrumentation plan and equipment design drawings will be published as a separate document

  10. A longitudinal study of plasma insulin and glucagon in women with previous gestational diabetes

    DEFF Research Database (Denmark)

    Damm, P; Kühl, C; Hornnes, P

    1995-01-01

    OBJECTIVE: To investigate whether plasma insulin or glucagon predicts later development of diabetes in women with gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: The subjects studied were 91 women with diet-treated GDM and 33 healthy women. Plasma insulin and glucagon during a 50...... at follow-up (2 had insulin-dependent diabetes mellitus, 13 had non-insulin-dependent diabetes mellitus, and 12 had impaired glucose tolerance). Compared with the control subjects, women with previous GDM had relatively impaired insulin secretion (decreased insulinogenic index and delayed peak insulin...... for subsequent development of overt diabetes (logistic regression analysis). CONCLUSIONS: Women who develop GDM have a relative insulin secretion deficiency, the severity of which is predictive for later development of diabetes. Furthermore, our data indicate that their relatively reduced beta-cell function may...

  11. Zero-field-cooled/field-cooled magnetization study of Dendrimer model

    Energy Technology Data Exchange (ETDEWEB)

    Arejdal, M., E-mail: arejdal.achdad@gmail.com [Laboratory of Magnetism and Physics of High Energies, Department of Physics, L.M.P.H.E (URAC-12), Faculty of Sciences, Mohammed V University, Rabat (Morocco); Bahmad, L. [Laboratory of Magnetism and Physics of High Energies, Department of Physics, L.M.P.H.E (URAC-12), Faculty of Sciences, Mohammed V University, Rabat (Morocco); Benyoussef, A. [Hassan II Academy of Science and Technology, Rabat (Morocco)

    2017-01-01

    Being motivated by Dendrimer model with mixed spins σ=3 and S=7/2, we investigated the magnetic nanoparticle system in this study. We analyzed and discussed the ground-state phase diagrams and the stable phases. Then, we elaborated and explained the magnetic properties of the system by using Monte Carlo Simulations (MCS) in the framework of the Ising model. In this way, we determined the blocking temperature, which is deduced through studying the partial-total magnetization and susceptibility as a function of the temperature, and we established the effects of both the exchange coupling interaction and the crystal field on the hysteresis loop.

  12. Women's decision-making processes and the influences on their mode of birth following a previous caesarean section in Taiwan: a qualitative study.

    Science.gov (United States)

    Chen, Shu-Wen; Hutchinson, Alison M; Nagle, Cate; Bucknall, Tracey K

    2018-01-17

    Vaginal birth after caesarean (VBAC) is an alternative option for women who have had a previous caesarean section (CS); however, uptake is limited because of concern about the risks of uterine rupture. The aim of this study was to explore women's decision-making processes and the influences on their mode of birth following a previous CS. A qualitative approach was used. The research comprised three stages. Stage I consisted of naturalistic observation at 33-34 weeks' gestation. Stage II involved interviews with pregnant women at 35-37 weeks' gestation. Stage III consisted of interviews with the same women who were interviewed postnatally, 1 month after birth. The research was conducted in a private medical centre in northern Taiwan. Using a purposive sampling, 21 women and 9 obstetricians were recruited. Data collection involved in-depth interviews, observation and field notes. Constant comparative analysis was employed for data analysis. Ensuring the safety of mother and baby was the focus of women's decisions. Women's decisions-making influences included previous birth experience, concern about the risks of vaginal birth, evaluation of mode of birth, current pregnancy situation, information resources and health insurance. In communicating with obstetricians, some women complied with obstetricians' recommendations for repeat caesarean section (RCS) without being informed of alternatives. Others used four step decision-making processes that included searching for information, listening to obstetricians' professional judgement, evaluating alternatives, and making a decision regarding mode of birth. After birth, women reflected on their decisions in three aspects: reflection on birth choices; reflection on factors influencing decisions; and reflection on outcomes of decisions. The health and wellbeing of mother and baby were the major concerns for women. In response to the decision-making influences, women's interactions with obstetricians regarding birth choices

  13. Cognition and sensation in very high static magnetic fields: a randomized case-crossover study with different field strengths.

    Science.gov (United States)

    Heinrich, Angela; Szostek, Anne; Meyer, Patric; Nees, Frauke; Rauschenberg, Jaane; Gröbner, Jens; Gilles, Maria; Paslakis, Georgios; Deuschle, Michael; Semmler, Wolfhard; Flor, Herta

    2013-01-01

    To establish the extent to which representative cognitive functions in subjects undergoing magnetic resonance (MR) imaging are acutely impaired by static magnetic fields of varying field strengths. This study was approved by the local ethics committee, and informed consent was obtained from all subjects. In this single-blind case-crossover study, 41 healthy subjects underwent an extensive neuropsychologic examination while in MR units of differing field strengths (1.5, 3.0, and 7.0 T), including a mock imager with no magnetic field as a control condition. Subjects were blinded to field strength. Tests were performed while subjects were lying still in the MR unit and while the examination table was moved. The tests covered a representative set of cognitive functions, such as memory, eye-hand coordination, attention, reaction time, and visual discrimination. Subjective sensory perceptions were also assessed. Effects were analyzed with a repeated-measures analysis of variance; the within-subject factors were field strength (0, 1.5, 3.0, and 7.0 T) and state (static, dynamic). Static magnetic fields were not found to have a significant effect on cognitive function at any field strength. However, sensory perceptions did vary according to field strength. Dizziness, nystagmus, phosphenes, and head ringing were related to the strength of the static magnetic field. Static magnetic fields as high as 7.0 T did not have a significant effect on cognition. RSNA, 2012

  14. Field equations for gravity quadratic in the curvature

    International Nuclear Information System (INIS)

    Rose, B.

    1992-01-01

    Vacuum field equations for gravity are studied having their origin in a Lagrangian quadratic in the curvature. The motivation for this choice of the Lagrangian-namely the treating of gravity in a strict analogy to gauge theories of Yang-Mills type-is criticized, especially the implied view of connections as gauge potentials with no dynamical relation to the metric. The correct field equations with respect to variation of the connections and the metric independently are given. We deduce field equations which differs from previous ones by variation of the metric, the torsion, and the nonmetricity from which the connections are built. 6 refs

  15. Gravitational Field Shielding by Scalar Field and Type II Superconductors

    Directory of Open Access Journals (Sweden)

    Zhang B. J.

    2013-01-01

    Full Text Available The gravitational field shielding by scalar field and type II superconductors are theoret- ically investigated. In accord with the well-developed five-dimensional fully covariant Kaluza-Klein theory with a scalar field, which unifies the Einsteinian general relativity and Maxwellian electromagnetic theory, the scalar field cannot only polarize the space as shown previously, but also flatten the space as indicated recently. The polariza- tion of space decreases the electromagnetic field by increasing the equivalent vacuum permittivity constant, while the flattening of space decreases the gravitational field by decreasing the equivalent gravitational constant. In other words, the scalar field can be also employed to shield the gravitational field. A strong scalar field significantly shield the gravitational field by largely decreasing the equivalent gravitational constant. According to the theory of gravitational field shielding by scalar field, the weight loss experimentally detected for a sample near a rotating ceramic disk at very low tempera- ture can be explained as the shielding of the Earth gravitational field by the Ginzburg- Landau scalar field, which is produced by the type II superconductors. The significant shielding of gravitational field by scalar field produced by superconductors may lead to a new spaceflight technology in future.

  16. Field and laboratory studies provide insights into the meaning of day-time activity in a subterranean rodent (Ctenomys aff. knighti, the tuco-tuco.

    Directory of Open Access Journals (Sweden)

    Barbara M Tomotani

    Full Text Available South American subterranean rodents (Ctenomys aff. knighti, commonly known as tuco-tucos, display nocturnal, wheel-running behavior under light-dark (LD conditions, and free-running periods >24 h in constant darkness (DD. However, several reports in the field suggested that a substantial amount of activity occurs during daylight hours, leading us to question whether circadian entrainment in the laboratory accurately reflects behavior in natural conditions. We compared circadian patterns of locomotor activity in DD of animals previously entrained to full laboratory LD cycles (LD12:12 with those of animals that were trapped directly from the field. In both cases, activity onsets in DD immediately reflected the previous dark onset or sundown. Furthermore, freerunning periods upon release into DD were close to 24 h indicating aftereffects of prior entrainment, similarly in both conditions. No difference was detected in the phase of activity measured with and without access to a running wheel. However, when individuals were observed continuously during daylight hours in a semi-natural enclosure, they emerged above-ground on a daily basis. These day-time activities consisted of foraging and burrow maintenance, suggesting that the designation of this species as nocturnal might be inaccurate in the field. Our study of a solitary subterranean species suggests that the circadian clock is entrained similarly under field and laboratory conditions and that day-time activity expressed only in the field is required for foraging and may not be time-dictated by the circadian pacemaker.

  17. The influence of catch trials on the consolidation of motor memory in force field adaptation tasks

    Directory of Open Access Journals (Sweden)

    Anne eFocke

    2013-07-01

    Full Text Available In computational neuroscience it is generally accepted that human motor memory contains neural representations of the physics of the musculoskeletal system and the objects in the environment. These representations are called internal models. Force field studies, in which subjects have to adapt to dynamic perturbations induced by a robotic manipulandum, are an established tool to analyze the characteristics of such internal models. The aim of the current study was to investigate whether catch trials during force field learning could influence the consolidation of motor memory in more complex tasks. Thereby, the force field was more than double the force field of previous studies (35 Ns/m. Moreover, the arm of the subjects was not supported. A total of forty-six subjects participated in this study and performed center-out movements at a robotic manipulandum in two different force fields. Two control groups learned force field A on day 1 and were retested in the same force field on day 3 (AA. Two test groups additionally learned an interfering force field B (=-A on day 2 (ABA. The difference between the two test and control groups, respectively, was the absence (0% or presence (19% of catch trials, in which the force field was turned off suddenly. The results showed consolidation of force field A on day 3 for both control groups. Test groups showed no consolidation of force field A (19% catch trials and even poorer performance on day 3 (0% catch trials. In conclusion, it can be stated that catch trials seem to have a positive effect on the performance on day 3 but do not trigger a consolidation process as shown in previous studies that used a lower force field viscosity with supported arm. These findings indicate that the results of previous studies in which less complex tasks were analyzed, cannot be fully transferred to more complex tasks. Moreover, the effects of catch trials in these situations are insufficiently understood and further research

  18. A study about the interest and previous contact of high school students with Astronomy

    Science.gov (United States)

    Carvalho, C. L.; Zanitti, M. H. R.; Felicidade, B. L.; Gomes, A. D. T.; Dias, E. W.; Coelho, F. O.

    2016-04-01

    The currently problems in Astronomy teaching in Brazilian Basic Education contrast with the space, and the popularity that astronomical themes have in various media in the country. In this work, we present the results of a study about the interest, and previous contact of high school students from a public school in the city of "São João del-Rei"/MG with topics related to Astronomy. The study and the pedagogical intervention were carried out by students of the PIBID/CAPES/UFSJ. The intervention was performed through an oral exposition with the students' participation, followed by the use of the Stellarium program. The results suggest the majority of students surveyed are interested in Astronomy, and have had some contact with the area. However, some inconsistencies in their responses were identified and examined. The implications for research and for Astronomy Education are discussed. We also make some considerations about relationship between the lack of specific knowledge and the misinformation as one possible reason for the little interest of students in various areas of Science.

  19. Ionization and recombination in attosecond electric field pulses

    International Nuclear Information System (INIS)

    Dimitrovski, Darko; Solov'ev, Eugene A.; Briggs, John S.

    2005-01-01

    Based on the results of a previous communication [Dimitrovski et al., Phys. Rev. Lett. 93, 083003 (2004)], we study ionization and excitation of a hydrogenic atom from the ground and first excited states in short electric field pulses of several cycles. A process of ionization and recombination which occurs periodically in time is identified, for both small and extremely large peak electric field strengths. In the limit of large electric peak fields closed-form analytic expressions for the population of the initial state after single- and few-cycle pulses are derived. These formulas, strictly valid for asymptotically large momentum transfer from the field, give excellent agreement with fully numerical calculations for all momentum transfers

  20. Evaporation Rate of Water as a Function of a Magnetic Field and Field Gradient

    Directory of Open Access Journals (Sweden)

    Peng Shang

    2012-12-01

    Full Text Available The effect of magnetic fields on water is still a highly controversial topic despite the vast amount of research devoted to this topic in past decades. Enhanced water evaporation in a magnetic field, however, is less disputed. The underlying mechanism for this phenomenon has been investigated in previous studies. In this paper, we present an investigation of the evaporation of water in a large gradient magnetic field. The evaporation of pure water at simulated gravity positions (0 gravity level (ab. g, 1 g, 1.56 g and 1.96 g in a superconducting magnet was compared with that in the absence of the magnetic field. The results showed that the evaporation of water was indeed faster in the magnetic field than in the absence of the magnetic field. Furthermore, the amount of water evaporation differed depending on the position of the sample within the magnetic field. In particular, the evaporation at 0 g was clearly faster than that at other positions. The results are discussed from the point of view of the evaporation surface area of the water/air interface and the convection induced by the magnetization force due to the difference in the magnetic susceptibility of water vapor and the surrounding air.

  1. Evaporation rate of water as a function of a magnetic field and field gradient.

    Science.gov (United States)

    Guo, Yun-Zhu; Yin, Da-Chuan; Cao, Hui-Ling; Shi, Jian-Yu; Zhang, Chen-Yan; Liu, Yong-Ming; Huang, Huan-Huan; Liu, Yue; Wang, Yan; Guo, Wei-Hong; Qian, Ai-Rong; Shang, Peng

    2012-12-11

    The effect of magnetic fields on water is still a highly controversial topic despite the vast amount of research devoted to this topic in past decades. Enhanced water evaporation in a magnetic field, however, is less disputed. The underlying mechanism for this phenomenon has been investigated in previous studies. In this paper, we present an investigation of the evaporation of water in a large gradient magnetic field. The evaporation of pure water at simulated gravity positions (0 gravity level (ab. g), 1 g, 1.56 g and 1.96 g) in a superconducting magnet was compared with that in the absence of the magnetic field. The results showed that the evaporation of water was indeed faster in the magnetic field than in the absence of the magnetic field. Furthermore, the amount of water evaporation differed depending on the position of the sample within the magnetic field. In particular, the evaporation at 0 g was clearly faster than that at other positions. The results are discussed from the point of view of the evaporation surface area of the water/air interface and the convection induced by the magnetization force due to the difference in the magnetic susceptibility of water vapor and the surrounding air.

  2. Evaporation Rate of Water as a Function of a Magnetic Field and Field Gradient

    Science.gov (United States)

    Guo, Yun-Zhu; Yin, Da-Chuan; Cao, Hui-Ling; Shi, Jian-Yu; Zhang, Chen-Yan; Liu, Yong-Ming; Huang, Huan-Huan; Liu, Yue; Wang, Yan; Guo, Wei-Hong; Qian, Ai-Rong; Shang, Peng

    2012-01-01

    The effect of magnetic fields on water is still a highly controversial topic despite the vast amount of research devoted to this topic in past decades. Enhanced water evaporation in a magnetic field, however, is less disputed. The underlying mechanism for this phenomenon has been investigated in previous studies. In this paper, we present an investigation of the evaporation of water in a large gradient magnetic field. The evaporation of pure water at simulated gravity positions (0 gravity level (ab. g), 1 g, 1.56 g and 1.96 g) in a superconducting magnet was compared with that in the absence of the magnetic field. The results showed that the evaporation of water was indeed faster in the magnetic field than in the absence of the magnetic field. Furthermore, the amount of water evaporation differed depending on the position of the sample within the magnetic field. In particular, the evaporation at 0 g was clearly faster than that at other positions. The results are discussed from the point of view of the evaporation surface area of the water/air interface and the convection induced by the magnetization force due to the difference in the magnetic susceptibility of water vapor and the surrounding air. PMID:23443127

  3. Ifosfamide in previously untreated disseminated neuroblastoma. Results of Study 3A of the European Neuroblastoma Study Group.

    Science.gov (United States)

    Kellie, S J; De Kraker, J; Lilleyman, J S; Bowman, A; Pritchard, J

    1988-05-01

    A prospective study of the effectiveness of ifosfamide as a single agent in the management of previously untreated patients with Evans stage IV neuroblastoma was undertaken. Eighteen children aged more than 1 year were treated with ifosfamide (IFX) 3 g/m2 daily for 2 days immediately after diagnosis and 3 weeks later. Treatment was continued with combination chemotherapy using vincristine, cyclophosphamide, cisplatinum and etoposide (OPEC) or a variant. Mesna (2-mercaptoethane sulphonate) was given to all patients during IFX treatment to prevent urotoxicity. Eight of the 18 patients (44%) responded to IFX. Nine had greater than 66% reduction in baseline tumor volume. Of 15 evaluable patients with raised pre-treatment urinary catecholamine excretion, six (40%) achieved greater than 50% reduction in pretreatment levels. Two of 10 patients evaluable for bone marrow response had complete clearance. Toxicity was mild in all patients. Upon completing 'first line' therapy, only four patients (22%) achieved a good partial remission (GPR) or complete response (CR). Median survival was 11 months. There was a lower rate of attaining GPR and shortened median survival in patients receiving phase II IFX before OPEC or variant, compared to patients with similar pre-treatment characteristics treated with OPEC from diagnosis in an earlier study.

  4. Competencies of Track and Field coaches. An Exploratory Study

    Directory of Open Access Journals (Sweden)

    Alexandra Tripolitsioti

    2012-01-01

    Full Text Available The aim of this study was to construct a questionnaire to identify the knowledge and skills needed by track and field coaches in Greece to perform their role. Following standard procedures, an instrument with 42 items was constructed. Three hundred and forty nine Greek track and field coaches, who have been working 15+-2.8 y in the first and second division, aged 45+-4.4 y, participated in the study and rated the items of the questionnaire according to a Likert scale. Exploratory factor analysis revealed five factors comprising 22 competency statements: a field management techniques (7 items, b sport science (5 items, c injury prevention/crisis management (3 items; d biology (3 items; and e field training (4 items. The internal validity revealed a Cronbach’s alpha factor of 0.894 with subscales ranging from 0.657 to 0.886. Results also showed that demonstrating an understanding of specific inherent risks of sport activity and an understanding of psychology were the top rated competencies, while preparing a budget proposal and utilizing effective office procedures to handle registrations, reports, notices, etc., were the lower rated competencies. It is concluded that the questionnaire developed in this study is a reliable and valid instrument to measure the competencies of track and field coaches in Greece.

  5. Measurements of crossed-field demagnetisation rate of trapped field magnets at high frequencies and below 77 K

    Science.gov (United States)

    Baskys, A.; Patel, A.; Glowacki, B. A.

    2018-06-01

    Design requirements of the next generation of electric aircraft place stringent requirements on the power density required from electric motors. A future prototype planned in the scope of the European project ‘Advanced Superconducting Motor Experimental Demonstrator’ (ASuMED) considers a permanent magnet synchronous motor, where the conventional ferromagnets are replaced with superconducting trapped field magnets, which promise higher flux densities and thus higher output power without adding weight. Previous work has indicated that stacks of tape show lower cross-field demagnetisation rates to bulk (RE)BCO whilst retaining similar performance for their size, however the crossed-field demagnetisation rate has not been studied in the temperature, the magnetic field and frequency range that are relevant for the operational prototype motor. This work investigates crossed-field demagnetisation in 2G high temperature superconducting stacks at temperatures below 77 K and a frequency range above 10 Hz. This information is crucial in developing designs and determining operational time before re-magnetisation could be required.

  6. Polynomial pseudosupersymmetry underlying a two-level atom in an external electromagnetic field

    International Nuclear Information System (INIS)

    Samsonov, B.F.; Shamshutdinova, V.V.; Gitman, D.M.

    2005-01-01

    Chains of transformations introduced previously were studied in order to obtain electric fields with a time-dependent frequency for which the equation of motion of a two-level atom in the presence of these fields can be solved exactly. It is shown that a polynomial pseudosupersymmetry may be associated to such chains

  7. Theoretical study of structure of electric field in helical toroidal plasmas

    International Nuclear Information System (INIS)

    Toda, S.; Itoh, K.

    2001-06-01

    A set of transport equations is analyzed, including the bifurcation of the electric field. The structure of the electric field is studied by use of the theoretical model for the anomalous transport diffusivities. The steep gradient of the electric field is obtained at the electric domain. The suppression of the anomalous transport diffusivity is studied in the presence of the strong shear of the electric field. The hard transition with the multiple ambipolar solutions is examined in the structure of the radial electric field. The details of the structure of the electric domain interface are investigated. (author)

  8. Isotope study in geothermal fields in Java Island

    International Nuclear Information System (INIS)

    Wandowo, Z.A.

    1995-01-01

    Study in two geothermal fields, Dieng and Kamojang, in Java island by utilizing isotope technique has been carried out. Isotopic data of wells, springs and other geothermal manifestations providing informations on the recharge area of precipitation contributed to geothermal resources, flow paths and origin of geothermal fluids. The data of oxygen shift has also provided information on the characteristic the fields. (author). 8 refs, 5 figs, 3 tabs

  9. Mössbauer studies of hyperfine fields in disordered Fe CrAl

    Indian Academy of Sciences (India)

    magnetic hyperfine field, the average hyperfine field follows the ´T Tcµ3 2 law. The paramagnetic part of the hyperfine field is explained in terms of the clustering of Cr ... These alloys offer excellent systems for studying magnetic interactions. Large volumes of studies have been devoted to Heusler alloys bearing the general ...

  10. Youth suicide: an insight into previous hospitalisation for injury and sociodemographic conditions from a nationwide cohort study.

    Science.gov (United States)

    Zambon, Francesco; Laflamme, Lucie; Spolaore, Paolo; Visentin, Cristiana; Hasselberg, Marie

    2011-06-01

    This study investigates the degree to which a previous hospitalisation for injury of any intent is a risk of subsequent youth suicide and whether this association is influenced by family socioeconomic status or economic stress. A nationwide register-based cohort study was conducted covering all Swedish subjects born between January 1977 and December 1991 (N=1,616,342, male/female ratio=1.05). The cohort subjects were followed-up from January 1998 to December 2003, when aged 7-26 years. Poisson regression and the likelihood ratio test (95% CI) were used to assess the age-adjusted effect of hospitalisation for injuries of various intent on youth suicide and its effect once adjusted for family sociodemographic and social circumstances. Each set of exposures was associated independently and significantly with suicide mortality. Being hospitalised for self-inflicted injuries or injuries of undetermined intent was associated with a risk of suicide 36 to 47 times, respectively, that of subjects never hospitalised in the period under study (95% CI 28.36 to 45.58 and 26.67 to 83.87 for self-inflicted injuries and for events of undetermined intent, respectively; overall psuicide (RR 3.08; 95% CI 2.26 to 4.19). These effects were solid and not substantially altered after adjustment for family demographic and socioeconomic circumstances. A strong association exists between previous hospitalisation for injury of any intent and youth suicide. The association is robust and unaltered by family socioeconomic circumstances.

  11. Outcome of trial of scar in patients with previous caesarean section

    International Nuclear Information System (INIS)

    Khan, B.; Bashir, R.; Khan, W.

    2016-01-01

    Medical evidence indicates that 60-80% of women can achieve vaginal delivery after a previous lower segment caesarean section. Proper selection of patients for trial of scar and vigilant monitoring during labour will achieve successful maternal and perinatal outcome. The objective of our study is to establish the fact that vaginal delivery after one caesarean section has a high success rate in patients with previous one caesarean section for non-recurrent cause. Methods: The study was conducted in Ayub Teaching Abbottabad, Gynae-B Unit. All labouring patients, during the study period of five years, with previous one caesarean section and between 37 weeks to 41 weeks of gestation for a non-recurrent cause were included in the study. Data was recorded on special proforma designed for the purpose. Patients who had previous classical caesarean section, more than one caesarean section, and previous caesarean section with severe wound infection, transverse lie and placenta previa in present pregnancy were excluded. Foetal macrosomia (wt>4 kg) and severe IUGR with compromised blood flow on Doppler in present pregnancy were also not considered suitable for the study. Patients who had any absolute contraindication for vaginal delivery were also excluded. Results: There were 12505 deliveries during the study period. Total vaginal deliveries were 8790 and total caesarean sections were 3715. Caesarean section rate was 29.7%. Out of these 8790 patients, 764 patients were given a trial of scar and 535 patients delivered successfully vaginally (70%). Women who presented with spontaneous onset of labour were more likely to deliver vaginally (74.8%) as compared to induction group (27.1%). Conclusion: Trial of vaginal birth after caesarean (VBAC) in selected cases has great importance in the present era of the rising rate of primary caesarean section. (author)

  12. Sudden unexpected death in children with a previously diagnosed cardiovascular disorder

    NARCIS (Netherlands)

    Polderman, Florens N.; Cohen, Joeri; Blom, Nico A.; Delhaas, Tammo; Helbing, Wim A.; Lam, Jan; Sobotka-Plojhar, Marta A.; Temmerman, Arno M.; Sreeram, Narayanswani

    2004-01-01

    BACKGROUND: It is known that children with previously diagnosed heart defects die suddenly. The causes of death are often unknown. OBJECTIVE: The aim of the study was to identify all infants and children within the Netherlands with previously diagnosed heart disease who had a sudden unexpected death

  13. Sudden unexpected death in children with a previously diagnosed cardiovascular disorder

    NARCIS (Netherlands)

    Polderman, F.N.; Cohen, Joeri; Blom, N.A.; Delhaas, T.; Helbing, W.A.; Lam, J.; Sobotka-Plojhar, M.A.; Temmerman, Arno M.; Sreeram, N.

    2004-01-01

    Background: It is known that children with previously diagnosed heart defects die suddenly. The causes of death are often unknown. Objective: The aim of the study was to identify all infants and children within the Netherlands with previously diagnosed heart disease who had a sudden unexpected death

  14. Development of a source-exposure matrix for occupational exposure assessment of electromagnetic fields in the INTEROCC study.

    Science.gov (United States)

    Vila, Javier; Bowman, Joseph D; Figuerola, Jordi; Moriña, David; Kincl, Laurel; Richardson, Lesley; Cardis, Elisabeth

    2017-07-01

    To estimate occupational exposures to electromagnetic fields (EMF) for the INTEROCC study, a database of source-based measurements extracted from published and unpublished literature resources had been previously constructed. The aim of the current work was to summarize these measurements into a source-exposure matrix (SEM), accounting for their quality and relevance. A novel methodology for combining available measurements was developed, based on order statistics and log-normal distribution characteristics. Arithmetic and geometric means, and estimates of variability and maximum exposure were calculated by EMF source, frequency band and dosimetry type. The mean estimates were weighted by our confidence in the pooled measurements. The SEM contains confidence-weighted mean and maximum estimates for 312 EMF exposure sources (from 0 Hz to 300 GHz). Operator position geometric mean electric field levels for radiofrequency (RF) sources ranged between 0.8 V/m (plasma etcher) and 320 V/m (RF sealer), while magnetic fields ranged from 0.02 A/m (speed radar) to 0.6 A/m (microwave heating). For extremely low frequency sources, electric fields ranged between 0.2 V/m (electric forklift) and 11,700 V/m (high-voltage transmission line-hotsticks), whereas magnetic fields ranged between 0.14 μT (visual display terminals) and 17 μT (tungsten inert gas welding). The methodology developed allowed the construction of the first EMF-SEM and may be used to summarize similar exposure data for other physical or chemical agents.

  15. Diffusive processes in a stochastic magnetic field

    International Nuclear Information System (INIS)

    Wang, H.; Vlad, M.; Vanden Eijnden, E.; Spineanu, F.; Misguich, J.H.; Balescu, R.

    1995-01-01

    The statistical representation of a fluctuating (stochastic) magnetic field configuration is studied in detail. The Eulerian correlation functions of the magnetic field are determined, taking into account all geometrical constraints: these objects form a nondiagonal matrix. The Lagrangian correlations, within the reasonable Corrsin approximation, are reduced to a single scalar function, determined by an integral equation. The mean square perpendicular deviation of a geometrical point moving along a perturbed field line is determined by a nonlinear second-order differential equation. The separation of neighboring field lines in a stochastic magnetic field is studied. We find exponentiation lengths of both signs describing, in particular, a decay (on the average) of any initial anisotropy. The vanishing sum of these exponentiation lengths ensures the existence of an invariant which was overlooked in previous works. Next, the separation of a particle's trajectory from the magnetic field line to which it was initially attached is studied by a similar method. Here too an initial phase of exponential separation appears. Assuming the existence of a final diffusive phase, anomalous diffusion coefficients are found for both weakly and strongly collisional limits. The latter is identical to the well known Rechester-Rosenbluth coefficient, which is obtained here by a more quantitative (though not entirely deductive) treatment than in earlier works

  16. Teaching and Learning in the Tropics: An Epistemic Exploration of "the Field" in a Development Studies Field Trip

    Science.gov (United States)

    Patel, Kamna

    2015-01-01

    Development studies employs theories, tools and methods often found in geography, including the international field trip to a "developing" country. In 2013 and 2014, I led a two-week trip to Ethiopia. To better comprehend the effects of "the field" on students' learning, I introduced an assessed reflexive field diary to…

  17. Separation of large DNA molecules by applying pulsed electric field to size exclusion chromatography-based microchip

    Science.gov (United States)

    Azuma, Naoki; Itoh, Shintaro; Fukuzawa, Kenji; Zhang, Hedong

    2018-02-01

    Through electrophoresis driven by a pulsed electric field, we succeeded in separating large DNA molecules with an electrophoretic microchip based on size exclusion chromatography (SEC), which was proposed in our previous study. The conditions of the pulsed electric field required to achieve the separation were determined by numerical analyses using our originally proposed separation model. From the numerical results, we succeeded in separating large DNA molecules (λ DNA and T4 DNA) within 1600 s, which was approximately half of that achieved under a direct electric field in our previous study. Our SEC-based electrophoresis microchip will be one of the effective tools to meet the growing demand of faster and more convenient separation of large DNA molecules, especially in the field of epidemiological research of infectious diseases.

  18. Satellite to study earth's magnetic field

    Science.gov (United States)

    1979-01-01

    The Magnetic Field Satellite (Magsat) designed to measure the near earth magnetic field and crustal anomalies is briefly described. A scalar magnetometer to measure the magnitude of the earth's crustal magnetic field and a vector magnetometer to measure magnetic field direction as well as magnitude are included. The mission and its objectives are summarized along with the data collection and processing system.

  19. 1992-93 Results of geomorphological and field studies Volcanic Studies Program, Yucca Mountain Project

    International Nuclear Information System (INIS)

    Wells, S.G.

    1993-10-01

    Field mapping and stratigraphic studies were completed of the Black Tank volcanic center, which represents the southwestern most eruptive center in the Cima volcanic field of California. The results of this mapping are presented. Contacts between volcanic units and geomorphic features were field checked, incorporating data from eight field trenches as well as several exposures along Black Tank Wash. Within each of the eight trenches, logs were measured and stratigraphic sections were described. These data indicate that three, temporally separate volcanic eruptions occurred at the Black Tank center. The field evidence for significant time breaks between each stratigraphic unit is the presence of soil and pavement-bounded unconformities

  20. Study of detectors in beta radiation fields

    International Nuclear Information System (INIS)

    Albuquerque, M. da P.P.; Xavier, M.; Caldas, L.V.E.

    1987-01-01

    Several commercial detectors used with gamma or X radiation are studied. Their sensibility and energetic dependence are analysed in exposures of beta radiation fields. A comparative evaluation with the reference detector (the extrapolation chamber) is presented. (M.A.C.) [pt

  1. 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

  2. Everolimus for Previously Treated Advanced Gastric Cancer: Results of the Randomized, Double-Blind, Phase III GRANITE-1 Study

    Science.gov (United States)

    Ohtsu, Atsushi; Ajani, Jaffer A.; Bai, Yu-Xian; Bang, Yung-Jue; Chung, Hyun-Cheol; Pan, Hong-Ming; Sahmoud, Tarek; Shen, Lin; Yeh, Kun-Huei; Chin, Keisho; Muro, Kei; Kim, Yeul Hong; Ferry, David; Tebbutt, Niall C.; Al-Batran, Salah-Eddin; Smith, Heind; Costantini, Chiara; Rizvi, Syed; Lebwohl, David; Van Cutsem, Eric

    2013-01-01

    Purpose The oral mammalian target of rapamycin inhibitor everolimus demonstrated promising efficacy in a phase II study of pretreated advanced gastric cancer. This international, double-blind, phase III study compared everolimus efficacy and safety with that of best supportive care (BSC) in previously treated advanced gastric cancer. Patients and Methods Patients with advanced gastric cancer that progressed after one or two lines of systemic chemotherapy were randomly assigned to everolimus 10 mg/d (assignment schedule: 2:1) or matching placebo, both given with BSC. Randomization was stratified by previous chemotherapy lines (one v two) and region (Asia v rest of the world [ROW]). Treatment continued until disease progression or intolerable toxicity. Primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), overall response rate, and safety. Results Six hundred fifty-six patients (median age, 62.0 years; 73.6% male) were enrolled. Median OS was 5.4 months with everolimus and 4.3 months with placebo (hazard ratio, 0.90; 95% CI, 0.75 to 1.08; P = .124). Median PFS was 1.7 months and 1.4 months in the everolimus and placebo arms, respectively (hazard ratio, 0.66; 95% CI, 0.56 to 0.78). Common grade 3/4 adverse events included anemia, decreased appetite, and fatigue. The safety profile was similar in patients enrolled in Asia versus ROW. Conclusion Compared with BSC, everolimus did not significantly improve overall survival for advanced gastric cancer that progressed after one or two lines of previous systemic chemotherapy. The safety profile observed for everolimus was consistent with that observed for everolimus in other cancers. PMID:24043745

  3. The numerical solution of ICRF fields in axisymmetric mirrors

    International Nuclear Information System (INIS)

    Phillips, M.W.; Todd, A.M.M.

    1986-01-01

    The numerics of a numerical code called GARFIELD (Grumman Aerospace RF fIELD code) designed to calculate the three-dimensional structure of ICRF fields in axisymmetric mirrors is presented. The code solves the electromagnetic wave equation for the electric field using a cold plasma dispersion relation with a small collision term to simulate absorption. The full wave solution including E.B is computed. The fields are Fourier analyzed in the poloidal direction and solved on a grid in the axial and radial directions. A two-dimensional equilibrium can be used as the source of equilibrium data. This allows us to extend previous studies of ICRF wave propagation and absorption in mirrors to include the effect of axial variation of the magnetic field and density. (orig.)

  4. Response to health insurance by previously uninsured rural children.

    Science.gov (United States)

    Tilford, J M; Robbins, J M; Shema, S J; Farmer, F L

    1999-08-01

    To examine the healthcare utilization and costs of previously uninsured rural children. Four years of claims data from a school-based health insurance program located in the Mississippi Delta. All children who were not Medicaid-eligible or were uninsured, were eligible for limited benefits under the program. The 1987 National Medical Expenditure Survey (NMES) was used to compare utilization of services. The study represents a natural experiment in the provision of insurance benefits to a previously uninsured population. Premiums for the claims cost were set with little or no information on expected use of services. Claims from the insurer were used to form a panel data set. Mixed model logistic and linear regressions were estimated to determine the response to insurance for several categories of health services. The use of services increased over time and approached the level of utilization in the NMES. Conditional medical expenditures also increased over time. Actuarial estimates of claims cost greatly exceeded actual claims cost. The provision of a limited medical, dental, and optical benefit package cost approximately $20-$24 per member per month in claims paid. An important uncertainty in providing health insurance to previously uninsured populations is whether a pent-up demand exists for health services. Evidence of a pent-up demand for medical services was not supported in this study of rural school-age children. States considering partnerships with private insurers to implement the State Children's Health Insurance Program could lower premium costs by assembling basic data on previously uninsured children.

  5. Early results from Magsat. [studies of near-earth magnetic fields

    Science.gov (United States)

    Langel, R. A.; Estes, R. H.; Mayhew, M. A.

    1981-01-01

    Papers presented at the May 27, 1981 meeting of the American Geophysical Union concerning early results from the Magsat satellite program, which was designed to study the near-earth magnetic fields originating in the core and lithosphere, are discussed. The satellite was launched on October 30, 1979 into a sun-synchronous (twilight) orbit, and re-entered the atmosphere on June 11, 1980. Instruments carried included a cesium vapor magnetometer to measure field magnitudes, a fluxgate magnetometer to measure field components and an optical system to measure fluxgate magnetometer orientation. Early results concerned spherical harmonic models, fields due to ionospheric and magnetospheric currents, the identification and interpretation of fields from lithospheric sources. The preliminary results confirm the possibility of separating the measured field into core, crustal and external components, and represent significant developments in analytical techniques in main-field modelling and the physics of the field sources.

  6. Multi-frequency ESR studies on a Haldane magnet in a field-induced phase at ultra-low temperatures

    International Nuclear Information System (INIS)

    Hagiwara, Masayuki; Kashiwagi, Takanari; Idutsu, Yuichi; Honda, Zentaro; Miyazaki, Hiroshi; Harada, Isao

    2010-01-01

    We report the results of multi-frequency electron spin resonance (ESR) measurements on single crystals of Ni(C 5 H 14 N 2 ) 2 N 3 (PF 6 ) which is regarded as the one-dimensional Heisenberg antiferromagnet with spin one, namely the Haldane magnet, at very low temperatures down to about 100 mK. We observed the lowest resonance branch below about 500 mK for the field along the chain direction (H||c), which was observed previously only in an inelastic neutron scattering experiment at 30 mK. We compare the resonance branch with that calculated by a phenomenological field theory, and discuss the field dependence and the temperature sensitivity of this ESR branch.

  7. Field-of-study mismatch and overqualification: labour market correlates and their wage penalty

    Directory of Open Access Journals (Sweden)

    Guillermo Montt

    2017-01-01

    Full Text Available Abstract Field-of-study mismatch occurs when a worker, trained in a particular field, works in another field. This study draws on the Survey of Adult Skills (PIAAC to explore how skill supply and labour market demand dynamics influence mismatch. It updates cross-national estimates on mismatch and estimates the mismatch wage penalty. Findings suggest that around 40% of workers are mismatched by field at their qualification level, 11% overqualified in their field and 13% overqualified and working outside their field. The saturation of the field in the labour market and the transferability of the fields’ skills predict the incidence of field-of-study mismatch and overqualification. Workers who are mismatched by field only suffer a wage penalty if they are overqualified.

  8. Ab-initio study of the relation between electric polarization and electric field gradients in ferroelectrics

    CERN Document Server

    Gonçalves, J N; Correia, J G; Butz, T; Picozzi, S; Fenta, A S; Amaral, V S

    2012-01-01

    The hyperfine interaction between the quadrupole moment of atomic nuclei and the electric field gradient (EFG) provides information on the electronic charge distribution close to a given atomic site. In ferroelectric materials, the loss of inversion symmetry of the electronic charge distribution is necessary for the appearance of the electric polarization. We present first-principles density functional theory calculations of ferroelectrics such as BaTiO$_{3}$, KNbO$_{3}$, PbTiO$_{3}$ and other oxides with perovskite structures, by focusing on both EFG tensors and polarization. We analyze the EFG tensor properties such as orientation and correlation between components and their relation with electric polarization. This work supports previous studies of ferroelectric materials where a relation between EFG tensors and polarization was observed, which may be exploited to study the ferroelectric order when standard techniques to measure polarization are not easily applied.

  9. Influence of magnetic field configuration on magnetohydrodynamic waves in Earth's core

    Science.gov (United States)

    Knezek, Nicholas; Buffett, Bruce

    2018-04-01

    We develop a numerical model to study magnetohydrodynamic waves in a thin layer of stratified fluid near the surface of Earth's core. Past studies have been limited to using simple background magnetic field configurations. However, the choice of field distribution can dramatically affect the structure and frequency of the waves. To permit a more general treatment of background magnetic field and layer stratification, we combine finite volume and Fourier methods to describe the wave motions. We validate our model by comparisons to previous studies and examine the influence of background magnetic field configuration on two types of magnetohydrodynamic waves. We show that the structure of zonal Magnetic-Archimedes-Coriolis (MAC) waves for a dipole background field is unstable to small perturbations of the field strength in the equatorial region. Modifications to the wave structures are computed for a range of field configurations. In addition, we show that non-zonal MAC waves are trapped near the equator for realistic magnetic field distributions, and that their latitudinal extent depends upon the distribution of magnetic field strength at the CMB.

  10. International Geomagnetic Reference Field

    DEFF Research Database (Denmark)

    Finlay, Chris; Maus, S.; Beggan, C. D.

    2010-01-01

    The eleventh generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2009 by the International Association of Geomagnetism and Aeronomy Working Group V‐MOD. It updates the previous IGRF generation with a definitive main field model for epoch 2005.0, a main field...... model for epoch 2010.0, and a linear predictive secular variation model for 2010.0–2015.0. In this note the equations defining the IGRF model are provided along with the spherical harmonic coefficients for the eleventh generation. Maps of the magnetic declination, inclination and total intensity...

  11. Gravity field modeling at the sea areas using satellite altimetry observations Case study: Gravity field modeling at the Coastal Fars

    International Nuclear Information System (INIS)

    Jomegi, A.

    2007-01-01

    Nowadays, satellite altimetry observations had made it possible to determine sea surface variations, in the global scale, to high degree of precision. Using satellite altimetry observations, Mean Sea Level (MSL) can be determined, which by Kowing Sea Surface Topography (SST), can be converted into high-resolution marine geoid. In this paper we are proposing a method for computation of the Earth's gravity field at the sea areas, which is different from usual methods. Indeed, our method is based on conversion of geoidal heights into gravity potential values at the reference ellipsoid 2 Ea,b , by using ellipsoidal Brun's formula, and forward application of solution of Fixed-Free Two Boundary Value Problem (FFTBVP), previously proposed by the authors for the geoid computations without application of Stokes formula. Numerical results of application of the proposed method at the test area of CoastalFars (at southern part of Iran) show the success of the method. Considering the low cost and high precision of satellite altimetry observations, the proposed method suggests an efficient substitution to shipborne gravity observations for gravity field molding at the sea areas

  12. Cellular studies and interaction mechanisms of extremely low frequency fields

    Science.gov (United States)

    Liburdy, Robert P.

    1995-01-01

    Worldwide interest in the biological effects of ELF (extremely low frequency, level is to identify cellular responses to ELF fields, to develop a dose threshold for such interactions, and with such information to formulate and test appropriate interaction mechanisms. This review is selective and will discuss the most recent cellular studies directed at these goals which relate to power line, sinusoidal ELF fields. In these studies an interaction site at the cell membrane is by consensus a likely candidate, since changes in ion transport, ligand-receptor events such as antibody binding, and G protein activation have been reported. These changes strongly indicate that signal transduction (ST) can be influenced. Also, ELF fields are reported to influence enzyme activation, gene expression, protein synthesis, and cell proliferation, which are triggered by earlier ST events at the cell membrane. The concept of ELF fields altering early cell membrane events and thereby influencing intracellular cell function via the ST cascade is perhaps the most plausible biological framework currently being investigated for understanding ELF effects on cells. For example, the consequence of an increase due to ELF fields in mitogenesis, the final endpoint of the ST cascade, is an overall increase in the probability of mutagenesis and consequently cancer, according to the Ames epigenetic model of carcinogenesis. Consistent with this epigenetic mechanism and the ST pathway to carcinogenesis is recent evidence that ELF fields can alter breast cancer cell proliferation and can act as a copromoter in vitro. The most important dosimetric question being addressed currently is whether the electric (E) or the magnetic (B) field, or if combinations of static B and time-varying B fields represent an exposure metric for the cell. This question relates directly to understanding fundamental interaction mechanisms and to the development of a rationale for ELF dose threshold guidelines. The weight of

  13. Intense field stabilization in circular polarization: Three-dimensional time-dependent dynamics

    International Nuclear Information System (INIS)

    Choi, Dae-Il; Chism, Will

    2002-01-01

    We investigate the stabilization of hydrogen atoms in a circularly polarized laser field. We use a three-dimensional, time-dependent approach to study the quantum dynamics of hydrogen atoms subject to high-intensity, short-wavelength, laser pulses. We find an enhanced survival probability as the field is increased under fixed envelope conditions. We also confirm wave packet behaviors previously seen in two-dimensional time-dependent computations

  14. Vadose Zone Transport Field Study: Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Andy L.; Conrad, Mark E.; Daily, William D.; Fink, James B.; Freedman, Vicky L.; Gee, Glendon W.; Hoversten, Gary M.; Keller, Jason M.; Majer, Ernest L.; Murray, Christopher J.; White, Mark D.; Yabusaki, Steven B.; Zhang, Z. F.

    2006-07-31

    From FY 2000 through FY 2003, a series of vadose zone transport field experiments were conducted as part of the U.S. Department of Energy’s Groundwater/Vadose Zone Integration Project Science and Technology Project, now known as the Remediation and Closure Science Project, and managed by the Pacific Northwest National Laboratory (PNNL). The series of experiments included two major field campaigns, one at a 299-E24-11 injection test site near PUREX and a second at a clastic dike site off Army Loop Road. The goals of these experiments were to improve our understanding of vadose zone transport processes; to develop data sets to validate and calibrate vadose zone flow and transport models; and to identify advanced monitoring techniques useful for evaluating flow-and-transport mechanisms and delineating contaminant plumes in the vadose zone at the Hanford Site. This report summarizes the key findings from the field studies and demonstrates how data collected from these studies are being used to improve conceptual models and develop numerical models of flow and transport in Hanford’s vadose zone. Results of these tests have led to a better understanding of the vadose zone. Fine-scale geologic heterogeneities, including grain fabric and lamination, were observed to have a strong effect on the large-scale behavior of contaminant plumes, primarily through increased lateral spreading resulting from anisotropy. Conceptual models have been updated to include lateral spreading and numerical models of unsaturated flow and transport have revised accordingly. A new robust model based on the concept of a connectivity tensor was developed to describe saturation-dependent anisotropy in strongly heterogeneous soils and has been incorporated into PNNL’s Subsurface Transport Over Multiple Phases (STOMP) simulator. Application to field-scale transport problems have led to a better understanding plume behavior at a number of sites where lateral spreading may have dominated waste

  15. Conductance fluctuations and distribution in disordered chains in presence of an electric field

    International Nuclear Information System (INIS)

    Senouci, K.

    1995-07-01

    A simple Kronig-Penney model for 1D mesoscopic systems with disordered δ-peak and finite width potentials under an electric field is used to study the conductance fluctuations and distributions in different phase states. The electric field allows us to obtain the insulating, transition and metallic regimes. In the superlocalized electron states found previously near the Brillouin zone edges of the corresponding periodic system the conductance fluctuations are smaller than those of the insulating regime corresponding to the vanishing field, but the conductance probability distribution has a similar behaviour. Extensive results are compared to the previous works on higher dimensions and quasi-1D mesoscopic systems in each regime and found to be in good agreement. Further discussions are also included. (author). 33 refs, 11 figs

  16. Gauge structure of neutral-vector field theory. [Massive vector fields, massless limits

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, R; Yokoyama, [Hiroshima univ., Takehara (Japan). Research Inst. for Theoretical Physics

    1975-03-01

    General aspects of gauge structure of neutral-vector field theory are investigated from an extended standpoint, where massive vector fields are treated in a form corresponding to the electromagnetic fields in a general gauge formalism reported previously. All results obtained are shown to have unique massless limits. It is shown that a generalized q-number gauge transformation for fields makes the theory invariant in cooperation with a simultaneous transformation for relevant gauge parameters. A method of differentiation with respect to a gauge variable is found to clarify some essential features of the gauge structure. Two possible types of gauge structure also emerge correspondingly to the massless case. A neutral-vector field theory proposed in a preceding paper is included in the present framework as the most preferable case.

  17. Magnetic field decay in black widow pulsars

    Science.gov (United States)

    Mendes, Camile; de Avellar, Marcio G. B.; Horvath, J. E.; Souza, Rodrigo A. de; Benvenuto, O. G.; De Vito, M. A.

    2018-04-01

    We study in this work the evolution of the magnetic field in `redback-black widow' pulsars. Evolutionary calculations of these `spider' systems suggest that first the accretion operates in the redback stage, and later the companion star ablates matter due to winds from the recycled pulsar. It is generally believed that mass accretion by the pulsar results in a rapid decay of the magnetic field when compared to the rate of an isolated neutron star. We study the evolution of the magnetic field in black widow pulsars by solving numerically the induction equation using the modified Crank-Nicolson method with intermittent episodes of mass accretion on to the neutron star. Our results show that the magnetic field does not fall below a minimum value (`bottom field') in spite of the long evolution time of the black widow systems, extending the previous conclusions for much younger low-mass X-ray binary systems. We find that in this scenario, the magnetic field decay is dominated by the accretion rate, and that the existence of a bottom field is likely related to the fact that the surface temperature of the pulsar does not decay as predicted by the current cooling models. We also observe that the impurity of the pulsar crust is not a dominant factor in the decay of magnetic field for the long evolution time of black widow systems.

  18. Educational Investments and Economic Development: A Field Study.

    Science.gov (United States)

    Champaigne, John

    A study examined the relationship between educational investments and economic development in the small community of Canandaigua, New York. A field study approach was used to collect data pertaining to the city's population characteristics, income characteristics, economic conditions, unemployment rates, and housing conditions. These data were…

  19. Wake-field studies on photonic band gap accelerator cavities

    International Nuclear Information System (INIS)

    Li, D.; Kroll, N.; Stanford Linear Accelerator Center, M/S 26, P.O. Box 4349, Stanford, California; Smith, D.R.; Schultz, S.

    1997-01-01

    We have studied the wake-field of several metal Photonic Band Gap (PBG) cavities which consist of either a square or a hexagonal array of metal cylinders, bounded on top and bottom by conducting or superconducting sheets, surrounded by placing microwave absorber at the periphery or by replacing outer rows of metal cylinders with lossy dielectric ones, or by metallic walls. A removed cylinder from the center of the array constitutes a site defect where a localized electromagnetic mode can occur. While both monopole and dipole wake-fields have been studied, we confine our attention here mainly to the dipole case. The dipole wake-field is produced by modes in the propagation bands which tend to fill the entire cavity more or less uniformly and are thus easy to damp selectively. MAFIA time domain simulation of the transverse wake-field has been compared with that of a cylindrical pill-box comparison cavity. Even without damping the wake-field of the metal PBG cavity is substantially smaller than that of the pill-box cavity and may be further reduced by increasing the size of the lattice. By introducing lossy material at the periphery we have been able to produce Q factors for the dipole modes in the 40 to 120 range without significantly degrading the accelerating mode. copyright 1997 American Institute of Physics

  20. Particle localization in a double-well potential by pseudo-supersymmetric fields

    International Nuclear Information System (INIS)

    Bagrov, V. G.; Samsonov, B. F.; Shamshutdinova, V. V.

    2011-01-01

    We study properties of a particle moving in a double-well potential in the two-level approximation placed in an additional external time-dependent field. Using previously established property (J. Phys. A 41, 244023 (2008)) that any two-level system possesses a pseudo-supersymmetry we introduce the notion of pseudo-supersymmetric field. It is shown that these fields, even if their time dependence is not periodical, may produce the effect of localization of the particle in one of the wells of the double-well potential.

  1. Vadose zone transport field study: Detailed test plan for simulated leak tests

    International Nuclear Information System (INIS)

    AL Ward; GW Gee

    2000-01-01

    The US Department of Energy (DOE) Groundwater/Vadose Zone Integration Project Science and Technology initiative was created in FY 1999 to reduce the uncertainty associated with vadose zone transport processes beneath waste sites at DOE's Hanford Site near Richland, Washington. This information is needed not only to evaluate the risks from transport, but also to support the adoption of measures for minimizing impacts to the groundwater and surrounding environment. The principal uncertainties in vadose zone transport are the current distribution of source contaminants and the natural heterogeneity of the soil in which the contaminants reside. Oversimplified conceptual models resulting from these uncertainties and limited use of hydrologic characterization and monitoring technologies have hampered the understanding contaminant migration through Hanford's vadose zone. Essential prerequisites for reducing vadose transport uncertainly include the development of accurate conceptual models and the development or adoption of monitoring techniques capable of delineating the current distributions of source contaminants and characterizing natural site heterogeneity. The Vadose Zone Transport Field Study (VZTFS) was conceived as part of the initiative to address the major uncertainties confronting vadose zone fate and transport predictions at the Hanford Site and to overcome the limitations of previous characterization attempts. Pacific Northwest National Laboratory (PNNL) is managing the VZTFS for DOE. The VZTFS will conduct field investigations that will improve the understanding of field-scale transport and lead to the development or identification of efficient and cost-effective characterization methods. Ideally, these methods will capture the extent of contaminant plumes using existing infrastructure (i.e., more than 1,300 steel-cased boreholes). The objectives of the VZTFS are to conduct controlled transport experiments at well-instrumented field sites at Hanford to

  2. Dual origin of room temperature sub-terahertz photoresponse in graphene field effect transistors

    Science.gov (United States)

    Bandurin, D. A.; Gayduchenko, I.; Cao, Y.; Moskotin, M.; Principi, A.; Grigorieva, I. V.; Goltsman, G.; Fedorov, G.; Svintsov, D.

    2018-04-01

    Graphene is considered as a promising platform for detectors of high-frequency radiation up to the terahertz (THz) range due to its superior electron mobility. Previously, it has been shown that graphene field effect transistors (FETs) exhibit room temperature broadband photoresponse to incoming THz radiation, thanks to the thermoelectric and/or plasma wave rectification. Both effects exhibit similar functional dependences on the gate voltage, and therefore, it was difficult to disentangle these contributions in previous studies. In this letter, we report on combined experimental and theoretical studies of sub-THz response in graphene field-effect transistors analyzed at different temperatures. This temperature-dependent study allowed us to reveal the role of the photo-thermoelectric effect, p-n junction rectification, and plasmonic rectification in the sub-THz photoresponse of graphene FETs.

  3. Study of high field Nb3Sn superconducting dipoles: electrical insulation based made of ceramic and magnetic design

    International Nuclear Information System (INIS)

    Rochepault, E.

    2012-01-01

    In the framework of LHC upgrades, significant efforts are provided to design accelerator magnets using the superconducting alloy Nb 3 Sn, which allows to reach higher magnetic fields (≥12 T). The aim of this thesis is to propose new computation and manufacturing methods for high field Nb 3 Sn dipoles. A ceramic insulation, previously designed at CEA Saclay, has been tested for the first time on cables, in an accelerator magnet environment. Critical current measures, under magnetic field and mechanical stress, have been carried out in particular. With this test campaign, the current ceramic insulation has been shown to be too weak mechanically and the critical current properties are degraded. Then a study has been conducted, with the objective to improve the mechanical strength of the insulation and better distribute the stress inside the cable. Methods of magnetic design have also been proposed, in order to optimize the coils shape, while fulfilling constraints of field homogeneity, operational margins, forces minimization... Consequently, several optimization codes have been set up. They are based on new methods using analytical formulas. A 2D code has first been written for block designs. Then two 3D codes have been realized for the optimization of dipole ends. The former consists in modeling the coil with elementary blocs and the latter is based on a modeling of the superconducting cables with ribbons. These optimization codes allowed to propose magnetic designs for high field accelerator magnets. (author) [fr

  4. AN ANALYSIS OF THE STUDY PLAN OF THE PROFESSIONALLY ORIENTED BACHELOR STUDY FIELD OF MULTIMEDIA IN ECONOMIC PRACTISE

    Directory of Open Access Journals (Sweden)

    VONDRA, Zdeněk

    2014-12-01

    Full Text Available This paper focuses on the study field of Multimedia in Economic Practise which has been taught at the University of Economics in Prague since 2011. This study field has its first graduates which is the reason for a re-examination of the profile of graduates according to the structure of subjects in the study plan. This paper describes evolution of the study field, its content, main idea and structure of its students. It presents two main groups of occupations for graduates with dependence on requirements for student’s additional independent activities beyond the study. The analytical part shows five examples of comparison of the course relevance according to the opinion of students and academic staff. The conclusions from the survey will enable academic staff of the study field to the reconsider the future development of the study field.

  5. Effective field study of ising model on a double perovskite structure

    Energy Technology Data Exchange (ETDEWEB)

    Ngantso, G. Dimitri; El Amraoui, Y. [LMPHE, (URAC 12), Faculté des Sciences, Université Mohammed V, Rabat (Morocco); Benyoussef, A. [LMPHE, (URAC 12), Faculté des Sciences, Université Mohammed V, Rabat (Morocco); Center of Materials and Nanomaterials, MAScIR, Rabat (Morocco); Hassan II Academy of Science and Technology, Rabat (Morocco); El Kenz, A., E-mail: elkenz@fsr.ac.ma [LMPHE, (URAC 12), Faculté des Sciences, Université Mohammed V, Rabat (Morocco)

    2017-02-01

    By using the effective field theory (EFT), the mixed spin-1/2 and spin-3/2 Ising ferrimagnetic model adapted to a double perovskite structure has been studied. The EFT calculations have been carried out from Ising Hamiltonian by taking into account first and second nearest-neighbors interactions and the crystal and external magnetic fields. Both first- and second-order phase transitions have been found in phase diagrams of interest. Depending on crystal-field values, the thermodynamic behavior of total magnetization indicated the compensation phenomenon existence. The hysteresis behaviors are studied by investigating the reduced magnetic field dependence of total magnetization and a series of hysteresis loops are shown for different reduced temperatures around the critical one. - Highlights: • Magnetic properties of double perovskite Structure have been studied. • Compensation temperature has been observed below the critical temperature. • Hysteresis behaviors have been studied.

  6. Effective field study of ising model on a double perovskite structure

    International Nuclear Information System (INIS)

    Ngantso, G. Dimitri; El Amraoui, Y.; Benyoussef, A.; El Kenz, A.

    2017-01-01

    By using the effective field theory (EFT), the mixed spin-1/2 and spin-3/2 Ising ferrimagnetic model adapted to a double perovskite structure has been studied. The EFT calculations have been carried out from Ising Hamiltonian by taking into account first and second nearest-neighbors interactions and the crystal and external magnetic fields. Both first- and second-order phase transitions have been found in phase diagrams of interest. Depending on crystal-field values, the thermodynamic behavior of total magnetization indicated the compensation phenomenon existence. The hysteresis behaviors are studied by investigating the reduced magnetic field dependence of total magnetization and a series of hysteresis loops are shown for different reduced temperatures around the critical one. - Highlights: • Magnetic properties of double perovskite Structure have been studied. • Compensation temperature has been observed below the critical temperature. • Hysteresis behaviors have been studied.

  7. The LOFT wide field monitor

    DEFF Research Database (Denmark)

    Brandt, Søren; Hernanz, M.; Alvarez, L.

    2012-01-01

    class large area detector (LAD) with a monitor (WFM) instrument based on the coded mask principle, providing coverage of more than 1/3 of the sky. The LAD will provide an effective area ~20 times larger than any previous mission and will by timing studies...... resolution of monitoring instrument to study long term variability of many classes of X-ray sources. The sensitivity of the WFM will be 2.1 mCrab in a one day observation, and 270 mCrab in 3s in observations of in the crowded field of the Galactic Center. The high duty...

  8. Predictive factors for the development of diabetes in women with previous gestational diabetes mellitus

    DEFF Research Database (Denmark)

    Damm, P.; Kühl, C.; Bertelsen, Aksel

    1992-01-01

    OBJECTIVES: The purpose of this study was to determine the incidence of diabetes in women with previous dietary-treated gestational diabetes mellitus and to identify predictive factors for development of diabetes. STUDY DESIGN: Two to 11 years post partum, glucose tolerance was investigated in 241...... women with previous dietary-treated gestational diabetes mellitus and 57 women without previous gestational diabetes mellitus (control group). RESULTS: Diabetes developed in 42 (17.4%) women with previous gestational diabetes mellitus (3.7% insulin-dependent diabetes mellitus and 13.7% non...... of previous patients with gestational diabetes mellitus in whom plasma insulin was measured during an oral glucose tolerance test in late pregnancy a low insulin response at diagnosis was found to be an independent predictive factor for diabetes development. CONCLUSIONS: Women with previous dietary...

  9. Differential Gender Performance on the Major Field Test-Business

    Science.gov (United States)

    Bielinska-Kwapisz, Agnieszka; Brown, F. William

    2013-01-01

    The Major Field Test in Business (MFT-B), a standardized assessment test of business knowledge among undergraduate business seniors, is widely used to measure student achievement. Many previous studies analyzing scores on the MFT-B report gender differences on the exam even after controlling for student's aptitude, general intellectual ability,…

  10. Monte Carlo study of MLC fields for cobalt therapy machine

    Directory of Open Access Journals (Sweden)

    Komanduri M Ayyangar

    2014-01-01

    Full Text Available An automated Multi-Leaf Collimator (MLC system has been developed as add-on for the cobalt-60 teletherapy machines available in India. The goal of the present computational study is to validate the MLC design using Monte Carlo (MC modeling. The study was based on the Kirloskar-supplied Phoenix model machines that closely match the Atomic Energy of Canada Limited (AECL theratron-80 machine. The MLC is a retrofit attachment to the collimator assembly, with 14 non-divergent leaf pairs of 40 mm thick, 7 mm wide, and 150 mm long tungsten alloy plates with rounded edges and 20 mm tongue and 2 mm groove in each leaf. In the present work, the source and collimator geometry has been investigated in detail to arrive at a model that best represents the measured dosimetric data. The authors have studied in detail the proto-I MLC built for cobalt-60. The MLC field sizes were MC simulated for 2 × 2 cm 2 to 14 × 14 cm 2 square fields as well as irregular fields, and the percent depth dose (PDD and profile data were compared with ROPS† treatment planning system (TPS. In addition, measured profiles using the IMATRIXX system‡ were also compared with the MC simulations. The proto-I MLC can define radiation fields up to 14 × 14 cm΂ within 3 mm accuracy. The maximum measured leakage through the leaf ends in closed condition was 3.4% and interleaf leakage observed was 7.3%. Good agreement between MC results, ROPS and IMATRIXX results has been observed. The investigation also supports the hypothesis that optical and radiation field coincidence exists for the square fields studied with the MLC. Plots of the percent depth dose (PDD data and profile data for clinically significant irregular fields have also been presented. The MC model was also investigated to speed up the calculations to allow calculations of clinically relevant conformal beams.

  11. Canine parvovirus in vaccinated dogs: a field study.

    Science.gov (United States)

    Miranda, C; Thompson, G

    2016-04-16

    The authors report a field study that investigated the canine parvovirus (CPV) strains present in dogs that developed the disease after being vaccinated. Faecal samples of 78 dogs that have been vaccinated against CPV and later presented with clinical signs suspected of parvovirus infection were used. Fifty (64.1 per cent) samples tested positive by PCR for CPV. No CPV vaccine type was detected. The disease by CPV-2b occurred in older and female dogs when compared with that by CPV-2c. The clinical signs presented by infected dogs were similar when any of both variants were involved. In most cases of disease, the resulting infection by field variants occurred shortly after CPV vaccination. Two dogs that had been subjected to a complete vaccination schedule and presented with clinical signs after 10 days of vaccination, had the CPV-2c variant associated. The phylogenetic studies showed a close relationship of the isolates in vaccinated dogs to European field strains. Despite the limited sample size in this study, the findings point to the significance of the continuous molecular typing of the virus as a tool to monitor the prevalent circulating CPV strains and access the efficacy of current vaccines. Adjustments on the vaccine types to be used may have to be evaluated again according to each epidemiological situation in order to achieve the dog's optimal immune protection against CPV.

  12. 49 CFR 173.23 - Previously authorized packaging.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Previously authorized packaging. 173.23 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Preparation of Hazardous Materials for Transportation § 173.23 Previously authorized packaging. (a) When the regulations specify a packaging with a specification marking...

  13. The Study of Spherical Cores with a Toroidal Magnetic Field Configuration

    Energy Technology Data Exchange (ETDEWEB)

    Gholipour, Mahmoud [Research Institute for Astronomy and Astrophysics of Maragha (RIAAM)—Maragha, P.O. Box 55134-441 (Iran, Islamic Republic of)

    2017-04-01

    Observational studies of the magnetic fields in molecular clouds have significantly improved the theoretical models developed for the structure and evolution of dense clouds and for the star formation process as well. The recent observational analyses on some cores indicate that there is a power-law relationship between magnetic field and density in the molecular clouds. In this study, we consider the stability of spherical cores with a toroidal magnetic field configuration in the molecular clouds. For this purpose, we model a spherical core that is in magnetostatic equilibrium. Herein, we propose an equation of density structure, which is a modified form of the isothermal Lane–Emden equation in the presence of the toroidal magnetic field. The proposed equation describes the effect of the toroidal magnetic field on the cloud structure and the mass cloud. Furthermore, we found an upper limit for this configuration of magnetic field in the molecular clouds. Then, the virial theorem is used to consider the cloud evolution leading to an equation in order to obtain the lower limit of the field strength in the molecular cloud. However, the results show that the field strength of the toroidal configuration has an important effect on the cloud structure, whose upper limit is related to the central density and field gradient. The obtained results address some regions of clouds where the cloud decomposition or star formation can be seen.

  14. The job satisfaction of principals of previously disadvantaged schools

    African Journals Online (AJOL)

    The aim of this study was to identify influences on the job satisfaction of previously disadvantaged ..... I am still riding the cloud … I hope it lasts. .... as a way of creating a climate and culture in schools where individuals are willing to explore.

  15. Hospital graduate social work field work programs: a study in New York City.

    Science.gov (United States)

    Showers, N

    1990-02-01

    Twenty-seven hospital field work programs in New York City were studied. Questionnaires were administered to program coordinators and 238 graduate social work students participating in study programs. High degrees of program structural complexity and variation were found, indicating a state of art well beyond that described in the general field work literature. High rates of student satisfaction with learning, field instructors, programs, and the overall field work experience found suggest that the complexity of study programs may be more effective than traditional field work models. Statistically nonsignificant study findings indicate areas in which hospital social work departments may develop field work programs consistent with shifting organizational needs, without undue risk to educational effectiveness. Statistically significant findings suggest areas in which inflexibility in program design may be more beneficial in the diagnostic related groups era.

  16. Atom probe field ion microscopy and related topics: A bibliography 1993

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, R.D.; Miller, M.K.; Russell, K.F.

    1994-10-01

    This bibliography, covering the period 1993, includes references related to the following topics: atom probe field ion microscopy (APFIM), field emission (FE), and field ion microscopy (FIM). Technique-oriented studies and applications are included. The references contained in this document were compiled from a variety of sources including computer searches and personal lists of publications. To reduce the length of this document, the references have been reduced to the minimum necessary to locate the articles. The references are listed alphabetically by authors, an Addendum of references missed in previous bibliographies is included.

  17. Atom probe field ion microscopy and related topics: A bibliography 1993

    International Nuclear Information System (INIS)

    Godfrey, R.D.; Miller, M.K.; Russell, K.F.

    1994-10-01

    This bibliography, covering the period 1993, includes references related to the following topics: atom probe field ion microscopy (APFIM), field emission (FE), and field ion microscopy (FIM). Technique-oriented studies and applications are included. The references contained in this document were compiled from a variety of sources including computer searches and personal lists of publications. To reduce the length of this document, the references have been reduced to the minimum necessary to locate the articles. The references are listed alphabetically by authors, an Addendum of references missed in previous bibliographies is included

  18. 22 CFR 40.91 - Certain aliens previously removed.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Certain aliens previously removed. 40.91... IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.91 Certain aliens previously removed. (a) 5-year bar. An alien who has been found inadmissible, whether as a result...

  19. Is email a reliable means of contacting authors of previously published papers? A study of the Emergency Medicine Journal for 2001.

    Science.gov (United States)

    O'Leary, F

    2003-07-01

    To determine whether it is possible to contact authors of previously published papers via email. A cross sectional study of the Emergency Medicine Journal for 2001. 118 articles were included in the study. The response rate from those with valid email addresses was 73%. There was no statistical difference between the type of email address used and the address being invalid (p=0.392) or between the type of article and the likelihood of a reply (p=0.197). More responses were obtained from work addresses when compared with Hotmail addresses (86% v 57%, p=0.02). Email is a valid means of contacting authors of previously published articles, particularly within the emergency medicine specialty. A work based email address may be a more valid means of contact than a Hotmail address.

  20. Does the patients′ educational level and previous counseling affect their medication knowledge?

    Directory of Open Access Journals (Sweden)

    Abdulmalik M Alkatheri

    2013-01-01

    Conclusions: The education level of the patient and previous counseling are positively linked to medication knowledge. Knowledge of the medications′ side effects proved to be the most difficult task for the participants in this study, requiring the highest level of education, and was improved by previous counseling.

  1. Standardization of doctoral study in agricultural and extension education: is the field of study mature enough for achievement of the optimum degree of order?

    Science.gov (United States)

    Briers, G E; Lindner, J R; Shinn, G C; Wingenbach, G W; Baker, M T

    2010-01-01

    Agricultural and extension education--or some derivative name--is a field of study leading to the doctoral degree in universities around the world. Is there are body of knowledge or a taxonomy of the knowledge--e.g., a knowledge domain--that one should possess with a doctorate in agricultural and extension education? The purpose of this paper was to synthesize the work of researchers who attempted to define the field of study, with a taxonomy comprising the knowledge domains (standards) and knowledge objects--structured interrelated sets of data, knowledge, and wisdom--of the field of study. Doctoral study in agricultural and extension education needs a document that provides for rules and guidelines--rules and guidelines that in turn provide for common and repeated use--all leading to achievement of an optimum degree of order in the context of academic, scholarly, and professional practice in agricultural and extension education. Thus, one would know in broad categories the knowledge, skills, and abilities possessed by one who holds a doctoral degree in agricultural and extension education. That is, there would exist a standard for doctoral degrees in agricultural and extension education. A content analysis of three previous attempts to categorize knowledge in agricultural and extension education served as the primary technique to create a new taxonomy--or to confirm an existing taxonomy--for doctoral study in agricultural and extension education. The following coalesced as nine essential knowledge domains for a doctorate in agricultural and extension education: (1) history, philosophy, ethics, and policy; (2) agricultural/rural development; (3) organizational development and change management; (4) planning, needs assessment, and evaluation; (5) learning theory; (6) curriculum development and instructional design; (7) teaching methods and delivery strategies; (8) research methods and tools; and, (9) scholarship and communications.

  2. Gender Differences in the Formation of a Field of Study Choice Set

    Directory of Open Access Journals (Sweden)

    Sigal Alon

    2015-02-01

    Full Text Available Women now surpass men in overall rates of college graduation in many industrialized countries, but sex segregation in fields of study persists. In a world where gender norms have changed but gender stereotypes remain strong, we argue that men’s and women’s attitudes and orientations toward fields of study in college are less constrained by gendered institutions than is the ranking of these fields. Accordingly, the sex segregation in the broader choice set of majors considered by college applicants may be lower than the sex segregation in their first preference field of study selection. With unique data on the broader set of fields considered by applicants to elite Israeli universities, we find support for this theory. The factors that drive the gender gap in the choice of field of study, in particular labor market earnings, risk aversion, and the sex composition of fields, are weaker in the broad set of choices than in the first choice. The result is less segregation in considered majors than in the first choice and, more broadly, different gender patterns in the decision process for the set of considered majors and for the first choice. We consider the theoretical implications of these results.

  3. Behaviour of the interplanetary and magnetospheric electric fields during very intense storms

    International Nuclear Information System (INIS)

    Wu, Lei; Gendrin, R.; Higel, B.

    1982-01-01

    A study is made of the role which a positive (northward) component of the interplanetary magnetic field (IMF) Bsub(z) may play in triggering large magnetic storms. The study is made over a 15 year period (1964-1978) by selecting storms with Ksub(p) >= 7 0 and which are preceded by a Sudden Commencement (Ssc). The correlation between the geomagnetic index Ksub(m) and the three-hourly averaged Bsub(z) is established both on a statistical basis and on a case-by-case study. Storms associated with Bsub(z) > 0 are found to be less intense than those associated with Bsub(z) < 0, but major storms can be also triggered by solar wind events associated with a northward IMF. The relation-ship between interplanetary electric field Esub(γ) and Ksub(m) is also given. By using this relation together with the one between Esub(M) and Ksub(m) which has been established in previous studies (where Esub(M) is the magnetospheric convection electric field), it is possible to study the transfer efficiency of the magnetosphere. It is found that the transfer coefficient ΔEsub(M)/ΔEsub(γ) is much smaller for intense storms than for moderate ones, the latter having been studied in a previous paper (Wu Lei et al., 1981)

  4. Study of the evolution of the boundary of the elastic field with strain hardening, and elastic-plastic behaviour relationships of cubic metals

    International Nuclear Information System (INIS)

    Bui, Huy Duong

    1969-01-01

    In this research thesis on metal strain hardening, the author first discusses the issue of passing from microscopic values to corresponding macroscopic values. If there is generally a correspondence between them, it is not the case for plastic strain. Thus, the author studies the general properties of the boundary of the macroscopic plastic field with respect to single-crystal elastic boundaries. In the second part, the author reports an experimental study of the evolution of the elastic field boundary. In the third part, he develops elastic-plastic behaviour laws for an aggregate of cubic crystals. The objectives are to report experimental results in a more satisfying way than previous studies, and to obtain acceptable physical laws while keeping some properties of conventional laws in order to ensure the solution uniqueness, and to establish minimum principles similar to those of Nodge-Prager and of Greenberg. In order to do so, he introduces a new hypothesis: there is a statistic scattering in initial thresholds of crystals

  5. DTU candidate field models for IGRF-12 and the CHAOS-5 geomagnetic field model

    DEFF Research Database (Denmark)

    Finlay, Chris; Olsen, Nils; Tøffner-Clausen, Lars

    2015-01-01

    We present DTU’s candidate field models for IGRF-12 and the parent field model from which they were derived,CHAOS-5. Ten months of magnetic field observations from ESA’s Swarm mission, together with up-to-date ground observatory monthly means, were used to supplement the data sources previously u...... been documented, but the 2013 pulse has only recently been identified. The spatial signature of the 2013pulse at the core surface, under the Atlantic sector where it is strongest, is well correlated with the 2006 pulse, but anti-correlated with the 2009 pulse....

  6. Numerical study of primordial magnetic field amplification by inflation-produced gravitational waves

    International Nuclear Information System (INIS)

    Kuroyanagi, Sachiko; Tashiro, Hiroyuki; Sugiyama, Naoshi

    2010-01-01

    We numerically study the interaction of inflation-produced magnetic fields with gravitational waves, both of which originate from quantum fluctuations during inflation. The resonance between the magnetic field perturbations and the gravitational waves has been suggested as a possible mechanism for magnetic field amplification. However, some analytical studies suggest that the effect of the inflationary gravitational waves is too small to provide significant amplification. Our numerical study shows more clearly how the interaction affects the magnetic fields and confirms the weakness of the influence of the gravitational waves. We present an investigation based on the magnetohydrodynamic approximation and take into account the differences of the Alfven speed.

  7. SONOGRAPHIC PREDICTION OF SCAR DEHISCENCE IN WOMEN WITH PREVIOUS CAESAREAN SECTION

    Directory of Open Access Journals (Sweden)

    Shubhada Suhas Jajoo

    2018-01-01

    Full Text Available BACKGROUND Caesarean section (Sectio Caesarea is a surgical method for the completion of delivery. After various historical modifications of operative techniques, modern approach consists in the transverse dissection of the anterior wall of the uterus. The rate of vaginal birth after caesarean section was significantly reduced from year to year and the rate of repeated caesarean section is increased during the past 10 years. Evaluation of scar thickness is done by ultrasound, but it is still debatable size of thick scar that would be guiding “cut-off value” for the completion of the delivery method. To better assess the risk of uterine rupture, some authors have proposed sonographic measurement of lower uterine segment thickness near term assuming that there is an inverse correlation between LUS thickness and the risk of uterine scar defect. Therefore, this assessment for the management of women with prior CS may increase safety during labour by selecting women with the lowest risk of uterine rupture. The aim of the study is to study the diagnostic accuracy of sonographic measurements of the Lower Uterine Segment (LUS thickness near term in predicting uterine scar defects in women with prior Caesarean Section (CS. We aim to ascertain the best cut-off values for predicting uterine rupture. MATERIALS AND METHODS 100 antenatal women with history of previous one LSCS who come to attend antenatal clinic will be assessed for scar thickness by transabdominal ultrasonography and its correlation with intraoperative findings. This prospective longitudinal study was conducted for 1 year after IEC approval with inclusion criteria previous one LSCS. Exclusion criteria- 1 Previous myomectomy scar; 2 Previous 2 LSCS; 3 Previous hysterotomy scar. RESULTS Our findings indicate that there is a strong association between degree of LUS thinning measured near term and the risk of uterine scar defect at birth. In our study, optimal cut-off value for predicting

  8. Pulsed Field Gel Electrophoresis (PFGE: a DNA finger printing technique to study the genetic diversity of blood disease bacterium of banana

    Directory of Open Access Journals (Sweden)

    HADIWIYONO

    2011-01-01

    Full Text Available Hadiwiyono, Widada J, Subandiyah S, Fegan F (2011 Pulsed Field Gel Electrophoresis (PFGE: a DNA finger printing technique to study the genetic diversity of blood disease bacterium of banana. Biodiversitas 12: 12-16. Blood disease bacterium (BDB is the most important pathogen of bananas in Indonesia. In some field, the disease incidence reaches over 80%. Epidemiologically, the disease is similar to moko disease in South America and bugtok disease in the Philippines caused by Ralstonia solanacearum race 2. However, BDB is different in phenotype and genotype from the two diseases. Previously BDB was limited in South Sulawesi since 1920s – 1980s and recently was reported in 27 of 30 provinces in Indonesia. Pulsed-Field Gel Electrophoresis (PFGE is a genomic DNA fingerprinting method, which employs rare cutting restriction endonucleases to digest genome prior to electrophoresis using specialized condition to separate of large DNA fragments. The results showed that PFGE analysis was a discriminative tool to study the genetic diversity of BDB. Based on the PFGE analysis, BDB isolates obtained from different localities in Yogyakarta and Central Java were quit diverse.

  9. Simulation study of dynamo structure in reversed field pinch

    International Nuclear Information System (INIS)

    Nagata, A.; Sato, K.I.; Ashida, H.; Amano, T.

    1992-10-01

    The dynamo structure in the reversed field pinch (RFP) is studied through the nonlinear dynamics of single-helicity mode. Simulation is concentrated upon the physical structure of nonlinear interactions of the plasma flow and magnetic fluctuation. The result indicates that when the initial equilibrium profile is deformed by resistive diffusion, the radial flow is driven near the core of the plasma. As this flow forms a vortex structure and magnetic fluctuation grows radially, the dynamo electric field is spirally induced just inside the reversal surface and then the toroidal flux is increased. This dynamo electric field correlates to nonlinear evolution of the kinetic energy of m=1 mode, and the increase of the toroidal flux is originated in the growth process of the magnetic energy of this mode. Consequently, the RFP configuration can be sustained by the single-helicity evolution of m=1 mode alone, and the electric field induced by the interactions of the toroidal velocity and the radial magnetic field is the most dominant source on the dynamo action. (author)

  10. Local Magnetic Fields in Ferromagnetics Studied by Positive Muon Precession

    CERN Multimedia

    2002-01-01

    Positive muons are used to study local magnetic fields in different materials. A polarized muon beam is employed with energies of 30-50 MeV, and the muons are stopped in the target being studied. During its lifetime the muon will precess in the magnetic fields present, and after the decay of the muon the emitted positron is detected in plastic scintillators. The time and angle of the detected positron is used to calculate the magnetic field at the position of the muon in the sample. \\\\ \\\\ The detector system consists of plastic scintillators. Most of the measurements are made in an applied magnetic field. A dilution cryostat is used to produce temperatures down to well below $ 1 ^0 $ K. \\\\ \\\\ The present line of experiments concern mainly: \\item a)~~~~Local magnetism in the paramagnetic state of the Lave's phase type REAl$_{2} $ and RENi$_{2} $ systems ~~~where RE is a rare-earth ion. \\item b)~~~~Local magnetic fields and critical behaviour of the magnetism in Gd metal. \\item c)~~~~Investigation of flux exclu...

  11. A study on the steady-state solutions of a relativistic Bursian diode in the presence of a transverse magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Pramanik, Sourav; Chakrabarti, Nikhil [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Kuznetsov, V. I.; Bakaleinikov, L. A. [Ioffe Institute, St. Petersburg 194021 (Russian Federation)

    2016-08-15

    A comprehensive study on the steady states of a planar vacuum diode driven by a cold relativistic electron beam in the presence of an external transverse magnetic field is presented. The regimes, where no electrons are turned around by the external magnetic field and where they are reflected back to the emitter by the magnetic field, are both considered in a generalized way. The problem is solved by two methods: with the Euler and the Lagrange formulation. Taking non-relativistic limit, the solutions are compared with the similar ones which were obtained for the Bursian diode with a non-relativistic electron beam in previous work [Pramanik et al., Phys. Plasmas 22, 112108 (2015)]. It is shown that, at a moderate value of the relativistic factor of the injected beam, the region of the ambiguous solutions located to the right of the SCL bifurcation point (space charge limit) in the non-relativistic regime disappears. In addition, the dependencies of the characteristic bifurcation points and the transmitted current on the Larmor frequency as well as on the relativistic factor are explored.

  12. A study of reversed field pinch experiments using a new programming mode

    International Nuclear Information System (INIS)

    Kita, Y.

    1979-08-01

    A new mode of external-field programming for setting up a reversed-field pinch (RFP) is tested in STP-1. It involves creating an initial plasma with a screw pinch followed by external-field reversal. The program is done carefully so as to satisfy the equilibrium relation with respect to the minor radius throughout the setting-up phase. Increase of the trapped flux in the plasma by a factor of two is consequently attained, as compared with previous usual programming mode. Actually, at a plasma current of 58 kA, a stable operation time of 13 μsec is achieved with a density of 3.5 x 10 15 cm -3 and a temperature of 20 eV. After 13 μsec stable operation time, the plasma is suddenly crashed down by a violent MHD instability. One dimensional stability analysis based on ideal MHD model is applied to the experimental results. It is found that the instability is m = 1 resistive tearing mode under the influence of viscosity. Using the new programming high current operation at 110 kA is done and results in higher plasma temperature and density of 40 eV and 4.5 x 10 15 cm -3 , respectively. The duration of stable discharge, however, is limited to about 10 μsec, in spite of the expected longer confinement time at the higher temperature. (author)

  13. Magnetic fields and cancer. Epidemiological studies and a synthesis of evidence

    International Nuclear Information System (INIS)

    Feychting, M.

    1995-01-01

    The aims of this thesis were to test the hypothesis that exposure to residential magnetic fields generated by high voltage power lines leads to an increased incidence of childhood cancer, and of leukemia and central nervous system tumors in adults; to investigate important aspects of magnetic field exposure assessment; to synthesize the available evidence on EMF and cancer through different meta-analytical techniques, and to assess some possibilities and limitations of these techniques. A case-control study was conducted within a population of 430,000 subjects living close to power lines. Magnetic field exposure estimated through spot measurements and theoretical calculations of the magnetic fields generated by the power lines at the time of the measurement and prior to diagnosis. The results provide support for the hypothesis of an association between exposure to residential magnetic fields from power lines and childhood leukemia. For adults, there is some evidence of an association for acute and chronic myeloid leukemia. The study's most obvious weakness is the small numbers, and chance may be an explanation for the association between magnetic field exposure and childhood leukemia. Against this speak the consistent results in different subgroups and in the Nordic countries, the magnitude of the association, the obtained confidence intervals, and the dose-response pattern. The heterogeneity among the existing EMF studies does not allow for a meta-analysis where all studies are combined into a common effect estimate. 96 refs

  14. Laboratory degradation studies of 14C-atrazine and -isoproturon in soil from sugarcane cultivated fields under Kenyan tropical conditions.

    Science.gov (United States)

    Getenga, Z M; Dörfler, U; Schroll, R

    2009-06-01

    A study to compare the degradation rates of atrazine (6-chloro-N(2)-ethyl-N(4)-isopropyl-1,3,5-triazine-2,4-diammine) and isoproturon [3-(4-isopropylphenyl)-1,1-dimethylurea] in soils from sugarcane fields with different practices of herbicides application was carried out. (14)C-atrazine was poorly mineralized to (14)CO(2) (1.10% +/- 0.22%) after 139 days of incubation in soil without previous exposure to atrazine. In the same soil also with no previous isoproturon exposure isoproturon was mineralized to (14)CO(2) by 7.70% +/- 0.94%. Atrazine mineralization after 98 days was 13.4% +/- 0.30% in soil which discontinued the use of atrazine in 1997 while it was 89.9% +/- 1.23% in soil in which atrazine is currently being used. The isoproturon mineralization values were 7.24% +/- 0.85% and 22.97% +/- 0.96% in soil which discontinued atrazine and soil currently using atrazine, respectively.

  15. The evening diffuse radio aurora, field-aligned currents and particle precipitation

    International Nuclear Information System (INIS)

    Unwin, R.S.

    1980-01-01

    The relationship of the afternoon/evening diffuse radio aurora, proton and electron precipitation and field-aligned currents is studied with data from the auroral radar at Slope Point, New Zealand, and the ISIS 2 satellite. It is shown that there is a very close association between the radio aurora and (primarily downward) field-aligned currents, which confirms and extends previous work, but that there is no clear relation with either proton or electron precipitation. (author)

  16. THE TOPOLOGICAL CHANGES OF SOLAR CORONAL MAGNETIC FIELDS. II. THE RECLOSING OF AN OPENED FIELD

    International Nuclear Information System (INIS)

    Low, B. C.; Janse, A. M.

    2009-01-01

    This is a study of the spontaneous formation of current sheets responding to the closing of an opened magnetic field by resistive reconnection in an electrically, highly conducting atmosphere outside a unit sphere. Pairs of initial-final equilibrium states are calculated explicitly, taking the field to be composed of three systems of untwisted flux in both states. In the initial state, two of the three flux systems are closed potential fields whereas the third system contains an equilibrium current sheet that keeps the potential fields on its two sides globally open. The final state is an everywhere potential field, with all three flux systems closed, produced by the resistive dissipation of the current sheet in the initial state. The unit sphere is taken to be a rigid, perfectly conducting wall during reconnection, so that the normal flux distribution is unchanged on the unit sphere. Field solutions subject to this unchanging boundary condition are obtained with and without the assumption of axisymmetry. The mathematical model has been designed to show that the topological changes produced by the current-sheet dissipation are simple under axisymmetry but radically different in the absence of axisymmetry, a fundamental point established in the first paper of this series. In the general case, the topological changes imply that other current sheets must have formed. Some of these current sheets form on the separatrix flux surfaces of the multipolar field. Others form throughout the closed-flux systems induced by volumetric changes. The opening and reclosing of magnetic fields during a solar coronal mass ejection may produce a multitude of current sheets not previously anticipated in the current understanding of this phenomenon. Basic to this study is a general topological property of magnetic flux tubes treated separately in the Appendix.

  17. The job satisfaction of principals of previously disadvantaged schools

    African Journals Online (AJOL)

    The aim of this study was to identify influences on the job satisfaction of previously disadvantaged school principals in North-West Province. Evans's theory of job satisfaction, morale and motivation was useful as a conceptual framework. A mixedmethods explanatory research design was important in discovering issues with ...

  18. The TITAN reversed-field-pinch fusion reactor study

    International Nuclear Information System (INIS)

    1990-01-01

    This paper on titan plasma engineering contains papers on the following topics: reversed-field pinch as a fusion reactor; parametric systems studies; magnetics; burning-plasma simulations; plasma transient operations; current drive; and physics issues for compact RFP reactors

  19. Dark field X-ray microscopy for studies of recrystallization

    DEFF Research Database (Denmark)

    Ahl, Sonja Rosenlund; Simons, Hugh; Jakobsen, Anders Clemen

    2015-01-01

    We present the recently developed technique of Dark Field X-Ray Microscopy that utilizes the diffraction of hard X-rays from individual grains or subgrains at the (sub)micrometre- scale embedded within mm-sized samples. By magnifying the diffracted signal, 3D mapping of orientations and strains...... external influences. The capabilities of Dark Field X- Ray Microscopy are illustrated by examples from an ongoing study of recrystallization of 50% cold-rolled Al1050 specimens....

  20. Doxorubicin and ifosfamide combination chemotherapy in previously treated acute leukemia in adults: a Southwest Oncology Group pilot study.

    Science.gov (United States)

    Ryan, D H; Bickers, J N; Vial, R H; Hussein, K; Bottomley, R; Hewlett, J S; Wilson, H E; Stuckey, W J

    1980-01-01

    The Southwest Oncology Group did a limited institutional pilot study of the combination of doxorubicin and ifosfamide in the treatment of previously treated adult patients with acute leukemia. Thirty-four patients received one or two courses of the combination. All patients had received prior chemotherapy and 32 had received prior anthracycline chemotherapy. Three patients died before their responses could be fully evaluated. Fourteen patients achieved complete remission (41%) and one patient achieved partial remission. The complete remission rate was 27% for patients with acute myeloblastic leukemia (myelomonoblastic leukemia, monoblastic leukemia, and erythroleukemia) and 89% for patients with acute lymphocytic and undifferentiated leukemia (ALL). Toxic effects included severe hematologic reactions in 33 of 34 patients, hematuria in six patients, altered sensorium in one patient, and congestive heart failure in one patient. The safety of the combination was established and toxic side effects of this therapy were tolerable. The 89% complete remission rate for previously treated patients with ALL suggests that the combination of doxorubicin and ifosfamide may be particularly effective in ALL.

  1. Engaging the Borders: Empathy, Religious Studies, and Pre-Professional Fields

    Science.gov (United States)

    Trothen, Tracy J.

    2016-01-01

    This article proposes that religious studies instructors can gain pedagogical insights regarding the value and teaching of empathy from pre-professional health care and counseling fields. I present research findings from these fields to support claims that empathic skills are teachable. I then show that empathy has been established within the…

  2. Shape, size, velocity and field-aligned currents of dayside plasma injections: a multi-altitude study

    Directory of Open Access Journals (Sweden)

    A. Marchaudon

    2009-03-01

    Full Text Available On 20 February 2005, Cluster in the outer magnetosphere and Double Star-2 (TC-2 at mid-altitude are situated in the vicinity of the northern cusp/mantle, with Cluster moving sunward and TC-2 anti-sunward. Their magnetic footprints come very close together at about 15:28 UT, over the common field-of-view of SuperDARN radars. Thanks to this conjunction, we determine the velocity, the transverse sizes, perpendicular and parallel to this velocity, and the shape of three magnetic flux tubes of magnetosheath plasma injection. The velocity of the structures determined from the Cluster four-spacecraft timing analysis is almost purely antisunward, in contrast with the antisunward and duskward convection velocity inside the flux tubes. The transverse sizes are defined from the Cluster-TC-2 separation perpendicular to the magnetic field, and from the time spent by a Cluster spacecraft in one structure; they are comprised between 0.6 and 2 RE in agreement with previous studies. Finally, using a comparison between the eigenvectors deduced from a variance analysis of the magnetic perturbation at the four Cluster and at TC-2, we show that the upstream side of the injection flux tubes is magnetically well defined, with even a concave front for the third one giving a bean-like shape, whereas the downstream side is far more turbulent. We also realise the first quantitative comparison between field-aligned currents at Cluster calculated with the curlometer technique and with the single-spacecraft method, assuming infinite parallel current sheets and taking into account the velocity of the injection flux tubes. The results agree nicely, confirming the validity of both methods. Finally, we compare the field-aligned current distribution of the three injection flux tubes at the altitudes of Cluster and TC-2. Both profiles are fairly similar, with mainly a pair of opposite field-aligned currents, upward at low-latitude and downward at high-latitude. In terms of

  3. Study on the system development for evaluating long-term alteration of hydraulic field in Near Field. 3

    International Nuclear Information System (INIS)

    Okutu, Kazuo; Morikawa, Seiji; Taguchi, Katsunori

    2004-02-01

    developed in order to improve their reliability. Furthermore, dynamic alteration action evaluation system consisted of bentonite and cement model was developed, and the long-term dynamic alteration action analysis was performed. In this alteration action analysis, parameters of Ca 2+ ion content of bentonite and leaching ratio of Ca from cement material were considered. The analysis result indicated that the diffusion field, on the set-up condition in this analysis, was kept in the long term. Additionally, the influence of the action of rock that was not covered in his dynamic alteration action evaluation system was arranged. 4) A coupled hydraulic - chemical - dynamical system was developed by integrating the previously developed hydraulic - chemical system and dynamical system. Several analyses were performed to support the thesis that the long term safety of the TRU waste repository is preserved. (author)

  4. A Pseudoproxy-Ensemble Study of Late-Holocene Climate Field Reconstructions Using CCA

    Science.gov (United States)

    Amrhein, D. E.; Smerdon, J. E.

    2009-12-01

    Recent evaluations of late-Holocene multi-proxy reconstruction methods have used pseudoproxy experiments derived from millennial General Circulation Model (GCM) integrations. These experiments assess the performance of a reconstruction technique by comparing pseudoproxy reconstructions, which use restricted subsets of model data, against complete GCM data fields. Most previous studies have tested methodologies using different pseudoproxy noise levels, but only with single realizations for each noise classification. A more robust evaluation of performance is to create an ensemble of pseudoproxy networks with distinct sets of noise realizations and a corresponding reconstruction ensemble that can be evaluated for consistency and sensitivity to random error. This work investigates canonical correlation analysis (CCA) as a late-Holocene climate field reconstruction (CFR) technique using ensembles of pseudoproxy experiments derived from the NCAR CSM 1.4 millennial integration. Three 200-member reconstruction ensembles are computed using pseudoproxies with signal-to-noise ratios (by standard deviation) of 1, 0.5, and 0.25 and locations that approximate the spatial distribution of real-world multiproxy networks. An important component of these ensemble calculations is the independent optimization of the three CCA truncation parameters for each ensemble member. This task is accomplished using an inexpensive discrete optimization algorithm that minimizes both RMS error in the calibration interval and the number of free parameters in the reconstruction model to avoid artificial skill. Within this framework, CCA is investigated for its sensitivity to the level of noise in the pseudoproxy network and the spatial distribution of the network. Warm biases, variance losses, and validation-interval error increase with noise level and vary spatially within the reconstructed fields. Reconstruction skill, measured as grid-point correlations during the validation interval, is lowest in

  5. Current issues in libraries, information science and related fields

    CERN Document Server

    Woodsworth, Anne

    2015-01-01

    This volume is unusual in that the theme is quite broad in scope yet focused on a specific topic; innovations and boundary-pushing studies in areas not usually found in library literature. It examines the periphery of the field surveyed in previous volumes. The chapters are grouped in two categories: professional issues and transforming services.

  6. International Scientific Cooperation in the Field of Spatial Studies

    Directory of Open Access Journals (Sweden)

    Pavel Aleksandrovich Minakir

    2014-06-01

    Full Text Available The paper discusses the existing structure of international cooperation of scientific organizations in the field of regional studies in different parts of the world. The authors define current major organizations that coordinate the work of scientific subdivisions in the field of regional studies in the whole world and also in Europe, North and South America and the Asia-Pacific region. The researchers offer the new term - ‘public-scientific partnership’ (PSP - and discuss PSP mechanisms and its implementation ways that may strengthen regional scientific research in Russia. The authors also debate the idea of creation of the Russian Association of Regional Science

  7. FY1994 annual report on the advanced combustion science in microgravity field

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    Researches were implemented continuously from the previous year on combustion equipment which enables advanced combustion technologies by studying combustion in a microgravity field, for the purpose of preventing environmental pollution caused by diversification of energy sources and exhaust gasses. In joint studies with NASA, research was conducted at both ends concerning the interaction of fuel droplets in a microgravity field; namely, high pressure combustion of binary fuel sprays at NASA against interaction in high pressure spray combustion of binary fuel at Japan side, and ignition and flame spread in microgravity field at NASA against combustion characteristics of organic solid fuels at Japan side. In fiscal 1994, in addition to the test equipment built in the previous year, a fuel droplet combustion test device was manufactured, as were a gas sampling and analyzing device, particle speed measuring device, and laser induced fluorescence measuring device. The tests using these measuring devices and microgravity test equipment were carried out 112 times, thereby establishing the measuring method of flame structure which was an objective of the present year. (NEDO)

  8. A brief report on the statistical study of net electric current in solar active regions with longitudinal fields of opposite polarity

    International Nuclear Information System (INIS)

    Gao Yu

    2013-01-01

    Dynamic processes occurring in solar active regions are dominated by the solar magnetic field. As of now, observations using a solar magnetograph have supplied us with the vector components of a solar photospheric magnetic field. The two transverse components of a photospheric magnetic field allow us to compute the amount of electric current. We found that the electric current in areas with positive (negative) polarity due to the longitudinal magnetic field have both positive and negative signs in an active region, however, the net current is found to be an order-of-magnitude less than the mean absolute magnitude and has a preferred sign. In particular, we have statistically found that there is a systematic net electric current from areas with negative (positive) polarity to areas with positive (negative) polarity in solar active regions in the northern (southern) hemisphere, but during the solar minimum this tendency is reversed over time at some latitudes. The result indicates that there is weak net electric current in areas of solar active regions with opposite polarity, thus providing further details about the hemispheric helicity rule found in a series of previous studies.

  9. GPU-accelerated FDTD modeling of radio-frequency field-tissue interactions in high-field MRI.

    Science.gov (United States)

    Chi, Jieru; Liu, Feng; Weber, Ewald; Li, Yu; Crozier, Stuart

    2011-06-01

    The analysis of high-field RF field-tissue interactions requires high-performance finite-difference time-domain (FDTD) computing. Conventional CPU-based FDTD calculations offer limited computing performance in a PC environment. This study presents a graphics processing unit (GPU)-based parallel-computing framework, producing substantially boosted computing efficiency (with a two-order speedup factor) at a PC-level cost. Specific details of implementing the FDTD method on a GPU architecture have been presented and the new computational strategy has been successfully applied to the design of a novel 8-element transceive RF coil system at 9.4 T. Facilitated by the powerful GPU-FDTD computing, the new RF coil array offers optimized fields (averaging 25% improvement in sensitivity, and 20% reduction in loop coupling compared with conventional array structures of the same size) for small animal imaging with a robust RF configuration. The GPU-enabled acceleration paves the way for FDTD to be applied for both detailed forward modeling and inverse design of MRI coils, which were previously impractical.

  10. Comparison study of toroidal-field divertors for a compact reversed-field pinch reactor

    International Nuclear Information System (INIS)

    Bathke, C.G.; Krakowski, R.A.; Miller, R.L.

    1985-01-01

    Two divertor configurations for the Compact Reversed-Field Pinch Reactor (CRFPR) based on diverting the minority (toroidal) field have been reported. A critical factor in evaluating the performance of both poloidally symmetric and bundle divertor configurations is the accurate determination of the divertor connection length and the monitoring of magnetic islands introduced by the divertors, the latter being a three-dimensional effect. To this end the poloidal-field, toroidal-field, and divertor coils and the plasma currents are simulated in three dimensions for field-line tracings in both the divertor channel and the plasma-edge regions. The results of this analysis indicate a clear preference for the poloidally symmetric toroidal-field divertor. Design modifications to the limiter-based CRFPR design that accommodate this divertor are presented

  11. Magnetic fields in cosmology

    International Nuclear Information System (INIS)

    Madsen, M.S.

    1989-01-01

    The possible role of a large-scale relic magnetic field in the history of the Universe is considered. The perturbation of the cosmic microwave back-ground radiation on large angular scales due to a homogeneous magnetic field is estimated in a simple relativistic model. This allows corresponding limits to be placed on the magnitude of any such large-scale relic magnetic field at the present time. These limits are essentially the strongest which can be set on the largest scales. A corresponding bound is obtained by use of the requirement that the field should not spoil the predictions of primordial nucleosynthesis. It is noted that the existence of large-scale cosmic magnetic fields would circumvent the limits previously set - also on the basis of nucleosynthesis considerations - on the large-scale anisotropy now present in the Universe. (author)

  12. Enhanced Field Emission Studies on Niobium Surfaces Relevant to High Field Superconducting Radio-Frequency Devices

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tong [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2002-09-18

    Enhanced field emission (EFE) presents the main impediment to higher acceleration gradients in superconducting niobium (Nb) radiofrequency cavities for particle accelerators. The strength, number and sources of EFE sites strongly depend on surface preparation and handling. The main objective of this thesis project is to systematically investigate the sources of EFE from Nb, to evaluate the best available surface preparation techniques with respect to resulting field emission, and to establish an optimized process to minimize or eliminate EFE. To achieve these goals, a scanning field emission microscope (SFEM) was designed and built as an extension to an existing commercial scanning electron microscope (SEM). In the SFEM chamber of ultra high vacuum, a sample is moved laterally in a raster pattern under a high voltage anode tip for EFE detection and localization. The sample is then transferred under vacuum to the SEM chamber equipped with an energy-dispersive x-ray spectrometer for individual emitting site characterization. Compared to other systems built for similar purposes, this apparatus has low cost and maintenance, high operational flexibility, considerably bigger scan area, as well as reliable performance. EFE sources from planar Nb have been studied after various surface preparation, including chemical etching and electropolishing, combined with ultrasonic or high-pressure water rinse. Emitters have been identified, analyzed and the preparation process has been examined and improved based on EFE results. As a result, field-emission-free or near field-emission-free surfaces at ~140 MV/m have been consistently achieved with the above techniques. Characterization on the remaining emitters leads to the conclusion that no evidence of intrinsic emitters, i.e., no fundamental electric field limit induced by EFE, has been observed up to ~140 MV/m. Chemically etched and electropolished Nb are compared and no significant difference is observed up to ~140 MV/m. To

  13. Enhanced Field Emission Studies on Niobium Surfaces Relevant to High Field Superconducting Radio-Frequency Devices

    International Nuclear Information System (INIS)

    Tong Wang

    2002-01-01

    Enhanced field emission (EFE) presents the main impediment to higher acceleration gradients in superconducting niobium (Nb) radio frequency cavities for particle accelerators. The strength, number and sources of EFE sites strongly depend on surface preparation and handling. The main objective of this thesis project is to systematically investigate the sources of EFE from Nb, to evaluate the best available surface preparation techniques with respect to resulting field emission, and to establish an optimized process to minimize or eliminate EFE. To achieve these goals, a scanning field emission microscope (SFEM) was designed and built as an extension to an existing commercial scanning electron microscope (SEM). In the SFEM chamber of ultra high vacuum, a sample is moved laterally in a raster pattern under a high voltage anode tip for EFE detection and localization. The sample is then transferred under vacuum to the SEM chamber equipped with an energy-dispersive x-ray spectrometer for individual emitting site characterization. Compared to other systems built for similar purposes, this apparatus has low cost and maintenance, high operational flexibility, considerably bigger scan area, as well as reliable performance. EFE sources from planar Nb have been studied after various surface preparation, including chemical etching and electropolishing, combined with ultrasonic or high-pressure water rinse. Emitters have been identified, analyzed and the preparation process has been examined and improved based on EFE results. As a result, field-emission-free or near field-emission-free surfaces at ∼140 MV/m have been consistently achieved with the above techniques. Characterization on the remaining emitters leads to the conclusion that no evidence of intrinsic emitters, i.e., no fundamental electric field limit induced by EFE, has been observed up to ∼140 MV/m. Chemically etched and electropolished Nb are compared and no significant difference is observed up to ∼140 MV

  14. A comparison of forest height prediction from FIA field measurement and LiDAR data via spatial models

    Science.gov (United States)

    Yuzhen Li

    2009-01-01

    Previous studies have shown a high correspondence between tree height measurements acquired from airborne LiDAR and that those measured using conventional field techniques. Though these results are very promising, most of the studies were conducted over small experimental areas and tree height was measured carefully or using expensive instruments in the field, which is...

  15. ATLANTIC DIP: simplifying the follow-up of women with previous gestational diabetes.

    LENUS (Irish Health Repository)

    Noctor, E

    2013-11-01

    Previous gestational diabetes (GDM) is associated with a significant lifetime risk of type 2 diabetes. In this study, we assessed the performance of HbA1c and fasting plasma glucose (FPG) measurements against that of 75 g oral glucose tolerance testing (OGTT) for the follow-up screening of women with previous GDM.

  16. Reservoir Simulation on the Cerro Prieto Geothermal Field: A Continuing Study

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda, M.; Marquez, R.; Arellano, V.; Esquer, C.A.

    1983-12-15

    The Cerro Prieto geothermal field is a liquid-dominated geothermal reservoir of complex geological and hydrological structure. It is located at the southern end of the Salton-Mexicali trough which includes other geothermal anomalies as Heber and East Mesa. Although in 1973, the initial power plant installed capacity was 75 MW of electrical power, this amount increased to 180 MW in 1981 as field development continued. It is expected to have a generating capacity of 620 MW by the end of 1985, when two new plants will be completely in operation. Questions about field deliverability, reservoir life and ultimate recovery related to planned installations are being presently asked. Numerical modeling studies can give very valuable answers to these questions, even at the early stages in the development of a field. An effort to simulate the Cerro Prieto geothermal reservoir has been undergoing for almost two years. A joint project among Comision Federal de Electricidad (CFE), Instituto de Investigaciones Electricas (IIE) and Intercomp of Houstin, Texas, was created to perform reservoir engineering and simulation studies on this field. The final project objective is tosimulate the behavior of the old field region when production from additional wells located in the undeveloped field zones will be used for feeding the new power plants.

  17. Generation of uniform magnetic field using a spheroidal helical coil structure

    International Nuclear Information System (INIS)

    Öztürk, Yavuz; Aktaş, Bekir

    2016-01-01

    Uniformity of magnetic fields are of great importance especially in magnetic resonance studies, namely in magnetic resonance spectroscopy applications (NMR, FMR, ESR, EPR etc.) and magnetic resonance imaging applications (MRI, FMRI). Field uniformity is also required in some other applications such as eddy current probes, magnetometers, magnetic traps, particle counters etc. Here we proposed a coil winding regime, which follows the surface of a spheroid (an ellipsoid of rotation); in light of previous theoretical studies suggesting perfect uniformity for a constant ampere per turn in the axial direction thereof. We demonstrated our theoretical results from finite element calculations suggesting 0.15% of field uniformity for the proposed structure, which we called a Spheroidal Helical Coil. (paper)

  18. Mapping Women's and Gender Studies in the Academic Field in Slovenia

    Science.gov (United States)

    Gaber, Milica Antic

    2017-01-01

    The aim of the present paper is to map the development of women's and gender studies (WGS) in the academic field in Slovenia. Slovenia is the first of the former Yugoslav state republics in which WGS have succeeded in entering the academic field and becoming part of institutionalised university study. In this paper we will ask the following…

  19. A Guide to Field Notes for Qualitative Research: Context and Conversation.

    Science.gov (United States)

    Phillippi, Julia; Lauderdale, Jana

    2018-02-01

    Field notes are widely recommended in qualitative research as a means of documenting needed contextual information. With growing use of data sharing, secondary analysis, and metasynthesis, field notes ensure rich context persists beyond the original research team. However, while widely regarded as essential, there is not a guide to field note collection within the literature to guide researchers. Using the qualitative literature and previous research experience, we provide a concise guide to collection, incorporation, and dissemination of field notes. We provide a description of field note content for contextualization of an entire study as well as individual interviews and focus groups. In addition, we provide two "sketch note" guides, one for study context and one for individual interviews or focus groups for use in the field. Our guides are congruent with many qualitative and mixed methodologies and ensure contextual information is collected, stored, and disseminated as an essential component of ethical, rigorous qualitative research.

  20. Coulomb scattering in field and photofield emission

    International Nuclear Information System (INIS)

    Donders, P.J.; Lee, M.J.G.

    1987-01-01

    An anomalous high-energy tail has been observed in the measured total energy distribution (TED) in photofield emission from tungsten. The strength of this tail is proportional to the product of the photofield emission current and the total emission current. Similar high- and low-energy tails in the TED's in field emission, which have previously been reported by several workers, are also observed. In any given measurement, the fraction of the total photofield-emission current in the anomalous photofield-emission tail is approximately equal to the fraction of the total field-emission current in the anomalous field-emission tail. Measurements of both the absolute strengths and energy dependences of the anomalous tails are reported. The experimental observations are consistent with the predictions of a classical calculation of the energy transfer that results from the Coulomb interaction between electrons in the vacuum near the field emitter. The various internal mechanisms that have previously been invoked to account for the tails in field-emission TED's do not appear to contribute significantly to the anomalous distributions observed in the present work

  1. Consistent force fields for saccharides

    DEFF Research Database (Denmark)

    Rasmussen, Kjeld

    1999-01-01

    Consistent force fields for carbohydrates were hitherto developed by extensive optimization ofpotential energy function parameters on experimental data and on ab initio results. A wide range of experimental data is used: internal structures obtained from gas phase electron diffraction and from x......-anomeric effects are accounted for without addition of specific terms. The work is done in the framework of the Consistent Force Field which originatedin Israel and was further developed in Denmark. The actual methods and strategies employed havebeen described previously. Extensive testing of the force field...

  2. A study: Effect of Students Peer Assisted Learning on Magnetic Field Achievement

    International Nuclear Information System (INIS)

    Mueanploy, Wannapa

    2016-01-01

    This study is the case study of Physic II Course for students of Pathumwan Institute of Technology. The purpose of this study is: 1) to develop cooperative learning method of peer assisted learning (PAL), 2) to compare the learning achievement before and after studied magnetic field lesson by cooperative learning method of peer assisted learning. The population was engineering students of Pathumwan Institute of Technology (PIT’s students) who registered Physic II Course during year 2014. The sample used in this study was selected from the 72 students who passed in Physic I Course. The control groups learning magnetic fields by Traditional Method (TM) and experimental groups learning magnetic field by method of peers assisted learning. The students do pretest before the lesson and do post-test after the lesson by 20 items achievement tests of magnetic field. The post-test higher than pretest achievement significantly at 0.01 level. (paper)

  3. Transient interaction model of electromagnetic field generated by lightning current pulses and human body

    International Nuclear Information System (INIS)

    Iváncsy, T; Kiss, I; Tamus, Z Á; Szücs, L

    2015-01-01

    The lightning current generates time-varying magnetic field near the down-conductor and the down-conductors are mounted on the wall of the buildings where residential places might be situated. It is well known that the rapidly changing magnetic fields can generate dangerous eddy currents in the human body.The higher duration and gradient of the magnetic field can cause potentially life threatening cardiac stimulation. The coupling mechanism between the electromagnetic field and the human body is based on a well-known physical phenomena (e.g. Faradays law of induction). However, the calculation of the induced current is very complicated because the shape of the organs is complex and the determination of the material properties of living tissues is difficult, as well. Our previous study revealed that the cardiac stimulation is independent of the rising time of the lightning current and only the peak of the current counts.In this study, the authors introduce an improved model of the interaction of electromagnetic fields of lighting current near down-conductor and human body. Our previous models are based on the quasi stationer field calculations, the new improved model is a transient model. This is because the magnetic field around the down-conductor and in the human body can be determined more precisely, therefore the dangerous currents in the body can be estimated. (paper)

  4. Graphene-graphite oxide field-effect transistors.

    Science.gov (United States)

    Standley, Brian; Mendez, Anthony; Schmidgall, Emma; Bockrath, Marc

    2012-03-14

    Graphene's high mobility and two-dimensional nature make it an attractive material for field-effect transistors. Previous efforts in this area have used bulk gate dielectric materials such as SiO(2) or HfO(2). In contrast, we have studied the use of an ultrathin layered material, graphene's insulating analogue, graphite oxide. We have fabricated transistors comprising single or bilayer graphene channels, graphite oxide gate insulators, and metal top-gates. The graphite oxide layers show relatively minimal leakage at room temperature. The breakdown electric field of graphite oxide was found to be comparable to SiO(2), typically ~1-3 × 10(8) V/m, while its dielectric constant is slightly higher, κ ≈ 4.3. © 2012 American Chemical Society

  5. Raw data from orientation studies in crystalline rock areas of the southeastern United States. [Maps, tables of field data and analytical data for sections of North and South Carolina and Georgia, previously reported sites of uranium mineralization

    Energy Technology Data Exchange (ETDEWEB)

    Price, V.

    1976-03-01

    Raw data are presented on orientation studies conducted in crystalline rock areas of the Southeast which were chosen because of published references to uranium mineralization. Preliminary data for four orientation study areas are included. These areas are Lamar County, Georgia; Oconee County, South Carolina; Brush Creek, North Carolina; and North Harper, North Carolina. Sample locality maps, tables of field data, and tables of analytical data are included for each study area. (JGB)

  6. Matrix model approximations of fuzzy scalar field theories and their phase diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Tekel, Juraj [Department of Theoretical Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska Dolina, Bratislava, 842 48 (Slovakia)

    2015-12-29

    We present an analysis of two different approximations to the scalar field theory on the fuzzy sphere, a nonperturbative and a perturbative one, which are both multitrace matrix models. We show that the former reproduces a phase diagram with correct features in a qualitative agreement with the previous numerical studies and that the latter gives a phase diagram with features not expected in the phase diagram of the field theory.

  7. A comparison of morbidity associated with placenta previa with and without previous caesarean sections

    International Nuclear Information System (INIS)

    Baqai, S.; Siraj, A.; Noor, N.

    2018-01-01

    To compare the morbidity associated with placenta previa with and without previous caesarean sections. Study Design: Retrospective comparative study. Place and Duration of Study: From March 2014 till March 2016 in the department of Obstetrics and Gynaecology at PNS Shifa hospital Karachi. Material and Methods: After the approval from hospital ethical committee, antenatal patients with singleton pregnancy of gestational age >32 weeks, in the age group of 20-40 years diagnosed to have placenta previa included in the study. All patients with twin pregnancy less than 20 years and more than 40 years of age were excluded. The records of all patients fulfilling the inclusion criteria were reviewed. Data had been collected for demographic and maternal variables, placenta previa, history of previous lower segment caesarean section (LSCS), complications associated with placenta previa and techniques used to control blood loss were recorded. Results: During the study period, 6879 patients were delivered in PNS Shifa, out of these, 2060 (29.9%) had caesarean section out of these, 47.3% patients had previous history of LSCS. Thirty three (1.6%) patients were diagnosed to have placenta previa and frequency of placenta previa was significantly higher in patients with previous history of LSCS than previous normal delivery of LSCS i.e. 22 vs. 11 (p=0.023). It was observed that the frequency of morbidly adherent placenta (MAP) and Intensive care unit (ICU) stay were significantly higher in patients with previous history of LSCS than previous history of normal delivery. Conclusion: Frequency of placenta previa was significantly higher in patients with history of LSCS. Also placenta previa remains a major risk factor for various maternal complications. (author)

  8. Electric field controlled reversible magnetic anisotropy switching studied by spin rectification

    International Nuclear Information System (INIS)

    Zhou, Hengan; Fan, Xiaolong; Wang, Fenglong; Jiang, Changjun; Rao, Jinwei; Zhao, Xiaobing; Xue, Desheng; Gui, Y. S.; Hu, C.-M.

    2014-01-01

    In this letter, spin rectification was used to study the electric field controlled dynamic magnetic properties of the multiferroic composite which is a Co stripe with induced in-plane anisotropy deposited onto a Pb(Mg 1∕3 Nb 2∕3 )O 3 -PbTiO 3 substrate. Due to the coupling between piezoelectric and magnetoelastic effects, a reversible in-plane anisotropy switching has been realized by varying the history of the applied electric field. This merit results from the electric hysteresis of the polarization in the nonlinear piezoelectric regime, which has been proved by a butterfly type electric field dependence of the in-plane anisotropy field. Moreover, the electric field dependent effective demagnetization field and linewidth have been observed at the same time

  9. Gendered transitions to adulthood by college field of study in the United States

    OpenAIRE

    Siqi Han; Dmitry Tumin; Zhenchao Qian

    2016-01-01

    Background: Field of study may influence the timing of transitions to the labor market, marriage, and parenthood among college graduates. Research to date has yet to study how field of study is associated with the interweaving of these transitions in the USA. Objective: The current study examines gendered influences of college field of study on transitions to a series of adult roles, including full-time work, marriage, and parenthood. Methods: We use Cox proportional hazards models and ...

  10. Time-resolved particle image velocimetry and laser doppler anemometry study of the turbulent flow field of bileaflet mechanical mitral prostheses.

    Science.gov (United States)

    Akutsu, Toshinosuke; Fukuda, Takamasa

    2005-01-01

    Dynamic particle image velocimetry (PIV) was applied to the study of the flow field associated with prosthetic heart valves. The results were compared with those of laser Doppler anemometry (LDA). Anatomically and antianatomically oriented Jyros (JR) and St. Jude Medical (SJM) valves were compared in the mitral position to study the effects of valve design on the downstream flow field. The experimental program used a dynamic PIV system utilizing high-speed, high-resolution video to map the true time-resolved velocity field inside the simulated ventricle. This system was complemented by a study using the more traditional LDA system for comparison. Based on the experimental data, the following general conclusions can be made. High-resolution dynamic PIV can capture true chronological changes in the velocity and turbulence fields. It also produces very detailed velocity and turbulence information comparable to the LDA results. In the vertical measuring plane that passes both the center of the aortic and mitral valves (A-A section), the two valves (the SJM and the JR) show distinct circulatory flow patterns when the valve is installed in the antianatomical orientation. Small differences in valve design can generate noticeable differences, particularly during the accelerating flow phase. The SJM valve maintains a relatively high velocity through the central orifice; the curved leaflets of the JR valve generate higher velocities with a divergent flow during the accelerating and peak flow phases. In the velocity field directly below the mitral valve and normal to the previous measuring plane (B-B section), where characteristic differences in valve design will be visible, symmetrical twin circulations were observed because of the divergent nature of the flow generated by the two inclined half-disks installed in the antianatomical orientation. The SJM valve, with a central downward flow near the valve, is contrasted with the JR valve, which has a peripheral downward

  11. Commentary on "Studying eyewitness investigations in the field": a look forward.

    Science.gov (United States)

    Steblay, Nancy Kay

    2008-02-01

    Schacter et al. (2007, this issue) address the controversy surrounding an Illinois pilot project that attempted to compare sequential versus simultaneous police lineup formats. The statement by these experts will guide the design and execution of future field lineup experiments. This commentary discusses three aspects of field studies that pose challenges as lineup experiments are interpreted: the imprecise meaning of the dependent measure (eyewitness decisions), the limitations of single studies, and the necessity to devise public policy from incomplete knowledge. A combination of laboratory and field information provides the means to determine best practices in eyewitness identification procedures.

  12. Effect of high magnetic fields on the charge density wave properties of KMo 6O 17

    Science.gov (United States)

    Rötger, A.; Dumas, J.; Marcus, J.; Schlenker, C.; Ulmet, J. P.; Audouard, A.; Askenazy, S.

    1992-03-01

    The electrical resistivity of the purple bronze KMo 6O 17 has been studied between 2 and 88 K with pulsed magnetic fields up to 35 T. Several anomalies are found on the curves Δρ/ρ(B) at different temperatures. The low field results are compared with previous measurements of susceptibility and magnetization. A phase diagram which may show a field displaced charge density wave instability and field induced transitions is proposed.

  13. Modulation of the wall-heat transfer in turbulent thermomagnetic convection by magnetic field gradients

    NARCIS (Netherlands)

    Kenjeres, S.; Zinsmeester, R.; Pyrda, L.; Fornalik-Wajs, E.; Szmyd, J.

    2015-01-01

    We present combined experimental and numerical studies of the heat transfer of paramagnetic or diamagnetic fluid inside a differentially heated cubical enclosure subjected to the magnetic field gradients of different strength and orientation. In contrast to the previously reported studies in

  14. Dosimetry, instrumentation and exposure chambers for dc magnetic field studies

    International Nuclear Information System (INIS)

    Tenforde, T.S.

    1979-03-01

    The principal objective of this report is to describe in detail an exposure chamber that was developed at the Lawrence Berkeley Laboratory for automated, noninvasive studies of rodent physiology during exposure to high DC magnetic fields. A second objective is to discuss some of the unique instrumentation problems that must be overcome in order to record bioelectric signals from laboratory animals in the presence of a magnetic field. Finally, a description will be given of the various dosimetry techniques that can be employed for quantitation of magnetic field strength

  15. Sunburn and sun-protective behaviors among adults with and without previous nonmelanoma skin cancer: a population-based study

    Science.gov (United States)

    Fischer, Alexander H.; Wang, Timothy S.; Yenokyan, Gayane; Kang, Sewon; Chien, Anna L.

    2016-01-01

    Background Individuals with previous nonmelanoma skin cancer (NMSC) are at increased risk for subsequent skin cancer, and should therefore limit UV exposure. Objective To determine whether individuals with previous NMSC engage in better sun protection than those with no skin cancer history. Methods We pooled self-reported data (2005 and 2010 National Health Interview Surveys) from US non-Hispanic white adults (758 with and 34,161 without previous NMSC). We calculated adjusted prevalence odds ratios (aPOR) and 95% confidence intervals (95% CI), taking into account the complex survey design. Results Individuals with previous NMSC versus no history of NMSC had higher rates of frequent use of shade (44.3% versus 27.0%; aPOR=1.41; 1.16–1.71), long sleeves (20.5% versus 7.7%; aPOR=1.55; 1.21–1.98), a wide-brimmed hat (26.1% versus 10.5%; aPOR=1.52; 1.24–1.87), and sunscreen (53.7% versus 33.1%; aPOR=2.11; 95% CI=1.73–2.59), but did not have significantly lower odds of recent sunburn (29.7% versus 40.7%; aPOR=0.95; 0.77–1.17). Among subjects with previous NMSC, recent sunburn was inversely associated with age, sun avoidance, and shade but not sunscreen. Limitations Self-reported cross-sectional data and unavailable information quantifying regular sun exposure. Conclusion Physicians should emphasize sunburn prevention when counseling patients with previous NMSC, especially younger adults, focusing on shade and sun avoidance over sunscreen. PMID:27198078

  16. Near field plasmon and force microscopy

    OpenAIRE

    de Hollander, R.B.G.; van Hulst, N.F.; Kooyman, R.P.H.

    1995-01-01

    A scanning plasmon near field optical microscope (SPNM) is presented which combines a conventional far field surface plasmon microscope with a stand-alone atomic force microscope (AFM). Near field plasmon and force images are recorded simultaneously both with a lateral resolution limited by the probe size to about 20 nm. At variance to previous work, utilizing a scanning tunneling microscope (STM) with a metallic tip, a dielectric silicon-nitride tip is used in contact mode. This arrangement ...

  17. Field penetration induced charge redistribution effects on the field emission properties of carbon nanotubes - a first-principle study

    International Nuclear Information System (INIS)

    Chen, C.-W.; Lee, M.-H.; Clark, S.J.

    2004-01-01

    The effect of field penetration induced charge redistribution on the field emission properties of carbon nanotubes (CNTs) have been studied by the first-principle calculations. It is found that the carbon nanotube becomes polarized under external electric field leading to a charge redistribution. The resulting band bending induced by field penetration into the nanotube tip surface can further reduce the effective workfunction of the carbon nanotubes. The magnitude of the redistributed charge ΔQ is found to be nearly linear to the applied external field strength. In addition, we found that the capped (9, 0) zigzag nanotube demonstrates better field emission properties than the capped (5, 5) armchair nanotube due to the fact that the charge redistribution of π electrons along the zigzag-like tube axis is easier than for the armchair-like tube. The density of states (DOS) of the capped region of the nanotube is found to be enhanced with a value 30% higher than that of the sidewall part for the capped (5, 5) nanotube and 40% for the capped (9, 0) nanotube under an electric field of 0.33 V/A. Such enhancements of the DOS at the carbon nanotube tip show that electrons near the Fermi level will emit more easily due to the change of the surface band structure resulting from the field penetration in a high field

  18. Previous experiences and emotional baggage as barriers to lifestyle change - a qualitative study of Norwegian Healthy Life Centre participants.

    Science.gov (United States)

    Følling, Ingrid S; Solbjør, Marit; Helvik, Anne-S

    2015-06-23

    Changing lifestyle is challenging and difficult. The Norwegian Directorate of Health recommends that all municipalities establish Healthy Life Centres targeted to people with lifestyle issues. Little is known about the background, experiences and reflections of participants. More information is needed about participants to shape effective lifestyle interventions with lasting effect. This study explores how participants in a lifestyle intervention programme describe previous life experiences in relation to changing lifestyle. Semi-structured qualitative in-depth interviews were performed with 23 participants (16 women and 7 men) aged 18 - 70 years. The data were analysed using systematic text condensation searching for issues describing participants' responses, and looking for the essence, aiming to share the basis of life-world experiences as valid knowledge. Participants identified two main themes: being stuck in old habits, and being burdened with emotional baggage from their previous negative experiences. Participants expressed a wish to change their lifestyles, but were unable to act in accordance with the health knowledge they possessed. Previous experiences with lifestyle change kept them from initiating attempts without professional assistance. Participants also described being burdened by an emotional baggage with problems from childhood and/or with family, work and social life issues. Respondents said that they felt that emotional baggage was an important explanation for why they were stuck in old habits and that conversely, being stuck in old habits added load to their already emotional baggage and made it heavier. Behavioural change can be hard to perform as psychological distress from life baggage can influence the ability to change. The study participants' experience of being stuck in old habits and having substantial emotional baggage raises questions as to whether or not Healthy Life Centres are able to help participants who need to make a lifestyle

  19. Previous Fractures at Multiple Sites Increase the Risk for Subsequent Fractures: The Global Longitudinal Study of Osteoporosis in Women

    Science.gov (United States)

    Gehlbach, Stephen; Saag, Kenneth G.; Adachi, Jonathan D.; Hooven, Fred H.; Flahive, Julie; Boonen, Steven; Chapurlat, Roland D.; Compston, Juliet E.; Cooper, Cyrus; Díez-Perez, Adolfo; Greenspan, Susan L.; LaCroix, Andrea Z.; Netelenbos, J. Coen; Pfeilschifter, Johannes; Rossini, Maurizio; Roux, Christian; Sambrook, Philip N.; Silverman, Stuart; Siris, Ethel S.; Watts, Nelson B.; Lindsay, Robert

    2016-01-01

    Previous fractures of the hip, spine, or wrist are well-recognized predictors of future fracture, but the role of other fracture sites is less clear. We sought to assess the relationship between prior fracture at 10 skeletal locations and incident fracture. The Global Longitudinal Study of Osteoporosis in Women (GLOW) is an observational cohort study being conducted in 17 physician practices in 10 countries. Women ≥ 55 years answered questionnaires at baseline and at 1 and/or 2 years (fractures in previous year). Of 60,393 women enrolled, follow-up data were available for 51,762. Of these, 17.6%, 4.0%, and 1.6% had suffered 1, 2, or ≥3 fractures since age 45. During the first 2 years of follow-up, 3149 women suffered 3683 incident fractures. Compared with women with no prior fractures, women with 1, 2, or ≥ 3 prior fractures were 1.8-, 3.0-, and 4.8-fold more likely to have any incident fracture; those with ≥3 prior fractures were 9.1-fold more likely to sustain a new vertebral fracture. Nine of 10 prior fracture locations were associated with an incident fracture. The strongest predictors of incident spine and hip fractures were prior spine fracture (hazard ratio 7.3) and hip (hazard ratio 3.5). Prior rib fractures were associated with a 2.3-fold risk of subsequent vertebral fracture, previous upper leg fracture predicted a 2.2-fold increased risk of hip fracture; women with a history of ankle fracture were at 1.8-fold risk of future fracture of a weight-bearing bone. Our findings suggest that a broad range of prior fracture sites are associated with an increased risk of incident fractures, with important implications for clinical assessments and risk model development. PMID:22113888

  20. Radial electrical field effects in TJ-II. (Preliminary study)

    International Nuclear Information System (INIS)

    Guasp, J.

    1996-01-01

    The influence of the radial electric field upon the neoclassical transport coefficients of TJ-II helical axis Stellarator has been calculated as well on the microwave heating stage (ECRH) as on the neutral injection one (NBI). The influence of the solutions for the self-consistent ambipolar field on confinement times and temperatures has been studied by means of a zero-dimensional energy balance. The simultaneous presence of two roots, the electronic and the ionic one, is observed for the ECRH phase, while for NBI only the ionic root appears, although with a strong field intensity that could produce a favourable effect on confinement. The interest and need of the extension of these calculations to include radial profile effects by using spatial dependent transport codes in stressed

  1. Hamiltonian description of toroidal magnetic fields in vacuum

    International Nuclear Information System (INIS)

    Lewis, H.R.; Bates, J.W.

    1996-01-01

    An investigation of vacuum magnetic fields in toroidal geometry has been initiated. Previously, the general form of the magnetic scalar potential for fields regular at the poloidal axis was given. Here, these results have been expanded to obtain the magnetic scalar potential in a vacuum region that may surround a toroidal current distribution. Using this generalized magnetic scalar potential in conjunction with Boozer's canonical representation of a magnetic field, a field-line Hamiltonian for nonaxisymmetric vacuum fields has been derived. These fields axe being examined using a novel, open-quotes time-dependentclose quotes perturbation theory, which permits the iterative construction of invariants associated with magnetic field-line Hamiltonians that consist of an axisymmetric zeroth-order term, plus a nonaxisymmetric perturbation. By choosing appropriate independent variables, an explicit constructive procedure is developed which involves only a single canonical transformation. Such invariants are of interest because they provide a means of investigating the topology of magnetic field lines. Our objective is to elucidate the existence of magnetic surfaces for nonaxisymmetric vacuum configurations, as well as to provide an approach for studying the onset of stochastic behavior

  2. Context-dependent efficacy of a counter-conditioning strategy with atypical neuroleptic drugs in mice previously sensitized to cocaine.

    Science.gov (United States)

    Oliveira-Lima, A J; Marinho, Eav; Santos-Baldaia, R; Hollais, A W; Baldaia, M A; Talhati, F; Ribeiro, L T; Wuo-Silva, R; Berro, L F; Frussa-Filho, R

    2017-02-06

    We have previously demonstrated that treatment with ziprasidone and aripiprazole selectively inhibit the development of behavioral sensitization to cocaine in mice. We now investigate their effects on a counter-conditioning strategy in mice and the importance of the treatment environment for this phenomenon. Evaluate the context-specificity of ziprasidone and aripiprazole on conditioned locomotion to cocaine and cocaine-induced hyperlocomotion and behavioral sensitization in a counter-conditioning strategy in mice. Animals were sensitized with saline or cocaine injections in the open-field apparatus in a 15-day intermittent treatment and subsequently treated with vehicle, 5mg/kg ziprasidone or 0.1mg/kg aripiprazole paired to the open-field or the home-cage for 4 alternate days. Mice were then challenged with saline and cocaine in the open-field apparatus on subsequent days. While treatment with ziprasidone decreased spontaneous locomotion and conditioned locomotion alike, treatment with aripiprazole specifically attenuated the expression of conditioned hyperlocomotion to cocaine. Ziprasidone and aripiprazole had no effects on cocaine-induced conditioned hyperlocomotion observed during saline challenge after drug withdrawal. Treatment with either ziprasidone or aripiprazole when previously given in the cocaine-paired environment attenuated the subsequent expression of behavioral sensitization to cocaine. Animals treated with aripiprazole in the open-field, but not in the home-cage, showed a blunted response to cocaine when receiving a cocaine challenge for the first time. Both neuroleptic drugs showed a context-dependent effectiveness in attenuating long-term expression of cocaine-induced behavioral sensitization when administered in the cocaine-associated environment, with aripiprazole also showing effectiveness in blocking the expression of acute cocaine effects. Copyright © 2016. Published by Elsevier Inc.

  3. Field-reversed configuration translation studies in FRX-C/T

    International Nuclear Information System (INIS)

    Chrien, R.E.; Armstrong, W.T.; Klingner, P.L.; Linford, R.K.; McKenna, K.F.; Rej, D.J.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

    1984-01-01

    Field-Reversed Configuration (FRC) translation is being studied in the FRX-C/T device. The main goals of this experiment are to demonstrate translation into a dc field region with minimal losses and to study modification of the equilibrium profiles of the FRC by varying x/sub s/, the ratio of separatrix radius (r/sub s/) to conducting wall radius (r/sub w/), through translation. FRC's are formed with a range of densities (1→5 x 10/sup 15/ cm/sup -3/) and x/sub s/ (0.35→0.55) in the FRX-C source, configured as a slightly conical theta pinch coil (r/sub w/ increases from 0.22 m to 0.28 m in four steps over 2 m). In 10→40 μs after formation, the FRC enters a 0.20-m radius stainless steel vessel with a dc field up to 8 kG. The translation velocity varies from 5→12 cm/μs and is typically about one-half the FRC Alfven velocity

  4. Theoretical study on the laser-driven ion-beam trace probe in toroidal devices with large poloidal magnetic field

    Science.gov (United States)

    Yang, X.; Xiao, C.; Chen, Y.; Xu, T.; Yu, Y.; Xu, M.; Wang, L.; Wang, X.; Lin, C.

    2018-03-01

    Recently, a new diagnostic method, Laser-driven Ion-beam Trace Probe (LITP), has been proposed to reconstruct 2D profiles of the poloidal magnetic field (Bp) and radial electric field (Er) in the tokamak devices. A linear assumption and test particle model were used in those reconstructions. In some toroidal devices such as the spherical tokamak and the Reversal Field Pinch (RFP), Bp is not small enough to meet the linear assumption. In those cases, the error of reconstruction increases quickly when Bp is larger than 10% of the toroidal magnetic field (Bt), and the previous test particle model may cause large error in the tomography process. Here a nonlinear reconstruction method is proposed for those cases. Preliminary numerical results show that LITP could be applied not only in tokamak devices, but also in other toroidal devices, such as the spherical tokamak, RFP, etc.

  5. The CHAOS-4 geomagnetic field model

    DEFF Research Database (Denmark)

    Olsen, Nils; Lühr, H.; Finlay, Chris

    2014-01-01

    We present CHAOS-4, a new version in the CHAOS model series, which aims to describe the Earth's magnetic field with high spatial and temporal resolution. Terms up to spherical degree of at least n = 85 for the lithospheric field, and up to n = 16 for the time-varying core field are robustly...... to the core field, but the high-degree lithospheric field is regularized for n > 85. CHAOS-4 model is derived by merging two submodels: its low-degree part has been derived using similar model parametrization and data sets as used for previous CHAOS models (but of course including more recent data), while its...

  6. Advanced feedback control methods in EXTRAP T2R reversed field pinch

    International Nuclear Information System (INIS)

    Yadikin, D.; Brunsell, P. R.; Paccagnella, R.

    2006-01-01

    Previous experiments in the EXTRAP T2R reversed field pinch device have shown the possibility of suppression of multiple resistive wall modes (RWM). A feedback system has been installed in EXTRAP T2R having 100% coverage of the toroidal surface by the active coil array. Predictions based on theory and the previous experimental results show that the number of active coils should be sufficient for independent stabilization of all unstable RWMs in the EXTRAP T2R. Experiments using different feedback schemes are performed, comparing the intelligent shell, the fake rotating shell, and the mode control with complex feedback gains. Stabilization of all unstable RWMs throughout the discharge duration of t d ≅10τ w is seen using the intelligent shell feedback scheme. Mode rotation and the control of selected Fourier harmonics is obtained simultaneously using the mode control scheme with complex gains. Different sensor signals are studied. A feedback system with toroidal magnetic field sensors could have an advantage of lower feedback gain needed for the RWM suppression compared to the system with radial magnetic field sensors. In this study, RWM suppression is demonstrated, using also the toroidal field component as a sensor signal in the feedback system

  7. Advanced feedback control methods in EXTRAP T2R reversed field pinch

    Science.gov (United States)

    Yadikin, D.; Brunsell, P. R.; Paccagnella, R.

    2006-07-01

    Previous experiments in the EXTRAP T2R reversed field pinch device have shown the possibility of suppression of multiple resistive wall modes (RWM). A feedback system has been installed in EXTRAP T2R having 100% coverage of the toroidal surface by the active coil array. Predictions based on theory and the previous experimental results show that the number of active coils should be sufficient for independent stabilization of all unstable RWMs in the EXTRAP T2R. Experiments using different feedback schemes are performed, comparing the intelligent shell, the fake rotating shell, and the mode control with complex feedback gains. Stabilization of all unstable RWMs throughout the discharge duration of td≈10τw is seen using the intelligent shell feedback scheme. Mode rotation and the control of selected Fourier harmonics is obtained simultaneously using the mode control scheme with complex gains. Different sensor signals are studied. A feedback system with toroidal magnetic field sensors could have an advantage of lower feedback gain needed for the RWM suppression compared to the system with radial magnetic field sensors. In this study, RWM suppression is demonstrated, using also the toroidal field component as a sensor signal in the feedback system.

  8. Solar Polar Field Observed by SOHO/MDI and Hinode

    Science.gov (United States)

    Liu, Y.

    2009-12-01

    Using 1-minute cadence time-series full disk magnetograms taken by SOHO/MDI in 2007 March, and the corresponding Hinode/SOT vector magnetograms, I have studied evolutionary characteristics of magnetic elements in Sun's south polar region in solar minimum. It is found that the lifetime of magnetic elements is 17.0 hours on average with an average lifetime of 21.8 hours for elements with positive field, the dominant polarity in the south pole, and 1.6 hours for elements with negative field. The elements with positive field are dominant in the south pole with a percentage of 76% in element number and 90.5% in magnetic flux. The lifetime and magnetic flux of the elements is found to be highly related. This agrees with some previous studies for the elements in low latitude quiet regions. Using an image cross correlation method, I also measure solar rotation rate at high latitude, up to 85° in latitude, which is ω = 2.914-0.342 × sin2φ-0.482×sin4φ μrad/s sidereal. It agrees with previous studies using spectroscopic and image cross correlation methods, and also agrees with the results from some work using the element tracking method in which the sample of tracked elements is large. The consistency of those results from different data and methods strongly suggests that this rate at high latitude is reliable.

  9. Previous dropout from diabetic care as a predictor of patients' willingness to use mobile applications for self-management: A cross-sectional study.

    Science.gov (United States)

    Yamaguchi, Satoko; Waki, Kayo; Tomizawa, Nobuko; Waki, Hironori; Nannya, Yasuhito; Nangaku, Masaomi; Kadowaki, Takashi; Ohe, Kazuhiko

    2017-07-01

    Preventing dropout is crucial in managing diabetes. Accordingly, we investigated whether patients who had dropped out of diabetic care are suitable candidates for the use of mobile technologies - such as smartphone applications - to support self-management (mHealth), which might help prevent dropout. We carried out a cross-sectional study in Tokyo, Japan. Patients aged 20 years or older who were clinically diagnosed as diabetic and who regularly visited the outpatient unit at the University of Tokyo Hospital were recruited between August 2014 and March 2015. Data were collected through face-to-face structured interviews, physical measurements and medical records. Participants were asked whether they were willing to use mHealth after being shown DialBetics - an mHealth application for diabetics - as an example, and about their history of dropout and previous mHealth experience. Data were analyzed by multivariate logistic regression models. Of 307 patients with type 1 and type 2 diabetes, 34 (11.1%) had previously dropped out from diabetic care. Multivariate analysis identified previous mHealth experience as a negative predictor of dropout (odds ratio 0.211, P = 0.023). Of those 34 patients, 27 (79.4%) expressed willingness to use mHealth, a significantly higher percentage than for those who had never dropped out (51.5%, P = 0.002). After adjusting for confounders, history of dropout remained a strong predictor of willingness (odds ratio 3.870, P = 0.004). Patients who previously dropped out of diabetic care are suitable candidates for mHealth. Future studies must evaluate whether mHealth is effective for preventing repeated dropout and improving glycemic control among this population. © 2016 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

  10. Science and ecological literacy in undergraduate field studies education

    Science.gov (United States)

    Mapp, Kim J.

    There is an ever-increasing number of issues that face our world today; from climate change, water and food scarcity, to pollution and resource extraction. Science and ecology play fundamental roles in these problems, and yet the understanding of these fields is limited in our society (Miller, 2002; McBride, Brewer, Berkowitz, and Borrie, 2013). Across the nation students are finishing their undergraduate degrees and are expected to enter the workforce and society with the skills needed to succeed. The deficit of science and ecological literacy in these students has been recognized and a call for reform begun (D'Avanzo, 2003 and NRC, 2009). This mixed-methods study looked at how a field studies course could fill the gap of science and ecological literacy in undergraduates. Using grounded theory, five key themes were data-derived; definitions, systems thinking, human's role in the environment, impetus for change and transference. These themes where then triangulated for validity and reliability through qualitative and quantitative assessments. A sixth theme was also identified, the learning environment. Due to limited data to support this themes' development and reliability it is discussed in Chapter 5 to provide recommendations for further research. Key findings show that this field studies program influenced students' science and ecological literacy through educational theory and practice.

  11. Electric field controlled reversible magnetic anisotropy switching studied by spin rectification

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hengan; Fan, Xiaolong, E-mail: fanxiaolong@lzu.edu.cn; Wang, Fenglong; Jiang, Changjun; Rao, Jinwei; Zhao, Xiaobing; Xue, Desheng [Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Gui, Y. S.; Hu, C.-M. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada)

    2014-03-10

    In this letter, spin rectification was used to study the electric field controlled dynamic magnetic properties of the multiferroic composite which is a Co stripe with induced in-plane anisotropy deposited onto a Pb(Mg{sub 1∕3}Nb{sub 2∕3})O{sub 3}-PbTiO{sub 3} substrate. Due to the coupling between piezoelectric and magnetoelastic effects, a reversible in-plane anisotropy switching has been realized by varying the history of the applied electric field. This merit results from the electric hysteresis of the polarization in the nonlinear piezoelectric regime, which has been proved by a butterfly type electric field dependence of the in-plane anisotropy field. Moreover, the electric field dependent effective demagnetization field and linewidth have been observed at the same time.

  12. Effects of a Guide Field on the Larmor Electric Field and Upstream Electron Temperature Anisotropy in Collisionless Asymmetric Magnetic Reconnection

    Energy Technology Data Exchange (ETDEWEB)

    Ek-In, Surapat; Ruffolo, David [Department of Physics, Faculty of Science, Mahidol University, Bangkok (Thailand); Malakit, Kittipat [Department of Physics, Faculty of Science and Techonology, Thammasat University, Pathum Thani (Thailand); Shay, Michael A. [Department of Physics and Astronomy, University of Delaware, Newark, DE (United States); Cassak, Paul A., E-mail: kmalakit@gmail.com [Department of Physics and Astronomy, West Virginia University, Morgantown, WV (United States)

    2017-08-20

    We perform the first study of the properties of the Larmor electric field (LEF) in collisionless asymmetric magnetic reconnection in the presence of an out-of-plane (guide) magnetic field for different sets of representative upstream parameters at Earth’s dayside magnetopause with an ion temperature greater than the electron temperature (the ion-to-electron temperature ratio fixed at 2) using two-dimensional particle-in-cell simulations. We show that the LEF does persist in the presence of a guide field. We study how the LEF thickness and strength change as a function of guide field and the magnetospheric temperature and reconnecting magnetic field strength. We find that the thickness of the LEF structure decreases, while its magnitude increases when a guide field is added to the reconnecting magnetic field. The added guide field makes the Larmor radius smaller, so the scaling with the magnetospheric ion Larmor radius is similar to that reported for the case without a guide field. Note, however, that the physics causing the LEF is not well understood, so future work in other parameter regimes is needed to fully predict the LEF for arbitrary conditions. We also find that a previously reported upstream electron temperature anisotropy arises in the vicinity of the LEF region both with and without a guide field. We argue that the generation of the anisotropy is linked to the existence of the LEF. The LEF can be used in combination with the electron temperature anisotropy as a signature to effectively identify dayside reconnection sites in observations.

  13. Effects of a Guide Field on the Larmor Electric Field and Upstream Electron Temperature Anisotropy in Collisionless Asymmetric Magnetic Reconnection

    International Nuclear Information System (INIS)

    Ek-In, Surapat; Ruffolo, David; Malakit, Kittipat; Shay, Michael A.; Cassak, Paul A.

    2017-01-01

    We perform the first study of the properties of the Larmor electric field (LEF) in collisionless asymmetric magnetic reconnection in the presence of an out-of-plane (guide) magnetic field for different sets of representative upstream parameters at Earth’s dayside magnetopause with an ion temperature greater than the electron temperature (the ion-to-electron temperature ratio fixed at 2) using two-dimensional particle-in-cell simulations. We show that the LEF does persist in the presence of a guide field. We study how the LEF thickness and strength change as a function of guide field and the magnetospheric temperature and reconnecting magnetic field strength. We find that the thickness of the LEF structure decreases, while its magnitude increases when a guide field is added to the reconnecting magnetic field. The added guide field makes the Larmor radius smaller, so the scaling with the magnetospheric ion Larmor radius is similar to that reported for the case without a guide field. Note, however, that the physics causing the LEF is not well understood, so future work in other parameter regimes is needed to fully predict the LEF for arbitrary conditions. We also find that a previously reported upstream electron temperature anisotropy arises in the vicinity of the LEF region both with and without a guide field. We argue that the generation of the anisotropy is linked to the existence of the LEF. The LEF can be used in combination with the electron temperature anisotropy as a signature to effectively identify dayside reconnection sites in observations.

  14. Regularization and renormalization of quantum field theory in curved space-time

    International Nuclear Information System (INIS)

    Bernard, C.; Duncan, A.

    1977-01-01

    It is proposed that field theories quantized in a curved space-time manifold can be conveniently regularized and renormalized with the aid of Pauli-Villars regulator fields. The method avoids the conceptual difficulties of covariant point-separation approaches, by starting always from a manifestly generally covariant action, and the technical limitations of the dimensional reqularization approach, which requires solution of the theory in arbitrary dimension in order to go beyond a weak-field expansion. An action is constructed which renormalizes the weak-field perturbation theory of a massive scalar field in two space-time dimensions--it is shown that the trace anomaly previously found in dimensional regularization and some point-separation calculations also arises in perturbation theory when the theory is Pauli-Villars regulated. One then studies a specific solvable two-dimensional model of a massive scalar field in a Robertson-Walker asymptotically flat universe. It is shown that the action previously considered leads, in this model, to a well defined finite expectation value for the stress-energy tensor. The particle production (less than 0 in/vertical bar/theta/sup mu nu/(x,t)/vertical bar/0 in greater than for t → + infinity) is computed explicitly. Finally, the validity of weak-field perturbation theory (in the appropriate range of parameters) is checked directly in the solvable model, and the trace anomaly computed in the asymptotic regions t→ +- infinity independently of any weak field approximation. The extension of the model to higher dimensions and the renormalization of interacting (scalar) field theories are briefly discussed

  15. study of the magnetic field of the MGC-20 cyclotron accelerator magent

    International Nuclear Information System (INIS)

    Gad, K.M.M.

    2007-01-01

    studies of the magent of the MGC-20 cyclotron were carried out. measurements of the magnetic field were done in the cyclotron project, EAEA. calculations of the magnetic field were carried out using Poisson's 2D code, which was developed in Los Alamos laboratories in the USA. we developed a new calculation method for the magnetic field which is the independent layer method. a comparison between the measured and the calculated values for the magnetic field was done, we found good agreement between them, also we calculated the averaged magnetic field and found that the calculations show good isochronous magnetic field which is important in the focusing of the ion beam . study of the poisson code is presented as a target of the master plane to have a good understanding of the code as a step to develop the program or to do another one, this new calculation method proved to give good results for the magnetic field of a complicated magnet such as that of the MGC-20 magnet

  16. Study of field emission phenomena

    International Nuclear Information System (INIS)

    Ramanathan, Devaki; Vijendran, P.

    1976-01-01

    The theory of field emission has been explained, using Fowler-Nordheim equation and the Fowler-Nordheim plot. The imaging theory is also described in brief. The fabrication details of a field emission microscope (FEM) are mentioned. The design of the tube and the emitter assemblies are explained in detail. Simple experiments that can be demonstrated on the FEM such as indexing, detetermination of work function and surface diffusion constants, etc. are also mentioned. The use of FEM as a simple teaching aid has been brought out. (K.B.)

  17. An investigation into the induced electric fields from transcranial magnetic stimulation

    Science.gov (United States)

    Hadimani, Ravi; Lee, Erik; Duffy, Walter; Waris, Mohammed; Siddiqui, Waquar; Islam, Faisal; Rajamani, Mahesh; Nathan, Ryan; Jiles, David; David C Jiles Team; Walter Duffy Collaboration

    Transcranial magnetic stimulation (TMS) is a promising tool for noninvasive brain stimulation that has been approved by the FDA for the treatment of major depressive disorder. To stimulate the brain, TMS uses large, transient pulses of magnetic field to induce an electric field in the head. This transient magnetic field is large enough to cause the depolarization of cortical neurons and initiate a synaptic signal transmission. For this study, 50 unique head models were created from MRI images. Previous simulation studies have primarily used a single head model, and thus give a limited image of the induced electric field from TMS. This study uses finite element analysis simulations on 50 unique, heterogeneous head models to better investigate the relationship between TMS and the electric field induced in brain tissues. Results showed a significant variation in the strength of the induced electric field in the brain, which can be reasonably predicted by the distance from the TMS coil to the stimulated brain. Further, it was seen that some models had high electric field intensities in over five times as much brain volume as other models.

  18. Experimental and numerical study of the flow field around a small car

    Directory of Open Access Journals (Sweden)

    Dobrev Ivan

    2017-01-01

    Full Text Available This paper presents the aerodynamic study of a small car, which participated in Shell Ecomarathon Europe competition in the Urban Concept Hydrogen class. The goal is to understand the flow field around the vehicle. First, the flow is studied numerically using computational aerodynamics. The numerical simulation is carried out by means of CFD Fluent in order to obtain the drag force experienced by the vehicle and also the flow field. Then the flow field around the car is studied in a wind tunnel by means of particle image velocimetry (PIV. The comparison of the flow fields obtained numerically and experimentally shows good correspondence. The obtained results are very helpful for future car development and permit to improve the drag and to obtain a good stability.

  19. Particle-in-cell simulations of asymmetric guide-field reconnection: quadrupolar structure of Hall magnetic field

    Science.gov (United States)

    Schmitz, R. G.; Alves, M. V.; Barbosa, M. V. G.

    2017-12-01

    One of the most important processes that occurs in Earth's magnetosphere is known as magnetic reconnection (MR). This process can be symmetric or asymmetric, depending basically on the plasma density and magnetic field in both sides of the current sheet. A good example of symmetric reconnection in terrestrial magnetosphere occurs in the magnetotail, where these quantities are similar on the north and south lobes. In the dayside magnetopause MR is asymmetric, since the plasma regimes and magnetic fields of magnetosheath and magnetosphere are quite different. Symmetric reconnection has some unique signatures. For example, the formation of a quadrupolar structure of Hall magnetic field and a bipolar Hall electric field that points to the center of the current sheet. The different particle motions in the presence of asymmetries change these signatures, causing the quadrupolar pattern to be distorted and forming a bipolar structure. Also, the bipolar Hall electric field is modified and gives rise to a single peak pointing toward the magnetosheat, considering an example of magnetopause reconnection. The presence of a guide-field can also distort the quadrupolar pattern, by giving a shear angle across the current sheet and altering the symmetric patterns, according to previous simulations and observations. Recently, a quadrupolar structure was observed in an asymmetric guide-field MR event using MMS (Magnetospheric Multiscale) mission data [Peng et al., JGR, 2017]. This event shows clearly that the density asymmetry and the guide-field were not sufficient to form signatures of asymmetric reconnection. Using the particle-in-cell code iPIC3D [Markidis et al, Mathematics and Computers in Simulation, 2010] with the MMS data from this event used to define input parameters, we found a quadrupolar structure of Hall magnetic field and a bipolar pattern of Hall electric field in ion scales, showing that our results are in an excellent agreement with the MMS observations. To our

  20. A time-averaged regional model of the Hermean magnetic field

    Science.gov (United States)

    Thébault, E.; Langlais, B.; Oliveira, J. S.; Amit, H.; Leclercq, L.

    2018-03-01

    This paper presents the first regional model of the magnetic field of Mercury developed with mathematical continuous functions. The model has a horizontal spatial resolution of about 830 km at the surface of the planet, and it is derived without any a priori information about the geometry of the internal and external fields or regularization. It relies on an extensive dataset of the MESSENGER's measurements selected over its entire orbital lifetime between 2011 and 2015. A first order separation between the internal and the external fields over the Northern hemisphere is achieved under the assumption that the magnetic field measurements are acquired in a source free region within the magnetospheric cavity. When downward continued to the core-mantle boundary, the model confirms some of the general structures observed in previous studies such as the dominance of zonal field, the location of the North magnetic pole, and the global absence of significant small scale structures. The transformation of the regional model into a global spherical harmonic one provides an estimate for the axial quadrupole to axial dipole ratio of about g20/g10 = 0.27 . This is much lower than previous estimates of about 0.40. We note that it is possible to obtain a similar ratio provided that more weight is put on the location of the magnetic equator and less elsewhere.

  1. Boundaries immersed in a scalar quantum field

    International Nuclear Information System (INIS)

    Actor, A.A.; Bender, I.

    1996-01-01

    We study the interaction between a scalar quantum field φ(x), and many different boundary configurations constructed from (parallel and orthogonal) thin planar surfaces on which φ(x) is constrained to vanish, or to satisfy Neumann conditions. For most of these boundaries the Casimir problem has not previously been investigated. We calculate the canonical and improved vacuum stress tensors left angle T μv (x) right angle and left angle direct difference μv (x) right angle of φ(x) for each example. From these we obtain the local Casimir forces on all boundary planes. For massless fields, both vacuum stress tensors yield identical attractive local Casimir forces in all Dirichlet examples considered. This desirable outcome is not a priori obvious, given the quite different features of left angle T μv (x) right angle and left angle direct difference μv (x) right angle. For Neumann conditions, left angle T μv (x) right angle and left angle direct difference μv (x) right angle lead to attractive Casimir stresses which are not always the same. We also consider Dirichlet and Neumann boundaries immersed in a common scalar quantum field, and find that these repel. The extensive catalogue of worked examples presented here belongs to a large class of completely solvable Casimir problems. Casimir forces previously unknown are predicted, among them ones which might be measurable. (orig.)

  2. Study of the performance of Micromegas detectors in magnetic field

    Directory of Open Access Journals (Sweden)

    Dimitrios Sampsonidis

    2018-01-01

    Full Text Available Resistive Micromegas (MICRO MEsh GAseous Structure detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW, will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10×10 cm2 in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability of the chambers to provide unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity as a function of the magnetic field are presented and both are compared to expectations based on Garfield-Magboltz simulations. Several methods to correct the position bias are applied, based on the chamber configuration or on the knowledge of the local value of the magnetic field. The results of these studies are presented together with an overall discussion of the Micromegas tracking capability in magnetic field.

  3. Study of the performance of Micromegas detectors in magnetic field

    Science.gov (United States)

    Dimitrios, Sampsonidis

    2018-02-01

    Resistive Micromegas (MICRO MEsh GAseous Structure) detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW), will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10×10 cm2) in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability of the chambers to provide unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity as a function of the magnetic field are presented and both are compared to expectations based on Garfield-Magboltz simulations. Several methods to correct the position bias are applied, based on the chamber configuration or on the knowledge of the local value of the magnetic field. The results of these studies are presented together with an overall discussion of the Micromegas tracking capability in magnetic field.

  4. Shape and fission instabilities of ferrofluids in non-uniform magnetic fields

    Science.gov (United States)

    Vieu, Thibault; Walter, Clément

    2018-04-01

    We study static distributions of ferrofluid submitted to non-uniform magnetic fields. We show how the normal-field instability is modified in the presence of a weak magnetic field gradient. Then we consider a ferrofluid droplet and show how the gradient affects its shape. A rich phase transitions phenomenology is found. We also investigate the creation of droplets by successive splits when a magnet is vertically approached from below and derive theoretical expressions which are solved numerically to obtain the number of droplets and their aspect ratio as function of the field configuration. A quantitative comparison is performed with previous experimental results, as well as with our own experiments, and yields good agreement with the theoretical modeling.

  5. Previous utilization of service does not improve timely booking in ...

    African Journals Online (AJOL)

    Previous utilization of service does not improve timely booking in antenatal care: Cross sectional study ... Journal Home > Vol 24, No 3 (2010) > ... Results: Past experience on antenatal care service utilization did not come out as a predictor for ...

  6. Planning and setting objectives in field studies: Chapter 2

    Science.gov (United States)

    Fisher, Robert N.; Dodd, C. Kenneth

    2016-01-01

    This chapter enumerates the steps required in designing and planning field studies on the ecology and conservation of reptiles, as these involve a high level of uncertainty and risk. To this end, the chapter differentiates between goals (descriptions of what one intends to accomplish) and objectives (the measurable steps required to achieve the established goals). Thus, meeting a specific goal may require many objectives. It may not be possible to define some of them until certain experiments have been conducted; often evaluations of sampling protocols are needed to increase certainty in the biological results. And if sampling locations are fixed and sampling events are repeated over time, then both study-specific covariates and sampling-specific covariates should exist. Additionally, other critical design considerations for field study include obtaining permits, as well as researching ethics and biosecurity issues.

  7. Impact of previously disadvantaged land-users on sustainable ...

    African Journals Online (AJOL)

    Impact of previously disadvantaged land-users on sustainable agricultural ... about previously disadvantaged land users involved in communal farming systems ... of input, capital, marketing, information and land use planning, with effect on ...

  8. A statistical study of high-altitude electric fields measured on the Viking satellite

    International Nuclear Information System (INIS)

    Lindqvist, P.A.; Marklund, G.T.

    1990-01-01

    Characteristics of high-altitude data from the Viking electric field instrument are presented in a statistical study based on 109 Viking orbits. The study is focused in particular on the signatures of and relationships between various parameters measured by the electric field instrument, such as the parallel and transverse (to B) components of the electric field instrument, such as electric field variability. A major goal of the Viking mission was to investigate the occurrence and properties of parallel electric fields and their role in the auroral acceleration process. The results in this paper on the altitude distribution of the electric field variability confirm earlier findings on the distribution of small-scale electric fields and indicate the presence of parallel fields up to about 11,000 km altitude. The directly measured parallel electric field is also investigated in some detail. It is in general directed upward with an average value of 1 mV/m, but depends on, for example, altitude and plasma density. Possible sources of error in the measurement of the parallel field are also considered and accounted for

  9. Field studies into the dynamics of product development tasks

    NARCIS (Netherlands)

    Oorschot, van K.E.; Bertrand, J.W.M.; Rutte, C.G.

    2005-01-01

    Purpose – This paper aims to describe three exploratory field studies investigating which characteristics add to later time to market and/or low product functionality of newly developed products. The studies are conducted at the level of developments tasks, or work packages. The first and second

  10. Holding molecular dications together in strong laser fields

    International Nuclear Information System (INIS)

    Guo Chunlei

    2006-01-01

    Metastable channel of doubly ionized carbon monoxide, CO 2+ , was scantly seen in previous strong-field experiments at the visible wavelength region, but was commonly observed using single high-energy photon or electron excitation. For the first time with near-IR ultrashort-pulse radiation, we observe an abundance of CO 2+ . We show that CO 2+ results from nonsequential double ionization, while its dissociation counterpart, C + +O + , results from sequential processes, and CO 2+ can be obtained through either single high-energy photon or electron excitation or multiphoton ionization with ultrashort pulses before a critical internuclear distance is reached. Our study demonstrates the experimental conditions to converge the outcomes from two vastly different regimes, namely, multiphoton excitation and ionization in strong fields and single high-energy photon or electron excitation and ionization in weak fields

  11. Comparing search patterns in digital breast tomosynthesis and full-field digital mammography: an eye tracking study.

    Science.gov (United States)

    Aizenman, Avi; Drew, Trafton; Ehinger, Krista A; Georgian-Smith, Dianne; Wolfe, Jeremy M

    2017-10-01

    As a promising imaging modality, digital breast tomosynthesis (DBT) leads to better diagnostic performance than traditional full-field digital mammograms (FFDM) alone. DBT allows different planes of the breast to be visualized, reducing occlusion from overlapping tissue. Although DBT is gaining popularity, best practices for search strategies in this medium are unclear. Eye tracking allowed us to describe search patterns adopted by radiologists searching DBT and FFDM images. Eleven radiologists examined eight DBT and FFDM cases. Observers marked suspicious masses with mouse clicks. Eye position was recorded at 1000 Hz and was coregistered with slice/depth plane as the radiologist scrolled through the DBT images, allowing a 3-D representation of eye position. Hit rate for masses was higher for tomography cases than 2-D cases and DBT led to lower false positive rates. However, search duration was much longer for DBT cases than FFDM. DBT was associated with longer fixations but similar saccadic amplitude compared with FFDM. When comparing radiologists' eye movements to a previous study, which tracked eye movements as radiologists read chest CT, we found DBT viewers did not align with previously identified "driller" or "scanner" strategies, although their search strategy most closely aligns with a type of vigorous drilling strategy.

  12. Theoretical study of in-plane response of magnetic field sensor to magnetic beads in an in-plane homogeneous field

    DEFF Research Database (Denmark)

    Damsgaard, Christian Danvad; Hansen, Mikkel Fougt

    2008-01-01

    We present a systematic theoretical study of the average in-plane magnetic field on square and rectangular magnetic field sensors from a single magnetic bead and a monolayer of magnetic beads magnetized by an in-plane externally applied homogeneous magnetic field. General theoretical expressions...... are derived such that the sensor response and its dependence on the sensor size, spacer layer thickness, bead diameter, and bead susceptibility can easily be evaluated. The average magnetic field from a single bead close to the sensor shows a strong dependence on the position of the bead and a change of sign...... when the bead passes the edge of the sensor in the direction of the applied field. Analytical approximations are derived for the average field from a homogeneous monolayer of beads for beads much smaller than the sensor dimension and for a bead size chosen to minimize the position sensitivity...

  13. Response to deep TMS in depressive patients with previous electroconvulsive treatment.

    Science.gov (United States)

    Rosenberg, Oded; Zangen, Abraham; Stryjer, Rafael; Kotler, Moshe; Dannon, Pinhas N

    2010-10-01

    The efficacy of transcranial magnetic stimulation (TMS) in the treatment of major depression has already been shown. Novel TMS coils allowing stimulation of deeper brain regions have recently been developed and studied. Our study is aimed at exploring the possible efficacy of deep TMS in patients with resistant depression, who previously underwent electroconvalsive therapy (ECT). Using Brainsway's deep TMS H1 coil, six patients who previously underwent ECT, were treated with 120% power of the motor threshold at a frequency of 20 Hz. Patients underwent five sessions per week, up to 4 weeks. Before the study, patients were evaluated using the Hamilton depression rating scale (HDRS, 24 items), the Hamilton anxiety scale, and the Beck depression inventory and were again evaluated after 5, 10, 15, and 20 daily treatments. Response to treatment was considered a reduction in the HDRS of at least 50%, and remission was considered a reduction of the HDRS-24 below 10 points. Two of six patients responded to the treatment with deep TMS, including one who achieved full remission. Our results suggest the possibility of a subpopulation of depressed patients who may benefit from deep TMS treatment, including patients who did not respond to ECT previously. However, the power of the study is small and similar larger samples are needed. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. The significance of field work in monographic studies

    Science.gov (United States)

    The focus of this paper is to document the clear and obvious advantages of field work for monographic studies. These advantages include: 1) ability to understand published distributions better and greatly expand these data, 2) access to taxonomic data obscured on herbarium sheets (as colors, odors, ...

  15. Transition from Fowler-Nordheim field emission to space charge limited current density

    International Nuclear Information System (INIS)

    Feng, Y.; Verboncoeur, J. P.

    2006-01-01

    The Fowler-Nordheim law gives the current density extracted from a surface under strong fields, by treating the emission of electrons from a metal-vacuum interface in the presence of an electric field normal to the surface as a quantum mechanical tunneling process. Child's law predicts the maximum transmitted current density by considering the space charge effect. When the electric field becomes high enough, the emitted current density will be limited by Child's law. This work analyzes the transition of the transmitted current density from the Fowler-Nordheim law to Child's law space charge limit using a one-dimensional particle-in-cell code. Also studied is the response of the emission model to strong electric fields near the transition point. We find the transition without geometrical effort is smooth and much slower than reported previously [J. P. Barbour, W. W. Dolan, J. K. Trolan, E. E. Martin, and W. P. Dyke, Phys. Rev. 92, 45 (1953)]. We analyze the effects of geometric field enhancement and work function on the transition. Using our previous model for effective field enhancement [Y. Feng and J. P. Verboncoeur, Phys. Plasmas 12, 103301 (2005)], we find the geometric effect dominates, and enhancement β>10 can accelerate the approach to the space charge limit at practical electric field. A damped oscillation near the local plasma frequency is observed in the transient system response

  16. Volcanic Hazard Education through Virtual Field studies of Vesuvius and Laki Volcanoes

    Science.gov (United States)

    Carey, S.; Sigurdsson, H.

    2011-12-01

    Volcanic eruptions pose significant hazards to human populations and have the potential to cause significant economic impacts as shown by the recent ash-producing eruptions in Iceland. Demonstrating both the local and global impact of eruptions is important for developing an appreciation of the scale of hazards associated with volcanic activity. In order to address this need, Web-based virtual field exercises at Vesuvius volcano in Italy and Laki volcano in Iceland have been developed as curriculum enhancements for undergraduate geology classes. The exercises are built upon previous research by the authors dealing with the 79 AD explosive eruption of Vesuvius and the 1783 lava flow eruption of Laki. Quicktime virtual reality images (QTVR), video clips, user-controlled Flash animations and interactive measurement tools are used to allow students to explore archeological and geological sites, collect field data in an electronic field notebook, and construct hypotheses about the impacts of the eruptions on the local and global environment. The QTVR images provide 360o views of key sites where students can observe volcanic deposits and formations in the context of a defined field area. Video sequences from recent explosive and effusive eruptions of Carribean and Hawaiian volcanoes are used to illustrate specific styles of eruptive activity, such as ash fallout, pyroclastic flows and surges, lava flows and their effects on the surrounding environment. The exercises use an inquiry-based approach to build critical relationships between volcanic processes and the deposits that they produce in the geologic record. A primary objective of the exercises is to simulate the role of a field volcanologist who collects information from the field and reconstructs the sequence of eruptive processes based on specific features of the deposits. Testing of the Vesuvius and Laki exercises in undergraduate classes from a broad spectrum of educational institutions shows a preference for the

  17. Determining root correspondence between previously and newly detected objects

    Science.gov (United States)

    Paglieroni, David W.; Beer, N Reginald

    2014-06-17

    A system that applies attribute and topology based change detection to networks of objects that were detected on previous scans of a structure, roadway, or area of interest. The attributes capture properties or characteristics of the previously detected objects, such as location, time of detection, size, elongation, orientation, etc. The topology of the network of previously detected objects is maintained in a constellation database that stores attributes of previously detected objects and implicitly captures the geometrical structure of the network. A change detection system detects change by comparing the attributes and topology of new objects detected on the latest scan to the constellation database of previously detected objects.

  18. Autonomous dynamic obstacle avoidance for bacteria-powered microrobots (BPMs) with modified vector field histogram.

    Science.gov (United States)

    Kim, Hoyeon; Cheang, U Kei; Kim, Min Jun

    2017-01-01

    In order to broaden the use of microrobots in practical fields, autonomous control algorithms such as obstacle avoidance must be further developed. However, most previous studies of microrobots used manual motion control to navigate past tight spaces and obstacles while very few studies demonstrated the use of autonomous motion. In this paper, we demonstrated a dynamic obstacle avoidance algorithm for bacteria-powered microrobots (BPMs) using electric field in fluidic environments. A BPM consists of an artificial body, which is made of SU-8, and a high dense layer of harnessed bacteria. BPMs can be controlled using externally applied electric fields due to the electrokinetic property of bacteria. For developing dynamic obstacle avoidance for BPMs, a kinematic model of BPMs was utilized to prevent collision and a finite element model was used to characteristic the deformation of an electric field near the obstacle walls. In order to avoid fast moving obstacles, we modified our previously static obstacle avoidance approach using a modified vector field histogram (VFH) method. To validate the advanced algorithm in experiments, magnetically controlled moving obstacles were used to intercept the BPMs as the BPMs move from the initial position to final position. The algorithm was able to successfully guide the BPMs to reach their respective goal positions while avoiding the dynamic obstacles.

  19. Ten years later: Evaluation of the effectiveness of 12.5% amitraz against a field population of Rhipicephalus (Boophilus) microplus using field studies, artificial infestation (Stall tests) and adult immersion tests.

    Science.gov (United States)

    Maciel, Willian Giquelin; Lopes, Welber Daniel Zanetti; Cruz, Breno Cayeiro; Gomes, Lucas Vinicius Costa; Teixeira, Weslen Fabrício Pires; Buzzulini, Carolina; Bichuette, Murilo Abud; Campos, Gabriel Pimentel; Felippelli, Gustavo; Soares, Vando Edésio; de Oliveira, Gilson Pereira; da Costa, Alvimar José

    2015-12-15

    Using field trials, artificial infestations (Stall tests) and in vitro adult immersion tests, the present study evaluated the acaricidal efficacy of 12.5% amitraz administered via whole body spraying against a Rhipicephalus (Boophilus) microplus population that did not have any contact with chemical products belonging to this acaricide family for 10 years (approximately 40 generations). Two natural infestation trials, two artificial infestation trials (Stall tests) and two adult immersion tests were performed in two different stages in 2005 and 2015. Between 2002 and 2015, the bovine herd of this property was formed by approximately 450 animals from the Simmental breed that were divided into nine paddocks formed by Cynodon dactylon (L.) Pers. For the natural infestation experiments in 2005 and 2015, we selected nearly 70 animals naturally infested with ticks from the same herd that belonged to the "São Paulo" farm located in São José do Rio Pardo, São Paulo, Brazil. Field studies were performed in the same paddock (9). To evaluate anti-R. (B.) microplus activity in the artificially infested cattle (Stall tests) and adult immersion tests, two experiments of each methodology were performed at CPPAR (the Center of Research in Animal Health located on the FCAV/UNESP campus in Jaboticabal, São Paulo, Brazil) in 2005 and 2015. R. (B.) microplus used in the artificial infestation, and adult immersion test experiments were obtained from paddocks 1-9 in 2005 and 2015 from the commercial farm where the field studies were performed. Based on the obtained results, it was possible to conclude that amitraz use in rotation with pyrethroids every 28 days for three consecutive years (2002-2004) previous to the beginning of the first trial (2005) was sufficient to generate a R. (B.) microplus strain resistant to amitraz. Moreover, using field trials, artificial infestations (Stall tests) and adult immersion tests, we verified that 40 generations of the tick species with no

  20. Maximizing research study effectiveness in malaria elimination settings: a mixed methods study to capture the experiences of field-based staff.

    Science.gov (United States)

    Canavati, Sara E; Quintero, Cesia E; Haller, Britt; Lek, Dysoley; Yok, Sovann; Richards, Jack S; Whittaker, Maxine Anne

    2017-09-11

    In a drug-resistant, malaria elimination setting like Western Cambodia, field research is essential for the development of novel anti-malarial regimens and the public health solutions necessary to monitor the spread of resistance and eliminate infection. Such field studies often face a variety of similar implementation challenges, but these are rarely captured in a systematic way or used to optimize future study designs that might overcome similar challenges. Field-based research staff often have extensive experience and can provide valuable insight regarding these issues, but their perspectives and experiences are rarely documented and seldom integrated into future research protocols. This mixed-methods analysis sought to gain an understanding of the daily challenges encountered by research field staff in the artemisinin-resistant, malaria elimination setting of Western Cambodia. In doing so, this study seeks to understand how the experiences and opinions of field staff can be captured, and used to inform future study designs. Twenty-two reports from six field-based malaria studies conducted in Western Cambodia were reviewed using content analysis to identify challenges to conducting the research. Informal Interviews, Focus Group Discussions and In-depth Interviews were also conducted among field research staff. Thematic analysis of the data was undertaken using Nvivo 9 ® software. Triangulation and critical case analysis was also used. There was a lack of formalized avenues through which field workers could report challenges experienced when conducting the malaria studies. Field research staff faced significant logistical barriers to participant recruitment and data collection, including a lack of available transportation to cover long distances, and the fact that mobile and migrant populations (MMPs) are usually excluded from studies because of challenges in follow-up. Cultural barriers to communication also hindered participant recruitment and created

  1. Treatment satisfaction with paliperidone extended-release tablets: open-label study in schizophrenia patients dissatisfied with previous antipsychotic medication

    Directory of Open Access Journals (Sweden)

    Yang FD

    2017-04-01

    Full Text Available Fu De Yang,1 Juan Li,1 Yun Long Tan,1 Wei Ye Liang,1 Rongzhen Zhang,1 Ning Wang,1 Wei Feng,1 Shangli Cai,2 Jian Min Zhuo,2 Li Li Zhang2 1Beijing Hui-Long-Guan Hospital, 2Department of Medical Affairs, Xian Janssen Pharmaceutical Ltd, Beijing, People’s Republic of China Objective: The aim of this study was to evaluate the changes in treatment satisfaction after switching to paliperidone extended-release (ER in Chinese schizophrenia patients dissatisfied with their previous antipsychotic treatment.Methods: In this 8-week, open-label, single-arm, multicenter, prospective study, 1,693 patients dissatisfied with previous antipsychotic medication were enrolled and switched to paliperidone ER tablets (3–12 mg/d based on clinical judgment. The primary efficacy end point was change in Medication Satisfaction Questionnaire (MSQ score from baseline to week 8. The secondary end points included percentage of patients with MSQ score ≥4, as well as changes in Clinical Global Improvement-Severity (CGI-S and Personal and Social Performance (PSP scores.Results: MSQ scores increased significantly from baseline (mean [standard deviation {SD}]: 2.48 [0.55] to week 8 (5.47 [0.89], P<0.0001; primary end point, full analysis set. The percentage of patients with MSQ score ≥4 was 95.9% at week 8, indicating that most of the patients were satisfied with their treatment. Significant (P<0.0001 improvements from baseline to week 8 were noted in CGI-S score (2.37 [1.20] and PSP score (25.5 [15.0]. A total of 174 (10.28% patients experienced adverse events (AEs. The most common (>10 patients events were extrapyramidal disorder (n=84, 4.96%, poor quality sleep (n=18, 1.06% and akathisia (n=13, 0.77%. The majority of AEs were mild to moderate in severity. No deaths occurred.Conclusion: Treatment satisfaction improved after switching to paliperidone ER from the previous antipsychotic in Chinese patients with schizophrenia. Keywords: atypical antipsychotics, open label

  2. Some design aspects of transuranic field studies

    International Nuclear Information System (INIS)

    Gilbert, R.O.; Eberhardt, L.L.

    1977-01-01

    In this paper, we discuss some design aspects of transuranic field studies. Some of the principal steps in the design of such studies are given and illustrated using examples. This is followed by a review of sampling designs that have been used at nuclear detonation and safety-shot sites on the Nevada Test Site and elsewhere for estimating spatial pattern and total amounts in soil. Some design aspects of ecosystem-type transuranic studies for estimating total amounts as well as movement of transuranics between ecosystem components are also discussed. Acceptance sampling using either attributes or measurements is considered as a possible approach for deciding whether to clean up a contaminated site. Three general guidelines for the design of efficient transuranic studies are presented

  3. Numerical studies of gauge field theories

    International Nuclear Information System (INIS)

    Creutz, M.

    1981-06-01

    Monte Carlo simulation of statistical systems is a well established technique of the condensed matter physicist. In the last few years, particle theorists have rediscovered this method and are having a marvelous time applying it to quantized gauge field theories. The main result has been strong numerical evidence that the standard SU(3) non-Abelian gauge theory of the strong interaction is capable of simultaneously confining quarks into the physical hadrons and exhibiting asymptotic freedom, the phenomenon of quark interactions being small at short distances. In four dimensions, confinement is a non-perturbative phenomenon. Essentially all models of confinement tie widely separated quarks together with strings of gauge field flux. This gives rise to a linear potential at long distances. A Monte Carlo program generates a sequence of field configuration by a series of random changes of the fields. The algorithm is so constructed that ultimately the probability density for finding any given configuration is proportional to the Boltzmann weighting. We bring our lattices into thermal equilibrium with a heat bath at a temperature specified by the coupling constant. Thus we do computer experiments with four-dimensional crystals stored in a computer memory. As the entire field configuration is stored, we have access to any correlation function desired. These lectures describe the kinds of experiments being done and the implications of these results for strong interaction physics

  4. Culture Studies in the Field of International Business Research

    DEFF Research Database (Denmark)

    Worm, Verner; Li, Xin; Jakobsen, Michael

    Purpose: The purpose of this paper is to describe the status of culture studies within the field of international business research, and to examine how two main paradigms – essentialism and social constructivism – relate to the discourse in this field. We analyze the main points of the two...... in this paper. Practical implications: We encourage practitioners to learn how to switch, both sequentially and spatially, between the two paradigms of culture (fundamentally incommensurable though they are). This involves taking a “both/or” approach to the two paradigms. Originality/Value: We show...

  5. Particular features of conditioned electrodefensive reflex in white rats on background of constant magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Shust, I.V.; Galantyuk, S.I.; Cheretyanko, Yu.V.

    Study of the influence of magnetic fields upon the higher nervous activity of man and animals has long been attracting the attention of researchers. It is indicated in the literature that magnetic fields inhibit development of conditioned reflexes in planarians, fishes, and mammals. However, there are data of opposite nature as well, indicating accelerated development of the avoidance reflex in animals exposed previously to a magnetic field. Researchers studied formation of a conditioned electrodefensive reflex (CER) in white rats exposed to a constant magnetic field (CMF), and the influence of a vitamin preparation - galascorbin - on formation of the CER in animals exposed to a CMF.

  6. Hielke is a Bayesian, balancing field robot

    NARCIS (Netherlands)

    Evert, van F.K.; Lamaker, E.J.J.; Polder, G.; Jong, de A.; Heijden, van der G.W.A.M.; Groendijk, E.J.K.; Lotz, L.A.P.; Zalm, van der A.J.A.

    2008-01-01

    Driven by the success of the previous events in Wageningen in 2003, 2004 and 2005 and the Field Robot Event hosted by Hohenheim University in Stuttgart, Germany in 2006, Wageningen University organized the 5th Field Robot Event on June 14-16, 2007. This event was accompanied by a workshop and a fair

  7. Statistical Study of the Magnetic Field Orientation in Solar Filaments

    Science.gov (United States)

    Hanaoka, Yoichiro; Sakurai, Takashi

    2017-12-01

    We have carried out a statistical study of the average orientation of the magnetic field in solar filaments with respect to their axes for more than 400 samples, based on data taken with daily full-Sun, full-Stokes spectropolarimetric observations using the He I 1083.0 nm line. The major part of the samples are the filaments in the quiet areas, but those in the active areas are included as well. The average orientation of the magnetic field in filaments shows a systematic property depending on the hemisphere; the direction of the magnetic field in filaments in the northern (southern) hemisphere mostly deviates clockwise (counterclockwise) from their axes, which run along the magnetic polarity inversion line. The deviation angles of the magnetic field from the axes are concentrated between 10° and 30°. This hemispheric pattern is consistent with that revealed for chirality of filament barbs, filament channels, and for other solar features found to possess chirality. For some filaments, it was confirmed that their magnetic field direction is locally parallel to their structure seen in Hα images. Our results for the first time confirmed this hemispheric pattern with the direct observation of the magnetic field in filaments. Interestingly, the filaments which show the opposite magnetic field deviation to the hemispheric pattern, are in many cases found above the polarity inversion line whose ambient photospheric magnetic field has the polarity alignment being opposite to that of active regions following the Hale–Nicholson law.

  8. Correlation of gene expression and contaminat concentrations in wild largescale suckers: a field-based study

    Science.gov (United States)

    Christiansen, Helena E.; Mehinto, Alvine C.; Yu, Fahong; Perry, Russell W.; Denslow, Nancy D.; Maule, Alec G.; Mesa, Matthew G.

    2014-01-01

    Toxic compounds such as organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ether flame retardants (PBDEs) have been detected in fish, birds, and aquatic mammals that live in the Columbia River or use food resources from within the river. We developed a custom microarray for largescale suckers (Catostomus macrocheilus) and used it to investigate the molecular effects of contaminant exposure on wild fish in the Columbia River. Using Significance Analysis of Microarrays (SAM) we identified 72 probes representing 69 unique genes with expression patterns that correlated with hepatic tissue levels of OCs, PCBs, or PBDEs. These genes were involved in many biological processes previously shown to respond to contaminant exposure, including drug and lipid metabolism, apoptosis, cellular transport, oxidative stress, and cellular chaperone function. The relation between gene expression and contaminant concentration suggests that these genes may respond to environmental contaminant exposure and are promising candidates for further field and laboratory studies to develop biomarkers for monitoring exposure of wild fish to contaminant mixtures found in the Columbia River Basin. The array developed in this study could also be a useful tool for studies involving endangered sucker species and other sucker species used in contaminant research.

  9. Phase field model for the study of boiling

    International Nuclear Information System (INIS)

    Ruyer, P.

    2006-07-01

    This study concerns both the modeling and the numerical simulation of boiling flows. First we propose a review concerning nucleate boiling at high wall heat flux and focus more particularly on the current understanding of the boiling crisis. From this analysis we deduce a motivation for the numerical simulation of bubble growth dynamics. The main and remaining part of this study is then devoted to the development and analyze of a phase field model for the liquid-vapor flows with phase change. We propose a thermodynamic quasi-compressible formulation whose properties match the one required for the numerical study envisaged. The system of governing equations is a thermodynamically consistent regularization of the sharp interface model, that is the advantage of the di use interface models. We show that the thickness of the interface transition layer can be defined independently from the thermodynamic description of the bulk phases, a property that is numerically attractive. We derive the kinetic relation that allows to analyze the consequences of the phase field formulation on the model of the dissipative mechanisms. Finally we study the numerical resolution of the model with the help of simulations of phase transition in simple configurations as well as of isothermal bubble dynamics. (author)

  10. Experimental study of induced staggered magnetic fields in dysprosium gallium garnet (DGG)

    International Nuclear Information System (INIS)

    Steiner, M.; Corliss, L.M.; Hastings, J.M.; Blume, M.; Giordano, N.; Wolf, W.P.

    1979-01-01

    Neutron diffraction techniques have been used to study induced staggered magnetic field effects in DGG. The application of a uniform magnetic field at temperatures much greater than the Neel temperature induces a significant amount of antiferromagnetic order. The temperature and field dependences of this effect are in good agreement with recent theoretical predicions

  11. Introducing time-dependent molecular fields: a new derivation of the wave equations

    Science.gov (United States)

    Baer, Michael

    2018-02-01

    This article is part of a series of articles trying to establish the concept molecular field. The theory that induced us to introduce this novel concept is based on the Born-Huang expansion as applied to the Schroedinger equation that describes the interaction of a molecular system with an external electric field. Assuming the molecular system is made up of two coupled adiabatic states the theory leads from a single spatial curl equation, two space-time curl equations and one single space-time divergent equation to a pair of decoupled wave equations usually encountered within the theory of fields. In the present study, just like in the previous study [see Baer et al., Mol. Phys. 114, 227 (2016)] the wave equations are derived for an electric field having two features: (a) its intensity is high enough; (b) its duration is short enough. Although not all the findings are new the derivation, in the present case, is new, straightforward, fluent and much friendlier as compared to the previous one and therefore should be presented again. For this situation the study reveals that the just described interaction creates two fields that coexist within a molecule: one is a novel vectorial field formed via the interaction of the electric field with the Born-Huang non-adiabatic coupling terms (NACTs) and the other is an ordinary, scalar, electric field essentially identical to the original electric field. Section 4 devoted to the visualization of the outcomes via two intersecting Jahn-Teller cones which contain NACTs that become singular at the intersection point of these cones. Finally, the fact that eventually we are facing a kind of a cosmic situation may bring us to speculate that singular NACTs are a result of cosmic phenomena. Thus, if indeed this singularity is somehow connected to reality then, like other singularities in physics, it is formed at (or immediately after) the Big Bang and consequently, guarantees the formation of molecules.

  12. Rovibrational dynamics of the RbCs molecule in static electric fields. Classical study

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, Pedro F.; Iñarrea, Manuel [Área de Física, Universidad de la Rioja, E-26006 Logroño (Spain); Salas, J. Pablo, E-mail: josepablo.salas@unirioja.es [Área de Física, Universidad de la Rioja, E-26006 Logroño (Spain)

    2012-04-02

    We study the classical dynamics of the RbCs molecule in the presence of a static electric field. Under the Born–Oppenheimer approximation, we perform a rovibrational investigation which includes the interaction of the field with the molecular polarizability. The stability of the equilibrium points and the phase space structure of the system are explored in detail. We find that, for strong electric fields or for energies close to the dissociation threshold, the molecular polarizability causes relevant effects on the system dynamics. -- Highlights: ► We study the classical rovibrational dynamics of the alkali polar dimer RbCs. ► In the model we consider the interaction of the field with the molecular polarizability. ► The potential energy surface is studied depending on the electric field strength. ► Using surfaces of section we study the phase space structure. ► We find that the molecular polarizability causes relevant effects on the system dynamics.

  13. Rovibrational dynamics of the RbCs molecule in static electric fields. Classical study

    International Nuclear Information System (INIS)

    Arnaiz, Pedro F.; Iñarrea, Manuel; Salas, J. Pablo

    2012-01-01

    We study the classical dynamics of the RbCs molecule in the presence of a static electric field. Under the Born–Oppenheimer approximation, we perform a rovibrational investigation which includes the interaction of the field with the molecular polarizability. The stability of the equilibrium points and the phase space structure of the system are explored in detail. We find that, for strong electric fields or for energies close to the dissociation threshold, the molecular polarizability causes relevant effects on the system dynamics. -- Highlights: ► We study the classical rovibrational dynamics of the alkali polar dimer RbCs. ► In the model we consider the interaction of the field with the molecular polarizability. ► The potential energy surface is studied depending on the electric field strength. ► Using surfaces of section we study the phase space structure. ► We find that the molecular polarizability causes relevant effects on the system dynamics.

  14. Current-induced domain wall motion: Separating spin torque and Oersted-field effects in Co/Pt nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Heinen, Jan; Boulle, Olivier; Rousseau, Kevin; Malinowski, Gregory; Klaeui, Mathias [Universitaet Konstanz, Fachbereich Physik, D-78457 Konstanz (Germany); Swagton, Henk J.; Koopmans, Bert [Eindhoven University of Technology, Department of Applied Physics, MB 5600 (Netherlands); Ulysse, Christian; Faini, Giancarlo [CNRS, Phynano team, Laboratoire de Photonique et de Nanostructures, 91460 Marcoussis (France)

    2010-07-01

    We report on magnetotransport studies on perpendicularly magnetized nanowires with narrow domain wall (DW) structures. Using Co/Pt multilayer nanowires, we have previously shown that Joule heating is concealing most of the current induced domain wall effects, but using a constant sample temperature a large non-adiabacity factor {beta} has been deduced. Here, we carry out experiments for both applied field directions and current polarities, starting from different DW configurations within a Hall cross. We clearly show, using the different symmetries of spin torque and Oersted-field, that the much debated Oersted-field does not contribute to the DW depinning significantly. This allows us to extract the spin torque contribution and the non-adiabacity factor {beta}, which turns out to be in line with previous measurements.

  15. Personality and Field of Study Choice in University

    Science.gov (United States)

    Humburg, Martin

    2017-01-01

    This paper demonstrates that the Big five personality traits (openness to experience, conscientiousness, extraversion, agreeableness, and emotional stability) measured at age 14 can be linked to field of study choice in university at around age 19. While personality matters less than cognitive skills, such as math ability and verbal ability, for…

  16. A study of multi-phase flow through the cathode side of an interdigitated flow field using a multi-fluid model

    DEFF Research Database (Denmark)

    Berning, Torsten; Odgaard, Madeleine; Kær, Søren Knudsen

    2010-01-01

    This work presents a study of multi-phase flow through the cathode side of a polymer electrolyte membrane fuel cell employing an interdigitated flow field plate. A previously published model has been extended in order to account for phase change kinetics, and a comparison between the interdigitated...... flow field design and a conventional straight channel design has been conducted. It is found that the parasitic pressure drop in the interdigitated design is in the range of a few thousand Pa and could be reduced to a few hundred Pa by choosing diffusion media with high in-plane permeability....... In the interdigitated design more product water is carried out of the cell in the vapor phase compared to the straight channel design which indicates that liquid water management might be less problematic. This effect also leads to the finding that in the interdigitated design more waste heat is carried out of the cell...

  17. Magnetic and velocity fields in a dynamo operating at extremely small Ekman and magnetic Prandtl numbers

    Science.gov (United States)

    Šimkanin, Ján; Kyselica, Juraj

    2017-12-01

    Numerical simulations of the geodynamo are becoming more realistic because of advances in computer technology. Here, the geodynamo model is investigated numerically at the extremely low Ekman and magnetic Prandtl numbers using the PARODY dynamo code. These parameters are more realistic than those used in previous numerical studies of the geodynamo. Our model is based on the Boussinesq approximation and the temperature gradient between upper and lower boundaries is a source of convection. This study attempts to answer the question how realistic the geodynamo models are. Numerical results show that our dynamo belongs to the strong-field dynamos. The generated magnetic field is dipolar and large-scale while convection is small-scale and sheet-like flows (plumes) are preferred to a columnar convection. Scales of magnetic and velocity fields are separated, which enables hydromagnetic dynamos to maintain the magnetic field at the low magnetic Prandtl numbers. The inner core rotation rate is lower than that in previous geodynamo models. On the other hand, dimensional magnitudes of velocity and magnetic fields and those of the magnetic and viscous dissipation are larger than those expected in the Earth's core due to our parameter range chosen.

  18. Quantifying the influence of previously burned areas on suppression effectiveness and avoided exposure: A case study of the Las Conchas Fire

    Science.gov (United States)

    Matthew P. Thompson; Patrick Freeborn; Jon D. Rieck; Dave Calkin; Julie W. Gilbertson-Day; Mark A. Cochrane; Michael S. Hand

    2016-01-01

    We present a case study of the Las Conchas Fire (2011) to explore the role of previously burned areas (wildfires and prescribed fires) on suppression effectiveness and avoided exposure. Methodological innovations include characterisation of the joint dynamics of fire growth and suppression activities, development of a fire line effectiveness framework, and...

  19. Soap-film flow induced by electric fields in asymmetric frames

    Science.gov (United States)

    Mollaei, S.; Nasiri, M.; Soltanmohammadi, N.; Shirsavar, R.; Ramos, A.; Amjadi, A.

    2018-04-01

    Net fluid flow of soap films induced by (ac or dc) electric fields in asymmetric frames is presented. Previous experiments of controllable soap film flow required the simultaneous use of an electrical current passing through the film and an external electric field or the use of nonuniform ac electric fields. Here a single voltage difference generates both the electrical current going through the film and the electric field that actuates on the charge induced on the film. The film is set into global motion due to the broken symmetry that appears by the use of asymmetric frames. If symmetric frames are used, the film flow is not steady but time dependent and irregular. Finally, we study numerically these film flows by employing the model of charge induction in ohmic liquids.

  20. Proximal sensing of within-field mycotoxin variation - a case study in Northeast Germany

    Science.gov (United States)

    Mueller, Marina; Koszinski, Sylvia; Bangs, Donovan E.; Wehrhan, Marc; Ullrich, Andreas; Verch, Gernot; Brenning, Alexander

    2017-04-01

    Fusarium head blight is a global problem in agriculture that results in yield losses and, more seriously, produces harmful toxins that enter the food chain. This study (Müller et al. 2016) builds on previous research identifying within-field humidity as an important factor in infection processes by Fusarium fungi and its mycotoxin production. Environmental variables describing topographic control of humidity (topographic wetness index TWI), soil texture and related moisture by electrical conductivity (ECa), and canopy humidity by density (normalized difference vegetation index NDVI) were explored in their relationship to the fungal infection rates and mycotoxin accumulation. Field studies at four sites in NE German Lowlands were performed in 2009 and 2011. Sites differed slightly in soil textural properties and, more pronounced, mean annual precipitation. Sampling positions were selected by usage of NDVI values range from remote sensing data base. Environmental data included elevation and its derivatives like topographic wetness index (TWI) from a DEM25, electrical conductivity distribution maps (5 x 5 m) based on EM38DD survey and, orthorectified RapidEye imagery (5 x 5 m2) with resulting NDVI distributions across the field sites. Grain yield, fungal infection rate, microbiological characteristics and mycotoxin accumulation were determined at 223 field positions. Statistical analysis incorporated Spearman rank order correlations and three regression methods (censored regression models, linear mixed-effects models and spatial linear mixed-effects models). Kriging was used to visualize the spatial patterns and trends. All analyses were performed by R software. In 2011, a more wet year than 2009, high Fusarium infection rates and a high concentration of mycotoxins were stated, the latter once exceeding EU threshold values. For both years associations between NDVI and microbiological variables were found, but being more pronounced and more often significant for 2011

  1. Wake field in matched kicker magnet

    International Nuclear Information System (INIS)

    Miyahara, Y.

    1979-01-01

    Coherent transverse instability observed in KEK booster proton synchrotron has been reported previously. This instability is induced by the interaction of the beam with kicker magnet for the fast beam extraction. To understand the mechanism completely, it is necessary to know the wake field in detail. Here, the wake field or induced current in the kicker magnet which is terminated with matched resistance is considered

  2. Correlation between two parameters of mice behaviour in the open field test

    OpenAIRE

    Stojanović, Nikola M.; Ranđelović, Pavle J.; Radulović, Niko S.

    2017-01-01

    The open field test is being used extensively for the determination of different aspects of animal behaviour for over seventy years. The correlation between different behavioural parameters obtained in this test, although previously studied, is still debatable. Thus, we aimed to analyze and correlate behaviour scores to estimate the importance of individual parameters in this type of experiment. The open field test was performed on male BALB/c mice treated with either saline (10 ml/kg) or dia...

  3. Gendered transitions to adulthood by college field of study in the United States.

    Science.gov (United States)

    Han, Siqi; Tumin, Dmitry; Qian, Zhenchao

    2016-01-01

    Field of study may influence the timing of transitions to the labor market, marriage, and parenthood among college graduates. Research to date has yet to study how field of study is associated with the interweaving of these transitions in the USA. The current study examines gendered influences of college field of study on transitions to a series of adult roles, including full-time work, marriage, and parenthood. We use Cox proportional hazards models and multinomial logistic regression to examine gendered associations between field of study and the three transitions among college graduates of the NLSY97 (National Longitudinal Survey of Youth) cohort. Men majoring in STEM achieve early transitions to full-time work, marriage, and parenthood; women majoring in STEM show no significant advantage in finding full-time work and delayed marriage and childbearing; women in business have earlier transitions to full-time work and marriage than women in other fields, demonstrating an advantage similar to that of men in STEM. The contrast between men and women in STEM shows that transition to adulthood remains gendered; the contrast between women in STEM and women in business illustrates that a prestigious career may not necessarily delay family formation.

  4. Dissociation in decision bias mechanism between probabilistic information and previous decision

    Directory of Open Access Journals (Sweden)

    Yoshiyuki eKaneko

    2015-05-01

    Full Text Available Target detection performance is known to be influenced by events in the previous trials. It has not been clear, however, whether this bias effect is due to the previous sensory stimulus, motor response, or decision. Also it remains open whether or not the previous trial effect emerges via the same mechanism as the effect of knowledge about the target probability. In the present study, we asked normal human subjects to make a decision about the presence or absence of a visual target. We presented a pre-cue indicating the target probability before the stimulus, and also a decision-response mapping cue after the stimulus so as to tease apart the effect of decision from that of motor response. We found that the target detection performance was significantly affected by the probability cue in the current trial and also by the decision in the previous trial. While the information about the target probability modulated the decision criteria, the previous decision modulated the sensitivity to target-relevant sensory signals (d-prime. Using functional magnetic resonance imaging, we also found that activation in the left intraparietal sulcus was decreased when the probability cue indicated a high probability of the target. By contrast, activation in the right inferior frontal gyrus was increased when the subjects made a target-present decision in the previous trial, but this change was observed specifically when the target was present in the current trial. Activation in these regions was associated with individual-difference in the decision computation parameters. We argue that the previous decision biases the target detection performance by modulating the processing of target-selective information, and this mechanism is distinct from modulation of decision criteria due to expectation of a target.

  5. Dissociation in decision bias mechanism between probabilistic information and previous decision

    Science.gov (United States)

    Kaneko, Yoshiyuki; Sakai, Katsuyuki

    2015-01-01

    Target detection performance is known to be influenced by events in the previous trials. It has not been clear, however, whether this bias effect is due to the previous sensory stimulus, motor response, or decision. Also it remains open whether or not the previous trial effect emerges via the same mechanism as the effect of knowledge about the target probability. In the present study, we asked normal human subjects to make a decision about the presence or absence of a visual target. We presented a pre-cue indicating the target probability before the stimulus, and also a decision-response mapping cue after the stimulus so as to tease apart the effect of decision from that of motor response. We found that the target detection performance was significantly affected by the probability cue in the current trial and also by the decision in the previous trial. While the information about the target probability modulated the decision criteria, the previous decision modulated the sensitivity to target-relevant sensory signals (d-prime). Using functional magnetic resonance imaging (fMRI), we also found that activation in the left intraparietal sulcus (IPS) was decreased when the probability cue indicated a high probability of the target. By contrast, activation in the right inferior frontal gyrus (IFG) was increased when the subjects made a target-present decision in the previous trial, but this change was observed specifically when the target was present in the current trial. Activation in these regions was associated with individual-difference in the decision computation parameters. We argue that the previous decision biases the target detection performance by modulating the processing of target-selective information, and this mechanism is distinct from modulation of decision criteria due to expectation of a target. PMID:25999844

  6. Gendered transitions to adulthood by college field of study in the United States

    Directory of Open Access Journals (Sweden)

    Siqi Han

    2016-09-01

    Full Text Available Background: Field of study may influence the timing of transitions to the labor market, marriage, and parenthood among college graduates. Research to date has yet to study how field of study is associated with the interweaving of these transitions in the USA. Objective: The current study examines gendered influences of college field of study on transitions to a series of adult roles, including full-time work, marriage, and parenthood. Methods: We use Cox proportional hazards models and multinomial logistic regression to examine gendered associations between field of study and the three transitions among college graduates of the NLSY97 (National Longitudinal Survey of Youth cohort. Results: Men majoring in STEM achieve early transitions to full-time work, marriage, and parenthood; women majoring in STEM show no significant advantage in finding full-time work and delayed marriage and childbearing; women in business have earlier transitions to full-time work and marriage than women in other fields, demonstrating an advantage similar to that of men in STEM. Conclusions: The contrast between men and women in STEM shows that transition to adulthood remains gendered; the contrast between women in STEM and women in business illustrates that a prestigious career may not necessarily delay family formation. Contribution: The paper shows how stratification by field of study creates gendered demographic outcomes for college graduates. It also demonstrates that women's decisions regarding marriage and parenthood do not uniformly respond to the economic prospect of their work.

  7. Electric field and electron density thresholds for coherent auroral echo onset

    International Nuclear Information System (INIS)

    Kustov, A.V.; Uspensky, M.V.; Sofko, G.J.; Koehler, J.A.; Jones, G.O.L.; Williams, P.J.S.

    1993-01-01

    The authors study the threshold dependence of electron density and electric field for the observation of coherent auroral echo onset. They make use of Polar Geophysical Institute 83 MHz auroral radar and the EISCAT facility in Scandanavia, to simultaneously get plasma parameter information and coherent scatter observations. They observe an electron density threshold of roughly 2.5x10 11 m -3 for electric fields of 15 - 20 mV/m (near the Farley-Buneman instability threshold). For electric fields of 5 - 10 mV/m echos are not observed for even twice the previous electron density. Echo strength is observed to have other parametric dependences

  8. Supporting Medical Students to Do International Field Research: A Case Study

    Science.gov (United States)

    Pearson, Stephen; Parr, Jennifer; Ullah, Zafar; Omar, Maye

    2014-01-01

    Field research can benefit medical students' learning through experiential engagement with research and personal exposure to foreign health systems. However, the off-campus nature of the activity raises challenges for teachers. This article presents a case study that illustrates the benefits and challenges of organising a field research project…

  9. Modeling study of the Pauzhetsky geothermal field, Kamchatka, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Kiryukhin, A.V. [Institute of Volcanology, Kamchatsky (Russian Federation); Yampolsky, V.A. [Kamchatskburgeotermia State Enterprise, Elizovo (Russian Federation)

    2004-08-01

    Exploitation of the Pauzhetsky geothermal field started in 1966 with a 5 MW{sub e} power plant. A hydrogeological model of the Pauzhetsky field has been developed based on an integrated analysis of data on lithological units, temperature, pressure, production zones and natural discharge distributions. A one-layer 'well by well' model with specified vertical heat and mass exchange conditions has been used to represent the main features of the production reservoir. Numerical model development was based on the TOUGH2 code [Pruess, 1991. TOUGH2 - A General Purpose Numerical Simulator for Multiphase Fluid and Heat Flow, Lawrence Berkeley National Laboratory Report, Berkeley, CA; Pruess et al., 1999. TOUGH2 User's Guide, Version 2.0, Report LBNL-43134, Lawrence Berkeley National Laboratory, Berkeley, CA] coupled with tables generated by the HOLA wellbore simulator [Aunzo et al., 1991. Wellbore Models GWELL, GWNACL, and HOLA, Users Guide, Draft, 81 pp.]. Lahey Fortran-90 compiler and computer graphical packages (Didger-3, Surfer-8, Grapher-3) were also used to model the development process. The modeling study of the natural-state conditions was targeted on a temperature distribution match to estimate the natural high-temperature upflow parameters: the mass flow-rate was estimated at 220 kg/s with enthalpy of 830-920 kJ/kg. The modeling study for the 1964-2000 exploitation period of the Pauzhetsky geothermal field was targeted at matching the transient reservoir pressure and flowing enthalpies of the production wells. The modeling study of exploitation confirmed that 'double porosity' in the reservoir, with a 10-20% active volume of 'fractures', and a thermo-mechanical response to reinjection (including changes in porosity due to compressibility and expansivity), were the key parameters of the model. The calibrated model of the Pauzhetsky geothermal field was used to forecast reservoir behavior under different exploitation scenarios for

  10. On the Seismic Response of Protected and Unprotected Middle-Rise Steel Frames in Far-Field and Near-Field Areas

    Directory of Open Access Journals (Sweden)

    Dora Foti

    2014-01-01

    Full Text Available Several steel moment-resisting framed buildings were seriously damaged during Northridge (1994; Kobe (1995; Kocaeli, Turkey (1999, earthquakes. Indeed, for all these cases, the earthquake source was located under the urban area and most victims were in near-field areas. In fact near-field ground motions show velocity and displacement peaks higher than far-field ones. Therefore, the importance of considering near-field ground motion effects in the seismic design of structures is clear. This study analyzes the seismic response of five-story steel moment-resisting frames subjected to Loma Prieta (1989 earthquake—Gilroy (far-field register and Santa Cruz (near-field register. The design of the frames verifies all the resistance and stability Eurocodes’ requirements and the first mode has been determined from previous shaking-table tests. In the frames two diagonal braces are installed in different positions. Therefore, ten cases with different periods are considered. Also, friction dampers are installed in substitution of the braces. The behaviour of the braced models under the far-field and the near-field records is analysed. The responses of the aforementioned frames equipped with friction dampers and subjected to the same ground motions are discussed. The maximum response of the examined model structures with and without passive dampers is analysed in terms of damage indices, acceleration amplification, base shear, and interstory drifts.

  11. Earthworm activities in cassava and egusi melon fields in the transitional zone of Benin: linking farmers' perceptions with field studies

    NARCIS (Netherlands)

    Saïdou, A.; Kossou, D.; Brussaard, L.; Richards, P.; Kuyper, T.W.

    2008-01-01

    Farmers' perceptions of earthworm activities were studied in the transitional zone of Benin and linked to scientific explanations of earthworm casting activities. Earthworm activity was assessed in farmers' fields with three different cassava cultivars and in a field experiment with three different

  12. Predictive effects of previous episodes on the risk of recurrence in depressive and bipolar disorders

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Andersen, Per Kragh

    2005-01-01

    Findings from several studies have suggested that the risk of recurrence increases with the number of previous episodes in depressive and bipolar disorders. However, a comprehensive and critical review of the literature published during the past century shows that in several previous studies...

  13. Field measurements of radium in the human body

    International Nuclear Information System (INIS)

    Toohey, R.E.; May, H.A.

    1978-01-01

    Two whole body counting systems have been developed and employed for field measurements. The radium contents of nine previously unmeasured cases have been determined during three field trips. Future trips are being scheduled to make body radioactivity measurements on a specific subpopulation of CHR radium cases

  14. International Geomagnetic Reference Field: the 12th generation

    DEFF Research Database (Denmark)

    Thébault, Erwan; Finlay, Chris; Beggan, Ciarán D.

    2015-01-01

    The 12th generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2014 by the Working Group V-MOD appointed by the International Association of Geomagnetism and Aeronomy (IAGA). It updates the previous IGRF generation with a definitive main field model for epoch ...

  15. Quasi-experimental Studies in the Fields of Infection Control and Antibiotic Resistance, Ten Years Later: A Systematic Review.

    Science.gov (United States)

    Alsaggaf, Rotana; O'Hara, Lyndsay M; Stafford, Kristen A; Leekha, Surbhi; Harris, Anthony D

    2018-02-01

    OBJECTIVE A systematic review of quasi-experimental studies in the field of infectious diseases was published in 2005. The aim of this study was to assess improvements in the design and reporting of quasi-experiments 10 years after the initial review. We also aimed to report the statistical methods used to analyze quasi-experimental data. DESIGN Systematic review of articles published from January 1, 2013, to December 31, 2014, in 4 major infectious disease journals. METHODS Quasi-experimental studies focused on infection control and antibiotic resistance were identified and classified based on 4 criteria: (1) type of quasi-experimental design used, (2) justification of the use of the design, (3) use of correct nomenclature to describe the design, and (4) statistical methods used. RESULTS Of 2,600 articles, 173 (7%) featured a quasi-experimental design, compared to 73 of 2,320 articles (3%) in the previous review (Pquasi-experimental design; and 68 (39%) identified their design using the correct nomenclature. In addition, 2-group statistical tests were used in 75 studies (43%); 58 studies (34%) used standard regression analysis; 18 (10%) used segmented regression analysis; 7 (4%) used standard time-series analysis; 5 (3%) used segmented time-series analysis; and 10 (6%) did not utilize statistical methods for comparisons. CONCLUSIONS While some progress occurred over the decade, it is crucial to continue improving the design and reporting of quasi-experimental studies in the fields of infection control and antibiotic resistance to better evaluate the effectiveness of important interventions. Infect Control Hosp Epidemiol 2018;39:170-176.

  16. Molecular modeling studies of structural properties of polyvinyl alcohol: a comparative study using INTERFACE force field.

    Science.gov (United States)

    Radosinski, Lukasz; Labus, Karolina

    2017-10-05

    Polyvinyl alcohol (PVA) is a material with a variety of applications in separation, biotechnology, and biomedicine. Using combined Monte Carlo and molecular dynamics techniques, we present an extensive comparative study of second- and third-generation force fields Universal, COMPASS, COMPASS II, PCFF, and the newly developed INTERFACE, as applied to this system. In particular, we show that an INTERFACE force field provides a possibility of composing a reliable atomistic model to reproduce density change of PVA matrix in a narrow temperature range (298-348 K) and calculate a thermal expansion coefficient with reasonable accuracy. Thus, the INTERFACE force field may be used to predict mechanical properties of the PVA system, being a scaffold for hydrogels, with much greater accuracy than latter approaches. Graphical abstract Molecular Dynamics and Monte Carlo studies indicate that it is possible to predict properties of the PVA in narrow temperature range by using the INTERFACE force field.

  17. A novel background field removal method for MRI using projection onto dipole fields (PDF).

    Science.gov (United States)

    Liu, Tian; Khalidov, Ildar; de Rochefort, Ludovic; Spincemaille, Pascal; Liu, Jing; Tsiouris, A John; Wang, Yi

    2011-11-01

    For optimal image quality in susceptibility-weighted imaging and accurate quantification of susceptibility, it is necessary to isolate the local field generated by local magnetic sources (such as iron) from the background field that arises from imperfect shimming and variations in magnetic susceptibility of surrounding tissues (including air). Previous background removal techniques have limited effectiveness depending on the accuracy of model assumptions or information input. In this article, we report an observation that the magnetic field for a dipole outside a given region of interest (ROI) is approximately orthogonal to the magnetic field of a dipole inside the ROI. Accordingly, we propose a nonparametric background field removal technique based on projection onto dipole fields (PDF). In this PDF technique, the background field inside an ROI is decomposed into a field originating from dipoles outside the ROI using the projection theorem in Hilbert space. This novel PDF background removal technique was validated on a numerical simulation and a phantom experiment and was applied in human brain imaging, demonstrating substantial improvement in background field removal compared with the commonly used high-pass filtering method. Copyright © 2011 John Wiley & Sons, Ltd.

  18. Geomagnetic Observations for Main Field Studies

    DEFF Research Database (Denmark)

    Matzka, Jürgen; Chulliat, A.; Mandea, M.

    2010-01-01

    Direct measurements of the geomagnetic field have been made for more than 400 years, beginning with individual determinations of the angle between geographic and magnetic North. This was followed by the start of continuous time series of full vector measurements at geomagnetic observatories...... and the beginning of geomagnetic repeat stations surveys in the 19th century. In the second half of the 20th century, true global coverage with geomagnetic field measurements was accomplished by magnetometer payloads on low-Earth-orbiting satellites. This article describes the procedures and instruments...... for magnetic field measurements on ground and in space and covers geomagnetic observatories, repeat stations, automatic observatories, satellites and historic observations. Special emphasis is laid on the global network of geomagnetic observatories....

  19. Field studies of HT oxidation and dispersion in the environment

    International Nuclear Information System (INIS)

    Brown, R.M.; Ogram, G.L.; Spencer, F.S.; Ontario Hydro, Toronto, ON

    1988-10-01

    A tracer quantity of 3.54 TBq tritiated hydrogen (HT) was released into the atmosphere at a Chalk River, Ontario field site to determine the behaviour of HT in the environment. The primary objective was to establish the oxidation rate of HT to tritiated water (HTO) in air, soil and vegetation compartments. HTO/HT atmospheric concentration ratios observed during the release ranged from 0.14 x 10 -4 at 5 m to 7.0 x 10 -4 at 400 m distance from the release point indicating an effective oxidation rate of about 1.5% h -1 . Gas phase oxidation in the atmosphere would be less than this effective rate. Results confirm that surface soils play the dominant role in converting HT to HTO. Soil HT deposition velocities were between 2.7 x 10 -4 and 11 x 10 -4 m s -1 for an open field of varied composition, and between 3.3 x 10 -4 and 12 x 10 -4 m s -1 for a conifer forest. Soil HTO loss rates were initially 1 to 3 % h -1 averaged over the first 24 h after release. Vegetation tissue-free water tritium (TFWT) resulted from uptake of soil HTO and exchange with atmospheric HTO vapour. Upper limit HT deposition velocities to vegetation measured as TFWT in 5 species were 0.23 x 10 -7 to 6 x 10 -7 m s -1 expressed on a leaf area basis. TFWT loss rates were 5.2 to 8.1 % h -1 from about 12 to 48 h after release with low activity rain and 0.42 to 0.56 % h -1 from about 48 to 335 h. Vegetation organically-bound tritium/TFWT specific activity ratios (Bq g -1 H) were about 0.1 initially, increasing to 16 after 113 days as TFWT specific activity declined more rapidly than that of OBT. The effective HT oxidation rate, deposition velocities and HTO loss rates were in good agreement with a 1986 HT field release and previous laboratory experiments

  20. High breakdown electric field in β-Ga2O3/graphene vertical barristor heterostructure

    Science.gov (United States)

    Yan, Xiaodong; Esqueda, Ivan S.; Ma, Jiahui; Tice, Jesse; Wang, Han

    2018-01-01

    In this work, we study the high critical breakdown field in β-Ga2O3 perpendicular to its (100) crystal plane using a β-Ga2O3/graphene vertical heterostructure. Measurements indicate a record breakdown field of 5.2 MV/cm perpendicular to the (100) plane that is significantly larger than the previously reported values on lateral β-Ga2O3 field-effect-transistors (FETs). This result is compared with the critical field typically measured within the (100) crystal plane, and the observed anisotropy is explained through a combined theoretical and experimental analysis.

  1. THE FUTURE OF INTERNATIONAL BUSINESS AS A STUDY FIELD

    Directory of Open Access Journals (Sweden)

    Marcos Amatucci

    2010-12-01

    Full Text Available The field of International Business lies at a crossroads of analytical levels, themes and theoretical traditions, and it will probably remain at this point in the near future. This work follows five years (2001-2006 of the Journal of International Business Studies (JIBS to analyse the scope and evolution of themes, methodologies and theoretical traditions in 199 articles. After this phase, it discusses, with the help of colleagues gathered in two workshops, the future of the area in terms of two hypotheses: the convergence hypothesis of the dominance of a theoretical and thematic mainstream, and the divergence hypothesis of a “theoretical quilt” configuration of the field. It concludes that the editorial preferences of JIBS favour traditional approaches to the field and that the second “future” is the most likely to occur, leading International Business to evolve as a social reference more than an epistemological entity.

  2. Theoretical study of in-plane response of magnetic field sensor to magnetic beads magnetized by the sensor self-field

    DEFF Research Database (Denmark)

    Hansen, Troels Borum Grave; Damsgaard, Christian Danvad; Dalslet, Bjarke Thomas

    2010-01-01

    We present a theoretical study of the spatially averaged in-plane magnetic field on square and rectangular magnetic field sensors from a single magnetic bead, a monolayer of magnetic beads, and a half-space filled with magnetic beads being magnetized by the magnetic self-field due to the applied...... bias current through the sensor. The analysis of the single bead response shows that beads always contribute positively to the average magnetic field as opposed to the case for an applied homogeneous magnetic field where the sign of the signal depends on the bead position. General expressions...... and analytical approximations are derived for the sensor response to beads as function of the bead distribution, the bias current, the geometry and size of the sensor, and the bead characteristics. Consequences for the sensor design are exemplified and it is described how the contribution from the self...

  3. Zero-point field in curved spaces

    International Nuclear Information System (INIS)

    Hacyan, S.; Sarmiento, A.; Cocho, G.; Soto, F.

    1985-01-01

    Boyer's conjecture that the thermal effects of acceleration are manifestations of the zero-point field is further investigated within the context of quantum field theory in curved spaces. The energy-momentum current for a spinless field is defined rigorously and used as the basis for investigating the energy density observed in a noninertial frame. The following examples are considered: (i) uniformly accelerated observers, (ii) two-dimensional Schwarzschild black holes, (iii) the Einstein universe. The energy spectra which have been previously calculated appear in the present formalism as an additional contribution to the energy of the zero-point field, but particle creation does not occur. It is suggested that the radiation produced by gravitational fields or by acceleration is a manifestation of the zero-point field and of the same nature (whether real or virtual)

  4. Evaluation of Theses in the Field of Social Studies Education in Turkey

    Directory of Open Access Journals (Sweden)

    Bülent Tarman

    2010-12-01

    Full Text Available The purpose of this study is to analyze theses in the field of social studies education, and understand certain issues rose through these studies, and determine the awareness level of researchers in Turkey. The theses are examined through computer-based screening system to collect the data. "National Thesis Center" website of Council of Higher Education (CHE is used for this purpose. Besides, the data is collected through the online database system of several university libraries. This is a mixed qualitative and quantitative research study. This study is conducted by scanning and doing content analysis of 294 masters‟ and 41 doctoral theses. These theses were grouped in terms of what research methods used in these studies; which year the studies are completed, and what universities the studies are carried out. Among the total number of 294 Social Studies master‟s theses, 33 of them are about the curriculum while 27 of them are on the student achievement in Social Studies. Examination of these theses shows that the topics of the theses fall within a certain framework of Social Studies. There have rarely seen topics selected to study out of this framework. The results stemming from this research also reveal that different ways of thinking in the field of Social Studies is necessary for development of the field. Therefore, this study has an important role to prevent the accumulation of similar studies in the field by providing guidance to researchers and their academic advisors so that they can generate more effective and efficient human resources in Social Studies

  5. Automatic electromagnetic valve for previous vacuum

    International Nuclear Information System (INIS)

    Granados, C. E.; Martin, F.

    1959-01-01

    A valve which permits the maintenance of an installation vacuum when electric current fails is described. It also lets the air in the previous vacuum bomb to prevent the oil ascending in the vacuum tubes. (Author)

  6. MUSE integral-field spectroscopy towards the Frontier Fields Cluster Abell S1063

    DEFF Research Database (Denmark)

    Karman, W.; Caputi, K. I.; Grillo, C.

    2015-01-01

    We present the first observations of the Frontier Fields Cluster Abell S1063 taken with the newly commissioned Multi Unit Spectroscopic Explorer (MUSE) integral field spectrograph. Because of the relatively large field of view (1 arcmin^2), MUSE is ideal to simultaneously target multiple galaxies...... the cluster, we find 17 galaxies at higher redshift, including three previously unknown Lyman-alpha emitters at z>3, and five multiply-lensed galaxies. We report the detection of a new z=4.113 multiply lensed galaxy, with images that are consistent with lensing model predictions derived for the Frontier...... of scientific topics that can be addressed with a single MUSE pointing. We conclude that MUSE is a very efficient instrument to observe galaxy clusters, enabling their mass modelling, and to perform a blind search for high-redshift galaxies....

  7. Planetary geomorphology field studies: Washington and Alaska

    Science.gov (United States)

    Malin, M. C.

    1984-01-01

    Field studies of terrestrial landforms and the processes that shape them provide new directions to the study of planetary features. Investigations discussed address principally mudflow phenomena and drainage development. At the Valley of 10,000 Smokes (Katmai, AK) and Mount St. Helens, WA, studies of the development of erosional landforms (in particular, drainage) on fresh, new surfaces permitted analysis of the result of competition between geomorphic processes. Of specific interest is the development of stream pattern as a function of the competition between perennial seepage overland flow (from glacial or groundwater sources), ephemeral overland flow (from pluvial or seasonal melt sources), and ephemeral/perennial groundwater sapping, as a function of time since initial resurfacing, material properties, and seasonal/annual environmental conditions.

  8. Mobility of solid vortex matter in 'shaking' ac magnetic fields of variable amplitude

    International Nuclear Information System (INIS)

    Moreno, A.J.; Valenzuela, S.O.; Pasquini, G.; Bekeris, V.

    2004-01-01

    The vortex solid in high temperature superconductors exhibits several regimes and dynamical behaviors. A temporarily symmetric magnetic ac field (e.g. sinusoidal, square, triangular) can increase the vortex lattice mobility and a temporarily asymmetric one (e.g. sawtooth) can decrease it. In this work, we study the effect on the mobility of the vortex solid as a function of the amplitude of an ac symmetric 'shaking' field when it is applied to previously prepared high and low mobility configurations. This study was carried out in high quality twinned YBCO single crystals and vortex mobility was studied through ac susceptibility measurements

  9. Does previous use affect litter box appeal in multi-cat households?

    Science.gov (United States)

    Ellis, J J; McGowan, R T S; Martin, F

    2017-08-01

    It is commonly assumed that cats actively avoid eliminated materials (especially in multi-cat homes), suggesting regular litter box cleaning as the best defense against out-of-box elimination. The relationship between previous use and litter box appeal to familiar subsequent users is currently unknown. The purpose of this study was to investigate the relationship between previous litter box use and the identity of the previous user, type of elimination, odor, and presence of physical/visual obstructions in a multi-cat household scenario. Cats preferred a clean litter box to a dirty one, but the identity of the previous user had no impact on preferences. While the presence of odor from urine and/or feces did not impact litter box preferences, the presence of odorless faux-urine and/or feces did - with the presence of faux-feces being preferred over faux-urine. Results suggest neither malodor nor chemical communication play a role in litter box preferences, and instead emphasize the importance of regular removal of physical/visual obstructions as the key factor in promoting proper litter box use. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Binge drinking and alcohol prices: a systematic review of age-related results from econometric studies, natural experiments and field studies.

    Science.gov (United States)

    Nelson, Jon P

    2015-01-01

    Heavy episodic ("binge") drinking of alcohol has serious public health implications, especially for youth and young adults. Previous summaries and surveys have failed to address in a comprehensive manner the effects of alcohol prices on binge drinking by gender or age group. A qualitative systematic review is performed for effects of alcohol prices (or tax surrogates) on binge drinking for three age groups: youth, young adults, and adults. Outcomes examined include binge participation, intensity and frequency. Criteria for data collection and potential sources of bias are discussed, including adequacy of price data. Price-binge relationships are judged using a 95% confidence interval (p ≤ 0.05) for statistical significance. Fifty-six relevant econometric studies were found, with studies and results distributed equally among three age groups. Also found were five natural experiments for tax reductions and six field studies. Null results or mixed results are found in more than half of the studies. The body of evidence indicates that binge drinkers are not highly-responsive to increased prices. Non-responsiveness holds generally for younger and older drinkers and for male and female binge drinkers alike. A limitation of the current literature is that results are only available for higher-income countries. Increased alcohol taxes or prices are unlikely to be effective as a means to reduce binge drinking, regardless of gender or age group.

  11. Unified field theory with Einsteinian photons and heavy bosons as field quants

    Energy Technology Data Exchange (ETDEWEB)

    Treder, H J

    1975-08-01

    After discussing previously the classical electrodynamics which corresponds to the quantum electrodynamics with two sorts of photons (photons with zero rest mass and nonvanishing rest mass), the general field theory of a vector field A/sup v/ with two sorts if field quanta is given. It is shown that the postulate for the ''unity of the four-current'' determining the physical contents of this theory makes it possible to regard it as a classical ansatz of a unified theory of the electromagnetic and the weak interactions. From the ''unity of the currents'' results that the electrons are delta-like point-particles with a finite self-potential and finite field masses M = epsilon/sup 2//2 kc/sup -2/. The Compton wave-length of the heavy photons k/sup -1/ = h/mc has the meaning of an ''elementary length'' of the electromagnetic interactions and the rest mass m = khc/sup -1/ of these bosons is of the order of a baryon mass. (auth)

  12. Tellurium adsorption on tungsten and molybdenum field emitters

    International Nuclear Information System (INIS)

    Collins, R.A.; Kiwanga, C.A.

    1977-01-01

    Studies of the adsorption of tellurium onto tungsten and molybdenum field emitters are described and the results obtained are compared with those obtained in previous work on the adsorption of silicon and selenium. The adsorption of Te onto W was found to be much more uniform than in the case of Se. Although Te is metallic in many of its properties its adsorptive behavior on field emitters is found to be similar to that of selenium and these adsorptive properties are basically common to all semiconductors. The most evident property of these adsorbates is that the work function and emission current decrease simultaneously at coverages of less than half a monolayer and the work function subsequently increases. (B.D.)

  13. Halo nuclei studied by relativistic mean-field approach

    International Nuclear Information System (INIS)

    Gmuca, S.

    1997-01-01

    Density distributions of light neutron-rich nuclei are studied by using the relativistic mean-field approach. The effective interaction which parameterizes the recent Dirac-Brueckner-Hartree-Fock calculations of nuclear matter is used. The results are discussed and compared with the experimental observations with special reference to the neutron halo in the drip-line nuclei. (author)

  14. Gendered transitions to adulthood by college field of study in the United States

    Science.gov (United States)

    Han, Siqi; Tumin, Dmitry; Qian, Zhenchao

    2017-01-01

    BACKGROUND Field of study may influence the timing of transitions to the labor market, marriage, and parenthood among college graduates. Research to date has yet to study how field of study is associated with the interweaving of these transitions in the USA. OBJECTIVE The current study examines gendered influences of college field of study on transitions to a series of adult roles, including full-time work, marriage, and parenthood. METHODS We use Cox proportional hazards models and multinomial logistic regression to examine gendered associations between field of study and the three transitions among college graduates of the NLSY97 (National Longitudinal Survey of Youth) cohort. RESULTS Men majoring in STEM achieve early transitions to full-time work, marriage, and parenthood; women majoring in STEM show no significant advantage in finding full-time work and delayed marriage and childbearing; women in business have earlier transitions to full-time work and marriage than women in other fields, demonstrating an advantage similar to that of men in STEM. CONCLUSIONS The contrast between men and women in STEM shows that transition to adulthood remains gendered; the contrast between women in STEM and women in business illustrates that a prestigious career may not necessarily delay family formation. PMID:29075146

  15. Electric fields in plasmas under pulsed currents

    International Nuclear Information System (INIS)

    Tsigutkin, K.; Doron, R.; Stambulchik, E.; Bernshtam, V.; Maron, Y.; Fruchtman, A.; Commisso, R. J.

    2007-01-01

    Electric fields in a plasma that conducts a high-current pulse are measured as a function of time and space. The experiment is performed using a coaxial configuration, in which a current rising to 160 kA in 100 ns is conducted through a plasma that prefills the region between two coaxial electrodes. The electric field is determined using laser spectroscopy and line-shape analysis. Plasma doping allows for three-dimensional spatially resolved measurements. The measured peak magnitude and propagation velocity of the electric field is found to match those of the Hall electric field, inferred from the magnetic-field front propagation measured previously

  16. Study of the cosmological evolution of the magnetic field

    International Nuclear Information System (INIS)

    Dubois, Yohan

    2008-01-01

    In numerical models within the standard hierarchical structure formation, galaxies contain too much stars in comparison with observations. That is called the over-cooling dilemma. I have studied the galactic wind formation produced by the supernovae explosions using the numerical code RAMSES and a bunch of analytical tools. I have underlined the central role of the infalling gas accreting on galactic disks, and I have determined the conditions under which this accretion can prevent any gas ejection on large scales. It appears that winds are unable to elucidate the over-cooling problem in quiescent star forming galaxies. On the other hand, dwarf galaxies, capable to form such super-winds, are responsible for the metallic and magnetic enrichment of the extra-galactic medium. Using the same numerical tool, I performed the first simulation of the formation of a galactic win with magnetic fields. Numerical simulations of galactic wind formation with magnetic fields show the necessity of some amplification process occurring in galaxies: associated to a strong stellar dynamo, supernovae explosions can originate the residual magnetic field of the Universe. The magnetic field present on large scales is therefore amplified when the hot gas of the galaxy cluster collapses. By achieving the first magnetic cosmological simulation of the formation of a cluster and its galaxies, I was able to point out the necessity of accounting for the cooling processes to properly describe the magnetic field evolution inside the cluster core and to reconcile simulations with observational values. (author) [fr

  17. Environmental survey of the Heidrun Field 1993

    Energy Technology Data Exchange (ETDEWEB)

    Oug, E.; Lind, K.; Konieczny, R.M.

    1994-12-31

    This report presents the first regular bottom condition monitoring of the Heidrun field since the drilling programme began in 1992. This is an oil and gas field at Haltenbanken on the coastal shelf NW of Troendelag about 175 km from the Norwegian coast. Physical, chemical and biological aspects were characterized at 18 sites along four transect axes from the platform position. THC and metals were at background levels at most sites. Concentrations of ethers from a new drilling mud - Aquamud II - were generally low. Increased levels of barium and ethers were observed at the position of the discharges of drill cuttings. The seabed fauna was sparse with few species and individuals. The conditions were generally similar to the conditions described in previous baseline studies, except that the fauna was strongly reduced since 1988, which presumably reflects a large natural variation. It is concluded that the operations and drilling activities in the field had not affected the bottom environment in significant ways. 19 refs., 50 figs., 25 tabs.

  18. Learning to Recognize Patterns: Changes in the Visual Field with Familiarity

    Science.gov (United States)

    Bebko, James M.; Uchikawa, Keiji; Saida, Shinya; Ikeda, Mitsuo

    1995-01-01

    Two studies were conducted to investigate changes which take place in the visual information processing of novel stimuli as they become familiar. Japanese writing characters (Hiragana and Kanji) which were unfamiliar to two native English speaking subjects were presented using a moving window technique to restrict their visual fields. Study time for visual recognition was recorded across repeated sessions, and with varying visual field restrictions. The critical visual field was defined as the size of the visual field beyond which further increases did not improve the speed of recognition performance. In the first study, when the Hiragana patterns were novel, subjects needed to see about half of the entire pattern simultaneously to maintain optimal performance. However, the critical visual field size decreased as familiarity with the patterns increased. These results were replicated in the second study with more complex Kanji characters. In addition, the critical field size decreased as pattern complexity decreased. We propose a three component model of pattern perception. In the first stage a representation of the stimulus must be constructed by the subject, and restricting of the visual field interferes dramatically with this component when stimuli are unfamiliar. With increased familiarity, subjects become able to reconstruct a previous representation from very small, unique segments of the pattern, analogous to the informativeness areas hypothesized by Loftus and Mackworth [J. Exp. Psychol., 4 (1978) 565].

  19. HEART TRANSPLANTATION IN PATIENTS WITH PREVIOUS OPEN HEART SURGERY

    Directory of Open Access Journals (Sweden)

    R. Sh. Saitgareev

    2016-01-01

    Full Text Available Heart Transplantation (HTx to date remains the most effective and radical method of treatment of patients with end-stage heart failure. The defi cit of donor hearts is forcing to resort increasingly to the use of different longterm mechanical circulatory support systems, including as a «bridge» to the follow-up HTx. According to the ISHLT Registry the number of recipients underwent cardiopulmonary bypass surgery increased from 40% in the period from 2004 to 2008 to 49.6% for the period from 2009 to 2015. HTx performed in repeated patients, on the one hand, involves considerable technical diffi culties and high risks; on the other hand, there is often no alternative medical intervention to HTx, and if not dictated by absolute contradictions the denial of the surgery is equivalent to 100% mortality. This review summarizes the results of a number of published studies aimed at understanding the immediate and late results of HTx in patients, previously underwent open heart surgery. The effect of resternotomy during HTx and that of the specifi c features associated with its implementation in recipients previously operated on open heart, and its effects on the immediate and long-term survival were considered in this review. Results of studies analyzing the risk factors for perioperative complications in repeated recipients were also demonstrated. Separately, HTx risks after implantation of prolonged mechanical circulatory support systems were examined. The literature does not allow to clearly defi ning the impact factor of earlier performed open heart surgery on the course of perioperative period and on the prognosis of survival in recipients who underwent HTx. On the other hand, subject to the regular fl ow of HTx and the perioperative period the risks in this clinical situation are justifi ed as a long-term prognosis of recipients previously conducted open heart surgery and are comparable to those of patients who underwent primary HTx. Studies

  20. Geomagnetic field models for satellite angular motion studies

    Science.gov (United States)

    Ovchinnikov, M. Yu.; Penkov, V. I.; Roldugin, D. S.; Pichuzhkina, A. V.

    2018-03-01

    Four geomagnetic field models are discussed: IGRF, inclined, direct and simplified dipoles. Geomagnetic induction vector expressions are provided in different reference frames. Induction vector behavior is compared for different models. Models applicability for the analysis of satellite motion is studied from theoretical and engineering perspectives. Relevant satellite dynamics analysis cases using analytical and numerical techniques are provided. These cases demonstrate the benefit of a certain model for a specific dynamics study. Recommendations for models usage are summarized in the end.

  1. Maize production and land degradation: a Portuguese agriculture field case study

    Science.gov (United States)

    Ferreira, Carla S. S.; Pato, João V.; Moreira, Pedro M.; Valério, Luís M.; Guilherme, Rosa; Casau, Fernando J.; Santos, Daniela; Keizer, Jacob J.; Ferreira, António J. D.

    2016-04-01

    While food security is a main challenge faced by human kind, intensive agriculture often leads to soil degradation which then can threaten productivity. Maize is one of the most important crops across the world, with 869 million tons produced worldwide in 2012/2013 (IGC 2015), of which 929.5 thousand tons in Portugal (INE 2014). In Portugal, maize is sown in April/May and harvest occurs generally in October. Conventional maize production requires high inputs of water and fertilizers to achieve higher yields. As Portuguese farmers are typically rather old (on average, 63 years) and typically have a low education level (INE 2014), sustainability of their land management practises is often not a principal concern. This could explain why, in 2009, only 4% of the Portuguese temporary crops were under no-tillage, why only 8% of the farmers performed soil analyses in the previous three years, and why many soils have a low organic matter content (INE 2014). Nonetheless, sustainable land management practices are generally accepted to be the key to reducing agricultural soil degradation, preventing water pollution, and assuring long-term crop production objectives and food security. Sustainable land management should therefore not only be a concern for policy makers but also for farmers, since land degradation will have negative repercussions on the productivity, thus, on their economical income. This paper aims to assess the impact of maize production on soil properties. The study focusses on an 8 ha maize field located in central Portugal, with a Mediterranean climate on a gently sloping terrain (<3%) and with a soil classified as Eutric Fluvisol. On the field, several experiments were carried out with different maize varieties as well as with different fertilizers (solid, liquid and both). Centre pivot irrigation was largely used. Data is available from 2003, and concerns crop yield, fertilization and irrigation practices, as well as soil properties assessed through

  2. Higher Education as a Field of Study and Research in Europe

    Science.gov (United States)

    Kehm, Barbara M.

    2015-01-01

    This article describes the emergence of higher education as a field of research, scholarship and study. In the first part, the meaning of higher education as a field of research is defined contrasting Europe and the US. Then, the institutional basis of higher education research in Europe is analysed (learned societies, institutes and centres,…

  3. Magnetohydrodynamic implosion symmetry and suppression of Richtmyer-Meshkov instability in an octahedrally symmetric field

    KAUST Repository

    Mostert, W.; Pullin, D. I.; Wheatley, V.; Samtaney, Ravi

    2017-01-01

    We present numerical simulations of ideal magnetohydrodynamics showing suppression of the Richtmyer-Meshkov instability in spherical implosions in the presence of an octahedrally symmetric magnetic field. This field configuration is of interest owing to its high degree of spherical symmetry in comparison with previously considered dihedrally symmetric fields. The simulations indicate that the octahedral field suppresses the instability comparably to the other previously considered candidate fields for light-heavy interface accelerations while retaining a highly symmetric underlying flow even at high field strengths. With this field, there is a reduction in the root-mean-square perturbation amplitude of up to approximately 50% at representative time under the strongest field tested while maintaining a homogeneous suppression pattern compared to the other candidate fields.

  4. Magnetohydrodynamic implosion symmetry and suppression of Richtmyer-Meshkov instability in an octahedrally symmetric field

    KAUST Repository

    Mostert, W.

    2017-01-27

    We present numerical simulations of ideal magnetohydrodynamics showing suppression of the Richtmyer-Meshkov instability in spherical implosions in the presence of an octahedrally symmetric magnetic field. This field configuration is of interest owing to its high degree of spherical symmetry in comparison with previously considered dihedrally symmetric fields. The simulations indicate that the octahedral field suppresses the instability comparably to the other previously considered candidate fields for light-heavy interface accelerations while retaining a highly symmetric underlying flow even at high field strengths. With this field, there is a reduction in the root-mean-square perturbation amplitude of up to approximately 50% at representative time under the strongest field tested while maintaining a homogeneous suppression pattern compared to the other candidate fields.

  5. Nursing students’ satisfaction about their field of study

    Directory of Open Access Journals (Sweden)

    ASHRAFALSADAT HAKIM

    2014-04-01

    Full Text Available Introduction: Nowadays students’ opinion is considered as a necessary factor to evaluate quality in universities. This study was performed to evaluate the nursing students’ satisfaction about their field of study. Methods: The research population in this study consists of all the students of nursing studying at the second to fourth year of university (72 students. The data were collected from all the studied population. Data collection instrument was a research questionnaire. In this cross-sectional research, nursing students’ satisfaction (72 students in 6 major topics (situation of educational environment, situation of clinical environment, trainers, social image, relation to colleagues and management was studied. The data were analyzed in SPSS version 14, using quantitative variables and descriptive statistics including frequency distribution tables and diagrams. Results: The findings indicated that 83.3% of the students had little satisfaction as to the situation of educational environment, 47.2% about situation of clinical environment, 41.7% concerning the theoretical educational method by professors, and 41.7% as to the method of clinical education by clinical trainers. Also 47.2% were not that satisfied with the method of evaluation by the school professors, 80.6% with the method of relationship with colleagues and also 62.5% with the nursing social image. Moreover, findings indicated that 33.3% of the participants in this research were dissatisfied with the method of evaluation by clinical trainers and 50% with the method of nursing management. Conclusion: In the present study, most students had little satisfaction concerning their field of study. So it is necessary to make an attempt for continuous development of quality services.

  6. Learning receptive fields using predictive feedback.

    Science.gov (United States)

    Jehee, Janneke F M; Rothkopf, Constantin; Beck, Jeffrey M; Ballard, Dana H

    2006-01-01

    Previously, it was suggested that feedback connections from higher- to lower-level areas carry predictions of lower-level neural activities, whereas feedforward connections carry the residual error between the predictions and the actual lower-level activities [Rao, R.P.N., Ballard, D.H., 1999. Nature Neuroscience 2, 79-87.]. A computational model implementing the hypothesis learned simple cell receptive fields when exposed to natural images. Here, we use predictive feedback to explain tuning properties in medial superior temporal area (MST). We implement the hypothesis using a new, biologically plausible, algorithm based on matching pursuit, which retains all the features of the previous implementation, including its ability to efficiently encode input. When presented with natural images, the model developed receptive field properties as found in primary visual cortex. In addition, when exposed to visual motion input resulting from movements through space, the model learned receptive field properties resembling those in MST. These results corroborate the idea that predictive feedback is a general principle used by the visual system to efficiently encode natural input.

  7. Autonomous dynamic obstacle avoidance for bacteria-powered microrobots (BPMs with modified vector field histogram.

    Directory of Open Access Journals (Sweden)

    Hoyeon Kim

    Full Text Available In order to broaden the use of microrobots in practical fields, autonomous control algorithms such as obstacle avoidance must be further developed. However, most previous studies of microrobots used manual motion control to navigate past tight spaces and obstacles while very few studies demonstrated the use of autonomous motion. In this paper, we demonstrated a dynamic obstacle avoidance algorithm for bacteria-powered microrobots (BPMs using electric field in fluidic environments. A BPM consists of an artificial body, which is made of SU-8, and a high dense layer of harnessed bacteria. BPMs can be controlled using externally applied electric fields due to the electrokinetic property of bacteria. For developing dynamic obstacle avoidance for BPMs, a kinematic model of BPMs was utilized to prevent collision and a finite element model was used to characteristic the deformation of an electric field near the obstacle walls. In order to avoid fast moving obstacles, we modified our previously static obstacle avoidance approach using a modified vector field histogram (VFH method. To validate the advanced algorithm in experiments, magnetically controlled moving obstacles were used to intercept the BPMs as the BPMs move from the initial position to final position. The algorithm was able to successfully guide the BPMs to reach their respective goal positions while avoiding the dynamic obstacles.

  8. 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

  9. Urban Dispersion Program Overview and MID05 Field Study Summary

    Energy Technology Data Exchange (ETDEWEB)

    Allwine, K Jerry; Flaherty, Julia E.

    2007-07-31

    The Urban Dispersion Program (UDP) was a 4-year project (2004–2007) funded by the U.S. Department of Homeland Security with additional support from the Defense Threat Reduction Agency. The U.S. Environmental Protection Agency (EPA) also contributed to UDP through funding a human-exposure component of the New York City (NYC) field studies in addition to supporting an EPA scientist in conducting modeling studies of NYC. The primary goal of UDP was to improve the scientific understanding of the flow and diffusion of airborne contaminants through and around the deep street canyons of NYC. The overall UDP project manager and lead scientist was Dr. Jerry Allwine of Pacific Northwest National Laboratory. UDP had several accomplishments that included conducting two tracer and meteorological field studies in Midtown Manhattan.

  10. The prevalence of previous self-harm amongst self-poisoning patients in Sri Lanka

    DEFF Research Database (Denmark)

    Mohamed, Fahim; Perera, Aravinda; Wijayaweera, Kusal

    2011-01-01

    BACKGROUND: One of the most important components of suicide prevention strategies is to target people who repeat self-harm as they are a high risk group. However, there is some evidence that the incidence of repeat self-harm is lower in Asia than in the West. The objective of this study...... was to investigate the prevalence of previous self-harm among a consecutive series of self-harm patients presenting to hospitals in rural Sri Lanka. METHOD: Six hundred and ninety-eight self-poisoning patients presenting to medical wards at two hospitals in Sri Lanka were interviewed about their previous episodes...... of self-harm. RESULTS: Sixty-one (8.7%, 95% CI 6.7-11%) patients reported at least one previous episode of self-harm [37 (10.7%) male, 24 (6.8%) female]; only 19 (2.7%, 95% CI 1.6-4.2%) patients had made more than one previous attempt. CONCLUSION: The low prevalence of previous self-harm is consistent...

  11. EDUCATIONAL TECHNOLOGY IN PRACTICE Research and Practical Case Studies from the Field

    Directory of Open Access Journals (Sweden)

    Reviewed by Ozden SAHIN-IZMIRLI

    2010-10-01

    Full Text Available The book starts with an explanation of the reason why the terms found in the book are sometimes used in place of each other. The editors stated that when technological tools are used to establish an effective and productive study process in education, the concept of learning technology is used instead of educational technology. The editors of the book considers the field as complex and vague in terms of the fact that the meanings of the concepts are close to each other in the field of educational technology and that the field provides an opportunity for inter-disciplinary studies. However, according to the editors, this vagueness and complexity shows the superiority of the field. This superiority is explained with the fact that the field of educational technology requires upper-level skills of problem solving and critical thinking and that it presents a multi-dimensional and inter-disciplinary study field. The book was edited by Wanjira Kinuthia and Steward Marshall. Wanjira Kinuthia, an assistant professor at Georgia State University, works in the Department of Middle-Secondary Education and Instructional Technology. Steward Marshall, a professor at the University of the West Indies, is the director of the Distance Education Centre. The book includes five sections and 21 chapters. These sections are “Materials, Methods, and Modalities”, “Technology Implementation and Integration Issues”, “Student Engagement and Learning”, “Building Capacity”, “Using Technology for Performance Improvement and Productivity Enhancement”.

  12. Sunburn and sun-protective behaviors among adults with and without previous nonmelanoma skin cancer (NMSC): A population-based study.

    Science.gov (United States)

    Fischer, Alexander H; Wang, Timothy S; Yenokyan, Gayane; Kang, Sewon; Chien, Anna L

    2016-08-01

    Individuals with previous nonmelanoma skin cancer (NMSC) are at increased risk for subsequent skin cancer, and should therefore limit ultraviolet exposure. We sought to determine whether individuals with previous NMSC engage in better sun protection than those with no skin cancer history. We pooled self-reported data (2005 and 2010 National Health Interview Surveys) from US non-Hispanic white adults (758 with and 34,161 without previous NMSC). We calculated adjusted prevalence odds ratios (aPOR) and 95% confidence intervals (CI), taking into account the complex survey design. Individuals with previous NMSC versus no history of NMSC had higher rates of frequent use of shade (44.3% vs 27.0%; aPOR 1.41; 95% CI 1.16-1.71), long sleeves (20.5% vs 7.7%; aPOR 1.55; 95% CI 1.21-1.98), a wide-brimmed hat (26.1% vs 10.5%; aPOR 1.52; 95% CI 1.24-1.87), and sunscreen (53.7% vs 33.1%; aPOR 2.11; 95% CI 1.73-2.59), but did not have significantly lower odds of recent sunburn (29.7% vs 40.7%; aPOR 0.95; 95% CI 0.77-1.17). Among those with previous NMSC, recent sunburn was inversely associated with age, sun avoidance, and shade but not sunscreen. Self-reported cross-sectional data and unavailable information quantifying regular sun exposure are limitations. Physicians should emphasize sunburn prevention when counseling patients with previous NMSC, especially younger adults, focusing on shade and sun avoidance over sunscreen. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  13. CSEM-steel hybrid wiggler/undulator magnetic field studies

    International Nuclear Information System (INIS)

    Halbach, K.; Hoyer, E.; Marks, S.; Plate, D.; Shuman, D.

    1985-05-01

    Current design of permanent magnet wiggler/undulators use either pure charge sheet equivalent material (CSEM) or the CSEM-Steel hybrid configuration. Hybrid configurations offer higher field strength at small gaps, field distributions dominated by the pole surfaces and pole tuning. Nominal performance of the hybrid is generally predicted using a 2-D magnetic design code neglecting transverse geometry. Magnetic measurements are presented showing transverse configuration influence on performance, from a combination of models using CSEMs, REC (H/sub c/ = 9.2 kOe) and NdFe (H/sub c/ = 10.7 kOe), different pole widths and end configurations. Results show peak field improvement using NdFe in place of REC in identical models, gap peak field decrease with pole width decrease (all results less than computed 2-D fields), transverse gap field distributions, and importance of CSEM material overhanging the poles in the transverse direction for highest gap fields

  14. Effect of Previous Irradiation on Vascular Thrombosis of Microsurgical Anastomosis: A Preclinical Study in Rats

    Science.gov (United States)

    Gallardo-Calero, Irene; López-Fernández, Alba; Romagosa, Cleofe; Vergés, Ramona; Aguirre-Canyadell, Marius; Soldado, Francisco; Velez, Roberto

    2016-01-01

    Background: The objective of the present investigation was to compare the effect of neoadjuvant irradiation on the microvascular anastomosis in cervical bundle using an experimental model in rats. Methods: One hundred forty male Sprague–Dawley rats were allocated into 4 groups: group I, control, arterial microanastomosis; group II, control, venous microanastomosis; group III, arterial microanastomosis with previous irradiation (20 Gy); and group IV, venous microanastomosis with previous irradiation (20 Gy). Clinical parameters, technical values of anastomosis, patency, and histopathological parameters were evaluated. Results: Irradiated groups (III and IV) and vein anastomosis groups (II and IV) showed significantly increased technical difficulties. Group IV showed significantly reduced patency rates (7/35) when compared with the control group (0/35). Radiotherapy significantly decreased the patency rates of the vein (7/35) when compared with the artery (1/35). Groups III and IV showed significantly reduced number of endothelial cells and also showed the presence of intimal thickening and adventitial fibrosis as compared with the control group. Conclusion: Neoadjuvant radiotherapy reduces the viability of the venous anastomosis in a preclinical rat model with a significant increase in the incidence of vein thrombosis. PMID:27975009

  15. Recovery of visual-field defects after occipital lobe infarction: a perimetric study.

    Science.gov (United States)

    Çelebisoy, Mehmet; Çelebisoy, Neşe; Bayam, Ece; Köse, Timur

    2011-06-01

    To assess the temporal course of homonymous visual-field defects due to occipital lobe infarction, by using automated perimetry. 32 patients with ischaemic infarction of the occipital lobe were studied prospectively, using a Humphrey Visual Field Analyser II. The visual field of each eye was divided into central, paracentral and peripheral zones. The mean visual sensitivity of each zone was calculated and used for the statistical analysis. The results of the initial examination, performed within 2 weeks of stroke, were compared with the results of the sixth-month control. The lesions were assigned to the localisations, optic radiation, striate cortex, occipital pole and occipital convexity, by MRI. A statistically significant improvement was noted, especially for the lower quadrants. Lesions of the occipital pole and convexity were not significantly associated with visual-field recovery. However, involvement of the striate cortex and extensive lesions involving all the areas studied was significantly associated with poor prognosis. Homonymous visual-field defects in our patients improved within 6 months. Restoration of the lower quadrants and especially the peripheral zones was noted. Incomplete damage to the striate cortex, which has a varying pattern of vascular supply, could explain this finding. Magnification factor theory, which is the increment of the receptive-field size of striate cortex cells with visual-field eccentricity, may explain the more significant improvement in the peripheral zones.

  16. High-field magnetization of rare-earth ions in scandium

    DEFF Research Database (Denmark)

    Roeland, L. W.; Touborg, P.

    1978-01-01

    The magnetic moments of Tb, Dy, or Er ions in dilute Sc single-crystal alloys have been measured in fields up to 280 × 105 A/m (350 kOe). The Zeeman energies in this high field are comparable to the total crystal-field splittings. This gives rise to characteristic features in the magnetization cu...... curves. The crystal-field parameters obtained previously from experiments in low fields and the Zeeman interaction give a satisfactory quantitative acount of the experimental results....

  17. Vector fields and differential operators: noncommutative case

    International Nuclear Information System (INIS)

    Borowiec, A.

    1997-01-01

    A notion of Cartan pairs as an analogy of vector fields in the realm of noncommutative geometry has been proposed previously. In this paper an outline is given of the construction of a noncommutative analogy of the algebra of differential operators as well as its (algebraic) Fock space realization. Co-universal vector fields and covariant derivatives will also be discussed

  18. Geometry of nutrition in field studies: an illustration using wild primates.

    Science.gov (United States)

    Raubenheimer, David; Machovsky-Capuska, Gabriel E; Chapman, Colin A; Rothman, Jessica M

    2015-01-01

    Nutritional geometry has shown the benefits of viewing nutrition in a multidimensional context, in which foraging is viewed as a process of balancing the intake and use of multiple nutrients. New insights into nutrient regulation have been generated in studies performed in a laboratory context, where accurate measures of amounts (e.g. eaten, converted to body mass, excreted) can be made and analysed using amounts-based nutritional geometry. In most field situations, however, proportional compositions (e.g. of foods, diets, faeces) are the only measures readily available, and in some cases are more relevant to the problem at hand. For this reason, a complementary geometric method was recently introduced for analysing multi-dimensional data on proportional compositions in nutritional studies, called the right-angled mixture triangle (RMT). We use literature data from field studies of primates to demonstrate how the RMT can provide insight into a variety of important concepts in nutritional ecology. We first compare the compositions of foods, using as an example primate milks collected in both the wild and the laboratory. We next compare the diets of different species of primates from the same habitat and of the same species (mountain gorillas) from two distinct forests. Subsequently, we model the relationships between the composition of gorilla diets in these two habitats and the foods that comprise these diets, showing how such analyses can provide evidence for active nutrient-specific regulation in a field context. We provide a framework to relate concepts developed in laboratory studies with field-based studies of nutrition.

  19. Occupational exposure to extremely low-frequency magnetic fields and risk for central nervous system disease

    DEFF Research Database (Denmark)

    Pedersen, Camilla; Poulsen, Aslak Harbo; Rod, Naja Hulvej

    2017-01-01

    Purpose: Evidence of whether exposure to extremely low-frequency magnetic fields (ELF-MF) is related to central nervous system diseases is inconsistent. This study updates a previous study of the incidence of such diseases in a large cohort of Danish utility workers by almost doubling the period...

  20. Coproduct and star product in field theories on Lie-algebra noncommutative space-times

    International Nuclear Information System (INIS)

    Amelino-Camelia, Giovanni; Arzano, Michele

    2002-01-01

    We propose a new approach to field theory on κ-Minkowski noncommutative space-time, a popular example of Lie-algebra space-time. Our proposal is essentially based on the introduction of a star product, a technique which is proving to be very fruitful in analogous studies of canonical noncommutative space-times, such as the ones recently found to play a role in the description of certain string-theory backgrounds. We find to be incorrect the expectation, previously reported in the literature, that the lack of symmetry of the κ-Poincare coproduct should lead to interaction vertices that are not symmetric under exchanges of the momenta of identical particles entering the relevant processes. We show that in κ-Minkowski the coproduct and the star product must indeed treat momenta in a nonsymmetric way, but the overall structure of interaction vertices is symmetric under exchange of identical particles. We also show that in κ-Minkowski field theories it is convenient to introduce the concepts of 'planar' and 'nonplanar' Feynman loop diagrams, again in close analogy with the corresponding concepts previously introduced in the study of field theories in canonical noncommutative space-times

  1. A Comprehensive Model of the Near-Earth Magnetic Field. Phase 3

    Science.gov (United States)

    Sabaka, Terence J.; Olsen, Nils; Langel, Robert A.

    2000-01-01

    The near-Earth magnetic field is due to sources in Earth's core, ionosphere, magnetosphere, lithosphere, and from coupling currents between ionosphere and magnetosphere and between hemispheres. Traditionally, the main field (low degree internal field) and magnetospheric field have been modeled simultaneously, and fields from other sources modeled separately. Such a scheme, however, can introduce spurious features. A new model, designated CMP3 (Comprehensive Model: Phase 3), has been derived from quiet-time Magsat and POGO satellite measurements and observatory hourly and annual means measurements as part of an effort to coestimate fields from all of these sources. This model represents a significant advancement in the treatment of the aforementioned field sources over previous attempts, and includes an accounting for main field influences on the magnetosphere, main field and solar activity influences on the ionosphere, seasonal influences on the coupling currents, a priori characterization of ionospheric and magnetospheric influence on Earth-induced fields, and an explicit parameterization and estimation of the lithospheric field. The result of this effort is a model whose fits to the data are generally superior to previous models and whose parameter states for the various constituent sources are very reasonable.

  2. Ørsted Initial Field Model

    DEFF Research Database (Denmark)

    Olsen, Nils; Holme, R.; Hulot, G.

    2000-01-01

    Magnetic measurements taken by the Orsted satellite during geomagnetic quiet conditions around January 1, 2000 have been used to derive a spherical harmonic model of the Earth's magnetic field for epoch 2000.0. The maximum degree and order of the model is 19 for internal, and 2 for external, source...... fields; however, coefficients above degree 14 may not be robust. Such a detailed model exists for only one previous epoch, 1980. Achieved rms misfit is ... to the Orsted mission, this model supercedes IGRF 2000....

  3. Study of electric field pulsation in helical plasmas

    International Nuclear Information System (INIS)

    Toda, S; Itoh, K

    2011-01-01

    A model for the experimental results of the periodic oscillation of the electric field, so-called the electric field pulsation, observed in the Compact Helical Device (Fujisawa et al 1998 Phys. Rev. Lett. 81 2256) and the Large Helical Device (Shimizu et al 2010 Plasma Fusion Res. 5 S1015) is presented. A self-generated oscillation of the radial electric field is shown as the simulation result in helical plasmas. The reduction of the anomalous transport diffusivity in the core region is observed due to the strong shear of the radial electric field when the positive electric field is shown in the core region in the periodic oscillation of E r . Two different time scales are found in the self-generated oscillation, which are the transport time scale and the fast time scale at the transition of the radial electric field. This oscillation because of the hysteresis characteristic is attributed to the electric field pulsation observed in helical plasmas. The parameter region of the condition for the self-generated oscillation is derived. It is shown that the multiple solutions of the radial electric field for the ambipolar condition are necessary but not sufficient for obtaining the self-generated oscillation.

  4. Conducting field studies for testing pesticide leaching models

    Science.gov (United States)

    Smith, Charles N.; Parrish, Rudolph S.; Brown, David S.

    1990-01-01

    A variety of predictive models are being applied to evaluate the transport and transformation of pesticides in the environment. These include well known models such as the Pesticide Root Zone Model (PRZM), the Risk of Unsaturated-Saturated Transport and Transformation Interactions for Chemical Concentrations Model (RUSTIC) and the Groundwater Loading Effects of Agricultural Management Systems Model (GLEAMS). The potentially large impacts of using these models as tools for developing pesticide management strategies and regulatory decisions necessitates development of sound model validation protocols. This paper offers guidance on many of the theoretical and practical problems encountered in the design and implementation of field-scale model validation studies. Recommendations are provided for site selection and characterization, test compound selection, data needs, measurement techniques, statistical design considerations and sampling techniques. A strategy is provided for quantitatively testing models using field measurements.

  5. Near field studies within the SKB 91 Project

    International Nuclear Information System (INIS)

    Widen, H.; Bengtsson, A.; Grundfelt, B.

    1991-06-01

    A number of near field studies was preformed during the early part of the SKB91 project. This report summaries this work and includes: - Simulation of the steady release from the near field with different time for canister penetration. - Simulation of the release from a repository with 5300 canisters with different penetration times for different parts of the canisters due to manufacturing error, glaciations, inner over pressure and corrosion. - Calculation with a numerical model of the transient release of the instantaneously dissolvable species and the effect of different boundary conditions both at the canister/bentonite and the bentonite/rock interface. - Description of the implementation of a resistance network model for the calculation of the steady state transport resistances in the different pathways from the canisters. - Comparison of two analytical models for the calculation of the release of the instantaneously dissolvable species. (au)

  6. A cross-sectional study of tuberculosis drug resistance among previously treated patients in a tertiary hospital in Accra, Ghana: public health implications of standardized regimens.

    Science.gov (United States)

    Forson, Audrey; Kwara, Awewura; Kudzawu, Samuel; Omari, Michael; Otu, Jacob; Gehre, Florian; de Jong, Bouke; Antonio, Martin

    2018-04-02

    Mycobacterium tuberculosis drug resistance is a major challenge to the use of standardized regimens for tuberculosis (TB) therapy, especially among previously treated patients. We aimed to investigate the frequency and pattern of drug resistance among previously treated patients with smear-positive pulmonary tuberculosis at the Korle-Bu Teaching Hospital Chest Clinic, Accra. This was a cross-sectional survey of mycobacterial isolates from previously treated patients referred to the Chest Clinic Laboratory between October 2010 and October 2013. The Bactec MGIT 960 system for mycobactrerial culture and drug sensitivity testing (DST) was used for sputum culture of AFB smear-positive patients with relapse, treatment failure, failure of smear conversion, or default. Descriptive statistics were used to summarize patient characteristics, and frequency and patterns of drug resistance. A total of 112 isolates were studied out of 155 from previously treated patients. Twenty contaminated (12.9%) and 23 non-viable isolates (14.8%) were excluded. Of the 112 studied isolates, 53 (47.3%) were pan-sensitive to all first-line drugs tested Any resistance (mono and poly resistance) to isoniazid was found in 44 isolates (39.3%) and any resistance to streptomycin in 43 (38.4%). Thirty-one (27.7%) were MDR-TB. Eleven (35.5%) out of 31 MDR-TB isolates were pre-XDR. MDR-TB isolates were more likely than non-MDR isolates to have streptomycin and ethambutol resistance. The main findings of this study were the high prevalence of MDR-TB and streptomycin resistance among previously treated TB patients, as well as a high prevalence of pre-XDR-TB among the MDR-TB patients, which suggest that first-line and second-line DST is essential to aid the design of effective regimens for these groups of patients in Ghana.

  7. Study of the influence of the orientation of a 50-Hz magnetic field on fetal exposure using polynomial chaos decomposition.

    Science.gov (United States)

    Liorni, Ilaria; Parazzini, Marta; Fiocchi, Serena; Ravazzani, Paolo

    2015-05-27

    Human exposure modelling is a complex topic, because in a realistic exposure scenario, several parameters (e.g., the source, the orientation of incident fields, the morphology of subjects) vary and influence the dose. Deterministic dosimetry, so far used to analyze human exposure to electromagnetic fields (EMF), is highly time consuming if the previously-mentioned variations are considered. Stochastic dosimetry is an alternative method to build analytical approximations of exposure at a lower computational cost. In this study, it was used to assess the influence of magnetic flux density (B) orientation on fetal exposure at 50 Hz by polynomial chaos (PC). A PC expansion of induced electric field (E) in each fetal tissue at different gestational ages (GA) was built as a function of B orientation. Maximum E in each fetal tissue and at each GA was estimated for different exposure configurations and compared with the limits of the International Commission of Non-Ionising Radiation Protection (ICNIRP) Guidelines 2010. PC theory resulted in an efficient tool to build accurate approximations of E in each fetal tissue. B orientation strongly influenced E, with a variability across tissues from 10% to 43% with respect to the mean value. However, varying B orientation, maximum E in each fetal tissue was below the limits of ICNIRP 2010 at all GAs.

  8. Field-induced transitions in DySb

    International Nuclear Information System (INIS)

    Brun, T.O.; Lander, G.H.; Korty, F.W.; Kouvel, J.S.

    1974-01-01

    The NaCl-structured compound DySb, which in zero field transforms abruptly at T/sub N/ approximately 9.5 0 K to a Type-II antiferromagnetic (A) state with a nearly tetragonal lattice distortion, was previously found to exhibit rapid field-induced changes in magnetization at 1.5 0 K. The field-induced transitions in a DySb crystal have been studied by neutron diffraction and magnetization measurements in fields up to approximately 60 kOe applied parallel to each of the principal axes. In the broken bracket 100 broken bracket case, the transition from the A to an intermediate ferrimagnetic (Q) state is first-order at 4.2 0 K (critical field H/sub c/ approximately 21 kOe) but is continuous from approximately 6 0 K up to T/sub N/: as H/sub c/ → 0. The Q-to-paramagnetic (P) transition is rapid but continuous at 4.2 0 K (H/sub c/ approximately 40 kOe) and becomes broad as T/sub N/ is approached. In the broken bracket 110 broken bracket case the A-to-Q transition remains essentially first-order from 4.2 0 K (H/sub c/ approximately 15 kOe) up to T/sub N/; above T/sub N/ rapid P-to-Q transitions occur at very high fields. The magnetic structure of the Q state is found to be that of HoP. (U.S.)

  9. Localization of vector field on dynamical domain wall

    Directory of Open Access Journals (Sweden)

    Masafumi Higuchi

    2017-03-01

    Full Text Available In the previous works (arXiv:1202.5375 and arXiv:1402.1346, the dynamical domain wall, where the four dimensional FRW universe is embedded in the five dimensional space–time, has been realized by using two scalar fields. In this paper, we consider the localization of vector field in three formulations. The first formulation was investigated in the previous paper (arXiv:1510.01099 for the U(1 gauge field. In the second formulation, we investigate the Dvali–Shifman mechanism (arXiv:hep-th/9612128, where the non-abelian gauge field is confined in the bulk but the gauge symmetry is spontaneously broken on the domain wall. In the third formulation, we investigate the Kaluza–Klein modes coming from the five dimensional graviton. In the Randall–Sundrum model, the graviton was localized on the brane. We show that the (5,μ components (μ=0,1,2,3 of the graviton are also localized on the domain wall and can be regarded as the vector field on the domain wall. There are, however, some corrections coming from the bulk extra dimension if the domain wall universe is expanding.

  10. The CHAOS-4 Geomagnetic Field Model

    DEFF Research Database (Denmark)

    Olsen, Nils; Finlay, Chris; Lühr, H.

    We present CHAOS-4, a new version in the CHAOS model series, which aims at describing the Earth's magnetic field with high spatial resolution (terms up to spherical degree n=90 for the crustal field, and up to n=16 for the time-varying core field are robustly determined) and high temporal...... between the coordinate systems of the vector magnetometer and of the star sensor providing attitude information). The final CHAOS-4 model is derived by merging two sub-models: its low-degree part has been obtained using similar model parameterization and data sets as used for previous CHAOS models (but...

  11. Treatment planning for SBRT using automated field delivery: A case study

    International Nuclear Information System (INIS)

    Ritter, Timothy A.; Owen, Dawn; Brooks, Cassandra M.; Stenmark, Matthew H.

    2015-01-01

    Stereotactic body radiation therapy (SBRT) treatment planning and delivery can be accomplished using a variety of techniques that achieve highly conformal dose distributions. Herein, we describe a template-based automated treatment field approach that enables rapid delivery of more than 20 coplanar fields. A case study is presented to demonstrate how modest adaptations to traditional SBRT planning can be implemented to take clinical advantage of this technology. Treatment was planned for a left-sided lung lesion adjacent to the chest wall using 25 coplanar treatment fields spaced at 11° intervals. The plan spares the contralateral lung and is in compliance with the conformality standards set forth in Radiation Therapy and Oncology Group protocol 0915, and the dose tolerances found in the report of the American Association of Physicists in Medicine Task Group 101. Using a standard template, treatment planning was accomplished in less than 20 minutes, and each 10 Gy fraction was delivered in approximately 5.4 minutes. For those centers equipped with linear accelerators capable of automated treatment field delivery, the use of more than 20 coplanar fields is a viable SBRT planning approach and yields excellent conformality and quality combined with rapid planning and treatment delivery. Although the case study discusses a laterally located lung lesion, this technique can be applied to centrally located tumors with similar results

  12. Comparison of Cellulose Iβ Simulations with Three Carbohydrate Force Fields.

    Science.gov (United States)

    Matthews, James F; Beckham, Gregg T; Bergenstråhle-Wohlert, Malin; Brady, John W; Himmel, Michael E; Crowley, Michael F

    2012-02-14

    Molecular dynamics simulations of cellulose have recently become more prevalent due to increased interest in renewable energy applications, and many atomistic and coarse-grained force fields exist that can be applied to cellulose. However, to date no systematic comparison between carbohydrate force fields has been conducted for this important system. To that end, we present a molecular dynamics simulation study of hydrated, 36-chain cellulose Iβ microfibrils at room temperature with three carbohydrate force fields (CHARMM35, GLYCAM06, and Gromos 45a4) up to the near-microsecond time scale. Our results indicate that each of these simulated microfibrils diverge from the cellulose Iβ crystal structure to varying degrees under the conditions tested. The CHARMM35 and GLYCAM06 force fields eventually result in structures similar to those observed at 500 K with the same force fields, which are consistent with the experimentally observed high-temperature behavior of cellulose I. The third force field, Gromos 45a4, produces behavior significantly different from experiment, from the other two force fields, and from previously reported simulations with this force field using shorter simulation times and constrained periodic boundary conditions. For the GLYCAM06 force field, initial hydrogen-bond conformations and choice of electrostatic scaling factors significantly affect the rate of structural divergence. Our results suggest dramatically different time scales for convergence of properties of interest, which is important in the design of computational studies and comparisons to experimental data. This study highlights that further experimental and theoretical work is required to understand the structure of small diameter cellulose microfibrils typical of plant cellulose.

  13. Study on magnetic field mapping within cylindrical center volume of general magnet

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Li; Lee, Sang Jin [Uiduk University, Gyeongju (Korea, Republic of)

    2016-06-15

    For the magnetic field analysis or design, it is important to know the behavior of the magnetic field in an interesting space. Magnetic field mapping becomes a useful tool for the study of magnetic field. In this paper, a numerical way for mapping the magnetic field within the cylindrical center volume of magnet is presented, based on the solution of the Laplace's equation in the cylindrical coordinate system. The expression of the magnetic field can be obtained by the magnetic flux density, which measured in the mapped volume. According to the form of the expression, the measurement points are arranged with the parallel cylindrical line (PCL) method. As example, the magnetic flux density generated by an electron cyclotron resonance ion source (ECRIS) magnet and a quadrupole magnet were mapped using the PCL method, respectively. The mapping results show the PCL arrangement method is feasible and convenience to map the magnetic field within a cylindrical center volume generated by the general magnet.

  14. Study of Electromagnetic Fields on Cellular Systems Study of Electromagnetic Fields on Cellular Systems

    Directory of Open Access Journals (Sweden)

    Sergio Solorio-Meza

    2012-02-01

    Full Text Available Durante las últimas décadas, el interés por explicar el efecto de la radiación no ionizante, como es el caso de los campos electromagnéticos (CEM sobre sistemas celulares ha aumentado considerablemente. En este artículo se describe la interacción que existe entre los CEM y sistemas biológicos. Se discute el efecto de la estimulación electromagnética a diferentes frecuencias e intensidades en cultivos celulares. Resultados preliminares al estimular células de neuroblastomas SK-NSH con campos electromagnéticos de extra baja frecuencia (CEM-EBF, CEM que van del rango de 3 a 30 Hz, indican que se induce un estrés celularque se refleja en variaciones en la expresión de proteínas respecto al grupo de células no estimuladas. En particular, la expresión de las proteínas muestra que los CEM-EBF producen cambios en las proteínas presentes en condiciones normales o basales en las células, es decir, aparecen nuevas proteínas o existe un aumento en la cantidad de ellas.In the last decades the interest to study the effect of non-ionizing radiation, such as the electromagnetic fields (EMF on cellular systems has increased. In this article the interaction between EMF and biological systems is described. An analysis of the effect of the electromagnetic stimulation at different frequencies and intensities on cell cultures is performed. Preliminary results show that the stimulation with extremely low frequency electromagnetic fields (ELF-EMF, EMF from 3 to 30 Hz, on the cellular line of neuroblastomaSK-NSH induces cellular stress. This is reflected by a variation in the proteins expression in comparison with the group of cells no stimulated. In particular, the proteins expression shows that the ELF-EMF produce changes in the current proteins in normal or basal conditionsin the cells, that is, new proteins appear or there is evidence of an increasing in theamount of them.

  15. Can DMCO Detect Visual Field Loss in Neurological Patients? A Secondary Validation Study

    DEFF Research Database (Denmark)

    Olsen, Ane Sophie; Steensberg, Alvilda Thougaard; la Cour, Morten

    2017-01-01

    Unrecognized visual field loss is caused by a range of blinding eye conditions as well as serious brain diseases. The commonest cause of asymptomatic visual field loss is glaucoma. No screening tools have been proven cost-effective. Damato Multifixation Campimetry Online (DMCO), an inexpensive...... online test, has been evaluated as a future cost-beneficial tool to detect glaucoma. To further validate DMCO, this study aimed to test DMCO in a preselected population with neurological visual field loss. Methods : The study design was an evaluation of a diagnostic test. Patients were included...... if they had undergone surgery for epilepsy during 2011-2014, resulting in visual field loss. They were examined with DMCO and results were compared with those obtained with the Humphrey Field Analyzer (30:2 SITA-Fast). DMCO sensitivity and specificity were estimated with 95% confidence intervals. Results...

  16. Magnetic field topology and chemical abundance distributions of the young, rapidly rotating, chemically peculiar star HR 5624

    Science.gov (United States)

    Kochukhov, O.; Silvester, J.; Bailey, J. D.; Landstreet, J. D.; Wade, G. A.

    2017-09-01

    Context. The young, rapidly rotating Bp star HR 5624 (HD 133880) shows an unusually strong non-sinusoidal variability of its longitudinal magnetic field. This behaviour was previously interpreted as the signature of an exceptionally strong, quadrupole-dominated surface magnetic field geometry. Aims: We studied the magnetic field structure and chemical abundance distributions of HR 5624 with the aim to verify the unusual quadrupolar nature of its magnetic field and to investigate correlations between the field topology and chemical spots. Methods: We analysed high-resolution, time series Stokes parameter spectra of HR 5624 with the help of a magnetic Doppler imaging inversion code based on detailed polarised radiative transfer modelling of the line profiles. Results: We refined the stellar parameters, revised the rotational period, and obtained new longitudinal magnetic field measurements. Our magnetic Doppler inversions reveal that the field structure of HR 5624 is considerably simpler and the field strength is much lower than proposed by previous studies. We find a maximum local field strength of 12 kG and a mean field strength of 4 kG, which is about a factor of three weaker than predicted by quadrupolar field models. Our model implies that overall large-scale field topology of HR 5624 is better described as a distorted, asymmetric dipole rather than an axisymmetric quadrupole. The chemical abundance maps of Mg, Si, Ti, Cr, Fe, and Nd obtained in our study are characterised by large-scale, high-contrast abundance patterns. These structures correlate weakly with the magnetic field geometry and, in particular, show no distinct element concentrations in the horizontal field regions predicted by theoretical atomic diffusion calculations. Conclusions: We conclude that the surface magnetic field topology of HR 5624 is not as unusual as previously proposed. Considering these results together with other recent magnetic mapping analyses of early-type stars suggests that

  17. On the convergence of finite state mean-field games through Γ-convergence

    KAUST Repository

    Ferreira, Rita C.; Gomes, Diogo A.

    2014-01-01

    In this study, we consider the long-term convergence (trend toward an equilibrium) of finite state mean-field games using Γ-convergence. Our techniques are based on the observation that an important class of mean-field games can be viewed as the Euler-Lagrange equation of a suitable functional. Therefore, using a scaling argument, one can convert a long-term convergence problem into a Γ-convergence problem. Our results generalize previous results related to long-term convergence for finite state problems. © 2014 Elsevier Inc.

  18. On the convergence of finite state mean-field games through Γ-convergence

    KAUST Repository

    Ferreira, Rita C.

    2014-10-01

    In this study, we consider the long-term convergence (trend toward an equilibrium) of finite state mean-field games using Γ-convergence. Our techniques are based on the observation that an important class of mean-field games can be viewed as the Euler-Lagrange equation of a suitable functional. Therefore, using a scaling argument, one can convert a long-term convergence problem into a Γ-convergence problem. Our results generalize previous results related to long-term convergence for finite state problems. © 2014 Elsevier Inc.

  19. Activation changes in zebra finch (Taeniopygia guttata) brain areas evoked by alterations of the earth magnetic field.

    Science.gov (United States)

    Keary, Nina; Bischof, Hans-Joachim

    2012-01-01

    Many animals are able to perceive the earth magnetic field and to use it for orientation and navigation within the environment. The mechanisms underlying the perception and processing of magnetic field information within the brain have been thoroughly studied, especially in birds, but are still obscure. Three hypotheses are currently discussed, dealing with ferromagnetic particles in the beak of birds, with the same sort of particles within the lagena organs, or describing magnetically influenced radical-pair processes within retinal photopigments. Each hypothesis is related to a well-known sensory organ and claims parallel processing of magnetic field information with somatosensory, vestibular and visual input, respectively. Changes in activation within nuclei of the respective sensory systems have been shown previously. Most of these previous experiments employed intensity enhanced magnetic stimuli or lesions. We here exposed unrestrained zebra finches to either a stationary or a rotating magnetic field of the local intensity and inclination. C-Fos was used as an activity marker to examine whether the two treatments led to differences in fourteen brain areas including nuclei of the somatosensory, vestibular and visual system. An ANOVA revealed an overall effect of treatment, indicating that the magnetic field change was perceived by the birds. While the differences were too small to be significant in most areas, a significant enhancement of activation by the rotating stimulus was found in a hippocampal subdivision. Part of the hyperpallium showed a strong, nearly significant, increase. Our results are compatible with previous studies demonstrating an involvement of at least three different sensory systems in earth magnetic field perception and suggest that these systems, probably less elaborated, may also be found in nonmigrating birds.

  20. Water liquid-vapor interface subjected to various electric fields: A molecular dynamics study

    Science.gov (United States)

    Nikzad, Mohammadreza; Azimian, Ahmad Reza; Rezaei, Majid; Nikzad, Safoora

    2017-11-01

    Investigation of the effects of E-fields on the liquid-vapor interface is essential for the study of floating water bridge and wetting phenomena. The present study employs the molecular dynamics method to investigate the effects of parallel and perpendicular E-fields on the water liquid-vapor interface. For this purpose, density distribution, number of hydrogen bonds, molecular orientation, and surface tension are examined to gain a better understanding of the interface structure. Results indicate enhancements in parallel E-field decrease the interface width and number of hydrogen bonds, while the opposite holds true in the case of perpendicular E-fields. Moreover, perpendicular fields disturb the water structure at the interface. Given that water molecules tend to be parallel to the interface plane, it is observed that perpendicular E-fields fail to realign water molecules in the field direction while the parallel ones easily do so. It is also shown that surface tension rises with increasing strength of parallel E-fields, while it reduces in the case of perpendicular E-fields. Enhancement of surface tension in the parallel field direction demonstrates how the floating water bridge forms between the beakers. Finally, it is found that application of external E-fields to the liquid-vapor interface does not lead to uniform changes in surface tension and that the liquid-vapor interfacial tension term in Young's equation should be calculated near the triple-line of the droplet. This is attributed to the multi-directional nature of the droplet surface, indicating that no constant value can be assigned to a droplet's surface tension in the presence of large electric fields.

  1. Biological treatment process for removing petroleum hydrocarbons from oil field produced waters

    Energy Technology Data Exchange (ETDEWEB)

    Tellez, G.; Khandan, N.

    1995-12-31

    The feasibility of removing petroleum hydrocarbons from oil fields produced waters using biological treatment was evaluated under laboratory and field conditions. Based on previous laboratory studies, a field-scale prototype system was designed and operated over a period of four months. Two different sources of produced waters were tested in this field study under various continuous flow rates ranging from 375 1/D to 1,800 1/D. One source of produced water was an open storage pit; the other, a closed storage tank. The TDS concentrations of these sources exceeded 50,000 mg/l; total n-alkanes exceeded 100 mg/l; total petroleum hydrocarbons exceeded 125 mg/l; and total BTEX exceeded 3 mg/l. Removals of total n-alkanes, total petroleum hydrocarbons, and BTEX remained consistently high over 99%. During these tests, the energy costs averaged $0.20/bbl at 12 bbl/D.

  2. Extensive Field Survey, Laboratory and Greenhouse Studies Reveal Complex Nature of Pseudomonas syringae-Associated Hazelnut Decline in Central Italy.

    Science.gov (United States)

    Lamichhane, Jay Ram; Bartoli, Claudia; Varvaro, Leonardo

    2016-01-01

    Pseudomonas avellanae (Pav) has been reported as the causal agent of bacterial decline and bacterial canker of hazelnut in Italy and Greece, respectively. Both hazelnut diseases were reported to be similar in terms of symptoms, severity and persistence. In this study, we found that both symptomatic and asymptomatic trees in the field were colonized by Pav. Multilocus Sequence Typing (MLST) analysis showed that Pav strains isolated during this study in Italy belong to the P. syringae phylogroup 1 and they are closely related to Pav strains previously isolated in Greece from hazelnut bacterial canker. On the other hand, strains isolated in earlier studies from hazelnut decline in Italy belong to both phylogroup 1 and 2 of P. syringae. Both phylogroup 1 strains of P. syringae from Greece and Italy are different than strains isolated in this study in terms of their capacity to excrete fluorescent pigments on different media. Despite the same plant genotype and cropping practices adopted, the incidence of hazelnut decline ranged from nearly 0 to 91% across our study sites. No disease developed on plants inoculated with Pav through wounding while leaf scar inoculations produced only mild disease symptoms. Based on our results and the previously reported correlation between pedo-climatic conditions and hazelnut decline, we conclude that hazelnut decline in central Italy could be incited by a combination of predisposing (adverse pedo-climatic conditions) and contributing factors (Pav). Because this is a true decline different from "bacterial canker" described in Greece, we refer to it as hazelnut decline (HD).

  3. Extensive Field Survey, Laboratory and Greenhouse Studies Reveal Complex Nature of Pseudomonas syringae-Associated Hazelnut Decline in Central Italy.

    Directory of Open Access Journals (Sweden)

    Jay Ram Lamichhane

    Full Text Available Pseudomonas avellanae (Pav has been reported as the causal agent of bacterial decline and bacterial canker of hazelnut in Italy and Greece, respectively. Both hazelnut diseases were reported to be similar in terms of symptoms, severity and persistence. In this study, we found that both symptomatic and asymptomatic trees in the field were colonized by Pav. Multilocus Sequence Typing (MLST analysis showed that Pav strains isolated during this study in Italy belong to the P. syringae phylogroup 1 and they are closely related to Pav strains previously isolated in Greece from hazelnut bacterial canker. On the other hand, strains isolated in earlier studies from hazelnut decline in Italy belong to both phylogroup 1 and 2 of P. syringae. Both phylogroup 1 strains of P. syringae from Greece and Italy are different than strains isolated in this study in terms of their capacity to excrete fluorescent pigments on different media. Despite the same plant genotype and cropping practices adopted, the incidence of hazelnut decline ranged from nearly 0 to 91% across our study sites. No disease developed on plants inoculated with Pav through wounding while leaf scar inoculations produced only mild disease symptoms. Based on our results and the previously reported correlation between pedo-climatic conditions and hazelnut decline, we conclude that hazelnut decline in central Italy could be incited by a combination of predisposing (adverse pedo-climatic conditions and contributing factors (Pav. Because this is a true decline different from "bacterial canker" described in Greece, we refer to it as hazelnut decline (HD.

  4. Seminal magnetic fields from inflato-electromagnetic inflation

    Energy Technology Data Exchange (ETDEWEB)

    Membiela, Federico Agustin; Bellini, Mauricio [Universidad Nacional de Mar del Plata, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Instituto de Investigaciones Fisicas de Mar del Plata (IFIMAR), Buenos Aires (Argentina)

    2012-10-15

    We extend some previous attempts to explain the origin and evolution of primordial magnetic fields during inflation induced from a 5D vacuum. We show that the usual quantum fluctuations of a generalized 5D electromagnetic field cannot provide us with the desired magnetic seeds. We show that special fields without propagation on the extra non-compact dimension are needed to arrive at appreciable magnetic strengths. We also identify a new magnetic tensor field B{sub ij} in this kind of extra dimensional theory. Our results are in very good agreement with observational requirements, in particular from TeV blazars and CMB radiation limits we see that primordial cosmological magnetic fields should be close to scale invariance. (orig.)

  5. Seminal magnetic fields from inflato-electromagnetic inflation

    Science.gov (United States)

    Membiela, Federico Agustín; Bellini, Mauricio

    2012-10-01

    We extend some previous attempts to explain the origin and evolution of primordial magnetic fields during inflation induced from a 5D vacuum. We show that the usual quantum fluctuations of a generalized 5D electromagnetic field cannot provide us with the desired magnetic seeds. We show that special fields without propagation on the extra non-compact dimension are needed to arrive at appreciable magnetic strengths. We also identify a new magnetic tensor field B ij in this kind of extra dimensional theory. Our results are in very good agreement with observational requirements, in particular from TeV blazars and CMB radiation limits we see that primordial cosmological magnetic fields should be close to scale invariance.

  6. Seminal magnetic fields from inflato-electromagnetic inflation

    International Nuclear Information System (INIS)

    Membiela, Federico Agustin; Bellini, Mauricio

    2012-01-01

    We extend some previous attempts to explain the origin and evolution of primordial magnetic fields during inflation induced from a 5D vacuum. We show that the usual quantum fluctuations of a generalized 5D electromagnetic field cannot provide us with the desired magnetic seeds. We show that special fields without propagation on the extra non-compact dimension are needed to arrive at appreciable magnetic strengths. We also identify a new magnetic tensor field B ij in this kind of extra dimensional theory. Our results are in very good agreement with observational requirements, in particular from TeV blazars and CMB radiation limits we see that primordial cosmological magnetic fields should be close to scale invariance. (orig.)

  7. Conformal generally covariant quantum field theory. The scalar field and its Wick products

    Energy Technology Data Exchange (ETDEWEB)

    Pinamonti, N. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2008-06-15

    In this paper we generalize the construction of generally covariant quantum theories given in [R. Brunetti, K. Fredenhagen, R. Verch, Commun. Math. Phys. 237, 31 (2003)] to encompass the conformal covariant case. After introducing the abstract framework, we discuss the massless conformally coupled Klein Gordon field theory, showing that its quantization corresponds to a functor between two certain categories. At the abstract level, the ordinary fields, could be thought as natural transformations in the sense of category theory. We show that, the Wick monomials without derivatives (Wick powers), can be interpreted as fields in this generalized sense, provided a non trivial choice of the renormalization constants is given. A careful analysis shows that the transformation law of Wick powers is characterized by a weight, and it turns out that the sum of fields with different weights breaks the conformal covariance. At this point there is a difference between the previously given picture due to the presence of a bigger group of covariance. It is furthermore shown that the construction does not depend upon the scale {mu} appearing in the Hadamard parametrix, used to regularize the fields. Finally, we briefly discuss some further examples of more involved fields. (orig.)

  8. Conformal generally covariant quantum field theory. The scalar field and its Wick products

    International Nuclear Information System (INIS)

    Pinamonti, N.

    2008-06-01

    In this paper we generalize the construction of generally covariant quantum theories given in [R. Brunetti, K. Fredenhagen, R. Verch, Commun. Math. Phys. 237, 31 (2003)] to encompass the conformal covariant case. After introducing the abstract framework, we discuss the massless conformally coupled Klein Gordon field theory, showing that its quantization corresponds to a functor between two certain categories. At the abstract level, the ordinary fields, could be thought as natural transformations in the sense of category theory. We show that, the Wick monomials without derivatives (Wick powers), can be interpreted as fields in this generalized sense, provided a non trivial choice of the renormalization constants is given. A careful analysis shows that the transformation law of Wick powers is characterized by a weight, and it turns out that the sum of fields with different weights breaks the conformal covariance. At this point there is a difference between the previously given picture due to the presence of a bigger group of covariance. It is furthermore shown that the construction does not depend upon the scale μ appearing in the Hadamard parametrix, used to regularize the fields. Finally, we briefly discuss some further examples of more involved fields. (orig.)

  9. Combustion Safety Simplified Test Protocol Field Study

    Energy Technology Data Exchange (ETDEWEB)

    Brand, L. [Gas Technology Inst., Des Plaines, IL (United States); Cautley, D. [Gas Technology Inst., Des Plaines, IL (United States); Bohac, D. [Gas Technology Inst., Des Plaines, IL (United States); Francisco, P. [Gas Technology Inst., Des Plaines, IL (United States); Shen, L. [Gas Technology Inst., Des Plaines, IL (United States); Gloss, S. [Gas Technology Inst., Des Plaines, IL (United States)

    2015-11-01

    Combustions safety is an important step in the process of upgrading homes for energy efficiency. There are several approaches used by field practitioners, but researchers have indicated that the test procedures in use are complex to implement and provide too many false positives. Field failures often mean that the house is not upgraded until after remediation or not at all, if not include in the program. In this report the PARR and NorthernSTAR DOE Building America Teams provide a simplified test procedure that is easier to implement and should produce fewer false positives. A survey of state weatherization agencies on combustion safety issues, details of a field data collection instrumentation package, summary of data collected over seven months, data analysis and results are included. The project team collected field data on 11 houses in 2015.

  10. Soil microbial respiration and PICT responses to an industrial and historic lead pollution: a field study.

    Science.gov (United States)

    Bérard, Annette; Capowiez, Line; Mombo, Stéphane; Schreck, Eva; Dumat, Camille; Deola, Frédéric; Capowiez, Yvan

    2016-03-01

    We performed a field investigation to study the long-term impacts of Pb soil contamination on soil microbial communities and their catabolic structure in the context of an industrial site consisting of a plot of land surrounding a secondary lead smelter. Microbial biomass, catabolic profiles, and ecotoxicological responses (PICT) were monitored on soils sampled at selected locations along 110-m transects established on the site. We confirmed the high toxicity of Pb on respirations and microbial and fungal biomasses by measuring positive correlations with distance from the wall factory and negative correlation with total Pb concentrations. Pb contamination also induced changes in microbial and fungal catabolic structure (from carbohydrates to amino acids through carboxylic malic acid). Moreover, PICT measurement allowed to establish causal linkages between lead and its effect on biological communities taking into account the contamination history of the ecosystem at community level. The positive correlation between qCO2 (based on respiration and substrate use) and PICT suggested that the Pb stress-induced acquisition of tolerance came at a greater energy cost for microbial communities in order to cope with the toxicity of the metal. In this industrial context of long-term polymetallic contamination dominated by Pb in a field experiment, we confirmed impacts of this metal on soil functioning through microbial communities, as previously observed for earthworm communities.

  11. A unidirectional subwavelength focusing near-field plate

    Energy Technology Data Exchange (ETDEWEB)

    Imani, Mohammadreza F.; Grbic, Anthony [Radiation Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-01-28

    Near-field plates consist of non-periodically patterned surfaces that can overcome the diffraction limit and confine electromagnetic fields to subwavelength dimensions. Previous near-field plates experimentally demonstrated extreme field tailoring capabilities. However, their performance suffered from radiation/reflection in undesired directions, those other than the subwavelength focus. This issue can limit the practical use of near-field plates. In this paper, we address this issue by designing a unidirectional near-field plate that can form a subwavelength focal pattern, while suppressing the field radiated/reflected in other directions. The design and operation of the proposed unidirectional near-field plate are verified through full-wave simulation. The unidirectional near-field plate may find application in high resolution imaging and probing, high density data storage, and wireless power transfer systems. As an example, its utility as a high resolution probe is demonstrated through full-wave electromagnetic simulation.

  12. The Momotombo Geothermal Field, Nicaragua: Exploration and development case history study

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-07-01

    This case history discusses the exploration methods used at the Momotombo Geothermal Field in western Nicaragua, and evaluates their contributions to the development of the geothermal field models. Subsequent reservoir engineering has not been synthesized or evaluated. A geothermal exploration program was started in Nicaragua in 1966 to discover and delineate potential geothermal reservoirs in western Nicaragua. Exploration began at the Momotombo field in 1970 using geological, geochemical, and geophysical methods. A regional study of thermal manifestations was undertaken and the area on the southern flank of Volcan Momotombo was chosen for more detailed investigation. Subsequent exploration by various consultants produced a number of geotechnical reports on the geology, geophysics, and geochemistry of the field as well as describing production well drilling. Geological investigations at Momotombo included photogeology, field mapping, binocular microscope examination of cuttings, and drillhole correlations. Among the geophysical techniques used to investigate the field sub-structure were: Schlumberger and electromagnetic soundings, dipole mapping and audio-magnetotelluric surveys, gravity and magnetic measurements, frequency domain soundings, self-potential surveys, and subsurface temperature determinations. The geochemical program analyzed the thermal fluids of the surface and in the wells. This report presents the description and results of exploration methods used during the investigative stages of the Momotombo Geothermal Field. A conceptual model of the geothermal field was drawn from the information available at each exploration phase. The exploration methods have been evaluated with respect to their contributions to the understanding of the field and their utilization in planning further development. Our principal finding is that data developed at each stage were not sufficiently integrated to guide further work at the field, causing inefficient use of

  13. The influence of primordial magnetic fields on the spherical collapse model in cosmology

    International Nuclear Information System (INIS)

    Shibusawa, Y.; Ichiki, K.; Kadota, K.

    2014-01-01

    Despite the ever growing observational evidence for the existence of the large scale magnetic fields, their origin and the evolution are not fully understood. If the magnetic fields are of primordial origin, they result in the generation of the secondary matter density perturbations and the previous studies show that such density perturbations enhance the number of dark matter halos. We extend the conventional spherical collapse model by including the Lorentz force which has not been implemented in the previous analysis to study the evolution of density perturbations produced by primordial magnetic fields. The critical over-density δ c characterizing the halo mass function turns out to be a bigger value, δ c ≅ 1.78, than the conventional one δ c ≅ 1.69 for the perturbations evolved only by the gravitational force. The difference in δ c between our model and the fully matter dominated cosmological model is small at a low redshift and, hence, only the high mass tail of the mass function is affected by the magnetic fields. At a high redshift, on the other hand, the difference in δ c becomes large enough to suppress the halo abundance over a wide range of mass scales. The halo abundance is reduced for instance by as large a factor as ∼10 5 at z=9

  14. The pathogenicity of genetic variants previously associated with left ventricular non-compaction

    DEFF Research Database (Denmark)

    Abbasi, Yeganeh; Jabbari, Javad; Jabbari, Reza

    2016-01-01

    BACKGROUND: Left ventricular non-compaction (LVNC) is a rare cardiomyopathy. Many genetic variants have been associated with LVNC. However, the number of the previous LVNC-associated variants that are common in the background population remains unknown. The aim of this study was to provide...... an updated list of previously reported LVNC-associated variants with biologic description and investigate the prevalence of LVNC variants in healthy general population to find false-positive LVNC-associated variants. METHODS AND RESULTS: The Human Gene Mutation Database and PubMed were systematically...... searched to identify all previously reported LVNC-associated variants. Thereafter, the Exome Sequencing Project (ESP) and the Exome Aggregation Consortium (ExAC), that both represent the background population, was searched for all variants. Four in silico prediction tools were assessed to determine...

  15. Design study of the vertical field power supply for JT-60

    International Nuclear Information System (INIS)

    Yabuno, Kohei; Tani, Keiji; Shimada, Ryuichi; Kishimoto, Hiroshi; Yoshida, Hidetoshi

    1977-09-01

    The results of a basic design study of the vertical field power supply for JT-60 (JAERI large tokamak) are described. The objective of the study is to evaluate several types of power supply circuits for fast excitation and control of the vertical field. A design requirement is to produce a rapidly increasing vertical field within accuracy of +-5% around the proper field strength required to center the plasma in the vacuum vessel. The plasma current is assumed to increase at the rate of about 100 MA/sec. To meet the requirement, a maximum voltage of 15 kV is necessary in the current build-up time, while generally relatively low voltage is necessary after the current flattop is reached. A hybrid power supply which consists of a dc power source (a thyristor converter) and an inductive energy storage system is proposed. The maximum voltage of the dc power source is determined as 4 kV from the voltage required in the current flattop time. This is sufficient also in the current build-up time if the dc power source is used together with the inductive energy storage system. (auth.)

  16. Reoperative sentinel lymph node biopsy after previous mastectomy.

    Science.gov (United States)

    Karam, Amer; Stempel, Michelle; Cody, Hiram S; Port, Elisa R

    2008-10-01

    Sentinel lymph node (SLN) biopsy is the standard of care for axillary staging in breast cancer, but many clinical scenarios questioning the validity of SLN biopsy remain. Here we describe our experience with reoperative-SLN (re-SLN) biopsy after previous mastectomy. Review of the SLN database from September 1996 to December 2007 yielded 20 procedures done in the setting of previous mastectomy. SLN biopsy was performed using radioisotope with or without blue dye injection superior to the mastectomy incision, in the skin flap in all patients. In 17 of 20 patients (85%), re-SLN biopsy was performed for local or regional recurrence after mastectomy. Re-SLN biopsy was successful in 13 of 20 patients (65%) after previous mastectomy. Of the 13 patients, 2 had positive re-SLN, and completion axillary dissection was performed, with 1 having additional positive nodes. In the 11 patients with negative re-SLN, 2 patients underwent completion axillary dissection demonstrating additional negative nodes. One patient with a negative re-SLN experienced chest wall recurrence combined with axillary recurrence 11 months after re-SLN biopsy. All others remained free of local or axillary recurrence. Re-SLN biopsy was unsuccessful in 7 of 20 patients (35%). In three of seven patients, axillary dissection was performed, yielding positive nodes in two of the three. The remaining four of seven patients all had previous modified radical mastectomy, so underwent no additional axillary surgery. In this small series, re-SLN was successful after previous mastectomy, and this procedure may play some role when axillary staging is warranted after mastectomy.

  17. The Lathrop Wells volcanic center: Status of field and geochronology studies

    International Nuclear Information System (INIS)

    Crowe, B.; Morley, R.; Wells, S.; Geissman, J.; McDonald, E.; McFadden, L.; Perry, F.; Murrell, M.; Poths, J.; Forman, S.

    1992-01-01

    The purpose of this paper is to describe the status of field and geochronology studies of the Lathrop Wells volcanic center. Our perspective is that it is critical to assess all possible methods for obtaining cross-checking data to resolve chronology and field problems. It is equally important to consider application of the range of chronology methods available in Quaternary geologic research. Such an approach seeks to increase the confidence in data interpretations through obtaining convergence among separate isotopic, radiogenic, and age-correlated methods. Finally, the assumptions, strengths, and weaknesses of each dating method need to be carefully described to facilitate an impartial evaluation of results. The paper is divided into two parts. The first part describes the status of continuing field studies for the volcanic center for this area south of Yucca Mountain, Nevada. The second part presents an overview of the preliminary results of ongoing chronology studies and their constraints on the age and stratigraphy of the Lathrop Wells volcanic center. Along with the chronology data, the assumptions, strengths, and limitations of each methods are discussed

  18. A statistical relationship between the geosynchronous magnetic field and substorm electrojet magnitude

    International Nuclear Information System (INIS)

    Lopez, R.E.; Rosenvinge, T. von

    1993-01-01

    In this paper the authors examine the relationship between geosynchronous magnetic field variations during substorms measured by GOES 5 and the auroral electrojet as measured by AE and Poste de la Baleine. As in previous studies, the authors find that the more taillike the field prior to the local onset, the greater the dipolarization of the field during the substorm. They also find that the greater the deviation of the field from a dipolar configuration, the larger the change in AE during the event. This implies that stronger cross-tail currents prior to the substorm are associated with larger substorm-associated westward electrojets and thus more intense substorms. Previous work has shown that in order to produce the observed taillike fields at geosynchronous altitude, the intense cross-tail current that builds up during the growth phase must be localized in the near-Earth (≤ 10 R E ) region. Since the westward electrojet is the ionospheric leg of the substorm current wedge, this result implies that the substorm-associated westward electrojet is drawn from the near-Earth region. In fact, the authors find that most of the current diversion occurs in the near-Earth magnetotail. Furthermore, they estimate that a diversion about half of the near-Earth cross-tail current can account for the current in the northern and southern westward electrojets associated with the substorm current wedge. 25 refs., 9 figs

  19. Seismic and potential field studies over the East Midlands

    Science.gov (United States)

    Kirk, Wayne John

    A seismic refraction profile was undertaken to investigate the source of an aeromagnetic anomaly located above the Widmerpool Gulf, East Midlands. Ten shots were fired into 51 stations at c. 1.5km spacing in a 70km profile during 41 days recording. The refraction data were processed using standard techniques to improve the data quality. A new filtering technique, known as Correlated Adaptive Noise Cancellation was tested on synthetic data and successfully applied to controlled source and quarry blast data. Study of strong motion data reveals that the previous method of site calibration is invalid. A new calibration technique, known as the Scaled Amplitude method is presented to provide safer charge size estimation. Raytrace modelling of the refraction data and two dimensional gravity interpretation confirms the presence of the Widmerpool Gulf but no support is found for the postulated intrusion. Two dimensional magnetic interpretation revealed that the aeromagnetic anomaly could be modelled with a Carboniferous igneous source. A Lower Palaeozoic refractor with a velocity of 6.0 km/s is identified at a maximum depth of c. 2.85km beneath the Widmerpool Gulf. Carboniferous and post-Carboniferous sediments within the gulf have velocities between 2.6-5.5 km/s with a strong vertical gradient. At the gulf margins, a refractor with a constant velocity of 5.2 km/s is identified as Dinantian limestone. A low velocity layer of proposed unaltered Lower Palaeozoics is identified beneath the limestone at the eastern edge of the Derbyshire Dome. The existence and areal extent of this layer are also determined from seismic reflection data. Image analysis of potential field data, presents a model identifying 3 structural provinces, the Midlands Microcraton, the Welsh and English Caledonides and a central region of complex linears. This model is used to explain the distribution of basement rocks determined from seismic and gravity profiles.

  20. Interferometric study on the mass transfer in cryogenic distillation under magnetic field

    Science.gov (United States)

    Bao, S. R.; Zhang, R. P.; Y Rong, Y.; Zhi, X. Q.; Qiu, L. M.

    2017-12-01

    Cryogenic distillation has long been used for the mass production of industrial gases because of its features of high efficiency, high purity, and capability to produce noble gases. It is of great theoretical and practical significance to explore methods to improve the mass transfer efficiency in cryogenic distillation. The negative correlation between the susceptibility of paramagnetic oxygen and temperature provides a new possibility of comprehensive utilization of boiling point and susceptibility differences in cryogenic distillation. Starting from this concept, we proposed a novel distillation intensifying method by using gradient magnetic field, in which the magnetic forces enhance the transport of the oxygen molecules to the liquid phase in the distillation. In this study, a cryogenic testbed was designed and fabricated to study the diffusion between oxygen and nitrogen under magnetic field. A Mach-Zehnder interferometer was used to visualize the concentration distribution during the diffusion process. The mass transfer characteristics with and without magnetic field, in the chamber filled with the magnetized medium, were systematically studied. The concentration redistribution of oxygen was observed, and the stable stratified diffusion between liquid oxygen and nitrogen was prolonged by the non-uniform magnetic field. The experimental results show that the magnetic field can efficiently influence the mass transfer in cryogenic distillation, which can provide a new mechanism for the optimization of air separation process.

  1. The Effects of College Major and Job Field Congruence on Job Satisfaction

    Science.gov (United States)

    Wolniak, Gregory C.; Pascarella, Ernest T.

    2005-01-01

    This study investigated predictors of job satisfaction and builds on previous research on the effects of bachelor's degree majors and job field congruence on job satisfaction. Data on workers' job experiences in 2001 were matched to those workers' college experiences across 30 institutions and background characteristics up to 25 years earlier.…

  2. Always connected: a longitudinal field study of mobile communication

    NARCIS (Netherlands)

    Peters, O.; Ben Allouch, Soumaya

    2005-01-01

    Twenty-five novice users of a new mobile communication device were closely tracked for a period of three months. The results of this longitudinal field study show that people’s motivations for using mobile communication technology are initially influenced more strongly by their perceptions about the

  3. Subwavelength position measurements with running-wave driving fields

    Energy Technology Data Exchange (ETDEWEB)

    Evers, Joerg [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Qamar, Sajid [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Centre for Quantum Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan)

    2011-08-15

    Subwavelength position measurement of quantum particles is discussed. Our setup is based on a closed-loop driving-field configuration, which enforces a sensitivity of the particle dynamics to the phases of the applied fields. Thus, running wave fields are sufficient, avoiding limitations associated with standing-wave-based localization schemes. Reversing the directions of the driving laser fields switches between different magnification levels for the position determination. This allows us to optimize the localization, and at the same time eliminates the need for additional classical measurements common to all previous localization schemes based on spatial periodicity.

  4. Efficient Incorporation of Markov Random Fields in Change Detection

    DEFF Research Database (Denmark)

    Aanæs, Henrik; Nielsen, Allan Aasbjerg; Carstensen, Jens Michael

    2009-01-01

    of noise, implying that the pixel-wise classifier is also noisy. There is thus a need for incorporating local homogeneity constraints into such a change detection framework. For this modelling task Markov Random Fields are suitable. Markov Random Fields have, however, previously been plagued by lack...

  5. 77 FR 70176 - Previous Participation Certification

    Science.gov (United States)

    2012-11-23

    ... participants' previous participation in government programs and ensure that the past record is acceptable prior... information is designed to be 100 percent automated and digital submission of all data and certifications is... government programs and ensure that the past record is acceptable prior to granting approval to participate...

  6. Abelian Toda field theories on the noncommutative plane

    Science.gov (United States)

    Cabrera-Carnero, Iraida

    2005-10-01

    Generalizations of GL(n) abelian Toda and GL with tilde above(n) abelian affine Toda field theories to the noncommutative plane are constructed. Our proposal relies on the noncommutative extension of a zero-curvature condition satisfied by algebra-valued gauge potentials dependent on the fields. This condition can be expressed as noncommutative Leznov-Saveliev equations which make possible to define the noncommutative generalizations as systems of second order differential equations, with an infinite chain of conserved currents. The actions corresponding to these field theories are also provided. The special cases of GL(2) Liouville and GL with tilde above(2) sinh/sine-Gordon are explicitly studied. It is also shown that from the noncommutative (anti-)self-dual Yang-Mills equations in four dimensions it is possible to obtain by dimensional reduction the equations of motion of the two-dimensional models constructed. This fact supports the validity of the noncommutative version of the Ward conjecture. The relation of our proposal to previous versions of some specific Toda field theories reported in the literature is presented as well.

  7. A New Solution for Einstein Field Equation in General Relativity

    Science.gov (United States)

    Mousavi, Sadegh

    2006-05-01

    There are different solutions for Einstein field equation in general relativity that they have been proposed by different people the most important solutions are Schwarzchild, Reissner Nordstrom, Kerr and Kerr Newmam. However, each one of these solutions limited to special case. I've found a new solution for Einstein field equation which is more complete than all previous ones and this solution contains the previous solutions as its special forms. In this talk I will present my new metric for Einstein field equation and the Christofel symbols and Richi and Rieman tensor components for the new metric that I have calculated them by GR TENSOR software. As a result I will determine the actual movement of black holes which is different From Kerr black hole's movement. Finally this new solution predicts, existence of a new and constant field in the nature (that nobody can found it up to now), so in this talk I will introduce this new field and even I will calculate the amount of this field. SADEGH MOUSAVI, Amirkabir University of Technology.

  8. Edge field emission of large-area single layer graphene

    Energy Technology Data Exchange (ETDEWEB)

    Kleshch, Victor I., E-mail: klesch@polly.phys.msu.ru [Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Bandurin, Denis A. [Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Orekhov, Anton S. [Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); A.V. Shubnikov Institute of Crystallography, RAS, Moscow 119333 (Russian Federation); Purcell, Stephen T. [ILM, Université Claude Bernard Lyon 1 et CNRS, UMR 5586, 69622 Villeurbanne (France); Obraztsov, Alexander N. [Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Department of Physics and Mathematics, University of Eastern Finland, Joensuu 80101 (Finland)

    2015-12-01

    Graphical abstract: - Highlights: • Stable field emission was observed from the edge of large-area graphene on quartz. • A strong hysteresis in current–voltage characteristics was observed. • The hysteresis was explained by mechanical peeling of graphene edge from substrate. • Reversible peeling of graphene edge may be used in microelectromechanical systems. - Abstract: Field electron emission from the edges of large-area (∼1 cm × 1 cm) graphene films deposited onto quartz wafers was studied. The graphene was previously grown by chemical vapour deposition on copper. An extreme enhancement of electrostatic field at the edge of the films with macroscopically large lateral dimensions and with single atom thickness was achieved. This resulted in the creation of a blade type electron emitter, providing stable field emission at low-voltage with linear current density up to 0.5 mA/cm. A strong hysteresis in current–voltage characteristics and a step-like increase of the emission current during voltage ramp up were observed. These effects were explained by the local mechanical peeling of the graphene edge from the quartz substrate by the ponderomotive force during the field emission process. Specific field emission phenomena exhibited in the experimental study are explained by a unique combination of structural, electronic and mechanical properties of graphene. Various potential applications ranging from linear electron beam sources to microelectromechanical systems are discussed.

  9. Tuning bacterial hydrodynamics with magnetic fields

    Science.gov (United States)

    Pierce, C. J.; Mumper, E.; Brown, E. E.; Brangham, J. T.; Lower, B. H.; Lower, S. K.; Yang, F. Y.; Sooryakumar, R.

    2017-06-01

    Magnetotactic bacteria are a group of motile prokaryotes that synthesize chains of lipid-bound, magnetic nanoparticles called magnetosomes. This study exploits their innate magnetism to investigate previously unexplored facets of bacterial hydrodynamics at surfaces. Through use of weak, uniform, external magnetic fields and local, micromagnetic surface patterns, the relative strength of hydrodynamic, magnetic, and flagellar force components is tuned through magnetic control of the bacteria's orientation. The resulting swimming behaviors provide a means to experimentally determine hydrodynamic parameters and offer a high degree of control over large numbers of living microscopic entities. The implications of this controlled motion for studies of bacterial motility near surfaces and for micro- and nanotechnology are discussed.

  10. Group theoretical approach to quantum fields in de Sitter space II. The complementary and discrete series

    International Nuclear Information System (INIS)

    Joung, Euihun; Mourad, Jihad; Parentani, Renaud

    2007-01-01

    We use an algebraic approach based on representations of de Sitter group to construct covariant quantum fields in arbitrary dimensions. We study the complementary and the discrete series which correspond to light and massless fields and which lead new feature with respect to the massive principal series we previously studied (hep-th/0606119). When considering the complementary series, we make use of a non-trivial scalar product in order to get local expressions in the position representation. Based on these, we construct a family of covariant canonical fields parametrized by SU(1, 1)/U(1). Each of these correspond to the dS invariant alpha-vacua. The behavior of the modes at asymptotic times brings another difficulty as it is incompatible with the usual definition of the in and out vacua. We propose a generalized notion of these vacua which reduces to the usual conformal vacuum in the conformally massless limit. When considering the massless discrete series we find that no covariant field obeys the canonical commutation relations. To further analyze this singular case, we consider the massless limit of the complementary scalar fields we previously found. We obtain canonical fields with a deformed representation by zero modes. The zero modes have a dS invariant vacuum with singular norm. We propose a regularization by a compactification of the scalar field and a dS invariant definition of the vertex operators. The resulting two-point functions are dS invariant and have a universal logarithmic infrared divergence

  11. Annual tendency of research papers used ICR mice as experimental animals in biomedical research fields

    OpenAIRE

    Kim, Ji Eun; Nam, Jung Hoon; Cho, Joon Young; Kim, Kil Soo; Hwang, Dae Youn

    2017-01-01

    Institute of Cancer Research (ICR) mice have been widely used in various research fields including toxicology, oncology, pharmacology, and pharmaceutical product safety testing for decades. However, annual tendency of research papers involving ICR mice in various biomedical fields has not been previously analyzed. In this study, we examined the numbers of papers that used ICR mice as experimental animals in the social science, natural science, engineering, medicine-pharmacy, marine agricultur...

  12. Solar greenhouse assisted biogas plant in hilly region - A field study

    Energy Technology Data Exchange (ETDEWEB)

    Vinoth Kumar, K.; Kasturi Bai, R. [Department of Bio-Energy, School of Energy, Environment and Natural Resources, Madurai Kamaraj University, Madurai 625 021, Tamil Nadu (India)

    2008-10-15

    The present study was undertaken with the objective of evaluating plastic as an alternative material for biogas plant on a par with conventional brick material. The field study was carried out for one year (October, 2005-September, 2006) in a small hamlet at Nilgiris incorporating solar energy to study its influence on biogas production. During summer (April-June) the temperature reaches to the maximum of 21-25 C and the minimum of 10-12 C. During winter (October-December), the temperature available is maximum of 16-21 C and minimum of 2 C. The solar insolation in the study area ranges from 250 to 600 W/m{sup 2}. This study involves the control conventional Deenabandhu model (Indian standard model prevailing in most part of India made of masonry structure only) and the experimental plastic tank with greenhouse canopy of similar capacity. Our previous work [Vinoth Kumar, K., Kasturi Bai, R., 2005. Plastic biodigesters - a systematic study. Energy for Sustainable Development 9 (4), 40-49] on lab scale digester made from plastic material was compared over other materials and the results gave us much confidence to carry out further study on pilot scale. In continuation, a semi-continuous study was conducted for one year with the retention time of 55 days. The gas generated from the biogas plants was utilized for cooking (burner) and lighting (lamp) purposes. The yearly average slurry temperatures recorded during the study period was 26.3 and 22.4 C in experimental and control biogas plants against ambient temperature of 17.0 C. The yearly average greenhouse chamber temperature recorded was 29.1 C in the experimental biogas plant. The yearly average gas yield from the experimental and control biogas plants were 39.1 and 34.6 l kg{sup -1}day{sup -1} respectively. Gas productions in the winter season registered lower than other months. It can be concluded that the solar greenhouse assisted plastic biogas plant can be efficiently adopted with minor modifications in hilly

  13. Studies of solar magnetic fields. V. The true average field strengths near the poles

    Energy Technology Data Exchange (ETDEWEB)

    Howard, R [Hale Observatories, Pasadena, Calif. (USA)

    1977-05-01

    An estimate of the average magnetic field strength at the poles of the Sun from Mount Wilson measurements is made by comparing low latitude magnetic measurements in the same regions made near the center of the disk and near the limb. There is still some uncertainty because the orientation angle of the field lines in the meridional plane is unknown, but the most likely possibility is that the true average field strengths are about twice the measured values (0-2 G), with an absolute upper limit on the underestimation of the field strengths of about a factor 5. The measurements refer to latitudes below about 80/sup 0/.

  14. Non-Abelian gauge fields in two spatial dimensions

    International Nuclear Information System (INIS)

    Hagen, C.R.

    1987-01-01

    Generalizing an earlier work on the Abelian case the most general non-Abelian gauge theory in two spatial dimensions is derived. It is shown that local gauge invariance leads to a new term in the action which in turn requires that the gauge current operator have a part which is bilinear in the non-Abelian gauge field-strength tensor. Although a radiation (or axial) gauge quantization is possible, this approach is found not to yield the maximal set of commutation relations among the basic fields. The latter goal can be accomplished only by a rather unusual gauge choice which has not previously been studied. Quantization conditions on the coupling constant implied by invariance under large gauge transformations are also derived

  15. Field avian metapneumovirus evolution avoiding vaccine induced immunity.

    Science.gov (United States)

    Catelli, Elena; Lupini, Caterina; Cecchinato, Mattia; Ricchizzi, Enrico; Brown, Paul; Naylor, Clive J

    2010-01-22

    Live avian metapneumovirus (AMPV) vaccines have largely brought turkey rhinotracheitis (TRT) under control in Europe but unexplained outbreaks still occur. Italian AMPV longitudinal farm studies showed that subtype B AMPVs were frequently detected in turkeys some considerable period after subtype B vaccination. Sequencing showed these to be unrelated to the previously applied vaccine. Sequencing of the entire genome of a typical later isolate showed numerous SH and G protein gene differences when compared to both a 1987 Italian field isolate and the vaccine in common use. Experimental challenge of vaccinated birds with recent virus showed that protection was inferior to that seen after challenge with the earlier 1987 isolate. Field virus had changed in key antigenic regions allowing replication and leading to disease in well vaccinated birds.

  16. From free fields to AdS space: Thermal case

    International Nuclear Information System (INIS)

    Furuuchi, Kazuyuki

    2005-01-01

    We analyze the reorganization of free field theory correlators to closed string amplitudes investigated in previous papers in the case of Euclidean thermal field theory and study how the dual bulk geometry is encoded on them. The expectation value of Polyakov loop, which is an order parameter for confinement-deconfinement transition, is directly reflected on the dual bulk geometry. The dual geometry of the confined phase is found to be AdS space periodically identified in Euclidean time direction. The gluing of Schwinger parameters, which is a key step for the reorganization of field theory correlators, works in the same way as in the nonthermal case. In the deconfined phase the gluing is made possible only by taking the dual geometry correctly. The dual geometry for the deconfined phase does not have a noncontractable circle in the Euclidean time direction

  17. Recognition of emotion in hemifaces presented to the left and right visual fields.

    Science.gov (United States)

    Wedding, D; Cyrus, P

    1986-09-01

    Thirty-two right-handed subjects (16 males and 16 females) participated in a choice reaction time experiment replicating two previous studies which demonstrated the superiority of the left hemisphere in rapidly identifying facial emotion as either positive or negative. Slides of hemifaces split along the vertical axis, showing either positive (happiness, surprise) or negative (anger, disgust, or sadness) affect were presented tachistoscopically to either the left or right visual field. A 2 X 2 X 2 mixed ANOVA revealed main effects for visual field and type of affect. In contrast to earlier studies which presented full face stimuli, presentation of hemifaces produced a strong left visual field advantage and, as expected, positive faces produced faster reaction times than negative faces.

  18. Modeling and experimental study on near-field acoustic levitation by flexural mode.

    Science.gov (United States)

    Liu, Pinkuan; Li, Jin; Ding, Han; Cao, Wenwu

    2009-12-01

    Near-field acoustic levitation (NFAL) has been used in noncontact handling and transportation of small objects to avoid contamination. We have performed a theoretical analysis based on nonuniform vibrating surface to quantify the levitation force produced by the air film and also conducted experimental tests to verify our model. Modal analysis was performed using ANSYS on the flexural plate radiator to obtain its natural frequency of desired mode, which is used to design the measurement system. Then, the levitation force was calculated as a function of levitation distance based on squeeze gas film theory using measured amplitude and phase distributions on the vibrator surface. Compared with previous fluid-structural analyses using a uniform piston motion, our model based on the nonuniform radiating surface of the vibrator is more realistic and fits better with experimentally measured levitation force.

  19. Advancing the field of organizations through the study of military organizations

    DEFF Research Database (Denmark)

    Augier, Mie; Knudsen, Torbjorn; McNab, Robert M.

    2014-01-01

    This article argues that the field of organization studies may learn from closer study of decision-making and behaviors in military organizations. It describes some of the intellectual roots of organizational studies within a strategic, military context; discusses some recent characteristics...

  20. In situ electric fields causing electro-stimulation from conductor contact of charged human

    International Nuclear Information System (INIS)

    Nagai, T.; Hirata, A.

    2010-01-01

    Contact currents flow from/into a human body when touching an object such as a metal structure with a different electric potential. These currents can stimulate muscle and peripheral nerves. In this context, computational analyses of in situ electric fields caused by the contact current have been performed, while their effectiveness for transient contact currents has not well been investigated. In the present study, using an anatomically based human model, a dispersive finite-difference time-domain model was utilised to computed transient contact current and in situ electric fields from a charged human. Computed in situ electric fields were highly localised in the hand. In order to obtain an insight into the relationship between in situ electric field and electro-stimulation, cell-maximum and 5-mm averaged in situ electric fields were computed and compared with strength-duration curves. The comparison suggests that both measures could be larger than thresholds derived from the strength- duration curves with parameters used in previous studies. (authors)

  1. Effects of previous ovarian surgery for endometriosis on the outcome of assisted reproduction treatment.

    Science.gov (United States)

    Geber, Selmo; Ferreira, Daniela Parreiras; Spyer Prates, Luis Felipe Víctor; Sales, Liana; Sampaio, Marcos

    2002-01-01

    Endometriosis affects 2-50% of women at reproductive age. Surgery is an option for treatment, but there is no convincing evidence that it promotes a significant improvement in fertility. Also, the removal of ovarian endometrioma might lead to a reduction in the follicular reserve and response to stimulation. Therefore, the aim of this study was to evaluate the effect of previous ovarian surgery for endometriosis on the ovarian response in assisted reproduction treatment cycles and its pregnancy outcome. A total of 61 women, with primary infertility and previously having undergone ovarian surgery for endometriosis, who had received 74 IVF/intracytoplasmic sperm injection (ICSI) cycles, were studied (study group). A further 74 patients with primary infertility who underwent 77 IVF/ICSI cycles within#10; the same period of time, at the same clinic and without previous ovarian surgery or endometriosis were studied as a control group. Patients were matched for age and treatment performed. Patients 35 years with previous ovarian surgery needed more ampoules for ovulation induction (P = 0.017) and had fewer follicles and oocytes than women in the control group (P = 0.001). Duration of folliculogenesis was similar in both groups, as was fertilization rate. A total of 10 patients achieved pregnancy in the study group (34.5%) and 14 (48.3%) in the control group. Although a lower pregnancy rate was observed in patients who had undergone previous ovarian surgery, this difference was not statistically significant (P = 0.424). In conclusion, ovarian surgery for the treatment of endometriosis reduces the ovarian outcome in IVF/ICSI cycles in women >35 years old, and might also decrease pregnancy rates. Therefore, for infertile patients, non-surgical treatment might be a better option to avoid reduction of the ovarian response.

  2. Effects of cannabis on eyewitness memory : A field study

    NARCIS (Netherlands)

    Vredeveldt, Annelies; Charman, Steve D.; den Blanken, Aukje; Hooydonk, Maren

    2018-01-01

    Eyewitnesses to crimes are regularly under the influence of drugs, such as cannabis. Yet there is very little research on how the use of cannabis affects eyewitness memory. In the present study, we assessed the effects of cannabis on eyewitness recall and lineup identification performance in a field

  3. Short-and long-term effects of discharged OBM cuttings, with and without previous washing, tested in field and laboratory studies on the Dutch continental shelf, 1985-1990

    International Nuclear Information System (INIS)

    De Jong, A.; Zevenboom, W.; Van Het Groenewoud, H.; Daan, R.

    1991-01-01

    This paper reports on a Dutch programme that was carried out to study the distribution of discharged washed and unwashed oil-containing cuttings in the sediment and waterphase and their effects on selected test species in the Dutch part of the North Sea. The distribution of OBM cuttings in sediment around drilling locations was related to the total amount of oil discharged in the watercolumn. Increased oil contents were found over a range of 1000 to 5000 m in residual current direction. Total oil contents remained high at locations where unwashed OBM cuttings were discharged. At one location oil was found in high concentrations up to 6 years after discharge of OBM cuttings, especially due to the persistence of the oil fractions Other peaks and UCM. Washing of OBM cuttings resulted in lower amounts of oil discharged, lower concentrations in the sediment in the vicinity of the platform (up to 100 m), equal concentrations at 250 m but higher concentrations up to at more than 500 m off the platform when compared with unwashed cuttings and the respective amount of oil discharged. However, within one year, degradation of oil seems to have taken place at one of the washed sites at 5000 m. During discharge in the watercolumn, oil was taken up by Mytilus edulis from washed cuttings as well as from unwashed cuttings. Leaching of oil from the sediment into the waterphase was measurable in the field for only a limited period to time, less than a year after discharge. Several sediment-inhabiting species were tested on their response to oil contamination. Four species tested in experimental boxcosm set-ups, Echinocardium cordatum, Amphiura filiformis, Lagis koreni and Nucula turgida responded to elevated contamination levels by increased mortality

  4. Using optic flow in the far peripheral field.

    Science.gov (United States)

    McManus, Meaghan; D'Amour, Sarah; Harris, Laurence R

    2017-07-01

    Self-motion information can be used to update spatial memory of location through an estimate of a change in position. Viewing optic flow alone can create Illusory self-motion or "vection." Early studies suggested that peripheral vision is more effective than central vision in evoking vection, but controlling for retinal area and perceived distance suggests that all retinal areas may be equally effective. However, the contributions of the far periphery, beyond 90°, have been largely neglected. Using a large-field Edgeless Graphics Geometry display (EGG, Christie, Canada, field of view ±112°) and systematically blocking central (±20° to ±90°) or peripheral (viewing through tunnels ±20° to ±40°) parts of the field, we compared the effectiveness of different retinal regions at evoking forwards linear vection. Fifteen participants indicated when they had reached the position of a previously presented target after visually simulating motion down a simulated corridor. The amount of simulated travel needed to match a given target distance was modelled with a leaky spatial integrator model to estimate gains (perceived/actual distance) and a spatial decay factor. When optic flow was presented only in the far periphery (beyond 90°) gains were significantly higher than for the same motion presented full field or in only the central field, resulting in accurate performance in the range of speeds associated with normal walking. The increased effectiveness of optic flow in the peripheral field alone compared to full-field motion is discussed in terms of emerging neurophysiological studies that suggest brain areas dedicated to processing information from the far peripheral field.

  5. Ionospheric quasi-static electric field anomalies during seismic activity in August–September 1981

    Directory of Open Access Journals (Sweden)

    M. Gousheva

    2009-01-01

    Full Text Available The paper proposes new results, analyses and information for the plate tectonic situation in the processing of INTERCOSMOS-BULGARIA-1300 satellite data about anomalies of the quasi-static electric field in the upper ionosphere over activated earthquake source regions at different latitudes. The earthquake catalogue is made on the basis of information from the United State Geological Survey (USGS website. The disturbances in ionospheric quasi-static electric fields are recorded by IESP-1 instrument aboard the INTERCOSMOS-BULGARIA-1300 satellite and they are compared with significant seismic events from the period 14 August–20 September 1981 in magnetically very quiet, quiet and medium quiet days. The main tectonic characteristics of the seismically activated territories are also taken in account. The main goal of the above research work is to enlarge the research of possible connections between anomalous vertical electric field penetrations into the ionosphere and the earthquake manifestations, also to propose tectonic arguments for the observed phenomena. The studies are represented in four main blocks: (i previous studies of similar problems, (ii selection of satellite, seismic and plate tectonic data, (iii data processing with new specialized software and observations of the quasi-static electric field and (iiii summary, comparison of new with previous results in our studies and conclusion. We establish the high informativity of the vertical component Ez of the quasi-static electric field in the upper ionosphere according observations by INTERCOSMOS-BULGARIA-1300 that are placed above considerably activated earthquake sources. This component shows an increase of about 2–10 mV/m above sources, situated on mobile structures of the plates. The paper discusses the observed effects. It is represented also a statistical study of ionospheric effects 5–15 days before and 5–15 days after the earthquakes with magnitude M 4.8–7.9.

  6. Atom probe field ion microscopy and related topics: A bibliography 1992

    Energy Technology Data Exchange (ETDEWEB)

    Russell, K.F.; Godfrey, R.D.; Miller, M.K.

    1993-12-01

    This bibliography contains citations of books, conference proceedings, journals, and patents published in 1992 on the following types of microscopy: atom probe field ion microscopy (108 items); field emission microscopy (101 items); and field ion microscopy (48 items). An addendum of 34 items missed in previous bibliographies is included.

  7. The long-term consequences of previous hyperthyroidism

    DEFF Research Database (Denmark)

    Hjelm Brandt Kristensen, Frans

    2015-01-01

    Thyroid hormones affect every cell in the human body, and the cardiovascular changes associated with increased levels of thyroid hormones are especially well described. As an example, short-term hyperthyroidism has positive chronotropic and inotropic effects on the heart, leading to a hyperdynamic...... with CVD, LD and DM both before and after the diagnosis of hyperthyroidism. Although the design used does not allow a stringent distinction between cause and effect, the findings indicate a possible direct association between hyperthyroidism and these morbidities, or vice versa....... vascular state. While it is biologically plausible that these changes may induce long-term consequences, the insight into morbidity as well as mortality in patients with previous hyperthyroidism is limited. The reasons for this are a combination of inadequately powered studies, varying definitions...

  8. Frequency Dependent Non- Thermal Effects of Oscillating Electric Fields in the Microwave Region on the Properties of a Solvated Lysozyme System: A Molecular Dynamics Study.

    Directory of Open Access Journals (Sweden)

    Stelios Floros

    Full Text Available The use of microwaves in every day's applications raises issues regarding the non thermal biological effects of microwaves. In this work we employ molecular dynamics simulations to advance further the dielectric studies of protein solutions in the case of lysozyme, taking into consideration possible frequency dependent changes in the structural and dynamic properties of the system upon application of electric field in the microwave region. The obtained dielectric spectra are identical with those derived in our previous work using the Fröhlich-Kirkwood approach in the framework of the linear response theory. Noticeable structural changes in the protein have been observed only at frequencies near its absorption maximum. Concerning Cα position fluctuations, different frequencies affected different regions of the protein sequence. Furthermore, the influence of the field on the kinetics of protein-water as well as on the water-water hydrogen bonds in the first hydration shell has been studied; an extension of the Luzar-Chandler kinetic model was deemed necessary for a better fit of the applied field results and for the estimation of more accurate hydrogen bond lifetime values.

  9. Integrated Study of Lithofacies Identification—A Case Study in X Field, Sabah, Malaysia

    Directory of Open Access Journals (Sweden)

    Jia Qi Ngui

    2018-02-01

    Full Text Available Understanding subsurface geology is essential for oil and gas exploration. Seismic facies interpretation is very useful in investigating this concept. The interpretation of the depositional setting of the X Field is achieved by integrating the seismic facies characteristics on 3D seismic data and well log data. Both the seismic and well log data are widely used in hydrocarbon exploration to map the subsurface, as they complement each other. Well logs yield the vertical resolution of the subsurface geology at the drilled well, whereas seismic data reveal the lateral continuity. The objective of this paper is to demonstrate the integration of 3D seismic data and well log data for lithofacies identification. Interpretation and analysis of lithofacies is carried out through the integration of the characteristics of seismic reflections with well information (logs. Horizons are interpreted based on the variation in seismic reflections on the seismic section, which is caused by the change in geology within seismic sequences. Well logs give detailed information at the points where the wells were drilled. Interpolating between these points and extrapolating away from the points into undrilled areas can be helpful in providing a better geological knowledge of an area. The result of this integrated study depicts the lithofacies in the area. This integrated study will provide a better insight with higher degree of reliability to the facies distribution and depositional setting of the X Field. The geological and geophysical aspects of the field will be documented.

  10. Study of marine magnetic field

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattacharya, G.C.

    magnetized in the direction of the Earth’s magnetic field at that time. As seafloor spreading pulls the new oceanic crust apart, stripes of approximately the same size gets carried away from the ridge on each side. The basaltic oceanic crust formed...

  11. Association between previous splenectomy and gastric dilatation-volvulus in dogs: 453 cases (2004-2009).

    Science.gov (United States)

    Sartor, Angela J; Bentley, Adrienne M; Brown, Dorothy C

    2013-05-15

    To evaluate the association between previous splenectomy and gastric dilatation-volvulus (GDV) in dogs. Multi-institutional retrospective case-control study. Animals-151 dogs treated surgically for GDV and 302 control dogs with no history of GDV. Computerized records of dogs evaluated via exploratory laparotomy or abdominal ultrasonography were searched, and dogs with GDV and dogs without GDV (control dogs) were identified. Two control dogs were matched with respect to age, body weight, sex, neuter status, and breed to each dog with GDV. Data were collected on the presence or absence of the spleen for both dogs with GDV and control dogs. Conditional logistic regression analysis was used to investigate the association of previous splenectomy with GDV. 6 (4%) dogs in the GDV group and 3 (1%) dogs in the control group had a history of previous splenectomy. The odds of GDV in dogs with a history of previous splenectomy in this population of dogs were 5.3 times those of dogs without a history of previous splenectomy (95% confidence interval, 1.1 to 26.8). For the patients in the present study, there was an increased odds of GDV in dogs with a history of splenectomy. Prophylactic gastropexy may be considered in dogs undergoing a splenectomy, particularly if other risk factors for GDV are present.

  12. Astronaut Neil Armstrong studies rock samples during geological field trip

    Science.gov (United States)

    1969-01-01

    Astronaut Neil Armstrong, commander of the Apollo 11 lunar landing mission, studies rock samples during a geological field trip to the Quitman Mountains area near the Fort Quitman ruins in far west Texas.

  13. Fuzzy logic based ELF magnetic field estimation in substations

    International Nuclear Information System (INIS)

    Kosalay, I.

    2008-01-01

    This paper examines estimation of the extremely low frequency magnetic fields (MF) in the power substation. First, the results of the previous relevant research studies and the MF measurements in a sample power substation are presented. Then, a fuzzy logic model based on the geometric definitions in order to estimate the MF distribution is explained. Visual software, which has a three-dimensional screening unit, based on the fuzzy logic technique, has been developed. (authors)

  14. Effects of a static electric field on two-color photoassociation between different atoms

    International Nuclear Information System (INIS)

    Chakraborty, Debashree; Deb, Bimalendu

    2014-01-01

    We study non-perturbative effects of a static electric field on two-color photoassociation of different atoms. A static electric field induces anisotropy in scattering between two different atoms and hybridizes field-free rotational states of heteronuclear dimers or polar molecules. In a previous paper [D. Chakraborty et al., J. Phys. B 44, 095201 (2011)], the effects of a static electric field on one-color photoassociation between different atoms has been described through field-modified ground-state scattering states, neglecting electric field effects on heteronuclear diatomic bound states. To study the effects of a static electric field on heteronuclear bound states, and the resulting influence on Raman-type two-color photoassociation between different atoms in the presence of a static electric field, we develop a non-perturbative numerical method to calculate static electric field-dressed heteronuclear bound states. We show that the static electric field induced scattering anisotropy as well as hybridization of rotational states strongly influence two-color photoassociation spectra, leading to significant enhancement in PA rate and large shift. In particular, for static electric field strengths of a few hundred kV/cm, two-color PA rate involving high-lying bound states in electronic ground-state increases by several orders of magnitude even in the weak photoassociative coupling regime

  15. Propagators for a quantized scalar field in a static closed universe

    International Nuclear Information System (INIS)

    Nariai, Hidekazu; Azuma, Takahiro.

    1978-07-01

    In a previous paper, a massive scalar field in an expanding closed universe was canonically quantized by taking full account of its coupling-type with the background universe and of the latter's topological (spherical or elliptic) nature. General formulae (including the parts of vacuum fluctuation which should after all be removed by a suitable regularization) for the energy density and pressure of the quantized medium were derived. Various propagators for the quantized scalar field were also dealt with, because the Feynman propagator in particular became important as soon as the pair-creation of those particles was called for. However, there will be an intimate relation between the former hydrodynamic quantities and the pair-creation of their constituents. Accordingly, this problem is studied in detail by adopting a static closed universe (for simplicity in the reduction of various expressions derived in the previous paper) and examining the behavior of various bi-scalar propagators in the universe. (author)

  16. [Prevalence of previously diagnosed diabetes mellitus in Mexico.

    Science.gov (United States)

    Rojas-Martínez, Rosalba; Basto-Abreu, Ana; Aguilar-Salinas, Carlos A; Zárate-Rojas, Emiliano; Villalpando, Salvador; Barrientos-Gutiérrez, Tonatiuh

    2018-01-01

    To compare the prevalence of previously diagnosed diabetes in 2016 with previous national surveys and to describe treatment and its complications. Mexico's national surveys Ensa 2000, Ensanut 2006, 2012 and 2016 were used. For 2016, logistic regression models and measures of central tendency and dispersion were obtained. The prevalence of previously diagnosed diabetes in 2016 was 9.4%. The increase of 2.2% relative to 2012 was not significant and only observed in patients older than 60 years. While preventive measures have increased, the access to medical treatment and lifestyle has not changed. The treatment has been modified, with an increase in insulin and decrease in hypoglycaemic agents. Population aging, lack of screening actions and the increase in diabetes complications will lead to an increase on the burden of disease. Policy measures targeting primary and secondary prevention of diabetes are crucial.

  17. Preliminary study : Extremely low frequency electromagnetic field (ELF EMF) effects on the growth of plant

    International Nuclear Information System (INIS)

    Roha Tukimin; Wan Norsuhaila Wan Aziz; Rozaimah Abd Rahim; Wan Saffiey Wan Abdulah

    2010-01-01

    A research has been done to study the effects of magnetic fields on the growth of plants.Two samples of maize seedlings and green beans have been studied. Helmholtz coil systems were used as magnetic field source at frequency 50 Hz with 440 mGauss field strength. Sample characteristics such height, leaf, colour and length of roots were observed. The results show that the magnetic field influenced the growth of the sample. The sample that were exposed to the magnetic field show faster growth compared to the controlled sample. (author)

  18. Environmental coefficients of the free-field sensitivity of measurement microphones

    DEFF Research Database (Denmark)

    Barrera Figueroa, Salvador; Cutanda Henriquez, Vicente; Torras-Rosell, Antoni

    2017-01-01

    The sensitivity of measurement microphones, both pressure and free field, is affected by changes in the environmental conditions, mainly temperature and static pressure. Static pressure and temperature coefficients for the pressure sensitivity have been the object of previous studies focused...... on Laboratory Standard microphones and few working standard microphones. The literature describes frequency dependent values for these coefficients which are used for calibration purposes. However, there is no description of the environmental coefficients of the free-field sensitivity though there have been...... some implementations that attempt to take care of the differences between the coefficients for the two types of sensitivities. Measuring the coefficients in a free field poses some challeng; it is not so easy to change neither the static pressure nor the temperature inside anechoic room within...

  19. Realistic edge field model code REFC for designing and study of isochronous cyclotron

    International Nuclear Information System (INIS)

    Ismail, M.

    1989-01-01

    The focussing properties and the requirements for isochronism in cyclotron magnet configuration are well-known in hard edge field model. The fact that they quite often change considerably in realistic field can be attributed mainly to the influence of the edge field. A solution to this problem requires a field model which allows a simple construction of equilibrium orbit and yield simple formulae. This can be achieved by using a fitted realistic edge field (Hudson et al 1975) in the region of the pole edge and such a field model is therefore called a realistic edge field model. A code REFC based on realistic edge field model has been developed to design the cyclotron sectors and the code FIELDER has been used to study the beam properties. In this report REFC code has been described along with some relevant explaination of the FIELDER code. (author). 11 refs., 6 figs

  20. Previous Employment and Job Satisfaction Conditions: The Case of Regional Administration

    Science.gov (United States)

    Amalia, Myronaki; Nikolaos, Antonakas

    2009-08-01

    In the present work we study the different dimensions of satisfaction and the way of constitution of satisfaction of an important sample of the employees in the Regional administration of Crete and in their connection with the variable of the previous employment. We found statistically important differences for the components of satisfaction from the life, collaboration in and outside from the department, in the social satisfaction and the variable of the years in the service (labour group with satisfaction than the other previous employment groups. In the other hand the group with many years in the service presents bigger satisfaction than the other groups. Finally, is important to note that the sample present some interesting characteristics.