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Sample records for osce composite npe

  1. Modeling the NPE

    Energy Technology Data Exchange (ETDEWEB)

    Bos, R. [Los Alamos National Lab., NM (United States)

    1994-12-31

    Calculations using the Sandia National Laboratory Eulerian hydrodynamic code CTH were performed to model the NPE. The calculations were primarily intended to confirm the adequacy of the tuff equation of state for near field calculations. Results compared with experimental data indicate good agreement in the range that the eos is considered to be valid (>1GPa). Results for the intermediate field are also given and show where the near field eos starts to be suspect.

  2. Preliminary results on the NPE experiment

    Energy Technology Data Exchange (ETDEWEB)

    Cansi, Y.; Crusem, R.; Masso, J.P. [CEA, Chatel (France)] [and others

    1994-12-31

    Answering to an invitation of the DOE, the Laboratoire de Detection et de Geophysique du Commissariat a I`Energie Atomique (CEA/LDG) participated to the seismic measurements associated with the NPE Experiment organized by the DOE at the Nevada Test Site. Our main motivations were: to evaluate and compare the capabilities of detection and location of the two types of the so-called alpha stations which composed the Experimental International Seismic System (i.e.: the composite stations and the miniarrays) and this in a regional environnement, to calibrate these stations with a chemical blast of known energy within a given propagation structure.

  3. Hydroacoustic observations of the NPE

    Energy Technology Data Exchange (ETDEWEB)

    Harris, D.; Hauk, T.; Breitfeller, E. [Lawrence Livermore National Lab., CA (United States)] [and others

    1994-12-31

    The NPE was observed by three hydrophone arrays located off of the coast of California: (1) a special sonobuoy pattern deployed for the Lawrence Livermore National Laboratory by COMPATWINGSSPAC, U.S. Navy, (2) the SwellEx vertical line array deployed by the Marine Physical Laboratory, Scripps Institute of Oceanography, and (3) an array of the U.S. Navy SOSUS system. The P phase from the event was just visible in the sonobuoy data, very clear on the vertical line array (after beamforming), and moderately well recorded on the SOSUS array. Calibration of the SwellEx array hydrophones and electronics allows us to estimate the pressure level of the NPE P phase at 75-80 dB re 1 uPascal**2/Hz between 2 and 9 Hz. We use observations of the HUNTERS TROPHY nuclear test to demonstrate several beamforming methods that use vertical line arrays to suppress the predominantly horizontally propagating ambient acoustic noise. Such arrays could be used to supplement seismic systems for monitoring inaccessible continental regions from adjacent oceans.

  4. Near-source surface seismic measurements for the NPE, NPE Calibration, Hunter`s Trophy, and Mineral Quarry

    Energy Technology Data Exchange (ETDEWEB)

    Reinke, R.E.; Leverette, J.A. [Field Command Defense Nuclear Agency, Kirtland AFB, NM (United States); Stump, B.W. [Los Alamos National Laboratory, NM (United States)] [and others

    1994-12-31

    An extensive seismic network was deployed on the surface of Rainier Mesa for both the Non-Proliferation Experiment (NPE) Calibration shot as well as the full scale NPE event. This network was very similar to previous deployments for the nuclear events MISTY ECHO, MINERAL QUARRY, and HUNTERS TROPHY. For the full scale NPE event three-component accelerometers and seismometers were fielded at 32 sites across the mesa. A slightly smaller network with 28 stations was in operation for the 300 pound NPE calibration event. The mesa top array included both accelerometers and seismometers. The accelerometers were used to obtain data from the main NPE event while the seismometers with their higher sensitivity were used to record the 300 pound cal shot and several hundred after events from the NPE. Large spatial variations in ground motion are evident in both the full mesa data set as well as a small (80 m on a side) aperture, 9-element triangular array. This paper summarizes the data and discusses wave propagation effects. A companion paper presents a comparative source analysis.

  5. Is OSCE successful in pediatrics?

    Directory of Open Access Journals (Sweden)

    M Imani

    2009-02-01

    Full Text Available Background: The Faculty of Medical Sciences, University of Zahedan implemented the Objective Structured Clinical Examination (OSCE in the final Examination during the 2003–2004 academic year. Simultaneously, the pediatric department initiated faculty and student training, and instituted the OSCE as an assessment instrument during the pediatric clerkship in year 5. The study set out to explore student acceptance of the OSCE as part of an evaluation of the Pediatric clerkship.Purpose: This study implemented to evaluate a new method of assessment in medical education in pediatrics.Methods: A self-administered questionnaire was completed by successive groups of students immediately after the OSCE at the end of each clerkship rotation. Main outcome measures were student perception of examination attributes, which included the quality of instructions and organization, the quality of performance, authenticity and transparency of the process, and usefulness of the OSCE as an assessment instrument compared to other methods.Results: There was overwhelming acceptance of the OSCE in Pediatric with respect to the comprehensiveness (90%, transparency (87%, fairness (57% and authenticity of the required tasks (58–78%. However, students felt that it was a strong anxiety-producing experience. And concerns were expressed regarding the ambiguity of some questions and inadequacy of time for expected tasks.Conclusion: Student feedback was invaluable in influencing faculty teaching, curriculum direction and appreciation of student opinion. Further psychometric evaluation will strengthen the development of the OSCE.Key words: OSCE, COMPETENCE ASSESSMENT

  6. National data centre preparedness exercise 2015 (NPE2015): MY-NDC progress result and experience

    Science.gov (United States)

    Rashid, Faisal Izwan Abdul; Zolkaffly, Muhammed Zulfakar

    2017-01-01

    Malaysia has established the National Data Centre (MY-NDC) in December 2005. MY-NDC is tasked to perform the Comprehensive Nuclear-Test-Ban-Treaty (CTBT) data management as well as providing relevant information for Treaty related events to the Malaysian Nuclear Agency (Nuclear Malaysia) as the CTBT National Authority. In the late 2015, MY-NDC has participated in the National Data Centre Preparedness Exercise 2015 (NPE 2015) which aims to access the level of readiness at MY-NDC. This paper aims at presenting the progress result of NPE 2015 as well as highlighting MY-NDC experience in NPE 2015 compared to previous participation in NPE 2013. MY-NDC has utilised available resources for NPE 2015. In NPE 2015, MY-NDC has performed five type of analyses compared with only two analyses in NPE 2013. Participation in the NPE 2015 has enabled MY-NDC to assess its capability and identify rooms for improvement.

  7. NPE - close-in stress and motion measurements

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.W. [Sandia National Labs., Albuquerque, NM (United States)

    1994-12-31

    On the Non-Proliferation Experiment we measured stresses and accelerations in the nonlinear regime. Measurements were made in the host rock and in the grout stemming of the access drift. The thrust of the measurements was to provide data for a comparison with waveforms from nuclear events and with calculations of the process. Measured stress waveforms show greater amplitudes than yield-scaled waveforms from nearby nuclear events. Specifically, the five stress peaks suggest an equivalent nuclear yield of more than two kilotons. Material velocity data from NPE also show amplitudes greater than nuclear data. The risetimes of the NPE data are slower than risetimes of scaled nuclear data. The ratio of risetimes is about two; this difference may prove useful in discriminating between nuclear and chemical explosions. Non-radical accelerations show some departure from symmetric wave propagation. Tuff strengths-inferred from differences between radial and hoop stresses-show values that are about twice laboratory determined values.

  8. The Psychiatry OSCE: a 20-year retrospective.

    Science.gov (United States)

    Hodges, Brian D; Hollenberg, Elisa; McNaughton, Nancy; Hanson, Mark D; Regehr, Glenn

    2014-02-01

    Twenty years ago researchers at the University of Toronto launched the Psychiatry Skills Assessment Project (PSAP), a research program exploring Objective Structured Clinical Examinations (OSCEs) in psychiatry. Between 1994 and 2005 PSAP produced publications on the feasibility, reliability, validity, ethics, and practical concerns of OSCEs in psychiatry. The current review has two parts: a review of the state of the art of OSCEs in psychiatry 20 years after they were introduced and documentation of the impact of the PSAP research program. A literature search identified all publications on OSCEs and psychiatry. Articles were coded thematically, and locations of agreement and controversies were identified. Bibliometric analysis identified citations of PSAP research papers, which were analyzed thematically. As of May 2013, there were 250 publications related to OSCEs in psychiatry (not including 10 PSAP papers), published in 29 different countries and ten languages. Prominent topics were the validity and acceptability of OSCEs and SPs, systems issues in adopting OSCEs in psychiatry, and the effects on learning. Eighty-eight percent of all publications cited PSAP work (300 citations). Citations were employed for four purposes: as evidence/justification (54 %); to frame replication research (14 %); to support adaptation of OSCEs in other countries and professions (15 %); and for debate (18 %). Over the past 20 years, use of OSCEs has grown steadily in psychiatry, and several national certification organizations have adopted OSCEs. PSAP work, introduced two decades ago, continues to provide a scholarly foundation for psychometric, practical, and ethical issues of interest to this field.

  9. Spontaneous potential and telluric measurements on Rainier Mesa relaed to the NPE

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, J.J. [Lawrence Livermore National Lab., CA (United States)

    1994-12-31

    We made measurements of spontaneous potential (SP) on Rainier Mesa to see if changes in subsurface electrical properties of rock related to the Non-Proliferation Experiment (NPE) explosion can be detected at the surface. A north-south line, repeated 3 times and running within 50 m of surface ground zero (SGZ) of Hunter`s Trophy and within 20 m of SGZ of the NPE, was measured before and after the NPE. An east-west line, with one end within 20 m of SGZ of the NPE was also run before and after the NPE. High values of surface potential along the north-south line in the vicinity of the NPE apparently moved northward after the detonation. A similar change was not noted on the east-west line. A telluric line (0.025-0.1 Hz and 8.0 Hz) was also run prior to the NPE along the same north-south line as the SP measurement, but farther to the west of SGZ for Hunter`s Trophy. There is a prominent high in the 8 Hz data in the northern part that may be related to a former nuclear test, but it could also be related to local geology. Results from these geophysical methods, while showing some promise for use in an on-site monitoring regime, also emphasize the need for repeatable background reference data.

  10. Pabriks denied in OSCE challenge / Lelde Benke

    Index Scriptorium Estoniae

    Benke, Lelde

    2010-01-01

    OSCE parlamentaarse assamblee peasekretäriks sai uuesti Spencer Oliver, keda toetas 95% hääletanutest. Läti endine välisminister Artis Pabriks, kes tahtis muuta OSCE PA peasekretäri valimisprotsessi ja hääletussüsteemi, kaotas

  11. Temporary tattoos: a novel OSCE assessment tool.

    Science.gov (United States)

    Gormley, Gerry; Menary, Allison; Layard, Brooke; Hart, Nigel; McCourt, Collette

    2013-08-01

    There are many issues regarding the use of real patients in objective structured clinical examinations (OSCEs). In dermatology OSCE stations, standardised patients (SPs) with clinical photographs are often used. Temporary transfer tattoos can potentially simulate skin lesions when applied to an SP. This study aims to appraise the use of temporary malignant melanoma tattoos within an OSCE framework. Within an 11-station OSCE, a temporary malignant melanoma tattoo was developed and applied to SPs in a 'skin lesion' OSCE station. A questionnaire captured the opinions of the candidate, SP and examiners, and the degree of perceived realism of each station was determined. Standard post hoc OSCE analysis determined the psychometric reliability of the stations. The response rates were 95.9 per cent of candidates and 100 per cent of the examiners and SPs. The 'skin lesion' station achieved the highest realism score compared with other stations: 89.0 per cent of candidates felt that the skin lesion appeared realistic; only 28 per cent of candidates had ever seen a melanoma before in training. The psychometric performance of the melanoma station was comparable with, and in many instances better than, other OSCE stations. Transfer tattoo technology facilitates a realistic dermatology OSCE station encounter. Temporary tattoos, alongside trained SPs, provide an authentic, standardised and reliable experience, allowing the assessment of integrated dermatology clinical skills. © 2013 John Wiley & Sons Ltd.

  12. National Data Center Preparedness Exercise 2015 (NPE 2015): MY-NDC Preliminary Analysis Result

    International Nuclear Information System (INIS)

    Faisal Izwan Abdul Rashid; Muhammed Zulfakar Zolkaffly

    2016-01-01

    Malaysia has established the CTBT National Data Centre (MY-NDC) in December 2005. MY-NDC is tasked to perform Comprehensive Nuclear-Test-Ban-Treaty (CTBT) data management as well as provide information for Treaty related events to Nuclear Malaysia as CTBT National Authority. In 2015, MY-NDC has participated in the National Data Centre Preparedness Exercise 2015 (NPE 2015). This paper aims at presenting MY-NDC preliminary analysis result of NPE 2015. In NPE 2015, MY-NDC has performed five different analyses, namely, radionuclide, atmospheric transport modelling (ATM), data fusion, seismic analysis and site forensics. The preliminary findings show the hypothetical scenario in NPE 2015 most probably is an uncontained event resulted high release of radionuclide to the air. (author)

  13. Low-altitude overhead imagery acquisition pre- and post-NPE

    Energy Technology Data Exchange (ETDEWEB)

    Pickles, W.L. [Lawerence Livermore National Lab., CA (United States); Shines, J.E.; Hawley, D.L. [and others

    1994-12-31

    We have successfully acquired all the planned overhead imagery (OHI) of the Non-Proliferation Experiment (NPE). The data set is very large and complete. Image mosaics of the area around the NPE Ground Zero (GZ) were taken at 37 12.6948N by 116 12 35.496W on top of Rainier Mesa in Areas 12 at NTS. The data were taken from a total of eight overflights on six different days. Preliminary analysis of the thermal infrared, 8-12.5-micron scanner band, taken before and after the NPE, shows some low-emission effects in virgin soil after the NPE. These effects could be due to the acceleration of the surface caused by NPE. Preliminary analysis of the visible high-resolution color RC-30 photography shows the senescence of oak leaves in an areas of 2 km around GZ. Several other groups also independently observed this phenomenon when they returned to the mesa on Friday morning, 48 hours after the NPE. Detailed study of the photography and the scanner data will be necessary to map the actual aerial extent of the senescence. If the effect is proven to be limited to the area around GZ, then we will have supporting evidence that we have actually observed shock-induced premature senescence of oak leaves. Such overhead imagery could be used to help reduce the search area during an on-site inspection as part of the Comprehensive Test Ban Treaty verification activities.

  14. Back to the future: An online OSCE Management Information System for nursing OSCEs.

    Science.gov (United States)

    Meskell, Pauline; Burke, Eimear; Kropmans, Thomas J B; Byrne, Evelyn; Setyonugroho, Winny; Kennedy, Kieran M

    2015-11-01

    The Objective Structured Clinical Examination (OSCE) is an established tool in the repertoire of clinical assessment methods in nurse education. The use of OSCEs facilitates the assessment of psychomotor skills as well as knowledge and attitudes. Identified benefits of OSCE assessment include development of students' confidence in their clinical skills and preparation for clinical practice. However, a number of challenges exist with the traditional paper methodology, including documentation errors and inadequate student feedback. To explore electronic OSCE delivery and evaluate the benefits of using an electronic OSCE management system. To explore assessors' perceptions of and attitudes to the computer based package. This study was conducted using electronic software in the management of a four station OSCE assessment with a cohort of first year undergraduate nursing students delivered over two consecutive years (n=203) in one higher education institution in Ireland. A quantitative descriptive survey methodology was used to obtain the views of the assessors on the process and outcome of using the software. OSCE documentation was converted to electronic format. Assessors were trained in the use of the OSCE management software package and laptops were procured to facilitate electronic management of the OSCE assessment. Following the OSCE assessment, assessors were invited to evaluate the experience. Electronic software facilitated the storage and analysis of overall group and individual results thereby offering considerable time savings. Submission of electronic forms was allowed only when fully completed thus removing the potential for missing data. The feedback facility allowed the student to receive timely evaluation on their performance and to benchmark their performance against the class. Assessors' satisfaction with the software was high. Analysis of assessment results can highlight issues around internal consistency being moderate and examiners variability

  15. Taking OSCE examiner training on the road: reaching the masses.

    Science.gov (United States)

    Reid, Katharine; Smallwood, David; Collins, Margo; Sutherland, Ruth; Dodds, Agnes

    To ensure the rigour of objective structured clinical examinations (OSCEs) in assessing medical students, medical school educators must educate examiners with a view to standardising examiner assessment behaviour. Delivering OSCE examiner training is a necessary yet challenging part of the OSCE process. A novel approach to implementing training for current and potential OSCE examiners was trialled by delivering large-group education sessions at major teaching hospitals. The 'OSCE Roadshow' comprised a short training session delivered in the context of teaching hospital 'Grand Rounds' to current and potential OSCE examiners. The training was developed to educate clinicians about OSCE processes, clarify the examiners' role and required behaviours, and to review marking guides and mark allocation in an effort to standardise OSCE processes and encourage consistency in examiner marking behaviour. A short exercise allowed participants to practise marking a mock OSCE to investigate examiner marking behaviour after the training. OSCE Roadshows at four metropolitan and one rural teaching hospital were well received and well attended by 171 clinicians across six sessions. Unexpectedly, medical students also attended in large numbers ( n= 220). After training, participants' average scores for the mock OSCE clustered closely around the ideal score of 28 (out of 40), and the average scores did not differ according to the levels of clinical experience. The OSCE Roadshow demonstrated the potential of brief familiarisation training in reaching large numbers of current and potential OSCE examiners in a time and cost-effective manner to promote standardisation of OSCE processes.

  16. Bearing Condition Recognition and Degradation Assessment under Varying Running Conditions Using NPE and SOM

    Directory of Open Access Journals (Sweden)

    Shaohui Zhang

    2014-01-01

    Full Text Available Manifold learning methods have been widely used in machine condition monitoring and fault diagnosis. However, the results reported in these studies focus on the machine faults under stable loading and rotational speeds, which cannot interpret the practical machine running. Rotating machine is always running under variable speeds and loading, which makes the vibration signal more complicated. To address such concern, the NPE (neighborhood preserving embedding is applied for bearing fault classification. Compared with other algorithms (PCA, LPP, LDA, and ISOP, the NPE performs well in feature extraction. Since the traditional time domain signal denoising is time consuming and memory consuming, we denoise the signal features directly in feature space. Furthermore, NPE and SOM (self-organizing map are combined to assess the bearing degradation performance. Simulation and experiment results validate the effectiveness of the proposed method.

  17. Electronic acquisition of OSCE performance using tablets

    Directory of Open Access Journals (Sweden)

    Hochlehnert, Achim

    2015-10-01

    Full Text Available Background: Objective Structured Clinical Examinations (OSCEs often involve a considerable amount of resources in terms of materials and organization since the scores are often recorded on paper. Computer-assisted administration is an alternative with which the need for material resources can be reduced. In particular, the use of tablets seems sensible because these are easy to transport and flexible to use.Aim: User acceptance concerning the use of tablets during OSCEs has not yet been extensively investigated. The aim of this study was to evaluate tablet-based OSCEs from the perspective of the user (examiner and the student examinee.Method: For two OSCEs in Internal Medicine at the University of Heidelberg, user acceptance was analyzed regarding tablet-based administration (satisfaction with functionality and the subjective amount of effort as perceived by the examiners. Standardized questionnaires and semi-standardized interviews were conducted (complete survey of all participating examiners. In addition, for one OSCE, the subjective evaluation of this mode of assessment was gathered from a random sample of participating students in semi-standardized interviews.Results: Overall, the examiners were very satisfied with using tablets during the assessment. The subjective amount of effort to use the tablet was found on average to be “hardly difficult”. The examiners identified the advantages of this mode of administration as being in particular the ease of use and low rate of error. During the interviews of the examinees, acceptance for the use of tablets during the assessment was also detected.Discussion: Overall, it was found that the use of tablets during OSCEs was well accepted by both examiners and examinees. We expect that this mode of assessment also offers advantages regarding assessment documentation, use of resources, and rate of error in comparison with paper-based assessments; all of these aspects should be followed up on in

  18. Task Demands in OSCEs Influence Learning Strategies.

    Science.gov (United States)

    Lafleur, Alexandre; Laflamme, Jonathan; Leppink, Jimmie; Côté, Luc

    2017-01-01

    Models on pre-assessment learning effects confirmed that task demands stand out among the factors assessors can modify in an assessment to influence learning. However, little is known about which tasks in objective structured clinical examinations (OSCEs) improve students' cognitive and metacognitive processes. Research is needed to support OSCE designs that benefit students' metacognitive strategies when they are studying, reinforcing a hypothesis-driven approach. With that intent, hypothesis-driven physical examination (HDPE) assessments ask students to elicit and interpret findings of the physical exam to reach a diagnosis ("Examine this patient with a painful shoulder to reach a diagnosis"). When studying for HDPE, students will dedicate more time to hypothesis-driven discussions and practice than when studying for a part-task OSCE ("Perform the shoulder exam"). It is expected that the whole-task nature of HDPE will lead to a hypothesis-oriented use of the learning resources, a frequent use of adjustment strategies, and persistence with learning. In a mixed-methods study, 40 medical students were randomly paired and filmed while studying together for two hypothetical OSCE stations. Each 25-min study period began with video cues asking to study for either a part-task OSCE or an HDPE. In a crossover design, sequences were randomized for OSCEs and contents (shoulder or spine). Time-on-task for discussions or practice were categorized as "hypothesis-driven" or "sequence of signs and maneuvers." Content analysis of focus group interviews summarized students' perception of learning resources, adjustment strategies, and persistence with learning. When studying for HDPE, students allocate significantly more time for hypothesis-driven discussions and practice. Students use resources contrasting diagnoses and report persistence with learning. When studying for part-task OSCEs, time-on-task is reversed, spent on rehearsing a sequence of signs and maneuvers. OSCEs with

  19. Does student performance on preclinical OSCEs relate to clerkship grades?

    Directory of Open Access Journals (Sweden)

    Margot Chima

    2016-06-01

    Full Text Available Background: Objective structured clinical examinations (OSCEs have been used to assess the clinical competence and interpersonal skills of healthcare professional students for decades. However, the relationship between preclinical (second year or M2 OSCE grades and clerkship performance had never been evaluated, until it was explored to provide information to educators at the University of Nebraska Medical Center (UNMC. In addition, the relationship between M2 OSCE communication scores (which is a portion of the total score and third-year (M3 Internal Medicine (IM clerkship OSCE scores was also explored. Lastly, conflicting evidence exists about the relationship between the amount of previous clinical experience and OSCE performance. Therefore, the relationship between M3 IM clerkship OSCE scores and the timing of the clerkship in the academic year was explored. Methods: Data from UNMC M2 OSCEs and M3 IM clerkship OSCEs were obtained for graduates of the 2013 and 2014 classes. Specifically, the following data points were collected: M2 fall OSCE total, M2 fall OSCE communication; M2 spring OSCE total, M2 spring OSCE communication; and M3 IM clerkship OSCE total percentages. Data were organized by class, M3 IM clerkship OSCE performance, and timing of the clerkship. Microsoft Excel and SPSS were used for data organization and analysis. Results: Of the 245 records, 229 (93.5% had data points for all metrics of interest. Significant differences between the classes of 2013 and 2014 existed for average M2 spring total, M2 spring communication, and M3 IM clerkship OSCEs. Retrospectively, there were no differences in M2 OSCE performances based on how students scored on the M3 IM clerkship OSCE. M3 IM clerkship OSCE performance improved for those students who completed the clerkship last in the academic year. Conclusions: There were inconsistencies in OSCE performances between the classes of 2013 and 2014, but more information is needed to determine if

  20. Does student performance on preclinical OSCEs relate to clerkship grades?

    Science.gov (United States)

    Chima, Margot; Dallaghan, Gary Beck

    2016-01-01

    Objective structured clinical examinations (OSCEs) have been used to assess the clinical competence and interpersonal skills of healthcare professional students for decades. However, the relationship between preclinical (second year or M2) OSCE grades and clerkship performance had never been evaluated, until it was explored to provide information to educators at the University of Nebraska Medical Center (UNMC). In addition, the relationship between M2 OSCE communication scores (which is a portion of the total score) and third-year (M3) Internal Medicine (IM) clerkship OSCE scores was also explored. Lastly, conflicting evidence exists about the relationship between the amount of previous clinical experience and OSCE performance. Therefore, the relationship between M3 IM clerkship OSCE scores and the timing of the clerkship in the academic year was explored. Data from UNMC M2 OSCEs and M3 IM clerkship OSCEs were obtained for graduates of the 2013 and 2014 classes. Specifically, the following data points were collected: M2 fall OSCE total, M2 fall OSCE communication; M2 spring OSCE total, M2 spring OSCE communication; and M3 IM clerkship OSCE total percentages. Data were organized by class, M3 IM clerkship OSCE performance, and timing of the clerkship. Microsoft Excel and SPSS were used for data organization and analysis. Of the 245 records, 229 (93.5%) had data points for all metrics of interest. Significant differences between the classes of 2013 and 2014 existed for average M2 spring total, M2 spring communication, and M3 IM clerkship OSCEs. Retrospectively, there were no differences in M2 OSCE performances based on how students scored on the M3 IM clerkship OSCE. M3 IM clerkship OSCE performance improved for those students who completed the clerkship last in the academic year. There were inconsistencies in OSCE performances between the classes of 2013 and 2014, but more information is needed to determine if this is because of testing variability or heterogeneity

  1. Awarding global grades in OSCEs: evaluation of a novel eLearning resource for OSCE examiners.

    Science.gov (United States)

    Gormley, Gerard J; Johnston, Jenny; Thomson, Clare; McGlade, Kieran

    2012-01-01

    A novel online resource has been developed to aid OSCE examiner training comprising a series of videos of OSCE performances that allow inter-examiner comparison of global grade decisions. To evaluate this training resource in terms of usefulness and ability to improve examiner confidence in awarding global grades in OSCEs. Data collected from the first 200 users included global grades awarded, willingness to change grades following peer comparison and confidence in awarding grades before and after training. Most (86.5%) agreed that the resource was useful in developing global grade scoring ability in OSCEs, with a significant improvement in confidence in awarding grades after using the training package (p<0.001). This is a useful and effective online training package. As an adjunct to traditional training it offers a practical solution to the problem of availability of examiners.

  2. Taking OSCE examiner training on the road: reaching the masses

    Directory of Open Access Journals (Sweden)

    Katharine Reid

    2016-09-01

    Full Text Available Background: To ensure the rigour of objective structured clinical examinations (OSCEs in assessing medical students, medical school educators must educate examiners with a view to standardising examiner assessment behaviour. Delivering OSCE examiner training is a necessary yet challenging part of the OSCE process. A novel approach to implementing training for current and potential OSCE examiners was trialled by delivering large-group education sessions at major teaching hospitals. Methods: The ‘OSCE Roadshow’ comprised a short training session delivered in the context of teaching hospital ‘Grand Rounds’ to current and potential OSCE examiners. The training was developed to educate clinicians about OSCE processes, clarify the examiners’ role and required behaviours, and to review marking guides and mark allocation in an effort to standardise OSCE processes and encourage consistency in examiner marking behaviour. A short exercise allowed participants to practise marking a mock OSCE to investigate examiner marking behaviour after the training. Results: OSCE Roadshows at four metropolitan and one rural teaching hospital were well received and well attended by 171 clinicians across six sessions. Unexpectedly, medical students also attended in large numbers (n=220. After training, participants’ average scores for the mock OSCE clustered closely around the ideal score of 28 (out of 40, and the average scores did not differ according to the levels of clinical experience. Conclusion: The OSCE Roadshow demonstrated the potential of brief familiarisation training in reaching large numbers of current and potential OSCE examiners in a time and cost-effective manner to promote standardisation of OSCE processes.

  3. Relative source comparison of the NPE to underground nuclear explosions at local distances

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.T. [Lawrence Livermore National Lab., CA (United States)

    1994-12-31

    The Non-Proliferation Experiment (NPE) provides an opportunity to compare broadband characteristics of chemical to nuclear explosions at a group of local stations (4 to 40 km distant). The locations for these stations were established on bedrock to record a small partially decoupled nuclear explosion and two nearby nuclear experiments, all shots within {open_quotes}N{close_quotes} Tunnel on Rainier Mesa, Area 12. These sites were also occupied to record aftershocks from the Little Skull Mountain earthquake and chemical explosions from the USGS Sierra Experiment. To minimize calibration errors during this period, redundant instrumentation were used for each event. THe analysis emphasizes the source characteristics of the different explosions. The 300-lb chemical calibration explosion allows removal of path effects from each explosion. The NPE and nearby experiments produce very similar waveforms. The decoupled nuclear explosion and the 300-lb chemical calibration explosion show higher frequency content consistent with a higher corner frequency for the sources.

  4. Kremlin's OSCE Ministerial Council-related demarches / Rokas M. Tracevskis

    Index Scriptorium Estoniae

    Tracevskis, Rokas M.

    2011-01-01

    Detsembril alguses Vilniuses toimunud OSCE kohtumisel kritiseeris USA riigisekretär Hillary Clinton Venemaa parlamendivalimiste korraldamist. Venemaa peaminister Vladimir Putin ütles, et USA riigisekretäri kõne saatis Vene opositsioonile tegutsemissignaali. Venemaa välisministri Sergei Lavrovi ja Leedu välisministri Audronius Azubalise ebasõbralikust kohtumisest. Venemaa blokeeris OSCE-s internetivabaduse kaitsele suunatud deklaratsiooni

  5. Rasch analysis on OSCE data : An illustrative example.

    Science.gov (United States)

    Tor, E; Steketee, C

    2011-01-01

    The Objective Structured Clinical Examination (OSCE) is a widely used tool for the assessment of clinical competence in health professional education. The goal of the OSCE is to make reproducible decisions on pass/fail status as well as students' levels of clinical competence according to their demonstrated abilities based on the scores. This paper explores the use of the polytomous Rasch model in evaluating the psychometric properties of OSCE scores through a case study. The authors analysed an OSCE data set (comprised of 11 stations) for 80 fourth year medical students based on the polytomous Rasch model in an effort to answer two research questions: (1) Do the clinical tasks assessed in the 11 OSCE stations map on to a common underlying construct, namely clinical competence? (2) What other insights can Rasch analysis offer in terms of scaling, item analysis and instrument validation over and above the conventional analysis based on classical test theory? The OSCE data set has demonstrated a sufficient degree of fit to the Rasch model (Χ(2) = 17.060, DF=22, p=0.76) indicating that the 11 OSCE station scores have sufficient psychometric properties to form a measure for a common underlying construct, i.e. clinical competence. Individual OSCE station scores with good fit to the Rasch model (p > 0.1 for all Χ(2) statistics) further corroborated the characteristic of unidimensionality of the OSCE scale for clinical competence. A Person Separation Index (PSI) of 0.704 indicates sufficient level of reliability for the OSCE scores. Other useful findings from the Rasch analysis that provide insights, over and above the analysis based on classical test theory, are also exemplified using the data set. The polytomous Rasch model provides a useful and supplementary approach to the calibration and analysis of OSCE examination data.

  6. Hubungan Tingkat Kecemasan dalam Menghadapi Objective Structured Clinical Examination (OSCE dengan Kelulusan OSCE pada Mahasiswa Fakultas Kedokteran Universitas Andalas

    Directory of Open Access Journals (Sweden)

    Dinda Putri Amir

    2016-01-01

    Full Text Available AbstrakKecemasan adalah normal terjadi dalam kehidupan, namun kecemasan dapat menjadi abnormal jika respons terhadap stimulus berlebihan. Pada mahasiswa, kecemasan berpengaruh terhadap proses pendidikan. OSCE merupakan salah satu bagian dari ujian komprehensif yang menguji keterampilan medis mahasiswa yang akan memasuki kepaniteraan klinik. Ujian ini hampir sama dengan ujian skills lab, tapi materi ujian lebih banyak dan setting ujian juga berbeda sehingga situasi tersebut menimbulkan kecemasan pada mahasiswa menjelang OSCE. Tujuan penelitian ini adalah menentukan hubungan tingkat kecemasan dalam menghadapi OSCE dengan kelulusan OSCE pada mahasiwa FK Unand. Jenis penelitian ini adalah deskriptif analitik dengan sampel sebanyak 34 orang. Data diperoleh melalui wawancara kepada peserta OSCE menggunakan kuesioner Hamilton Rating Scale for Anxiety (HRS-A dan Bagian Akademik FK Unand yang selanjutnya dianalisis melalui uji korelasi Gamma dan Somers’d. Hasil penelitian ini didapatkan nilai koefisien korelasi (r sebesar -0,106 dan nilai signifikansi p>0,05. Berdasarkan hasil penelitian dapat disimpulkan bahwa tidak terdapat hubungan yang bermakna antara tingkat kecemasan dalam menghadapi OSCE dengan kelulusan OSCE pada mahasiwa FK Unand.Kata kunci: kecemasan, ujian, OSCE, HRS-A AbstractAnxiety normally occurs in life, but anxiety can become abnormal if the response to the stimulus is excessive. In student, anxiety affects the educational process. OSCE is a part of comprehensive exam that examine medical skills of the students who will enter their clinical stage. Although this exam is similiar like skills lab exam but the matters of exam is more complex and the setting of exam is different too, so these situations cause anxiety in students toward OSCE. The objective of this study was to determine the correlation between anxiety level in facing OSCE to students’ graduation of OSCE in Faculty of Medicine Andalas University. This study was a

  7. Implementation of an OSCE at Kaohsiung Medical University

    Directory of Open Access Journals (Sweden)

    Yu-Sheng Huang

    2007-04-01

    Full Text Available The Objective Structured Clinical Examination (OSCE, a tool to objectively and fairly assess medical students' clinical competences, has become widely used in medical education worldwide. However, most medical schools in Taiwan have just begun to adopt this assessment method. In 2003, Kaohsiung Medical University (KMU established the first standardized patient (SP program in Taiwan and applied SPs with an OSCE. This study reports the process of the implementation of an OSCE at KMU, which includes collecting information, visiting leading clinical skills centers, consulting medical educators from other countries, holding international conferences, establishing an OSCE committee, writing cases, training SPs, administrating the OSCE, and receiving feedback from medical students. Most students were satisfied with the assessment and appreciated the learning experience. Based on the experience in 2003, the OSCE committee decided to incorporate the OSCE into the medical curriculum as a measure to assess medical students' clinical competences. In addition to assessing medical students' clinical competence, the OSCE can also be applied to other professional health education, such as dentistry, nursing, and pharmacy. We are currently sharing our experience with other colleges at KMU.

  8. Increased Authenticity in Practical Assessment Using Emergency Case OSCE Stations

    Science.gov (United States)

    Ruesseler, Miriam; Weinlich, Michael; Byhahn, Christian; Muller, Michael P.; Junger, Jana; Marzi, Ingo; Walcher, Felix

    2010-01-01

    In case of an emergency, a fast and structured patient management is crucial for patient's outcome. The competencies needed should be acquired and assessed during medical education. The objective structured clinical examination (OSCE) is a valid and reliable assessment format to evaluate practical skills. However, traditional OSCE stations examine…

  9. Rasch analysis on OSCE data : An illustrative example

    Directory of Open Access Journals (Sweden)

    Tor E

    2011-06-01

    Full Text Available BackgroundThe Objective Structured Clinical Examination (OSCE is awidely used tool for the assessment of clinical competencein health professional education. The goal of the OSCE is tomake reproducible decisions on pass/fail status as well asstudents’ levels of clinical competence according to theirdemonstrated abilities based on the scores. This paperexplores the use of the polytomous Rasch model inevaluating the psychometric properties of OSCE scoresthrough a case study.MethodThe authors analysed an OSCE data set (comprised of 11stations for 80 fourth year medical students based on thepolytomous Rasch model in an effort to answer tworesearch questions: (1 Do the clinical tasks assessed in the11 OSCE stations map on to a common underlyingconstruct, namely clinical competence? (2 What otherinsights can Rasch analysis offer in terms of scaling, itemanalysis and instrument validation over and above theconventional analysis based on classical test theory?ResultsThe OSCE data set has demonstrated a sufficient degree offit to the Rasch model (χ2 = 17.060, DF=22, p=0.76indicating that the 11 OSCE station scores have sufficientpsychometric properties to form a measure for a commonunderlying construct, i.e. clinical competence. IndividualOSCE station scores with good fit to the Rasch model (p >0.1 for all χ2 statistics further corroborated thecharacteristic of unidimensionality of the OSCE scale forclinical competence. A Person Separation Index (PSI of0.704 indicates sufficient level of reliability for the OSCEscores. Other useful findings from the Rasch analysis thatprovide insights, over and above the analysis based onclassical test theory, are also exemplified using the data set.ConclusionThe polytomous Rasch model provides a useful andsupplementary approach to the calibration and analysis ofOSCE examination data.

  10. Low-frequency electromagnetic measurements at the NPE and Hunter`s Trophy: A comparison

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, J.J. [Lawrence Livermore National Lab., CA (United States)

    1994-12-31

    Sensors and recorders were deployed for both the Non-Proliferative Experiment (NPE) and Hunter`s Trophy to measure low-frequency (1-30 Hz) electric and magnetic fields accompanying the detonation. Two stations were used for each event, located at a slant range of about 500 m, with measurements of orthogonal horizontal electric field and orthogonal horizontal and vertical magnetic field. Signals were recorded digitally with at 200 Hz sampling rate. Separate magnetic and electric signals were recorded which can be related both to the detonation and the arrival of the shock wave. The detonation time signal from the nuclear explosion is a relatively short pulse occurring with no detectable delay (within 0.5 ms) ranging from 11-19 ms after the detonation time. The cause of the initial electromagnetic signal for both chemical and nuclear explosions is unknown; the differences between the NPE and Hunter`s Trophy results may be related to the different mechanisms involved with plasma generation between nuclear and chemical explosions.

  11. Objective structured clinical examination (OSCE in pharmacy education - a trend

    Directory of Open Access Journals (Sweden)

    Shirwaikar A

    2015-12-01

    Full Text Available Pharmacy education has undergone a radical change as it evolves towards becoming a more patient oriented profession. With a greater emphasis on problem based teaching and competency, the Objective Structured Clinical Examination (OSCE, supported by its reliability and validity became the gold standard for the evaluation of clinical skills of undergraduate students of medicine and pharmacy worldwide. Core competency evaluation has become a mandatory and critical norm for accountability of educational objectives as the traditional testing tools cannot evaluate clinical competence. Interpersonal and communication skills, professional judgment, skills of resolution etc., may be best assessed through a well- structured OSCE in comparison to oral examinations, multiple choice tests and other methods of assessment. Though OSCEs as an objective method of evaluation offer several advantages to both students and teachers, it also has disadvantages and pitfalls in implementation. This article reviews the OSCE as a trend in pharmacy education.

  12. Russia coordinates new broadside against OSCE / Liz Fuller

    Index Scriptorium Estoniae

    Fuller, Liz

    2004-01-01

    SRÜ maade poolt 8. juulil 2004 Viinis tehtud avaldusest, mille kohaselt sekkub Euroopa Julgeoleku- ja Koostööorganisatsioon (OSCE) riikide siseasjadesse ning rakendab topeltstandardeid. Avaldusega ei ühinenud Gruusia ja Aserbaidžaan

  13. Item Analysis to Improve Reliability for an Internal Medicine Undergraduate OSCE

    Science.gov (United States)

    Auewarakul, Chirayu; Downing, Steven M.; Praditsuwan, Rungnirand; Jaturatamrong, Uapong

    2005-01-01

    Utilization of objective structured clinical examinations (OSCEs) for final assessment of medical students in Internal Medicine requires a representative sample of OSCE stations. The reliability and generalizability of OSCE scores provides validity evidence for OSCE scores and supports its contribution to the final clinical grade of medical…

  14. The use of the OSCE in postgraduate education.

    Science.gov (United States)

    Arnold, R C; Walmsley, A D

    2008-08-01

    The Objective Structured Clinical Examination (OSCE) is a method of assessing the clinical skills of undergraduates in medicine, dentistry and other health sciences and is employed increasingly in postgraduate education. To describe the application of the OSCE to the development of Lifelong Learning and Continuing Professional Development (CPD) for General Dental Practitioners (GDPs). A postgraduate course was designed as an OSCE for GDPs. The OSCE comprised 12 stations covering different aspects of general dentistry. After an introductory seminar outlining the aim of the course, the participants spent 7 min at each station. Each question or task required 10 answers and was designed to highlight areas of weakness or interest and to stimulate further study of the presenting topic. Solutions and answers were provided at each station for self-assessment along with a list of locally presented courses related to that subject. Participants were invited to leave contact details and to make suggestions for future postgraduate courses. The final session consisted of a group discussion and participants were invited to complete an evaluation form to express opinions on the course. The evaluation demonstrated that most candidates found participation in the OSCE stimulated their interest in CPD. The OSCE also highlighted areas of weakness in knowledge of certain clinical procedures. Group discussion confirmed that practitioners found the hands-on component valuable and that they were likely to participate in further OSCEs to enhance their CPD. Suggestions received during the discussion were used to modify the course. The OSCE course fulfilled its aim of assisting practitioners to organise their CPD. The reflective nature of the course was helpful in evaluating clinical knowledge and the unique multidisciplinary style fulfilled its objective in promoting thoughts regarding future study.

  15. Feedback in the OSCE: What Do Residents Remember?

    Science.gov (United States)

    Humphrey-Murto, Susan; Mihok, Marika; Pugh, Debra; Touchie, Claire; Halman, Samantha; Wood, Timothy J

    2016-01-01

    The move to competency-based education has heightened the importance of direct observation of clinical skills and effective feedback. The Objective Structured Clinical Examination (OSCE) is widely used for assessment and affords an opportunity for both direct observation and feedback to occur simultaneously. For feedback to be effective, it should include direct observation, assessment of performance, provision of feedback, reflection, decision making, and use of feedback for learning and change. If one of the goals of feedback is to engage students to think about their performance (i.e., reflection), it would seem imperative that they can recall this feedback both immediately and into the future. This study explores recall of feedback in the context of an OSCE. Specifically, the purpose of this study was to (a) determine the amount and the accuracy of feedback that trainees remember immediately after an OSCE, as well as 1 month later, and (b) assess whether prompting immediate recall improved delayed recall. Internal medicine residents received 2 minutes of verbal feedback from physician examiners in the context of an OSCE. The feedback was audio-recorded and later transcribed. Residents were randomly allocated to the immediate recall group (immediate-RG; n = 10) or the delayed recall group (delayed-RG; n = 8). The immediate-RG completed a questionnaire prompting recall of feedback received immediately after the OSCE, and then again 1 month later. The delayed-RG completed a questionnaire only 1 month after the OSCE. The total number and accuracy of feedback points provided by examiners were compared to the points recalled by residents. Results comparing recall at 1 month between the immediate-RG and the delayed-RG were also studied. Physician examiners provided considerably more feedback points (M = 16.3) than the residents recalled immediately after the OSCE (M = 2.61, p feedback points recalled upon completion of the OSCE (2.61) compared to 1 month later (M = 1

  16. Low-level light therapy potentiates NPe6-mediated photodynamic therapy in a human osteosarcoma cell line via increased ATP.

    Science.gov (United States)

    Tsai, Shang-Ru; Yin, Rui; Huang, Ying-Ying; Sheu, Bor-Ching; Lee, Si-Chen; Hamblin, Michael R

    2015-03-01

    Low-level light therapy (LLLT) is used to stimulate healing, reduce pain and inflammation, and preserve tissue from dying. LLLT has been shown to protect cells in culture from dying after various cytotoxic insults, and LLLT is known to increase the cellular ATP content. Previous studies have demonstrated that maintaining a sufficiently high ATP level is necessary for the efficient induction and execution of apoptosis steps after photodynamic therapy (PDT). We asked whether LLLT would protect cells from cytotoxicity due to PDT, or conversely whether LLLT would enhance the efficacy of PDT mediated by mono-l-aspartyl chlorin(e6) (NPe6). Increased ATP could lead to enhanced cell uptake of NPe6 by the energy dependent process of endocytosis, and also to more efficient apoptosis. In this study, human osteosarcoma cell line MG-63 was subjected to 1.5J/cm(2) of 810nm near infrared radiation (NIR) followed by addition of 10μM NPe6 and after 2h incubation by 1.5J/cm(2) of 652nm red light for PDT. PDT combined with LLLT led to higher cell death and increased intracellular reactive oxygen species compared to PDT alone. The uptake of NPe6 was moderately increased by LLLT, and cellular ATP was increased. The mitochondrial respiratory chain inhibitor antimycin A abrogated the LLLT-induced increase in cytotoxicity. Taken together, these results demonstrate that LLLT potentiates NPe6-mediated PDT via increased ATP synthesis and is a potentially promising strategy that could be applied in clinical PDT. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Analysis of the exclusive final state npe"+e"- in the quasi-free np reaction

    International Nuclear Information System (INIS)

    Adamczewski-Musch, J.; Heinz, T.; Holzmann, R.; Koenig, I.; Koenig, W.; Kolb, B.W.; Markert, J.; Pechenov, V.; Pietraszko, J.; Schwab, E.; Sturm, C.; Traxler, M.; Wendisch, C.; Zumbruch, P.; Arnold, O.; Berger-Chen, J.C.; Epple, E.; Fabbietti, L.; Lalik, R.; Lapidus, K.; Mihaylov, D.M.; Muenzer, R.; Wirth, J.; Atomssa, E.T.; Belounnas, A.; Hennino, T.; Liu, T.; Moriniere, E.; Ramstein, B.; Rosier, P.; Behnke, C.; Blume, C.; Froehlich, I.; Kardan, B.; Lorenz, M.; Michel, J.; Muentz, C.; Pechenova, O.; Scheib, T.; Schuldes, H.; Sellheim, P.; Stroebele, H.; Wiebusch, M.G.; Belyaev, A.; Chernenko, S.; Fateev, O.; Ierusalimov, A.; Kurilkin, A.; Kurilkin, P.; Ladygin, V.; Zanevsky, Y.; Biernat, J.; Dybczak, A.; Korcyl, G.; Nowakowski, K.; Palka, M.; Przygoda, W.; Salabura, P.; Strzempek, P.; Blanco, A.; Bordalo, P.; Fonte, P.; Franco, C.; Lopes, L.; Mangiarotti, A.; Ramos, S.; Silva, L.; Boehmer, M.; Friese, J.; Gernhaeuser, R.; Kunz, T.; Maier, L.; Maurus, S.; Siebenson, J.; Chlad, L.; Kugler, A.; Rodriguez-Ramos, P.; Sobolev, Yu.G.; Svoboda, O.; Tlusty, P.; Wagner, V.; Deveaux, C.; Hoehne, C.; Kuehn, W.; Mahmoud, T.; Metag, V.; Dreyer, J.; Kaempfer, B.; Kotte, R.; Naumann, L.; Filip, P.; Hlavac, S.; Spataro, S.; Galatyuk, T.; Garzon, J.A.; Golubeva, M.; Guber, F.; Ivashkin, A.; Karavicheva, T.; Kurepin, A.; Morozov, S.; Petukhov, O.; Reshetin, A.; Sadovsky, A.; Usenko, E.; Gumberidze, M.; Kornakov, G.; Rost, A.; Seck, F.; Harabasz, S.; Lebedev, A.; Parpottas, Y.; Petousis, V.; Tsertos, H.; Scozzi, F.; Stroth, J.; Sarantsev, A.V.

    2017-01-01

    We report on the investigation of dielectron production in tagged quasi-free neutron-proton collisions by using a deuteron beam of kinetic energy 1.25 GeV/u impinging on a liquid hydrogen target. Our measurements with HADES confirm a significant excess of e"+e"- pairs above the π"0 mass in the exclusive channel dp → npe"+e"-(p_s_p_e_c_t) as compared to the exclusive channel ppe"+e"- measured in proton-proton collisions at the same energy. That excess points to different bremsstrahlung production mechanisms. Two models were evaluated for the role of the charged pion exchange between nucleons and double-Δ excitation combined with intermediate ρ-meson production. Differential cross sections as a function of the e"+e"- invariant mass and of the angles of the virtual photon, proton and electrons provide valuable constraints and encourage further investigations on both experimental and theoretical sides. (orig.)

  18. Detection Learning Style Vark For Out Of School Children (OSC)

    Science.gov (United States)

    Amran, Ali; Desiani, Anita; Hasibuan, MS

    2017-04-01

    Learning style is different for every learner especially for out of school children or OSC. They are not like formal students, they are learners but they don’t have a teacher as a guide for learning. E-learning is one of the solutions to help OSC to get education. E-learning should have preferred learning styles of learners. Data for identifying the learning style in this study were collected with a VARK questionnaire from 25 OSC in junior high school level from 5 municipalities in Palembang. The validity of the questionnaire was considered on basis of experts’ views and its reliability was calculated by using Cronbach’s alpha coefficients (α=0.68). Overall, 55% preferred to use a single learning style (Uni-modal). Of these, 27,76% preferred Aural, 20,57% preferred Reading Writing, 33,33% preferred Kinaesthetic and 23,13% preferred Visual. 45% of OSC preferred more than one style, 30% chose two-modes (bimodal), and 15% chose three-modes (tri-modal). The Most preferred Learning style of OSC is kinaesthetic learning. Kinaesthetic learning requires body movements, interactivities, and direct contacts with learning materials, these things can be difficult to implement in eLearning, but E-learning should be able to adopt any learning styles which are flexible in terms of time, period, curriculum, pedagogy, location, and language.

  19. OSCEs for undergraduate clinical examination in orthopaedics: inter ...

    African Journals Online (AJOL)

    ... D (Group 2) was 8.625. The p-value was 0.001148 (95% confidence interval). Conclusion: There was statistically significant inter-examiner variability. We recommend that for all OSCE exams, examiners be paired with a deliberate attempt to pair a “Hawk” with a “Dove”. Statistical correction of biases is also recommended.

  20. Modeling the NPE with finite sources and empirical Green`s functions

    Energy Technology Data Exchange (ETDEWEB)

    Hutchings, L.; Kasameyer, P.; Goldstein, P. [Lawrence Livermore National Lab., CA (United States)] [and others

    1994-12-31

    In order to better understand the source characteristics of both nuclear and chemical explosions for purposes of discrimination, we have modeled the NPE chemical explosion as a finite source and with empirical Green`s functions. Seismograms are synthesized at four sties to test the validity of source models. We use a smaller chemical explosion detonated in the vicinity of the working point to obtain empirical Green`s functions. Empirical Green`s functions contain all the linear information of the geology along the propagation path and recording site, which are identical for chemical or nuclear explosions, and therefore reduce the variability in modeling the source of the larger event. We further constrain the solution to have the overall source duration obtained from point-source deconvolution results. In modeling the source, we consider both an elastic source on a spherical surface and an inelastic expanding spherical volume source. We found that the spherical volume solution provides better fits to observed seismograms. The potential to identify secondary sources was examined, but the resolution is too poor to be definitive.

  1. Southern Sierra Nevada Continental Dynamics Project: 1993 field observations of the NPE

    Energy Technology Data Exchange (ETDEWEB)

    Keller, G.R. [Univ. of Texas, El Paso, TX (United States); Malin, P.E. [Duke Univ., Durham, NC (United States); Ruppert, S.D. [LLNL, Livermore, CA (United States)

    1994-12-31

    The Southern Sierra Nevada Continental Dynamics Project is a multidisciplinary, multi-institutional investigation of the cause of the uplift of the Sierra Nevada and its relationship to extension in the adjacent Basin and Range. A broad range of geologic and geophysical data have been collected as part of this project. These data include both passive and active seismic measurements, as well as gravity and magnetotelluric observations. Three seismic refraction/wide-angle reflection profiles were recorded: (1) a 325-km-long, north-south profile extending from just east of Mono Lake south across the Garlock fault, (2) a 400-km-long, east-west profile extending from Death Valley west across the Sierra Nevada to near the San Andreas fault, and (3) a 480-km-long, east-west profile deployed for the NPE. This profile extended from Beatty, Nevada, west across the Sierra Nevada along the previously recorded east-west profile and continued nearly to the Pacific Ocean. Up to 675 seismic recorders were deployed for each profile. These data are allowing us to develop refined models of the crustal and upper mantle structure of the southern Sierra Nevada and to evaluate alternative hypotheses for its uplift and for Basin and Range extension. They also provide insight into the propagation of regional phases across complex structures.

  2. USA ja Venemaa ristasid piike OSCE tuleviku pärast / Ahto Lobjakas

    Index Scriptorium Estoniae

    Lobjakas, Ahto, 1970-

    2006-01-01

    OSCE välisministrite kohtumiselt ei jõutud organisatsiooni tulevikus kokkuleppele. Kui USA nõuab, et OSCE-d tuleb tugevdada demokraatia edendajana ning valimiste aususe tagaja ja inimõiguste kaitsjana, siis Venemaa näeb sellises suunas liigset sekkumist liikmesriikide siseasjadesse

  3. OSCE vs. TEM: Different approaches to assess clinical skills of nursing students

    Directory of Open Access Journals (Sweden)

    Prasuna Jelly

    2017-01-01

    Full Text Available Introduction: Nurses are trained with specific clinical skills, and objective structured clinical examination (OSCE could be a better approach to assess clinical skills of nursing students. Materials and Methods: A comparative study was conducted by observational checklist regarding antenatal care and opinionnaire on the usefulness of OSCE and tradition evaluation method (TEM was used to assess the clinical skills and to get opinion. Results: The mean score of OSCE was more than TEM and the difference was statistically significant (P < 0.001. The opinion of students regarding the usefulness of OSCE was higher than TEM. Conclusions: The study concluded that implementing OSCE will overweigh the advantages of the TEM.

  4. Nurse educators’ perceptions of OSCE as a clinical evaluation method

    Directory of Open Access Journals (Sweden)

    MM Chabeli

    2001-09-01

    Full Text Available The South African Qualifications Authority, and the South African Nursing Council are in pursuit of quality nursing education to enable the learners to practise as independent and autonomous practitioners. The educational programme should focus on the facilitation of critical and reflective thinking skills that will help the learner to make rational decisions and solve problems. A way of achieving this level of functioning is the use of assessment and evaluation methods that measure the learners’ clinical competence holistically. This article is focused on the perceptions of twenty nurse educators, purposively selected from three Nursing Colleges affiliated to a university in Gauteng, regarding the use of OSCE (Objective Structured Clinical Examination as a clinical evaluation method within a qualitative and descriptive research strategy. Three focus group interviews were conducted in different sessions. A descriptive content analysis was used. Trustworthiness was ensured by using Lincoln and Guba’s model (1985. The results revealed both positive and negative aspects of OSCE as a clinical evaluation method with regard to: administrative aspects; evaluators; learners; procedures/instruments and evaluation. The conclusion drawn from the related findings is that OSCE does not measure the learners’ clinical competence holistically. It is therefore recommended that the identified negative perception be taken as challenges faced by nurse educators and that the positive aspects be strengthened. One way of meeting these recommendations is the use of varied alternative methods for clinical assessment and evaluation that focus on the holistic measurement of the learners’ clinical competence.

  5. Application of best practice guidelines for OSCEs-An Australian evaluation of their feasibility and value.

    Science.gov (United States)

    Mitchell, Marion L; Henderson, Amanda; Jeffrey, Carol; Nulty, Duncan; Groves, Michele; Kelly, Michelle; Knight, Sabina; Glover, Pauline

    2015-05-01

    Objective Structured Clinical Examinations (OSCEs) are widely used in health professional education and should be based on sound pedagogical foundations. The aim of this study is to evaluate the feasibility and utility of using Best Practice Guidelines (BPGs) within an OSCE format in a broad range of tertiary education settings with under-graduate and post-graduate nursing and midwifery students. We evaluated how feasible it was to apply the BPGs to modify OSCEs in a course; students' perspective of the OSCE; and finally, if the BPG-revised OSCEs better prepared students for clinical practice when compared with the original OSCEs. A mixed method with surveys, focus groups and semi-structured interviews evaluated the BPGs within an OSCE. Four maximally different contexts across four sites in Australia were used. Participants included lecturers and undergraduate nursing students in high and low fidelity simulation settings; under-graduate midwifery students; and post-graduate rural and remote area nursing students. 691 students participated in revised OSCEs. Surveys were completed by 557 students; 91 students gave further feedback through focus groups and 14 lecturers participated in interviews. At all sites the BPGs were successfully used to modify and implement OSCEs. Students valued the realistic nature of the modified OSCEs which contributed to students' confidence and preparation for clinical practice. The lecturers considered the revised OSCEs enhanced student preparedness for their clinical placements. The BPGs have a broad applicability to OSCEs in a wide range of educational contexts with improved student outcomes. Students and lecturers identified the revised OSCEs enhanced student preparation for clinical practice. Subsequent examination of the BPGs saw further refinement to a set of eight BPGs that provide a sequential guide to their application in a way that is consistent with best practice curriculum design principles. Copyright © 2015 Elsevier Ltd

  6. Enhancing OSCE preparedness with video exemplars in undergraduate nursing students. A mixed method study.

    Science.gov (United States)

    Massey, D; Byrne, J; Higgins, N; Weeks, B; Shuker, M-A; Coyne, E; Mitchell, M; Johnston, A N B

    2017-07-01

    Objective structured clinical examinations (OSCEs) are designed to assess clinical skill performance and competency of students in preparation for 'real world' clinical responsibilities. OSCEs are commonly used in health professional education and are typically associated with high levels of student anxiety, which may present a significant barrier to performance. Students, including nursing students, have identified that flexible access to exemplar OSCEs might reduce their anxiety and enable them to better prepare for such examinations. To implement and evaluate an innovative approach to preparing students for OSCEs in an undergraduate (registration) acute care nursing course. A set of digitized OSCE exemplars were prepared and embedded in the University-based course website as part of usual course learning activities. Use of the exemplars was monitored, pre and post OSCE surveys were conducted, and qualitative data were collected to evaluate the approach. OSCE grades were also examined. The online OSCE exemplars increased self-rated student confidence, knowledge, and capacity to prepare and provided clarity around assessment expectations. OSCE exemplars were accessed frequently and positively received; but did not impact on performance. Video exemplars aid student preparation for OSCEs, providing a flexible, innovative and clear example of the assessment process. Video exemplars improved self-rated student confidence and understanding of performance expectations, leading to increased engagement and reduced anxiety when preparing for the OSCE, but not overall OSCE performance. Such OSCE exemplars could be used to increase staff capacity and improve the quality of the student learning experience. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  7. ‘EU differentiation’ as a case of ‘Normative Power Europe’ (NPE) in the Israeli-Palestinian conflict

    DEFF Research Database (Denmark)

    Persson, Anders

    2018-01-01

    strategy has worked in the sense that it has created a normative, legal and in a few cases economic separation in the EU’s dealings with the internationally-recognised Israel and the non-recognised settlements, it has with some very minor, insignificant exceptions, not changed the realities on the ground......Opposition to Israel’s occupation and in particular its settlement enterprise on what the European Union (EU) perceives to be Palestinian/Syrian territories has been a consistent EC/EU policy since 1977 when what was then called the European Community (EC) issued its first declaration against...... the settlements. While there has been a long historical precedent for EU differentiation in the conflict, the ‘differentiation strategy’ was inofficially operationalized first in 2013. Using the theory of ‘Normative Power Europe’ (NPE) as a framework of analysis, this article argues that while the differentiation...

  8. Proceedings of the symposium on the Non-Proliferation Experiment (NPE): Results and implications for test ban treaties

    Energy Technology Data Exchange (ETDEWEB)

    Denny, M.D.; Stull, S.P. [eds.

    1994-12-31

    The large amounts of chemical explosives used worldwide in mining, quarrying, and civil engineering projects presents a challenge for policy makers molding a test ban, since their use could provide the necessary cover for a clandestine nuclear test. The Non-Proliferation Experiment (NPE) seeks to measure certain differences between an underground nuclear test and a chemical explosion in the same geology. Two chemical explosions were detonated at the Nevada Test Site to compare their signatures with previous nuclear tests. This conference presents results of these tests and discusses implications for test ban treaties. Conference papers are divided into the following sections: Background; Test preparations; EOS and code simulations; Rainier Mesa structure; Ground motion measurements; Non-seismic technologies; On-site inspection technologies; and a panel discussion. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  9. Theoretical Study on the Rational Design of Cyano-Substituted P3HT Materials for OSCs

    DEFF Research Database (Denmark)

    Qiu, Meng; Brandt, Rasmus Guldbæk; Niu, Yingli

    2015-01-01

    Calculations have been made regarding the strong electron-withdrawing cyano (-CN) group, which was introduced onto the backbone of poly(3-hexylthiophene) (P3HT), as an effective way to improve the parameters essential for the photovoltaic performance of organic solar cells (OSCs). The substitution...... useful information for better design strategy for OSCs....

  10. Assessing the Organizational Social Context (OSC) of Child Welfare Systems: Implications for Research and Practice

    Science.gov (United States)

    Glisson, Charles; Green, Philip; Williams, Nathaniel J.

    2012-01-01

    Objective: The study: (1) provides the first assessment of the a "priori" measurement model and psychometric properties of the Organizational Social Context (OSC) measurement system in a US nationwide probability sample of child welfare systems; (2) illustrates the use of the OSC in constructing norm-based organizational culture and climate…

  11. OSCE as a Summative Assessment Tool for Undergraduate Students of Surgery-Our Experience.

    Science.gov (United States)

    Joshi, M K; Srivastava, A K; Ranjan, P; Singhal, M; Dhar, A; Chumber, S; Parshad, R; Seenu, V

    2017-12-01

    Traditional examination has inherent deficiencies. Objective Structured Clinical Examination (OSCE) is considered as a method of assessment that may overcome many such deficits. OSCE is being increasingly used worldwide in various medical specialities for formative and summative assessment. Although it is being used in various disciplines in our country as well, its use in the stream of general surgery is scarce. We report our experience of assessment of undergraduate students appearing in their pre-professional examination in the subject of general surgery by conducting OSCE. In our experience, OSCE was considered a better assessment tool as compared to the traditional method of examination by both faculty and students and is acceptable to students and faculty alike. Conducting OSCE is feasible for assessment of students of general surgery.

  12. Student evaluation of an OSCE in paediatrics at the University of the West Indies, Jamaica

    Directory of Open Access Journals (Sweden)

    Branday J Michael

    2004-10-01

    Full Text Available Abstract Background The Faculty of Medical Sciences, University of the West Indies first implemented the Objective Structured Clinical Examination (OSCE in the final MB Examination in Medicine and Therapeutics during the 2000–2001 academic year. Simultaneously, the Child Health Department initiated faculty and student training, and instituted the OSCE as an assessment instrument during the Child Health (Paediatric clerkship in year 5. The study set out to explore student acceptance of the OSCE as part of an evaluation of the Child Health clerkship. Methods A self-administered questionnaire was completed by successive groups of students immediately after the OSCE at the end of each clerkship rotation. Main outcome measures were student perception of examination attributes, which included the quality of instructions and organisation, the quality of performance, authenticity and transparency of the process, and usefulness of the OSCE as an assessment instrument compared to other formats. Results There was overwhelming acceptance of the OSCE in Child Health with respect to the comprehensiveness (90%, transparency (87%, fairness (70% and authenticity of the required tasks (58–78%. However, students felt that it was a strong anxiety-producing experience. And concerns were expressed regarding the ambiguity of some questions and inadequacy of time for expected tasks. Conclusion Student feedback was invaluable in influencing faculty teaching, curriculum direction and appreciation of student opinion. Further psychometric evaluation will strengthen the development of the OSCE.

  13. The Dental School Interview As a Predictor of Dental Students' OSCE Performance.

    Science.gov (United States)

    Park, Sang E; Price, Mirissa D; Karimbux, Nadeem Y

    2018-03-01

    The aim of this study was to evaluate the use of the dental school admissions interview score as a noncognitive indicator of performance in predoctoral dental education, with specific attention to whether a correlation existed between the admissions interview scores and performance on the objective structured clinical examination (OSCE). The study population consisted of all 175 students in the Harvard School of Dental Medicine (HSDM) DMD Classes of 2012 through 2016. Data on students' gender and age on entering dental school were self-reported using their applications for admission to the HSDM DMD program. Data on students' OSCE scores for three examination sessions were collected from the Office of Dental Education. The results showed that the students' interview scores did not significantly correlate with OSCE performance on any of the three exams. Performance on the first and second OSCEs did, however, correlate with performance on the third OSCE (pinterview score. These results suggest that although the admissions interview scores can serve as an important resource in student selection, with the lack of association between interview and OSCE scores, it is possible that the communication skills required for the interview do not directly overlap with those required for OSCE success.

  14. Hubungan Self Assessment-Peer Assessment dengan Nilai Kelulusan OSCE Mahasiswa Fakultas Kedokteran Unisba

    Directory of Open Access Journals (Sweden)

    Santun Bhekti Rahimah

    2017-02-01

    Full Text Available Abstrak Objective structured clinical examination (OSCE adalah cara penilaian kompetensi klinik mahasiswa secara komprehensif dan konsisten serta dapat dijadikan media untuk meningkatkan hasil belajar. Feedback dapat dilakukan oleh mahasiswa itu sendiri (self assessment maupun mahasiswa lain yang satu level (peer assessment. Self dan peer assessment diharapkan akan meningkatkan kemampuan mahasiswa dalam melihat tujuan pembelajaran, meningkatkan rasa percaya diri, kemampuan berpikir kritis, dan bertindak tepat dalam menghadapi ujian. Tujuan penelitian ini melihat hubungan self assessment dan peer assessment dengan nilai kelulusan OSCE mahasiswa tingkat dua dan empat FK Unisba tahun akademik 2012/2013. Nilai hasil ujian OSCE yang dipergunakan adalah pada periode Desember 2012–Juni 2013. Self dan peer assessment dilaksanakan setelah ujian OSCE. Self assessment dilakukan oleh mahasiswa itu sendiri, sedangkan peer assessment didapatkan dari lima orang mahasiswa lain yang pernah berada dalam satu kelompok dengan subjek. Hasil penelitian menunjukkan untuk mahasiswa tingkat dua terdapat korelasi bermakna self assessment dan peer assessment dengan nilai OSCE (p<0,001, arah hubungan antara keduanya positif, serta kekuatan hubungan keduanya sedang (R=0,426. Pada mahasiswa tingkat empat terdapat korelasi bermakna antara self assessment dan nilai OSCE (p<0,001 dengan kekuatan hubungan keduanya sedang (R=0,451, serta terdapat korelasi yang bermakna antara penilaian peer assessment dan nilai OSCE. Simpulan, self assessment mempunyai korelasi positif terhadap nilai kelulusan OSCE pada mahasiswa tingkat dua dan tingkat empat, sedangkan peer assessment mempunyai korelasi positif dengan nilai kelulusan OSCE hanya pada mahasiswa tingkat dua. Self assessment mempunyai korelasi positif dengan peer assessment pada mahasiswa tingkat dua dan tingkat empat FK Unisba tahun akademik 2012/2013. Abstract Objective structured clinical examination (OSCE is a tools to assess

  15. Analysis of the exclusive final state npe{sup +}e{sup -} in the quasi-free np reaction

    Energy Technology Data Exchange (ETDEWEB)

    Adamczewski-Musch, J.; Heinz, T.; Holzmann, R.; Koenig, I.; Koenig, W.; Kolb, B.W.; Markert, J.; Pechenov, V.; Pietraszko, J.; Schwab, E.; Sturm, C.; Traxler, M.; Wendisch, C.; Zumbruch, P. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Arnold, O.; Berger-Chen, J.C.; Epple, E.; Fabbietti, L.; Lalik, R.; Lapidus, K.; Mihaylov, D.M.; Muenzer, R.; Wirth, J. [Excellence Cluster ' ' Origin and Structure of the Universe' ' , Garching (Germany); Technische Universitaet Muenchen, Physik Department E62, Garching (Germany); Atomssa, E.T.; Belounnas, A.; Hennino, T.; Liu, T.; Moriniere, E.; Ramstein, B.; Rosier, P. [Institut de Physique Nucleaire, CNRS-IN2P3, Univ. Paris-Sud, Universite Paris-Saclay, Orsay Cedex (France); Behnke, C.; Blume, C.; Froehlich, I.; Kardan, B.; Lorenz, M.; Michel, J.; Muentz, C.; Pechenova, O.; Scheib, T.; Schuldes, H.; Sellheim, P.; Stroebele, H.; Wiebusch, M.G. [Goethe-Universitaet, Institut fuer Kernphysik, Frankfurt (Germany); Belyaev, A.; Chernenko, S.; Fateev, O.; Ierusalimov, A.; Kurilkin, A.; Kurilkin, P.; Ladygin, V.; Zanevsky, Y. [Joint Institute of Nuclear Research, Dubna (Russian Federation); Biernat, J.; Dybczak, A.; Korcyl, G.; Nowakowski, K.; Palka, M.; Przygoda, W.; Salabura, P.; Strzempek, P. [Jagiellonian University of Cracow, Smoluchowski Institute of Physics, Krakow (Poland); Blanco, A.; Bordalo, P.; Fonte, P.; Franco, C.; Lopes, L.; Mangiarotti, A.; Ramos, S.; Silva, L. [LIP-Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Coimbra (Portugal); Boehmer, M.; Friese, J.; Gernhaeuser, R.; Kunz, T.; Maier, L.; Maurus, S.; Siebenson, J. [Technische Universitaet Muenchen, Physik Department E62, Garching (Germany); Chlad, L.; Kugler, A.; Rodriguez-Ramos, P.; Sobolev, Yu.G.; Svoboda, O.; Tlusty, P.; Wagner, V. [The Czech Academy of Sciences, Nuclear Physics Institute, Rez (Czech Republic); Deveaux, C.; Hoehne, C.; Kuehn, W.; Mahmoud, T.; Metag, V. [Justus Liebig Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Dreyer, J.; Kaempfer, B.; Kotte, R.; Naumann, L. [Helmholtz-Zentrum Dresden-Rossendorf, Institut fuer Strahlenphysik, Dresden (Germany); Filip, P.; Hlavac, S.; Spataro, S. [Slovak Academy of Sciences, Institute of Physics, Bratislava (Slovakia); Galatyuk, T. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Technische Universitaet Darmstadt, Darmstadt (Germany); Garzon, J.A. [Univ. de Santiago de Compostela, LabCAF. F. Fisica, Santiago de Compostela (Spain); Golubeva, M.; Guber, F.; Ivashkin, A.; Karavicheva, T.; Kurepin, A.; Morozov, S.; Petukhov, O.; Reshetin, A.; Sadovsky, A.; Usenko, E. [Russian Academy of Science, Institute for Nuclear Research, Moscow (Russian Federation); Gumberidze, M.; Kornakov, G.; Rost, A.; Seck, F. [Technische Universitaet Darmstadt, Darmstadt (Germany); Harabasz, S. [Jagiellonian University of Cracow, Smoluchowski Institute of Physics, Krakow (Poland); Technische Universitaet Darmstadt, Darmstadt (Germany); Lebedev, A. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Parpottas, Y.; Petousis, V.; Tsertos, H. [University of Cyprus, Department of Physics, Nicosia (Cyprus); Scozzi, F. [Technische Universitaet Darmstadt, Darmstadt (Germany); Institut de Physique Nucleaire, CNRS-IN2P3, Univ. Paris-Sud, Universite Paris-Saclay, Orsay Cedex (France); Stroth, J. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Goethe-Universitaet, Institut fuer Kernphysik, Frankfurt (Germany); Sarantsev, A.V. [NRC ' ' Kurchatov Institute' ' , PNPI, Gatchina (Russian Federation); Collaboration: HADES Collaboration

    2017-07-15

    We report on the investigation of dielectron production in tagged quasi-free neutron-proton collisions by using a deuteron beam of kinetic energy 1.25 GeV/u impinging on a liquid hydrogen target. Our measurements with HADES confirm a significant excess of e{sup +}e{sup -} pairs above the π{sup 0} mass in the exclusive channel dp → npe{sup +}e{sup -}(p{sub spect}) as compared to the exclusive channel ppe{sup +}e{sup -} measured in proton-proton collisions at the same energy. That excess points to different bremsstrahlung production mechanisms. Two models were evaluated for the role of the charged pion exchange between nucleons and double-Δ excitation combined with intermediate ρ-meson production. Differential cross sections as a function of the e{sup +}e{sup -} invariant mass and of the angles of the virtual photon, proton and electrons provide valuable constraints and encourage further investigations on both experimental and theoretical sides. (orig.)

  16. Student evaluation of an OSCE in General Medicine at Mamata Medical College, Andhra Pradesh

    Directory of Open Access Journals (Sweden)

    Dharma Rao V, Pramod Kumar Reddy M, Rajaneesh Reddy M, HanumiahA, Shyam Sunder P, Narasingha Reddy T, Kishore Babu SPV

    2014-04-01

    Full Text Available The assessment of student’s clinical competence is of paramount importance, and there are several means of evaluating student performance in medical examinations. The OSCE is an approach to student assessment in which aspects of clinical competence are evaluated in a comprehensive, consistent and structured manner with close attention to the objectivity of the process. The faculty of general medicine in collaboration with other clinical departments, Mamata Medical College, Khammam first implemented the objective structured clinical examination (OSCE in the final MBBS Part-II examination during the internal assessment examination for the 2011-2012 academic years. The study was set out to explore student acceptance of the OSCE as part of an evaluation of final MBBS students. A self-administered questionnaire was completed by successive groups of students immediately after the OSCE. Main outcome measures were student perception of examination attributes, which included the quality of instructions and organization, the quality of performance, authenticity and transparency of the process, and usefulness of the OSCE as an assessment instrument compared to other formats. There was an overwhelming acceptance of OSCE in general medicine with respect to comprehensiveness (90% transparency (90% & authenticity of required tasks. Students felt that it was a useful form of examination. Student’s feedback was invaluable in influencing faculty teaching curriculum direction and appreciation of student opinion and overall the students were agreeable with newer form of OSCE. The majority of the students felt that OSCE is a fair assessment tool compared to traditional long and short cases and it covers a wide range of knowledge and clinical skills in general medicine.

  17. Student reflections on learning cross-cultural skills through a 'cultural competence' OSCE.

    Science.gov (United States)

    Miller, Elizabeth; Green, Alexander R

    2007-05-01

    Medical schools use OSCEs (objective structured clinical examinations) to assess students' clinical knowledge and skills, but the use of OSCEs in the teaching and assessment of cross-cultural care has not been well described. To examine medical students' reflections on a cultural competence OSCE station as an educational experience. Students at Harvard Medical School in Boston completed a 'cultural competence' OSCE station (about a patient with uncontrolled hypertension and medication non-adherence). Individual semi-structured interviews were conducted with a convenience sample of twenty-two second year medical students, which were recorded, transcribed, and analysed. Students' reflections on what they learned as the essence of the case encompassed three categories: (1) eliciting the patient's perspective on their illness; (2) examining how and why patients take their medications and inquiring about alternative therapies; and (3) exploring the range of social and cultural factors associated with medication non-adherence. A cultural competence OSCE station that focuses on eliciting patients' perspectives and exploring medication non-adherence can serve as a unique and valuable teaching tool. The cultural competence OSCE station may be one pedagogic method for incorporating cross-cultural care into medical school curricula.

  18. A core competency-based objective structured clinical examination (OSCE) can predict future resident performance.

    Science.gov (United States)

    Wallenstein, Joshua; Heron, Sheryl; Santen, Sally; Shayne, Philip; Ander, Douglas

    2010-10-01

    This study evaluated the ability of an objective structured clinical examination (OSCE) administered in the first month of residency to predict future resident performance in the Accreditation Council for Graduate Medical Education (ACGME) core competencies. Eighteen Postgraduate Year 1 (PGY-1) residents completed a five-station OSCE in the first month of postgraduate training. Performance was graded in each of the ACGME core competencies. At the end of 18 months of training, faculty evaluations of resident performance in the emergency department (ED) were used to calculate a cumulative clinical evaluation score for each core competency. The correlations between OSCE scores and clinical evaluation scores at 18 months were assessed on an overall level and in each core competency. There was a statistically significant correlation between overall OSCE scores and overall clinical evaluation scores (R = 0.48, p competencies of patient care (R = 0.49, p competencies. An early-residency OSCE has the ability to predict future postgraduate performance on a global level and in specific core competencies. Used appropriately, such information can be a valuable tool for program directors in monitoring residents' progress and providing more tailored guidance. © 2010 by the Society for Academic Emergency Medicine.

  19. Interactions of oversulfated chondroitin sulfate (OSCS) from different sources with unfractionated heparin.

    Science.gov (United States)

    Gray, Angel; Litinas, Evangelos; Jeske, Walter; Fareed, Jawed; Hoppensteadt, Debra

    2012-01-01

    In 2008, oversulfated chondroitin sulfate (OSCS) was identified as the main contaminant in recalled heparin. Oversulfated chondroitin sulfate can be prepared from bovine (B), porcine (P), shark (Sh), or skate (S) origin and may produce changes in the antithrombotic, bleeding, and hemodynamic profile of heparins. This study examines the interactions of various OSCSs on heparin in animal models of thrombosis and bleeding, as well as on the anticoagulant and antiprotease effects in in vitro assays. Mixtures of 70% unfractionated heparin (UFH) with 30% OSCS from different sources were tested. In the in vitro activated partial thromboplastin time (aPTT) assay, all contaminant mixtures showed a decrease in clotting times. In addition, a significant increase in bleeding time compared to the control (UFH/saline) was observed. In the thrombosis model, no significant differences were observed. The OSCSs significantly increased anti-Xa activity in ex vivo blood samples. These results indicate that various sources of OSCS affect the hemostatic properties of heparin.

  20. Evaluation of the OSC-TV iterative reconstruction algorithm for cone-beam optical CT.

    Science.gov (United States)

    Matenine, Dmitri; Mascolo-Fortin, Julia; Goussard, Yves; Després, Philippe

    2015-11-01

    The present work evaluates an iterative reconstruction approach, namely, the ordered subsets convex (OSC) algorithm with regularization via total variation (TV) minimization in the field of cone-beam optical computed tomography (optical CT). One of the uses of optical CT is gel-based 3D dosimetry for radiation therapy, where it is employed to map dose distributions in radiosensitive gels. Model-based iterative reconstruction may improve optical CT image quality and contribute to a wider use of optical CT in clinical gel dosimetry. This algorithm was evaluated using experimental data acquired by a cone-beam optical CT system, as well as complementary numerical simulations. A fast GPU implementation of OSC-TV was used to achieve reconstruction times comparable to those of conventional filtered backprojection. Images obtained via OSC-TV were compared with the corresponding filtered backprojections. Spatial resolution and uniformity phantoms were scanned and respective reconstructions were subject to evaluation of the modulation transfer function, image uniformity, and accuracy. The artifacts due to refraction and total signal loss from opaque objects were also studied. The cone-beam optical CT data reconstructions showed that OSC-TV outperforms filtered backprojection in terms of image quality, thanks to a model-based simulation of the photon attenuation process. It was shown to significantly improve the image spatial resolution and reduce image noise. The accuracy of the estimation of linear attenuation coefficients remained similar to that obtained via filtered backprojection. Certain image artifacts due to opaque objects were reduced. Nevertheless, the common artifact due to the gel container walls could not be eliminated. The use of iterative reconstruction improves cone-beam optical CT image quality in many ways. The comparisons between OSC-TV and filtered backprojection presented in this paper demonstrate that OSC-TV can potentially improve the rendering of

  1. Assessing the Organizational Social Context (OSC) of child welfare systems: implications for research and practice.

    Science.gov (United States)

    Glisson, Charles; Green, Philip; Williams, Nathaniel J

    2012-09-01

    The study: (1) provides the first assessment of the a priori measurement model and psychometric properties of the Organizational Social Context (OSC) measurement system in a US nationwide probability sample of child welfare systems; (2) illustrates the use of the OSC in constructing norm-based organizational culture and climate profiles for child welfare systems; and (3) estimates the association of child welfare system-level organizational culture and climate profiles with individual caseworker-level job satisfaction and organizational commitment. The study applies confirmatory factor analysis (CFA) and hierarchical linear models (HLM) analysis to a US nationwide sample of 1,740 caseworkers from 81 child welfare systems participating in the second National Survey of Child and Adolescent Wellbeing (NSCAW II). The participating child welfare systems were selected using a national probability procedure reflecting the number of children served by child welfare systems nationwide. The a priori OSC measurement model is confirmed in this nationwide sample of child welfare systems. In addition, caseworker responses to the OSC scales generate acceptable to high scale reliabilities, moderate to high within-system agreement, and significant between-system differences. Caseworkers in the child welfare systems with the best organizational culture and climate profiles report higher levels of job satisfaction and organizational commitment. Organizational climates characterized by high engagement and functionality, and organizational cultures characterized by low rigidity are associated with the most positive work attitudes. The OSC is the first valid and reliable measure of organizational culture and climate with US national norms for child welfare systems. The OSC provides a useful measure of Organizational Social Context for child welfare service improvement and implementation research efforts which include a focus on child welfare system culture and climate. Copyright © 2012

  2. Modification of an OSCE format to enhance patient continuity in a high-stakes assessment of clinical performance

    Directory of Open Access Journals (Sweden)

    Cuncic Cary

    2011-05-01

    Full Text Available Abstract Background Traditional Objective Structured Clinical Examinations (OSCEs are psychometrically sound but have the limitation of fragmenting complex clinical cases into brief stations. We describe a pilot study of a modified OSCE that attempts to balance a typical OSCE format with a semblance of a continuous, complex, patient case. Methods Two OSCE scenarios were developed. Each scenario involved a single standardized patient and was subdivided into three sequential 10 minute sections that assessed separate content areas and competencies. Twenty Canadian PGY-4 internal medicine trainees were assessed by trained examiner pairs during each OSCE scenario. Paired examiners rated participant performance independent of each other, on each section of each scenario using a validated global rating scale. Inter-rater reliabilities and Pearson correlations between ratings of the 3 sections of each scenario were calculated. A generalizability study was conducted. Participant and examiner satisfaction was surveyed. Results There was no main effect of section or scenario. Inter-rater reliability was acceptable. The g-coefficient was 0.68; four scenarios would achieve 0.80. Moderate correlations between sections of a scenario suggest a possible halo effect. The majority of examiners and participants felt that the modified OSCE provided a sense of patient continuity. Conclusions The modified OSCE provides another approach to the assessment of clinical performance. It attempts to balance the advantages of a traditional OSCE with a sense of patient continuity.

  3. Effect of Clinically Discriminating, Evidence-Based Checklist Items on the Reliability of Scores from an Internal Medicine Residency OSCE

    Science.gov (United States)

    Daniels, Vijay J.; Bordage, Georges; Gierl, Mark J.; Yudkowsky, Rachel

    2014-01-01

    Objective structured clinical examinations (OSCEs) are used worldwide for summative examinations but often lack acceptable reliability. Research has shown that reliability of scores increases if OSCE checklists for medical students include only clinically relevant items. Also, checklists are often missing evidence-based items that high-achieving…

  4. Medical students review of formative OSCE scores, checklists, and videos improves with student-faculty debriefing meetings.

    Science.gov (United States)

    Bernard, Aaron W; Ceccolini, Gabbriel; Feinn, Richard; Rockfeld, Jennifer; Rosenberg, Ilene; Thomas, Listy; Cassese, Todd

    2017-01-01

    Performance feedback is considered essential to clinical skills development. Formative objective structured clinical exams (F-OSCEs) often include immediate feedback by standardized patients. Students can also be provided access to performance metrics including scores, checklists, and video recordings after the F-OSCE to supplement this feedback. How often students choose to review this data and how review impacts future performance has not been documented. We suspect student review of F-OSCE performance data is variable. We hypothesize that students who review this data have better performance on subsequent F-OSCEs compared to those who do not. We also suspect that frequency of data review can be improved with faculty involvement in the form of student-faculty debriefing meetings. Simulation recording software tracks and time stamps student review of performance data. We investigated a cohort of first- and second-year medical students from the 2015-16 academic year. Basic descriptive statistics were used to characterize frequency of data review and a linear mixed-model analysis was used to determine relationships between data review and future F-OSCE performance. Students reviewed scores (64%), checklists (42%), and videos (28%) in decreasing frequency. Frequency of review of all metric and modalities improved when student-faculty debriefing meetings were conducted (p<.001). Among 92 first-year students, checklist review was associated with an improved performance on subsequent F-OSCEs (p = 0.038) by 1.07 percentage points on a scale of 0-100. Among 86 second year students, no review modality was associated with improved performance on subsequent F-OSCEs. Medical students review F-OSCE checklists and video recordings less than 50% of the time when not prompted. Student-faculty debriefing meetings increased student data reviews. First-year student's review of checklists on F-OSCEs was associated with increases in performance on subsequent F-OSCEs, however this

  5. Reacting to Conflict: Civilian Capabilities in the EU, UN and OSCE

    NARCIS (Netherlands)

    Dijkstra, Hylke; Petrov, Petar; Mahr, Ewa

    2016-01-01

    This report analyses how the EU, UN and OSCE make resources available for civilian missions. It starts with an overview of civilian missions around the world before comparing civilian planning and conduct procedures in these international organisations. The report zooms in on EU civilian

  6. A fast 4D cone beam CT reconstruction method based on the OSC-TV algorithm.

    Science.gov (United States)

    Mascolo-Fortin, Julia; Matenine, Dmitri; Archambault, Louis; Després, Philippe

    2018-01-01

    Four-dimensional cone beam computed tomography allows for temporally resolved imaging with useful applications in radiotherapy, but raises particular challenges in terms of image quality and computation time. The purpose of this work is to develop a fast and accurate 4D algorithm by adapting a GPU-accelerated ordered subsets convex algorithm (OSC), combined with the total variation minimization regularization technique (TV). Different initialization schemes were studied to adapt the OSC-TV algorithm to 4D reconstruction: each respiratory phase was initialized either with a 3D reconstruction or a blank image. Reconstruction algorithms were tested on a dynamic numerical phantom and on a clinical dataset. 4D iterations were implemented for a cluster of 8 GPUs. All developed methods allowed for an adequate visualization of the respiratory movement and compared favorably to the McKinnon-Bates and adaptive steepest descent projection onto convex sets algorithms, while the 4D reconstructions initialized from a prior 3D reconstruction led to better overall image quality. The most suitable adaptation of OSC-TV to 4D CBCT was found to be a combination of a prior FDK reconstruction and a 4D OSC-TV reconstruction with a reconstruction time of 4.5 minutes. This relatively short reconstruction time could facilitate a clinical use.

  7. Belarus and Russia in OSCE Ministerial Council focus / Rokas M. Tracevskis

    Index Scriptorium Estoniae

    Tracevskis, Rokas M.

    2011-01-01

    6.-7. detsembril Vilniuses toimunud OSCE Ministrite Nõukogu kohtumisel räägiti inimõiguste probleemidest, meediavabadusest, Afganistanist, Araabia kevadest, Valgevenes toimuvast ja Venemaal toimunud parlamendivalimistest. Kohtumise avas Leedu president Dalia Grybauskaite. 6. detsembril kohtus USA riigisekretär Hillary Clinton president Dalia Grybauskaite ja välisminister Audronius Azubalisega

  8. Use of the OSCE to Evaluate Brief Communication Skills Training for Dental Students

    Science.gov (United States)

    Cannick, Gabrielle F.; Horowitz, Alice M.; Garr, David R.; Reed, Susan G.; Neville, Brad W.; Day, Terry A.; Woolson, Robert F.; Lackland, Daniel T.

    2009-01-01

    Although communications competency is recommended by the American Dental Education Association, only a few (n=5) dental schools report evaluating students’ skills using a competency examination for communication. This study used an objective structured clinical examination (OSCE) to evaluate dental students’ competency in interpersonal and tobacco cessation communication skills. All students were evaluated on their interpersonal communication skills at baseline and at six months post-OSCE by standardized patients and on their tobacco cessation communication skills by two independent raters. First- and second-year dental students (n=104) were randomized to a control or intervention group. One month after the baseline OSCE, students in the intervention group participated in a two-hour training session in which faculty members communicated with a standardized patient during a head and neck examination and counseled the patient about tobacco cessation. There were no statistically significant differences from baseline to post-test between the intervention and control group students as measured by the OSCE. However, among first-year students, both the intervention (n=23) and control (n=21) groups significantly increased in tobacco cessation communication scores. Second-year students in both intervention (n=24) and control (n=28) groups declined in interpersonal communication skills from baseline to post-test. Overall, this one-shot intervention was not successful, and results suggest that a comprehensive communication skills training course may be more beneficial than a single, brief training session for improving dental students’ communication skills. PMID:17761627

  9. A Procedural Skills OSCE: Assessing Technical and Non-Technical Skills of Internal Medicine Residents

    Science.gov (United States)

    Pugh, Debra; Hamstra, Stanley J.; Wood, Timothy J.; Humphrey-Murto, Susan; Touchie, Claire; Yudkowsky, Rachel; Bordage, Georges

    2015-01-01

    Internists are required to perform a number of procedures that require mastery of technical and non-technical skills, however, formal assessment of these skills is often lacking. The purpose of this study was to develop, implement, and gather validity evidence for a procedural skills objective structured clinical examination (PS-OSCE) for internal…

  10. Correlation between MMI performance and OSCE performance – a pilot study

    Directory of Open Access Journals (Sweden)

    Adetokunbo Oluwasanjo

    2015-06-01

    Full Text Available Objective: The multiple mini-interview (MMI has been shown to have a positive correlation with early medical school performance, clerkship evaluations, and national licensing examinations. There is limited data on its predictive validity at the postgraduate level. Methods: Six hundred and nineteen internship candidates were interviewed using the MMI format by the internal medicine residency program of The Reading Health System, between September 2011 and February 2014. Fifty-two interns were recruited. Each intern participated in an objective structured clinical examination (OSCE 3–4 months after the start of the program. The OSCE score of each intern was used as the independent variable to test the relationship with both the MMI interpersonal score and the MMI overall score. Results: There was a moderate positive correlation between the average MMI interpersonal score and the communication score on the OSCE, r=0.384, n=52, p=0.005, and a negligible relationship between the average MMI overall score and the communication score on the OSCE, r=0.175, n=52, p=0.214. Conclusion: The MMI is a useful tool for residency programs to assess interpersonal and communication skills prior to matriculation into residency training. This study provides evidence for its validity in assessing these competencies.

  11. A Comparison of Standard-Setting Procedures for an OSCE in Undergraduate Medical Education.

    Science.gov (United States)

    Kaufman, David M.; Mann, Karen V.; Muijtjens, Arno M. M.; van der Vleuten, Cees P. M.

    2000-01-01

    Compared four standard-setting procedures for an objective structure clinical examination (OSCE) in medical education. Applied Angoff, borderline, relative, and holistic procedures to the data used to establish a cutoff score for a pass/fail decision. The Angoff and borderline procedures gave similar results; however, the relative and holistic…

  12. M-OSCE as a method to measure dental hygiene students' critical thinking: a pilot study.

    Science.gov (United States)

    McComas, Martha J; Wright, Rebecca A; Mann, Nancy K; Cooper, Mary D; Jacks, Mary E

    2013-04-01

    Educators in all academic disciplines have been encouraged to utilize assessment strategies to evaluate students' critical thinking. The purpose of this study was to assess the viability of the modified objective structured clinical examination (m-OSCE) to evaluate critical thinking in dental hygiene education. This evaluation utilized a convenience sample of senior dental hygiene students. Students participated in the m-OSCE in which portions of a patient case were revealed at four stations. The exam consisted of multiple-choice questions intended to measure students' ability to utilize critical thinking skills. Additionally, there was one fill-in-the-blank question and a treatment plan that was completed at the fifth station. The results of this study revealed that the m-OSCE did not reliably measure dental hygiene students' critical thinking. Statistical analysis found no satisfactory reliability within the multiple-choice questions and moderately reliable results within the treatment planning portion of the examination. In addition, the item analysis found gaps in students' abilities to transfer clinical evidence/data to basic biomedical knowledge as demonstrated through the multiple-choice questioning results. This outcome warrants further investigation of the utility of the m-OSCE, with a focus on modifications to the evaluation questions, grading rubric, and patient case.

  13. 77 FR 28638 - OSC Forms And Survey Renewal for FY 2012-Request for Comment

    Science.gov (United States)

    2012-05-15

    ... employees; and (2) the interpretation and enforcement of Hatch Act provisions on political activity in... Possible Prohibited Political Activity (Violation of the Hatch Act)); (4) Office of Special Counsel (OSC... seeking assistance was fully apprised of their rights; (2) determine whether the individual was successful...

  14. Evaluating verbal and non-verbal communication skills, in an ethnogeriatric OSCE.

    Science.gov (United States)

    Collins, Lauren G; Schrimmer, Anne; Diamond, James; Burke, Janice

    2011-05-01

    Communication during medical interviews plays a large role in patient adherence, satisfaction with care, and health outcomes. Both verbal and non-verbal communication (NVC) skills are central to the development of rapport between patients and healthcare professionals. The purpose of this study was to assess the role of non-verbal and verbal communication skills on evaluations by standardized patients during an ethnogeriatric Objective Structured Clinical Examination (OSCE). Interviews from 19 medical students, residents, and fellows in an ethnogeriatric OSCE were analyzed. Each interview was videotaped and evaluated on a 14 item verbal and an 8 item non-verbal communication checklist. The relationship between verbal and non-verbal communication skills on interview evaluations by standardized patients were examined using correlational analyses. Maintaining adequate facial expression (FE), using affirmative gestures (AG), and limiting both unpurposive movements (UM) and hand gestures (HG) had a significant positive effect on perception of interview quality during this OSCE. Non-verbal communication skills played a role in perception of overall interview quality as well as perception of culturally competent communication. Incorporating formative and summative evaluation of both verbal and non-verbal communication skills may be a critical component of curricular innovations in ethnogeriatrics, such as the OSCE. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  15. Calibration of communication skills items in OSCE checklists according to the MAAS-Global.

    Science.gov (United States)

    Setyonugroho, Winny; Kropmans, Thomas; Kennedy, Kieran M; Stewart, Brian; van Dalen, Jan

    2016-01-01

    Communication skills (CS) are commonly assessed using 'communication items' in Objective Structured Clinical Examination (OSCE) station checklists. Our aim is to calibrate the communication component of OSCE station checklists according to the MAAS-Global which is a valid and reliable standard to assess CS in undergraduate medical education. Three raters independently compared 280 checklists from 4 disciplines contributing to the undergraduate year 4 OSCE against the 17 items of the MAAS-Global standard. G-theory was used to analyze the reliability of this calibration procedure. G-Kappa was 0.8. For two raters G-Kappa is 0.72 and it fell to 0.57 for one rater. 46% of the checklist items corresponded to section three of the MAAS-Global (i.e. medical content of the consultation), whilst 12% corresponded to section two (i.e. general CS), and 8.2% to section one (i.e. CS for each separate phase of the consultation). 34% of the items were not considered to be CS. A G-Kappa of 0.8 confirms a reliable and valid procedure for calibrating OSCE CS checklist items using the MAAS-Global. We strongly suggest that such a procedure is more widely employed to arrive at a stable (valid and reliable) judgment of the communication component in existing checklists for medical students' communication behaviours. It is possible to measure the 'true' caliber of CS in OSCE stations. Students' results are thereby comparable between and across stations, students and institutions. A reliable calibration procedure requires only two raters. Copyright © 2015. Published by Elsevier Ireland Ltd.

  16. Generalized Optimal-State-Constraint Extended Kalman Filter (OSC-EKF)

    Science.gov (United States)

    2017-02-01

    algorithms is demonstrated by achieving reasonable consistency and accuracy on a challenging micro aerial vehicle dataset. simultaneous localization...platforms exist,4 and many others have been constructed with low-cost components. Visual-inertial simultaneous localization and mapping (SLAM) and...epipolar constraints. The OSC-EKF used a window size of 10 frames. The SAM problem was constructed using an inverse -depth feature position param

  17. The first OSCE; does students' experience of performing in public affect their results?

    Science.gov (United States)

    Chan, Michael; Bax, Nigel; Woodley, Caroline; Jennings, Michael; Nicolson, Rod; Chan, Philip

    2015-03-26

    Personal qualities have been shown to affect students' exam results. We studied the effect of experience, and level, of public performance in music, drama, dance, sport, and debate at the time of admission to medical school as a predictor of student achievement in their first objective structured clinical examination (OSCE). A single medical school cohort (n = 265) sitting their first clinical exam in 2011 as third year students were studied. Pre-admission statements made at the time of application were coded for their stated achievements in the level of public performance; participation in each activity was scored 0-3, where 0 was no record, 1 = leisure time activity, 2 = activity at school or local level, 3 = activity at district, regional or national level. These scores were correlated to OSCE results by linear regression and t-test. Comparison was made between the highest scoring students in each area, and students scoring zero by t-test. There was a bell shaped distribution in public performance score in this cohort. There was no significant linear regression relationship between OSCE results and overall performance score, or between any subgroups. There was a significant difference between students with high scores in theatre, debate and vocal music areas, grouped together as verbal performance, and students scoring zero in these areas. (p < 0.05, t-test) with an effect size of 0.4. We found modest effects from pre-admission experience of verbal performance on students' scores in the OSCE examination. As these data are taken from students' admission statements, we call into question the received wisdom that such statements are unreliable.

  18. Communication Skills assessed at OSCE are not affected by Participation in the Adolescent Healthy Sexuality Program

    Directory of Open Access Journals (Sweden)

    Deborah Penava

    2002-12-01

    Full Text Available We proposed that first year medical students who voluntarily participated in the Healthy Sexuality adolescent program would perform better than their peers on an adolescent counseling station at the year-end OSCE (Objective Structured Clinical Examination. In addition we compared medical students’ communication skills at the time of the program as assessed by self, peers and participating adolescents. Methods: Nineteen first year medical students voluntarily participated in the ongoing Healthy Sexuality program. Adolescent participants, medical student peer participants and medical students assessed communication components on a 7-point Likert scale at the end of the program. At the year-end OSCE, all first year medical students at the University of Western Ontario were assessed at an adolescent counseling station by a standardized patient (SP and a physician examiner. Statistical analysis examined differences between the two groups. Results: Students who participated in the Healthy Sexuality program did not perform better than their colleagues on the year-end OSCE. A statistically significant correlation between physician examiner and SP evaluations was found (r = 0.62. Adolescent participants communication skills assessments in the Healthy Sexuality Program demonstrated no significant correlation with medical student assessments (self or peer. Conclusions:Voluntary intervention with adolescents did not result in improved communication skills at the structured year-end examination. Further investigation will be directed towards delineating differences between SP and physician examiner assessments.

  19. Using Item Analysis to Assess Objectively the Quality of the Calgary-Cambridge OSCE Checklist

    Directory of Open Access Journals (Sweden)

    Tyrone Donnon

    2011-06-01

    Full Text Available Background:  The purpose of this study was to investigate the use of item analysis to assess objectively the quality of items on the Calgary-Cambridge Communications OSCE checklist. Methods:  A total of 150 first year medical students were provided with extensive teaching on the use of the Calgary-Cambridge Guidelines for interviewing patients and participated in a final year end 20 minute communication OSCE station.  Grouped into either the upper half (50% or lower half (50% communication skills performance groups, discrimination, difficulty and point biserial values were calculated for each checklist item. Results:  The mean score on the 33 item communication checklist was 24.09 (SD = 4.46 and the internal reliability coefficient was ? = 0.77. Although most of the items were found to have moderate (k = 12, 36% or excellent (k = 10, 30% discrimination values, there were 6 (18% identified as ‘fair’ and 3 (9% as ‘poor’. A post-examination review focused on item analysis findings resulted in an increase in checklist reliability (? = 0.80. Conclusions:  Item analysis has been used with MCQ exams extensively. In this study, it was also found to be an objective and practical approach to use in evaluating the quality of a standardized OSCE checklist.

  20. Forging Consensus for Atrocity Prevention: Assessing the Record of the OSCE

    Directory of Open Access Journals (Sweden)

    Matthew Levinger

    2018-03-01

    Full Text Available This essay examines the record of the Organization for Security and Cooperation in Europe (OSCE in fostering norms and collaborative practices for preventing mass atrocities in Eurasia. Comprising fifty-seven participating states “from Vancouver to Vladivostok,” the OSCE is the sole regional security organization spanning all of the members of NATO and the former Warsaw Pact. Its consensus-based approach to advancing “common and comprehensive security” has proved successful in preventing escalation or containing levels of violence in various conflicts in the Baltic states, Ukraine, Southeastern Europe, and the Caucasus. Since the late 1990s, however, rising geopolitical tensions between NATO and the Russian Federation have undermined the effectiveness of the OSCE’s conflict prevention initiatives. In order for the OSCE to play a more robust role in enhancing human security in Eurasia, it will need to find a path toward rebuilding the normative consensus between Russia and its Western participating states.

  1. Standardised clients as assessors in a veterinary communication OSCE: a reliability and validity study.

    Science.gov (United States)

    Artemiou, E; Adams, C L; Hecker, K G; Vallevand, A; Violato, C; Coe, J B

    2014-11-22

    In human medicine, standardised patients (SP) have been shown to reliably and accurately assess learners' communication performance in high-stakes certification Objective Structured Clinical Examinations (OSCE), offering a feasible way to reduce the need for recruitment, time commitment and coordination of faculty assessors. In this study, we evaluated the use of standardised clients (SC) as a viable option for assessing veterinary students' communication performance. We designed a four-station, two-track communication skills OSCE. SC assessors used an adapted nine-item Liverpool Undergraduate Communication Assessment Scale (LUCAS). Faculty used a 21-item checklist derived from the Calgary-Cambridge Guide (CCG) and a five-point global rating scale. Participants were second year veterinary students (n=96). For the four stations, intrastation reliability (α) ranged from 0.63 to 0.82 for the LUCAS, and 0.73 to 0.87 for the CCG. The interstation reliability coefficients were 0.85 for the LUCAS and 0.89 for the CGG. The calculated Generalisability (G) coefficients were 0.62 for the LUCAS and 0.60 for the CGG. Supporting construct validity, SC and faculty assessors showed a significant correlation between the LUCAS and CCG total percent scores (r=0.45, PStudy results support that SC assessors offer a reliable and valid approach for assessing veterinary communication OSCE. British Veterinary Association.

  2. Assessing Communication Skills of Medical Students in Objective Structured Clinical Examinations (OSCE)--A Systematic Review of Rating Scales.

    Science.gov (United States)

    Cömert, Musa; Zill, Jördis Maria; Christalle, Eva; Dirmaier, Jörg; Härter, Martin; Scholl, Isabelle

    2016-01-01

    Teaching and assessment of communication skills have become essential in medical education. The Objective Structured Clinical Examination (OSCE) has been found as an appropriate means to assess communication skills within medical education. Studies have demonstrated the importance of a valid assessment of medical students' communication skills. Yet, the validity of the performance scores depends fundamentally on the quality of the rating scales used in an OSCE. Thus, this systematic review aimed at providing an overview of existing rating scales, describing their underlying definition of communication skills, determining the methodological quality of psychometric studies and the quality of psychometric properties of the identified rating scales. We conducted a systematic review to identify psychometrically tested rating scales, which have been applied in OSCE settings to assess communication skills of medical students. Our search strategy comprised three databases (EMBASE, PsycINFO, and PubMed), reference tracking and consultation of experts. We included studies that reported psychometric properties of communication skills assessment rating scales used in OSCEs by examiners only. The methodological quality of included studies was assessed using the COnsensus based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. The quality of psychometric properties was evaluated using the quality criteria of Terwee and colleagues. Data of twelve studies reporting on eight rating scales on communication skills assessment in OSCEs were included. Five of eight rating scales were explicitly developed based on a specific definition of communication skills. The methodological quality of studies was mainly poor. The psychometric quality of the eight rating scales was mainly intermediate. Our results reveal that future psychometric evaluation studies focusing on improving the methodological quality are needed in order to yield psychometrically

  3. Assessing Communication Skills of Medical Students in Objective Structured Clinical Examinations (OSCE) - A Systematic Review of Rating Scales

    Science.gov (United States)

    Cömert, Musa; Zill, Jördis Maria; Christalle, Eva; Dirmaier, Jörg; Härter, Martin; Scholl, Isabelle

    2016-01-01

    Background Teaching and assessment of communication skills have become essential in medical education. The Objective Structured Clinical Examination (OSCE) has been found as an appropriate means to assess communication skills within medical education. Studies have demonstrated the importance of a valid assessment of medical students’ communication skills. Yet, the validity of the performance scores depends fundamentally on the quality of the rating scales used in an OSCE. Thus, this systematic review aimed at providing an overview of existing rating scales, describing their underlying definition of communication skills, determining the methodological quality of psychometric studies and the quality of psychometric properties of the identified rating scales. Methods We conducted a systematic review to identify psychometrically tested rating scales, which have been applied in OSCE settings to assess communication skills of medical students. Our search strategy comprised three databases (EMBASE, PsycINFO, and PubMed), reference tracking and consultation of experts. We included studies that reported psychometric properties of communication skills assessment rating scales used in OSCEs by examiners only. The methodological quality of included studies was assessed using the COnsensus based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. The quality of psychometric properties was evaluated using the quality criteria of Terwee and colleagues. Results Data of twelve studies reporting on eight rating scales on communication skills assessment in OSCEs were included. Five of eight rating scales were explicitly developed based on a specific definition of communication skills. The methodological quality of studies was mainly poor. The psychometric quality of the eight rating scales was mainly intermediate. Discussion Our results reveal that future psychometric evaluation studies focusing on improving the methodological quality are needed

  4. A comparative study of the metabolic response in rainbow trout and Nile tilapia to changes in dietary macronutrient composition.

    Science.gov (United States)

    Figueiredo-Silva, A Cláudia; Saravanan, Subramanian; Schrama, Johan W; Panserat, Stéphane; Kaushik, Sadasivam; Geurden, Inge

    2013-03-14

    Metabolic mechanisms underlying the divergent response of rainbow trout (Oncorhynchus mykiss) and Nile tilapia (Oreochromis niloticus) to changes in dietary macronutrient composition were assessed. Fish were fed one of four isoenergetic diets having a digestible protein-to-digestible energy (DP:DE) ratio above or below the optimal DP:DE ratio for both species. At each DP:DE ratio, fat was substituted by an isoenergetic amount of digestible starch as the non-protein energy source (NPE). Dietary DP:DE ratio did not affect growth and only slightly lowered protein gains in tilapia. In rainbow trout fed diets with low DP:DE ratios, particularly with starch as the major NPE source, growth and protein utilisation were highly reduced, underlining the importance of NPE source in this species. We also observed species-specific responses of enzymes involved in amino acid catabolism, lipogenesis and gluconeogenesis to dietary factors. Amino acid transdeamination enzyme activities were reduced by a low dietary DP:DE ratio in both species and in tilapia also by the substitution of fat by starch as the NPE source. Such decreased amino acid catabolism at high starch intakes, however, did not lead to improved protein retention. Our data further suggest that a combination of increased lipogenic and decreased gluconeogenic enzyme activities accounts for the better use of carbohydrates and to the improved glycaemia control in tilapia compared with rainbow tront fed starch-enriched diets with low DP:DE ratio.

  5. Using modified information delivery to enhance the traditional pharmacy OSCE program at TMU - a pilot study.

    Science.gov (United States)

    Lin, Che-Wei; Chang, Elizabeth H; Clinciu, Daniel L; Peng, Yun-Ting; Huang, Wen-Chen; Wu, Chien-Chih; Wu, Jen-Chieh; Li, Yu-Chuan

    2018-05-01

    Objective Structured Clinical Examination (OSCE) has been used in many areas of healthcare training over the years. However, it constantly needs to be upgraded and enhanced due to technological and teaching changes. We aim at implementing an integrative OSCE method which employs informatics via the virtual patient within the pharmacy education curriculum at Taipei Medical University to enhance the pharmacy students' competence for using and disseminating information and to also improve critical thinking and clinical reasoning. We propose an integrated pharmacy OSCE which uses standardized patients and virtual patients (DxR Clinician). To evaluate this method, we designed four simulated stations and pilot tested with 19 students in the first year of the Master in Clinical Pharmacy program. Three stations were simulated as the inpatient pharmacy: 1) History and lab data collection; 2) Prescription review; 3) Calling physician to discuss potential prescription problems. The fourth was simulated as the patient ward station to provide patient education. A satisfaction questionnaire was administered at the end of the study. Students rated their ability of 2.84, 2.37, 2.37, and 3.63 of 5 for each of the four stations, with the second and third being the most difficult stations. The method obtained an average rating of 4.32 of 5 for relevance, 4.16 for improving clinical ability, 4.32 for practicality in future healthcare work, and 4.28 for willing to have another similar learning experience. The integration of Virtual Patient in this study reveals that this assessment method is efficient and practical in many aspects. Most importantly, it provides the test taker with a much closer real-life clinical encounter. Although it is in many ways more difficult, it also provides for better "learning from mistakes" opportunities for test-takers. Copyright © 2017. Published by Elsevier B.V.

  6. Production of nuclear ceramic fuel for nuclear power plants at 'Ulba metallurgical plant' OSC

    International Nuclear Information System (INIS)

    Khadeev, V.G.

    2000-01-01

    The paper describes the flow-sheet of production of uranium dioxide powders and nuclear ceramic fuel pellets of them existing at the facility. 'UMP' OSC applies ADU extraction process of UO2 powders production. An indisputable success of the process is the possibility of use of the wide range of raw materials. Uranium hexafluoride, uranium oxides, uranium metal, uranium tetrafluoride, uranyl salts, uranium ore concentrates, all possible types of uranium-containing materials the processing of which by routine methods is difficult (ashes, scraps, etc.) are used as the raw materials. In addition, a reprocessed nuclear fuel can be used for fuel production. The quality of uranium dioxide powder produced does not depend on the type of uranium raw material used. High selectivity of extraction refining makes possible to obtain material with rather low impurities content that meets practically all specifications for uranium dioxide known to us. Ceramic and process features of uranium dioxide powders, namely, specific surface, bulk density, grain size and sinterability make possible to produce nuclear ceramic fuel with specified features. Quality of uranium dioxide powders produced by 'UMP' OSC was highly rated by General Electric company that is one of the leading companies from fuel manufactures in the USA market . It has certified 'UMP' OSC as its supplier. Currently, our company makes great efforts on establishing production of uranium dioxide powders with natural isotopes content for production of fuel for CANDU reactors. Trial lots of such powders are under tests at some companies manufacturing fuel for this type reactors in Canada, USA and Corea

  7. The quality of feedback during formative OSCEs depends on the tutors’ profile

    Directory of Open Access Journals (Sweden)

    Noelle Junod Perron

    2016-11-01

    Full Text Available Abstract Background During their pre-clinical years, medical students are given the opportunity to practice clinical skills with simulated patients. During these formative objective structured clinical encounters (OSCEs, tutors from various backgrounds give feedback on students’ history taking, physical exam, and communication skills. The aim of the study was to evaluate whether the content and process of feedback varied according to the tutors’ profile. Methods During 2013, all 2nd and 3rd year medical students and tutors involved in three formative OSCEs were asked to fill in questionnaires, and their feedback sessions were audiotaped. Tutors were divided into two groups: 1 generalists: primary care, general internist and educationalist physicians 2 specialists involved in the OSCE related to their field of expertise. Outcome measures included the students’ perceptions of feedback quality and utility and objective assessment of feedback quality. Results Participants included 251 medical students and 38 tutors (22 generalists and 16 specialists. Students self-reported that feedback was useful to improve history taking, physical exam and communication skills. Objective assessment showed that feedback content essentially focused on history taking and physical exam skills, and that elaboration on clinical reasoning or communication/professionalism issues was uncommon. Multivariate analyses showed that generalist tutors used more learner-centered feedback skills than specialist tutors (stimulating student’s self-assessment (p < .001; making the student active in finding solutions, p < .001; checking student’s understanding, p < .001 and elaborated more on communication and professionalism issues (p < 0.001. Specialists reported less training in how to provide feedback than generalists. Conclusion These findings suggest that generalist tutors are more learner-centered and pay more attention to communication and

  8. Understanding the application of OSC policy 9.1 during a takeover transaction

    International Nuclear Information System (INIS)

    Hayduk, M.F.; Rasmuson, M.A.

    1998-01-01

    Legal aspects of ownership of publicly traded companies in Canada are explored, with particular emphasis on transactions involving 'related parties'. In this context, Policy 9.1 of the Ontario Securities Commission is examined. The policy seeks to enhance minority shareholder protection by providing for independent valuation, majority of minority approval, enhanced disclosure and review of substantial transactions by independent directors. This paper focuses on four types of transactions governed by Policy 9.1, i.e. insider bids, issuer bids, going private transactions, related party transactions and the recent proposed rule reformulation proposed by the Ontario Securities Commission (OSC)

  9. Las Organizaciones de la Sociedad Civil (OSC) y la agenda internacional del desarrollo: escenario latinoamericano

    OpenAIRE

    Revilla Blanco, María Luisa

    2012-01-01

    En este artículo se analiza la acción de las organizaciones de la sociedad civil latinoamericanas: su evolución y el papel que juegan en la definición de la agenda internacional del desarrollo desde América Latina. Para ello, me detendré en los siguientes puntos: 1. Los hitos más importantes en la generación de consensos sobre los contenidos de esa agenda de desarrollo en lo que va de siglo y el reconocimiento del papel de las OSC. 2. La situación de América Latina en este contexto. ...

  10. Improved OSC Amtec generator design to meet goals of JPL's candidate Europa Orbiter mission

    International Nuclear Information System (INIS)

    Schock, A.; Noravian, H.; Or, C.; Kumar, V.

    1998-01-01

    The preceding paper (Paper IECEC.98.244) described OSC's initial designs of AMTEC (Alkali Metal Thermal-to-Electrical Conversion) power systems, consisting of one or two generators, each with 2, 3, or 4 General Purpose Heat Source (GPHS) modules and with 16 refractory AMTEC cells containing 5 Beta Alumina Solid Electrolyte (BASE) tubes; and presented the effect of heat input and voltage output on the generator's BOM evaporator and clad temperatures and on its EOM system efficiency and power output. Comparison of the computed results with JPL's goals for the Europa Orbiter mission showed that all of the initial 16-cell design options yielded either excessive evaporator and clad temperatures or insufficient EOM power to satisfy the JPL-specified mission goals. The present paper describes modified OSC generator designs with different numbers of AMTEC cells, cell diameters, cell lengths, cell materials, BASE tube lengths, and number of tubes per cell. These efforts succeeded in identifying generator designs with only half the number of AMTEC cells which -- for the same assumptions -- can produce EOM power outputs substantially in excess of JPL's goals for NASA's Europa Orbiter mission while operating well below the prescribed BOM limits on evaporator and clad temperature; and revealed that lowering the emissivity of the generator's housing to raise the cells' condenser temperatures can achieve substantial additional performance improvement. Finally, the paper culminates in programmatic recommendations

  11. How well do second-year students learn physical diagnosis? Observational study of an objective structured clinical examination (OSCE

    Directory of Open Access Journals (Sweden)

    Simon Steven R

    2002-01-01

    Full Text Available Abstract Background Little is known about using the Objective Structured Clinical Examination (OSCE in physical diagnosis courses. The purpose of this study was to describe student performance on an OSCE in a physical diagnosis course. Methods Cross-sectional study at Harvard Medical School, 1997–1999, for 489 second-year students. Results Average total OSCE score was 57% (range 39–75%. Among clinical skills, students scored highest on patient interaction (72%, followed by examination technique (65%, abnormality identification (62%, history-taking (60%, patient presentation (60%, physical examination knowledge (47%, and differential diagnosis (40% (p Conclusions Students scored higher on interpersonal and technical skills than on interpretive or integrative skills. Station scores identified specific content that needs improved teaching.

  12. Development and testing of an objective structured clinical exam (OSCE) to assess socio-cultural dimensions of patient safety competency

    Science.gov (United States)

    Ginsburg, Liane R; Tregunno, Deborah; Norton, Peter G; Smee, Sydney; de Vries, Ingrid; Sebok, Stefanie S; VanDenKerkhof, Elizabeth G; Luctkar-Flude, Marian; Medves, Jennifer

    2015-01-01

    Background Patient safety (PS) receives limited attention in health professional curricula. We developed and pilot tested four Objective Structured Clinical Examination (OSCE) stations intended to reflect socio-cultural dimensions in the Canadian Patient Safety Institute's Safety Competency Framework. Setting and participants 18 third year undergraduate medical and nursing students at a Canadian University. Methods OSCE cases were developed by faculty with clinical and PS expertise with assistance from expert facilitators from the Medical Council of Canada. Stations reflect domains in the Safety Competency Framework (ie, managing safety risks, culture of safety, communication). Stations were assessed by two clinical faculty members. Inter-rater reliability was examined using weighted κ values. Additional aspects of reliability and OSCE performance are reported. Results Assessors exhibited excellent agreement (weighted κ scores ranged from 0.74 to 0.82 for the four OSCE stations). Learners’ scores varied across the four stations. Nursing students scored significantly lower (p<0.05) than medical students on three stations (nursing student mean scores=1.9, 1.9 and 2.7; medical student mean scores=2.8, 2.9 and 3.5 for stations 1, 2 and 3, respectively where 1=borderline unsatisfactory, 2=borderline satisfactory and 3=competence demonstrated). 7/18 students (39%) scored below ‘borderline satisfactory’ on one or more stations. Conclusions Results show (1) four OSCE stations evaluating socio-cultural dimensions of PS achieved variation in scores and (2) performance on this OSCE can be evaluated with high reliability, suggesting a single assessor per station would be sufficient. Differences between nursing and medical student performance are interesting; however, it is unclear what factors explain these differences. PMID:25398630

  13. GPU-accelerated few-view CT reconstruction using the OSC and TV techniques

    Energy Technology Data Exchange (ETDEWEB)

    Matenine, Dmitri [Montreal Univ., QC (Canada). Dept. de Physique; Hissoiny, Sami [Ecole Polytechnique de Montreal, QC (Canada). Dept. de Genie Informatique et Genie Logiciel; Despres, Philippe [Centre Hospitalier Univ. de Quebec, QC (Canada). Dept. de Radio-Oncologie

    2011-07-01

    The present work proposes a promising iterative reconstruction technique designed specifically for X-ray transmission computed tomography (CT). The main objective is to reduce diagnostic radiation dose through the reduction of the number of CT projections, while preserving image quality. The second objective is to provide a fast implementation compatible with clinical activities. The proposed tomographic reconstruction technique is a combination of the Ordered Subsets Convex (OSC) algorithm and the Total Variation minimization (TV) regularization technique. The results in terms of image quality and computational speed are discussed. Using this technique, it was possible to obtain reconstructed slices of relatively good quality with as few as 100 projections, leading to potential dose reduction factors of up to an order of magnitude depending on the application. The algorithm was implemented on a Graphical Processing Unit (GPU) and yielded reconstruction times of approximately 185 ms per slice. (orig.)

  14. Is the OSCE more stressful? Examination anxiety and its consequences in different assessment methods in dental education

    NARCIS (Netherlands)

    Brand, H.S.; Schoonheim-Klein, M.

    2009-01-01

    Objective: To measure the levels of anxiety, self-perception of preparation and expectation for success induced by an objective structured clinical examination (OSCE), a written examination and a preclinical preparation test, and to examine the effects of the three predictive variables on the

  15. Exploration of Nursing Faculty Members' Lived Experiences of Objective Structured Clinical Examination (OSCE) in Undergraduate Nursing Education

    Science.gov (United States)

    Obizoba, Cordelia O.

    2014-01-01

    The purpose of this phenomenological study was to gain an understanding of nursing faculty members' lived experiences of Objective Structured Clinical Examination (OSCE) in undergraduate nursing education. As owners of their programs' curriculum, nursing faculties are charged with the responsibility of providing needed knowledge, skills, and…

  16. The use of global rating scales for OSCEs in veterinary medicine.

    Directory of Open Access Journals (Sweden)

    Emma K Read

    Full Text Available OSCEs (Objective Structured Clinical Examinations are widely used in health professions to assess clinical skills competence. Raters use standardized binary checklists (CL or multi-dimensional global rating scales (GRS to score candidates performing specific tasks. This study assessed the reliability of CL and GRS scores in the assessment of veterinary students, and is the first study to demonstrate the reliability of GRS within veterinary medical education. Twelve raters from two different schools (6 from University of Calgary [UCVM] and 6 from Royal (Dick School of Veterinary Studies [R(DSVS] were asked to score 12 students (6 from each school. All raters assessed all students (video recordings during 4 OSCE stations (bovine haltering, gowning and gloving, equine bandaging and skin suturing. Raters scored students using a CL, followed by the GRS. Novice raters (6 R(DSVS were assessed independently of expert raters (6 UCVM. Generalizability theory (G theory, analysis of variance (ANOVA and t-tests were used to determine the reliability of rater scores, assess any between school differences (by student, by rater, and determine if there were differences between CL and GRS scores. There was no significant difference in rater performance with use of the CL or the GRS. Scores from the CL were significantly higher than scores from the GRS. The reliability of checklist scores were .42 and .76 for novice and expert raters respectively. The reliability of the global rating scale scores were .7 and .86 for novice and expert raters respectively. A decision study (D-study showed that once trained using CL, GRS could be utilized to reliably score clinical skills in veterinary medicine with both novice and experienced raters.

  17. Performance of OSC's initial Amtec generator design, and comparison with JPL's Europa Orbiter goals

    International Nuclear Information System (INIS)

    Schock, A.; Noravian, H.; Or, C.; Kumar, V.

    1998-01-01

    The procedure for the analysis (with overpotential correction) of multitube AMTEC (Alkali Metal Thermal-to-Electrical Conversion) cells described in Paper IECEC 98-243 was applied to a wide range of multicell radioisotope space power systems. System design options consisting of one or two generators, each with 2, 3, or 4 stacked GPHS (General Purpose Heat Source) modules, identical to those used on previous NASA missions, were analyzed and performance-mapped. The initial generators analyzed by OSC had 8 AMTEC cells on each end of the heat source stack, with five beta-alumina solid electrolyte (BASE) tubes per cell. The heat source and converters in the Orbital generator designs are embedded in a thermal insulation system consisting of Min-K fibrous insulation surrounded by graded-length molybdenum multifoils. Detailed analyses in previous Orbital studies found that such an insulation system could reduce extraneous heat losses to about 10%. For the above design options, the present paper presents the system mass and performance (i.e., the EOM system efficiency and power output and the BOM evaporator and clad temperatures) for a wide range of heat inputs and load voltages, and compares the results with JPL's preliminary goals for the Europa Orbiter mission to be launched in November 2003. The analytical results showed that the initial 16-cell generator designs resulted in either excessive evaporator and clad temperatures and/or insufficient power outputs to meet the JPL-specified mission goals. The computed performance of modified OSC generators with different numbers of AMTEC cells, cell diameters, cell lengths, cell materials, BASE tube lengths, and number of tubes per cell are described in Paper IECEC.98.245 in these proceedings

  18. Assessing nursing clinical skills competence through objective structured clinical examination (OSCE) for open distance learning students in Open University Malaysia.

    Science.gov (United States)

    Oranye, Nelson Ositadimma; Ahmad, Che'an; Ahmad, Nora; Bakar, Rosnida Abu

    2012-06-01

    The objective structured clinical skills examination (OSCE) has over the years emerged as a method of evaluating clinical skills in most medical and allied professions. Although its validity and objectivity has evoked so much debate in the literature, little has been written about its application in non-traditional education systems such as in distance learning. This study examined clinical skills competence among practising nursing students who were enrolled in a distance learning programme. The study examined the effect of work and years of nursing practice on nurses' clinical skills competence. This study used observational design whereby nursing students' clinical skills were observed and scored in five OSCE stations. Two instruments were used for the data collection - A self-administered questionnaire on the students' bio-demographic data, and a check list on the clinical skills which the examiners rated on a four point scale. The findings revealed that 14% of the nurses had level four competence, which indicated that they could perform the tasks correctly and complete. However, 12% failed the OSCE, even though they had more than 10 years experience in nursing and post basic qualifications. Inter-rater reliability was 0.92 for the five examiners. Factor analysis indicated that five participant factors accounted for 74.1% of the variations in clinical skills performance. An OSCE is a necessary assessment tool that should be continuously applied in nursing education, regardless of the mode of the education program, the student's years of experience or his/her clinical placement. This study validates the need for OSCE in both the design of tertiary nursing degree programs and the assessment of nurses' clinical competency level.

  19. Development, implementation, and evaluation of an integrated multidisciplinary Objective Structured Clinical Examination (OSCE) in primary health care settings within limited resources.

    Science.gov (United States)

    Abdelaziz, Adel; Hany, Mohamed; Atwa, Hani; Talaat, Wagdy; Hosny, Somaya

    2016-01-01

    In ordinary circumstances, objective structured clinical examination (OSCE) is a resource-intensive assessment method. In case of developing and implementing multidisciplinary OSCE, there is no doubt that the cost will be greater. Through this study a research project was conducted to develop, implement and evaluate a multidisciplinary OSCE model within limited resources. This research project went through the steps of blueprinting, station writing, resources reallocation, implementation and finally evaluation. The developed model was implemented in the Primary Health Care (PHC) program which is one of the pillars of the Community-Based undergraduate curriculum of the Faculty of Medicine, Suez Canal University (FOM-SCU). Data for evaluation of the implemented OSCE model were derived from two resources. First, feedback of the students and assessors through self-administered questionnaires was obtained. Second, evaluation of the OSCE psychometrics was done. The deliverables of this research project included a set of validated integrated multi-disciplinary and low cost OSCE stations with an estimated reliability index of 0.6. After having this experience, we have a critical mass of faculty members trained on blueprinting and station writing and a group of trained assessors, facilitators and role players. Also there is a state of awareness among students on how to proceed in this type of OSCE which renders future implementation more feasible.

  20. Team OSCE: A Teaching Modality for Promotion of Multidisciplinary Work in Mental Health Settings.

    Science.gov (United States)

    Sharma, Manoj Kumar; Chandra, Prabha S; Chaturvedi, Santosh K

    2015-01-01

    The objective structured clinical examination has been in use both as an assessment and a teaching modality within the mental health profession. It focuses on individual skill enhancement, the inter-professional understanding of role obligation is helpful in promoting competence as a team as well as role of other team members. The Team OSCE (TOSCE) is an effective way in promoting inter-professional learning. The present work assesses the trainee experience with TOSCE and its utility in clinical care. Twenty-two mental health trainees (17 male and 5 female from psychiatry, clinical psychology and psychiatric social work) got exposure to weekly OSCAF training as well as 2-3 Team OSCAFS on various aspects of clinical work as a part of their clinical training for 3 months. Rating from the trainees were taken on TOSCE feedback checklist. TOSCE was helpful in promoting the understanding role of other team members; shared decision-making, problem-solving, handling unexpected events, giving feedback and closure. The TOSCE may be introduced as a way to work on clinical performance, shared decision-making and inter-professional understanding.

  1. An innovative OSCE clinical log station: a quantitative study of its influence on Log use by medical students

    Directory of Open Access Journals (Sweden)

    Hudson Judith N

    2012-11-01

    Full Text Available Abstract Background A Clinical Log was introduced as part of a medical student learning portfolio, aiming to develop a habit of critical reflection while learning was taking place, and provide feedback to students and the institution on learning progress. It was designed as a longitudinal self-directed structured record of student learning events, with reflection on these for personal and professional development, and actions planned or taken for learning. As incentive was needed to encourage student engagement, an innovative Clinical Log station was introduced in the OSCE, an assessment format with established acceptance at the School. This study questions: How does an OSCE Clinical Log station influence Log use by students? Methods The Log station was introduced into the formative, and subsequent summative, OSCEs with careful attention to student and assessor training, marking rubrics and the standard setting procedure. The scoring process sought evidence of educational use of the log, and an ability to present and reflect on key learning issues in a concise and coherent manner. Results Analysis of the first cohort’s Log use over the four-year course (quantified as number of patient visits entered by all students revealed limited initial use. Usage was stimulated after introduction of the Log station early in third year, with some improvement during the subsequent year-long integrated community-based clerkship. Student reflection, quantified by the mean number of characters in the ‘reflection’ fields per entry, peaked just prior to the final OSCE (mid-Year 4. Following this, very few students continued to enter and reflect on clinical experience using the Log. Conclusion While the current study suggested that we can’t assume students will self-reflect unless such an activity is included in an assessment, ongoing work has focused on building learner and faculty confidence in the value of self-reflection as part of being a competent

  2. Student´s self-assessment of clinical competence and objective clinical performance in OSCE evaluation

    OpenAIRE

    Jünger, J; Schellberg, D; Nikendei, C

    2006-01-01

    [english] Overestimating one's clinical competence can be dangerous to patient's safety. Therefore the goal of this study was to identify students with high confidence in their own clinical competence but low performance in objective assessment. 171 students in the 14 week course in internal medicine completed the clinical skills-related self-assessment expectations (SE) and were tested in a 12 station OSCE. Both measures were obtained within three days. In total we identified 16% of students...

  3. Objective Structured Clinical Examinations (OSCEs, psychiatry and the Clinical assessment of Skills and Competencies (CASCSame Evidence, Different Judgement

    Directory of Open Access Journals (Sweden)

    Marwaha Steven

    2011-05-01

    Full Text Available Abstract Background The Objective Structured Clinical Examination (OSCE, originally developed in the 1970's, has been hailed as the "gold standard" of clinical assessments for medical students and is used within medical schools throughout the world. The Clinical assessment of Skills and Competencies (CASC is an OSCE used as a clinical examination gateway, granting access to becoming a senior Psychiatrist in the UK. Discussion Van der Vleuten's utility model is used to examine the CASC from the viewpoint of a senior psychiatrist. Reliability may be equivalent to more traditional examinations. Whilst the CASC is likely to have content validity, other forms of validity are untested and authenticity is poor. Educational impact has the potential to change facets of psychiatric professionalism and influence future patient care. There are doubts about acceptability from candidates and more senior psychiatrists. Summary Whilst OSCEs may be the best choice for medical student examinations, their use in post graduate psychiatric examination in the UK is subject to challenge on the grounds of validity, authenticity and educational impact.

  4. Testing clinical competencies in undergraduate nursing education using Objective Structured Clinical Examination (OSCE) – a literature review of international practice

    Science.gov (United States)

    Beyer, Angelika; Dreier, Adina; Kirschner, Stefanie; Hoffmann, Wolfgang

    2016-07-01

    Background: In response to demographic trends in Germany nursing competencies are currently reevaluated. Since these have to be taught and trained in nursing education programs, efficient verification of the success is necessary. OSCEs are internationally well-recognized as a comprehensive tool for that. Aim: In this analysis we identified competencies worldwide, which are tested by OSCEs in undergraduate nursing education programs. Method: An international literature research was conducted. The selection criterion for an article was the specification of at least one verifiable competency. Afterwards the competencies were categorized into knowledge, skills and attitudes according to the German “Fachqualifikationsrahmen Pflege für die hochschulische Bildung”. Results: A total of 36 publications fulfilled all inclusion criteria. Relevant studies were predominantly initiated in the UK, Canada and Australia. Within all categories a total of n = 166 different competencies are mentioned. OSCEs are developed and performed in a broad range of methods. Most frequently skills were verified. The most common topic was sure handling of medication. Other important themes were communicative competencies in relation to patients and the ability of self-evaluation. Discussion/Conclusions: A variation in examination methods is appropriate as different competencies are acquired in preparation of the test. Evaluation took place on an individual or institutional level. Further research is needed.

  5. Composites

    International Nuclear Information System (INIS)

    Kasen, M.B.

    1983-01-01

    This chapter discusses the roles of composite laminates and aggregates in cryogenic technology. Filamentary-reinforced composites are emphasized because they are the most widely used composite materials. Topics considered include composite systems and terminology, design and fabrication, composite failure, high-pressure reinforced plastic laminates, low-pressure reinforced plastics, reinforced metals, selectively reinforced structures, the effect of cryogenic temperatures, woven-fabric and random-mat composites, uniaxial fiber-reinforced composites, composite joints in cryogenic structures, joining techniques at room temperature, radiation effects, testing laminates at cryogenic temperatures, static and cyclic tensile testing, static and cyclic compression testing, interlaminar shear testing, secondary property tests, and concrete aggregates. It is suggested that cryogenic composite technology would benefit from the development of a fracture mechanics model for predicting the fitness-for-purpose of polymer-matrix composite structures

  6. Modifying the organic/electrode interface in Organic Solar Cells (OSCs) and improving the efficiency of solution-processed phosphorescent Organic Light-Emitting Diodes (OLEDs)

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Teng [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    Organic semiconductors devices, such as, organic solar cells (OSCs), organic light-emitting diodes (OLEDs) and organic field-effect transistors (OFETs) have drawn increasing interest in recent decades. As organic materials are flexible, light weight, and potentially low-cost, organic semiconductor devices are considered to be an alternative to their inorganic counterparts. This dissertation will focus mainly on OSCs and OLEDs. As a clean and renewable energy source, the development of OSCs is very promising. Cells with 9.2% power conversion efficiency (PCE) were reported this year, compared to < 8% two years ago. OSCs belong to the so-called third generation solar cells and are still under development. While OLEDs are a more mature and better studied field, with commercial products already launched in the market, there are still several key issues: (1) the cost of OSCs/OLEDs is still high, largely due to the costly manufacturing processes; (2) the efficiency of OSCs/OLEDs needs to be improved; (3) the lifetime of OSCs/OLEDs is not sufficient compared to their inorganic counterparts; (4) the physics models of the behavior of the devices are not satisfactory. All these limitations invoke the demand for new organic materials, improved device architectures, low-cost fabrication methods, and better understanding of device physics. For OSCs, we attempted to improve the PCE by modifying the interlayer between active layer/metal. We found that ethylene glycol (EG) treated poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT: PSS) improves hole collection at the metal/polymer interface, furthermore it also affects the growth of the poly(3- hexylthiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM) blends, making the phase segregation more favorable for charge collection. We then studied organic/inorganic tandem cells. We also investigated the effect of a thin LiF layer on the hole-collection of copper phthalocyanine (CuPc)/C70-based small molecular OSCs. A

  7. Subjektive Kompetenzeinschätzung von Studierenden und ihre Leistung im OSCE [Student´s self-assessment of clinical competence and objective clinical performance in OSCE evaluation

    Directory of Open Access Journals (Sweden)

    Jünger, Jana

    2006-08-01

    Full Text Available [english] Overestimating one's clinical competence can be dangerous to patient's safety. Therefore the goal of this study was to identify students with high confidence in their own clinical competence but low performance in objective assessment. 171 students in the 14 week course in internal medicine completed the clinical skills-related self-assessment expectations (SE and were tested in a 12 station OSCE. Both measures were obtained within three days. In total we identified 16% of students who overestimated their performance in clinical skills compared to their OSCE-results. Male students significantly more oversestimated their clinical compltence (31% than female students. One possible cause may be the lack of corrective experiences during clinical traineeship leading to the misconception of own performance. Further validation and the integration of a counselling program for these students seem necessary. [german] Die Selbstüberschätzung ärztlicher Kompetenzen kann weitereichende Konsequenzen für die Patientensicherheit haben. Aus diesem Grunde initiierten wir eine Studie zur Identifizierung von Studierenden, die ihre klinische Kompetenz als sehr gut einschätzen, jedoch eine unzufriedenstellende objektive klinisch-praktische Performanz aufweisen. 171 Studierende des 14-wöchigen Blockes Innere Medizin an der Medizinischen Universitätsklinik Heidelberg füllten einen Selbsteinschätzungsfragebogen zur klinischen Kompetenz aus und wurden in einem 12-Stationen OSCE evaluiert. Beide Messungen wurden innerhalb von drei Tagen vollzogen. Insgesamt konnten 16% der Studierenden identifiziert werden, die sich verglichen mit den OSCE-Ergebnissen, bezüglich ihrer klinisch-praktischen Fertigkeit selbst überschätzen. Dabei überschätzen sich signifikant mehr männliche (31% als weibliche (8% Studierende. Eine mögliche Erklärung für den Sachverhalt der studentischen Fehleinschätzung klinischer Kompetenzen könnte in fehlenden korrigierenden R

  8. Evaluation of a multi-methods approach to the collection and dissemination of feedback on OSCE performance in dental education.

    Science.gov (United States)

    Wardman, M J; Yorke, V C; Hallam, J L

    2018-05-01

    Feedback is an essential part of the learning process, and students expect their feedback to be personalised, meaningful and timely. Objective Structured Clinical Examination (OSCE) assessments allow examiners to observe students carefully over the course of a number of varied station types, across a number of clinical knowledge and skill domains. They therefore present an ideal opportunity to record detailed feedback which allows students to reflect on and improve their performance. This article outlines two methods by which OSCE feedback was collected and then disseminated to undergraduate dental students across 2-year groups in a UK dental school: (i) Individual written feedback comments made by examiners during the examination, (ii) General audio feedback recorded by groups of examiners immediately following the examination. Evaluation of the feedback was sought from students and staff examiners. A multi-methods approach utilising Likert questionnaire items (quantitative) and open-ended feedback questions (qualitative) was used. Data analysis explored student and staff perceptions of the audio and written feedback. A total of 131 students (response rate 68%) and 52 staff examiners (response rate 83%) completed questionnaires. Quantitative data analysis showed that the written and audio formats were reported as a meaningful source of feedback for learning by both students (93% written, 89% audio) and staff (96% written, 92% audio). Qualitative data revealed the complementary nature of both types of feedback. Written feedback gives specific, individual information whilst audio shares general observations and allows students to learn from others. The advantages, limitations and challenges of the feedback methods are discussed, leading to the development of an informed set of implementation guidelines. Written and audio feedback methods are valued by students and staff. It is proposed that these may be very easily applied to OSCEs running in other dental schools.

  9. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2011-01-01

    Strategies are open compositions to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them in full...

  10. Composition

    DEFF Research Database (Denmark)

    2014-01-01

    Memory Pieces are open compositions to be realised solo by an improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them...

  11. The Objective Structured Clinical Examination (OSCE) as a strategy for assessing clinical competence in midwifery education in Ireland: a critical review.

    Science.gov (United States)

    Smith, Valerie; Muldoon, Kathryn; Biesty, Linda

    2012-09-01

    In Ireland, to register as a midwife, all student midwives must be deemed competent to practice with the assessment of competence an essential component of midwifery education. A variety of assessment strategies, including observed practice, clinical interviews, portfolios of reflection, the Objective Structured Clinical Examination (OSCE) and written examination papers, are utilised to assess midwifery students' clinical competence. In this paper, a critical review of the OSCE as a strategy for assessing clinical competence in one third level institution in Ireland is offered. Although utilised for assessing competence across a range of areas (e.g. obstetric emergencies and pharmacology/drug administration), the use of the OSCE for assessing midwifery students' competence in lactation and infant feeding practices, as an example for this paper, is described. The advantages, disadvantages, validity and reliability of the OSCE, as an assessment strategy, are critically explored. Recognising that no single assessment strategy can provide all the information required to assess something as complex as clinical performance, the OSCE, when viewed alongside other forms of assessment, and with relevance to the topic under examination, may be considered a valuable strategy for enhancing the assessment of students' clinical competence, and for embracing diversity within midwifery education and training. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Wahlfach Teamarbeit: Ergebnisse eines Pilotprojektes zur interprofessionellen und interdisziplinären Ausbildung mit formativem Team-OSCE (TOSCE [Teamwork elective: Results of a German pilot project on interprofessional and interdisciplinary education with formative team OSCE

    Directory of Open Access Journals (Sweden)

    Schmidt, Anita

    2010-08-01

    Full Text Available [english] Aims: There is a growing need to implement teamworking in medical education. In reality, interdisciplinary and interprofessional education is often absent. Here we describe a pilot trial developed jointly by the nursing college and the medical faculty in Erlangen (Germany in which nursing students and undergraduate medical students formed interprofessional teams and were confronted with interprofessional cases using simulated patients (SPs and phantoms. The elective was planned using standard curriculum planning instruments and finally evaluated with a novel formative team OSCE (Objective Structured Clinical Evaluation instrument.Methods: During one year, 20 nursing students participated voluntarily in the project and 10 medical students took the course as an elective. Results: The pilot project was first performed with two tutors, one from the medical school and one from the nursing school, as well as one to two SPs. During the second course, there was only one tutor. Overall evaluation of the voluntary students was good, with some elements (acute stroke, factual knowledge, and general organizational problems that needed to be improved. Performance of a four-station team OSCE was feasible, but raters reported problems in assessing individuals and the team at the same time. Interobserver agreement was satisfactory (kappa 0.35.Conclusions: Interdisciplinary and interprofessional education between a nursing school and a medical school is feasible within an elective, but requires substantial personnel resources. Design and performance of a team OSCE is possible. The validity of the test has to be shown on follow-up.[german] Zielsetzung: Das Lernziel „Fähigkeit zur interprofessionellen und interdisziplinären Teamarbeit“ wird sowohl in der aktuellen Approbationsordnung für Ärzte als auch im Krankenpflegegesetz gefordert. In der Realität gibt es in beiden Ausbildungen kaum gemeinsame Lehreinheiten. Wir beschreiben ein Pilotprojekt

  13. Feedback promotes learning success! Which kind of feedback for the faculty is given by an interdisciplinary OSCE with focus on decision-making?

    Directory of Open Access Journals (Sweden)

    Stibane, Tina

    2016-08-01

    Full Text Available Clinical skills such as history taking, diagnostic reasoning, therapy planning, and giving advice are even more complex than practical skills like lung auscultation and have to be applied in complex clinical situations. We judged this competence in an interdisciplinary formative OSCE conducted with students of Marburg University. Results of 218 students passing 643 OSCE stations composed of 37 different scenarios were analyzed. As a competence based examination that reflects the practical skills gained during clinical training, the here presented analysis serves also as a feedback instrument for clinical teachers, their respective disciplines and the medical faculty as a whole.

  14. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2014-01-01

    Cue Rondo is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound/video files will in some cases only provide a few minutes' sample, or the visuals will not appear at all....... Please DOWNLOAD them to see/hear them in full length! This work is licensed under a Creative Commons "by-nc" License. You may for non-commercial purposes use and distribute it, performance instructions as well as specially designated recordings, as long as the author is mentioned. Please see http...

  15. Assessing third-year medical students' ability to address a patient's spiritual distress using an OSCE case.

    Science.gov (United States)

    McEvoy, Mimi; Schlair, Sheira; Sidlo, Zsuzsanna; Burton, William; Milan, Felise

    2014-01-01

    To inform curricular development by assessing the ability of third-year medical students to address a patient's spiritual distress during an acute medical crisis in the context of an objective structured clinical examination (OSCE) case. During March and April 2010, 170 third-year medical students completed an eight-station videotaped OSCE at Albert Einstein College of Medicine of Yeshiva University. One of the standardized patients (SPs) was a 65-year-old man with acute chest pain who mentioned his religious affiliation and fear of dying. If prompted, he revealed his desire to speak with a chaplain. The SP assessed students' history taking, physical examination, and communication skills. In a postencounter written exercise, students reported their responses to the patient's distress via four open-ended questions. Analysis of the postencounter notes was conducted by three coders for emergent themes. Clinical skills performance was compared between students who reported making chaplain referral and those who did not. A total of 108 students (64%) reported making a chaplain referral; 4 (2%) directly addressed the patient's religious/spiritual beliefs. Students' clinical performance scores showed no significant association with whether they made a chaplain referral. Findings suggest that the majority of medical students without robust training in addressing patients' spiritual needs can make a chaplain referral when faced with a patient in spiritual crisis. Yet, few students explicitly engaged the patient in a discussion of his beliefs. Thus, future studies are needed to develop more precise assessment measures that can inform development in spirituality and medicine curricula.

  16. 'Hello, my name is Gabriel, I am the house officer, may I examine you?' or the Objective Santa Christmas Examination (OSCE).

    Science.gov (United States)

    Wood, D; Roberts, T; Bradley, P; Lloyd, D; O'Neill, P

    1999-12-01

    To design a clinical examination of high content validity suitable for use as a formative assessment tool with pre-registration house officers (PRHO'S) towards the end of their first house officer post. A multicentre collaboration between four UK medical schools who offer undergraduate curricula which are problem-based, systems-based, patient-orientated, student-centred, jargon-laden and utterly staff-bewildering. An objective structured clinical examination (OSCE) which is suitable for use with graduates of UK medical schools. It assesses the knowledge, skills and attitudes essential for future careers in a hierarchical system where protecting the senior staff from all forms of irritation is paramount. PRHO'S who excel in this examination get better references. The OSCE format can be used to provide 'real-life' scenarios appropriate to the season.

  17. [Implementation of bedside training and advanced objective structured clinical examination (OSCE) trial to learn and confirm about pharmacy clinical skills].

    Science.gov (United States)

    Tokunaga, Jin; Takamura, Norito; Ogata, Kenji; Setoguchi, Nao; Sato, Keizo

    2013-01-01

    Bedside training for fourth-year students, as well as seminars in hospital pharmacy (vital sign seminars) for fifth-year students at the Department of Pharmacy of Kyushu University of Health and Welfare have been implemented using patient training models and various patient simulators. The introduction of simulation-based pharmaceutical education, where no patients are present, promotes visually, aurally, and tactilely simulated learning regarding the evaluation of vital signs and implementation of physical assessment when disease symptoms are present or adverse effects occur. A patient simulator also promotes the creation of training programs for emergency and critical care, with which basic as well as advanced life support can be practiced. In addition, an advanced objective structured clinical examination (OSCE) trial has been implemented to evaluate skills regarding vital signs and physical assessments. Pharmacists are required to examine vital signs and conduct physical assessment from a pharmaceutical point of view. The introduction of these pharmacy clinical skills will improve the efficacy of drugs, work for the prevention or early detection of adverse effects, and promote the appropriate use of drugs. It is considered that simulation-based pharmaceutical education is essential to understand physical assessment, and such education will ideally be applied and developed according to on-site practices.

  18. Communication skills of medical students during the OSCE: Gender-specific differences in a longitudinal trend study.

    Science.gov (United States)

    Graf, Joachim; Smolka, Robert; Simoes, Elisabeth; Zipfel, Stephan; Junne, Florian; Holderried, Friederike; Wosnik, Annette; Doherty, Anne M; Menzel, Karina; Herrmann-Werner, Anne

    2017-05-02

    Communication skills are essential in a patient-centred health service and therefore in medical teaching. Although significant differences in communication behaviour of male and female students are known, gender differences in the performance of students are still under-reported. The aim of this study was to analyse gender differences in communication skills of medical students in the context of an OSCE exam (OSCE = Objective Structured Clinical Examination). In a longitudinal trend study based on seven semester-cohorts, it was analysed if there are gender differences in medical students' communication skills. The students (self-perception) and standardized patients (SP) (external perception) were asked to rate the communication skills using uniform questionnaires. Statistical analysis was performed by using frequency analyses and t-tests in SPSS 21. Across all ratings in the self- and the external perception, there was a significant gender difference in favour of female students performing better in the dimensions of empathy, structure, verbal expression and non-verbal expression. The results of male students deteriorated across all dimensions in the external perception between 2011 and 2014. It is important to consider if gender-specific teaching should be developed, considering the reported differences between female and male students.

  19. Patterns of nucleotide diversity and phenotypes of two domestication related genes (OsC1 and Wx) in indigenous rice varieties in Northeast India.

    Science.gov (United States)

    Choudhury, Baharul Islam; Khan, Mohammed Latif; Dayanandan, Selvadurai

    2014-06-16

    During the domestication of crops, individual plants with traits desirable for human needs have been selected from their wild progenitors. Consequently, genetic and nucleotide diversity of genes associated with these selected traits in crop plants are expected to be lower than their wild progenitors. In the present study, we surveyed the pattern of nucleotide diversity of two selected trait specific genes, Wx and OsC1, which regulate amylose content and apiculus coloration respectively in cultivated rice varieties. The analyzed samples were collected from a wide geographic area in Northeast (NE) India, and included contrasting phenotypes considered to be associated with selected genes, namely glutinous and nonglutinous grains and colored and colorless apiculus. No statistically significant selection signatures were detected in both Wx and OsC1gene sequences. However, low level of selection that varied across the length of each gene was evident. The glutinous type varieties showed higher levels of nucleotide diversity at the Wx locus (πtot = 0.0053) than nonglutinous type varieties (πtot = 0.0043). The OsC1 gene revealed low levels of selection among the colorless apiculus varieties with lower nucleotide diversity (πtot = 0.0010) than in the colored apiculus varieties (πtot = 0.0023). The results revealed that functional mutations at Wx and OsC1genes considered to be associated with specific phenotypes do not necessarily correspond to the phenotypes in indigenous rice varieties in NE India. This suggests that other than previously reported genomic regions may also be involved in determination of these phenotypes.

  20. Determination of Trace Amounts of Gold in Environmental Samples by Adsorptive Stripping Voltammetry of Its Complex with Rhodamine Using Osc-Pls

    Directory of Open Access Journals (Sweden)

    A. Akrami

    2012-11-01

    Full Text Available The multivariate calibration method was applied for the determination of trace amounts of gold based on a hanging mercury drop electrode (HMDE in the presence of rhodanine, followed by reduction of adsorbed gold by voltammetric scan using differential pulse modulation The optimum experimental conditions are: rhodanine concentration of 0.20 mg mL-1, pH 5.0, accumulation potential of -600 mV versus Ag/AgCl, accumulation time of 100 sec, scan rate of 30 mV s-1 and pulse height of 100 mV. The calibration matrix for partial least squares (PLS regression was designed with 9 samples. Orthogonal signal correction (OSC is a preprocessing technique used for removing the information unrelated to the target variables based on constrained principal component analysis. OSC is a suitable preprocessing method for PLS calibration without loss of prediction capacity using electrochemical method. The RMSEP for gold determination with PLS and OSC-PLS were 8.51 and 1.94, respectively. This procedure allows the determination of gold in synthetic and real samples with good reliability of the determination. 

  1. Preparation of Composited Graphene/PEDOT:PSS Film for Its Possible Application in Graphene-based Organic Solar Cells

    Institute of Scientific and Technical Information of China (English)

    YU; Yue; LI; Meicheng; CHU; Lihua; YU; Hakki; Wodtke; A.M.; ZHAO; Yan; ZHANG; Zhongmo

    2015-01-01

    The interface between graphene and organic layers is a key factor responsible for the performance of graphene-based organic solar cells(OSCs). In this paper, we focus on coating PEDOT:PSS onto the surface of graphene. We demonstrate two approaches, applying UV/Ozone treatment on graphene and modifying PEDOT:PSS with Zonyl, to get a PEDOT:PSS well-coated graphene film. Our results prove that both methods can be effective to solve the interface issue between graphene and PEDOT: PSS. Thereby it shows a positive application of the composited graphene/PEDOT:PSS film on graphene-based OSCs.

  2. Preparation of Composited Graphene/PEDOT:PSS Film for Its Possible Application in Graphene-based Organic Solar Cells

    Institute of Scientific and Technical Information of China (English)

    YU Yue; LI Meicheng; CHU Lihua; YU Hakki; Wodtke A M; ZHAO Yan; ZHANG Zhongmo

    2015-01-01

    The interface between graphene and organic layers is a key factor responsible for the performance of gra-phene-based organic solar cells (OSCs). In this paper, we focus on coating PEDOT:PSS onto the surface of graphene. We demonstrate two approaches, applying UV/Ozone treatment on graphene and modifying PEDOT:PSS with Zonyl, to get a PEDOT:PSS well-coated graphene film . Our results prove that both methods can be effective to solve the interface issue between graphene and PEDOT: PSS. Thereby it shows a positive application of the composited gra-phene/PEDOT:PSS film on graphene-based OSCs.

  3. A simple framework for assessing technical skills in a resident observed structured clinical examination (OSCE): vaginal laceration repair.

    Science.gov (United States)

    Winkel, Abigail Ford; Lerner, Veronica; Zabar, Sondra R; Szyld, Demian

    2013-01-01

    Educators of trainees in procedure-based specialties need focused assessment tools that are valid, objective, and assess technical skills in a realistic context. A framework for hybrid assessment using standardized patient scenarios and bench skills testing might facilitate evaluation of competency. Seven PGY-1 obstetrics and gynecology residents participated in a hybrid assessment that used observed structured clinical examination (OSCE) by a standardized patient who had sustained a vaginal laceration during vaginal delivery. The residents elicited a history and counseled the patient, and then completed a laceration repair on a pelvic model. The residents were rated on their performance in the scenario, which included issues of cultural competency, rapport-building, patient counseling. The technical skills were videotaped and rated using a modified global assessment form by 2 faculty members on a 3-point scale from "not done" to "partly done" to "well-done." Residents also completed a subjective assessment of the station. Mean technical performance of the residents on the technical skills was 55% "well-done," with a range of 20%-90%. The assessment identified 3 residents as below the mean, and 1 resident with areas of deficiency. Subjective assessment by the residents was that juggling the technical, cognitive, and affective components of the examination was challenging. Technical skills can be included in a case-based assessment using scenarios that address a range of cognitive and affective skills required of physicians. Results may help training programs assess individuals' abilities as well as identify program needs for curricular improvement. This framework might be useful in setting standards for competency and identifying poor performers. Copyright © 2012 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  4. Logistics and preparations for the NPE

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, P.J.; Miller, J.W. [Lawrence Livermore National Lab., CA (United States)

    1994-12-31

    The purpose of this experiment was to simulate a one kiloton nuclear explosion using chemical explosives and try to differentiate the seismic signatures generated from that of previous nuclear detonations. In order to duplicate the geology of nuclear detonations this experiment was carried out in the {open_quotes}N{close_quotes} Tunnel complex at the Nevada Test Site (NTS). This location was particularly appropriate since data is available from previous nearby nuclear events for comparison with data to be collected from the Chemical Kiloton (CKT) Experiment. We operated on a non-interference basis with test program activities. A total of 2.9 million pounds of blasting agent was detonated using five 5 pound Pentolite booster charges, each initiated by a high energy Exploding Bridge Wire (EBW) detonator. The blasting agent consisting of a 50/50 emulsion ANFO mixture; the emulsion being an ammonium nitrate water mixture, and ANFO being an ammonium nitrate fuel oil mixture. The explosive was emplaced at the end of a newly mined drift, designated U12n.25, which branched off an existing drift in {open_quotes}N{close_quotes} Tunnel, U12n.23. A cavity was mined at the end of U12n.25 and instrumented with arrays of Continuous Reflectometry for Radius Versus Time (CORRTEX) cables, thermocouples, and pressure measuring instrumentation for both scientific and safety monitoring purposes. Additional instrumentation, external to the cavity, was installed in several tunnel locations, as well as locations external to the tunnel, and on Ranier Mesa above the point of detonation. More distant measurements were made at various permanently installed seismic stations across the country, as well as at some international locations. In particular, an attempt was made to coordinate this detonation with the National Science Foundation fielding of a seismic array emplaced by Duke University in the southern Sierra-Nevada mountain range (Nevada & California) during mid-September of 1993.

  5. Constraints on Energy Intake in Fish: The Link between Diet Composition, Energy Metabolism, and Energy Intake in Rainbow Trout

    Science.gov (United States)

    Saravanan, Subramanian; Schrama, Johan W.; Figueiredo-Silva, A. Claudia; Kaushik, Sadasivam J.; Verreth, Johan A. J.; Geurden, Inge

    2012-01-01

    The hypothesis was tested that fish fed to satiation with iso-energetic diets differing in macronutrient composition will have different digestible energy intakes (DEI) but similar total heat production. Four iso-energetic diets (2×2 factorial design) were formulated having a contrast in i) the ratio of protein to energy (P/E): high (HP/E) vs. low (LP/E) and ii) the type of non-protein energy (NPE) source: fat vs. carbohydrate which were iso-energetically exchanged. Triplicate groups (35 fish/tank) of rainbow trout were hand-fed each diet twice daily to satiation for 6 weeks under non-limiting water oxygen conditions. Feed intake (FI), DEI (kJ kg−0.8 d−1) and growth (g kg−0.8 d−1) of trout were affected by the interaction between P/E ratio and NPE source of the diet (Ptrout by ∼20%. The diet-induced differences in FI and DEI show that trout did not compensate for the dietary differences in digestible energy or digestible protein contents. Further, changes in body fat store and plasma glucose did not seem to exert a homeostatic feedback control on DEI. Independent of the diet composition, heat production of trout did not differ (P>0.05). Our data suggest that the control of DEI in trout might be a function of heat production, which in turn might reflect a physiological limit related with oxidative metabolism. PMID:22496852

  6. A near-peer teaching program designed, developed and delivered exclusively by recent medical graduates for final year medical students sitting the final objective structured clinical examination (OSCE

    Directory of Open Access Journals (Sweden)

    Sobowale Oluwaseun

    2011-03-01

    Full Text Available Abstract Background The General Medical Council states that teaching doctors and students is important for the care of patients. Our aim was to deliver a structured teaching program to final year medical students, evaluate the efficacy of teaching given by junior doctors and review the pertinent literature. Methods We developed a revision package for final year medical students sitting the Objective Structured Clinical Examination (OSCE. The package was created and delivered exclusively by recent medical graduates and consisted of lectures and small group seminars covering the core areas of medicine and surgery, with a focus on specific OSCE station examples. Students were asked to complete a feedback questionnaire during and immediately after the program. Results One hundred and eighteen completed feedback questionnaires were analysed. All participants stated that the content covered was relevant to their revision. 73.2% stated that junior doctors delivered teaching that is comparable to that of consultant - led teaching. 97.9% stated the revision course had a positive influence on their learning. Conclusions Our study showed that recent medical graduates are able to create and deliver a structured, formal revision program and provide a unique perspective to exam preparation that was very well received by our student cohort. The role of junior doctors teaching medical students in a formal structured environment is very valuable and should be encouraged.

  7. The iOSC3 System: Using Ontologies and SWRL Rules for Intelligent Supervision and Care of Patients with Acute Cardiac Disorders

    Directory of Open Access Journals (Sweden)

    Marcos Martínez-Romero

    2013-01-01

    Full Text Available Physicians in the Intensive Care Unit (ICU are specially trained to deal constantly with very large and complex quantities of clinical data and make quick decisions as they face complications. However, the amount of information generated and the way the data are presented may overload the cognitive skills of even experienced professionals and lead to inaccurate or erroneous actions that put patients’ lives at risk. In this paper, we present the design, development, and validation of iOSC3, an ontology-based system for intelligent supervision and treatment of critical patients with acute cardiac disorders. The system analyzes the patient’s condition and provides a recommendation about the treatment that should be administered to achieve the fastest possible recovery. If the recommendation is accepted by the doctor, the system automatically modifies the quantity of drugs that are being delivered to the patient. The knowledge base is constituted by an OWL ontology and a set of SWRL rules that represent the expert’s knowledge. iOSC3 has been developed in collaboration with experts from the Cardiac Intensive Care Unit (CICU of the Meixoeiro Hospital, one of the most significant hospitals in the northwest region of Spain.

  8. The on scene command and control system (OSC2) : an integrated incident command system (ICS) forms-database management system and oil spill trajectory and fates model

    International Nuclear Information System (INIS)

    Anderson, E.; Galagan, C.; Howlett, E.

    1998-01-01

    The On Scene Command and Control (OSC 2 ) system is an oil spill modeling tool which was developed to combine Incident Command System (ICS) forms, an underlying database, an integrated geographical information system (GIS) and an oil spill trajectory and fate model. The first use of the prototype OSC 2 system was at a PREP drill conducted at the U.S. Coast Guard Marine Safety Office, San Diego, in April 1998. The goal of the drill was to simulate a real-time response over a 36-hour period using the Unified Command System. The simulated spill was the result of a collision between two vessels inside San Diego Bay that caused the release of 2,000 barrels of fuel oil. The hardware component of the system which was tested included three notebook computers, two laser printers, and a poster printer. The field test was a success but it was not a rigorous test of the system's capabilities. The map display was useful in quickly setting up the ICS divisions and groups and in deploying resources. 6 refs., 1 tab., 5 figs

  9. The effect on reliability and sensitivity to level of training of combining analytic and holistic rating scales for assessing communication skills in an internal medicine resident OSCE.

    Science.gov (United States)

    Daniels, Vijay John; Harley, Dwight

    2017-07-01

    Although previous research has compared checklists to rating scales for assessing communication, the purpose of this study was to compare the effect on reliability and sensitivity to level of training of an analytic, a holistic, and a combined analytic-holistic rating scale in assessing communication skills. The University of Alberta Internal Medicine Residency runs OSCEs for postgraduate year (PGY) 1 and 2 residents and another for PGY-4 residents. Communication stations were scored with an analytic scale (empathy, non-verbal skills, verbal skills, and coherence subscales) and a holistic scale. Authors analyzed reliability of individual and combined scales using generalizability theory and evaluated each scale's sensitivity to level of training. For analytic, holistic, and combined scales, 12, 12, and 11 stations respectively yielded a Phi of 0.8 for the PGY-1,2 cohort, and 16, 16, and 14 stations yielded a Phi of 0.8 for the PGY-4 cohort. PGY-4 residents scored higher on the combined scale, the analytic rating scale, and the non-verbal and coherence subscales. A combined analytic-holistic rating scale increased score reliability and was sensitive to level of training. Given increased validity evidence, OSCE developers should consider combining analytic and holistic scales when assessing communication skills. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. OSCE para Competências de Comunicação Clínica e Profissionalismo: Relato de Experiência e Meta-Avaliação

    Directory of Open Access Journals (Sweden)

    Camila Ament Giuliani dos Santos Franco

    Full Text Available RESUMO A comunicação clínica e o profissionalismo estão entre as principais competências médicas e, portanto, devem ter sua avaliação garantida. Nesse contexto, o exame clínico objetivo estruturado (OSCE tem papel fundamental. Objetivos Descrever as etapas de elaboração de um OSCE, bem como a avaliação da qualidade das estações e a percepção do estudante de Medicina sobre a sua realização. Método O estudo é composto pela realização de um OSCE com quatro estações por 16 estudantes de Medicina e pela análise da qualidade psicométrica e aplicação de um questionário de satisfação. Resultados Para os estudantes, o OSCE é o método que melhor avalia e ensina essas competências, ao passo que os testes de múltipla escolha estão no polo oposto quanto à avaliação. Em relação à qualidade múltipla das estações: duas se apresentaram com boa confiabilidade, uma se tornou satisfatória após adequação e uma se revelou inconsistente. Conclusão Mesmo bem avaliadas pelos estudantes, algumas estações apresentaram falhas. A análise do OSCE é fundamental para sua validade e mensurabilidade, em especial para o OSCE de alta aposta.

  11. Constraints on energy intake in fish: the link between diet composition, energy metabolism, and energy intake in rainbow trout.

    Directory of Open Access Journals (Sweden)

    Subramanian Saravanan

    Full Text Available The hypothesis was tested that fish fed to satiation with iso-energetic diets differing in macronutrient composition will have different digestible energy intakes (DEI but similar total heat production. Four iso-energetic diets (2 × 2 factorial design were formulated having a contrast in i the ratio of protein to energy (P/E: high (H(P/E vs. low (L(P/E and ii the type of non-protein energy (NPE source: fat vs. carbohydrate which were iso-energetically exchanged. Triplicate groups (35 fish/tank of rainbow trout were hand-fed each diet twice daily to satiation for 6 weeks under non-limiting water oxygen conditions. Feed intake (FI, DEI (kJ kg(-0.8 d(-1 and growth (g kg(-0.8 d(-1 of trout were affected by the interaction between P/E ratio and NPE source of the diet (P0.05. Our data suggest that the control of DEI in trout might be a function of heat production, which in turn might reflect a physiological limit related with oxidative metabolism.

  12. Organizaciones de la sociedad civil (OSC y el fenómeno histórico de la migración en Jiquilpan, Michoacán

    Directory of Open Access Journals (Sweden)

    Rubén Ramirez Arellano

    2014-12-01

    Full Text Available En Jiquilpan, las organizaciones de la sociedad civil formadas por migrantes ayudan a mejorar las condiciones de su comunidad. Este objetivo en común recuperó la agenda social de la cual no se ocupaba el gobierno. Sin embargo, actualmente representan uno de los actores de transformación más importante en la región, por lo que el gobierno local promueve su articulación con las organizaciones a favor del desarrollo en sus comunidades de origen. La construcción de las relaciones políticas a partir de las estructuras jerárquicas se reproduce desde la familia hasta otras instituciones. De manera notable las organizaciones tienen una base familiar y barrial como un componente cultural sustantivo. La emergencia de las OSC como un actor político en el contexto migratorio, se relaciona con su capacidad de reivindicar la pertenencia a través de la participación en procesos sociales de su lugar de origen y arribo promoviendo relaciones menos jerárquicas entre gobierno y sociedad.

  13. Do primary health centres and hospitals contribute equally towards achievement of the transversal clinical competencies of medical students? Performance on the Objective Structured Clinical Examination (OSCE) in competency acquisition.

    Science.gov (United States)

    Soler-González, Jorge; Buti, Miquel; Boada, Jordi; Ayala, Victoria; Peñascal, Eduard; Rodriguez, Toni

    2016-01-01

    The adaptation of the educational programmes of European faculties of medicine to the European Higher Education Area guidelines has focused curricula design on competence acquisition. Competencies are defined as the achievements of a predetermined level of efficacy in real-world scenarios. Our objective was to assess whether performance on a common competence evaluation test, the Objective Structured Clinical Examination (OSCE), resulted in different scores for second-year students after a practical medical training course took place in a primary health centre (PHC) or in a hospital. A descriptive study was conducted during the 2010-2014 academic year of the OSCE test scores obtained by all second-year students. Faculty of Medicine at the University of Lleida (Catalonia, Spain). We performed a correlation analysis between students who completed their practical medical training at the PHC and hospitals utilising Student's t-test for comparison of means. 423 students who completed internships at the PHC and at hospitals obtained OSCE mean scores of 7.32 (SD; IC) (0.82; 7.18-7.47) points and 7.17 (0.83; 6.07-7.26) points, respectively (p=0.07). Second-year medical students acquired similar competency levels in the two analysed training scenarios. The two areas both serve their teaching purpose. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  14. The influence of precipitation temperature on the properties of ceria–zirconia solid solution composites

    International Nuclear Information System (INIS)

    Cui, Yajuan; Fang, Ruimei; Shang, Hongyan; Shi, Zhonghua; Gong, Maochu; Chen, Yaoqiang

    2015-01-01

    Highlights: • The crystallite size of precipitate increases as the precipitation temperature rises. • The stack of large crystallite can form nanoparticles with big pore size. • Big pore sizes are advantageous to improve the thermal stability. • Phase segregation is restricted in CZ solid solution precipitated at 70 °C. • The reducibility and OSC of the solid solution precipitated at 70 °C are improved. - Abstract: The ceria–zirconia composites (CZ) with a Ce/Zr mass ratio of 1/1 were synthesized by a back-titration method, in which the influence of precipitation temperature on the properties of ceria–zirconia precipitates was investigated. The resulting precipitation and mixed oxides at different precipitation temperatures were then characterized by a range of techniques, including textural properties, X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), H 2 -temperature programmed reduction (H 2 -TPR) as well as oxygen storage capacity (OSC) measurement. The results revealed that ceria–zirconia composites were formed as solid solution and such structure is favored of thermostability and texture properties. In particular, the composite CZ-70 synthesized at 70 °C exhibited prominent thermostability with a surface area of 32 m 2 /g as well as a pore volume of 0.15 cc/g after aging treatment at 1000 °C for 5 h. And this was found to be associated with the wider pore size distribution which maybe owed to the formation of large crystal at the primary stage of precipitation. Additionally, the composite CZ-70 showed excellent reduction property and OSC benefiting from stable texture and structure

  15. G-CLEAN OSC-1809

    Science.gov (United States)

    Technical product bulletin: aka OIL SPILL CLEANUP, this surface washing agent may be applied liberally to heavily weathered oil on rocks or beaches/sand, vegetation, or at full strength on tar balls. Best results if allowed to soak, agitated, or reapplied.

  16. Lawrence Livermore National Laboratory seismic yield determination for the NPE

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, R. [Lawrence Livermore National Lab., CA (United States)

    1994-12-31

    The Lawrence Livermore National Laboratory recorded seismic signals from the Non-Proliferation experiment at the Nevada Test Site on September 22, 1993, at seismic stations near Mina, Nevada; Kanab Utah; Landers, California; and Elko, Nevada. Yields were calculated from these recorded seismic amplitudes at the stations using statistical amplitude- yield regression curves from earlier nuclear experiments performed near the Non-Proliferation experiment. The weighted seismic yield average using these amplitudes is 1.9 kt with a standard deviation of 19%. The calibrating experiments were nuclear, so this yield is equivalent to a 1.9-kt nuclear experiment.

  17. Composition-dependent phase separation effects of organic solar cells using P3HT:PCBM as active layer and chromium oxide as hole transporting layer

    International Nuclear Information System (INIS)

    Qin Pingli; Fang Guojia; Sun Nanhai; Fan Xi; Zheng Qiao; Chen Fei; Wan Jiawei; Zhao Xingzhong

    2011-01-01

    Phase separation of the poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) active layer (ATL) was investigated by varying their relative ratio in the organic solar cells (OSCs). With the help of the UV/visible spectrophotometer, optical microscopy and scanning electron microscope, we found that the cluster of PCBM at the interface or surface was affected by Al cathode, the composition of the blends and thermal annealing. The disc-like shape crystals of PCBM substituted for the needle-like ones at higher PCBM compositions at the ATL/Al interface, which led to stronger contacts and bigger contact area. It could make short circuit current density increase, but may affect the blend morphology and result in parallel resistance and open circuit voltage decreased with the PCBM ratio increasing from 40 to 60%. The microstructure of the P3HT:PCBM ATL, determined by the composition dependent phase separation, supported the optimized performance of the OSCs with the composition of 40-50% PCBM.

  18. Particle size dependence of biogenic secondary organic aerosol molecular composition

    Science.gov (United States)

    Tu, Peijun; Johnston, Murray V.

    2017-06-01

    Formation of secondary organic aerosol (SOA) is initiated by the oxidation of volatile organic compounds (VOCs) in the gas phase whose products subsequently partition to the particle phase. Non-volatile molecules have a negligible evaporation rate and grow particles at their condensation rate. Semi-volatile molecules have a significant evaporation rate and grow particles at a much slower rate than their condensation rate. Particle phase chemistry may enhance particle growth if it transforms partitioned semi-volatile molecules into non-volatile products. In principle, changes in molecular composition as a function of particle size allow non-volatile molecules that have condensed from the gas phase (a surface-limited process) to be distinguished from those produced by particle phase reaction (a volume-limited process). In this work, SOA was produced by β-pinene ozonolysis in a flow tube reactor. Aerosol exiting the reactor was size-selected with a differential mobility analyzer, and individual particle sizes between 35 and 110 nm in diameter were characterized by on- and offline mass spectrometry. Both the average oxygen-to-carbon (O / C) ratio and carbon oxidation state (OSc) were found to decrease with increasing particle size, while the relative signal intensity of oligomers increased with increasing particle size. These results are consistent with oligomer formation primarily in the particle phase (accretion reactions, which become more favored as the volume-to-surface-area ratio of the particle increases). Analysis of a series of polydisperse SOA samples showed similar dependencies: as the mass loading increased (and average volume-to-surface-area ratio increased), the average O / C ratio and OSc decreased, while the relative intensity of oligomer ions increased. The results illustrate the potential impact that particle phase chemistry can have on biogenic SOA formation and the particle size range where this chemistry becomes important.

  19. Particle size dependence of biogenic secondary organic aerosol molecular composition

    Directory of Open Access Journals (Sweden)

    P. Tu

    2017-06-01

    Full Text Available Formation of secondary organic aerosol (SOA is initiated by the oxidation of volatile organic compounds (VOCs in the gas phase whose products subsequently partition to the particle phase. Non-volatile molecules have a negligible evaporation rate and grow particles at their condensation rate. Semi-volatile molecules have a significant evaporation rate and grow particles at a much slower rate than their condensation rate. Particle phase chemistry may enhance particle growth if it transforms partitioned semi-volatile molecules into non-volatile products. In principle, changes in molecular composition as a function of particle size allow non-volatile molecules that have condensed from the gas phase (a surface-limited process to be distinguished from those produced by particle phase reaction (a volume-limited process. In this work, SOA was produced by β-pinene ozonolysis in a flow tube reactor. Aerosol exiting the reactor was size-selected with a differential mobility analyzer, and individual particle sizes between 35 and 110 nm in diameter were characterized by on- and offline mass spectrometry. Both the average oxygen-to-carbon (O ∕ C ratio and carbon oxidation state (OSc were found to decrease with increasing particle size, while the relative signal intensity of oligomers increased with increasing particle size. These results are consistent with oligomer formation primarily in the particle phase (accretion reactions, which become more favored as the volume-to-surface-area ratio of the particle increases. Analysis of a series of polydisperse SOA samples showed similar dependencies: as the mass loading increased (and average volume-to-surface-area ratio increased, the average O ∕ C ratio and OSc decreased, while the relative intensity of oligomer ions increased. The results illustrate the potential impact that particle phase chemistry can have on biogenic SOA formation and the particle size range where this chemistry becomes

  20. Healable Composites

    Science.gov (United States)

    2012-03-28

    oriented fibers and healable polymer matrix 4. Laminate pre-preg layers to form composite panels with minimal voids & defects 5. Characterize the...composites: determine mechanical and crack healing properties (4, 5) Composite (3) Prepreg (2) Polymer (1) Furan (1) Maleimide Healable Composites...Develop pre-preg system of oriented fibers and healable polymer matrix 4. Laminate pre-preg layers to form composite panels with minimal voids & defects

  1. Developments in the photonics program at OSC

    Science.gov (United States)

    Peyghambarian, N.

    2014-10-01

    The photonics program at the College of Optical Sciences started nearly 30 years ago. In 1984, the program was focused on development of femtosecond laser sources and their use in investigating semiconductor carrier dynamics. The program grew into polymer and organic optics in late 1989 and was strengthened by the winning of the CAMP MURI from ONR in 1995 that was focused on multifunctional polymers including photorefractive polymers, organic light emitting diodes and 3D direct laser writing. Also in 1995, the areas of glass waveguide and fiber optic materials and devices were added to the program. In 2008, the optical communication and future internet research was started through winning the CIAN NSF ERC. Expertise in thin films, optical storage and the fundamental aspects of light are elements of the overall research program. Holographic 3D display, autofocus lenses, bio-medical imaging and devices for vision have also been ongoing research areas.

  2. Wood composites

    Science.gov (United States)

    Lars Berglund; Roger M. Rowell

    2005-01-01

    A composite can be defined as two or more elements held together by a matrix. By this definition, what we call “solid wood” is a composite. Solid wood is a three-dimensional composite composed of cellulose, hemicelluloses and lignin (with smaller amounts of inorganics and extractives), held together by a lignin matrix. The advantages of developing wood composites are (...

  3. Dimensionally stable Nafion-polyethylene composite membranes for direct methanol fuel cell applications

    NARCIS (Netherlands)

    Yildirim, M.H.; Stamatialis, Dimitrios; Wessling, Matthias

    2008-01-01

    Nafion ® impregnated Solupor ®, microporous UHMWPE film, (N-PE), Nafion ®117 (N117) and a membrane prepared using a DE2020 Nafion ® dispersion (DE2020) were characterized with respect to their swelling degree (SD), methanol cross-over, proton conductivity and DMFC performance at various methanol

  4. Composite Materials

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    This book deals with the mechanical and physical behavior of composites as influenced by composite geometry. "Composite Materials" provides a comprehensive introduction for researchers and students to modern composite materials research with a special emphasis on the significance of phase geometry......, viscoelastic behavior, and internal stress states. Other physical properties considered are thermal and electrical conductivities, diffusion coefficients, dielectric constants and magnetic permeability. Special attention is given to the effect of pore shape on the mechanical and physical behavior of porous....... The book enables the reader to a better understanding of the behavior of natural composites, improvement of such materials, and design of new materials with prescribed properties. A number of examples are presented: Special composite properties considered are stiffness, shrinkage, hygro-thermal behavior...

  5. Composite gravity and composite supergravity

    International Nuclear Information System (INIS)

    Lukierski, J.

    1982-09-01

    It is known that the composite YM H-gauge theory can be constructed from σ-fields taking values in a symmetric Riemannian space G/H. We extend such a framework to graded σ-fields taking values in supercosets. We show that from supercoset σ-fields one can construct composite gravity, and from supercoset σ-superfields the composite supergravity models. (author)

  6. Composite Territories

    DEFF Research Database (Denmark)

    Nicholas, Paul; Tamke, Martin

    2012-01-01

    and assembly of the fibre reinforced composite structure Composite Territories, in which the property of bending is activated and varied so as to match solely through material means a desired form. This case study demonstrates how one might extend the geometric model so that it is able to engage and reconcile...

  7. Computational composites

    DEFF Research Database (Denmark)

    Vallgårda, Anna K. A.; Redström, Johan

    2007-01-01

    Computational composite is introduced as a new type of composite material. Arguing that this is not just a metaphorical maneuver, we provide an analysis of computational technology as material in design, which shows how computers share important characteristics with other materials used in design...... and architecture. We argue that the notion of computational composites provides a precise understanding of the computer as material, and of how computations need to be combined with other materials to come to expression as material. Besides working as an analysis of computers from a designer’s point of view......, the notion of computational composites may also provide a link for computer science and human-computer interaction to an increasingly rapid development and use of new materials in design and architecture....

  8. Hybrid composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available mixed short sisal/glass hybrid fibre reinforced low density polyethylene composites was investigated by Kalaprasad et al [25].Chemical surface modifications such as alkali, acetic anhydride, stearic acid, permanganate, maleic anhydride, silane...

  9. National platform electromobility. Interim report of the NPE AG 6 - Education and qualification; Nationale Plattform Elektromobilitaet. Zwischenbericht der NPE AG 6 - Ausbildung und Qualifizierung

    Energy Technology Data Exchange (ETDEWEB)

    Goericke, Dietmar [Forschungsvereinigung Verbrennungskraftmaschinen e.V., Frankfurt am Main (Germany)

    2010-07-01

    On behalf of the working group 6 ''Education and qualification'' of the national platform electromobility arranged by the Federal Government, the academic and occupational education and advanced training had to be aligned to the targets of the national platform electromobility. In the context of an ABC analysis, the academic and professional educational offerings in Germany were analyzed according to the strengths and weaknesses. From this, recommendations for action were derived for the compensation of these deficits.

  10. Resin composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Peutzfeldt, Anne; Lussi, Adrian

    2014-01-01

    OBJECTIVE: To investigate how the modulus of elasticity of resin composites influences marginal quality in restorations submitted to thermocyclic and mechanical loading. METHODS: Charisma, Filtek Supreme XTE and Grandio were selected as they were found to possess different moduli of elasticity...... of resin composite (p=0.81) on the quality of dentine margins was observed, before or after loading. Deterioration of all margins was evident after loading (p....008). CONCLUSIONS: The resin composite with the highest modulus of elasticity resulted in the highest number of gap-free enamel margins but with an increased incidence of paramarginal enamel fractures. CLINICAL SIGNIFICANCE: The results from this study suggest that the marginal quality of restorations can...

  11. Composite Territories

    DEFF Research Database (Denmark)

    Nicholas, Paul; Tamke, Martin

    2012-01-01

    for the varied composition of material, an extension of the digital chain that foregrounds a new need to engage materials at multiple scales within the design process. Recognising that the process of making materials affords perspectives not available with found materials, this paper reports the design...... and assembly of the fibre reinforced composite structure Composite Territories, in which the property of bending is activated and varied so as to match solely through material means a desired form. This case study demonstrates how one might extend the geometric model so that it is able to engage and reconcile......Today, material performance is regarded as one of the richest sources of innovation. Accordingly, architecture is shifting to practices by which the computational generation of form is directly driven by material characteristics. At the same time, there is a growing technological means...

  12. Composite material

    Science.gov (United States)

    Hutchens, Stacy A [Knoxville, TN; Woodward, Jonathan [Solihull, GB; Evans, Barbara R [Oak Ridge, TN; O'Neill, Hugh M [Knoxville, TN

    2012-02-07

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  13. Computational Composites

    DEFF Research Database (Denmark)

    Vallgårda, Anna K. A.

    to understand the computer as a material like any other material we would use for design, like wood, aluminum, or plastic. That as soon as the computer forms a composition with other materials it becomes just as approachable and inspiring as other smart materials. I present a series of investigations of what...... Computational Composite, and Telltale). Through the investigations, I show how the computer can be understood as a material and how it partakes in a new strand of materials whose expressions come to be in context. I uncover some of their essential material properties and potential expressions. I develop a way...

  14. Compositional translation

    NARCIS (Netherlands)

    Appelo, Lisette; Janssen, Theo; Jong, de F.M.G.; Landsbergen, S.P.J.

    1994-01-01

    This book provides an in-depth review of machine translation by discussing in detail a particular method, called compositional translation, and a particular system, Rosetta, which is based on this method. The Rosetta project is a unique combination of fundamental research and large-scale

  15. Composing compositions

    Energy Technology Data Exchange (ETDEWEB)

    DeBoodt, M. F. L. P.; Verdonck, O. F.

    1985-01-22

    A process is disclosed for producing compost and composting compositions having a high nitrogen content and being particularly advantageous for use as fertilizers, said process utilizing petroleum sludge and an organic biomass which preferably contains wood industry residue and organic waste products.

  16. Composite thermocouples

    International Nuclear Information System (INIS)

    Debeir, R.P.

    1975-01-01

    As a rule, a composite thermocouple is a thermocouple where one or more components (wires, sheath, insulation) differ in kind between the hot junction measurement point and the cold termination with ordinary cables going on to measurement instrumentation. Three categories of such thermocouples are discussed: composite thermocouples having in common the continuity of the thermoelement wires over complete length, and different sheaths and insulation for the high temperature and intermediate temperature parts; those with different thermoelement wires, sheaths, and insulators for the high and intermediate temperature parts; a third category includes the high temperature thermoelements insulated by Al 2 O 3 or BeO and sheathed with a refractory metal, and with the intermediate temperature part made of 2Cr-Al couples, MgO insulated, and stainless steel or inconel sheathed

  17. Explosive compositions

    Energy Technology Data Exchange (ETDEWEB)

    1971-04-01

    An explosive composition containing ammonium nitrate consists of (1) from 40 to 75 Pt. by wt of particulate ammonium nitrate, (2) from 20 to 35 Pt. by wt of a solution selected from the group consisting of aqueous magnesium nitrate, aqueous ammonium nitrate and aqueous ammoniacal ammonium nitrate; and (3) at least 2 Pt. by wt of a setting agent selected from the group consisting of alkaline earth metal oxides, zinc oxide, lead monoxide, calcined dolomitic limestone, anhydrous calcium sulfate, anhydrous magnesium sulfate, anhydrous sodium tetrapyrophosphate and anhydrous sodium thiosulfate. The setting agent is further characterized in setting the composition to a solid material which contains solvent used in the liquid phase. (Abstract only - original article not available from T.U.)

  18. Explosive composition

    Energy Technology Data Exchange (ETDEWEB)

    Slykhouse, T E

    1968-05-09

    An ammonium nitrate explosive composition is characterized in that it contains from 40 to 75 parts by wt of particulate ammonium nitrate, from 20 to 35 parts by wt of a solution selected from the group consisting of aqueous magnesium nitrate, aqueous ammonium nitrate, and aqueous ammoniacal ammonium nitrate. It also contains at least 2 parts by wt of a setting agent selected from the group consisting of alkaline earth metal oxides, zinc oxide, lead monoxide, calcined dolomitic limestone, substantially anhydrous calcium sulfate, substantially anhydrous magnesium sulfate, substantially anhydrous sodium tetrapyrophosphate and substantially anhydrous sodium thiosulfate. The setting agent is further characterized in that it sets the composition to a solid material which contains solvent used in the liquid phase. (12 claims)

  19. Concrete compositions and methods

    Science.gov (United States)

    Chen, Irvin; Lee, Patricia Tung; Patterson, Joshua

    2015-06-23

    Provided herein are compositions, methods, and systems for cementitious compositions containing calcium carbonate compositions and aggregate. The compositions find use in a variety of applications, including use in a variety of building materials and building applications.

  20. Dietary nutrient composition affects digestible energy utilisation for growth: a study on Nile tilapia (Oreochromis niloticus) and a literature comparison across fish species

    NARCIS (Netherlands)

    Schrama, J.W.; Subramanian, S.; Geurden, I.; Heinsbroek, L.T.N.; Kaushik, S.J.; Verreth, J.A.J.

    2012-01-01

    The effect of the type of non-protein energy (NPE) on energy utilisation in Nile tilapia was studied, focusing on digestible energy utilisation for growth (kgDE). Furthermore, literature data on kgDE across fish species were analysed in order to evaluate the effect of dietary macronutrient

  1. Composite materials

    International Nuclear Information System (INIS)

    Sambrook, D.J.

    1976-01-01

    A superconductor composite is described comprising at least one longitudinally extending superconductor filament or bundle of sub-filaments, each filament or bundle of sub-filaments being surrounded by and in good electrical contact with a matrix material, the matrix material comprising a plurality of longitudinally extending cells of a metal of high electrical conductivity surrounded by a material of lower electrical conductivity. The high electrical conductivity material surrounding the superconducting filament or bundle of sub-filaments is interrupted by a radially extending wall of the material of the lower electrical conductivity, the arrangement being such that at least two superconductor filaments or sub-filaments are circumferentially circumscribed by a single annulus of the material of high electrical conductivity. The annulus is electrically interrupted by a radially extending wall of the material of low electrical conductivity

  2. Acrylic composition

    International Nuclear Information System (INIS)

    Kimura, Tadashi; Ozeki, Takao; Kobayashi, Juichi; Nakamoto, Hideo; Meda, Yutaka.

    1969-01-01

    An acrylic composition and a process for the production of an easily hardenable coating material by irradiating with active energy, particularly electron beams and ultraviolet light, are provided using a mixture of 10%-100% by weight of an unsaturated compound and 90%-0% of a vinyl monomer. The composition has a high degree of polymerization, low volatility, low viscosity and other properties similar to thermosetting acrylic or amino alkyd resins. The aforesaid unsaturated compound is produced by primarily reacting saturated cyclocarboxylic anhydride and/or alpha-, beta-ethylene unsaturated carboxylic anhydride and by secondarily reacting an epoxy radical-containing vinyl monomer by addition reaction with polyhydric alcohols. Each reaction is conducted in the presence of a tertiary amino radical-containing vinyl monomer as a catalyst. The cross-linking is effected generally with an electron beam accelerator of 0.1-2.0 MeV or with a light beam in the 2,000-8,000A range in the presence of a photosensitive agent. In one example, 62 parts of ethylene glycol and 196 parts of maleic anhydride were dissolved in a mixture consisting of 100 parts of n-butyl methacrylate and 30 parts of styrene. To the mixture were added 5 parts of 2-methyl 5 vinyl piridine and 0.005 part of hydroquinone monomethyl ether. After the reaction at 90 0 C for 3 hours, a compound HOC:O-CH=CHC:OCH 2 CH 2 C:OOH was produced. To this solution were added 285 parts of glycidyl methacrylate. After the reaction at 90 0 C for 6 hours, 95% of the carboxylic acids reacted with epoxy radicals. Fourteen examples are given. (Iwakiri, K.)

  3. Analysis of the exclusive final state npe(+)e(-) in the quasi-free np reaction

    Czech Academy of Sciences Publication Activity Database

    Adamczewski-Musch, J.; Arnold, O.; Atomssa, E. T.; Chlad, Lukáš; Kugler, Andrej; Rodriguez Ramos, Pablo; Sobolev, Yuri, G.; Svoboda, Ondřej; Tlustý, Pavel; Wagner, Vladimír

    2017-01-01

    Roč. 53, č. 7 (2017), č. článku 149. ISSN 1434-6001 R&D Projects: GA ČR GA13-06759S Institutional support: RVO:61389005 Keywords : HADES collaboration * heavy ion collisions * cross section Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 2.833, year: 2016

  4. The NPE gas tracer test and the development of on-site inspection techniques

    International Nuclear Information System (INIS)

    Carrigan, C.; Heinle, R.; Zucca, J.J.

    1995-01-01

    Tracer gases emplaced in or near the detonation cavity of the 1-kiloton Non-Proliferation Event required 1.5 and 13.5 months for sulfur hexaflouride and helium-3, respectively, to reach the surface of Rainier Mesa from an emplacement depth of 400 meters. The sites that first produced tracer gases are those located in known faults and fractures. Numerical modeling suggests that transport to the surface is accomplished within this time frame through atmospheric pumping along high permeability pathways such as fractures. The difference in travel time between the two tracers is due to differences in gas diffusivity and can also be explained by our numerical modeling. (author)

  5. Distance effects on regional discriminants along a seismic profile in Northwest Nevada; NPE and nuclear results

    Energy Technology Data Exchange (ETDEWEB)

    McCormack, D.A. [AWE Blacknest, Berkshire (United Kingdom); Priestley, K.F. [Univ. of Cambridge (United Kingdom); Patton, H.J. [Lawrence Livermore National Lab., CA (United States)

    1994-12-31

    To address questions of discriminant transportability, it is important to understand how discriminants based on regional seismic phases are affected by regional variations in velocity structure. To examine this issue, we have recorded two explosions, the nuclear explosion Kinibito and the Non-Proliferation Experiment along a 300 km-long profile through western Nevada. We use these data to investigate the stability with distance of several proposed seismic discriminants. In this study we first estimate the apparent attenuation of the regional phases. We compare attenuation corrected amplitude ratios for P{sub n}/L{sub g} and P{sub g}/L{sub g}, and spectral ratios for P{sub n}, P{sub g}, and L{sub g}, as a function of distance along the profile. We make these comparisons for the vertical component and for the total vector resultant using all three components of motion.

  6. Metallic composite materials

    International Nuclear Information System (INIS)

    Frommeyer, G.

    1987-01-01

    The structure and properties of metallic composite materials and composite materials with metallic matrix are considered. In agreement with the morphology of constituent phases the following types of composite materials are described: dispersion-strengthened composite materials; particle-reinforced composite materials; fibrous composite materials; laminar composite materials. Data on strength and electric properties of the above-mentioned materials, as well as effect of the amount, location and geometric shape of the second phase on them, are presented

  7. Shaped fiber composites

    Science.gov (United States)

    Kinnan, Mark K.; Roach, Dennis P.

    2017-12-05

    A composite article is disclosed that has non-circular fibers embedded in a polymer matrix. The composite article has improved damage tolerance, toughness, bending, and impact resistance compared to composites having traditional round fibers.

  8. Confirmatory Composite Analysis

    NARCIS (Netherlands)

    Schuberth, Florian; Henseler, Jörg; Dijkstra, Theo K.

    2018-01-01

    We introduce confirmatory composite analysis (CCA) as a structural equation modeling technique that aims at testing composite models. CCA entails the same steps as confirmatory factor analysis: model specification, model identification, model estimation, and model testing. Composite models are

  9. Properties of CMR composites

    Indian Academy of Sciences (India)

    Unknown

    Department of Metallurgical Engineering and Materials Science, Indian. Institute ... Colossal magnetoresistance (CMR) composites form an interesting field ..... field and composition sensitive competition between the positive and negative MR.

  10. Composite Structures Manufacturing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Composite Structures Manufacturing Facility specializes in the design, analysis, fabrication and testing of advanced composite structures and materials for both...

  11. Composites Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The purpose of the Composites Characterization Laboratory is to investigate new and/or modified matrix materials and fibers for advanced composite applications both...

  12. Process conditions and volumetric composition in composites

    DEFF Research Database (Denmark)

    Madsen, Bo

    2013-01-01

    The obtainable volumetric composition in composites is linked to the gravimetric composition, and it is influenced by the conditions of the manufacturing process. A model for the volumetric composition is presented, where the volume fractions of fibers, matrix and porosity are calculated...... as a function of the fiber weight fraction, and where parameters are included for the composite microstructure, and the fiber assembly compaction behavior. Based on experimental data of composites manufactured with different process conditions, together with model predictions, different types of process related...... effects are analyzed. The applied consolidation pressure is found to have a marked effect on the volumetric composition. A power-law relationship is found to well describe the found relations between the maximum obtainable fiber volume fraction and the consolidation pressure. The degree of fiber...

  13. Conducting compositions of matter

    Science.gov (United States)

    Viswanathan, Tito (Inventor)

    2000-01-01

    The invention provides conductive compositions of matter, as well as methods for the preparation of the conductive compositions of matter, solutions comprising the conductive compositions of matter, and methods of preparing fibers or fabrics having improved anti-static properties employing the conductive compositions of matter.

  14. Corrosion resistant composite materials

    International Nuclear Information System (INIS)

    Ul'yanin, E.A.

    1986-01-01

    Foundations for corrosion-resistant composite materials design are considered with account of components compatibility. Fibrous and lamellar composites with metal matrix, dispersion-hardened steels and alloys, refractory metal carbides-, borides-, nitrides-, silicides-based composites are described. Cermet compositions and fields of their application, such as protective coatings for operation in agressive media at high temperatures, are presented

  15. Volumetric composition in composites and historical data

    DEFF Research Database (Denmark)

    Lilholt, Hans; Madsen, Bo

    2013-01-01

    The obtainable volumetric composition in composites is of importance for the prediction of mechanical and physical properties, and in particular to assess the best possible (normally the highest) values for these properties. The volumetric model for the composition of (fibrous) composites gives...... guidance to the optimal combination of fibre content, matrix content and porosity content, in order to achieve the best obtainable properties. Several composite materials systems have been shown to be handleable with this model. An extensive series of experimental data for the system of cellulose fibres...... and polymer (resin) was produced in 1942 – 1944, and these data have been (re-)analysed by the volumetric composition model, and the property values for density, stiffness and strength have been evaluated. Good agreement has been obtained and some further observations have been extracted from the analysis....

  16. Democratization in Albania: The OSCE, NATO and the European Union

    Science.gov (United States)

    2010-06-01

    html? maca =en-rss-en-all-1573-rdf (accessed 4 March 2010). 263 Manuel Montobbio de Balanzo, Spanish Ambassador to Albania, http://www.dw- world.de/dw...article/0,,5259561,00.html? maca =en-rss-en-all-1573-rdf (accessed 4 March 2010). 264 Reinhard Priebe, The Western Balkan European Perspective, http...world.de/dw/article/0,,5259561,00.html? maca =en-rss-en-all-1573-rdf (accessed 4 March 2010). European Commission Enlargement, Albania – Questions

  17. Compositional Advantage and Strategy

    DEFF Research Database (Denmark)

    Li, Xin

    advantage is redefined as the attractiveness of the composition of the producer’s offering in terms of scope and perceived value/price ratio. I identify five ways or basic compositional strategies to improve the value/price ratio. A firm may have an overall compositional strategy that is composed of some......In this paper, I first critique the composition-based view of Yadong Luo and John Child for understanding how resource-poor firms survive and thrive. To remedy the deficiencies in their perspective, I then propose a dynamic theory of compositional advantage and strategy. Here, the compositional...... or all of the five basic compositional strategies. I argue there are three indispensable key success factors for a composition-based competition, i.e., aspiration (ambition-position asymmetry), attitude (being ALERT), and action (turning asymmetry into advantage). I also discuss the particular relevance...

  18. Conductive polypropylene composites

    International Nuclear Information System (INIS)

    Koszkul, J.

    1997-01-01

    The results of studies on polypropylene composites with three sorts of Polish-made carbon blacks were presented. It was found that composite of 20% black content had properties of an electrically conducting material

  19. Radiation curable adhesive compositions and composite structures

    International Nuclear Information System (INIS)

    Brenner, W.

    1984-01-01

    This disclosure relates to novel adhesive compositions and composite structures utilizing the same, wherein said adhesive compositions contain an elastomer, a chemically compatible ethylenically unsaturated monomer, a tackifier, an adhesion promoter, and optionally, pigments, fillers, thickeners and flow control agents which are converted from the liquid to the solid state by exposure to high energy ionizing radiation such as electron beam. A particularly useful application for such adhesive compositions comprises the assembly of certain composite structures or laminates consisting of, for example, a fiber flocked rubber sheet and a metal base with the adhesive fulfilling the multiple functions of adhering the flocked fiber to the rubber sheet as well as adhering the rubber sheet to the metal base. Optionally, the rubber sheet itself may also be cured at the same time as the adhesive composition with all operations being carried out at ambient temperatures and in the presence of air, with exposure of said assembly to selected dosages of high energy ionizing radiation. These adhesive compositions contain no solvents thereby almost eliminating air pollution or solvent toxicity problems, and offer substantial savings in energy and labor as they are capable of curing in very short time periods without the use of external heat which might damage the substrate

  20. Nano-composite materials

    Science.gov (United States)

    Lee, Se-Hee; Tracy, C. Edwin; Pitts, J. Roland

    2010-05-25

    Nano-composite materials are disclosed. An exemplary method of producing a nano-composite material may comprise co-sputtering a transition metal and a refractory metal in a reactive atmosphere. The method may also comprise co-depositing a transition metal and a refractory metal composite structure on a substrate. The method may further comprise thermally annealing the deposited transition metal and refractory metal composite structure in a reactive atmosphere.

  1. Amorphous metal composites

    International Nuclear Information System (INIS)

    Byrne, M.A.; Lupinski, J.H.

    1984-01-01

    This patent discloses an improved amorphous metal composite and process of making the composite. The amorphous metal composite comprises amorphous metal (e.g. iron) and a low molecular weight thermosetting polymer binder. The process comprises placing an amorphous metal in particulate form and a thermosetting polymer binder powder into a container, mixing these materials, and applying heat and pressure to convert the mixture into an amorphous metal composite

  2. Microgel polymer composite fibres

    OpenAIRE

    Kehren, Dominic

    2014-01-01

    In this thesis some novel ideas and advancements in the field of polymer composite fibres, specifically microgel-based polymer composite fibres have been achieved. The main task was to investigate and understand the electrospinning process of microgels and polymers and the interplay of parameter influences, in order to fabricate reproducible and continuously homogenous composite fibres. The main aim was to fabricate a composite material which combines the special properties of polymer fibres ...

  3. Two-boson composites

    DEFF Research Database (Denmark)

    Tichy, Malte C.; Bouvrier, P. Alexander; Mølmer, Klaus

    2013-01-01

    Composite bosons made of two bosonic constituents exhibit deviations from ideal bosonic behavior due to their substructure. This deviation is reflected by the normalization ratio of the quantum state of N composites. We find a set of saturable, efficiently evaluable bounds for this indicator, which...... quantifies the bosonic behavior of composites via the entanglement of their constituents. We predict an abrupt transition between ordinary and exaggerated bosonic behavior in a condensate of two-boson composites....

  4. Infiltrated carbon foam composites

    Science.gov (United States)

    Lucas, Rick D. (Inventor); Danford, Harry E. (Inventor); Plucinski, Janusz W. (Inventor); Merriman, Douglas J. (Inventor); Blacker, Jesse M. (Inventor)

    2012-01-01

    An infiltrated carbon foam composite and method for making the composite is described. The infiltrated carbon foam composite may include a carbonized carbon aerogel in cells of a carbon foam body and a resin is infiltrated into the carbon foam body filling the cells of the carbon foam body and spaces around the carbonized carbon aerogel. The infiltrated carbon foam composites may be useful for mid-density ablative thermal protection systems.

  5. Advanced composites for windmills

    Science.gov (United States)

    Bourquardez, G.

    A development status assessment is conducted for advanced composite construction techniques for windmill blade structures which, as in the case of composite helicopter rotors, promise greater reliability, longer service life, superior performance, and lower costs. Composites in wind turbine applications must bear aerodynamic, inertial and gravitational loads in complex interaction cycles. Attention is given to large Darrieus-type vertical axis windmills, to which composite construction methods may offer highly effective pitch-control mechanisms, especially in the 'umbrella' configuration.

  6. Exotic composite vector boson

    International Nuclear Information System (INIS)

    Akama, K.; Hattori, T.; Yasue, M.

    1991-01-01

    An exotic composite vector boson V is introduced in two dynamical models of composite quarks, leptons, W, and Z. One is based on four-Fermi interactions, in which composite vector bosons are regarded as fermion-antifermion bound states and the other is based on the confining SU(2) L gauge model, in which they are given by scalar-antiscalar bound states. Both approaches describe the same effective interactions for the sector of composite quarks, leptons, W, Z, γ, and V

  7. Explosive composition containing water

    Energy Technology Data Exchange (ETDEWEB)

    Cattermole, G.R.; Lyerly, W.M.; Cummings, A.M.

    1971-11-26

    This addition to Fr. 1,583,223, issued 31 May 1968, describes an explosive composition containing a water in oil emulsion. The composition contains an oxidizing mineral salt, a nitrate base salt as sensitizer, water, an organic fuel, a lipophilic emulsifier, and incorporates gas bubbles. The composition has a performance which is improved over and above the original patent.

  8. Composition: Unity - Diversity series

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2015-01-01

    Unity-Diversity series are open compositions to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". This work is licensed under a Creative Commons "by-nc" License. You may for non-commercial purposes use and distribute it...

  9. Adhesive compositions and methods

    Science.gov (United States)

    Allen, Scott D.; Sendijarevic, Vahid; O'Connor, James

    2017-12-05

    The present invention encompasses polyurethane adhesive compositions comprising aliphatic polycarbonate chains. In one aspect, the present invention encompasses polyurethane adhesives derived from aliphatic polycarbonate polyols and polyisocyanates wherein the polyol chains contain a primary repeating unit having a structure:. In another aspect, the invention provides articles comprising the inventive polyurethane compositions as well as methods of making such compositions.

  10. Aerogel / Polymer Composite Materials

    Science.gov (United States)

    Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Roberson, Luke B. (Inventor); Clayton, LaNetra M. (Inventor)

    2017-01-01

    The invention provides new composite materials containing aerogels blended with thermoplastic polymer materials at a weight ratio of aerogel to thermoplastic polymer of less than 20:100. The composite materials have improved thermal insulation ability. The composite materials also have better flexibility and less brittleness at low temperatures than the parent thermoplastic polymer materials.

  11. Composition: Four Rules

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2013-01-01

    Cue Rondo is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". This work is licensed under a Creative Commons "by-nc" License. You may for non-commercial purposes use and distribute it, performanc...

  12. Compositional Advantage and Strategy

    DEFF Research Database (Denmark)

    Li, Xin

    In this paper, I first critique the composition-based view of Yadong Luo and John Child for understanding how resource-poor firms survive and thrive. To remedy the deficiencies in their perspective, I then propose a dynamic theory of compositional advantage and strategy. Here, the compositional...... advantage is redefined as the attractiveness of the composition of the producer’s offering in terms of scope and perceived value/price ratio. I identify five ways or basic compositional strategies to improve the value/price ratio. A firm may have an overall compositional strategy that is composed of some...... of the present theory to understanding Chinese firms. I conclude with managerial implications and suggestions for future research....

  13. Hydrogen storage compositions

    Science.gov (United States)

    Li, Wen; Vajo, John J.; Cumberland, Robert W.; Liu, Ping

    2011-04-19

    Compositions for hydrogen storage and methods of making such compositions employ an alloy that exhibits reversible formation/deformation of BH.sub.4.sup.- anions. The composition includes a ternary alloy including magnesium, boron and a metal and a metal hydride. The ternary alloy and the metal hydride are present in an amount sufficient to render the composition capable of hydrogen storage. The molar ratio of the metal to magnesium and boron in the alloy is such that the alloy exhibits reversible formation/deformation of BH.sub.4.sup.- anions. The hydrogen storage composition is prepared by combining magnesium, boron and a metal to prepare a ternary alloy and combining the ternary alloy with a metal hydride to form the hydrogen storage composition.

  14. Chemical vapor composites (CVC)

    International Nuclear Information System (INIS)

    Reagan, P.

    1993-01-01

    The Chemical Vapor Composite, CVC trademark , process fabricates composite material by simply mixing particles (powders and or fibers) with CVD reactants which are transported and co-deposited on a hot substrate. A key feature of the CVC process is the control provided by varing the density, geometry (aspect ratio) and composition of the entrained particles in the matrix material, during deposition. The process can fabricate composite components to net shape (± 0.013 mm) on a machined substrate in a single step. The microstructure of the deposit is described and several examples of different types of particles in the matrix are illustrated. Mechanical properties of SiC composite material fabricated with SiC powder and fiber will be presented. Several examples of low cost ceramic composite products will be shown. (orig.)

  15. Polymer compositions and methods

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Scott D.; Willkomm, Wayne R.

    2018-02-06

    The present invention encompasses polyurethane compositions comprising aliphatic polycarbonate chains. In one aspect, the present invention encompasses polyurethane foams, thermoplastics and elastomers derived from aliphatic polycarbonate polyols and polyisocyanates wherein the polyol chains contain a primary repeating unit having a structure: ##STR00001## In another aspect, the invention provides articles comprising the inventive foam and elastomer compositions as well as methods of making such compositions.

  16. Continuous Fiber Ceramic Composites

    Energy Technology Data Exchange (ETDEWEB)

    Fareed, Ali [Honeywell Advanced Composites Inc. (HACI), Newark, DE (United States); Craig, Phillip A. [Honeywell Advanced Composites Inc. (HACI), Newark, DE (United States)

    2002-09-01

    Fiber-reinforced ceramic composites demonstrate the high-temperature stability of ceramics--with an increased fracture toughness resulting from the fiber reinforcement of the composite. The material optimization performed under the continuous fiber ceramic composites (CFCC) included a series of systematic optimizations. The overall goals were to define the processing window, to increase the robustinous of the process, to increase process yield while reducing costs, and to define the complexity of parts that could be fabricated.

  17. Composite Material Switches

    Science.gov (United States)

    Javadi, Hamid (Inventor)

    2002-01-01

    A device to protect electronic circuitry from high voltage transients is constructed from a relatively thin piece of conductive composite sandwiched between two conductors so that conduction is through the thickness of the composite piece. The device is based on the discovery that conduction through conductive composite materials in this configuration switches to a high resistance mode when exposed to voltages above a threshold voltage.

  18. Skin barrier composition

    International Nuclear Information System (INIS)

    Osburn, F.G.

    1985-01-01

    A skin barrier composition comprises a mixture of a copolymer resin of ethylene and vinyl acetate (EVA), and a water-insoluble dry tack-providing elastomer such as polyisobutylene. The composition after mixing and molding, is subjected to ionizing irradiation to form cross-linked polymer networks of the EVA. The compositions have exceptional properties for use as barrier sheets, rings, or strips in ostomy, wound drainage, and incontinence devices. (author)

  19. Skin barrier composition

    Energy Technology Data Exchange (ETDEWEB)

    Osburn, F G

    1985-06-12

    A skin barrier composition comprises a mixture of a copolymer resin of ethylene and vinyl acetate (EVA), and a water-insoluble dry tack-providing elastomer such as polyisobutylene. The composition after mixing and molding, is subjected to ionizing irradiation to form cross-linked polymer networks of the EVA. The compositions have exceptional properties for use as barrier sheets, rings, or strips in ostomy, wound drainage, and incontinence devices.

  20. Zooplankton body composition

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2013-01-01

    groups body composition is size independent. Exceptions are protozoans, chaetognaths, and pteropods, where larger individuals become increasingly watery. I speculate about the dichotomy in body composition and argue that differences in feeding mechanisms and predator avoidance strategies favor either......I compiled literature on zooplankton body composition, from protozoans to gelatinous plankton, and report allometric relations and average body composition. Zooplankton segregate into gelatinous and non-gelatinous forms, with few intermediate taxa (chaetognaths, polychaetes, and pteropods). In most...... a watery or a condensed body form, and that in the intermediate taxa the moderately elevated water content is related to buoyancy control and ambush feeding...

  1. Electrically conductive cellulose composite

    Science.gov (United States)

    Evans, Barbara R.; O'Neill, Hugh M.; Woodward, Jonathan

    2010-05-04

    An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

  2. Composite Finite Sums

    KAUST Repository

    Alabdulmohsin, Ibrahim M.

    2018-01-01

    In this chapter, we extend the previous results of Chap. 2 to the more general case of composite finite sums. We describe what composite finite sums are and how their analysis can be reduced to the analysis of simple finite sums using the chain rule. We apply these techniques, next, on numerical integration and on some identities of Ramanujan.

  3. Composite Finite Sums

    KAUST Repository

    Alabdulmohsin, Ibrahim M.

    2018-03-07

    In this chapter, we extend the previous results of Chap. 2 to the more general case of composite finite sums. We describe what composite finite sums are and how their analysis can be reduced to the analysis of simple finite sums using the chain rule. We apply these techniques, next, on numerical integration and on some identities of Ramanujan.

  4. Fundamental partial compositeness

    DEFF Research Database (Denmark)

    Sannino, Francesco; Strumia, Alessandro; Tesi, Andrea

    2016-01-01

    We construct renormalizable Standard Model extensions, valid up to the Planck scale, that give a composite Higgs from a new fundamental strong force acting on fermions and scalars. Yukawa interactions of these particles with Standard Model fermions realize the partial compositeness scenario. Unde...

  5. Wood thermoplastic composites

    Science.gov (United States)

    Daniel F. Caulfield; Craig Clemons; Rodney E. Jacobson; Roger M. Rowell

    2005-01-01

    The term “wood-plastic composites” refers to any number of composites that contain wood (of any form) and either thermoset or thermoplastic polymers. Thermosets or thermoset polymers are plastics that, once cured, cannot be remelted by heating. These include cured resins, such as epoxies and phenolics, plastics with which the forest products industry is most familiar (...

  6. New antifungal compositions

    NARCIS (Netherlands)

    Stark, J.; Rijn, van F.T.J.; Krieken, van der W.M.; Stevens, L.H.

    2008-01-01

    The present invention relates to a process for the treatment of an agricultural product which comprises the addition of a composition which comprises phosphite and natamycin to the agricultural product wherein the composition comprises preferably less than 0.1 g lignosulphonate, more preferably less

  7. Radiolabelled sucralfate compositions

    International Nuclear Information System (INIS)

    Vasquez, T.E.; Bridges, R.L.; Braunstein, P.; Jansholt, A.

    1984-01-01

    A novel radiopharmaceutical composition comprising an aqueous solution or suspension containing a radiolabelled sucralfate or sucralfate derivative or precursor is claimed. The composition is effective for in vivo scintigraphic imaging of the gastrointestinal muscosal areas in humans. The sucralfate is combined with a radiolabelled albumin or other protein or protein derivative under acidic conditions

  8. Mechanical response of composites

    NARCIS (Netherlands)

    Camanho, Pedro P.; Dávila, C.G.; Pinho, Silvestre T.; Remmers, J.J.C.

    2008-01-01

    This book contains twelve selected papers presented at the ECCOMAS Thematic Conference ? Mechanical Response of Composites, and the papers presented by the three plenary speakers. It describes recent advances in the field of analysis models for the mechanical response of advanced composite

  9. Wood thermoplastic composites

    Science.gov (United States)

    Daniel F. Caulfield; Craig Clemons; Roger M. Rowell

    2010-01-01

    The wood industry can expand into new sustainable markets with the formation of a new class of composites with the marriage of the wood industry and the plastics industry. The wood component, usually a flour or fiber, is combined with a thermoplastic to form an extrudable, injectable or thermoformable composite that can be used in many non-structural applications....

  10. Students design composite bridges

    NARCIS (Netherlands)

    Stark, J.W.B.; Galjaard, J.C.; Brekelmans, J.W.P.M.

    1999-01-01

    The paper gives an overview of recent research on steel-concrete composite bridge design by students of Delft University of Technology doing their master's thesis. Primary objective of this research was to find possibilities for application of steel-concrete composite bridges in the Netherlands,

  11. Superconducting composites materials. Materiaux composites supraconducteurs

    Energy Technology Data Exchange (ETDEWEB)

    Kerjouan, P; Boterel, F; Lostec, J; Bertot, J P; Haussonne, J M [Centre National d' Etudes des Telecommunications (CNET), 22 - Lannion (FR)

    1991-11-01

    The new superconductor materials with a high critical current own a large importance as well in the electronic components or in the electrotechnical devices fields. The deposit of such materials with the thick films technology is to be more and more developed in the years to come. Therefore, we tried to realize such thick films screen printed on alumina, and composed mainly of the YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} material. We first realized a composite material glass/YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}, by analogy with the classical screen-printed inks where the glass ensures the bonding with the substrate. We thus realized different materials by using some different classes of glass. These materials owned a superconducting transition close to the one of the pure YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} material. We made a slurry with the most significant composite materials and binders, and screen-printed them on an alumina substrate preliminary or not coated with a diffusion barrier layer. After firing, we studied the thick films adhesion, the alumina/glass/composite material interfaces, and their superconducting properties. 8 refs.; 14 figs.; 9 tabs.

  12. Composite operators in QCD

    International Nuclear Information System (INIS)

    Sonoda, Hidenori

    1992-01-01

    We give a formula for the derivatives of a correlation function of composite operators with respect to the parameters (i.e. the strong fine structure constant and the quark mass) of QCD in four- dimensional euclidean space. The formula is given as spatial integration of the operator conjugate to a parameter. The operator product of a composite operator and a conjugate operator has an unintegrable part, and the formula requires divergent subtractions. By imposing consistency conditions we drive a relation between the anomalous dimensions of the composite operators and the unintegrable part of the operator product coefficients. (orig.)

  13. Electrically conductive composite material

    Science.gov (United States)

    Clough, Roger L.; Sylwester, Alan P.

    1989-01-01

    An electrically conductive composite material is disclosed which comprises a conductive open-celled, low density, microcellular carbon foam filled with a non-conductive polymer or resin. The composite material is prepared in a two-step process consisting of first preparing the microcellular carbon foam from a carbonizable polymer or copolymer using a phase separation process, then filling the carbon foam with the desired non-conductive polymer or resin. The electrically conductive composites of the present invention has a uniform and consistant pattern of filler distribution, and as a result is superior over prior art materials when used in battery components, electrodes, and the like.

  14. Nanocellulose electroconductive composites

    Science.gov (United States)

    Shi, Zhijun; Phillips, Glyn O.; Yang, Guang

    2013-03-01

    Cellulose-based electroconductive composites can be prepared by combining conducting electroactive materials with hydrophilic biocompatible cellulose. Inorganic nanoparticles, such as metal ions and oxides, carbon nanotubes, graphene and graphene oxide, conducting polymers, and ionic liquids (through doping, blending or coating) can be introduced into the cellulose matrix. Such composites can form a biocompatible interface for microelectronic devices, and provide a biocompatible matrix or scaffold for electrically stimulated drug release devices, implantable biosensors, and neuronal prostheses. Here the benefits of combining conventional and bacterial cellulose with these electroactive composites are described and future applications are considered.

  15. Composite Technologies for Exploration (CTE)

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA lacks experience with large scale (8.4m diameter) composite joints and joining of composites has been called the Achilles heel of composite structures, they...

  16. Little composite dark matter.

    Science.gov (United States)

    Balkin, Reuven; Perez, Gilad; Weiler, Andreas

    2018-01-01

    We examine the dark matter phenomenology of a composite electroweak singlet state. This singlet belongs to the Goldstone sector of a well-motivated extension of the Littlest Higgs with T -parity. A viable parameter space, consistent with the observed dark matter relic abundance as well as with the various collider, electroweak precision and dark matter direct detection experimental constraints is found for this scenario. T -parity implies a rich LHC phenomenology, which forms an interesting interplay between conventional natural SUSY type of signals involving third generation quarks and missing energy, from stop-like particle production and decay, and composite Higgs type of signals involving third generation quarks associated with Higgs and electroweak gauge boson, from vector-like top-partners production and decay. The composite features of the dark matter phenomenology allows the composite singlet to produce the correct relic abundance while interacting weakly with the Higgs via the usual Higgs portal coupling [Formula: see text], thus evading direct detection.

  17. Partially composite Higgs models

    DEFF Research Database (Denmark)

    Alanne, Tommi; Buarque Franzosi, Diogo; Frandsen, Mads T.

    2018-01-01

    We study the phenomenology of partially composite-Higgs models where electroweak symmetry breaking is dynamically induced, and the Higgs is a mixture of a composite and an elementary state. The models considered have explicit realizations in terms of gauge-Yukawa theories with new strongly...... interacting fermions coupled to elementary scalars and allow for a very SM-like Higgs state. We study constraints on their parameter spaces from vacuum stability and perturbativity as well as from LHC results and find that requiring vacuum stability up to the compositeness scale already imposes relevant...... constraints. A small part of parameter space around the classically conformal limit is stable up to the Planck scale. This is however already strongly disfavored by LHC results. in different limits, the models realize both (partially) composite-Higgs and (bosonic) technicolor models and a dynamical extension...

  18. Fundamental partial compositeness

    CERN Document Server

    Sannino, Francesco

    2016-11-07

    We construct renormalizable Standard Model extensions, valid up to the Planck scale, that give a composite Higgs from a new fundamental strong force acting on fermions and scalars. Yukawa interactions of these particles with Standard Model fermions realize the partial compositeness scenario. Successful models exist because gauge quantum numbers of Standard Model fermions admit a minimal enough 'square root'. Furthermore, right-handed SM fermions have an SU(2)$_R$-like structure, yielding a custodially-protected composite Higgs. Baryon and lepton numbers arise accidentally. Standard Model fermions acquire mass at tree level, while the Higgs potential and flavor violations are generated by quantum corrections. We further discuss accidental symmetries and other dynamical features stemming from the new strongly interacting scalars. If the same phenomenology can be obtained from models without our elementary scalars, they would reappear as composite states.

  19. Compositeness: The supercollider frontier

    International Nuclear Information System (INIS)

    Peccei, R.D.

    1984-01-01

    In this report I discuss some of the reasons which point towards this 'nearby compositeness', and examine some of the physical phenomena that are connected with substructure which could be explored at a Supercollider. (orig./HSI)

  20. Proximate composition, bread

    African Journals Online (AJOL)

    Toshiba

    2011-12-07

    Dec 7, 2011 ... indicate that carbohydrate, crude fiber, and ash contents of the .... percentage (% EE) was determined using Soxhlet system HT-extraction technique ..... composite bread and effect of label information on acceptance and ...

  1. Fundamental partial compositeness

    International Nuclear Information System (INIS)

    Sannino, Francesco; Strumia, Alessandro; Tesi, Andrea; Vigiani, Elena

    2016-01-01

    We construct renormalizable Standard Model extensions, valid up to the Planck scale, that give a composite Higgs from a new fundamental strong force acting on fermions and scalars. Yukawa interactions of these particles with Standard Model fermions realize the partial compositeness scenario. Under certain assumptions on the dynamics of the scalars, successful models exist because gauge quantum numbers of Standard Model fermions admit a minimal enough ‘square root’. Furthermore, right-handed SM fermions have an SU(2)_R-like structure, yielding a custodially-protected composite Higgs. Baryon and lepton numbers arise accidentally. Standard Model fermions acquire mass at tree level, while the Higgs potential and flavor violations are generated by quantum corrections. We further discuss accidental symmetries and other dynamical features stemming from the new strongly interacting scalars. If the same phenomenology can be obtained from models without our elementary scalars, they would reappear as composite states.

  2. Shakedown analysis of composites

    CERN Document Server

    Weichert, D; Schwabe, F

    1999-01-01

    One of the advantages of composite materials compared to conventional materials stems from the different mechanical characteristics of each component of a composite. This may be used to design materials for specific technological $9 purposes, where in some sense controversial material properties are required. As example one may quote metal- matrix-composites (MMCs) exhibiting at the same time high hardness and fracture toughness. To predict failure of this type $9 of materials, it is important to understand the complex processes on the microstructural level leading to failure, including in particular inelastic effects, and to link them to the macroscopic material properties. In this paper, $9 failure of metal-matrix-composites under variables loads due to accumulated plastic deformations is investigated. For this, shakedown-analysis is carried out on the micro-level. Then, by use of the technique of homogenisation, the $9 results are linked to the overall material properties on the macro- level. The methodolo...

  3. REINFORCED COMPOSITE PANEL

    DEFF Research Database (Denmark)

    2003-01-01

    A composite panel having front and back faces, the panel comprising facing reinforcement, backing reinforcement and matrix material binding to the facing and backing reinforcements, the facing and backing reinforcements each independently comprising one or more reinforcing sheets, the facing rein...... by matrix material, the facing and backing reinforcements being interconnected to resist out-of-plane relative movement. The reinforced composite panel is useful as a barrier element for shielding structures, equipment and personnel from blast and/or ballistic impact damage....

  4. Synthetic staggered architecture composites

    International Nuclear Information System (INIS)

    Dutta, Abhishek; Tekalur, Srinivasan Arjun

    2013-01-01

    Highlights: ► Composite design inspired by nature. ► Tuning microstructure via changing ceramic content and aspect ratio. ► Experimental display of structure–property correlationship in synthetic composites. - Abstract: Structural biocomposites (for example, nacre in seashells, bone, etc.) are designed according to the functional role they are delegated for. For instance, bone is primarily designed for withstanding time-dependent loading (for example, withstanding stresses while running, jumping, accidental fall) and hence the microstructure is designed primarily from enhanced toughness and moderate stiffness point of view. On the contrary, seashells (which lie in the abyss of oceans) apart from providing defense to the organism (it is hosting) against predatory attacks, are subjected to static loading (for example, enormous hydrostatic pressure). Hence, emphasis on the shell structure evolution is directed primarily towards providing enhanced stiffness. In order to conform between stiffness and toughness, nature precisely employs a staggered arrangement of inorganic bricks in a biopolymer matrix (at its most elementary level of architecture). Aspect ratio and content of ceramic bricks are meticulously used by nature to synthesize composites having varying degrees of stiffness, strength and toughness. Such an amazing capability of structure–property correlationship has rarely been demonstrated in synthetic composites. Therefore, in order to better understand the mechanical behavior of synthetic staggered composites, the problem becomes two-pronged: (a) synthesize composites with varying brick size and contents and (b) experimental investigation of the material response. In this article, an attempt has been made to synthesize and characterize staggered ceramic–polymer composites having varying aspect ratio and ceramic content using freeze-casting technique. This will in-turn help us in custom-design manufacture of hybrid bio-inspired composite materials

  5. Magnetoelectricity in composites

    CERN Document Server

    Bichurin, Mirza

    2011-01-01

    Magnetoelectric composites, which simultaneously exhibit ferroelectricity and ferromagnetism, have recently stimulated a sharply increasing number of research activities for their scientific interest and significant technological promise in the novel multifunctional devices. Natural single-phase compounds are rare, and their magnetoelectric responses are either relatively weak or occurs at temperatures too low for practical applications. In contrast, composites, which incorporate both ferroelectric and ferri-/ferromagnetic phases, typically yield giant magnetoelectric coupling response above r

  6. Low energy particle composition

    International Nuclear Information System (INIS)

    Gloeckler, G.

    1975-01-01

    More than 50 papers presented at this Conference dealt with the composition of low energy particles. The topics can be divided roughly into two broad categories. The first is the study of the energy spectra and composition of the steady or 'quiet-time' particle flux, whose origin is at this time unknown. The second category includes the study of particles and photons which are associated with solar flares or active regions on the sun. (orig.) [de

  7. Symbiotic Composition and Evolvability

    OpenAIRE

    Watson, Richard A.; Pollack, Jordan B.

    2001-01-01

    Several of the Major Transitions in natural evolution, such as the symbiogenic origin of eukaryotes from prokaryotes, share the feature that existing entities became the components of composite entities at a higher level of organisation. This composition of pre-adapted extant entities into a new whole is a fundamentally different source of variation from the gradual accumulation of small random variations, and it has some interesting consequences for issues of evolvability. In this paper we p...

  8. Composite weak bosons

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, M.

    1988-04-01

    Dynamical mechanism of composite W and Z is studied in a 1/N field theory model with four-fermion interactions in which global weak SU(2) symmetry is broken explicitly by electromagnetic interaction. Issues involved in such a model are discussed in detail. Deviation from gauge coupling due to compositeness and higher order loop corrections are examined to show that this class of models are consistent not only theoretically but also experimentally.

  9. Continuous composite riser

    Energy Technology Data Exchange (ETDEWEB)

    Slagsvold, L. [ABB Offshore Systems (Norway)

    2002-12-01

    The industry is now looking at developing reserves in waters depths of up to 3000 m (10000 ft). When moving into deeper waters the un-bonded flexible riser becomes very heavy and introduces large hang-off forces on the vessel. We are therefore investigating riser concepts incorporating new materials and with a simpler cross section that can be used for floating production. Advanced composite materials have properties such as, low weight, high strength, good durability and very good fatigue performance. Composite materials are slowly being exploited in the oil industry; they are being prototype tested for drilling risers and small diameter lines. Part of the process for the industry to accept larger diameter production risers made out of composite materials is to understand both the advantages and limitations. A new continuous composite riser system is being developed which capitalizes on the technical benefits of this material while addressing the known constraints. The fully bonded riser is being developed for ultra deep waters and its' characteristics include high temperature (160 deg C), high pressure (500 barg min), light weight, chemical resistant, good insulation, excellent fatigue characteristics and installation by reeling. The concept is based on the use of a thermoplastic liner together with a thermoplastic carbon fibre composite. This paper summarises the ongoing development, which has a goal to manufacture and qualify an 8'' riser, and includes all the steps in a production process from material qualification to the winding process and analytical modelling. (author)

  10. Nanostructured metal-polyaniline composites

    Science.gov (United States)

    Wang, Hsing-Lin; Li, Wenguang; Bailey, James A.; Gao, Yuan

    2010-08-31

    Metal-polyaniline (PANI) composites are provided together with a process of preparing such composites by an electrodeless process. The metal of the composite can have nanoscale structural features and the composites can be used in applications such as catalysis for hydrogenation reactions and for analytical detection methods employing SERS.

  11. Radiation curable coating compositions

    International Nuclear Information System (INIS)

    Jenkinson, R.D.; Carder, C.H.

    1979-01-01

    The present invention provides a low-toxicity diluent component for radiation curable coating compositions that contain an acrylyl or methacryly oligomer or resin component such as an acrylyl urethane oligomer. The low-toxicity diluent component of this invention is chosen from the group consisting of tetraethlorthosilicate and tetraethoxyethylorthosilicate. When the diluent component is used as described, benefits in addition to viscosity reduction, may be realized. Application characteristics of the uncured coatings composition, such as flowability, leveling, and smoothness are notably improved. Upon curing by exposure to actinic radiation, the coating composition forms a solid, non-tacky surface free of pits, fissures or other irregularities. While there is no readily apparent reactive mechanism by which the orthosilicate becomes chemically bonded to the cured coating, the presence of silicon in the cured coating has been confirmed by scanning electron microscopy. 12 drawing

  12. Composite quantum collision models

    Science.gov (United States)

    Lorenzo, Salvatore; Ciccarello, Francesco; Palma, G. Massimo

    2017-09-01

    A collision model (CM) is a framework to describe open quantum dynamics. In its memoryless version, it models the reservoir R as consisting of a large collection of elementary ancillas: the dynamics of the open system S results from successive collisions of S with the ancillas of R . Here, we present a general formulation of memoryless composite CMs, where S is partitioned into the very open system under study S coupled to one or more auxiliary systems {Si} . Their composite dynamics occurs through internal S -{Si} collisions interspersed with external ones involving {Si} and the reservoir R . We show that important known instances of quantum non-Markovian dynamics of S —such as the emission of an atom into a reservoir featuring a Lorentzian, or multi-Lorentzian, spectral density or a qubit subject to random telegraph noise—can be mapped on to such memoryless composite CMs.

  13. Strength of Fibrous Composites

    CERN Document Server

    Huang, Zheng-Ming

    2012-01-01

    "Strength of Fibrous Composites" addresses evaluation of the strength of a fibrous composite by using its constituent material properties and its fiber architecture parameters. Having gone through the book, a reader is able to predict the progressive failure behavior and ultimate strength of a fibrous laminate subjected to an arbitrary load condition in terms of the constituent fiber and matrix properties, as well as fiber geometric parameters. The book is useful to researchers and engineers working on design and analysis for composite materials. Dr. Zheng-Ming Huang is a professor at the School of Aerospace Engineering & Applied Mechanics, Tongji University, China. Mr. Ye-Xin Zhou is a PhD candidate at the Department of Mechanical Engineering, the University of Hong Kong, China.

  14. Radiation polymerizable compositions

    International Nuclear Information System (INIS)

    Stvan, O.J.; Brodie, M.G.

    1978-01-01

    This invention relates to radiation polymerizable compositions particularly useful in the preparation of printing inks and to a method of preparing said radiation polymerizable compositions which comprises (1) a condensation product with (2) up to about 90% by weight thereof of at least one ethylenically unsaturated monomer and (3) up to about 50% by weight thereof of at least one sensitizer. The condensation products are prepared by condensing at least one alkoxy-methyl aminotriazine or methylol aminotriazine with one or more polyols, e.g., raw caster oil and at least one hydroxy-alkyl acrylate. The polymerizable composition may be cured with radiation, e.g., light or electrons, to obtain coatings useful for a variety of purposes

  15. Sintering of composite

    International Nuclear Information System (INIS)

    Bordia, R.K.; Scherer, G.W.

    1988-01-01

    Several constitutive laws have been used in the literature to predict the response of sintering bodies under external and internal stress fields. These analyses are based on the assumptions of linear and isotropic behavior. The authors provide a critical examination of these equations and show that some of the available constitutive laws predict a negative Poisson's ratio. These laws have been used to analyze sintering of ceramic matrix composites with rigid inclusions and predict large values of the internal stresses and significant retardation of the densification of composites. Since a negative value of Poisson's ratio has never been observed in sinter - forging experiments, the authors conclude that either the stresses are small (as predicted by the constitutive laws with positive Poisson's ratio) or the basic assumption of linearity and isotropy used in all the analyses is incorrect. Finally, the authors discuss some phenomena that could be important in understanding the densification of ceramic matrix composites

  16. Ceramic Composite Thin Films

    Science.gov (United States)

    Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)

    2013-01-01

    A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

  17. Vertical Protocol Composition

    DEFF Research Database (Denmark)

    Groß, Thomas; Mödersheim, Sebastian Alexander

    2011-01-01

    The security of key exchange and secure channel protocols, such as TLS, has been studied intensively. However, only few works have considered what happens when the established keys are actually used—to run some protocol securely over the established “channel”. We call this a vertical protocol.......e., that the combination cannot introduce attacks that the individual protocols in isolation do not have. In this work, we prove a composability result in the symbolic model that allows for arbitrary vertical composition (including self-composition). It holds for protocols from any suite of channel and application...

  18. Thixotropic, radiation curable compositions

    International Nuclear Information System (INIS)

    Miller, L.S.

    1976-01-01

    A reactive metal oxide or metal hydroxide, such as ZnO, MgO, HgO or Ba(OH) 2 and acrylic or methacrylic acid are added to a liquid, hydrophobic, essentially solvent-free coating vehicle capable of being cured by high-energy radiation. The resulting coating composition, as compared to the vehicle alone, can be cured with lower radiation doses, is less susceptible to oxygen inhibition of curing with ionizing radiation and exhibits a thixotropic viscosity which prevents excessive penetration of the coating into porous substrates and contributes non-drip, low-flow characteristics to the composition

  19. Fundamental composite electroweak dynamics

    DEFF Research Database (Denmark)

    Arbey, Alexandre; Cacciapaglia, Giacomo; Cai, Haiying

    2017-01-01

    Using the recent joint results from the ATLAS and CMS collaborations on the Higgs boson, we determine the current status of composite electroweak dynamics models based on the expected scalar sector. Our analysis can be used as a minimal template for a wider class of models between the two limitin...... space at the effective Lagrangian level. We show that a wide class of models of fundamental composite electroweak dynamics are still compatible with the present constraints. The results are relevant for the ongoing and future searches at the Large Hadron Collider....

  20. Multifunctional materials and composites

    Science.gov (United States)

    Seo, Dong-Kyun; Jeon, Ki-Wan

    2017-08-22

    Forming multifunctional materials and composites thereof includes contacting a first material having a plurality of oxygen-containing functional groups with a chalcogenide compound, and initiating a chemical reaction between the first material and the chalcogenide compound, thereby replacing oxygen in some of the oxygen-containing functional groups with chalcogen from the chalcogen-containing compound to yield a second material having chalcogen-containing functional groups and oxygen-containing functional groups. The first material is a carbonaceous material or a macromolecular material. A product including the second material is collected and may be processed further to yield a modified product or a composite.

  1. Accelerated testing of composites

    Science.gov (United States)

    Papazian, H. A.

    1983-01-01

    It is shown that the Zhurkov method for testing the strength of solids can be applied to dynamic tension and to cyclic loading and provides a viable approach to accelerated testing of composites. Data from the literature are used to demonstrate a straightforward application of the method to dynamic tension of glass fiber and cyclic loading for glass/polymer, metal matrix, and graphite/epoxy composites. Zhurkov's equation can be used at relatively high loads to obtain failure times at any temperature of interest. By taking a few data points at one or two other temperatures the spectrum of failure times can be expanded to temperatures not easily accessible.

  2. Minimal Composite Inflation

    DEFF Research Database (Denmark)

    Channuie, Phongpichit; Jark Joergensen, Jakob; Sannino, Francesco

    2011-01-01

    We investigate models in which the inflaton emerges as a composite field of a four dimensional, strongly interacting and nonsupersymmetric gauge theory featuring purely fermionic matter. We show that it is possible to obtain successful inflation via non-minimal coupling to gravity, and that the u......We investigate models in which the inflaton emerges as a composite field of a four dimensional, strongly interacting and nonsupersymmetric gauge theory featuring purely fermionic matter. We show that it is possible to obtain successful inflation via non-minimal coupling to gravity...

  3. Volumetric composition of nanocomposites

    DEFF Research Database (Denmark)

    Madsen, Bo; Lilholt, Hans; Mannila, Juha

    2015-01-01

    is presented, using cellulose/epoxy and aluminosilicate/polylactate nanocomposites as case materials. The buoyancy method is used for the accurate measurements of materials density. The accuracy of the method is determined to be high, allowing the measured nanocomposite densities to be reported with 5...... significant figures. The plotting of the measured nanocomposite density as a function of the nanofibre weight content is shown to be a first good approach of assessing the porosity content of the materials. The known gravimetric composition of the nanocomposites is converted into a volumetric composition...

  4. Kevlar reinforced neoprene composites

    Science.gov (United States)

    Penn, B. G.; Daniels, J. G.; White, W. T.; Thompson, L. M.; Clemons, L. M.

    1985-01-01

    Kevlar/neoprene composites were prepared by two techniques. One method involved the fabrication of a composite from a rubber prepreg prepared by coating Kevlar with viscous neoprene solution and then allowing the solvent to evaporate (solution impregnation technique). The second method involved heating a stack of Kevlar/neoprene sheets at a temperature sufficient to cause polymer flow (melt flow technique). There was no significant difference in the breaking strength and percent elongation for samples obtained by the two methods; however the shear strength obtained for samples fabricated by the solution impregnation technique (275 psi) was significantly higher than that found for the melt flow fabricated samples (110 psi).

  5. Little composite dark matter

    Science.gov (United States)

    Balkin, Reuven; Perez, Gilad; Weiler, Andreas

    2018-02-01

    We examine the dark matter phenomenology of a composite electroweak singlet state. This singlet belongs to the Goldstone sector of a well-motivated extension of the Littlest Higgs with T-parity. A viable parameter space, consistent with the observed dark matter relic abundance as well as with the various collider, electroweak precision and dark matter direct detection experimental constraints is found for this scenario. T-parity implies a rich LHC phenomenology, which forms an interesting interplay between conventional natural SUSY type of signals involving third generation quarks and missing energy, from stop-like particle production and decay, and composite Higgs type of signals involving third generation quarks associated with Higgs and electroweak gauge boson, from vector-like top-partners production and decay. The composite features of the dark matter phenomenology allows the composite singlet to produce the correct relic abundance while interacting weakly with the Higgs via the usual Higgs portal coupling λ _{ {DM}}˜ O(1%), thus evading direct detection.

  6. (ethylene terephthalate) biomimetic composites

    Indian Academy of Sciences (India)

    In vitro bioactivity of the HAp/PEA-co-PET composites was studied by soaking in simulated .... 2.2d Characterization of cyclic oligomers: The C-OEA, ... GENESIS2000, EDAX) for microanalysis. ... Both spectra did not show the signal of end.

  7. Nocturne aquatique (musical composition)

    OpenAIRE

    Atkinson, Simon

    2015-01-01

    19 minutes duration; original performance version two stereo stems. Performance materials available from the composer. A musical composition, commissioned by Radio France/INA-GRM, world premiere given at Auditorium Saint-Germain, Paris, 24th January 2015 as part of the Akousma Festival programme.

  8. Flame retardant compositions

    International Nuclear Information System (INIS)

    Biggs, J.W.; Maringer, M.F.

    1982-01-01

    Radiation crosslinked compositions containing copolymers of ethylene and vinyl ester of a (meth) acrylate, a hydrated inorganic filler, a higher concentration of silane than employed heretofore and a lubricant of lauric acid and ethylene-bis-stearamide exhibit physical strength properties substantially similar to a chemically crosslinked counterpart. (author)

  9. Wood Composite Adhesives

    Science.gov (United States)

    Gomez-Bueso, Jose; Haupt, Robert

    The global environment, in which phenolic resins are being used for wood composite manufacture, has changed significantly during the last decade. This chapter reviews trends that are driving the use and consumption of phenolic resins around the world. The review begins with recent data on volume usage and regional trends, followed by an analysis of factors affecting global markets. In a section on environmental factors, the impact of recent formaldehyde emission regulations is discussed. The section on economics introduces wood composite production as it relates to the available adhesive systems, with special emphasis on the technical requirement to improve phenolic reactivity. Advances in composite process technology are introduced, especially in regard to the increased demands the improvements place upon adhesive system performance. The specific requirements for the various wood composite families are considered in the context of adhesive performance needs. The results of research into current chemistries are discussed, with a review of recent findings regarding the mechanisms of phenolic condensation and acceleration. Also, the work regarding alternate natural materials, such as carbohydrates, lignins, tannins, and proteinaceous materials, is presented. Finally, new developments in alternative adhesive technologies are reported.

  10. Future flare compositions

    NARCIS (Netherlands)

    Lingen, J.L.N. van; Meuken, D.; Hackspik, M.M.; Mäkeläinen, T.; Weiser, V.; Poulson, G.W.

    2014-01-01

    This poster describes the work done within the Category B joint research project under the European Defence Agency (EDA) on Future Flare Compositions [1]. Contributing members were Finland, Germany, United Kingdom and the Netherlands. The program was aimed to identify the technology gaps that apply

  11. Composite material dosimeters

    Science.gov (United States)

    Miller, Steven D.

    1996-01-01

    The present invention is a composite material containing a mix of dosimeter material powder and a polymer powder wherein the polymer is transparent to the photon emission of the dosimeter material powder. By mixing dosimeter material powder with polymer powder, less dosimeter material is needed compared to a monolithic dosimeter material chip. Interrogation is done with excitation by visible light.

  12. Underwater Scene Composition

    Science.gov (United States)

    Kim, Nanyoung

    2009-01-01

    In this article, the author describes an underwater scene composition for elementary-education majors. This project deals with watercolor with crayon or oil-pastel resist (medium); the beauty of nature represented by fish in the underwater scene (theme); texture and pattern (design elements); drawing simple forms (drawing skill); and composition…

  13. Template Composite Dark Matter

    DEFF Research Database (Denmark)

    Drach, Vincent; Hietanen, Ari; Pica, Claudio

    2015-01-01

    We present a non perturbative study of SU(2) gauge theory with two fundamental Dirac flavours. We discuss how the model can be used as a template for composite Dark Matter (DM). We estimate one particular interaction of the DM candidate with the Standard Model : the interaction through photon...

  14. The Composite Insertion Electrode

    DEFF Research Database (Denmark)

    Atlung, Sven; Zachau-Christiansen, Birgit; West, Keld

    1984-01-01

    The specific energy obtainable by discharge of porous insertion electrodes is limited by electrolyte depletion in thepores. This can be overcome using a solid ion conductor as electrolyte. The term "composite" is used to distinguishthese electrodes from porous electrodes with liquid electrolyte...

  15. Little composite dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Balkin, Reuven; Weiler, Andreas [Technische Universitaet Muenchen, First Physik-Department, Garching (Germany); Perez, Gilad [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel)

    2018-02-15

    We examine the dark matter phenomenology of a composite electroweak singlet state. This singlet belongs to the Goldstone sector of a well-motivated extension of the Littlest Higgs with T-parity. A viable parameter space, consistent with the observed dark matter relic abundance as well as with the various collider, electroweak precision and dark matter direct detection experimental constraints is found for this scenario. T-parity implies a rich LHC phenomenology, which forms an interesting interplay between conventional natural SUSY type of signals involving third generation quarks and missing energy, from stop-like particle production and decay, and composite Higgs type of signals involving third generation quarks associated with Higgs and electroweak gauge boson, from vector-like top-partners production and decay. The composite features of the dark matter phenomenology allows the composite singlet to produce the correct relic abundance while interacting weakly with the Higgs via the usual Higgs portal coupling λ{sub DM} ∝ O(1%), thus evading direct detection. (orig.)

  16. Composite lamination method

    Science.gov (United States)

    Dickerson, G. E. (Inventor)

    1977-01-01

    A process was developed for preparing relatively thick composite laminate structure wherein thin layers of prepreg tapes are assembled, these thin layers are cut into strips that are partially cured, and stacked into the desired thickness with uncured prepreg disposed between each layer of strips. The formed laminate is finally cured and thereafter machined to the desired final dimensions.

  17. Compositional data types

    DEFF Research Database (Denmark)

    Bahr, Patrick; Hvitved, Tom

    2011-01-01

    -cut fusion style deforestation which yields considerable speedups. We demonstrate our framework in the setting of compiler construction, and moreover, we compare compositional data types with generic programming techniques and show that both are comparable in run-time performance and expressivity while our...

  18. Conductive polymer composition

    NARCIS (Netherlands)

    2010-01-01

    The present invention relates to a process for the preparation of a conductive polymer composition comprising graphene and the articles obtained by this process. The process comprises the following steps: A) contacting graphite oxide in an aqueous medium with a water-soluble or dispersible

  19. Space and composition

    DEFF Research Database (Denmark)

    Kjølner, Torunn

    2005-01-01

    The article takes concept art and Deleuze and Guattari's understanding of concept as  references for thinking theatre as an art form defined as a composition of elements in time and space. It offers a discussion of three different kinds of spatial approaches to theatre making and  a discussion...

  20. Composite Dark Sectors

    International Nuclear Information System (INIS)

    Carmona, Adrian

    2015-06-01

    We introduce a new paradigm in Composite Dark Sectors, where the full Standard Model (including the Higgs boson) is extended with a strongly-interacting composite sector with global symmetry group G spontaneously broken to H is contained in G. We show that, under well-motivated conditions, the lightest neutral pseudo Nambu-Goldstone bosons are natural dark matter candidates for they are protected by a parity symmetry not even broken in the electroweak phase. These models are characterized by only two free parameters, namely the typical coupling g D and the scale f D of the composite sector, and are therefore very predictive. We consider in detail two minimal scenarios, SU(3)/[SU(2) x U(1)] and [SU(2) 2 x U(1)]/[SU(2) x U(1)], which provide a dynamical realization of the Inert Doublet and Triplet models, respectively. We show that the radiatively-induced potential can be computed in a five-dimensional description with modified boundary conditions with respect to Composite Higgs models. Finally, the dark matter candidates are shown to be compatible, in a large region of the parameter space, with current bounds from dark matter searches as well as electroweak and collider constraints on new resonances.

  1. REST based service composition

    DEFF Research Database (Denmark)

    Grönvall, Erik; Ingstrup, Mads; Pløger, Morten

    2011-01-01

    This paper presents an ongoing work developing and testing a Service Composition framework based upon the REST architecture named SECREST. A minimalistic approach have been favored instead of a creating a complete infrastructure. One focus has been on the system's interaction model. Indeed, an aim...

  2. Carbon composites composites with carbon fibers, nanofibers, and nanotubes

    CERN Document Server

    Chung, Deborah D L

    2017-01-01

    Carbon Composites: Composites with Carbon Fibers, Nanofibers, and Nanotubes, Second Edition, provides the reader with information on a wide range of carbon fiber composites, including polymer-matrix, metal-matrix, carbon-matrix, ceramic-matrix and cement-matrix composites. In contrast to other books on composites, this work emphasizes materials rather than mechanics. This emphasis reflects the key role of materials science and engineering in the development of composite materials. The applications focus of the book covers both the developing range of structural applications for carbon fiber composites, including military and civil aircraft, automobiles and construction, and non-structural applications, including electromagnetic shielding, sensing/monitoring, vibration damping, energy storage, energy generation, and deicing. In addition to these new application areas, new material in this updated edition includes coverage of cement-matrix composites, carbon nanofibers, carbon matrix precursors, fiber surface ...

  3. Uncharged positive electrode composition

    Science.gov (United States)

    Kaun, Thomas D.; Vissers, Donald R.; Shimotake, Hiroshi

    1977-03-08

    An uncharged positive-electrode composition contains particulate lithium sulfide, another alkali metal or alkaline earth metal compound other than sulfide, e.g., lithium carbide, and a transition metal powder. The composition along with a binder, such as electrolytic salt or a thermosetting resin is applied onto an electrically conductive substrate to form a plaque. The plaque is assembled as a positive electrode within an electrochemical cell opposite to a negative electrode containing a material such as aluminum or silicon for alloying with lithium. During charging, lithium alloy is formed within the negative electrode and transition metal sulfide such as iron sulfide is produced within the positive electrode. Excess negative electrode capacity over that from the transition metal sulfide is provided due to the electrochemical reaction of the other than sulfide alkali metal or alkaline earth metal compound.

  4. Micromechanics of Composite Materials

    CERN Document Server

    Dvorak, George

    2013-01-01

    This book presents a broad exposition of analytical and numerical methods for modeling composite materials, laminates, polycrystals and other heterogeneous solids, with emphasis on connections between material properties and responses on several length scales, ranging from the nano and microscales to the macroscale. Many new results and methods developed by the author are incorporated into a rich fabric of the subject, which has been explored by several researchers over the last 40 years.   The first  part of the book reviews anisotropic elasticity theory, and then it describes the frequently used procedures and theorems for bounding and estimating overall properties, local fields and energy changes in elastic inhomogeneities, heterogeneous media, fiber composites and functionally graded materials.  Those are caused by mechanical loads and by phase eigenstrains, such as thermal, transformation and inelastic strains, and also by cavities and cracks.    Worked examples show that the eigendeformations may...

  5. Commercial aircraft composite technology

    CERN Document Server

    Breuer, Ulf Paul

    2016-01-01

    This book is based on lectures held at the faculty of mechanical engineering at the Technical University of Kaiserslautern. The focus is on the central theme of societies overall aircraft requirements to specific material requirements and highlights the most important advantages and challenges of carbon fiber reinforced plastics (CFRP) compared to conventional materials. As it is fundamental to decide on the right material at the right place early on the main activities and milestones of the development and certification process and the systematic of defining clear requirements are discussed. The process of material qualification - verifying material requirements is explained in detail. All state-of-the-art composite manufacturing technologies are described, including changes and complemented by examples, and their improvement potential for future applications is discussed. Tangible case studies of high lift and wing structures emphasize the specific advantages and challenges of composite technology. Finally,...

  6. Composite carbon foam electrode

    Science.gov (United States)

    Mayer, Steven T.; Pekala, Richard W.; Kaschmitter, James L.

    1997-01-01

    Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivty and power to system energy.

  7. Kevlar reinforced neoprene composites

    International Nuclear Information System (INIS)

    Penn, B.G.; Daniels, J.G.; White, W.T.; Thompson, L.M.; Clemons, L.M.

    1985-01-01

    Kevlar/neoprene composites were prepared by two techniques. One method involved the fabrication of a composite from a rubber prepreg prepared by coating kevlar with viscous neoprene solution and then allowing the solvent to evaporate (solution impregnation technique). The second method involved heating a stack of kevlar/neoprene sheets at a temperature sufficient to cause polymer flow (melt flow technique). There was no significant difference in the breaking strength and percent elongation for samples obtained by the two methods; however the shear strength obtained for samples fabricated by the solution impregnation technique (275 psi) was significantly higher than that found for the melt flow fabricated samples (110 psi). 1 reference, 2 tables

  8. Natural rubber: leather composites

    Directory of Open Access Journals (Sweden)

    K. Ravichandran

    2005-06-01

    Full Text Available Leather is a fibrous protein consisting of collagen in a three dimensionally crosslinked network. Chrome tanning of leather improves the appearance of leather but at the same time emits both solid and liquid chrome leather wastes. Scrap rubber recycling using untreated and neutralized leather fibrous particles in natural rubber has been studied. Vulcanization, mechanical, morphological and swelling properties of the natural rubber - scrap rubber composites containing neutralized leather have been discussed. Use of chrome leather particles has been found to improve the consumption of scrap rubber powder in natural rubber formulations. Polymer composites based on leather wastes as fillers are reported to be useful for many applications such as in construction materials, automobile interior moldings, heat and sound insulating boards, shoe soles, flooring materials and moldings with good anti-static properties, air permeability and good appearances.

  9. GPS Composite Clock Analysis

    OpenAIRE

    Wright, James R.

    2008-01-01

    The GPS composite clock defines GPS time, the timescale used today in GPS operations. GPS time is illuminated by examination of its role in the complete estimation and control problem relative to UTC/TAI. The phase of each GPS clock is unobservable from GPS pseudorange measurements, and the mean phase of the GPS clock ensemble (GPS time) is unobservable. A new and useful observability definition is presented, together with new observability theorems, to demonstrate explicitly that GPS time is...

  10. Free radical explosive composition

    Science.gov (United States)

    Walker, Franklin E.; Wasley, Richard J.

    1979-01-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a getter additive comprising a compound or mixture of compounds capable of capturing or deactivating free radicals or ions under mechanical or electrical shock conditions and which is not an explosive. Exemplary getter additives are isocyanates, olefins and iodine.

  11. Compositeness at LEP

    International Nuclear Information System (INIS)

    Bardadin-Otwinowska, M.

    1992-01-01

    Searches for compositeness made by four LEP collaborations are reported. Limits are set on excited fermion masses and couplings. A limit on the branching ratio Z→γγγ is determined. Four-fermion and two-fermion, two-boson contact terms are studied in the reactions e + e - →l + l - and e + e - →γγ respectively and limits are obtained on the energy scale of a new interaction

  12. Biotechnology and Composite Materials

    Science.gov (United States)

    1993-04-01

    means. Silk made from the caterpillar, Bombyx mori , has outstanding mechanical and good thermal properties. The Bombyx mori synthesises the components of...Silk Proteins for Composite Fibers 185 In natural systems, the two c=nm=n sources of silks are the dch!sticated silkworm, mori , and the orb weaving...unit cell remain parallel to their original orientation during deformation. This prevents the formation of any voids or gaps in the model. Using the

  13. Iron aluminide composites

    International Nuclear Information System (INIS)

    Schneibel, J.H.

    1999-01-01

    Iron aluminides with the B2 structure are highly oxidation and corrosion resistant. They are thermodynamically compatible with a wide range of ceramics such as TiC, WC, TiB 2 , and ZrB 2 . In addition, liquid iron aluminides wet these ceramics very well. Therefore, FeAl/ceramic composites may be produced by techniques such as liquid phase sintering of powder mixtures, or pressureless melt infiltration of ceramic powders with liquid FeAl. These techniques, the resulting microstructures, and their advantages as well as limitations are described. Iron aluminide composites can be very strong. Room temperature flexure strengths as high as 1.8 GPa have been observed for FeAl/WC. Substantial gains in strength of elevated temperatures (1,073 K) have also been demonstrated. Above 40 vol.% WC the room temperature flexure strength becomes flaw-limited. This is thought to be due to processing flaws and limited interfacial strength. The fracture toughness of FeAl/WC is unexpectedly high and follows a rule of mixtures. Interestingly, sufficiently thin (<1 microm) FeAl ligaments between adjacent WC particles fracture not by cleavage, but in a ductile manner. For these thin ligaments the dislocation pile-ups formed during deformation are not long enough to nucleate cleavage fracture, and their fracture mode is therefore ductile. For several reasons, this brittle-to-ductile size transition does not improve the fracture toughness of the composites significantly. However, since no cleavage cracks are nucleated in sufficiently thin FeAl ligaments, slow crack growth due to ambient water vapor does not occur. Therefore, as compared to monolithic iron aluminides, environmental embrittlement is dramatically reduced in iron aluminide composites

  14. Edge effects in composites

    International Nuclear Information System (INIS)

    Guz, A.N.; Kokhanenko, Yu.V.

    1995-01-01

    In the present article we survey papers on edge effects investigated by the rigorous approach. We interpret edge effects as stressed states created in a composite as a result of zones in which the stresses exhibit a rapidly changing behavior in comparison with the slow variation of the stresses outside such zones. Here the range of the edge effect is defined as the distance from the point of its inception to the boundary of the edge zone in a given direction. The transition of the stresses to the slowly varying state is determined within prescribed error limits. The size and configuration of the edge zone depends on the tolerated error. Clearly, the main difficulty associated with the rigorous approach is finding solutions of the elasticity problems. The finite-difference approach is suggested for the approximate solution of these problems. In light of the comparative time consumption of the finite-difference approach, it is best directed at certain classes of problems rather than at particular individual problems. Not too many papers on the investigation of edge effects by the rigorous approach have been published to date. Below, following in their footsteps, we formulate edge effect problems in composites, determine classes of problems, and investigate edge effects in composite materials and structural elements using them in Cartesian (planar and three-dimensional problems) and cylindrical (axisymmetric problems) coordinate frames. We note that the division of approaches to the study of edge effects into qualitative (nonrigorous) and quantitative (rigorous) reflects the authors own point of view. Of course, other schemes of classification of the approaches to the investigation of the regions of rapidly varying states in composites are possible

  15. Composite airfoil assembly

    Science.gov (United States)

    Garcia-Crespo, Andres Jose

    2015-03-03

    A composite blade assembly for mounting on a turbine wheel includes a ceramic airfoil and an airfoil platform. The ceramic airfoil is formed with an airfoil portion, a blade shank portion and a blade dovetail tang. The metal platform includes a platform shank and a radially inner platform dovetail. The ceramic airfoil is captured within the metal platform, such that in use, the ceramic airfoil is held within the turbine wheel independent of the metal platform.

  16. Computing Equilibrium Chemical Compositions

    Science.gov (United States)

    Mcbride, Bonnie J.; Gordon, Sanford

    1995-01-01

    Chemical Equilibrium With Transport Properties, 1993 (CET93) computer program provides data on chemical-equilibrium compositions. Aids calculation of thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93/PC is version of CET93 specifically designed to run within 640K memory limit of MS-DOS operating system. CET93/PC written in FORTRAN.

  17. Natural rubber: leather composites

    OpenAIRE

    Ravichandran,K.; Natchimuthu,N.

    2005-01-01

    Leather is a fibrous protein consisting of collagen in a three dimensionally crosslinked network. Chrome tanning of leather improves the appearance of leather but at the same time emits both solid and liquid chrome leather wastes. Scrap rubber recycling using untreated and neutralized leather fibrous particles in natural rubber has been studied. Vulcanization, mechanical, morphological and swelling properties of the natural rubber - scrap rubber composites containing neutralized leather have ...

  18. Teaching Compositionality to CNNs

    OpenAIRE

    Stone, Austin; Wang, Huayan; Stark, Michael; Liu, Yi; Phoenix, D. Scott; George, Dileep

    2017-01-01

    Convolutional neural networks (CNNs) have shown great success in computer vision, approaching human-level performance when trained for specific tasks via application-specific loss functions. In this paper, we propose a method for augmenting and training CNNs so that their learned features are compositional. It encourages networks to form representations that disentangle objects from their surroundings and from each other, thereby promoting better generalization. Our method is agnostic to the ...

  19. Composite Repair System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — GTL has developed an innovative composite repair methodology known as the Composite Repair System (CRS). In this phase I effort, CRS is being developed for the...

  20. Carbon/carbon composite materials

    International Nuclear Information System (INIS)

    Thebault, J.; Orly, P.

    2006-01-01

    Carbon/carbon composites are singular materials from their components, their manufacturing process as well as their characteristics. This paper gives a global overview of these particularities and applications which make them now daily used composites. (authors)

  1. Body composition and wages.

    Science.gov (United States)

    Wada, Roy; Tekin, Erdal

    2010-07-01

    This paper examines the relationship between body composition and wages in the United States. We develop measures of body composition--body fat (BF) and fat-free mass (FFM)--using data on bioelectrical impedance analysis (BIA) that are available in the National Health and Nutrition Examination Survey III and estimate wage models for respondents in the National Longitudinal Survey of Youth 1979. Previous research uses body size or BMI as measures of obesity despite a growing concern that they do not distinguish between body fat and fat-free body mass or adequately control for non-homogeneity inside the human body. Therefore, measures presented in this paper represent a useful alternative to BMI-based proxies of obesity. Our results indicate that BF is associated with decreased wages for both males and females among whites and blacks. We also present evidence suggesting that FFM is associated with increased wages. We show that these results are not the artifacts of unobserved heterogeneity. Finally, our findings are robust to numerous specification checks and to a large number of alternative BIA prediction equations from which the body composition measures are derived. 2010 Elsevier B.V. All rights reserved.

  2. Superconducting composites materials

    International Nuclear Information System (INIS)

    Kerjouan, P.; Boterel, F.; Lostec, J.; Bertot, J.P.; Haussonne, J.M.

    1991-01-01

    The new superconductor materials with a high critical current own a large importance as well in the electronic components or in the electrotechnical devices fields. The deposit of such materials with the thick films technology is to be more and more developed in the years to come. Therefore, we tried to realize such thick films screen printed on alumina, and composed mainly of the YBa 2 Cu 3 O 7-δ material. We first realized a composite material glass/YBa 2 Cu 3 O 7-δ , by analogy with the classical screen-printed inks where the glass ensures the bonding with the substrate. We thus realized different materials by using some different classes of glass. These materials owned a superconducting transition close to the one of the pure YBa 2 Cu 3 O 7-δ material. We made a slurry with the most significant composite materials and binders, and screen-printed them on an alumina substrate preliminary or not coated with a diffusion barrier layer. After firing, we studied the thick films adhesion, the alumina/glass/composite material interfaces, and their superconducting properties. 8 refs.; 14 figs.; 9 tabs [fr

  3. Exceptional composite dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Ballesteros, Guillermo [Universite Paris Saclay, CEA, CNRS, Institut de Physique Theorique, Gif-sur-Yvette (France); Carmona, Adrian [CERN, Theoretical Physics Department, Geneva (Switzerland); Chala, Mikael [Universitat de Valencia y IFIC, Universitat de Valencia-CSIC, Departament de Fisica Teorica, Burjassot, Valencia (Spain)

    2017-07-15

    We study the dark matter phenomenology of non-minimal composite Higgs models with SO(7) broken to the exceptional group G{sub 2}. In addition to the Higgs, three pseudo-Nambu-Goldstone bosons arise, one of which is electrically neutral. A parity symmetry is enough to ensure this resonance is stable. In fact, if the breaking of the Goldstone symmetry is driven by the fermion sector, this Z{sub 2} symmetry is automatically unbroken in the electroweak phase. In this case, the relic density, as well as the expected indirect, direct and collider signals are then uniquely determined by the value of the compositeness scale, f. Current experimental bounds allow one to account for a large fraction of the dark matter of the Universe if the dark matter particle is part of an electroweak triplet. The totality of the relic abundance can be accommodated if instead this particle is a composite singlet. In both cases, the scale f and the dark matter mass are of the order of a few TeV. (orig.)

  4. Composite wind turbine towers

    Energy Technology Data Exchange (ETDEWEB)

    Polyzois, D. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Civil Engineering

    2008-07-01

    This paper discussed experiments conducted to optimized the advanced composite materials such as fiberglass reinforced plastics (FRP) used to fabricate wind turbine towers. FRP materials are used in tubular steel, lattice, guyed, and reinforced concrete towers. The towers and turbine blades are transported in segments and assembled on-site, sometimes in offshore or remote locations.The FRP composites are used to build towers with a high strength-to-weight ratio as well as to provide resistance to chemical attacks and corrosion. Use of the materials has resulted in towers that do not require heavy installation equipment. Experimental programs were conducted to verify the structural behaviour of the tower structure's individual-scaled cells as well as to evaluate the performance of multi-cell assemblies. Joint assembly designs were optimized, and a filament winding machine was used to conduct the experimental study and to test individual cells. Failure mode analyses were conducted to determine local buckling and shear rupture. Tension, compression, and shear properties of the FRP materials were tested experimentally, and data from the test were then used to develop finite element models of the composite towers as well as to obtain load deflection curves and tip oscillation data. A case study of a 750 kW wind turbine in Churchill, Manitoba was used to test the design. tabs., figs.

  5. Historicized Composition and Creative Ethnomusicology

    Directory of Open Access Journals (Sweden)

    Dániel Péter Biró

    2013-07-01

    Full Text Available This paper investigates relationship between compositional and ethnomusicological research. The method of historicized composition developed out of my work as a chant scholar, as ongoing ethnomusicological research has had a profound influence on my compositional work. Understanding and underscoring historical and phenomenological relationships between music and language, the act of composition becomes a creative discovery of relationships between musical material and music history.

  6. Nanoporous metal-carbon composite

    Science.gov (United States)

    Worsley, Marcus A.; Satcher, Joe; Kucheyev, Sergei; Charnvanichborikarn, Supakit; Colvin, Jeffrey; Felter, Thomas; Kim, Sangil; Merrill, Matthew; Orme, Christine

    2017-12-19

    Described here is a metal-carbon composite, comprising (a) a porous three-dimensional scaffold comprising one or more of carbon nanotubes, graphene and graphene oxide, and (b) metal nanoparticles disposed on said porous scaffold, wherein the metal-carbon composite has a density of 1 g/cm.sup.3 or less, and wherein the metal nanoparticles account for 1 wt. % or more of the metal-carbon composite. Also described are methods for making the metal-carbon composite.

  7. An exotic composite vector boson

    International Nuclear Information System (INIS)

    Akama, Keiichi; Hattori, Takashi; Yasue, Masaki.

    1990-08-01

    An exotic composite vector boson, V, is introduced in two dynamical models of composite quarks, leptons, W and Z. One is based on four Fermi interactions, in which composite vector bosons are regarded as fermion-antifermion bound states and the other is based on the confining SU(2) L gauge model, in which they are given by scalar-antiscalar bound states. Both approaches describe the same effective interactions for the sector of composite quarks, leptons, W, Z, γ and V. (author)

  8. Composition: Fire-Music (1976)

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2010-01-01

    This is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them in full length...

  9. Composition: Game of Contrasts (1980)

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2010-01-01

    This is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound file will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them in full length...

  10. THE DIMENSIONS OF COMPOSITION ANNOTATION.

    Science.gov (United States)

    MCCOLLY, WILLIAM

    ENGLISH TEACHER ANNOTATIONS WERE STUDIED TO DETERMINE THE DIMENSIONS AND PROPERTIES OF THE ENTIRE SYSTEM FOR WRITING CORRECTIONS AND CRITICISMS ON COMPOSITIONS. FOUR SETS OF COMPOSITIONS WERE WRITTEN BY STUDENTS IN GRADES 9 THROUGH 13. TYPESCRIPTS OF THE COMPOSITIONS WERE ANNOTATED BY CLASSROOM ENGLISH TEACHERS. THEN, 32 ENGLISH TEACHERS JUDGED…

  11. Continuous carbon nanotube reinforced composites.

    Science.gov (United States)

    Ci, L; Suhr, J; Pushparaj, V; Zhang, X; Ajayan, P M

    2008-09-01

    Carbon nanotubes are considered short fibers, and polymer composites with nanotube fillers are always analogues of random, short fiber composites. The real structural carbon fiber composites, on the other hand, always contain carbon fiber reinforcements where fibers run continuously through the composite matrix. With the recent optimization in aligned nanotube growth, samples of nanotubes in macroscopic lengths have become available, and this allows the creation of composites that are similar to the continuous fiber composites with individual nanotubes running continuously through the composite body. This allows the proper utilization of the extreme high modulus and strength predicted for nanotubes in structural composites. Here, we fabricate such continuous nanotube polymer composites with continuous nanotube reinforcements and report that under compressive loadings, the nanotube composites can generate more than an order of magnitude improvement in the longitudinal modulus (up to 3,300%) as well as damping capability (up to 2,100%). It is also observed that composites with a random distribution of nanotubes of same length and similar filler fraction provide three times less effective reinforcement in composites.

  12. Composition: S.C.E

    DEFF Research Database (Denmark)

    2012-01-01

    S.C.E. is a large collection of open compositions to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". This work is licensed under a Creative Commons "by-nc" License. You may for non-commercial purposes use and distribute...

  13. Desensitization of metastable intermolecular composites

    Science.gov (United States)

    Busse, James R [South Fork, CO; Dye, Robert C [Los Alamos, NM; Foley, Timothy J [Los Alamos, NM; Higa, Kelvin T [Ridgecrest, CA; Jorgensen, Betty S [Jemez Springs, NM; Sanders, Victor E [White Rock, NM; Son, Steven F [Los Alamos, NM

    2011-04-26

    A method to substantially desensitize a metastable intermolecular composite material to electrostatic discharge and friction comprising mixing the composite material with an organic diluent and removing enough organic diluent from the mixture to form a mixture with a substantially putty-like consistency, as well as a concomitant method of recovering the metastable intermolecular composite material.

  14. Composition: Detours/Obstacles (2008)

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2010-01-01

    These are open compositions to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". This work is licensed under a Creative Commons "by-nc" License. You may for non-commercial purposes use and distribute it, performance...

  15. Materiaux composites supraconducteurs

    Science.gov (United States)

    Kerjouan, Philippe; Boterel, Florence; Lostec, Jean; Bertot, Jean-Paul; Haussonne, Jean-Marie

    1991-11-01

    The new superconductor materials with a high critical current own a large importance as well in the electronic components or in the electrotechnical devices fields. The deposit of such materials with the thick films technology is to be more and more developped in the years to come. Therefore, we tried to realize such thick films screen printed on alumina, and composed mainly of the YBa2CU3O{7-δ} material. We first realized a composite material glass/YBa2CU3O{7-δ}, by analogy with the classical screen-printed inks where the glass ensures the bonding with the substrate. We thus realized different materials by using some different classes of glass. These materials owned a superconducting transition close to the one of the pure YBa2CU3O{7-δ} material. We made a slurry with the most significant composite materials and binders, and screen-printed them on an alumina substrate preliminary or not coated with a diffusion barrier layer. After firing, we studied the thick films adhesion, the alumina/glass/composite material interfaces, and their superconducting properties. Les nouveaux matériaux supraconducteurs à haute température critique ont potentiellement un rôle important à jouer dans le domaine de l'électronique et de l'électrotechnique. En particulier, le dépôt d'oxydes supraconducteurs sur divers types de substrats est une technologie amenée à se développer. Nous avons donc entrepris une étude dont l'objet est la réalisation de conducteurs sérigraphiés sur alumine et composés essentiellement du matériau YBa2CU3O{7-δ}. Nous avons tout d'abord cherché à réaliser un composite verre/YBa2CU3O{7-δ}, par analogie au principe de réalisation de couches conductrices sérigraphiées, le verre permettant d'obtenir une liaison physico-chimique avec le substrat. Une étude préliminaire a permis de réaliser divers matériaux composites massifs, utilisant différentes familles de verres. Ces matériaux massifs, se présentant sous la forme de barreaux de

  16. Radio-opaque dental compositions

    International Nuclear Information System (INIS)

    Temin, S.C.

    1979-01-01

    Thorium oxide or tantalum oxide, or combinations thereof are used as the x-ray material for radio-opaque filler compositions having particular applicability in dental restorative compositions. The filler compositions contain from about 3% by weight to about 10% by weight, based on the total filler composition, of the x-ray absorbing materials and the remainder being conventional particulate glass or silica, quarts or ceramic filler material. The radio opaque filler compositions are insoluble and non-leachable in alkaline, acidic or neutral aqueous environments, are essentially non-toxic, are either essentially colorless or translucent, and are compatible with acrylic monomers and other polymerizable binder systems

  17. Coating material composition

    International Nuclear Information System (INIS)

    Kimura, Tadashi; Ozeki, Takao; Kobayashi, Juichi; Nakamoto, Hideo; Maeda, Yutaka.

    1969-01-01

    A coating material composition is provided which can easily be cross-linked by irradiation with active energy, particularly electron beams and ultraviolet light, using a mixture of a prepolymer (a) with an addition reaction product (b). Such compositions have coating properties as good as thermosetting acrylic or amino alkyd resins. The prepolymer (a) is produced by primarily reacting at least 0.1 mol of saturated cyclocarboxylic acid anhydrides and/or alpha-, beta-ethylene unsaturated carboxylic acid anhydrides by addition reaction with one mol of hydroxyl radicals of a basic polymer having a molecular weight of 1,000 to 100,000, the basic polymer being obtained from 1%-40% of a hydroxyl radical containing vinyl monomer and at least 30% of (meth)acrylate monomer. One mol of the sum of hydroxyl radicals and carboxyl radicals of the primary reaction product undergoes a secondary addition reaction with at least 0.1 mol of an epoxy radical-containing vinyl monomer to form the prepolymer(a). The addition reaction product(b) is produced by reacting an epoxy radical-containing vinyl monomer with alpha-, beta-ethylene unsaturated carboxylic acids or their anhydrides. The coating material composition contains a majority of a mixture consisting of 10%-90% of (a) and 90%-10% of (b) above by weight. Four examples of the production of basic polymers, seven examples of the production of prepolymers, seven examples of the production of oligomers, and five examples of applications are given. (Iwakiri, K.)

  18. Heterogeneous dissipative composite structures

    Science.gov (United States)

    Ryabov, Victor; Yartsev, Boris; Parshina, Ludmila

    2018-05-01

    The paper suggests mathematical models of decaying vibrations in layered anisotropic plates and orthotropic rods based on Hamilton variation principle, first-order shear deformation laminated plate theory (FSDT), as well as on the viscous-elastic correspondence principle of the linear viscoelasticity theory. In the description of the physical relationships between the materials of the layers forming stiff polymeric composites, the effect of vibration frequency and ambient temperature is assumed as negligible, whereas for the viscous-elastic polymer layer, temperature-frequency relationship of elastic dissipation and stiffness properties is considered by means of the experimentally determined generalized curves. Mitigation of Hamilton functional makes it possible to describe decaying vibration of anisotropic structures by an algebraic problem of complex eigenvalues. The system of algebraic equation is generated through Ritz method using Legendre polynomials as coordinate functions. First, real solutions are found. To find complex natural frequencies of the system, the obtained real natural frequencies are taken as input values, and then, by means of the 3rd order iteration method, complex natural frequencies are calculated. The paper provides convergence estimates for the numerical procedures. Reliability of the obtained results is confirmed by a good correlation between analytical and experimental values of natural frequencies and loss factors in the lower vibration tones for the two series of unsupported orthotropic rods formed by stiff GRP and CRP layers and a viscoelastic polymer layer. Analysis of the numerical test data has shown the dissipation & stiffness properties of heterogeneous composite plates and rods to considerably depend on relative thickness of the viscoelastic polymer layer, orientation of stiff composite layers, vibration frequency and ambient temperature.

  19. Composite materials design and applications

    CERN Document Server

    Gay, Daniel; Tsai, Stephen W

    2002-01-01

    PART ONE. PRINCIPLES OF CONSTRUCTIONCOMPOSITE MATERIALS, INTEREST AND PROPERTIESWhat is Composite Material Fibers and MatrixWhat can be Made Using Composite Materials?Typical Examples of Interest on the Use of Composite MaterialsExamples on Replacing Conventional Solutions with CompositesPrincipal Physical PropertiesFABRICATION PROCESSESMolding ProcessesOther Forming ProcessesPractical Hints in the Manufacturing ProcessesPLY PROPERTIESIsotropy and AnisotropyCharacteristics of the Reinforcement-Matrix MixtureUnidirectional PlyWoven FabricsMats and Reinforced MatricesMultidimensional FabricsMetal Matrix CompositesTestsSANDWICH STRUCTURES:What is a Sandwich Structure?Simplified FlexureA Few Special AspectsFabrication and Design ProblemsNondestructive Quality ControlCONCEPTION AND DESIGNDesign of a Composite PieceThe LaminateFailure of LaminatesSizing of LaminatesJOINING AND ASSEMBLYRiveting and BoltingBondingInsertsCOMPOSITE MATERIALS AND AEROSPACE CONSTRUCTIONAircraftHelicoptersPropeller Blades for AirplanesTur...

  20. A waterproof composition

    Energy Technology Data Exchange (ETDEWEB)

    Uemura, M; Sato, Y

    1983-06-29

    The composition, which is effective for isolating an oozy slurry, water and cement ooze in a well with breaks in a stratum, contains bentonite, a filler (N), for which a fiberous material may be used, a petroleum product (NP), a surfacant (PAV) and a binder (S), hydrogen from shells from Persian wallnuts, feed husks, gilsonite, diatomite, peat coke, ground stone, brick or concrete, glass fragments, rubber cord and so on; a fiberous material (cotton, wood fiber, cellulose mass, fiberglass, leather sections and so on). It also contains petroleum product kerosene, boiler fuel, lubricating oil or petroleum residues, C bitumen, resin, carboxymethylcelulose, polyvinyl sulfide and pitch.

  1. Composite magnetic particles

    International Nuclear Information System (INIS)

    Davies, G.E.; Janata, J.

    1981-01-01

    This patent claim on behalf of I.C.I. Ltd., relates to the preparation and use of composite magnetic particles, comprising a low density core, and having a magnetic coating over at least a proportion of the surface. The density of such particles can be chosen to suit a range of applications, e.g. in affinity chromatography, in radioimmunoassay, in the transport of the associated component, such as a drug or enzyme, to a specific site in a living organism. (U.K.)

  2. Radiation polymerizable compositions

    International Nuclear Information System (INIS)

    Goff, D.L.; Yuan, E.L.; Proskow, S.

    1982-01-01

    A polyamide ester resin containing photopolymerizable groups is made more rapidly photopolymerizable and therefore more suitable for forming relief structures on electrical devices (such as capacitors, integrated circuits and semiconductors) by including therein a solvent, a radiation-sensitive polymerizable polyfunctional acrylate compound and an aromatic biimidazole photopolymerization initiator. On exposure through a pattern of a dried film obtained using a solution of such composition, photopolymerization takes place rapidly and efficiently following which developing can be effected and the photopolymerized material baked to leave a heat-resistant polyimide structure. (author)

  3. Composite hadron models

    International Nuclear Information System (INIS)

    Ogava, S.; Savada, S.; Nakagava, M.

    1983-01-01

    Composite models of hadrons are considered. The main attention is paid to the Sakata, S model. In the framework of the model it is presupposed that proton, neutron and Λ particle are the fundamental particles. Theoretical studies of unknown fundamental constituents of a substance have led to the creation of the quark model. In the framework of the quark model using the theory of SU(6)-symmetry the classification of mesons and baryons is considered. Using the quark model relations between hadron masses, their spins and electromagnetic properties are explained. The problem of three-colour model with many flavours is briefly presented

  4. Toughening of Zirconia composites

    International Nuclear Information System (INIS)

    Burlingame, N.H.

    1980-06-01

    The addition of a ZrO 2 dispersion can significantly enhance the toughness of a ceramic matrix material. The toughness improvement is due to a stress reduction at the tip of a propagating crack which is the result of a preferential martensitic transformation of ZrO 2 particles in the stress field of the crack. From thermodynamic considerations and experimental observations the toughening effect is show to be strongly dependent on the ZrO 2 particle size. The effect of variations in temperature, composition and matrix materials are demonstrated, and analyzed in respect to the resultant deviations in the particle size toughening effect

  5. Compound composite odontoma

    Directory of Open Access Journals (Sweden)

    S Kailasam

    2012-01-01

    Full Text Available Odontomas are the most common type of odontogenic tumors and generally they are asymptomatic. Frequently, it may interfere with the eruption of the teeth. This is a case report of a compound composite odontoma in a 10-year-old girl, which results in failure of eruption of the permanent upper right central incisor while the contralateral tooth had erupted. A calcified mass was seen in the radiograph and was provisionally diagnosed as odontoma following which the odontoma was enucleated. Routine follow-up was done for more than a year and no recurrence was seen. This case report indicates that early diagnosis and management ensures better prognosis.

  6. Parametric compositional data types

    DEFF Research Database (Denmark)

    Bahr, Patrick; Hvitved, Tom

    2012-01-01

    In previous work we have illustrated the benefits that compositional data types (CDTs) offer for implementing languages and in general for dealing with abstract syntax trees (ASTs). Based on Swierstra's data types \\'a la carte, CDTs are implemented as a Haskell library that enables the definition...... of recursive data types and functions on them in a modular and extendable fashion. Although CDTs provide a powerful tool for analysing and manipulating ASTs, they lack a convenient representation of variable binders. In this paper we remedy this deficiency by combining the framework of CDTs with Chlipala...

  7. Composite turbine bucket assembly

    Science.gov (United States)

    Liotta, Gary Charles; Garcia-Crespo, Andres

    2014-05-20

    A composite turbine blade assembly includes a ceramic blade including an airfoil portion, a shank portion and an attachment portion; and a transition assembly adapted to attach the ceramic blade to a turbine disk or rotor, the transition assembly including first and second transition components clamped together, trapping said ceramic airfoil therebetween. Interior surfaces of the first and second transition portions are formed to mate with the shank portion and the attachment portion of the ceramic blade, and exterior surfaces of said first and second transition components are formed to include an attachment feature enabling the transition assembly to be attached to the turbine rotor or disk.

  8. Composition superconductive plumbous coatings

    International Nuclear Information System (INIS)

    Volodin, V.N.; Tuleushev, A.Zh.; Tuleushev, Yu.Zh.; Lisizin, V.N.

    2002-01-01

    Independent dispersion of two or more targets, precipitation of pulverized material on substrate and possibility of composition change in wide range of component concentrations made possible ion-plasma forming of film composition materials from materials with different chemical and physical qualities, particularly in lead-aluminum, lead-beryllium and lead-graphite systems. Named systems are characterized in wide sphere of immiscibility in solid and liquid state and absence of intermediate compounds. It is impossible to receive materials from them in traditional method in conditions of gravitational field. In lead-aluminum system there was received a number of film coatings with aluminum content up to 95 at. % at coating thickness up to 2 μm. Owing to X-ray investigations it is fixed that lead and aluminum have been performed by separate phases. Lead in sprayed layer represents well-crystallized phase with grain size more than 100 nm; texturing is not found. Study of physical qualities has shown that materials with lead base 21.6 at. % Al) have enough high crystalline current in comparison with compact lead, which reaches (2.5-3.0)·10 5 A)·cm 2 , while materials with aluminum base (21.6 at. % Al) loose this effect and critical temperature of transition is reduced from 7.1 to 5.8 K. It was impossible to carry out X-rayed analysis for lead-beryllium film because of weak intensity of beryllium lines against a background of lead owing to a quite large difference of atomic balance. Cryogen tests have shown the increase of critical current strength up to (3.1-3.6)·10 4 A)·cm 2 or composition coating of lead-beryllium (56.99 at. % or 5,45 mas. % Be), at that the critical temperature of transition does not differ from lead temperature. Samples of lead edge of state diagram have been received in the lead-graphite system. X-ray investigation subjected coating contained 6.81 at. % (55.82 mas. %) of lead. Choice of the composition is conditioned on possibilities of

  9. Performance calculations on the ANFO explosive RX-HD

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P.C.; Larson, D.B.; Tarver, C.M.

    1994-12-31

    This report presents the calculation methods utilized in asessing the detonation performance of the ammonium nitrate-fuel oil (ANFO) utilized in the non-proliferation experiment (NPE) underground explosion at te Nevada Test Site. The composition of the ANFO is discussed.

  10. Terahertz composite imaging method

    Institute of Scientific and Technical Information of China (English)

    QIAO Xiaoli; REN Jiaojiao; ZHANG Dandan; CAO Guohua; LI Lijuan; ZHANG Xinming

    2017-01-01

    In order to improve the imaging quality of terahertz(THz) spectroscopy, Terahertz Composite Imaging Method(TCIM) is proposed. The traditional methods of improving THz spectroscopy image quality are mainly from the aspects of de-noising and image enhancement. TCIM breaks through this limitation. A set of images, reconstructed in a single data collection, can be utilized to construct two kinds of composite images. One algorithm, called Function Superposition Imaging Algorithm(FSIA), is to construct a new gray image utilizing multiple gray images through a certain function. The features of the Region Of Interest (ROI) are more obvious after operating, and it has capability of merging ROIs in multiple images. The other, called Multi-characteristics Pseudo-color Imaging Algorithm(McPcIA), is to construct a pseudo-color image by combining multiple reconstructed gray images in a single data collection. The features of ROI are enhanced by color differences. Two algorithms can not only improve the contrast of ROIs, but also increase the amount of information resulting in analysis convenience. The experimental results show that TCIM is a simple and effective tool for THz spectroscopy image analysis.

  11. AP English language & composition

    CERN Document Server

    Bureau, Susan; Allen, John; Nesselrode, Katherine A; McGauley, Kristi R; Nesselrode, Katherine A; McGauley, Kristi R

    2013-01-01

    All Access for the AP® English Language and Composition Exam Book + Web + Mobile Everything you need to prepare for the Advanced Placement® exam, in a study system built around you! There are many different ways to prepare for an Advanced Placement® exam. What's best for you depends on how much time you have to study and how comfortable you are with the subject matter. To score your highest, you need a system that can be customized to fit you: your schedule, your learning style, and your current level of knowledge. This book, and the online tools that come with it, will help you personalize your AP® English Language and Composition prep by testing your understanding, pinpointing your weaknesses, and delivering flashcard study materials unique to you. The REA AP® All Access system allows you to create a personalized study plan through three simple steps: targeted review of exam content, assessment of your knowledge, and focused study in the topics where you need the most help. Here's how it works: Review ...

  12. Interacting composite fermions

    DEFF Research Database (Denmark)

    nrc762, nrc762

    2016-01-01

    Numerical studies by Wójs, Yi, and Quinn have suggested that an unconventional fractional quantum Hall effect is plausible at filling factors ν=1/3 and 1/5, provided the interparticle interaction has an unusual form for which the energy of two fermions in the relative angular momentum three channel...... as fractional quantum Hall effect of electrons at ν=4/11, 4/13, 5/13, and 5/17. I investigate in this article the nature of the fractional quantum Hall states at ν=4/5, 5/7, 6/17, and 6/7, which correspond to composite fermions at ν∗=4/3, 5/3, and 6/5, and find that all these fractional quantum Hall states...... are conventional. The underlying reason is that the interaction between composite fermions depends substantially on both the number and the direction of the vortices attached to the electrons. I also study in detail the states with different spin polarizations at 6/17 and 6/7 and predict the critical Zeeman...

  13. Microsurgical Composite Tissue Transplantation

    Science.gov (United States)

    Serafin, Donald; Georgiade, Nicholas G.

    1978-01-01

    Since 1974, 69 patients with extensive defects have undergone reconstruction by microsurgical composite tissue transplantation. Using this method, donor composite tissue is isolated on its blood supply, removed to a distant recipient site, and the continuity of blood flow re-established by microvascular anastomoses. In this series, 56 patients (81%) were completely successful. There have been eight (12%) failures, primarily in the extremities. There have been five (7%) partial successes, (i.e., a microvascular flap in which a portion was lost requiring a secondary procedure such as a split thickness graft). In those patients with a severely injured lower extremity, the failure rate was the greatest. Most of these were arterial (six of seven). These failures occurred early in the series and were thought to be related to a severely damaged recipient vasculature. This problem has been circumvented by an autogenous interpositional vein graft, permitting more mobility of flap placement. In the upper extremity, all but one case were successful. Early motion was permitted, preventing joint capsular contractures and loss of function. Twenty-three cases in the head and neck region were successful (one partial success). This included two composite rib grafts to the mandible. Prolonged delays in reconstruction following extirpation of a malignancy were avoided. A rapid return to society following complete reconstruction was ensured. Nine patients presented for reconstruction of the breast and thorax following radical mastectomy. All were successfully reconstructed with this new technique except one patient. Its many advantages include immediate reconstruction without delayed procedures and no secondary deformity of the donor site. Healthy, well vascularized tissue can now be transferred to a previously irradiated area with no tissue loss. This new method offers many advantages to older methods of reconstruction. Length of hospital stay and immobilization are reduced. The

  14. Mechanics in Composite Materials and Process

    International Nuclear Information System (INIS)

    Lee, Dae Gil

    1993-03-01

    This book includes introduction of composite materials, stress, in-plane stiffness of laminates strain rate, ply stress, failure criterion and bending, composite materials micromechanics, composite plates and micromechanics of composite materials. It also deals with process of composite materials such as autoclave vacuum bag degassing process, connection of composite materials, filament winding process, resin transfer molding, sheet molding compound and compression molding.

  15. Composite Materials in Overhead Lines

    DEFF Research Database (Denmark)

    Sørensen, Thomas Kjærsgaard; Holbøll, Joachim

    2009-01-01

    towers and recently conductors based on composite materials are available at transmission levels. In this paper it is investigated which composite based solutions are available in connection with complete overhead line systems including insulators, towers and conductors. The components are reviewed......The use of composite materials, e.g. fibreglass materials, in overhead transmission line systems is nothing new. Composite based insulators have been applied to transmission lines for over 30 years, mainly as suspension and post insulators and often as an option for special applications. Also...... with respect to solved and persisting known failures/problems of both mechanical and electrical nature. Major challenges related to extensive use of composite materials in an overhead line system are identified, as are possible benefits - both when using standard as well as customised composite components, e...

  16. Damage growth in aerospace composites

    CERN Document Server

    2015-01-01

    This book presents novel methods for the simulation of damage evolution in aerospace composites that will assist in predicting damage onset and growth and thus foster less conservative designs which realize the promised economic benefits of composite materials. The presented integrated numerical/experimental methodologies are capable of taking into account the presence of damage and its evolution in composite structures from the early phases of the design (conceptual design) through to the detailed finite element method analysis and verification phase. The book is based on the GARTEUR Research Project AG-32, which ran from 2007 to 2012, and documents the main results of that project. In addition, the state of the art in European projects on damage evolution in composites is reviewed. While the high specific strength and stiffness of composite materials make them suitable for aerospace structures, their sensitivity to damage means that designing with composites is a challenging task. The new approaches describ...

  17. Magnetic losses in composite materials

    International Nuclear Information System (INIS)

    Ramprecht, J; Sjoeberg, D

    2008-01-01

    We discuss some of the problems involved in homogenization of a composite material built from ferromagnetic inclusions in a nonmagnetic background material. The small signal permeability for a ferromagnetic spherical particle is combined with a homogenization formula to give an effective permeability for the composite material. The composite material inherits the gyrotropic structure and resonant behaviour of the single particle. The resonance frequency of the composite material is found to be independent of the volume fraction, unlike dielectric composite materials. The magnetic losses are described by a magnetic conductivity which can be made independent of frequency and proportional to the volume fraction by choosing a certain bias. Finally, some concerns regarding particles of small size, i.e. nanoparticles, are treated and the possibility of exciting exchange modes are discussed. These exchange modes may be an interesting way to increase losses in composite materials

  18. Precursor polymer compositions comprising polybenzimidazole

    Science.gov (United States)

    Klaehn, John R.; Peterson, Eric S.; Orme, Christopher J.

    2015-07-14

    Stable, high performance polymer compositions including polybenzimidazole (PBI) and a melamine-formaldehyde polymer, such as methylated, poly(melamine-co-formaldehyde), for forming structures such as films, fibers and bulky structures. The polymer compositions may be formed by combining polybenzimidazole with the melamine-formaldehyde polymer to form a precursor. The polybenzimidazole may be reacted and/or intertwined with the melamine-formaldehyde polymer to form the polymer composition. For example, a stable, free-standing film having a thickness of, for example, between about 5 .mu.m and about 30 .mu.m may be formed from the polymer composition. Such films may be used as gas separation membranes and may be submerged into water for extended periods without crazing and cracking. The polymer composition may also be used as a coating on substrates, such as metal and ceramics, or may be used for spinning fibers. Precursors for forming such polymer compositions are also disclosed.

  19. Composite Dos Attack Model

    Directory of Open Access Journals (Sweden)

    Simona Ramanauskaitė

    2012-04-01

    Full Text Available Preparation for potential threats is one of the most important phases ensuring system security. It allows evaluating possible losses, changes in the attack process, the effectiveness of used countermeasures, optimal system settings, etc. In cyber-attack cases, executing real experiments can be difficult for many reasons. However, mathematical or programming models can be used instead of conducting experiments in a real environment. This work proposes a composite denial of service attack model that combines bandwidth exhaustion, filtering and memory depletion models for a more real representation of similar cyber-attacks. On the basis of the introduced model, different experiments were done. They showed the main dependencies of the influence of attacker and victim’s properties on the success probability of denial of service attack. In the future, this model can be used for the denial of service attack or countermeasure optimization.

  20. Novel nanohybrid MTA compositions

    DEFF Research Database (Denmark)

    Lovschall, Henrik; Ranjkesh, Bahram

    Original Mineral Trioxide Aggregate (MTA) has been recommended for various uses in endodontics. MTA is a calcia, silica, alumina containing hydraulic cement with long setting time, calcium hydroxide release, and high pH. It possesses antibacterial and sealing properties. Interestingly, recent...... studies describe hydroxyapatite crystals form over MTA when it comes in contact with simulated physiological tissue fluid. On the basis of available evidence it appears that MTA efficiently develop superior marginal adaptation in humid environments. Observations suggest MTA is suitable material for pulp...... modified calcia-silica-alumina-sulphate composition with soluble fluorides, radiocontrast material, and nanosilicate. iMTA thereby demonstrate a remarkably high compressive strength in comparison to several commonly used dental cements. Reduction of iMTA setting time to 2-10 min with either flowable...

  1. Chemical composition of patikaraparpam.

    Science.gov (United States)

    Saraswathy, A; Rani, M G; Susan, T; Purushothaman, K K

    1997-04-01

    Patikaraparpam, a Siddha formulation in prepared by trituration of potash alum with egg albumin followed by calcinatin. The three authentic laboratories made parpams as well as six commercial samples have been examined for their chemical composition. The analytical data that emerged from the analysis of the above samples showed that seven parpams contained only aluminium sulphate and they did respond to tests for potassium. An inspection of the crude drugs patikaram' available in the market established that potash alum and ammonia alum are indiscriminateldy taken for use, according to literature, only potash alum should be used in Indian system of medicine. Patikarapparapam is indicated in urinary inflammations and obstructions and is a reputed diuretic. Potassium salts are established diuretic. These studies show that the raw drugs sellers, the pharamaceutists or manufacturers of medicine and the physician as well should make sure that only potash alum is used in Indian medicine.

  2. Nanostructured composite reinforced material

    Science.gov (United States)

    Seals, Roland D [Oak Ridge, TN; Ripley, Edward B [Knoxville, TN; Ludtka, Gerard M [Oak Ridge, TN

    2012-07-31

    A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

  3. Comets and their composition

    International Nuclear Information System (INIS)

    Spinrad, H.

    1987-01-01

    Recent theoretical and observational studies of comets are reviewed, with an emphasis on in situ data from spacecraft encounters with P/Giacobini-Zinner (September 1985) and P/Halley (March 1986). Topics addressed include clues on the origin and permanence of the Oort cometary cloud, observations of cometary nuclei far from the sun, the Halley nucleus, compositional and physical data from comae studies, and the parent molecules in comet ices. Also discussed are quantitative analyses of coma production; special features in the tail of P/Giacobini-Zinner; and proposals for (1) observations to detect distant giant comets, (2) high-resolution spectroscopic studies of comae, and (3) additional spacecraft missions such as the NASA Comet Rendezvous and Asteroid Flyby. 121 references

  4. Novel high explosive compositions

    Science.gov (United States)

    Perry, D.D.; Fein, M.M.; Schoenfelder, C.W.

    1968-04-16

    This is a technique of preparing explosive compositions by the in-situ reaction of polynitroaliphatic compounds with one or more carboranes or carborane derivatives. One or more polynitroaliphatic reactants are combined with one or more carborane reactants in a suitable container and mixed to a homogeneous reaction mixture using a stream of inert gas or conventional mixing means. Ordinarily the container is a fissure, crack, or crevice in which the explosive is to be implanted. The ratio of reactants will determine not only the stoichiometry of the system, but will effect the quality and quantity of combustion products, the explosive force obtained as well as the impact sensitivity. The test values can shift with even relatively slight changes or modifications in the reaction conditions. Eighteen illustrative examples accompany the disclosure. (46 claims)

  5. Composition of Estonian atmosphere

    International Nuclear Information System (INIS)

    Punning, J. M.; Karindi, A.

    1996-01-01

    Atmospheric study, particularly that of its chemical composition, has a long tradition in Estonia. Since middle of this century, in addition to meteorological observations, some chemical compounds in precipitations have been regularly measured in many meteorological stations. The main aim was to acquire information about the state and dynamics of the atmosphere. Therefore, main attention was paid to monitoring chemical compounds which have a direct impact on the human environment. As energy production developed intensively and SO 2 and NO x increased drastically in the atmosphere in acidic rock areas, like Scandinavia, the problem of acid rain became the most important environmental problem in Europe and North-America. As a consequence, monitoring the compounds of sulphur in precipitation was organized in Estonia. In the 1970 s, as related to large operating oil shale-based power plants, Estonia became a country , where emissions of sulphur compounds per capita were extremely high. In 1979, Estonia became a participant in the European Monitoring and Evaluation Programme - the network created to study transboundary air pollution. The aims of the precipitation chemistry study and the related problems of the formation and transformation of the atmospheric composition have varied over the years. But monitoring of pollutant (in particular, sulphur compound) loads has been a central issue. Over recent years, an attempt was made to estimate the spatial regularities of atmospheric impurities and their impact on the pH of mean monthly precipitations. Furthermore, calculations were provided to find out the origin of atmospheric impurities washed out in Estonia. Until the 1990 s, CO 2 , and some other greenhouse gas (GHG) emissions were not studied in Estonia. The first inventory of GHG for Estonia was provided in 1995 using the Intergovernmental Panel on Climate Change (IPCC) methodology

  6. Graphene-ionic liquid composites

    Energy Technology Data Exchange (ETDEWEB)

    Aksay, Ilhan A.; Korkut, Sibel; Pope, Michael; Punckt, Christian

    2016-11-01

    Method of making a graphene-ionic liquid composite. The composite can be used to make elec-trodes for energy storage devices, such as batteries and supercapacitors. Dis-closed and claimed herein is method of making a graphene-ionic liquid com-posite, comprising combining a graphene source with at least one ionic liquid and heating the combination at a temperature of at least about 130 .degree. C.

  7. Nano-composite stainless steel

    Science.gov (United States)

    Dehoff, Ryan R.; Blue, Craig A.; Peter, William H.; Chen, Wei; Aprigliano, Louis F.

    2015-07-14

    A composite stainless steel composition is composed essentially of, in terms of wt. % ranges: 25 to 28 Cr; 11 to 13 Ni; 7 to 8 W; 3.5 to 4 Mo; 3 to 3.5 B; 2 to 2.5 Mn; 1 to 1.5 Si; 0.3 to 1.7 C; up to 2 O; balance Fe. The composition has an austenitic matrix phase and a particulate, crystalline dispersed phase.

  8. Superconducting composite for magnetic bearings

    International Nuclear Information System (INIS)

    Rigney, T.K. II.

    1995-01-01

    A composite includes granules of Type II superconducting material and granules of rare-earth permanent magnets that are distributed in a binder. The composite is a two-phase structure that combines the properties of the superconductor and magnets with the flexibility and toughness of a polymeric material. A bearing made from this composite has the load capacity and stiffness of a permanent magnet bearing with added stability from a Type II superconducting material. 7 figs

  9. A Generator for Composition Interpreters

    DEFF Research Database (Denmark)

    Steensgaard-Madsen, Jørgen

    1997-01-01

    programming language design, specification and implementation then apply. A component can be considered as defining objects or commands according to convenience. A description language including type information provides sufficient means to describe component interaction according to the underlying abstract......Composition of program components must be expressed in some language, and late composition can be achieved by an interpreter for the composition language. A suitable notion of component is obtained by identifying it with the semantics of a generalised structured command. Experiences from...

  10. Electrospun Fibers for Composites Applications

    Science.gov (United States)

    2014-02-01

    in traditional woven mat composites. Nanofibrous interlayers were used to increase the impact and shear performance of a prepregged carbon fiber...Nylon 66 Nanofibrilmat Interleaved Carbon/Epoxy Laminates . Polymer Composites 2011, 32, 1781–1789. 21 13. Chen, Q.; Zhang, L.; Rahman, A.; Zhou...Resistance in Laminated Composites With Electrospun Nano-Interlayers. Comp. Sci. Tech. 2008, 68, 673– 683. 15. Zhang, J.; Lin, T.; Wang, X. Electrospun

  11. Cast dielectric composite linear accelerator

    Science.gov (United States)

    Sanders, David M [Livermore, CA; Sampayan, Stephen [Manteca, CA; Slenes, Kirk [Albuquerque, NM; Stoller, H M [Albuquerque, NM

    2009-11-10

    A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.

  12. Research progress of composite fillers

    Directory of Open Access Journals (Sweden)

    Yixuan ZHAO

    2015-08-01

    Full Text Available Using composite filler is a very potential way to braze dissimilar material, especially braze metals with ceramics. The composite filler which is added varieties of high temperature alloy, carbon fiber and ceramic particles has a suitable coefficient of thermal expansion. The application of composite filler can release the residual stress caused by mismatch of thermal expansion coefficient in the brazing joints and improve the overall performance significantly. According to the traditional classification method of composite materials, the composite filler is divided into micron-reinforced composite filler and nano-reinforced composite filler, of which the feature and research status are discussed in this text. According to the influence of different size reinforced phases on microstructure and mechanical property of the brazing joints, nano-reinforced composite filler has more uniform and better structure compared with micron-reinforced composite filler, and higher joint strengh can be obtained by using it. However, the reinforced mechanism is still an open question, and will become the key area of the future research work.

  13. Multifunctional Composite Materials, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Polymeric composite materials that are currently utilized in aircraft structures are susceptible to significant damage from lightning strikes. Enhanced electrical...

  14. Deformation Characteristics of Composite Structures

    Directory of Open Access Journals (Sweden)

    Theddeus T. AKANO

    2016-08-01

    Full Text Available The composites provide design flexibility because many of them can be moulded into complex shapes. The carbon fibre-reinforced epoxy composites exhibit excellent fatigue tolerance and high specific strength and stiffness which have led to numerous advanced applications ranging from the military and civil aircraft structures to the consumer products. However, the modelling of the beams undergoing the arbitrarily large displacements and rotations, but small strains, is a common problem in the application of these engineering composite systems. This paper presents a nonlinear finite element model which is able to estimate the deformations of the fibre-reinforced epoxy composite beams. The governing equations are based on the Euler-Bernoulli beam theory (EBBT with a von Kármán type of kinematic nonlinearity. The anisotropic elasticity is employed for the material model of the composite material. Moreover, the characterization of the mechanical properties of the composite material is achieved through a tensile test, while a simple laboratory experiment is used to validate the model. The results reveal that the composite fibre orientation, the type of applied load and boundary condition, affect the deformation characteristics of the composite structures. The nonlinearity is an important factor that should be taken into consideration in the analysis of the fibre-reinforced epoxy composites.

  15. Application of Composite Polymer Electrolytes

    National Research Council Canada - National Science Library

    Scrosati, Bruno

    2001-01-01

    ...)PEO-based composite polymer electrolytes, by a series of specifically addressed electrochemical tests which included the determination of the conductivity and of the lithium transference number...

  16. Composite membrane with integral rim

    Science.gov (United States)

    Routkevitch, Dmitri; Polyakov, Oleg G

    2015-01-27

    Composite membranes that are adapted for separation, purification, filtration, analysis, reaction and sensing. The composite membranes can include a porous support structure having elongate pore channels extending through the support structure. The composite membrane also includes an active layer comprising an active layer material, where the active layer material is completely disposed within the pore channels between the surfaces of the support structure. The active layer is intimately integrated within the support structure, thus enabling great robustness, reliability, resistance to mechanical stress and thermal cycling, and high selectivity. Methods for the fabrication of composite membranes are also provided.

  17. Multilayer Electroactive Polymer Composite Material

    Science.gov (United States)

    Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Park, Cheol (Inventor); Draughon, Gregory K. (Inventor); Ounaies, Zoubeida (Inventor)

    2011-01-01

    An electroactive material comprises multiple layers of electroactive composite with each layer having unique dielectric, electrical and mechanical properties that define an electromechanical operation thereof when affected by an external stimulus. For example, each layer can be (i) a 2-phase composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation, or (ii) a 3-phase composite having the elements of the 2-phase composite and further including a third component of micro-sized to nano-sized particles of an electroactive ceramic incorporated in the polymer matrix.

  18. Chemical composition and strength of dolomite geopolymer composites

    Science.gov (United States)

    Aizat, E. A.; Al Bakri, A. M. M.; Liew, Y. M.; Heah, C. Y.

    2017-09-01

    The chemical composition of dolomite and the compressive strength of dolomite geopolymer composites were studied. The both composites prepared with mechanical mixer manufactured by with rotor speed of 350 rpm and curing in the oven for 24 hours at 80˚C. XRF analysis showThe dolomite raw materials contain fewer amounts of Si and Al but high Ca in its composition. Dolomite geopolymer composites with 20M of NaOH shows greater and optimum compressive strength compared to dolomite geopolymer with other NaOH molarity. This indicated better interaction of dolomite raw material and alkaline activator need high molarity of NaOH in order to increase the reactivity of dolomite.

  19. Sorption of radiocesium by composites of variable composition

    International Nuclear Information System (INIS)

    Someda, H.H.; El-zahhar, A.A.; Shehata, M.K.K.; El-Naggar, H.A.

    2000-01-01

    Cellulose and different natural materials - supported hexacyanoferrate composites were prepared and characterized by IR and x-ray diffraction studies. The stability of the prepared composites towards concentrated mineral acids was studied. The capacity of such prepared composites towards the uptake of cesium was calculated and found to be 1.5-1.7 meq/g. The capacity of the natural materials - supported composites was found to be slightly higher than that of the cellulose supported one. Different parameters affecting the sorption process of the radioelement such as acid concentration, Ph variation, competing ions and carrier concentration were studied. The release of the cesium traces from the composite materials was studied under different HCl concentrations and it was found that there is no release of the absorbed cesium up to 2.5 M even for long contact time up to two weeks. The work is under developing and extension

  20. Assessment of first-year post-graduate residents: Usefulness of multiple tools

    Directory of Open Access Journals (Sweden)

    Ying-Ying Yang

    2011-12-01

    Conclusion: The strong correlations between 360-degree evaluation and small-scale OSCE+DOPS+IM-ITE®-composited scores suggested that both methods were measuring the same quality. Our results showed that the small-scale OSCE, when associated with both the DOPS and IM-ITE®, could be an important assessment method for PGY1 residents.

  1. Rigidified pneumatic composites

    Science.gov (United States)

    van Dessel, Steven

    2000-10-01

    The overall objective of the research presented in this dissertation was to address global issues of adequate housing for all and the need for more sustainable human settlement. In order to address these, the emerging technology of rigidified pneumatic composites was investigated. Rigidified pneumatic composites (RPC) are defined as thin flexible membrane structures that are pneumatically deployed. After deployment, these structures harden due to chemical or physical change of the membrane. Because of this change, these structures do no longer require pneumatic pressure to maintain their shape. For the first time, a systematic listing of the various means available to develop polymeric materials useful in RPC technology is presented. With the aim to reduce the cost of RPC structures, a new material was proposed, developed, and evaluated. This material involved the formation of a semi-interpenetrating polymer network based on poly vinyl chloride and an acrylate based reactive plasticizer. The economical and environmental performances of RPC structures using this new material were assessed by means of a case study. In this study, the performance of RPC technology was compared with that of a typical wood light frame structure in the application of a small single-family house. The study indicated that the cost of ownership in present day value for the RPC structure was approximately 33% less than the cost of a comparable wood light frame structure. The study also indicated that significant environmental benefits exist with the use of RPC structures. It was found that the RPC structure used significantly less resources compared to the wood light frame structure. About 3.5 times less materials coming from non-renewable fossil resources, about 2.5 times less materials coming from trees, and about 19 times less materials coming from inorganic resources was used in the RPC structure relative to the wood light frame structure. The study concluded with pointing out various

  2. Nanocellulose reinforcement of Transparent Composites

    Science.gov (United States)

    Joshua Steele; Hong Dong; James F. Snyder; Josh A. Orlicki; Richard S. Reiner; Alan W. Rudie

    2012-01-01

    In this work, we evaluate the impact of nanocellulose reinforcement on transparent composite properties. Due to the small diameter, high modulus, and high strength of cellulose nanocrystals, transparent composites that utilize these materials should show improvement in bulk mechanical performances without a corresponding reduction in optical properties. In this study...

  3. Composites from wood and plastics

    Science.gov (United States)

    Craig Clemons

    2010-01-01

    Composites made from thermoplastics and fillers or reinforcements derived from wood or other natural fibers are a dynamic research area encompassing a wide variety of composite materials. For example, as the use of biopolymers grows, wood and other natural fiber sources are being investigated as renewable sources of fillers and reinforcements to modify performance....

  4. Wood and concrete polymer composites

    International Nuclear Information System (INIS)

    Singer, K.

    1974-01-01

    There are several ways to prepare and use wood and concrete polymer composites. The most important improvements in the case of concrete polymer composites are obtained for compressive and tensile strengths. The progress in this field in United States and other countries is discussed in this rview. (M.S.)

  5. Composite materials processing, applications, characterizations

    CERN Document Server

    2017-01-01

    Composite materials are used as substitutions of metals/traditional materials in aerospace, automotive, civil, mechanical and other industries. The present book collects the current knowledge and recent developments in the characterization and application of composite materials. To this purpose the volume describes the outstanding properties of this class of advanced material which recommend it for various industrial applications.

  6. Stress analysis in FRP composites

    Directory of Open Access Journals (Sweden)

    Nitin Jauhari

    2016-09-01

    Full Text Available A composite material, in mechanics sense, is a structure with the ingredients as element transferring forces to adjacent members. The issue of defects and their effect on the mechanical properties of composites is of great concern among high end users. Experimental investigation of failure modes of composite materials requires correlating the fundamentals of composite materials, their mechanical properties as well as their failure characteristics in the presence of defects. In this paper, three formats of defects of hole (single, double and quadruple as a discontinuity were incorporated along with tensile testing. Unique failure modes of these specimens provided overview regarding mechanical behaviour of composite materials containing defects. Certain correlations were observed between defects and resulting properties. Results are in agreement with general behaviour of FRP composite laminates and it can be concluded that for low deformation in composite laminates, number of layers must be increased, which at the same time results in increase of von-Mises stress. Fibres are the main constituents which are responsible for strength of a composite laminate and they along with fibre orientation, play an important role on its load bearing capacity. It can be inferred based on the analysis that cross-ply configuration [0°/90°] has good load bearing capacity as well as least deflection emphasizing more strength.

  7. Electroless alloy/composite coatings

    Indian Academy of Sciences (India)

    The market for these coatings is expanding fast as the potential applications are on the rise. In the present article, an attempt has been made to review different electroless alloy/composite coatings with respect to bath types and their composition, properties and applications. Different characterisation studies have been ...

  8. Amorphous metal matrix composite ribbons

    International Nuclear Information System (INIS)

    Barczy, P.; Szigeti, F.

    1998-01-01

    Composite ribbons with amorphous matrix and ceramic (SiC, WC, MoB) particles were produced by modified planar melt flow casting methods. Weldability, abrasive wear and wood sanding examinations were carried out in order to find optimal material and technology for elevated wear resistance and sanding durability. The correlation between structure and composite properties is discussed. (author)

  9. Chirality, nongauge couplings and compositeness

    International Nuclear Information System (INIS)

    Suzuki, Mahiko

    1985-01-01

    We study from a phenomenological viewpoint what constraints exist on a possible scale of compositeness for W, Z, leptons, and quarks. A few critical arguments are presented about excited fermions and spinless partners of W and Z. It is argued that irrespective of a compositeness scale, the coupling of an excited fermion to a ground state light fermion is likely to be maximally parity violating. Besides chirality breaking interactions of light fermions, gauge noninvariant, dimensionless, unrenormalizable couplings are specially interesting in many classes of composite theories. The deviation of the W magnetic moment from the standard theory (g = 2) is such an example. We relate the ''g-2'' of W to a compositeness scale through an unitarity argument and make a guess on its effect on the muon g-2 for a given compositeness scale. The present experimental data on the W-Z mass ratio is already accurate enough to indicate that if a compositeness scale is larger than 0(1 TeV), gauge noninvariant couplings of W and Z should be negligibly small and a composite theory is hardly distinguishable from an elementary particle theory at the electroweak energy scale (≅ 250 GeV). However, a compositeness scale close to the electroweak scale can not be ruled out for W and Z at present. (author)

  10. Compositionally Graded Multilayer Ceramic Capacitors.

    Science.gov (United States)

    Song, Hyun-Cheol; Zhou, Jie E; Maurya, Deepam; Yan, Yongke; Wang, Yu U; Priya, Shashank

    2017-09-27

    Multilayer ceramic capacitors (MLCC) are widely used in consumer electronics. Here, we provide a transformative method for achieving high dielectric response and tunability over a wide temperature range through design of compositionally graded multilayer (CGML) architecture. Compositionally graded MLCCs were found to exhibit enhanced dielectric tunability (70%) along with small dielectric losses (filters and power converters.

  11. Ultrasonic Characterization of Aerospace Composites

    Science.gov (United States)

    Leckey, Cara; Johnston, Patrick; Haldren, Harold; Perey, Daniel

    2015-01-01

    Composite materials have seen an increased use in aerospace in recent years and it is expected that this trend will continue due to the benefits of reduced weight, increased strength, and other factors. Ongoing work at NASA involves the investigation of the large-scale use of composites for spacecraft structures (SLS components, Orion Composite Crew Module, etc). NASA is also involved in work to enable the use of composites in advanced aircraft structures through the Advanced Composites Project (ACP). In both areas (space and aeronautics) there is a need for new nondestructive evaluation and materials characterization techniques that are appropriate for characterizing composite materials. This paper will present an overview of NASA's needs for characterizing aerospace composites, including a description of planned and ongoing work under ACP for the detection of composite defects such as fiber waviness, reduced bond strength, delamination damage, and microcracking. The research approaches include investigation of angle array, guided wave, and phase sensitive ultrasonic methods. The use of ultrasonic simulation tools for optimizing and developing methods will also be discussed.

  12. Compositional Synthesis of Safety Controllers

    NARCIS (Netherlands)

    Kuijper, W.

    2012-01-01

    In my thesis I investigate compositional techniques for synthesis of safety controllers. A safety controller, in this context, is a state machine that gives the set of safe control outputs for every possible sequence of observations from the plant under control. Compositionality, in this context,

  13. Radiation-stable polyolefin compositions

    International Nuclear Information System (INIS)

    Rekers, J.W.

    1986-01-01

    This invention relates to compositions of olefinic polymers suitable for high energy radiation treatment. In particular, the invention relates to olefinic polymer compositions that are stable to sterilizing dosages of high energy radiation such as a gamma radiation. Stabilizers are described that include benzhydrol and benzhydrol derivatives; these stabilizers may be used alone or in combination with secondary antioxidants or synergists

  14. Improved di-electric composition

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R C

    1915-03-29

    An improved di-electric composition is disclosed composed of pitch or bitumen which is melted, and to which is added, while molten, a quantity of finely ground or pulverized spent shale, the whole being mixed or stirred to make a homogeneous composition, substantially as described.

  15. Rewetting of composite slab

    International Nuclear Information System (INIS)

    Satapathy, A.K.; Singh, K.C.

    1996-01-01

    The process of re-establishment of wetting of hot surface is of practical importance in chemical, metallurgical and nuclear industries. Rewetting is considered in emergency core cooling in nuclear reactors in the event of postulated loss of coolant accident (LOCA). This paper deals with numerical solution of the two-dimensional quasi-static conduction controlled rewetting of an infinite parallel sided composite slab assuming perfect contact is maintained at the interface. On the wetted side upstream of the quench front, a constant heat transfer coefficient is assumed. The downstream of quench front and unwetted side of slab are supposed to be adiabatic. The solution gives the quench front temperature as a function of various model parameters such as Peclet number, wet side Blot number, dimensionless thickness of slab and cladding to fuel ratio of thermal conductivities. The results show that for large values of rewetting velocities, the dimensionless rewetting temperature is unaffected by fuel properties for all values of Blot numbers. (author). 7 refs., 2 tabs., 1 fig

  16. Composite waste analysis system

    International Nuclear Information System (INIS)

    Wachter, J.R.; Hagan, R.C.; Bonner, C.A.; Malcom, J.E.; Camp, K.L.

    1993-01-01

    Nondestructive analysis (NDA) of radioactive waste forms an integral component of nuclear materials accountability programs and waste characterization acceptance criterion. However, waste measurements are often complicated by unknown isotopic compositions and the potential for concealment of special nuclear materials in a manner that is transparent to gamma-ray measurement instruments. To overcome these complications, a new NDA measurement system has been developed to assay special nuclear material in both transuranic and low level waste from the same measurement platform. The system incorporates a NaI detector and customized commercial software routines to measure small quantities of radioactive material in low level waste. Transuranic waste analysis is performed with a coaxial HPGE detector and uses upgraded PC-based segmented gamma scanner software to assay containers up to 55 gal. in volume. Gamma-Ray isotopics analysis of both waste forms is also performed with this detector. Finally, a small neutron counter using specialized software is attached to the measurement platform to satisfy safeguards concerns related to nuclear materials that are not sensed by the gamma-ray instruments. This report describes important features and capabilities of the system and presents a series of test measurements that are to be performed to define system parameters

  17. Composite Differential Search Algorithm

    Directory of Open Access Journals (Sweden)

    Bo Liu

    2014-01-01

    Full Text Available Differential search algorithm (DS is a relatively new evolutionary algorithm inspired by the Brownian-like random-walk movement which is used by an organism to migrate. It has been verified to be more effective than ABC, JDE, JADE, SADE, EPSDE, GSA, PSO2011, and CMA-ES. In this paper, we propose four improved solution search algorithms, namely “DS/rand/1,” “DS/rand/2,” “DS/current to rand/1,” and “DS/current to rand/2” to search the new space and enhance the convergence rate for the global optimization problem. In order to verify the performance of different solution search methods, 23 benchmark functions are employed. Experimental results indicate that the proposed algorithm performs better than, or at least comparable to, the original algorithm when considering the quality of the solution obtained. However, these schemes cannot still achieve the best solution for all functions. In order to further enhance the convergence rate and the diversity of the algorithm, a composite differential search algorithm (CDS is proposed in this paper. This new algorithm combines three new proposed search schemes including “DS/rand/1,” “DS/rand/2,” and “DS/current to rand/1” with three control parameters using a random method to generate the offspring. Experiment results show that CDS has a faster convergence rate and better search ability based on the 23 benchmark functions.

  18. The advanced composition explorer

    International Nuclear Information System (INIS)

    Stone, E.C.; Burlaga, L.F.; Cummings, A.C.; Feldman, W.C.; Frain, W.E.; Geiss, J.; Gloeckler, G.; Gold, R.E.; Hovestadt, D.; Krimigis, S.M.; Mason, G.M.; McComas, D.; Mewaldt, R.A.; Simpson, J.A.; von Rosenvinge, T.T.; Wiedenbeck, M.E.

    1990-01-01

    The Advanced Composition Explorer (ACE) was recently selected as one of two new Explorer-class missions to be developed for launch during the mid-1990's ACE will observe particles of solar, interplanetary, interstellar, and galactic origins, spanning the energy range from that of the solar wind (∼1 keV/nucleon) to galactic cosmic ray energies (several hundred MeV/nucleon). Definitive studies will be made of the abundance of nearly all isotopes from H to Zn (1≤Z≤30), with exploratory isotope studies extending to Zr(Z=40). To accomplish this, the ACE payload includes six high-resolution spectrometers, each designed to provide the optimum charge, mass, or charge-state resolution in its particular energy range, and each having a geometry factor optimized for the expected flux levels, so as to provide a collecting power a factor of 10 to 1000 times greater than previous or planned experiments. The payload also includes several instruments of standard design that will monitor solar wind and magnetic field conditions and energetic H, He, and electron fluxes. We summarize here the scientific objectives, instrumentation, spacecraft, and mission approach that were defined for ACE during the Phase-A study period

  19. Delamination of Composite Cylinders

    Science.gov (United States)

    Davies, Peter; Carlsson, Leif A.

    The delamination resistance of filament wound glass/epoxy cylinders has been characterized for a range of winding angles and fracture mode ratios using beam fracture specimens. The results reveal that the delamination fracture resistance increases with increasing winding angle and mode II (shear) fraction (GΠ/G). It was also found that interlaced fiber bundles in the filament wound cylinder wall acted as effective crack arresters in mode I loading. To examine the sensitivity of delamina-tion damage on the strength of the cylinders, external pressure tests were performed on filament-wound glass/epoxy composite cylinders with artificial defects and impact damage. The results revealed that the cylinder strength was insensitive to the presence of single delaminations but impact damage caused reductions in failure pressure. The insensitivity of the failure pressure to a single delamination is attributed to the absence of buckling of the delaminated sublaminates before the cylinder wall collapsed. The impacted cylinders contained multiple delaminations, which caused local reduction in the compressive load capability and reduction in failure pressure. The response of glass/epoxy cylinders was compared to impacted carbon reinforced cylinders. Carbon/epoxy is more sensitive to damage but retains higher implosion resistance while carbon/PEEK shows the opposite trend.

  20. Asteroid Composite Tape

    Science.gov (United States)

    1998-07-01

    This is a composite tape showing 10 short segments primarily about asteroids. The segments have short introductory slides, which include brief descriptions about the shots. The segments are: (1) Radar movie of asteroid 1620 Geographos; (2) Animation of the trajectories of Toutatis and Earth (3) Animation of a landing on Toutatis; (4) Simulated encounter of an asteroid with Earth, includes a simulated impact trajectory; (5) An animated overview of the Manrover vehicle; (6) The Near Earth Asteroid Tracking project, includes a photograph of USAF Station in Hawaii, and animation of Earth approaching 4179 Toutatis and the asteroid Gaspara; (7) live video of the anchor tests of the Champoleon anchoring apparatus; (8) a second live video of the Champoleon anchor tests showing anchoring spikes, and collision rings; (9) An animated segment with narration about the Stardust mission with sound, which describes the mission to fly close to a comet, and capture cometary material for return to Earth; (10) live video of the drop test of a Stardust replica from a hot air balloon; this includes sound but is not narrated.

  1. Combinatorics of compositions and words

    CERN Document Server

    Heubach, Silvia

    2009-01-01

    A One-Stop Source of Known Results, a Bibliography of Papers on the Subject, and Novel Research Directions Focusing on a very active area of research in the last decade, Combinatorics of Compositions and Words provides an introduction to the methods used in the combinatorics of pattern avoidance and pattern enumeration in compositions and words. It also presents various tools and approaches that are applicable to other areas of enumerative combinatorics. After a historical perspective on research in the area, the text introduces techniques to solve recurrence relations, including iteration and generating functions. It then focuses on enumeration of basic statistics for compositions. The text goes on to present results on pattern avoidance for subword, subsequence, and generalized patterns in compositions and then applies these results to words. The authors also cover automata, the ECO method, generating trees, and asymptotic results via random compositions and complex analysis. Highlighting both established a...

  2. Machining of Metal Matrix Composites

    CERN Document Server

    2012-01-01

    Machining of Metal Matrix Composites provides the fundamentals and recent advances in the study of machining of metal matrix composites (MMCs). Each chapter is written by an international expert in this important field of research. Machining of Metal Matrix Composites gives the reader information on machining of MMCs with a special emphasis on aluminium matrix composites. Chapter 1 provides the mechanics and modelling of chip formation for traditional machining processes. Chapter 2 is dedicated to surface integrity when machining MMCs. Chapter 3 describes the machinability aspects of MMCs. Chapter 4 contains information on traditional machining processes and Chapter 5 is dedicated to the grinding of MMCs. Chapter 6 describes the dry cutting of MMCs with SiC particulate reinforcement. Finally, Chapter 7 is dedicated to computational methods and optimization in the machining of MMCs. Machining of Metal Matrix Composites can serve as a useful reference for academics, manufacturing and materials researchers, manu...

  3. Wood-based composite materials : panel products, glued-laminated timber, structural composite lumber, and wood-nonwood composite materials

    Science.gov (United States)

    Nicole M. Stark; Zhiyong Cai; Charles Carll

    2010-01-01

    This chapter gives an overview of the general types and composition of wood-based composite products and the materials and processes used to manufacture them. It describes conventional wood-based composite panels and structural composite materials intended for general construction, interior use, or both. This chapter also describes wood–nonwood composites. Mechanical...

  4. Novel coating compositions

    International Nuclear Information System (INIS)

    Kimura, Tadashi; Kobayashi, Juichi; Nakamoto, Hideo.

    1969-01-01

    An acrylic coating composition rapidly hardenable by irradiating with ionizing radiations or light beams is given using hydroxyl group-containing vinyl monomers, polycarboxylic acid anhydrides, epoxy group-containing vinyl monomers and an organic solvent having a boiling point of at least 120 0 C. The process comprises the steps of first and second reactions. The first reaction takes place between one mol of a hydroxyl group of a basic polymer and at least 0.1 mol of polycarboxylic acid anhydride, wherein the basic polymer has a molecular weight ranging from 5,000 to 100,000 and consists of 1-40% by weight of vinyl monomer containing hydroxyl group, at least 30% of (meth)acrylic monomer and other vinyl monomers if required. The second reaction takes place between one mol of hydroxyl plus a carboxyl group of the thus obtained basic polymer and at least 0.1 mol of an epoxy group-containing vinyl monomer to produce a prepolymer. The prepolymer is mixed with a solvent such as ethyl benzene to produce the coating material. The electron beam accelerator energy level may be 0.1-2.0 MeV. In light beam polymerization, benzoin is particularly utilized as an intensifying substance. In one example, a basic polymer is produced by reacting 39 parts of styrene, 37 parts of ethyl acrylate, 24 parts of 2-hydroxyl ethyl acrylate, 4 parts of dimethyl amino ethyl methacrylate and others. A prepolymer is produced by reacting this basic polymer with 30 parts of glycidyl acrylate and others. (Iwakiri, K.)

  5. Composites for Exploration Upper Stage

    Science.gov (United States)

    Fikes, J. C.; Jackson, J. R.; Richardson, S. W.; Thomas, A. D.; Mann, T. O.; Miller, S. G.

    2016-01-01

    The Composites for Exploration Upper Stage (CEUS) was a 3-year, level III project within the Technology Demonstration Missions program of the NASA Space Technology Mission Directorate. Studies have shown that composites provide important programmatic enhancements, including reduced weight to increase capability and accelerated expansion of exploration and science mission objectives. The CEUS project was focused on technologies that best advanced innovation, infusion, and broad applications for the inclusion of composites on future large human-rated launch vehicles and spacecraft. The benefits included near- and far-term opportunities for infusion (NASA, industry/commercial, Department of Defense), demonstrated critical technologies and technically implementable evolvable innovations, and sustained Agency experience. The initial scope of the project was to advance technologies for large composite structures applicable to the Space Launch System (SLS) Exploration Upper Stage (EUS) by focusing on the affordability and technical performance of the EUS forward and aft skirts. The project was tasked to develop and demonstrate critical composite technologies with a focus on full-scale materials, design, manufacturing, and test using NASA in-house capabilities. This would have demonstrated a major advancement in confidence and matured the large-scale composite technology to a Technology Readiness Level 6. This project would, therefore, have bridged the gap for providing composite application to SLS upgrades, enabling future exploration missions.

  6. Assessment of first-year post-graduate residents: usefulness of multiple tools.

    Science.gov (United States)

    Yang, Ying-Ying; Lee, Fa-Yauh; Hsu, Hui-Chi; Huang, Chin-Chou; Chen, Jaw-Wen; Cheng, Hao-Min; Lee, Wen-Shin; Chuang, Chiao-Lin; Chang, Ching-Chih; Huang, Chia-Chang

    2011-12-01

    Objective Structural Clinical Examination (OSCE) usually needs a large number of stations with long test time, which usually exceeds the resources available in a medical center. We aimed to determine the reliability of a combination of Direct Observation of Procedural Skills (DOPS), Internal Medicine in-Training Examination (IM-ITE(®)) and OSCE, and to verify the correlation between the small-scale OSCE+DOPS+IM-ITE(®)-composited scores and 360-degree evaluation scores of first year post-graduate (PGY(1)) residents. Between 2007 January to 2010 January, two hundred and nine internal medicine PGY1 residents completed DOPS, IM-ITE(®) and small-scale OSCE at our hospital. Faculty members completed 12-item 360-degree evaluation for each of the PGY(1) residents regularly. The small-scale OSCE scores correlated well with the 360-degree evaluation scores (r = 0.37, p ITE(®) score with small-scale OSCE+DOPS scores [small-scale OSCE+DOPS+IM-ITE(®)-composited scores] markedly enhanced their correlation with 360-degree evaluation scores (r = 0.85, p ITE(®)-composited scores suggested that both methods were measuring the same quality. Our results showed that the small-scale OSCE, when associated with both the DOPS and IM-ITE(®), could be an important assessment method for PGY(1) residents. Copyright © 2011. Published by Elsevier B.V.

  7. Investigation of Circular Woven Composite Preforms for Composite Pipes

    Directory of Open Access Journals (Sweden)

    Amid Hooman

    2016-06-01

    Full Text Available The main traditional technique for commercial manufacturing of composite pipes is filament winding in which the winding angle and the discontinuity of the structure (caused by starting and ending points of the winding process are two important matters of concern. In the present study, circular woven fabric with its orthogonal net-shaped continuous structure was produced from polyester yarns. Fabric was wet with epoxy and hand lay-up was used to manufacture the composite pipes. Composite pipes were subjected to internal hydrostatic pressure and their burst strength was recorded. In addition, tensile strength of flat laminas was assessed in the warp and weft directions. We estimated and analysed the failure strength of composite pipes using Tresca’s failure criterion and Finite Element (FE modeling. The experimental burst strength was almost 23% more than the FE model and 77% more than the theoretical estimate.

  8. Combustible structural composites and methods of forming combustible structural composites

    Science.gov (United States)

    Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D.; Swank, W. David

    2013-04-02

    Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

  9. High temperature polymer concrete compositions

    Science.gov (United States)

    Fontana, Jack J.; Reams, Walter

    1985-01-01

    This invention is concerned with a polymer concrete composition, which is a two-component composition useful with many bases including metal. Component A, the aggregate composition, is broadly composed of silica, silica flour, portland cement, and acrylamide, whereas Component B, which is primarily vinyl and acrylyl reactive monomers, is a liquid system. A preferred formulation emphasizing the major necessary components is as follows: ______________________________________ Component A: Silica sand 60-77 wt. % Silica flour 5-10 wt. % Portland cement 15-25 wt. % Acrylamide 1-5 wt. % Component B: Styrene 50-60 wt. % Trimethylolpropane 35-40 wt. % trimethacrylate ______________________________________ and necessary initiators, accelerators, and surfactants.

  10. Natural Fiber Composites: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Westman, Matthew P.; Fifield, Leonard S.; Simmons, Kevin L.; Laddha, Sachin; Kafentzis, Tyler A.

    2010-03-07

    The need for renewable fiber reinforced composites has never been as prevalent as it currently is. Natural fibers offer both cost savings and a reduction in density when compared to glass fibers. Though the strength of natural fibers is not as great as glass, the specific properties are comparable. Currently natural fiber composites have two issues that need to be addressed: resin compatibility and water absorption. The following preliminary research has investigated the use of Kenaf, Hibiscus cannabinus, as a possible glass replacement in fiber reinforced composites.

  11. Are quarks and leptons composite

    International Nuclear Information System (INIS)

    Harari, H.

    1982-01-01

    The possibility that quarks and leptons are composite was studied. A line of reasoning was pursued which followed several steps. The standard model was assumed and the need to go beyond it was demonstrated. Different classes of ideas were considered. The notion of compositeness and its general difficulties, mainly the scale problem, were studied. A connection between composite massless fermions and an unbroken chiral symmetry was assumed. A general framework based on hypercolor and a chiral symmetry was established. The general requirements for a candidate model were established. A minimal scheme was found and its successes and failures were studied. (HK)

  12. Compositeness and the Fermi scale

    International Nuclear Information System (INIS)

    Peccei, R.D.

    1984-01-01

    The positive attitude adopted up to now, due to the non-observation of effects of substructure, is that the compositeness scale Λ must be large: Λ > or approx. 1 TeV. Such a large value of Λ gives rise to two theoretical problems which I examine here, namely: 1) What dynamics yields light composite quarks and leptons (msub(f) < < Λ) and 2) What relation does the compositeness scale Λ have with the Fermi scale Λsub(F) = (√2 Gsub(F))sup(-1/2) approx.= 250 GeV. (orig./HSI)

  13. Wear of polymers and composites

    CERN Document Server

    Abdelbary, Ahmed

    2015-01-01

    In the field of tribology, the wear behaviour of polymers and composite materials is considered a highly non-linear phenomenon. Wear of Polymers and Composites introduces fundamentals of polymers and composites tribology. The book suggests a new approach to explore the effect of applied load and surface defects on the fatigue wear behaviour of polymers, using a new tribometer and thorough experiments. It discusses effects of surface cracks, under different static and cyclic loading parameters on wear, and presents an intelligent algorithm, in the form of a neural network, to map the relations

  14. Composites Similarity Analysis Method Based on Knowledge Set in Composites Quality Control

    OpenAIRE

    Li Haifeng

    2016-01-01

    Composites similarity analysis is an important link of composites review, it can not only to declare composites review rechecking, still help composites applicants promptly have the research content relevant progress and avoid duplication. This paper mainly studies the composites similarity model in composites review. With the actual experience of composites management, based on the author’s knowledge set theory, paper analyzes deeply knowledge set representation of composites knowledge, impr...

  15. Methods and compositions using calcium carbonate

    Science.gov (United States)

    Constantz, Brent R [Portola Valley, CA; Farsad, Kasra [San Jose, CA; Camire, Chris [San Jose, CA; Chen, Irvin [San Jose, CA

    2011-04-12

    Provided herein are compositions and methods including hydraulic cement, supplementary cementitious material, and/or self-cementing material. Methods for making the compositions and using the compositions are provided.

  16. Biomass Compositional Analysis Laboratory Procedures | Bioenergy | NREL

    Science.gov (United States)

    Biomass Compositional Analysis Laboratory Procedures Biomass Compositional Analysis Laboratory Procedures NREL develops laboratory analytical procedures (LAPs) for standard biomass analysis. These procedures help scientists and analysts understand more about the chemical composition of raw biomass

  17. Methods and compositions using calcium carbonate

    Science.gov (United States)

    Constantz, Brent R [Portola Valley, CA; Farsad, Kasra [San Jose, CA; Camire, Chris [San Jose, CA; Chen, Irvin [Santa Clara, CA; Ginder-Vogel, Matthew [Los Gatos, CA; Fernandez, Miguel [San Jose, CA

    2012-05-15

    Provided herein are compositions and methods including hydraulic cement, supplementary cementitious material, and/or self-cementing material. Methods for making the compositions and using the compositions are provided.

  18. Household composition and psychological health

    DEFF Research Database (Denmark)

    Joensen, Lene Eide; Willaing, Ingrid; Holt, Richard I G

    2017-01-01

    AIMS: 1) To explore the effect of household composition on the psychological health of adults with diabetes by comparing those living with other adult(s) including a partner with those living with neither partner nor other adult(s); 2) to examine potential mediation of social support...... in the association between household composition and psychological health. METHODS: The study is part of the DAWN2 study conducted in 17 countries. The population comprised 8596 people with diabetes (PWD). Multiple regression models (linear and binary) were applied. RESULTS: People living with 'other adult...... to the other household composition groups. The association between household composition and psychological health was not mediated by diabetes-specific social support. CONCLUSIONS: The study indicates the psychological vulnerability of respondents living without a partner but with other adult(s). Appropriate...

  19. Layered plasma polymer composite membranes

    Science.gov (United States)

    Babcock, Walter C.

    1994-01-01

    Layered plasma polymer composite fluid separation membranes are disclosed, which comprise alternating selective and permeable layers for a total of at least 2n layers, where n is .gtoreq.2 and is the number of selective layers.

  20. Erosion-resistant composite material

    Science.gov (United States)

    Finch, C.B.; Tennery, V.J.; Curlee, R.M.

    A highly erosion-resistant composite material is formed of chemical vapor-deposited titanium diboride on a sintered titanium diboride-nickel substrate. This material may be suitable for use in cutting tools, coal liquefaction systems, etc.

  1. Fatigue life prediction in composites

    CSIR Research Space (South Africa)

    Huston, RJ

    1994-01-01

    Full Text Available Because of the relatively large number of possible failure mechanisms in fibre reinforced composite materials, the prediction of fatigue life in a component is not a simple process. Several mathematical and statistical models have been proposed...

  2. 1-3 Composites Study

    National Research Council Canada - National Science Library

    Gabrielson, Thomas B

    2003-01-01

    ...) In a transducer in which the active material is sandwiched between mass elements, the filler in a 1-3 composite degrades performance with respect to an unfilled array of piezoelectric rods. (3...

  3. Composition operators with weak hyponormality

    Science.gov (United States)

    Burnap, Charles; Jung, Il Bong

    2008-01-01

    There are many operator classes that are weaker than p-hyponormal. These include p-quasihyponormal, absolute p-paranormal, p-paranormal, normaloid, and spectraloid. In this note, we discuss measure theoretic composition operators in these classes.

  4. Composite materials for aircraft structures

    National Research Council Canada - National Science Library

    Baker, A. A; Dutton, Stuart; Kelly, Donald

    2004-01-01

    ... materials for aircraft structures / Alan Baker, Stuart Dutton, and Donald Kelly- 2nd ed. p. cm. - (Education series) Rev. ed. of: Composite materials for aircraft structures / edited by B. C. Hos...

  5. Genetic Homogenization of Composite Materials

    Directory of Open Access Journals (Sweden)

    P. Tobola

    2009-04-01

    Full Text Available The paper is focused on numerical studies of electromagnetic properties of composite materials used for the construction of small airplanes. Discussions concentrate on the genetic homogenization of composite layers and composite layers with a slot. The homogenization is aimed to reduce CPU-time demands of EMC computational models of electrically large airplanes. First, a methodology of creating a 3-dimensional numerical model of a composite material in CST Microwave Studio is proposed focusing on a sufficient accuracy of the model. Second, a proper implementation of a genetic optimization in Matlab is discussed. Third, an association of the optimization script and a simplified 2-dimensional model of the homogeneous equivalent model in Comsol Multiphysics is proposed considering EMC issues. Results of computations are experimentally verified.

  6. The 4D Composite Higgs

    CERN Document Server

    De Curtis, Stefania; Tesi, Andrea

    2012-01-01

    We propose a four dimensional description of Composite Higgs Models which represents a complete framework for the physics of the Higgs as a pseudo-Nambu-Goldstone boson. Our setup captures all the relevant features of 5D models and more in general of composite Higgs models with partial compositeness. We focus on the minimal scenario where we include a single multiplet of resonances of the composite sector, as these will be the only degrees of freedom which might be accessible at the LHC. This turns out to be sufficient to compute the effective potential and derive phenomenological consequences of the theory. Moreover our simplified approach is well adapted to simulate these models at the LHC. We also consider the impact of non-minimal terms in the effective lagrangian which do not descend from a 5D theory and could be of phenomenological relevance, for example contributing to the S-parameter.

  7. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  8. Composition operators on function spaces

    CERN Document Server

    Singh, RK

    1993-01-01

    This volume of the Mathematics Studies presents work done on composition operators during the last 25 years. Composition operators form a simple but interesting class of operators having interactions with different branches of mathematics and mathematical physics. After an introduction, the book deals with these operators on Lp-spaces. This study is useful in measurable dynamics, ergodic theory, classical mechanics and Markov process. The composition operators on functional Banach spaces (including Hardy spaces) are studied in chapter III. This chapter makes contact with the theory of analytic functions of complex variables. Chapter IV presents a study of these operators on locally convex spaces of continuous functions making contact with topological dynamics. In the last chapter of the book some applications of composition operators in isometries, ergodic theory and dynamical systems are presented. An interesting interplay of algebra, topology, and analysis is displayed. This comprehensive and up-to-date stu...

  9. Water-bearing explosive compositions

    Energy Technology Data Exchange (ETDEWEB)

    Gay, G M

    1970-12-21

    An explosive water-bearing composition, with high detonation velocity, comprises a mixture of (1) an inorganic oxidizer salt; (2) nitroglycerine; (3) nitrocellulose; (4) water; and (5) a water thickening agent. (11 claims)

  10. Bulk metallic glass matrix composites

    International Nuclear Information System (INIS)

    Choi-Yim, H.; Johnson, W.L.

    1997-01-01

    Composites with a bulk metallic glass matrix were synthesized and characterized. This was made possible by the recent development of bulk metallic glasses that exhibit high resistance to crystallization in the undercooled liquid state. In this letter, experimental methods for processing metallic glass composites are introduced. Three different bulk metallic glass forming alloys were used as the matrix materials. Both ceramics and metals were introduced as reinforcement into the metallic glass. The metallic glass matrix remained amorphous after adding up to a 30 vol% fraction of particles or short wires. X-ray diffraction patterns of the composites show only peaks from the second phase particles superimposed on the broad diffuse maxima from the amorphous phase. Optical micrographs reveal uniformly distributed particles in the matrix. The glass transition of the amorphous matrix and the crystallization behavior of the composites were studied by calorimetric methods. copyright 1997 American Institute of Physics

  11. Compositeness of quarks and leptons

    International Nuclear Information System (INIS)

    Peskin, M.E.

    1981-01-01

    I review along grand lines the theoretical ideas associated with the notion that quarks and leptons are composite. I first discuss various constituent pictures which have been proposed to account for the quantum numbers of the observed quarks and leptons, a study I call the Quantum Numerology. I then discuss some new theoretical developments of the past two years which bear on the subject of composite fermions and which make plausible (or rule out) some of the major dynamical assumptions of these constituent models. Finally, I discuss the consequences of the compositeness of quarks and leptons by setting up a series of scenarios for this compositeness and exploring, for each scenario, its experimental implications. (orig./HSI)

  12. Autonomic Fuselet Specification and Composition

    National Research Council Canada - National Science Library

    Mills, Peter H

    2006-01-01

    ... model for its business logic, and to perform workflow composition from a goal and specifications to executable model in a manner that enables feedback mechanisms that can assess and adapt the process...

  13. Glass-Graphite Composite Materials

    International Nuclear Information System (INIS)

    Mayzan, M.Z.H.; Lloyd, J.W.; Heath, P.G.; Stennett, M.C.; Hyatt, N.C.; Hand, R.J.

    2016-01-01

    A summary is presented of investigations into the potential of producing glass-composite materials for the immobilisation of graphite or other carbonaceous materials arising from nuclear power generation. The methods are primarily based on the production of base glasses which are subsequently sintered with powdered graphite or simulant TRISO particles. Consideration is also given to the direct preparation of glass-graphite composite materials using microwave technology. Production of dense composite wasteforms with TRISO particles was more successful than with powdered graphite, as wasteforms containing larger amounts of graphite were resistant to densification and the glasses tried did not penetrate the pores under the pressureless conditions used. Based on the results obtained it is concluded that the production of dense glassgraphite composite wasteforms will require the application of pressure. (author)

  14. TIGER NUT (CYPERUS ESCULENTUS): COMPOSITION ...

    African Journals Online (AJOL)

    DR. AMINU

    This paper is a review on little history and the composition of Tigernut ranging from proximate, mineral and amino ..... thought to be beneficial to diabetics and those seeking to reduce ... (Cyperus esculentus) souced from a market in Ogbomoso ...

  15. Glycerine Treated Nanofibrillated Cellulose Composites

    Directory of Open Access Journals (Sweden)

    Esra Erbas Kiziltas

    2016-01-01

    Full Text Available Glycerine treated nanofibrillated cellulose (GNFC was prepared by mixing aqueous nanofibrillated cellulose (NFC suspensions with glycerine. Styrene maleic anhydride (SMA copolymer composites with different loadings of GNFC were prepared by melt compounding followed by injection molding. The incorporation of GNFC increased tensile and flexural modulus of elasticity of the composites. Thermogravimetric analysis showed that as GNFC loading increased, the thermal stability of the composites decreased marginally. The incorporation of GNFC into the SMA copolymer matrix resulted in higher elastic modulus (G′ and shear viscosities than the neat SMA copolymer, especially at low frequencies. The orientation of rigid GNFC particles in the composites induced a strong shear thinning behavior with an increase in GNFC loading. The decrease in the slope of elastic modulus with increasing GNFC loading suggested that the microstructural changes of the polymer matrix can be attributed to the incorporation of GNFC. Scanning electron microscopy (SEM images of fracture surfaces show areas of GNFC agglomerates in the SMA matrix.

  16. Compositional changes during ion bombardment

    International Nuclear Information System (INIS)

    Rehn, L.E.

    1988-09-01

    Ion irradiation initiates several processes that can alter the composition of the target. This presentation provides an overview of our current understanding of these kinetics processes, which include implantation, sputtering, displacement mixing, radiation-enhanced diffusion, and radiation-induced segregation. The latter two effects can alter the target composition to depths that are substantially greater than the projected ion range. 45 refs., 8 figs

  17. The Chemical Composition of Mercury

    OpenAIRE

    Nittler, Larry R.; Chabot, Nancy L.; Grove, Timothy L.; Peplowski, Patrick N.

    2017-01-01

    The chemical composition of a planetary body reflects its starting conditions modified by numerous processes during its formation and geological evolution. Measurements by X-ray, gamma-ray, and neutron spectrometers on the MESSENGER spacecraft revealed Mercury's surface to have surprisingly high abundances of the moderately volatile elements sodium, sulfur, potassium, chlorine, and thorium, and a low abundance of iron. This composition rules out some formation models for which high temperatur...

  18. Thematic Composition and Idiom Variation

    Directory of Open Access Journals (Sweden)

    Cserép Attila

    2017-11-01

    Full Text Available The Corpus of Contemporary American English (COCA has been studied to retrieve variant forms of semantically decomposable idioms that have no thematic composition for the purpose of determining whether thematic composition is a necessary criterion for idiom variation as claimed by Horn (2003. The syntactic variants searched for include passive, raising, tough-movement, relative clauses and wh-questions. Horn’s (2003 hypothesis is not fully confirmed, as some variation has been found.

  19. Maximally Symmetric Composite Higgs Models.

    Science.gov (United States)

    Csáki, Csaba; Ma, Teng; Shu, Jing

    2017-09-29

    Maximal symmetry is a novel tool for composite pseudo Goldstone boson Higgs models: it is a remnant of an enhanced global symmetry of the composite fermion sector involving a twisting with the Higgs field. Maximal symmetry has far-reaching consequences: it ensures that the Higgs potential is finite and fully calculable, and also minimizes the tuning. We present a detailed analysis of the maximally symmetric SO(5)/SO(4) model and comment on its observational consequences.

  20. Advanced technology composite aircraft structures

    Science.gov (United States)

    Ilcewicz, Larry B.; Walker, Thomas H.

    1991-01-01

    Work performed during the 25th month on NAS1-18889, Advanced Technology Composite Aircraft Structures, is summarized. The main objective of this program is to develop an integrated technology and demonstrate a confidence level that permits the cost- and weight-effective use of advanced composite materials in primary structures of future aircraft with the emphasis on pressurized fuselages. The period from 1-31 May 1991 is covered.

  1. Composite Electrodes for Electrochemical Supercapacitors

    OpenAIRE

    Li, Jun; Yang, QuanMin; Zhitomirsky, Igor

    2010-01-01

    Abstract Manganese dioxide nanofibers with length ranged from 0.1 to 1 μm and a diameter of about 4–6 nm were prepared by a chemical precipitation method. Composite electrodes for electrochemical supercapacitors were fabricated by impregnation of the manganese dioxide nanofibers and multiwalled carbon nanotubes (MWCNT) into porous Ni plaque current collectors. Obtained composite electrodes, containing 85% of manganese dioxide and 15 mass% of MWCNT, as a conductive additive, with to...

  2. Composite interlayer for diffusion bonding

    International Nuclear Information System (INIS)

    1976-01-01

    A ductile interlayer is described, which is useful for transient liquid phase diffusion bonding of metallic articles; the interlayer consisting of a melting point depressant and a plurality of ductile lamellae which are free from carbides, aluminides and borides. The composition and fabrication of the lamellae, and the process for bonding the metallic articles, depend on the composition of the metals to be bonded, and are exemplified in the specification. (U.K.)

  3. Ballistic impact on composite armour

    OpenAIRE

    Bourke, P

    2007-01-01

    Armoured vehicles in current military service are requiring ever more protection to enable them to carry out their mission in a safe, effective manner. This requirement is driving vehicle weight up to such an extent that the logistics of vehicle transport is becoming increasingly difficult. Composite materials are an important material group whose high specific properties can enable structures to be manufactured for a far lower weight than might otherwise be possible. Composite...

  4. Composite materials for cryogenic structures

    International Nuclear Information System (INIS)

    Kasen, M.B.

    1978-01-01

    The paper is concerned with the composition, mechanical properties and capabilities of various types of composite materials for cryogenic structures. Attention is given to high-pressure plastic laminates, low-pressure plastic laminates, metal-matrix laminates, and aggregates (low-temperature concretes). The ability of these materials to match the strength and modulus of stainless steels suggests that their usage will substantially increase as alloying elements become scarce and more expensive

  5. Immigration, Wages, and Compositional Amenities

    OpenAIRE

    David Card; Christian Dustmann; Ian Preston

    2009-01-01

    Economists are often puzzled by the stronger public opposition to immigration than trade, since the two policies have symmetric effects on wages. Unlike trade, however, immigration changes the composition of the local population, imposing potential externalities on natives. While previous studies have focused on fiscal spillovers, a broader class of externalities arise because people value the "compositional amenities" associated with the characteristics of their neighbors and co-workers. In ...

  6. Method for preparing ceramic composite

    Science.gov (United States)

    Alexander, K.B.; Tiegs, T.N.; Becher, P.F.; Waters, S.B.

    1996-01-09

    A process is disclosed for preparing ceramic composite comprising blending TiC particulates, Al{sub 2}O{sub 3} particulates and nickel aluminide and consolidating the mixture at a temperature and pressure sufficient to produce a densified ceramic composite having fracture toughness equal to or greater than 7 MPa m{sup 1/2}, a hardness equal to or greater than 18 GPa. 5 figs.

  7. LIQUID METAL COMPOSITIONS CONTAINING URANIUM

    Science.gov (United States)

    Teitel, R.J.

    1959-04-21

    Liquid metal compositions containing a solid uranium compound dispersed therein is described. Uranium combines with tin to form the intermetallic compound USn/sub 3/. It has been found that this compound may be incorporated into a liquid bath containing bismuth and lead-bismuth components, if a relatively small percentage of tin is also included in the bath. The composition has a low thermal neutron cross section which makes it suitable for use in a liquid metal fueled nuclear reactor.

  8. Photocatalytic/Magnetic Composite Particles

    Science.gov (United States)

    Wu, Chang-Yu; Goswami, Yogi; Garretson, Charles; Andino, Jean; Mazyck, David

    2007-01-01

    Photocatalytic/magnetic composite particles have been invented as improved means of exploiting established methods of photocatalysis for removal of chemical and biological pollutants from air and water. The photocatalytic components of the composite particles are formulated for high levels of photocatalytic activity, while the magnetic components make it possible to control the movements of the particles through the application of magnetic fields. The combination of photocatalytic and magnetic properties can be exploited in designing improved air- and water treatment reactors.

  9. COMPOSITE SOLUTIONS IN RAILROAD ENGINEERING

    Directory of Open Access Journals (Sweden)

    Panfilova Marina Ivanovna

    2012-10-01

    Full Text Available Present-day methods of recovery of used wooden railway ties, including burial, chemical neutralization, gasification and subsequent burning, utilization in the capacity of composite materials, are expensive and unsafe for the environment. The authors propose a new method of their utilization. Ash generated in the course of their burning may replace a portion of cement in composite solutions and act as an additive to grouting mortars designated for the filling of the annulus space of manifold tunnels. The chemical composition of the ash was identified by the x-ray method applied to three samples taken during various periods of time from out of a dry-type dust collector. The level of human health/environmental hazard of the ash is based on its chemical composition. Changes in the rheological properties of composite solutions that contained concrete fractions, various ratios of ash, and 5% of liquid glass were studied in the course of the research. The experiments have proven that in the event of replacement of 20% of cement by ash, the strength of the composite solution is approximately the same as the one of the benchmark sample; therefore, this ash content ratio is deemed acceptable. The finding demonstrate that the ash has no toxic effect, and the ecological safety of this solution is thus confirmed. The authors have proven that 20% of cement may be replaced by the ash generated in the course of burning of waste railway ties.

  10. The compositional classification of chondrites

    International Nuclear Information System (INIS)

    Kallemeyn, G.W.; Wasson, J.T.; California Univ., Los Angeles; California Univ., Los Angeles

    1985-01-01

    Six specimens of unusual chondritic materials were analyzed by neutron activation for 30 elements in order to assess their degree of chondritic compositional pristinity and to search for evidence of genetic links to other chondrites. Five have highly recrystallized textures: the other, the Cumberland Falls chondrite, has suffered minor metamorphic recrystallization. Acapulco and Allan Hills A77081, are closely related and have subpristine compositions; they are more distantly related to Enon which has an altered composition. Udei Station appears to be a IAB meteorite even though its FeO/(FeO + MgO) ratio is slightly above the IAB field. The highly weathered meteorite Tierra Blanca is closely related to IAB but has a delta 18 O value 5 standard deviations higher than the IAB mean, and is designated ungrouped. Udei Station and Tierra Blanca have altered compositions; rare earth element patterns indicate loss of a phosphate phase. The elemental composition of the Cumberland Falls chondrite is virtually identical to that of LL chondrites, and its O-isotope composition is closely similar to those of some unequilibrated ordinary chondrites including LL Semarkona. The FeO/(FeO + MgO) ratios in its olivine are generally much lower than those in pyroxene. (author)

  11. Strain-Detecting Composite Materials

    Science.gov (United States)

    Wallace, Terryl A. (Inventor); Smith, Stephen W. (Inventor); Piascik, Robert S. (Inventor); Horne, Michael R. (Inventor); Messick, Peter L. (Inventor); Alexa, Joel A. (Inventor); Glaessgen, Edward H. (Inventor); Hailer, Benjamin T. (Inventor)

    2016-01-01

    A composite material includes a structural material and a shape-memory alloy embedded in the structural material. The shape-memory alloy changes crystallographic phase from austenite to martensite in response to a predefined critical macroscopic average strain of the composite material. In a second embodiment, the composite material includes a plurality of particles of a ferromagnetic shape-memory alloy embedded in the structural material. The ferromagnetic shape-memory alloy changes crystallographic phase from austenite to martensite and changes magnetic phase in response to the predefined critical macroscopic average strain of the composite material. A method of forming a composite material for sensing the predefined critical macroscopic average strain includes providing the shape-memory alloy having an austenite crystallographic phase, changing a size and shape of the shape-memory alloy to thereby form a plurality of particles, and combining the structural material and the particles at a temperature of from about 100-700.degree. C. to form the composite material.

  12. Bioactive composite for keratoprosthesis skirt.

    Science.gov (United States)

    Laattala, Kaisa; Huhtinen, Reeta; Puska, Mervi; Arstila, Hanna; Hupa, Leena; Kellomäki, Minna; Vallittu, Pekka K

    2011-11-01

    In this study, the fabrication and properties of a synthetic keratoprosthesis skirt for use in osteo-odonto-keratoprosthesis (OOKP) surgery are discussed. In the search for a new material concept, bioactive glass and polymethyl methacrylate (PMMA)-based composites were prepared. Three different bioactive glasses (i.e. 45S5, S53P4 and 1-98) and one slowly resorbing glass, FL107, with two different forms (i.e. particles and porous glass structures) were employed in the fabrication of specimens. In in vitro studies, the dissolution behaviour in simulated aqueous humour, compressive properties, and pore formation of the composites were investigated. According to the results, FL107 dissolved very slowly (2.4% of the initial glass content in three weeks); thus, the pore formation of the FL107 composite was also observed to be restricted. The dissolution rates of the bioactive glass-PMMA composites were greater (12%-17%). These faster dissolving bioactive glass particles caused some porosity on the outermost surfaces of the composite. The slight surface porosity was also confirmed by a decrease in compressive properties. During six weeks' in vitro dissolution, the compressive strength of the test specimens containing particles decreased by 22% compared to values in dry conditions (90-107 MPa). These results indicate that the bioactive composites could be stable synthetic candidates for a keratoprosthesis skirt in the treatment of severely damaged or diseased cornea. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. How real are composite fermions?

    International Nuclear Information System (INIS)

    Kang, W.; Stormer, H.L.; Pfeiffer, L.N.; Baldwin, K.W.; West, K.W.

    1995-01-01

    A new picture of fractional quantum Hall effect (FQHE) in terms of a novel particle called composite fermion has emerged recently. A composite fermion is a composite of two flux quanta which are effectively bound to an electron as a result of electron-electron interaction. A system of electrons at half-filled Landau level can be transformed to an equivalent system of composite fermions at zero effective magnetic field with a distinct Fermi surface. The FQHE is then viewed as the integral quantum Hall effect of composite fermions away from half-filling. In order to test for these new particles, we have studied transport of anti-dot superlattices in a two-dimensional electron gas. At low magnetic fields electron transport exhibits well-known resonances at fields where the classical cyclotron orbit becomes commensurate with the anti-dot lattice. At half-filling we observe the same dimensional resonances. This establishes the ''semi-classical'' behavior of composite fermions. (orig.)

  14. Titanium Matrix Composite Pressure Vessel, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — For over 15 years, FMW Composite Systems has developed Metal Matrix Composite manufacturing methodologies for fabricating silicon-carbide-fiber-reinforced titanium...

  15. Advanced Manufacturing Technologies (AMT): Composites Integrated Modeling

    Data.gov (United States)

    National Aeronautics and Space Administration — The Composites Integrated Modeling (CIM) Element developed low cost, lightweight, and efficient composite structures, materials and manufacturing technologies with...

  16. INFRARED GLOBAL GEOSTATIONARY COMPOSITE V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The National Center for Environmental Prediction/Aviation Weather Center Infrared Global Geostationary Composite data set contains global composite images from the...

  17. Salt Composition Derived from Veazey Composition by Thermodynamic Modeling and Predicted Composition of Drum Contents

    Energy Technology Data Exchange (ETDEWEB)

    Weisbrod, Kirk Ryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Veirs, Douglas Kirk [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Funk, David John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clark, David Lewis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-11

    This report describes the derivation of the salt composition from the Veazey salt stream analysis. It also provides an estimate of the proportions of the kitty litter, nitrate salt and neutralizer that was contained in drum 68660. While the actinide content of waste streams was judiciously followed in the 1980s in TA-55, no record of the salt composition could be found. Consequently, a salt waste stream produced from 1992 to 1994 and reported by Gerry Veazey provided the basis for this study. While chemical analysis of the waste stream was highly variable, an average analysis provided input to the Stream Analyzer software to calculate a composition for a concentrated solid nitrate salt and liquid waste stream. The calculation predicted the gas / condensed phase compositions as well as solid salt / saturated liquid compositions. The derived composition provides an estimate of the nitrate feedstream to WIPP for which kinetic measurements can be made. The ratio of salt to Swheat in drum 68660 contents was estimated through an overall mass balance on the parent and sibling drums. The RTR video provided independent confirmation concerning the volume of the mixture. The solid salt layer contains the majority of the salt at a ratio with Swheat that potentially could become exothermic.

  18. Salt Composition Derived from Veazey Composition by Thermodynamic Modeling and Predicted Composition of Drum Contents

    International Nuclear Information System (INIS)

    Weisbrod, Kirk Ryan; Veirs, Douglas Kirk; Funk, David John; Clark, David Lewis

    2016-01-01

    This report describes the derivation of the salt composition from the Veazey salt stream analysis. It also provides an estimate of the proportions of the kitty litter, nitrate salt and neutralizer that was contained in drum 68660. While the actinide content of waste streams was judiciously followed in the 1980s in TA-55, no record of the salt composition could be found. Consequently, a salt waste stream produced from 1992 to 1994 and reported by Gerry Veazey provided the basis for this study. While chemical analysis of the waste stream was highly variable, an average analysis provided input to the Stream Analyzer software to calculate a composition for a concentrated solid nitrate salt and liquid waste stream. The calculation predicted the gas / condensed phase compositions as well as solid salt / saturated liquid compositions. The derived composition provides an estimate of the nitrate feedstream to WIPP for which kinetic measurements can be made. The ratio of salt to Swheat in drum 68660 contents was estimated through an overall mass balance on the parent and sibling drums. The RTR video provided independent confirmation concerning the volume of the mixture. The solid salt layer contains the majority of the salt at a ratio with Swheat that potentially could become exothermic.

  19. Natural Composites: Cellulose Fibres and the related Performance of Composites

    DEFF Research Database (Denmark)

    Lilholt, Hans; Madsen, Bo

    2014-01-01

    Biobased materials are becoming of increasing interest as potential structural materials for the future. A useful concept in this context is the fibre reinforcement of materials by stiff and strong fibres. The biobased resources can contribute with cellulose fibres and biopolymers. This offers th...... in stiffness, on the packing ability of cellulose fibres and the related maximum fibre volume fraction in composites, on the moisture sorption of cellulose fibres and the related mass increase and (large) hygral strains induced, and on the mechanical performance of composites....

  20. Creep of high temperature composites

    International Nuclear Information System (INIS)

    Sadananda, K.; Feng, C.R.

    1993-01-01

    High temperature creep deformation of composites is examined. Creep of composites depends on the interplay of many factors. One of the basic issues in the design of the creep resistant composites is the ability to predict their creep behavior from the knowledge of the creep behavior of the individual components. In this report, the existing theoretical models based on continuum mechanics principles are reviewed. These models are evaluated using extensive experimental data on molydisilicide-silicon carbide composites obtained by the authors. The analysis shows that the rule of mixture based on isostrain and isostress provides two limiting bounds wherein all other theoretical predictions fall. For molydisilicide composites, the creep is predominantly governed by the creep of the majority phase, i.e. the matrix with fibers deforming elastically. The role of back stresses both on creep rates and activation energies are shown to be minimum. Kinetics of creep in MoSi 2 is shown to be controlled by the process of dislocation glide with climb involving the diffusion of Mo atoms

  1. Producing ceramic laminate composites by EPD

    International Nuclear Information System (INIS)

    Nicholson, P.S.; Sarkar, P.; Datta, S.

    1996-01-01

    The search for tough structural ceramics to operate at high temperatures in hostile environments has led to the development of ceramic composites. This class of material includes laminar ceramic-ceramic composites, continuous-fiber-reinforced ceramic composites and functionally graded materials. The present authors developed electrophoretic deposition (EPD) to synthesize lamellar, fiber-reinforced and functionally graded composites. This paper briefly describes the synthesis and characterization of these EPD composites and introduces a novel class of lamellar composites with nonplanar layers. The synthesis of the latter demonstrates the facility of the EPD process for the synthesis of ceramic composites. The process is totally controllable via suspension concentration, deposition current, voltage and time

  2. Radiation-curable coating composition

    International Nuclear Information System (INIS)

    Mibae, Jiro; Kawamura, Hiroshi; Takahashi, Masao.

    1970-01-01

    A radiation-curable coating composition, suitable for metal precoating, is provided. The composition is prepared by mixing 50 to 90 parts of a long chain fatty acid ester (A) with 10 to 50 parts of monomer (B) which is copolymerizable with (A). (A) is prepared by reacting a dimer acid (particularly the dimer of linolenic acid) with hydroxyalkyl methacrylate or glycidyl methacrylate. Upon irradiation with electron beams (0.1 to 3 MeV) the composition cures to yield a coating of high adhesion, impact resistance and bending resistance. In one example, 100 g of dimer acid (Versadime 216, manufactured by General Mills) was esterified with 50 g of 2-hydroxyethyl methacrylate. A zinc plated iron plate was coated with the product and irradiated with electron beams (2 Mrad). Pencil hardness was F; adhesion 0: impact resistance (Du Pont) 1 kg x 30 cm; bending resistance 2T. (Kaichi, S.)

  3. Compositional Reasoning in Early Childhood.

    Directory of Open Access Journals (Sweden)

    Steven Piantadosi

    Full Text Available Compositional "language of thought" models have recently been proposed to account for a wide range of children's conceptual and linguistic learning. The present work aims to evaluate one of the most basic assumptions of these models: children should have an ability to represent and compose functions. We show that 3.5-4.5 year olds are able to predictively compose two novel functions at significantly above chance levels, even without any explicit training or feedback on the composition itself. We take this as evidence that children at this age possess some capacity for compositionality, consistent with models that make this ability explicit, and providing an empirical challenge to those that do not.

  4. Durability of aircraft composite materials

    Science.gov (United States)

    Dextern, H. B.

    1982-01-01

    Confidence in the long term durability of advanced composites is developed through a series of flight service programs. Service experience is obtained by installing secondary and primary composite components on commercial and military transport aircraft and helicopters. Included are spoilers, rudders, elevators, ailerons, fairings and wing boxes on transport aircraft and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on helicopters. Materials included in the evaluation are boron/epoxy, Kevlar/epoxy, graphite/epoxy and boron/aluminum. Inspection, maintenance, and repair results for the components in service are reported. The effects of long term exposure to laboratory, flight, and outdoor environmental conditions are reported for various composite materials. Included are effects of moisture absorption, ultraviolet radiation, and aircraft fuels and fluids.

  5. Composite media for ion processing

    Science.gov (United States)

    Mann, Nick R [Blackfoot, ID; Wood, Donald J [Peshastin, WA; Todd, Terry A [Aberdeen, ID; Sebesta, Ferdinand [Prague, CZ

    2009-12-08

    Composite media, systems, and devices for substantially removing, or otherwise processing, one or more constituents of a fluid stream. The composite media comprise a plurality of beads, each having a matrix substantially comprising polyacrylonitrile (PAN) and supporting one or more active components which are effective in removing, by various mechanisms, one or more constituents from a fluid stream. Due to the porosity and large surface area of the beads, a high level of contact is achieved between composite media of the present invention and the fluid stream being processed. Further, the homogeneity of the beads facilitates use of the beads in high volume applications where it is desired to effectively process a large volume of flow per unit of time.

  6. Partially composite Goldstone Higgs boson

    DEFF Research Database (Denmark)

    Alanne, Tommi; Franzosi, Diogo Buarque; Frandsen, Mads T.

    2017-01-01

    We consider a model of dynamical electroweak symmetry breaking with a partially composite Goldstone Higgs boson. The model is based on a strongly interacting fermionic sector coupled to a fundamental scalar sector via Yukawa interactions. The SU(4)×SU(4) global symmetry of these two sectors...... is broken to a single SU(4) via Yukawa interactions. Electroweak symmetry breaking is dynamically induced by condensation due to the strong interactions in the new fermionic sector which further breaks the global symmetry SU(4)→Sp(4). The Higgs boson arises as a partially composite state which is an exact...... Goldstone boson in the limit where SM interactions are turned off. Terms breaking the SU(4) global symmetry explicitly generate a mass for the Goldstone Higgs boson. The model realizes in different limits both (partially) composite Higgs and (bosonic) technicolor models, thereby providing a convenient...

  7. Optimization of Laminated Composite Structures

    DEFF Research Database (Denmark)

    Henrichsen, Søren Randrup

    of the contributions of the PhD project are included in the second part of the thesis. Paper A presents a framework for free material optimization where commercially available finite element analysis software is used as analysis tool. Robust buckling optimization of laminated composite structures by including...... allows for a higher degree of tailoring of the resulting material. To enable better utilization of the composite materials, optimum design procedures can be used to assist the engineer. This PhD thesis is focused on developing numerical methods for optimization of laminated composite structures...... nonlinear analysis of structures, buckling and post-buckling analysis of structures, and formulations for optimization of structures considering stiffness, buckling, and post-buckling criteria. Lastly, descriptions, main findings, and conclusions of the papers are presented. The papers forming the basis...

  8. Maintaining protein composition in cilia.

    Science.gov (United States)

    Stephen, Louise A; Elmaghloob, Yasmin; Ismail, Shehab

    2017-12-20

    The primary cilium is a sensory organelle that is vital in regulating several signalling pathways. Unlike most organelles cilia are open to the rest of the cell, not enclosed by membranes. The distinct protein composition is crucial to the function of cilia and many signalling proteins and receptors are specifically concentrated within distinct compartments. To maintain this composition, a mechanism is required to deliver proteins to the cilium whilst another must counter the entropic tendency of proteins to distribute throughout the cell. The combination of the two mechanisms should result in the concentration of ciliary proteins to the cilium. In this review we will look at different cellular mechanisms that play a role in maintaining the distinct composition of cilia, including regulation of ciliary access and trafficking of ciliary proteins to, from and within the cilium.

  9. Galactic cosmic ray iron composition

    International Nuclear Information System (INIS)

    Scherzer, R.; Enge, W.; Beaujean, R.

    1980-11-01

    We have studied the isotopic compostition of galactic cosmic ray iron in the energy interval 500-750 MeV/nucleon with a visual track detector system consisting of nuclear emulsion and cellulose-nitrate platic. Stopping iron nuclei were identified from ionization - range measurements in the two detector parts. Cone lengths were measured in the plastic sheets and the residual ranges of the particles were measured in plastic and in emulsion. We have determined the mass of 17 iron nuclei with an uncertainty of about 0.3 amu. The isotopic composition at the detector level was found to be 52 Fe: 53 Fe: 54 Fe: 55 Fe: 56 Fe: 57 Fe: 58 Fe = 0:1: 4:3:8:1:0. These numbers are not in conflict with the assumption that the isotopic composition of cosmic ray iron at the source is similar to the solar system composition. (author)

  10. Identification of computer-generated facial composites.

    Science.gov (United States)

    Kovera, M B; Penrod, S D; Pappas, C; Thill, D L

    1997-04-01

    Two studies examined the effectiveness of the Mac-a-Mug Pro, a computerized facial composite production system. In the first study, college freshmen prepared from memory composites of other students and faculty from their former high schools. Other students who had attended the same high schools could not recognize the composites of either students or faculty members when the composites of individuals known to them (n = 10) were mixed with composites of a large number (n = 40) of strangers. Neither preparer familiarity with the target, preparer-assessed composite quality, nor viewer familiarity predicted composite recognition. Study 2 indicated that naive witnesses who viewed the composites could not select the people depicted in the composites from photo lineups (1 target and 4 foils). The results raise questions about the efficacy of composite systems as tools to promote recognition of suspects in criminal contexts.

  11. Formation of tough composite joints

    International Nuclear Information System (INIS)

    Brun, M.K.

    1997-05-01

    Joints which exhibit tough fracture behavior were formed in a composite with a Si/SiC matrix reinforced with Textron SCS-6 fibers with either boron nitride or silicon nitride fiber coatings. In composites with BN coatings fibers were aligned uniaxially, while composites with Si 3 N 4 -coated fibers had a 0/90 degree architecture. Lapped joints (joints with overlapping fingers) were necessary to obtain tough behavior. Geometrical requirements necessary to avoid brittle joint failure have been proposed. Joints with a simple overlap geometry (only a few fingers) would have to be very long in order to prevent brittle failure. Typical failure in these joints is caused by a crack propagating along the interfaces between the joint fingers. Joints of the same overall length, but with geometry changed to be symmetric about the joint centerline and with an extra shear surface exhibited tough fractures accompanied with extensive fiber pullout. The initial matrix cracking of these joints was relatively low because cracks propagated easily through the ends of the fingers. Joints with an optimized stepped sawtooth geometry produced composite-like failures with the stress/strain curves containing an elastic region followed by a region of rising stress with an increase of strain. Increasing the fiber/matrix interfacial strength from 9 to 25 MPa, by changing the fiber coating, increased matrix cracking and ultimate strength of the composite significantly. The best joints had matrix cracking stress and ultimate strength of 138 and 240 MPa, respectively. Joint failure was preceded by multiple matrix cracking in the entire composite. The high strength of the joints will permit building of structures containing joints with only a minor reduction of design stresses

  12. Foamable compositions and formations treatment

    Energy Technology Data Exchange (ETDEWEB)

    Clampitt, R.L.

    1981-11-17

    Thermally stable foamable gelled compositions are disclosed suitable for postprimary oil recovery e.g., steam- or gas-foamed systems comprising water, a surfactant, a polymeric viscosifier, an aldehyde component, and at least one phenolic component such as resorcinol, catechol, and the like, as well as selected oxidized phenolic materials such as 1,4-benzoquinone of natural or synthetic origin and natural and modified tannins. The gel compositions can additionally contain gel stabilizers such as sulfomethylated quebracho (Smq) and chemical buffering agents such as sodium bicarbonate.

  13. Computer Music Synthesis and Composition

    Science.gov (United States)

    Ayers, Lydia

    What is computer music composition? Composers are using the computer for everything from MIDI instruments communicating with computer sequencers, pitch trackers analyzing the sounds of acoustic instruments and converting them to pitch information, live performers with recorded music, performers with interactive computer programs, computer music produced by dancers using sensors, automatic music composition with the computer programs composing the music, composing with sounds or parts of sounds rather than notes, how to structure the use of time, composing with timbres, or the colors of sounds, and timbre morphing, such as a gong morphing to a voice, composing with textures and texture morphing, such as fluttertonguing morphing to pitch, granular synthesis, trills and convolution.

  14. Layout and composition for animation

    CERN Document Server

    Ghertner, Ed

    2012-01-01

    This essential, hands-on guide is filled with examples of what a composition should look like and example of poorly designed layouts. Spot potential problems before they cost time and money, and adapt creative solutions for your own projects with this invaluable resource for beginner and intermediate artists.  With Beauty and the Beast examples and Simpson character layouts, readers will learn how to develop character layout and background layout as well as strengthen composition  styles with a creative toolset of trick shot examples and inspirational case studies. A companion website will

  15. Molecular characterization of composite interfaces

    International Nuclear Information System (INIS)

    Ishida, H.

    1982-01-01

    The Fourier Transform Infrared Spectroscopy was applied to elucidate the molecular structures of the glass/matrix interface. The various interfaces and interphases were studied. It is found that the structure of the silane in a treating solution is important in determining the structure of the silane on glass fibers, influences the macroscopic properties of composites. The amount of silane on glass fibers, the state of hydrogen bonding, orientation, copolymerization of the organicfunctionality with the matrix, curing of the silane, and effect of water on the interface were investigated. It is shown that the molecular approach is useful to interpret and predict physicomechanical properties of composites

  16. Radiation-curable organopolysiloxane composition

    International Nuclear Information System (INIS)

    Gordon, D.J.; Ziemelis, M.J.

    1979-01-01

    A radiation-curable polydiorganosiloxane composition comprises (A) a triorganosiloxane-endblocked polydiorganosiloxane with a major proportion of methyl radicals and a minor proportion of mercaptoalkyl radicals, (B) optionally a polymethylvinylsiloxane and (C), 1,1'-oxy-bis(1-methyl-1-silacyclopentene). From 0.2 to 2.0 silicon-bonded aliphatically unsaturated radicals are present for every silicon-bonded mercaptoalkyl radical. The molar ratio of silicon-bonded vinyl radicals to 1-methyl-1-silacyclopentenyl radicals is from 0 to 1.0. The composition is useful for coating onto a solid substrate and, after curing, improves the release of adhesive materials from the substrate. (author)

  17. Structural biological composites: An overview

    Science.gov (United States)

    Meyers, Marc A.; Lin, Albert Y. M.; Seki, Yasuaki; Chen, Po-Yu; Kad, Bimal K.; Bodde, Sara

    2006-07-01

    Biological materials are complex composites that are hierarchically structured and multifunctional. Their mechanical properties are often outstanding, considering the weak constituents from which they are assembled. They are for the most part composed of brittle (often, mineral) and ductile (organic) components. These complex structures, which have risen from millions of years of evolution, are inspiring materials scientists in the design of novel materials. This paper discusses the overall design principles in biological structural composites and illustrates them for five examples; sea spicules, the abalone shell, the conch shell, the toucan and hornbill beaks, and the sheep crab exoskeleton.

  18. Foundations of compositional model theory

    Czech Academy of Sciences Publication Activity Database

    Jiroušek, Radim

    2011-01-01

    Roč. 40, č. 6 (2011), s. 623-678 ISSN 0308-1079 R&D Projects: GA MŠk 1M0572; GA ČR GA201/09/1891; GA ČR GEICC/08/E010 Institutional research plan: CEZ:AV0Z10750506 Keywords : multidimensional probability distribution * conditional independence * graphical Markov model * composition of distributions Subject RIV: IN - Informatics, Computer Science Impact factor: 0.667, year: 2011 http://library.utia.cas.cz/separaty/2011/MTR/jirousek-foundations of compositional model theory.pdf

  19. Spectral ellipsometry of nanodiamond composite

    International Nuclear Information System (INIS)

    Yastrebov, S.G.; Ivanov-Omskij, V.I.; Gordeev, S.K.; Garriga, M.; Alonso, I.A.

    2006-01-01

    Methods of spectral ellipsometry were applied for analysis of optical properties of nanodiamond based composite in spectral region 1.4-5 eV. The nanocomposite was synthesized by molding of ultradispersed nanodiamond powder in the course of heterogeneous chemical reaction of decomposition of methane, forming pyrocarbon interconnecting nanodiamond grains. The energy of σ + π plasmon of pyrocarbon component of nanodiamond composite was restored which proves to be ∼ 24 eV; using this value, an estimation was done of pyrocarbon matrix density, which occurs to be 2 g/cm 3 [ru

  20. M-quasi-hyponormal composition operators

    Directory of Open Access Journals (Sweden)

    Pushpa R. Suri

    1987-01-01

    Full Text Available A necessary and sufficient condition is obtained for M-quasi-hyponormal composition operators. It has also been proved that the class of M-quasi-hyponormal composition operators coincides with the class of M-paranormal composition operators. Existence of M-hyponormal composition operators which are not hyponormal; and M-quasihyponormal composition operators which are not M-hyponormal and quasi-hyponormal are also shown.

  1. Standardization of Tests for Advanced Composites

    OpenAIRE

    石川, 隆司; ISHIKAWA, Takashi; 野口, 義男; NOGUCHI, Yoshio; 濱口, 泰正; HAMAGUCHI, Yasumasa

    2003-01-01

    Advanced composites are essentially the only feasible materials for the construction of newly developed aerospace vehicle. However, the path to be followed for the validation, evaluation and certification of composite aircraft structures is quite different from that of traditional metallic aircraft structures, and the importance of a composites database is now well recognized. A key issue in constructing a fully descriptive composites database is to establish standard composite test methods, ...

  2. Extending Profiles with Stereotypes for Composite Concepts

    OpenAIRE

    Quartel, Dick; Dijkman, R.M.; van Sinderen, Marten J.; Briand, L.; Williams, C.

    2005-01-01

    This paper proposes an extension of the UML 2.0 profiling mechanism. This extension facilitates a language designer to introduce composite concepts as separate conceptual and notational elements in a modelling language. Composite concepts are compositions of existing concepts. To facilitate the introduction of composite concepts, the notion of stereotype is extended. This extension defines how a composite concept can be specified and added to a language’s metamodel, ithout modifying the exist...

  3. Student assessment by objective structured examination in a neurology clerkship

    Science.gov (United States)

    Adesoye, Taiwo; Smith, Sandy; Blood, Angela; Brorson, James R.

    2012-01-01

    Objectives: We evaluated the reliability and predictive ability of an objective structured clinical examination (OSCE) in the assessment of medical students at the completion of a neurology clerkship. Methods: We analyzed data from 195 third-year medical students who took the OSCE. For each student, the OSCE consisted of 2 standardized patient encounters. The scores obtained from each encounter were compared. Faculty clinical evaluations of each student for 2 clinical inpatient rotations were also compared. Hierarchical regression analysis was applied to test the ability of the averaged OSCE scores to predict standardized written examination scores and composite clinical scores. Results: Students' OSCE scores from the 2 standardized patient encounters were significantly correlated with each other (r = 0.347, p neurology clerkship. PMID:22855865

  4. Interaction design in service compositions

    NARCIS (Netherlands)

    Dirgahayu, T.

    2010-01-01

    This thesis proposes a concept and transformations for designing interactions in a service composition at related abstraction levels. The concept and transformations are aimed at helping designers to bridge the conceptual gap between the business and software domains. In this way, the complexity of

  5. Cylindrical Piezoelectric Fiber Composite Actuators

    Science.gov (United States)

    Allison, Sidney G.; Shams, Qamar A.; Fox, Robert L.

    2008-01-01

    The use of piezoelectric devices has become widespread since Pierre and Jacques Curie discovered the piezoelectric effect in 1880. Examples of current applications of piezoelectric devices include ultrasonic transducers, micro-positioning devices, buzzers, strain sensors, and clocks. The invention of such lightweight, relatively inexpensive piezoceramic-fiber-composite actuators as macro fiber composite (MFC) actuators has made it possible to obtain strains and displacements greater than those that could be generated by prior actuators based on monolithic piezoceramic sheet materials. MFC actuators are flat, flexible actuators designed for bonding to structures to apply or detect strains. Bonding multiple layers of MFC actuators together could increase force capability, but not strain or displacement capability. Cylindrical piezoelectric fiber composite (CPFC) actuators have been invented as alternatives to MFC actuators for applications in which greater forces and/or strains or displacements may be required. In essence, a CPFC actuator is an MFC or other piezoceramic fiber composite actuator fabricated in a cylindrical instead of its conventional flat shape. Cylindrical is used here in the general sense, encompassing shapes that can have circular, elliptical, rectangular or other cross-sectional shapes in the planes perpendicular to their longitudinal axes.

  6. European standards for composite construction

    NARCIS (Netherlands)

    Stark, J.W.B.

    2000-01-01

    The European Standards Organisation (CEN) has planned to develop a complete set of harmonized European building standards. This set includes standards for composite steel and concrete buildings and bridges. The Eurocodes, being the design standards, form part of this total system of European

  7. Hydrodynamic Forces on Composite Structures

    Science.gov (United States)

    2014-06-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited HYDRODYNAMIC ...Thesis 4. TITLE AND SUBTITLE HYDRODYNAMIC FORCES ON COMPOSITE STRUCTURES 5. FUNDING NUMBERS 6. AUTHOR(S) Scott C. Millhouse 7. PERFORMING...angles yields different free surface effects including vortices and the onset of cavitation . 14. SUBJECT TERMS Fluid structure interaction, FSI, finite

  8. Fundamental Composite (Goldstone) Higgs Dynamics

    DEFF Research Database (Denmark)

    Cacciapaglia, G.; Sannino, Francesco

    2014-01-01

    We provide a unified description, both at the effective and fundamental Lagrangian level, of models of composite Higgs dynamics where the Higgs itself can emerge, depending on the way the electroweak symmetry is embedded, either as a pseudo-Goldstone boson or as a massive excitation of the conden...... searches of new physics at the Large Hadron Collider....

  9. Phospholipid composition of Dipylidium caninum.

    Science.gov (United States)

    Chopra, A K; Jain, S K; Vinayak, V K; Khuller, G K

    1978-11-15

    The phospholipid composition of Dipylidium caninum has been studied. Chloroform-methanol-soluble fraction amounted to 2.4% and phospholipids to 0.5% of the wet weight of the parasite. Phosphatidyl choline and phosphatidyl ethanolamine represented the bulk of the phospholipids, whereas phosphatidyl serine, phosphatidyl inositol, lysolecithin and lysophosphatidyl ethanolamine were present in minor amounts. Sulfatides were also identified in this parasite.

  10. Hyperhalogens and highly electronegative compositions

    Energy Technology Data Exchange (ETDEWEB)

    Jena, Puru; Gantefoer, Gerd

    2016-08-16

    Hyperhalogens, a new class of highly electronegative species, are now invented. A hyperhalogen is a superhalogen-containing composition in which the electron affinity (EA) of the hyperhalogen is even larger than that of the superhalogens they are composed of. Novel production methods are provided in which highly electronegative species are produced by surrounding a central metal atom by superhalogen moieties.

  11. Composite blade damaging under impact

    NARCIS (Netherlands)

    Menouillard, T.; Réthoré, J.; Bung, H.; Suffis, A.

    2006-01-01

    Composites materials are now being used in primary aircraft structures, and other domains because of numerous advantages. A part of a continuous in-flight operating costs, gas turbine engine manufacturers are always looking for ways to decrease engine weight. This is the case of compressor blades

  12. Compositional and Quantitative Model Checking

    DEFF Research Database (Denmark)

    Larsen, Kim Guldstrand

    2010-01-01

    This paper gives a survey of a composition model checking methodology and its succesfull instantiation to the model checking of networks of finite-state, timed, hybrid and probabilistic systems with respect; to suitable quantitative versions of the modal mu-calculus [Koz82]. The method is based...

  13. Body composition: Where and when.

    Science.gov (United States)

    Mazzoccoli, Gianluigi

    2016-08-01

    The in vivo evaluation of body composition is essential in many clinical investigations, in order to accurately describe and monitor the nutritional status of a range of medical conditions and physiological processes, including sick and malnourished patients, pregnant women, breastfeeding women and the elderly, as well as in patients with cancer, osteoporosis and many other diseases. This research area is also important to the field of human nutrition and exercise physiology. Several research investigations have indicated the importance of measuring fat deposition in different body compartments, in order to gain a fuller understanding of the genetic factors that contribute to obesity, obesity-related disorders, such as dyslipidemia, and thereby to a fuller understanding of obesity associated cardio-metabolic disorders, with relevance to the relationship between body composition and energy expenditure. The spatial and temporal dimension, where and when, may influence the physiological relevance and the pathological implications of the fat composition of different body compartments, and, as such, is a new element to be considered when assessing body composition. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Composite Materials: An Educational Need.

    Science.gov (United States)

    Saliba, Tony E.; Snide, James A.

    1990-01-01

    Described is the need to incorporate the concepts and applications of advanced composite materials into existing chemical engineering programs. Discussed are the justification for, and implementation of topics including transport phenomena, kinetics and reactor design, unit operations, and product and process design. (CW)

  15. Models for Textile Composites Forming

    NARCIS (Netherlands)

    Akkerman, Remko; ten Thije, R.H.W.

    2009-01-01

    Drape of dry fabrics or prepregs was recognised as an important feature in composites forming operations from the start. In the 1950s the first mathematical models were developed based on purely kinematic arguments. The assumption of zero fibre strains and trellis deformations led to the socalled

  16. Carbon nanotube-chalcogenide composite

    Czech Academy of Sciences Publication Activity Database

    Stehlík, Š.; Orava, J.; Kohoutek, T.; Wágner, T.; Frumar, M.; Zima, Vítězslav; Hara, T.; Matsui, Y.; Ueda, K.; Pumera, M.

    2010-01-01

    Roč. 183, č. 1 (2010), s. 144-149 ISSN 0022-4596 R&D Projects: GA ČR GA203/08/0208 Institutional research plan: CEZ:AV0Z40500505 Keywords : carbon nanotubes * chalcogenide glasses * composites Subject RIV: CA - Inorganic Chemistry Impact factor: 2.261, year: 2010

  17. Review of natural fiber composites

    Science.gov (United States)

    Rohan, T.; Tushar, B.; T, Mahesha G.

    2018-02-01

    Development of new alternative materials to the existing traditional metals, alloys and synthetic materials is the new buzz in recent research activities at the academic and industrial level taking place all over the world. Earning carbon credits by minimizing the atmospheric pollution is getting an increase in attention by industries. One small step to conserve the atmosphere around us is to use natural resources in making fully bio degradable or partially bio degradable composite materials. Such prepared alternative materials can find applications in interior housing, automotive, marine, domestic, and other applications. Composites made by using appropriate natural fibers as reinforcements is a possibility that ensures such a reality as they can be well received in multiple disciplines of engineering. Results published from various research activities illustrates that natural fiber composites can successfully be adapted for non-structural, moderate load bearing indoor applications. Further, the few deficiencies in the natural fibers can be overcome by subjecting them to morphological changes by various physical or chemical treatment methods. The overall objective of this paper is to provide a comprehensive overview of the property profiles of Natural Fiber Composites.

  18. Modifying milk composition through forage

    NARCIS (Netherlands)

    Elgersma, A.; Tamminga, S.; Ellen, G.

    2006-01-01

    The fatty acid (FA) composition of cows milk has become less favorable to human health in the last four decades due to changed feeding and management practices, notably higher proportions of concentrates and silages in diets with less grazing. Essential FA and conjugated linoleic acid (CLA)

  19. Unblockable Compositions of Software Components

    DEFF Research Database (Denmark)

    Dong, Ruzhen; Faber, Johannes; Liu, Zhiming

    2012-01-01

    We present a new automata-based interface model describing the interaction behavior of software components. Contrary to earlier component- or interface-based approaches, the interface model we propose specifies all the non-blockable interaction behaviors of a component with any environment...... composition of interface models preserves unblockable sequences of provided services....

  20. Dynamic Analysis of Composite Rotors

    Directory of Open Access Journals (Sweden)

    S. P. Singh

    1996-01-01

    accounted for. Material damping is also taken into account. The layerwise theory is compared with conventionally used equivalent modulus beam theory. Some interesting case studies are presented. The effect of various parameters on dynamic behavior and stability of a composite rotor is presented.

  1. Pultrusion processes for composite manufacture

    NARCIS (Netherlands)

    Baran, Ismet; Boisse, Philippe

    2015-01-01

    In this chapter, numerical modeling strategies are presented for the pultrusion of thermosetting composite profiles. The focus is particularly on the forming die and postdie region in which the multiphysics takes place. The state-of-the-art thermochemical–thermomechanical models are exposed in which

  2. Nanostructured lanthanum manganate composite cathode

    DEFF Research Database (Denmark)

    Wang, Wei Guo; Liu, Yi-Lin; Barfod, Rasmus

    2005-01-01

    that the (La1-xSrx)(y)MnO3 +/-delta (LSM) composite cathodes consist of a network of homogenously distributed LSM, yttria-stabilized zirconia (YSZ), and pores. The individual grain size of LSM or YSZ is approximately 100 nm. The degree of contact between cathode and electrolyte is 39% on average. (c) 2005...

  3. Polyvinyl alcohol–cellulose composite

    Indian Academy of Sciences (India)

    We have made an attempt to prepare taste sensor material by using functionalized polymer without any lipid. PVA–cellulose composite has been modified to use as the sensor material. The research work covers polymer membrane preparation, morphology study and structural characterization of the membrane and study of ...

  4. Ceramic composites: Enabling aerospace materials

    Science.gov (United States)

    Levine, S. R.

    1992-01-01

    Ceramics and ceramic matrix composites (CMC) have the potential for significant impact on the performance of aerospace propulsion and power systems. In this paper, the potential benefits are discussed in broad qualitative terms and are illustrated by some specific application case studies. The key issues in need of resolution for the potential of ceramics to be realized are discussed.

  5. Mechanical Properties of Composite Materials

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Okayasu

    2014-10-01

    Full Text Available An examination has been made of the mechanical and failure properties of several composite materials, such as a short and a long carbon fiber reinforced plastic (short- and long-CFRP and metal based composite material. The short CFRP materials were used for a recycled CFRP which fabricated by the following process: the CFRP, consisting of epoxy resin with carbon fiber, is injected to a rectangular plate cavity after mixing with acrylonitrile butadiene styrene resin with different weight fractions of CFRP. The fatigue and ultimate tensile strength (UTS increased with increasing CFRP content. These correlations, however, break down, especially for tensile strength, as the CFPR content becomes more than 70%. Influence of sample temperature on the bending strength of the long-CFRP was investigated, and it appears that the strength slightly degreases with increasing the temperature, due to the weakness in the matrix. Broken fiber and pull-out or debonding between the fiber and matrix were related to the main failure of the short- and long-CFRP samples. Mechanical properties of metal based composite materials have been also investigated, where fiber-like high hardness CuAl2 structure is formed in aluminum matrix. Excellent mechanical properties were obtained in this alloy, e.g., the higher strength and the higher ductility, compared tothe same alloy without the fiber-like structure. There are strong anisotropic effects on the mechanical properties due to the fiber-like metal composite in a soft Al based matrix.

  6. Finding Atmospheric Composition (AC) Metadata

    Science.gov (United States)

    Strub, Richard F..; Falke, Stefan; Fiakowski, Ed; Kempler, Steve; Lynnes, Chris; Goussev, Oleg

    2015-01-01

    The Atmospheric Composition Portal (ACP) is an aggregator and curator of information related to remotely sensed atmospheric composition data and analysis. It uses existing tools and technologies and, where needed, enhances those capabilities to provide interoperable access, tools, and contextual guidance for scientists and value-adding organizations using remotely sensed atmospheric composition data. The initial focus is on Essential Climate Variables identified by the Global Climate Observing System CH4, CO, CO2, NO2, O3, SO2 and aerosols. This poster addresses our efforts in building the ACP Data Table, an interface to help discover and understand remotely sensed data that are related to atmospheric composition science and applications. We harvested GCMD, CWIC, GEOSS metadata catalogs using machine to machine technologies - OpenSearch, Web Services. We also manually investigated the plethora of CEOS data providers portals and other catalogs where that data might be aggregated. This poster is our experience of the excellence, variety, and challenges we encountered.Conclusions:1.The significant benefits that the major catalogs provide are their machine to machine tools like OpenSearch and Web Services rather than any GUI usability improvements due to the large amount of data in their catalog.2.There is a trend at the large catalogs towards simulating small data provider portals through advanced services. 3.Populating metadata catalogs using ISO19115 is too complex for users to do in a consistent way, difficult to parse visually or with XML libraries, and too complex for Java XML binders like CASTOR.4.The ability to search for Ids first and then for data (GCMD and ECHO) is better for machine to machine operations rather than the timeouts experienced when returning the entire metadata entry at once. 5.Metadata harvest and export activities between the major catalogs has led to a significant amount of duplication. (This is currently being addressed) 6.Most (if not all

  7. Muscle fibre type composition and body composition in hammer throwers.

    Science.gov (United States)

    Terzis, Gerasimos; Spengos, Konstantinos; Kavouras, Stavros; Manta, Panagiota; Georgiadis, Giorgos

    2010-01-01

    Aim of the present study was to describe the muscle fibre type composition and body composition of well-trained hammer throwers. Six experienced hammer throwers underwent the following measurements: one repetition maximum in squat, snatch, and clean, standing broad jump, backward overhead shot throw and the hammer throw. Dual x-ray absorptiometry was used for body composition analysis. Fibre type composition and cross sectional area was determined in muscle biopsy samples of the right vastus lateralis. Eight physical education students served as a control group. One repetition maximum in squat, snatch and clean for the hammer throwers was 245 ± 21, 132 ± 13 and 165 ± 12kg, respectively. Lean body mass was higher in hammer throwers (85.9 ± 3. 9kg vs. 62.7 ± 5.1kg (p hammer throwers and 51 ± 8% in the control group (p Hammer throwers had significantly larger type IIA fibres (7703 ± 1171 vs. 5676 ± 1270μm(2), p Hammer throwing performance correlated significantly with lean body mass (r = 0.81, p hammer throwers have larger lean body mass and larger muscular areas occupied by type II fibres, compared with relatively untrained subjects. Moreover, it seems that the enlarged muscle mass of the hammer throwers contributes significantly to the hammer throwing performance. Key pointsWell-trained hammer throwers had increased lean body mass, higher type IIA muscle fibres cross sectional areas, as well as higher bone mineral density, compared to controls.Increased lean body mass was closely related with hammer throwing performance.The relative high percentage of type IIX muscle fibres in vastus lateralis in hammer throwers warrants further investigation.

  8. Perspectives on the relation between composition, compositionality and exocentricity

    OpenAIRE

    Scholz, Cosima

    2014-01-01

    This PhD Project deals with Romance Verb-Noun-Compounds (VNC), a productive exocentric word formation process in several Romance languages. Due to its special structural and semantic configuration, it gives rise to many questions that partly coincide with recent issues discussed in linguistic theory. The aim of this work is twofold: First, Romance VNC are embedded in recent developments concerning aspects of morphological theory, compositionality and thoughts about the decoding of structurall...

  9. arXiv Minimal Fundamental Partial Compositeness

    CERN Document Server

    Cacciapaglia, Giacomo; Sannino, Francesco; Thomsen, Anders Eller

    Building upon the fundamental partial compositeness framework we provide consistent and complete composite extensions of the standard model. These are used to determine the effective operators emerging at the electroweak scale in terms of the standard model fields upon consistently integrating out the heavy composite dynamics. We exhibit the first effective field theories matching these complete composite theories of flavour and analyse their physical consequences for the third generation quarks. Relations with other approaches, ranging from effective analyses for partial compositeness to extra dimensions as well as purely fermionic extensions, are briefly discussed. Our methodology is applicable to any composite theory of dynamical electroweak symmetry breaking featuring a complete theory of flavour.

  10. Composite anode for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    de Guzman, Rhet C.; Ng, K.Y. Simon; Salley, Steven O.

    2018-03-06

    A composite anode for a lithium-ion battery is manufactured from silicon nanoparticles having diameters mostly under 10 nm; providing an oxide layer on the silicon nanoparticles; dispersing the silicon nanoparticles in a polar liquid; providing a graphene oxide suspension; mixing the polar liquid containing the dispersed silicone nanoparticles with the graphene oxide suspension to obtain a composite mixture; probe-sonicating the mixture for a predetermined time; filtering the composite mixture to obtain a solid composite; drying the composite; and reducing the composite to obtain graphene and silicon.

  11. Chemical compositions, methods of making the chemical compositions, and structures made from the chemical compositions

    Science.gov (United States)

    Yang, Lei; Cheng, Zhe; Liu, Ze; Liu, Meilin

    2015-01-13

    Embodiments of the present disclosure include chemical compositions, structures, anodes, cathodes, electrolytes for solid oxide fuel cells, solid oxide fuel cells, fuel cells, fuel cell membranes, separation membranes, catalytic membranes, sensors, coatings for electrolytes, electrodes, membranes, and catalysts, and the like, are disclosed.

  12. Boron carbide-carbon composites and composites for cryogenic applications

    International Nuclear Information System (INIS)

    Sheinberg, H.

    1979-01-01

    Because of its neutronic properties, high hardness, and high melting temperature, boron carbide (B 4 C) is widely used at the Los Alamos Scientific Laboratory. However because of its hardness and mode of manufacture, it is expensive to machine finish to tight dimensional specifictions. For some neutronic applications, a density considerably below the theoretical 2.52 Mg/m 3 was acceptable, and this relaxation in density specification permitted addition of carbon as a second phase to reduce machining costs. We conducted an experimental program to prepare 50.8-mm-diam by 34.8-mm-thick cylinders of B 4 C and B 4 C-C composites with concentrations of carbon varying from 5.5 to 30 volume percent. Additionally we used three forms of carbon, natural flake graphite, synthetic graphite flour, and a fine furnace black as the source of the second phase. We determined the sound velocity, compressive strength, coefficient of thermal expansion, electrical resistivity, and microstructure as functions of composition. Additionally, an enriched boron ( 10 B)-carbon composite was studied as an alternate material

  13. Constraints on Europa's Ocean Composition Imposed by Its Surface Composition

    Science.gov (United States)

    Johnson, P. V.; Hodyss, R. P.; Vu, T. H.; Choukroun, M.

    2017-12-01

    Of the non-terrestrial environments within our Solar System, Europa's global liquid water ocean is arguably the most likely to be habitable. As such, understanding the habitability of Europa's ocean is of great interest to astrobiology and is the focus of missions currently being considered for further exploration of Europa. However, direct analysis of the ocean is unlikely in the foreseeable future. As such, our best means of constraining the subsurface ocean composition and its subsequent habitability currently is by further study of Europa's surface chemical composition. Recently, there has been a body of work published that looks at the chemistry of frozen brines representing putative ocean compositions. Here we take a simplified model of a four ionic component (Na, Mg, SO4, Cl) solution and map out what minerals are formed upon freezing as a function of relative ionic concentration, pH, etc. A `flow-chart' of the freezing sequence was developed based on both published and recently acquired experimental results. In performing this exercise, we are able to begin making meaningful links between observations of the surface chemistry and the chemical environment of the internal ocean.

  14. Use of Excel ion exchange equilibrium solver with WinGEMS to model and predict NPE distribution in the Mead/Westvaco Evandale, TX, hardwood bleach plant

    Science.gov (United States)

    Christopher Litvay; Alan Rudie; Peter Hart

    2003-01-01

    An Excel spreadsheet developed to solve the ion-exchange equilibrium in wood pulps has been linked by dynamic data exchange to WinGEMS and used to model the non-process elements in the hardwood bleach plant of the Mead/Westvaco Evandale mill. Pulp and filtrate samples were collected from the diffusion washers and final wash press of the bleach plant. A WinGEMS model of...

  15. Stiffened Composite Fuselage Barrel Optimization

    Science.gov (United States)

    Movva, R. G.; Mittal, A.; Agrawal, K.; Upadhyay, C. S.

    2012-07-01

    In a typical commercial transport aircraft, Stiffened skin panels and frames contribute around 40% of the fuselage weight. In the current study a stiffened composite fuselage skin panel optimization engine is developed for optimization of the layups of composite panels and stringers using Genetic Algorithm (GA). The skin and stringers of the fuselage section are optimized for the strength and the stability requirements. The selection of the GA parameters considered for the optimization is arrived by performing case studies on selected problems. The optimization engine facilitates in carrying out trade studies for selection of the optimum ply layup and material combination for the configuration being analyzed. The optimization process is applied on a sample model and the results are presented.

  16. Composite pipe to metal joint

    Energy Technology Data Exchange (ETDEWEB)

    Leslie, James C.; Leslie, II, James C.; Heard, James; Truong, Liem V.; Josephson, Marvin

    2017-06-27

    A method for making a metal to composite tube joint including selecting an elongated interior fitting constructed with an exterior barrel, reduced in exterior diameter to form a distally facing annular shoulder and then projecting still further distally to form an interior sleeve having a radially outwardly facing bonding surface. Selecting an elongated metal outer sleeve formed proximally with a collar constructed for receipt over the barrel and increased in interior diameter and projecting distally to form an exterior sleeve having a radially inwardly facing bonding surface cooperating with the first bonding surface to form an annulus receiving an extremity of a composite tube and a bond bonding the extremity of the tube to the bonding surfaces.

  17. Friction Material Composites Materials Perspective

    CERN Document Server

    Sundarkrishnaa, K L

    2012-01-01

    Friction Material Composites is the first of the five volumes which strongly educates and updates engineers and other professionals in braking industries, research and test labs. It explains besides the formulation of design processes and its complete manufacturing input. This book gives an idea of mechanisms of friction and how to control them by designing .The book is  useful for designers  of automotive, rail and aero industries for designing the brake systems effectively with the integration of friction material composite design which is critical. It clearly  emphasizes the driving  safety and how serious designers should  select the design input. The significance of friction material component like brake pad or a liner as an integral part of the brake system of vehicles is explained. AFM pictures at nanolevel illustrate broadly the explanations given.

  18. Composite Electrodes for Electrochemical Supercapacitors

    Directory of Open Access Journals (Sweden)

    Yang QuanMin

    2010-01-01

    Full Text Available Abstract Manganese dioxide nanofibers with length ranged from 0.1 to 1 μm and a diameter of about 4–6 nm were prepared by a chemical precipitation method. Composite electrodes for electrochemical supercapacitors were fabricated by impregnation of the manganese dioxide nanofibers and multiwalled carbon nanotubes (MWCNT into porous Ni plaque current collectors. Obtained composite electrodes, containing 85% of manganese dioxide and 15 mass% of MWCNT, as a conductive additive, with total mass loading of 7–15 mg cm−2, showed a capacitive behavior in 0.5-M Na2SO4 solutions. The decrease in stirring time during precipitation of the nanofibers resulted in reduced agglomeration and higher specific capacitance (SC. The highest SC of 185 F g−1 was obtained at a scan rate of 2 mV s−1 for mass loading of 7 mg cm−2. The SC decreased with increasing scan rate and increasing electrode mass.

  19. Composite Electrodes for Electrochemical Supercapacitors

    Science.gov (United States)

    Li, Jun; Yang, Quan Min; Zhitomirsky, Igor

    2010-03-01

    Manganese dioxide nanofibers with length ranged from 0.1 to 1 μm and a diameter of about 4-6 nm were prepared by a chemical precipitation method. Composite electrodes for electrochemical supercapacitors were fabricated by impregnation of the manganese dioxide nanofibers and multiwalled carbon nanotubes (MWCNT) into porous Ni plaque current collectors. Obtained composite electrodes, containing 85% of manganese dioxide and 15 mass% of MWCNT, as a conductive additive, with total mass loading of 7-15 mg cm-2, showed a capacitive behavior in 0.5-M Na2SO4 solutions. The decrease in stirring time during precipitation of the nanofibers resulted in reduced agglomeration and higher specific capacitance (SC). The highest SC of 185 F g-1 was obtained at a scan rate of 2 mV s-1 for mass loading of 7 mg cm-2. The SC decreased with increasing scan rate and increasing electrode mass.

  20. Creep of fibrous composite materials

    DEFF Research Database (Denmark)

    Lilholt, Hans

    1985-01-01

    Models are presented for the creep behaviour of fibrous composite materials with aligned fibres. The models comprise both cases where the fibres remain rigid in a creeping matrix and cases where the fibres are creeping in a creeping matrix. The treatment allows for several contributions...... to the creep strength of composites. The advantage of combined analyses of several data sets is emphasized and illustrated for some experimental data. The analyses show that it is possible to derive creep equations for the (in situ) properties of the fibres. The experiments treated include model systems...... such as Ni + W-fibres, high temperature materials such as Ni + Ni3Al + Cr3C2-fibres, and medium temperature materials such as Al + SiC-fibres. For the first two systems reasonable consistency is found for the models and the experiments, while for the third system too many unquantified parameters exist...

  1. Interpreting the cosmic ray composition

    International Nuclear Information System (INIS)

    O'C Drury, L.; Ellisson, D.C; Meyer, J.-P.

    2000-01-01

    The detailed pattern of elemental abundances in the Galactic Cosmic Rays is well determined at energies of a few GeV per nucleon. After correction for propagation effects the inferred source composition shows significant deviations from the standard pattern of Galactic elemental abundances. These deviations, surprisingly overabundances of the heavy elements relative to Hydrogen, are clearly a significant clue to the origin of the cosmic rays, but one which has proven very difficult to interpret. We have recently shown that the 'standard' model for the origin of the bulk of the Galactic cosmic rays, namely acceleration by the diffusive shock acceleration process at the strong shocks associated with supernova remnants, can quantitatively explain all features of the source composition if the acceleration occurs from a dusty interstellar medium. This success must be regarded as one of the stronger pieces of evidence in favour of the standard model

  2. Interpreting the cosmic ray composition

    Energy Technology Data Exchange (ETDEWEB)

    O' C Drury, L.; Ellisson, D.C; Meyer, J.-P

    2000-01-31

    The detailed pattern of elemental abundances in the Galactic Cosmic Rays is well determined at energies of a few GeV per nucleon. After correction for propagation effects the inferred source composition shows significant deviations from the standard pattern of Galactic elemental abundances. These deviations, surprisingly overabundances of the heavy elements relative to Hydrogen, are clearly a significant clue to the origin of the cosmic rays, but one which has proven very difficult to interpret. We have recently shown that the 'standard' model for the origin of the bulk of the Galactic cosmic rays, namely acceleration by the diffusive shock acceleration process at the strong shocks associated with supernova remnants, can quantitatively explain all features of the source composition if the acceleration occurs from a dusty interstellar medium. This success must be regarded as one of the stronger pieces of evidence in favour of the standard model.

  3. Origin and composition of Mercury

    International Nuclear Information System (INIS)

    Lewis, J.S.

    1988-01-01

    The predictions of the expected range of composition of Mercury at the time of its formation made on the basis of a suite of condensation-accretion models of Mercury spanning a range of condensation temperature and accretion sampling functions appropriate to Mercury are examined. It is concluded that these compositonal models can, if modified to take into account the nonselective loss of most of the silicate component of the planet during accretion, provide compositional predictions for the Weidenschilling (1978, 1980) mechanism for the accretion of a metal-rich Mercury. The silicate portion would, in this case, contain 3.6 to 4.5 percent alumina, roughly 1 percent of alkali oxides, and between 0.5 and 6 percent FeO

  4. Students’ performance in the different clinical skills assessed in OSCE: what does it reveal?

    Directory of Open Access Journals (Sweden)

    Joong Hiong Sim

    2015-02-01

    Full Text Available Introduction: The purpose of this study was to compare students’ performance in the different clinical skills (CSs assessed in the objective structured clinical examination. Methods: Data for this study were obtained from final year medical students’ exit examination (n=185. Retrospective analysis of data was conducted using SPSS. Means for the six CSs assessed across the 16 stations were computed and compared. Results: Means for history taking, physical examination, communication skills, clinical reasoning skills (CRSs, procedural skills (PSs, and professionalism were 6.25±1.29, 6.39±1.36, 6.34±0.98, 5.86±0.99, 6.59±1.08, and 6.28±1.02, respectively. Repeated measures ANOVA showed there was a significant difference in the means of the six CSs assessed [F(2.980, 548.332=20.253, p<0.001]. Pairwise multiple comparisons revealed significant differences between the means of the eight pairs of CSs assessed, at p<0.05. Conclusions: CRSs appeared to be the weakest while PSs were the strongest, among the six CSs assessed. Students’ unsatisfactory performance in CRS needs to be addressed as CRS is one of the core competencies in medical education and a critical skill to be acquired by medical students before entering the workplace. Despite its challenges, students must learn the skills of clinical reasoning, while clinical teachers should facilitate the clinical reasoning process and guide students’ clinical reasoning development.

  5. Evaluating Neonatal Resuscitation Skills of Nursing and Midwifery Students Using Objective Structured Clinical Examination (OSCE

    Directory of Open Access Journals (Sweden)

    Javad Malekzadeh

    2015-07-01

    Conclusion: The students’ skills in neonatal resuscitation were lower than expected. As competence in this area is of high significance for the improvement of neonatal outcomes, holding training workshops through applying novel training methods is recommended.

  6. Students' performance in the different clinical skills assessed in OSCE: what does it reveal?

    Science.gov (United States)

    Sim, Joong Hiong; Abdul Aziz, Yang Faridah; Mansor, Azura; Vijayananthan, Anushya; Foong, Chan Choong; Vadivelu, Jamuna

    2015-01-01

    The purpose of this study was to compare students' performance in the different clinical skills (CSs) assessed in the objective structured clinical examination. Data for this study were obtained from final year medical students' exit examination (n=185). Retrospective analysis of data was conducted using SPSS. Means for the six CSs assessed across the 16 stations were computed and compared. Means for history taking, physical examination, communication skills, clinical reasoning skills (CRSs), procedural skills (PSs), and professionalism were 6.25±1.29, 6.39±1.36, 6.34±0.98, 5.86±0.99, 6.59±1.08, and 6.28±1.02, respectively. Repeated measures ANOVA showed there was a significant difference in the means of the six CSs assessed [F(2.980, 548.332)=20.253, pskill to be acquired by medical students before entering the workplace. Despite its challenges, students must learn the skills of clinical reasoning, while clinical teachers should facilitate the clinical reasoning process and guide students' clinical reasoning development.

  7. The Influence of First Impressions on Subsequent Ratings within an OSCE Station

    Science.gov (United States)

    Wood, Timothy J.; Chan, James; Humphrey-Murto, Susan; Pugh, Debra; Touchie, Claire

    2017-01-01

    Competency-based assessment is placing increasing emphasis on the direct observation of learners. For this process to produce valid results, it is important that raters provide quality judgments that are accurate. Unfortunately, the quality of these judgments is variable and the roles of factors that influence the accuracy of those judgments are…

  8. 40 CFR 300.145 - Special teams and other assistance available to OSCs/RPMs.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS... environmental chemistry, oil slick tracking, pollutant transport modeling, natural resources at risk.... Thus, responsible parties or other persons attempting to perform such operations without adequate...

  9. i-Assess: Evaluating the impact of electronic data capture for OSCE.

    Science.gov (United States)

    Monteiro, Sandra; Sibbald, Debra; Coetzee, Karen

    2018-04-01

    Tablet-based assessments offer benefits over scannable-paper assessments; however, there is little known about the impact to the variability of assessment scores. Two studies were conducted to evaluate changes in rating technology. Rating modality (paper vs tablets) was manipulated between candidates (Study 1) and within candidates (Study 2). Average scores were analyzed using repeated measures ANOVA, Cronbach's alpha and generalizability theory. Post-hoc analyses included a Rasch analysis and McDonald's omega. Study 1 revealed a main effect of modality (F (1,152) = 25.06, p 0.8) and inter-station reliability remained constant (0.3). Rasch analyses showed no relationship between station difficulty and rating modality. Analyses of average scores may be misleading without an understanding of internal consistency and overall reliability of scores. Although updating to tablet-based forms did not result in systematic variations in scores, routine analyses ensured accurate interpretation of the variability of assessment scores. This study demonstrates the importance of ongoing program evaluation and data analysis.

  10. Ni-CeO2/C Catalysts with Enhanced OSC for the WGS Reaction

    Directory of Open Access Journals (Sweden)

    Laura Pastor-Pérez

    2015-03-01

    Full Text Available In this work, the WGS performance of a conventional Ni/CeO2 bulk catalyst is compared to that of a carbon-supported Ni-CeO2 catalyst. The carbon-supported sample resulted to be much more active than the bulk one. The higher activity of the Ni-CeO2/C catalyst is associated to its oxygen storage capacity, a parameter that strongly influences the WGS behavior. The stability of the carbon-supported catalyst under realistic operation conditions is also a subject of this paper. In summary, our study represents an approach towards a new generation of Ni-ceria based catalyst for the pure hydrogen production via WGS. The dispersion of ceria nanoparticles on an activated carbon support drives to improved catalytic skills with a considerable reduction of the amount of ceria in the catalyst formulation.

  11. Feedback in formative OSCEs: comparison between direct observation and video-based formats

    Science.gov (United States)

    Junod Perron, Noëlle; Louis-Simonet, Martine; Cerutti, Bernard; Pfarrwaller, Eva; Sommer, Johanna; Nendaz, Mathieu

    2016-01-01

    Introduction Medical students at the Faculty of Medicine, University of Geneva, Switzerland, have the opportunity to practice clinical skills with simulated patients during formative sessions in preparation for clerkships. These sessions are given in two formats: 1) direct observation of an encounter followed by verbal feedback (direct feedback) and 2) subsequent review of the videotaped encounter by both student and supervisor (video-based feedback). The aim of the study was to evaluate whether content and process of feedback differed between both formats. Methods In 2013, all second- and third-year medical students and clinical supervisors involved in formative sessions were asked to take part in the study. A sample of audiotaped feedback sessions involving supervisors who gave feedback in both formats were analyzed (content and process of the feedback) using a 21-item feedback scale. Results Forty-eight audiotaped feedback sessions involving 12 supervisors were analyzed (2 direct and 2 video-based sessions per supervisor). When adjusted for the length of feedback, there were significant differences in terms of content and process between both formats; the number of communication skills and clinical reasoning items addressed were higher in the video-based format (11.29 vs. 7.71, p=0.002 and 3.71 vs. 2.04, p=0.010, respectively). Supervisors engaged students more actively during the video-based sessions than during direct feedback sessions (self-assessment: 4.00 vs. 3.17, p=0.007; active problem-solving: 3.92 vs. 3.42, p=0.009). Students made similar observations and tended to consider that the video feedback was more useful for improving some clinical skills. Conclusion Video-based feedback facilitates discussion of clinical reasoning, communication, and professionalism issues while at the same time actively engaging students. Different time and conceptual frameworks may explain observed differences. The choice of feedback format should depend on the educational goal. PMID:27834170

  12. Feedback in formative OSCEs: comparison between direct observation and video-based formats

    Directory of Open Access Journals (Sweden)

    Noëlle Junod Perron

    2016-11-01

    Full Text Available Introduction: Medical students at the Faculty of Medicine, University of Geneva, Switzerland, have the opportunity to practice clinical skills with simulated patients during formative sessions in preparation for clerkships. These sessions are given in two formats: 1 direct observation of an encounter followed by verbal feedback (direct feedback and 2 subsequent review of the videotaped encounter by both student and supervisor (video-based feedback. The aim of the study was to evaluate whether content and process of feedback differed between both formats. Methods: In 2013, all second- and third-year medical students and clinical supervisors involved in formative sessions were asked to take part in the study. A sample of audiotaped feedback sessions involving supervisors who gave feedback in both formats were analyzed (content and process of the feedback using a 21-item feedback scale. Results: Forty-eight audiotaped feedback sessions involving 12 supervisors were analyzed (2 direct and 2 video-based sessions per supervisor. When adjusted for the length of feedback, there were significant differences in terms of content and process between both formats; the number of communication skills and clinical reasoning items addressed were higher in the video-based format (11.29 vs. 7.71, p=0.002 and 3.71 vs. 2.04, p=0.010, respectively. Supervisors engaged students more actively during the video-based sessions than during direct feedback sessions (self-assessment: 4.00 vs. 3.17, p=0.007; active problem-solving: 3.92 vs. 3.42, p=0.009. Students made similar observations and tended to consider that the video feedback was more useful for improving some clinical skills. Conclusion: Video-based feedback facilitates discussion of clinical reasoning, communication, and professionalism issues while at the same time actively engaging students. Different time and conceptual frameworks may explain observed differences. The choice of feedback format should depend on the educational goal.

  13. Chemical composition of lunar material.

    Science.gov (United States)

    Maxwell, J A; Abbey, S; Champ, W H

    1970-01-30

    Chemical and emission spectrographic analyses of three Apollo 11 samples, 10017-29, 10020-30, and 10084-132, are given. Major and minor constituents were determined both by conventional rock analysis methods and by a new composite scheme utilizing a lithium fluoborate method for dissolution of the samples and atomic absorption spectroscopy and colorimetry. Trace constituents were determined by optical emission spectroscopy involving a d-c arc, air-jet controlled.

  14. Critical energy of superconducting composites

    International Nuclear Information System (INIS)

    Jayakumar, R.

    1987-01-01

    The stability of superconducting composites is studied in one-dimensional geometry and critical quench energies are calculated by solving for the steady state temperature profile which gives the minimum energy. The present calculations give lower values for the critical energy than previous estimates. The calculations are shown to be applicable to both direct cooled and impregnated conductors. Critical energies are also calculated including the effect of temperature dependence of conductor properties. (author)

  15. Commercial transport aircraft composite structures

    Science.gov (United States)

    Mccarty, J. E.

    1983-01-01

    The role that analysis plays in the development, production, and substantiation of aircraft structures is discussed. The types, elements, and applications of failure that are used and needed; the current application of analysis methods to commercial aircraft advanced composite structures, along with a projection of future needs; and some personal thoughts on analysis development goals and the elements of an approach to analysis development are discussed.

  16. Hybrid and hierarchical composite materials

    CERN Document Server

    Kim, Chang-Soo; Sano, Tomoko

    2015-01-01

    This book addresses a broad spectrum of areas in both hybrid materials and hierarchical composites, including recent development of processing technologies, structural designs, modern computer simulation techniques, and the relationships between the processing-structure-property-performance. Each topic is introduced at length with numerous  and detailed examples and over 150 illustrations.   In addition, the authors present a method of categorizing these materials, so that representative examples of all material classes are discussed.

  17. Chemical composition of Achatina fulica

    Directory of Open Access Journals (Sweden)

    Aboua, F.

    1990-01-01

    Full Text Available Proximate composition and mineral content were determined in snail without and with shell and shell atone from Achatina fulica. This snail has high protein (above 40 %, low fat (less than 3 % and is a relatively good source of macrominerals, including calcium, phosphorus, magnesium, potassium and sodium. Achatina fulica is an excellent source of iron but is poor in copper, zinc and manganese. The snail is very rich in calcium but very poor in phosphorus, potassium and magnesium.

  18. Asymmetric Dielectric Elastomer Composite Material

    Science.gov (United States)

    Stewart, Brian K. (Inventor)

    2014-01-01

    Embodiments of the invention provide a dielectric elastomer composite material comprising a plurality of elastomer-coated electrodes arranged in an assembly. Embodiments of the invention provide improved force output over prior DEs by producing thinner spacing between electrode surfaces. This is accomplished by coating electrodes directly with uncured elastomer in liquid form and then assembling a finished component (which may be termed an actuator) from coated electrode components.

  19. Cast-in hardfacing composite

    International Nuclear Information System (INIS)

    Ji, Jia-Lin; Wang, Hua-Ming.

    1991-01-01

    Tungsten carbide and chromium ferroalloy particles in binderless state were placed on a vacuum sealed mold surface, and a wear resistant surface was formed by pouring high temperature liquid steel into the mold cavity. Higher surface hardness HRC 65-69 and increased toughness were obtained by this composite material. It is shown that a strengthened martensitic matrix alloyed by tungsten and chromium supports tungsten carbide particles as well as reformed carbides (M6C, M7C3). 3 refs

  20. Chemical composition of cigarette smoke

    Energy Technology Data Exchange (ETDEWEB)

    Guerin, M. R.

    1979-01-01

    Cigarette smoke is a concentrated aerosol of liquid particles suspended in an atmosphere consisting mainly of nitrogen, oxygen, and carbon dioxide. While the precise chemical composition of the particulate and gaseous phases is dependent on the characteristics of the cigarette and the manner in which it is smoked, both phases contain tens of hundreds of individual constitutents. Notable among potentially hazardous constituents of smoke are tar, nicotine, carbon monoxide, nitric oxide, hydrogen cyanide, acrolein, benzo(a)pyrene, and N-nitrosamines.