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Sample records for high burnout silicon

  1. Burnout among Low and High Experienced Teachers

    Directory of Open Access Journals (Sweden)

    Seyedehhava Mousavy

    2012-09-01

    Full Text Available Burnout is a serious psychological syndrome that can affect not only an individual’s well-being, but also the functioning of whole organisations, such as schools. It is characterized by emotional exhaustion, depersonalization, and decreased personal accomplishment.The level of burnout among teachers in the field of education has a negative impact on student success. The present investigation examines the level of burn out among high and low experienced teachers. It focused on a group of English teachers from different nationalities: Iranian, and Malaysian at UPM to examine if there is any relation between burnout and experience level. The sample consisted of 30 English teachers. Two instruments namely, The Maslach Burnout Inventory and Demographic Questionnaire were used to collect data. Data analysis revealed that there is no significant difference in depersonalization and personal accomplishment scores between low and high experienced teachers. But the result of this study also revealed that there is a significant difference in Emotional Exhaustion scores between low and high experienced teachers. Further research is required to explore the roots and the causes of burnout.

  2. Burnout

    OpenAIRE

    Woitsch, Marek

    2008-01-01

    This Thesis deals with the issue of the burnout syndrome and with relationship between burnout syndrome and social support. The aim of this work is based on knowledge from the literature and from experience of clinical psychiatrists to assess the significance of social support for individuals suffering from the burnout syndrome. In the Thesis, there are first defined terms burnout syndrome and social support. Consequently, there are presented the most important knowledge of social support, it...

  3. Burnout Syndrome in High School Teachers' in Bilecik, Bozuyuk

    Directory of Open Access Journals (Sweden)

    Ahmet Topuzoglu

    2009-06-01

    Full Text Available AIM: Burnout syndrome is manifested by physical exhaustion, long lasting tiredness and feelings of hopelessness. And also it consists of individual’s negative attitudes towards to life, occupation and the other persons. Burnout frequently seen in the occupations who work face to face with people like doctors, polices, nurses and managers. Generally teachers’ burnout level is higher than other occupations. Our aim is to determine the burnout levels and related factors of teachers working in high school of Bilecik Bozuyuk. METHODS: Totally 228 teachers participated to this cross sectional study (participating rate is %90.4. To find out the burnout level in these teachers Maslach Burnout Inventory was used. RESULTS: Of the total participants 52.1% were women, median age of participants were 33.0 years (Quartiles: 28.0–40.0 years There was no relation between the burnout level and the years in the occupation, weekly working time and the school that they educated. Occupational high school teachers, unwilingly occupation choosing, bad physical work environment, violence experience in the school significantly had higher points from burn out scale. CONCLUSION: Burnout level was higher in high school teachers, who didn’t want to be a teacher and who were working at bad physical environment and who had violence experience. [TAF Prev Med Bull 2009; 8(3.000: 217-222

  4. Transient analysis and burnout of high temperature superconducting current leads

    Science.gov (United States)

    Seol, S. Y.; Hull, J. R.

    The transient behaviour of high-temperature superconductor (HTS) current leads operated between liquid helium and liquid nitrogen temperatures is analysed for burnout conditions upon transition of the HTS into the normal state. Leads composed of HTS only and of HTS sheathed by pure silver or silver alloy are investigated numerically for temperature-dependent properties and analytically for temperature-independent properties. For lower values of shape factor (current density times length), the lead can be operated indefinitely without burnout. At higher values of shape factor, the lead reaches burnout in a finite time. With high current densities, the leads heat adiabatically. For a fixed shape factor, low current densities are desired to achieve long burnout times. To achieve a low helium boil-off rate in the superconducting state without danger of burnout, there is a preferred temperature dependence for thermal conductivity, and silver alloy sheaths are preferred to pure silver sheaths. However, for a given current density, pure silver sheaths take longer to burn out.

  5. The Study of Relations between Life Satisfaction, Burnout, Work Engagement and Hopelessness of High School Students

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    Çapri, Burhan; Gündüz, Bülent; Akbay, Sinem Evin

    2013-01-01

    The purpose of this research is to determine the relations between high school students' life satisfaction, burnout, work engagement and hopelessness scores and examine the contribution of their burnout, work engagement and hopelessness scores in the prediction of their life satisfaction scores. The Satisfaction with Life Scale (SWLS), Maslach…

  6. High rates of burnout among maternal health staff at a referral hospital in Malawi: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Meguid Tarek

    2011-05-01

    Full Text Available Abstract Background Burnout among maternal healthcare workers in sub-Saharan Africa may have a negative effect on services provided and efforts to mitigate high maternal mortality rates. In Malawi, research on burnout is limited and no empirical research has been conducted specifically among maternal health staff. Therefore, the aims of the study were to examine the prevalence and degree of burnout reported by healthcare workers who provide antenatal, intrapartum, and postnatal services in a district referral hospital in Malawi; and, to explore factors that may influence the level of burnout healthcare workers experience. Methods In the current cross-sectional study, levels of burnout among staff working in obstetrics and gynaecology at a referral hospital in Malawi were examined, in addition to individual and job characteristics that may be associated with burnout. Results In terms of the three dimensions of burnout, of the 101 participants, nearly three quarters (72% reported emotional exhaustion, over one third (43% reported depersonalization while almost three quarters (74% experienced reduced personal accomplishment. Conclusions Based on these findings, burnout appears to be common among participating maternal health staff and they experienced more burnout than their colleagues working in other medical settings and countries. Further research is needed to identify factors specific to Malawi that contribute to burnout in order to inform the development of prevention and treatment within the maternal health setting.

  7. High rates of burnout among maternal health staff at a referral hospital in Malawi: A cross-sectional study

    OpenAIRE

    2011-01-01

    Background Burnout among maternal healthcare workers in sub-Saharan Africa may have a negative effect on services provided and efforts to mitigate high maternal mortality rates. In Malawi, research on burnout is limited and no empirical research has been conducted specifically among maternal health staff. Therefore, the aims of the study were to examine the prevalence and degree of burnout reported by healthcare workers who provide antenatal, intrapartum, and postnatal serv...

  8. Current Situation of Job Burnout of Junior High School Teachers in Shangqiu Urban Areas and Its Relationship with Social Support

    Science.gov (United States)

    Song, Zhongying

    2008-01-01

    This study surveyed the current situation of teacher burnout in a sample of 400 teachers from urban junior high school in Shangqiu of Henan Province with scales, and examined the relationship between dimensions of teacher burnout and sources and types of social support they received. The results show that Shangqiu urban junior high school…

  9. Cross-level effects of high-performance work practices on burnout: Two counteracting mediating mechanisms compared

    NARCIS (Netherlands)

    Voorde, F.C. van de; Kroon, B.; Veldhoven, M.J.P.M. van

    2009-01-01

    Purpose - The purpose of this paper is to explore the impact of management practices - specifically, high-performance work practices (HPWPs) - on employee burnout. Two potential mediating mechanisms that counterbalance each other in the development of burnout are compared: a critical mechanism that

  10. A Positive Model for Reducing and Preventing School Burnout in High School Students

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    Aypay, Ayse

    2017-01-01

    This study aims to develop and test the validity of a model limited to attitude towards the future and subjective well-being for reducing and preventing the school burnout that high school students can experience. The study is designed as a relational screening model conducted over 389 high school students. The data in this study are analyzed…

  11. Burnout among High-School Students and Cannabis Use, Consumption Frequencies, Abuse and Dependence

    Science.gov (United States)

    Walburg, Vera; Moncla, Dany; Mialhes, Aurélie

    2015-01-01

    Background: Cannabis is a substance frequently consumed by adolescents, which is a risk factor for many psychopathological disorders. At the same time, adolescents in high-schools are likely to be exposed to significant stress from school that can sometimes lead to a burnout syndrome. Objective: The purpose of this study is to explore the impact…

  12. Burnout among High-School Students and Cannabis Use, Consumption Frequencies, Abuse and Dependence

    Science.gov (United States)

    Walburg, Vera; Moncla, Dany; Mialhes, Aurélie

    2015-01-01

    Background: Cannabis is a substance frequently consumed by adolescents, which is a risk factor for many psychopathological disorders. At the same time, adolescents in high-schools are likely to be exposed to significant stress from school that can sometimes lead to a burnout syndrome. Objective: The purpose of this study is to explore the impact…

  13. New Perspective of High-Pure Silicon

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@The discovery in the middle of 1950s of the semi-con ducting properties of crystalline silicon has led to the impetu ous development of electric power facilities, the sun-power industry, and particularly, the microelectronic industry. The increasing demand for the high-pure silicon requires the production of synthetic crystals. The raw material for the syn thetic crystals, the so-called technical, or metallurgical silicon, is obtained from quartzite and quartz of superior quality by means of carbon-thermal reduction of silicon using an electric arc discharge. The complexity of the technological process, high cost of the related facilities, worsening environmental pollution, and narrow-mindedness of a raw material company are attributed to the rise in price of the final product-silicon plates, resulting in the fall in the production of high-pure silicon, normally used in sun storage batteries.

  14. Burnout syndrome, working conditions, and health: a reality among public high school teachers in Brazil.

    Science.gov (United States)

    Santana, Ângela Maria C; De Marchi, Dione; Junior, Luiz C G; Girondoli, Yassana M; Chiappeta, Andrés

    2012-01-01

    The objective of the study was to evaluate the occurrence of Burnout Syndrome in 100 teachers of six public high schools and its correlation with working conditions in a southeast city of Brazil. Characterization of the sample occurred after application of a socio-demographic questionnaire. Evaluation of the working conditions was done by means of an Ergonomic Working Analysis. The presence of Burnout Syndrome was evaluated by means of the Maslach Burnout Inventory. The sample presented the predominance of women, with an average age of 40.4 and the majority married with children. Roughly 50% had less than 10 years of service, and more than half of the teachers taught more than 18 classes per week. Hoarseness after work was principally reported among women, which required many days off for health treatment. Environmental conditions reflect inadequacy in relation to noise, light, humidity and temperature. Presence of pain in the upper limbs was especially high among women. Risk of musculoskeletal disorders in the upper limbs predominated as moderately important to significant. We also identified an average distance walked by teachers of 1.5 Km and an average of 4.2 Kg of school supplies carried between classes. The Burnout Syndrome presented a high score for depersonalization principally among men, but it has association with both sexes. Emotional exhaustion correlates with noise, depersonalization, and personal fulfillment, in addition to the high number of weekly lessons. It can be concluded that Burnout syndrome is present among teachers, principally in terms of depersonalization, deserving the attention of government officials and the schools, as well as the teachers themselves.

  15. Job Burnout.

    Science.gov (United States)

    Angerer, John M.

    2003-01-01

    Presents an overview of job burnout, discusses the pioneering research and current theories of the burnout construct, along with the history of the main burnout assessment--the Maslach Burnout Inventory. Concludes that an understanding of the interaction between employee and his or her environment is critical for grasping the origin of burnout.…

  16. [Burnout in physicians].

    Science.gov (United States)

    Kurzthaler, Ilsemarie; Kemmler, Georg; Fleischhacker, W Wolfgang

    2017-06-01

    Burnout is a syndrome characterized by emotional exhaustion, depersonalization and low personal accomplishment. The primary objective of this study was to investigate both the prevalence and severity of burnout symptoms in a sample of clinical physicians from different speciality disciplines. A total of 69 clinical physicians ≤55 years who are working at the Medical University/regional Hospital Innsbruck were included into a cross-sectional study. Next to the assessment of sociodemographic and work-related variables the Maslach Burnout Inventory (MBI) was used to investigate burnout symtoms. Overall, 8.8% of the study population showed high emotional exhaustion with high or moderate depersonalization and low personal accomplishment and therefore had a high risk to develop a burnout syndrom. 11.8% showed a moderade burnout risk. Neither sociodemographic variables nor the degree of educational qualification or speciality discipline had an influence on burnout symptoms. However, there was a positive correlation between scientific activity and personal accomplihment. Our results suggest that the dimension of burnout symtoms among clinical physicians in Austria has be taken seriously. Further research is needed to develop specific programs in terms of burnout prevention and burnout therapy.

  17. Burnout in Premedical Undergraduate Students

    Science.gov (United States)

    Young, Christina; Fang, Daniel; Golshan, Shah; Moutier, Christine; Zisook, Sidney

    2012-01-01

    Background: There has been growing recognition that medical students, interns, residents and practicing physicians across many specialties are prone to burnout, with recent studies linking high rates of burnout to adverse mental health issues. Little is known about the trajectory and origins of burnout or whether its roots may be traced to earlier…

  18. Burnout in Premedical Undergraduate Students

    Science.gov (United States)

    Young, Christina; Fang, Daniel; Golshan, Shah; Moutier, Christine; Zisook, Sidney

    2012-01-01

    Background: There has been growing recognition that medical students, interns, residents and practicing physicians across many specialties are prone to burnout, with recent studies linking high rates of burnout to adverse mental health issues. Little is known about the trajectory and origins of burnout or whether its roots may be traced to earlier…

  19. A Photographic study of subcooled flow boiling burnout at high heat flux and velocity

    Energy Technology Data Exchange (ETDEWEB)

    Celata, G.P.; Mariani, A.; Zummo, G. [ENEA, National Institute of Thermal-Fluid Dynamics, Rome (Italy); Cumo, M. [University of Rome (Italy); Gallo, D. [University of Palermo (Italy). Department of Nuclear Engineering

    2007-01-15

    The present paper reports the results of a visualization study of the burnout in subcooled flow boiling of water, with square cross section annular geometry (formed by a central heater rod contained in a duct characterized by a square cross section). The coolant velocity is in the range 3-10m/s. High speed movies of flow pattern in subcooled flow boiling of water from the onset of nucleate boiling up to physical burnout of the heater are recorded. From video images (single frames taken with a stroboscope light and an exposure time of 1{mu}s), the following general behaviour of vapour bubbles was observed: when the rate of bubble generation is increasing, with bubbles growing in the superheated layer close to the heating wall, their coalescence produces a type of elongated bubble called vapour blanket. One of the main features of the vapour blanket is that it is rooted to the nucleation site on the heated surface. Bubble dimensions are given as a function of thermal-hydraulic tested conditions for the whole range of velocity until the burnout region. A qualitative analysis of the behaviour of four stainless steel heater wires with different macroscopic surface finishes is also presented, showing the importance of this parameter on the dynamics of the bubbles and on the critical heat flux. (author)

  20. Silicon carbide, an emerging high temperature semiconductor

    Science.gov (United States)

    Matus, Lawrence G.; Powell, J. Anthony

    1991-01-01

    In recent years, the aerospace propulsion and space power communities have expressed a growing need for electronic devices that are capable of sustained high temperature operation. Applications for high temperature electronic devices include development instrumentation within engines, engine control, and condition monitoring systems, and power conditioning and control systems for space platforms and satellites. Other earth-based applications include deep-well drilling instrumentation, nuclear reactor instrumentation and control, and automotive sensors. To meet the needs of these applications, the High Temperature Electronics Program at the Lewis Research Center is developing silicon carbide (SiC) as a high temperature semiconductor material. Research is focussed on developing the crystal growth, characterization, and device fabrication technologies necessary to produce a family of silicon carbide electronic devices and integrated sensors. The progress made in developing silicon carbide is presented, and the challenges that lie ahead are discussed.

  1. Epitaxial Growth of High-Quality Silicon Films on Double-Layer Porous Silicon

    Institute of Scientific and Technical Information of China (English)

    黄宜平; 竺士炀; 李爱珍; 王瑾; 黄靖云; 叶志镇

    2001-01-01

    The epitaxial growth of a high-quality silicon layer on double-layer porous silicon by ultra-high vacuum/chemical vapour deposition has been reported. The two-step anodization process results in a double-layer porous silicon structure with a different porosity. This double-layer porous silicon structure and an extended low-temperature annealing in a vacuum system was found to be helpful in subsequent silicon epitaxial growth. X-ray diffraction,cross-sectional transmission electron microscopy and spreading resistance testing were used in this work to study the properties of epitaxial silicon layers grown on the double-layer porous silicon. The results show that the epitaxial silicon layer is of good crystallinity and the same orientation with the silicon substrate and the porous silicon layer.

  2. Silicon Carbide Nanotube Oxidation at High Temperatures

    Science.gov (United States)

    Ahlborg, Nadia; Zhu, Dongming

    2012-01-01

    Silicon Carbide Nanotubes (SiCNTs) have high mechanical strength and also have many potential functional applications. In this study, SiCNTs were investigated for use in strengthening high temperature silicate and oxide materials for high performance ceramic nanocomposites and environmental barrier coating bond coats. The high · temperature oxidation behavior of the nanotubes was of particular interest. The SiCNTs were synthesized by a direct reactive conversion process of multiwall carbon nanotubes and silicon at high temperature. Thermogravimetric analysis (TGA) was used to study the oxidation kinetics of SiCNTs at temperatures ranging from 800degC to1300degC. The specific oxidation mechanisms were also investigated.

  3. Factors Affecting Burnout and School Engagement among High School Students: Study Habits, Self- Efficacy Beliefs, and Academic Success

    Science.gov (United States)

    Bilge, Filiz; Tuzgol Dost, Meliha; Cetin, Bayram

    2014-01-01

    This study examines high school students' levels of burnout and school engagement with respect to academic success, study habits, and self-efficacy beliefs. The data were gathered during the 2011-2012 school year from 633 students attending six high schools located in Ankara, Turkey. The analyses were conducted on responses from 605 students. The…

  4. Sharp burnout failure observed in high current-carrying double-walled carbon nanotube fibers

    Science.gov (United States)

    Song, Li; Toth, Geza; Wei, Jinquan; Liu, Zheng; Gao, Wei; Ci, Lijie; Vajtai, Robert; Endo, Morinobu; Ajayan, Pulickel M.

    2012-01-01

    We report on the current-carrying capability and the high-current-induced thermal burnout failure modes of 5-20 µm diameter double-walled carbon nanotube (DWNT) fibers made by an improved dry-spinning method. It is found that the electrical conductivity and maximum current-carrying capability for these DWNT fibers can reach up to 5.9 × 105 S m - 1 and over 1 × 105 A cm - 2 in air. In comparison, we observed that standard carbon fiber tended to be oxidized and burnt out into cheese-like morphology when the maximum current was reached, while DWNT fiber showed a much slower breakdown behavior due to the gradual burnout in individual nanotubes. The electron microscopy observations further confirmed that the failure process of DWNT fibers occurs at localized positions, and while the individual nanotubes burn they also get aligned due to local high temperature and electrostatic field. In addition a finite element model was constructed to gain better understanding of the failure behavior of DWNT fibers.

  5. Burnout in transplant nurses.

    Science.gov (United States)

    Jesse, Michelle T; Abouljoud, Marwan S; Hogan, Kathy; Eshelman, Anne

    2015-09-01

    Context-Burnout is a response to chronic strain within the workplace and is common across nursing professions. Little has been published about burnout in organ transplant nurses. Objective-To report the prevalence of the 3 main components of burnout (emotional exhaustion, depersonalization, and reduced personal accomplishment) in organ transplant nurses and to examine factors that contribute to the development of burnout in transplant nurses. Design-Cross-sectional survey of transplant nurses (recruited via listservs) on professional and personal demographics, decisional authority, psychological job demands, supervisor and coworker support, frequency and comfort with difficult patient interactions, and burnout. Participants-369 transplant nurses. Results-About half reported high levels of emotional exhaustion, 15.7% reported high levels of depersonalization, and 51.8% reported low levels of personal accomplishment. Working more hours per week, lower decisional authority, greater psychological job demands, lower perceived supervisor support, and greater frequency and discomfort with difficult patient interactions were significant predictors of emotional exhaustion. Greater frequency and discomfort with difficult patient interactions were significant predictors of depersonalization. Younger age, lower decisional authority, and greater discomfort with difficult patient interactions were predictors of low personal accomplishment. Conclusions-The study provides strong evidence of the presence of burnout in transplant nurses and opportunities for focused and potentially very effective interventions aimed at reducing burnout.

  6. High Heat Flux Burnout in Subcooled Flow Boiling

    Institute of Scientific and Technical Information of China (English)

    G.P.Celata; M.Cumo; 等

    1995-01-01

    The paper reports the results of an experimental research carried out at the Heat transfer divison of the Energy Department,C.R.Casaccia,on the thermal hydraulic characterization of subcooled flow boiling CHF under typical conditions of thermonuclear fusion reactors.I.e.high liquid velocity and subcooling.The experiment was carried out exploring the following parameters:channel diameter(from 2.5to 8.0 mm),heated length(10 and 15cm) ,liquid velocity (from 2 to 40m/s),exit pressure(from atmospheric to 5.0 MPa),inlet temperature(from 30 to 80℃),channel orientation (vertical and horizontal),A maximum CHF value of 60.6MW/m2 has been obtained under the following conditions:Tin-30°,p=2.5MPa,u=40m/s,D=2.5mm(smooth channel) Turbulence promoters(helically coiled wires)have been employed to further enhance the CHF attainable with subcooled flow boiling.Helically coiled wires allow an increase of 50% of the maximum CHF obtained with smooth channels.

  7. Burnout: need help?

    Directory of Open Access Journals (Sweden)

    Sari Azade

    2008-12-01

    Full Text Available Abstract Background Burnout syndrome is a psychological situation induced with working, especially in high-risk parts of the hospitals that affects the physical and mental conditions of the staff. The aim is to identify the characteristics of the staff related to Burnout Syndrome in the Emergency Department (ED. Methods The study includes the Maslach Burnout Inventory and other new individual research questions. The responders were the volunteers and comprised physicians, nurses, nurses' aides from EDs of all urban state hospitals of Adana (43.3%. Burnout scores were analyzed with regard to individual characteristics; supplementary work, marital status, the number of children, occupation, salary, career satisfaction, satisfaction in private life. Mann-Whitney U test and Kruskall-Wallis test were performed using SPSS 15.00. Results There were no relation between Burnout scores and supplementary work, marital status, number of children, occupation, salary, private life satisfaction, except for career satisfaction. Conclusion Presence and severity of Burnout syndrome were linked to career satisfaction without personal features and salaries. All branches of healthcare occupations in ED seem to have been affected by Burnout Syndrome similarly.

  8. Effect of Solution Focused Group Counseling for High School Students in Order to Struggle with School Burnout

    Science.gov (United States)

    Ates, Bünyamin

    2016-01-01

    In this research, the effect of solution focused group counseling upon high school students struggling with school burnout was analyzed. The research was an experimental study in which a pre-test post-test control group random design was used, depending upon the real experimental model. The study group included 30 students that volunteered from…

  9. [Burnout in nursing residents].

    Science.gov (United States)

    Franco, Gianfábio Pimentel; de Barros, Alba Lúcia Bottura Leite; Nogueira-Martins, Luiz Antônio; Zeitoun, Sandra Salloum

    2011-03-01

    Nursing residents may experience physical and emotional exhaustion from the daily life of attending the Program. The aim of this study was to determine the Burnout incidence among Nursing Residents. An investigative, descriptive, analytical, longitudinal-prospective study was conducted with 16 Residents over two years. The Maslach Burnout Inventory was used, translated and validated for Brazil, as well as a sociodemographic/occupational data tool. Of all residents, 17.2% showed high rates in Emotional Exhaustion and Depersonalization; 18.8% showed impaired commitment in Personal Accomplishment, 75% of which belonged to specialty areas, such as Emergency Nursing, Adult and Pediatric Intensive Care. Age and specialty area were positively correlated with Personal Accomplishment. One of the Residents was identified with changes in three subscales of the Maslach Burnout Inventory, thus characterized as a Burnout Syndrome patient. Nursing Residents have profiles of disease. Knowing these factors can minimize health risks of these workers.

  10. High-Index Contrast Silicon Rich Silicon Nitride Optical Waveguides and Devices

    DEFF Research Database (Denmark)

    Philipp, Hugh Taylor

    2004-01-01

    This research focused on the realization of high-density integrated optical devices made with high-index contrast waveguides. The material platform used for to develop these devices was modeled after standard silicon on silicon technology. The high-index waveguide core material was silicon rich...... silicon nitride. This provided a sharp contrast with silica and made low-loss waveguide bending radii less than 25mm possible. An immediate consequence of such small bending radii is the ability to make practical ring resonator based devices with a large free spectral range. Several ring resonator based...

  11. Calidad de vida y estrés laboral: la incidencia del Burnout en el deporte de alto rendimiento madrileño. Quality of life and job stress: Burnout among high performance sport professionals from Madrid.

    Directory of Open Access Journals (Sweden)

    Martínez del Castillo, Jesús

    2007-01-01

    Full Text Available ResumenEn la literatura sobre la psicología de la salud en las organizaciones es generalmente aceptado que el Burnout (Síndrome de quemarse por el trabajo aparece como consecuencia de un estrés laboral crónico excesivo que provoca una disminución de la habilidad en el desempeño de la actividad profesional y la aparición de diferentes problemas de salud en quien lo padece. El Burnout (Síndrome de quemarse por el trabajo ha sido conceptualizado como un síndrome psicológico tridimensional de agotamiento emocional, despersonalización y baja realización personal en el trabajo. El propósito de este estudio es evaluar la presencia del Burnout en el colectivo de los profesionales del Alto Rendimiento Deportivo. Para ello se utilizó una muestra de 102 profesionales en activo empleados en 20 organizaciones representativas del fenómeno del Alto Rendimiento Deportivo de la ciudad de Madrid, España. Para medir la incidencia del Burnout (Síndrome de quemarse por el trabajo se utilizó el Inventario de Burnout de Maslach. Los resultados obtenidos en este colectivo fueron de un 37,25% con altos niveles de Burnout (Síndrome de quemarse por el trabajo, 50% con nivel intermedio y 12,75% con bajo nivel. Estos profesionales presentan mayores niveles de baja realización personal en el trabajo (26,47% y menores niveles de despersonalización (11,76% y agotamiento emocional (10,78%. También se encontraron diferencias en los niveles cuando fueron comparados con otros profesionales del deporte.AbstractIt is widely accepted in organizational and health psychology literatures that burnout is a consequence of chronic job stress wh+ºich causes an array of negative work related performance and health outcomes. Burnout was conceptualized as a 3-dimensional psychological syndrome consisting of emotional exhaustion, depersonalization and decreased personal accomplishment. The purpose of this study was to assess the presence of Burnout syndrome in High

  12. Burnout among English Language Teachers in Malaysia

    Science.gov (United States)

    Mukundan, Jayakaran; Khandehroo, Koroush

    2010-01-01

    The phenomenon of burnout has always been under scrutiny, especially with reference to the teachers and their demographics. This study has deliberately focused on the English teachers' burnout and its relation with their demographics of age and workload in Malaysia. The findings showed that burnout is evident at high levels in all dimensions. In…

  13. Amorphous silicon rich silicon nitride optical waveguides for high density integrated optics

    DEFF Research Database (Denmark)

    Philipp, Hugh T.; Andersen, Karin Nordström; Svendsen, Winnie Edith

    2004-01-01

    Amorphous silicon rich silicon nitride optical waveguides clad in silica are presented as a high-index contrast platform for high density integrated optics. Performance of different cross-sectional geometries have been measured and are presented with regards to bending loss and insertion loss...

  14. Amorphous silicon rich silicon nitride optical waveguides for high density integrated optics

    DEFF Research Database (Denmark)

    Philipp, Hugh T.; Andersen, Karin Nordström; Svendsen, Winnie Edith

    2004-01-01

    Amorphous silicon rich silicon nitride optical waveguides clad in silica are presented as a high-index contrast platform for high density integrated optics. Performance of different cross-sectional geometries have been measured and are presented with regards to bending loss and insertion loss....... A sample double ring add-drop filter is presented....

  15. Job burnout.

    Science.gov (United States)

    Maslach, C; Schaufeli, W B; Leiter, M P

    2001-01-01

    Burnout is a prolonged response to chronic emotional and interpersonal stressors on the job, and is defined by the three dimensions of exhaustion, cynicism, and inefficacy. The past 25 years of research has established the complexity of the construct, and places the individual stress experience within a larger organizational context of people's relation to their work. Recently, the work on burnout has expanded internationally and has led to new conceptual models. The focus on engagement, the positive antithesis of burnout, promises to yield new perspectives on interventions to alleviate burnout. The social focus of burnout, the solid research basis concerning the syndrome, and its specific ties to the work domain make a distinct and valuable contribution to people's health and well-being.

  16. High-performance silicon nanowire bipolar phototransistors

    Science.gov (United States)

    Tan, Siew Li; Zhao, Xingyan; Chen, Kaixiang; Crozier, Kenneth B.; Dan, Yaping

    2016-07-01

    Silicon nanowires (SiNWs) have emerged as sensitive absorbing materials for photodetection at wavelengths ranging from ultraviolet (UV) to the near infrared. Most of the reports on SiNW photodetectors are based on photoconductor, photodiode, or field-effect transistor device structures. These SiNW devices each have their own advantages and trade-offs in optical gain, response time, operating voltage, and dark current noise. Here, we report on the experimental realization of single SiNW bipolar phototransistors on silicon-on-insulator substrates. Our SiNW devices are based on bipolar transistor structures with an optically injected base region and are fabricated using CMOS-compatible processes. The experimentally measured optoelectronic characteristics of the SiNW phototransistors are in good agreement with simulation results. The SiNW phototransistors exhibit significantly enhanced response to UV and visible light, compared with typical Si p-i-n photodiodes. The near infrared responsivities of the SiNW phototransistors are comparable to those of Si avalanche photodiodes but are achieved at much lower operating voltages. Compared with other reported SiNW photodetectors as well as conventional bulk Si photodiodes and phototransistors, the SiNW phototransistors in this work demonstrate the combined advantages of high gain, high photoresponse, low dark current, and low operating voltage.

  17. Catastrophic degradation of the interface of epitaxial silicon carbide on silicon at high temperatures

    Science.gov (United States)

    Pradeepkumar, Aiswarya; Mishra, Neeraj; Kermany, Atieh Ranjbar; Boeckl, John J.; Hellerstedt, Jack; Fuhrer, Michael S.; Iacopi, Francesca

    2016-07-01

    Epitaxial cubic silicon carbide on silicon is of high potential technological relevance for the integration of a wide range of applications and materials with silicon technologies, such as micro electro mechanical systems, wide-bandgap electronics, and graphene. The hetero-epitaxial system engenders mechanical stresses at least up to a GPa, pressures making it extremely challenging to maintain the integrity of the silicon carbide/silicon interface. In this work, we investigate the stability of said interface and we find that high temperature annealing leads to a loss of integrity. High-resolution transmission electron microscopy analysis shows a morphologically degraded SiC/Si interface, while mechanical stress measurements indicate considerable relaxation of the interfacial stress. From an electrical point of view, the diode behaviour of the initial p-Si/n-SiC junction is catastrophically lost due to considerable inter-diffusion of atoms and charges across the interface upon annealing. Temperature dependent transport measurements confirm a severe electrical shorting of the epitaxial silicon carbide to the underlying substrate, indicating vast predominance of the silicon carriers in lateral transport above 25 K. This finding has crucial consequences on the integration of epitaxial silicon carbide on silicon and its potential applications.

  18. Generation of high harmonics from silicon

    CERN Document Server

    Vampa, Giulio; Thiré, Nicolas; Schmidt, Bruno E; Légaré, Francois; Klug, Dennis D; Corkum, Paul B

    2016-01-01

    We generate high-order harmonics of a mid-infrared laser from a silicon single crystal and find their origin in the recollision of coherently accelerated electrons with their holes, analogously to the atomic and molecular case, and to ZnO [Vampa et al., Nature 522, 462-464 (2015)], a direct bandgap material. Therefore indirect bandgap materials are shown to sustain the recollision process as well as direct bandgap materials. Furthermore, we find that the generation is perturbed with electric fields as low as 30 V/$\\mu$m, equal to the DC damage threshold. Our results extend high-harmonic spectroscopy to the most technologically relevant material, and open the possibility to integrate high harmonics with conventional electronics.

  19. High temperature deformation of silicon steel

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Calvillo, Pablo, E-mail: pablo.rodriguez@ctm.com.es [CTM - Technologic Centre, Materials Technology Area, Manresa, Cataluna (Spain); Department of Materials Science and Metallurgical Engineering, Universidad Politecnica de Cataluna, Barcelona (Spain); Houbaert, Yvan, E-mail: Yvan.Houbaert@UGent.be [Department of Materials Science and Engineering, University of Ghent (Belgium); Petrov, Roumen, E-mail: Roumen.Petrov@ugent.be [Department of Materials Science and Engineering, University of Ghent (Belgium); Kestens, Leo, E-mail: Leo.kestens@ugent.be [Department of Materials Science and Engineering, University of Ghent (Belgium); Colas, Rafael, E-mail: rafael.colas@uanl.edu.mx [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, Universidad Autonoma de Nuevo Leon (Mexico)

    2012-10-15

    The microstructure and texture development during high temperature plane strain compression of 2% in weight silicon steel was studied. The tests were carried out at a constant strain rate of 5 s{sup -1} with reductions of 25, 35 and 75% at temperatures varying from 800 to 1100 Degree-Sign C. The changes in microstructure and texture were studied by means of scanning electron microscopy and electron backscattered diffraction. The microstructure close to the surface of the samples was equiaxed, which is attributed to the shear caused by friction, whereas that at the centre of the specimens was made of a mixture of elongated and fine equiaxed grains, the last ones attributed to the action of dynamic recovery followed by recrystallization. It was found that the volume fraction of these equiaxed grains augmented as reduction and temperature increased; a 0.7 volume fraction was accomplished with a 75% reduction at 1100 Degree-Sign C. The texture of the equiaxed and elongated grains was found to vary with the increase of deformation and temperature, as the {gamma}-fibre tends to disappear and the {alpha}-fibre to increase towards the higher temperature range. -- Highlights: Black-Right-Pointing-Pointer The plastic deformation of a silicon containing steel is studied by plane strain compression. Black-Right-Pointing-Pointer Equiaxed and elongated grains develop in different regions of the sample due to recrystallization. Black-Right-Pointing-Pointer Texture, by EBSD, is revealed to be similar in either type of grains.

  20. Production of high specific activity silicon-32

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, D.R. [Los Alamos National Lab., NM (United States); Brzezinski, M.A. [Univ. of California, Santa Barbara, CA (United States). Marine Biotechnology Center

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development Project (LDRD) at Los Alamos National Laboratory (LANL). There were two primary objectives for the work performed under this project. The first was to take advantage of capabilities and facilities at Los Alamos to produce the radionuclide {sup 32}Si in unusually high specific activity. The second was to combine the radioanalytical expertise at Los Alamos with the expertise at the University of California to develop methods for the application of {sup 32}Si in biological oceanographic research related to global climate modeling. The first objective was met by developing targetry for proton spallation production of {sup 32}Si in KCl targets and chemistry for its recovery in very high specific activity. The second objective was met by developing a validated field-useable, radioanalytical technique, based upon gas-flow proportional counting, to measure the dynamics of silicon uptake by naturally occurring diatoms.

  1. Evaluation of burnout syndrome in oncology employees.

    Science.gov (United States)

    Demirci, Senem; Yildirim, Yasemin Kuzeyli; Ozsaran, Zeynep; Uslu, Ruchan; Yalman, Deniz; Aras, Arif B

    2010-09-01

    Burnout is an important occupational problem for health care workers. We aimed to assess the burnout levels among oncology employees and to evaluate the sociodemographic and occupational factors contributing to burnout levels. The Maslach Burnout Inventory, which is designed to measure the three stages of burnout-emotional exhaustion (EE), depersonalization (DP), and personal accomplishment (PA), was used. The study sample consisted of 90 participants with a median age of 34 (range 23-56). The mean levels of burnout in EE, DP and PA stages were 23.80 +/- 10.98, 5.21 +/- 4.99, and 36.23 +/- 8.05, respectively, for the entire sample. Among the 90 participants, 42, 20, and 35.6% of the employees had high levels of burnout in the EE, DP, and PA substage, respectively. Sociodemographic and occupational factors associated with higher levels of burnout included age of less than 35, being unmarried, being childless, >40 work hours per week, working on night shifts, and burnout. Furthermore, employees who are not pleased with working in oncology field, who would like to change their specialty if they have an opportunity, and whose family and social lives have been negatively affected by their work experienced higher levels of burnout. Burnout syndrome may influence physical and mental health of the employee and affects the quality of health care as well. Therefore, several individual or organizational efforts should be considered for dealing with burnout.

  2. Highly nonlinear photoluminescence threshold in porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Nayfeh, M. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Akcakir, O. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Therrien, J. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Yamani, Z. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Barry, N. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Yu, W. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Gratton, E. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    1999-12-27

    Porous silicon is excited using near-infrared femtosecond pulsed and continuous wave radiation at an average intensity of {approx}10{sup 6} W/cm{sup 2} (8x10{sup 10} W/cm{sup 2} peak intensity in pulsed mode). Our results demonstrate the presence of micron-size regions for which the intensity of the photoluminescence has a highly nonlinear threshold, rising by several orders of magnitude near this incident intensity for both the pulsed and continuous wave cases. These results are discussed in terms of stimulated emission from quantum confinement engineered intrinsic Si-Si radiative traps in ultrasmall nanocrystallites, populated following two-photon absorption. (c) 1999 American Institute of Physics.

  3. High pressure Raman scattering of silicon nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Khachadorian, Sevak; Scheel, Harald; Thomsen, Christian [Institut fuer Festkoerperphysik, Technische Universitaet Berlin, 10623 Berlin (Germany); Papagelis, Konstantinos [Materials Science Department, University of Patras, 26504 Patras (Greece); Colli, Alan [Nokia Research Centre, 21 J J Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Ferrari, Andrea C, E-mail: khachadorian@physik.tu-berlin.de [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom)

    2011-05-13

    We study the high pressure response, up to 8 GPa, of silicon nanowires (SiNWs) with {approx} 15 nm diameter, by Raman spectroscopy. The first order Raman peak shows a superlinear trend, more pronounced compared to bulk Si. Combining transmission electron microscopy and Raman measurements we estimate the SiNWs' bulk modulus and the Grueneisen parameters. We detect an increase of Raman linewidth at {approx} 4 GPa, and assign it to pressure induced activation of a decay process into LO and TA phonons. This pressure is smaller compared to the {approx} 7 GPa reported for bulk Si. We do not observe evidence of phase transitions, such as discontinuities or change in the pressure slopes, in the investigated pressure range.

  4. Preparation of Silicon Carbide with High Properties

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to prepare silicon carbide with high properties, three kinds of SiC powders A, B, and C with different composition and two kinds of additives, which were Y2O3-Al2O3 system and Y2O3-La2O3 system, were used in this experiment. The properties of hot-pressed SiC ceramics were measured. With the same additives, different SiC powder resulted in different properties. On the other hand, with the same SiC powder, increasing the amount of the additive Y2O3-Al2O3 improved properties of SiC ceramics at room temperature, and increasing the amount of the additive Y2O3-La2O3 improved property SiC ceramics at elevated temperature. In addition, the microstructure of SiC ceramics was studied by scanning electron microscopy.

  5. Effect of ash components on the ignition and burnout of high ash coals

    Energy Technology Data Exchange (ETDEWEB)

    Feng, B.; Yan, R.; Zheng, C.G. [Huazhong University of Science and Technology, Wuhan (China). National Laboratory of Coal Combustion

    1998-11-01

    The effect of the ash components on the ignition and burnout of four Chinese high ash coals were studied by thermogravimetric analysis. To investigate the influence of the ash components, comparative experiments were carried out with original, deashed and impregnated coals. Eleven types of ash components, such as SiO{sub 2}, CaCO{sub 3}, MgO, Na{sub 2}CO{sub 3}, K{sub 2}CO{sub 3}, Al{sub 2}O{sub 3}, TiO{sub 2}, Fe{sub 2}O{sub 3}, FeS{sub 2}, NH{sub 4}Fe(SO{sub 4}){sub 2}{center_dot}12H{sub 2}O and FeSO{sub 4},(NH{sub 4}){center_dot}6H{sub 2}O were used in the present study. It was found that most of the ash components have negative effects. The strong influence of some ash components suggests that the combustion characteristics of high ash coal may be determined by the ash composition. 5 refs., 2 figs., 2 tabs.

  6. Effect of High Coal Injection on Low Silicon Ironmaking Process

    Institute of Scientific and Technical Information of China (English)

    JIN Yong-long; XU Nan-ping; WU Shi-ying

    2003-01-01

    The effects of different coal ratios and reaction temperatures on silicon content in hot metal were studied under the condition of high powder coal injection (PCI) ratio in laboratory. The samples of coke taken from tuyere were analyzed by chemical methods. According to the remnant silicon dioxide in different samples, the effect of PCI ratio on silicon content in hot metal was studied in tuyere area. The results can not only certify the traditional theory, but also explain the relation between high PCI ratio and low silicon.

  7. Micro-machined high capacity silicon load cells

    NARCIS (Netherlands)

    Zwijze, A.F.

    2000-01-01

    The aim of the research presented in this thesis is to improve the performance of high capacity conventional load cells or force sensors by using silicon as the base material. Silicon is used because it offers the possibility of realising small, light, low cost and high performance mechanical sensor

  8. High Detectivity Graphene-Silicon Heterojunction Photodetector.

    Science.gov (United States)

    Li, Xinming; Zhu, Miao; Du, Mingde; Lv, Zheng; Zhang, Li; Li, Yuanchang; Yang, Yao; Yang, Tingting; Li, Xiao; Wang, Kunlin; Zhu, Hongwei; Fang, Ying

    2016-02-01

    A graphene/n-type silicon (n-Si) heterojunction has been demonstrated to exhibit strong rectifying behavior and high photoresponsivity, which can be utilized for the development of high-performance photodetectors. However, graphene/n-Si heterojunction photodetectors reported previously suffer from relatively low specific detectivity due to large dark current. Here, by introducing a thin interfacial oxide layer, the dark current of graphene/n-Si heterojunction has been reduced by two orders of magnitude at zero bias. At room temperature, the graphene/n-Si photodetector with interfacial oxide exhibits a specific detectivity up to 5.77 × 10(13) cm Hz(1/2) W(-1) at the peak wavelength of 890 nm in vacuum, which is highest reported detectivity at room temperature for planar graphene/Si heterojunction photodetectors. In addition, the improved graphene/n-Si heterojunction photodetectors possess high responsivity of 0.73 A W(-1) and high photo-to-dark current ratio of ≈10(7) . The current noise spectral density of the graphene/n-Si photodetector has been characterized under ambient and vacuum conditions, which shows that the dark current can be further suppressed in vacuum. These results demonstrate that graphene/Si heterojunction with interfacial oxide is promising for the development of high detectivity photodetectors.

  9. Nursing burnout interventions: what is being done?

    Science.gov (United States)

    Henry, Barbara J

    2014-04-01

    Many studies have documented high prevalence of burnout and compassion fatigue in oncology nurses. Burnout has detrimental effects on nurses, patients, and healthcare organizations. However, burnout interventions have been shown to improve the physical and mental health of nurses, patient satisfaction, and the organizational bottom line by reducing associated costs of burnout. Although treatment centers may prevent and correct burnout in oncology nurses by providing various interventions, few articles focus on those interventions. This article compiles and describes interventions that will serve as a reference to nurses and healthcare organization leaders interested in implementing similar programs.

  10. Promoting an equitable and supportive school climate in high schools: the role of school organizational health and staff burnout.

    Science.gov (United States)

    Bottiani, Jessika H; Bradshaw, Catherine P; Mendelson, Tamar

    2014-12-01

    In response to persistent racial disparities in academic and behavioral outcomes between Black and White students, equitable school climate has drawn attention as a potential target for school reform. This study examined differences in Black and White students' experiences of school climate and explored whether indicators of school organizational health and staff burnout moderated differences in students' school experiences by race. Utilizing hierarchical linear modeling with a sample of 18,397 Black students (n=6228) and White students (n=12,169) and 2391 school staff in 53 schools, we found a consistent pattern of racial inequalities, such that Black students reported less positive experiences than White students across three indicators of school climate (caring γ=-0.08, porganizational health and student-reported school climate (e.g., staff affiliation and student-perceived equity, γ=0.07, porganizational health indicators were more strongly associated with positive perceptions of school climate among White students than Black students, translating into greater racial disparities in perceived school climate at schools with greater organizational health (e.g., supportive leadership by race on student-perceived engagement, γ=-0.03, p=.042). We also found negative associations between staff-reported burnout and students' experience of equity, such that the racial gap was smaller in schools with high ratings of burnout (γ=0.04, p=.002). These findings have implications for educators and education researchers interested in promoting school social contexts that equitably support student engagement and success.

  11. Delta-Doping at Wafer Level for High Throughput, High Yield Fabrication of Silicon Imaging Arrays

    Science.gov (United States)

    Hoenk, Michael E. (Inventor); Nikzad, Shoulch (Inventor); Jones, Todd J. (Inventor); Greer, Frank (Inventor); Carver, Alexander G. (Inventor)

    2014-01-01

    Systems and methods for producing high quantum efficiency silicon devices. A silicon MBE has a preparation chamber that provides for cleaning silicon surfaces using an oxygen plasma to remove impurities and a gaseous (dry) NH3 + NF3 room temperature oxide removal process that leaves the silicon surface hydrogen terminated. Silicon wafers up to 8 inches in diameter have devices that can be fabricated using the cleaning procedures and MBE processing, including delta doping.

  12. [Burnout syndrome: diagnosis, principles of treatment, prophylaxis].

    Science.gov (United States)

    Ovchinnikov, Yu V; Palchenkova, M V; Kalachev, O V

    2015-07-01

    Burnout syndrome is a socio-psychological phenomenon of emotional, motivational, and physical exhaustion as a result of chronic occupational stress. It is manifested as long-term emotional exhaustion, depersonalization and diminished personal and professional achievements. Burnout syndrome is common among health care workers, 'due to their high dedication, empathy for suffering patients, and decision-making related to life and health of patients. Personal, role and organizational factors influence on development of burnout. The clinical picture of burnout is multifactorial and can be described as a set of psychosomatic and somatic disorders, symptoms of social dysfunction. Diversity and non-specific symptoms of burnout syndrome determine the need for an interdisciplinary approach to its diagnosis. The leading role in solving problems related to stress and emotional burnout plays psychotherapy. The paper presents diagnostic criteria, risk factors, and methods of prevention and treatment of emotional burnout.

  13. Burnout and Doctors: Prevalence, Prevention and Intervention

    Directory of Open Access Journals (Sweden)

    Shailesh Kumar

    2016-06-01

    Full Text Available Doctors are exposed to high levels of stress in the course of their profession and are particularly susceptible to experiencing burnout. Burnout has far-reaching implications on doctors; patients and the healthcare system. Doctors experiencing burnout are reported to be at a higher risk of making poor decisions; display hostile attitude toward patients; make more medical errors; and have difficult relationships with co-workers. Burnout among doctors also increases risk of depression; anxiety; sleep disturbances; fatigue; alcohol and drug misuse; marital dysfunction; premature retirement and perhaps most seriously suicide. Sources of stress in medical practice may range from the emotions arising in the context of patient care to the environment in which doctors practice. The extent of burnout may vary depending on the practice setting; speciality and changing work environment. Understanding dynamic risk factors associated with burnout may help us develop strategies for preventing and treating burnout. Some of these strategies will be reviewed in this paper.

  14. Burnout and Doctors: Prevalence, Prevention and Intervention.

    Science.gov (United States)

    Kumar, Shailesh

    2016-06-30

    Doctors are exposed to high levels of stress in the course of their profession and are particularly susceptible to experiencing burnout. Burnout has far-reaching implications on doctors; patients and the healthcare system. Doctors experiencing burnout are reported to be at a higher risk of making poor decisions; display hostile attitude toward patients; make more medical errors; and have difficult relationships with co-workers. Burnout among doctors also increases risk of depression; anxiety; sleep disturbances; fatigue; alcohol and drug misuse; marital dysfunction; premature retirement and perhaps most seriously suicide. Sources of stress in medical practice may range from the emotions arising in the context of patient care to the environment in which doctors practice. The extent of burnout may vary depending on the practice setting; speciality and changing work environment. Understanding dynamic risk factors associated with burnout may help us develop strategies for preventing and treating burnout. Some of these strategies will be reviewed in this paper.

  15. Low cost routes to high purity silicon and derivatives thereof

    Energy Technology Data Exchange (ETDEWEB)

    Laine, Richard M; Krug, David James; Marchal, Julien Claudius; Mccolm, Andrew Stewart

    2013-07-02

    The present invention is directed to a method for providing an agricultural waste product having amorphous silica, carbon, and impurities; extracting from the agricultural waste product an amount of the impurities; changing the ratio of carbon to silica; and reducing the silica to a high purity silicon (e.g., to photovoltaic silicon).

  16. Intraocular inflammation following endotamponade with high-density silicone oil.

    NARCIS (Netherlands)

    Theelen, T.; Tilanus, M.A.D.; Klevering, B.J.

    2004-01-01

    BACKGROUND: The use of a mixture of silicone oil and partially fluorinated alkanes (high-density silicone oil) has recently been suggested as intraocular tamponade in complicated retinal detachment of the inferior quadrants. We describe a series of patients who developed a clinical picture resemblin

  17. SYNTHESIS OF HIGH THERMOSTABLE SILICONE GELS CONSTRUCTED WITH LADDERLIKE POLYSILSESQUIOXANES

    Institute of Scientific and Technical Information of China (English)

    Huai-zhong Pan; Ming Cao; Jian-hua Luo; Ping Xie; Rong-ben Zhang; Yu-hui Lin; Neal Tai-sheng Chung

    2000-01-01

    Heat-resistant silicone gels were synthesized by replacing the single main chain polymethylhydrosiloxane with reactive ladderlike polyhydrosilsesquioxane copolymers. Because of the interaction between polydimethylsiloxane chains and the ladderlike polysilsesquioxanes chains, the cyclization of the polydimethylsiloxane chains is hindered. The high thermal stability of the ladderlike polymers can improve the thermal stability of the silicone gels without sacrificing their good comprehensive properties.

  18. A review of high-efficiency silicon solar cells

    Science.gov (United States)

    Rohatgi, A.

    1986-01-01

    Various parameters that affect solar cell efficiency were discussed. It is not understood why solar cells produced from less expensive Czochralski (Cz) silicon are less efficient than cells fabricated from more expensive float-zone (Fz) silicon. Performance characteristics were presented for recently produced, high-efficient solar cells fabricated by Westinghouse Electric Corp., Spire Corp., University of New South Wales, and Stanford University.

  19. Intraocular inflammation following endotamponade with high-density silicone oil.

    NARCIS (Netherlands)

    Theelen, T.; Tilanus, M.A.D.; Klevering, B.J.

    2004-01-01

    BACKGROUND: The use of a mixture of silicone oil and partially fluorinated alkanes (high-density silicone oil) has recently been suggested as intraocular tamponade in complicated retinal detachment of the inferior quadrants. We describe a series of patients who developed a clinical picture

  20. Burnout in medical residents: a questionnaire and interview study.

    Science.gov (United States)

    Ringrose, Rik; Houterman, Saskia; Koops, Willem; Oei, Guid

    2009-08-01

    High burnout levels have been observed in medical residents. The purpose of this study is to assess the burnout rates and potential determinants of burnout in a sample of medical residents. In total, 58 medical residents working in a Dutch teaching hospital, received questionnaires at home, including the Maslach Burnout Inventory (MBI). In addition, they were asked for an in-depth interview to investigate the relevant indicators for developing burnout. In total, 47 residents responded (81%) from which 15 (31%) met the MBI criteria for burnout. Work-family conflict, work-related autonomy and level of work-engagement were significantly associated with burnout. Ten respondents were interviewed; none of those reported any serious burnout symptoms but two met the criteria for burnout. In this study, burnout rates from questionnaires and interviews in medical residents are not consistent. Regular burnout screenings and performing interviews are recommended in addition to burnout questionnaires, in order to efficiently identify residents at risk for burnout. This allows improved monitoring of a resident's mental state thus facilitating prevention of escalating burnout symptoms. Future research could focus on preventive factors for developing burnout.

  1. Affect generated by social comparisons among nurses high and low in burnout

    NARCIS (Netherlands)

    Buunk, BP; Ybema, JF; van der Zee, K

    2001-01-01

    The affective consequences of social comparison were examined in 2 field studies among nurses and related to the 3 dimensions of professional burnout: emotional exhaustion, reduced personal accomplishment, and depersonalization. Study 1 was conducted in a sample of 99 nurses of a psychiatric hospita

  2. [Job burnout: focusing on occupational differences of enthusiasm for job].

    Science.gov (United States)

    Igawa, Junichi; Nakanishi, Daisuke; Shiwa, Shiro

    2013-10-01

    This study investigates characteristics of burnout, as related to job descriptions in mental hospitals and presuppositions of the concept of burnout (burnout is caused as a result of having enthusiasm for a job). The results of a questionnaire survey (burnout tendency, Japanese Burnout Scale, enthusiasm for a job in the past, modified Enthusiasm scale) with 781 workers at mental hospitals showed that burnout characteristics varied according to job descriptions. Specifically, psychiatric social workers, medical assistants, and nurses fell into the high-burnout category, whereas doctors, occupational therapists, and pharmacists fell into the low-burnout category. In addition, in order to compare enthusiasm for a job in the past with current burnout tendencies, factor scores for the respective scales were classified into a low group or a high group and were cross tabulated. The numbers in the cells of the groups indicating the opposite of the definition of burnout (low enthusiasm-high burnout tendency, high enthusiasm-low burnout tendency) were larger. This indicates that having enthusiasm for a job is not a direct factor for burnout, which is different from the presupposition about burnout.

  3. Recent Progress in Silicon Electro-optic Modulators for High Speed Applications

    Institute of Scientific and Technical Information of China (English)

    XIAO Xi; YU Jin-zhong

    2008-01-01

    Silicon-based high-speed electro-optical modulator is the key component of silicon photonics for future communiction and interconnection systems. In this paper, introduced are the optical mudulation mechanisms in silicon, reviewed are some recent progresses in high-speed silicon modulators, and analyzed are advantages and shortages of the silicon modulators of different types.

  4. Self-Healing, High-Permittivity Silicone Dielectric Elastomer

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Yu, Liyun; Skov, Anne Ladegaard

    2016-01-01

    or cuts made directly to the material due to the reassembly of the ionic bonds that are broken during damage. The dielectric elastomers presented in this paper pave the way to increased lifetimes and the ability of dielectric elastomers to survive millions of cycles in high-voltage conditions....... possesses high dielectric permittivity and consists of an interpenetrating polymer network of silicone elastomer and ionic silicone species that are cross-linked through proton exchange between amines and acids. The ionically cross-linked silicone provides self-healing properties after electrical breakdown...

  5. What Is Caregiver Burnout?

    Science.gov (United States)

    ... heart Lifestyle + Risk Reduction Caregiving What Is Caregiver Burnout? Caregiver burnout is caused by too much long-term stress. ... themselves. They begin to show signs of caregiver burnout. Your healthy body, mind and spirit benefit your ...

  6. Silicon nitride ceramic having high fatigue life and high toughness

    Science.gov (United States)

    Yeckley, Russell L.

    1996-01-01

    A sintered silicon nitride ceramic comprising between about 0.6 mol % and about 3.2 mol % rare earth as rare earth oxide, and between about 85 w/o and about 95 w/o beta silicon nitride grains, wherein at least about 20% of the beta silicon nitride grains have a thickness of greater than about 1 micron.

  7. Theory of High Frequency Rectification by Silicon Crystals

    Science.gov (United States)

    Bethe, H. A.

    1942-10-29

    The excellent performance of British "red dot" crystals is explained as due to the knife edge contact against a polished surface. High frequency rectification depends critically on the capacity of the rectifying boundary layer of the crystal, C. For high conversion efficiency, the product of this capacity and of the "forward" (bulk) resistance R {sub b} of the crystal must be small. For a knife edge, this product depends primarily on the breadth of the knife edge and very little upon its length. The contact can therefore have a rather large area which prevents burn-out. For a wavelength of 10 cm. the computations show that the breadth of the knife edge should be less than about 10 {sup -3} cm. For a point contact the radius must be less than 1.5 x 10 {sup -3} cm. and the resulting small area is conducive to burn-out. The effect of "tapping" is probably to reduce the area of contact. (auth)

  8. Silicon carbide materials for high duty seal applications

    Energy Technology Data Exchange (ETDEWEB)

    Berroth, K.E. (Schunk Ingenieurkeramik GmbH, Duesseldorf (Germany, F.R.))

    1990-12-01

    Properties, fabrication, and high-duty applications of silicon carbide grades are discussed. The two types of silicon carbide, i.e., reaction-bonded and sintered, are considered. The potential for adhesion and the lack of dry running abilities lead to a variety of microstructures. For reaction-bonded silicon carbide, the microstructure can be a tool for optimization of the tribological behavior. Besides the high corrosion resistance of the material, its thermal conductivity is excellent. Grain sizes of about 40-50 microns are used in high-duty applications. Reaction-bonded silicon carbide with residual content of carbon graphite has improved tribological/hydrodynamic characteristics and performs well in sealing hard faces.

  9. High precision optical finishing of lightweight silicon carbide aspheric mirror

    Science.gov (United States)

    Kong, John; Young, Kevin

    2010-10-01

    Critical to the deployment of large surveillance optics into the space environment is the generation of high quality optics. Traditionally, aluminum, glass and beryllium have been used; however, silicon carbide becomes of increasing interest and availability due to its high strength. With the hardness of silicon carbide being similar to diamond, traditional polishing methods suffer from slow material removal rates, difficulty in achieving the desired figure and inherent risk of causing catastrophic damage to the lightweight structure. Rather than increasing structural capacity and mass of the substrate, our proprietary sub-aperture aspheric surface forming technology offers higher material removal rates (comparable to that of Zerodur or Fused Silica), a deterministic approach to achieving the desired figure while minimizing contact area and the resulting load on the optical structure. The technology performed on computer-controlled machines with motion control software providing precise and quick convergence of surface figure, as demonstrated by optically finishing lightweight silicon carbide aspheres. At the same time, it also offers the advantage of ideal pitch finish of low surface micro-roughness and low mid-spatial frequency error. This method provides a solution applicable to all common silicon carbide substrate materials, including substrates with CVD silicon carbide cladding, offered by major silicon carbide material suppliers. This paper discusses a demonstration mirror we polished using this novel technology. The mirror is a lightweight silicon carbide substrate with CVD silicon carbide cladding. It is a convex hyperbolic secondary mirror with 104mm diameter and approximately 20 microns aspheric departure from best-fit sphere. The mirror has been finished with surface irregularity of better than 1/50 wave RMS @632.8 nm and surface micro-roughness of under 2 angstroms RMS. The technology has the potential to be scaled up for manufacturing capabilities of

  10. Chronic job burnout and daily functioning: A theoretical analysis

    Directory of Open Access Journals (Sweden)

    Arnold B. Bakker

    2014-12-01

    Full Text Available In this article, we discuss the individual employee's role in the development of his/her job burnout. We review the antecedents and consequences of burnout, and propose a model with chronic burnout as a moderator of daily functioning in the workplace. Specifically, we argue that chronic burnout strengthens the loss cycle of daily job demands, daily exhaustion, and daily self-undermining. Additionally, we argue that chronic burnout weakens the gain cycle of daily job resources, daily work engagement, and daily job crafting. We conclude that employees with high levels of burnout need help in structurally changing their working conditions and health status.

  11. High aspect ratio transmission line circuits micromachined in silicon

    Science.gov (United States)

    Todd, Shane Truman

    The performance of complimentary metal-oxide-semiconductor (CMOS) monolithic microwave integrated circuits (MMICs) fabricated on silicon has improved dramatically. The scaling down of silicon transistors has increased the maximum frequency of transistors to the point where silicon MMICs have become a viable alternative to compound semiconductor MMICs in certain applications. A fundamental problem still exists in silicon MMICs however in that transmission lines fabricated on silicon can suffer from high loss due to the finite conductivity of the silicon substrate. A novel approach for creating low-loss transmission lines on silicon is presented in this work. Low-loss transmission lines are created on low resistivity silicon by using a micromachining method that combines silicon deep reactive ion etching (DRIE), thermal oxidation, electroplating, and planarization. Two types of high aspect ratio transmission lines are created with this method including high aspect ratio coplanar waveguide (hicoplanar) and semi-rectangular coaxial (semicoaxial). Transmission lines with impedances ranging from 20--80 O have been fabricated with minimum measured loss lower than 1 dB/cm at 67 GHz. Low-loss dielectrics are created for the high aspect ratio transmission lines using the mesa merging method. The mesa merging method works by creating silicon mesa arrays using DRIE and then converting and merging the mesa arrays into a solid oxide dielectric using thermal oxidation. The transmission lines are designed so that the fields penetrate the low-loss oxide dielectric and are isolated from the lossy silicon substrate. The mesa merging method has successfully created large volume oxide with depth up to 65 microm and width up to 240 microm in short oxidation times. Other advantages of the high aspect ratio transmission lines are demonstrated including low-loss over a wide impedance range, high isolation, and high coupling for coupled-line circuits. Transmission line models have been

  12. Burnout in nursing.

    Science.gov (United States)

    Patrick, Kent; Lavery, Judy F

    2007-01-01

    Previous research has suggested that organisational change can contribute to stress-related outcomes for workers. Burnout, one such stress-related outcome, has been conceptualised as a multidimensional construct consisting of emotional exhaustion, depersonalisation and reduced personal accomplishment. Many health care organisations have undergone substantial organisational change over the last decade. The purpose of this study was to assess levels of burnout in nurses and to ascertain if there were individual or work characteristics that were associated with this syndrome. Randomised survey methodology. Registered nurses (Division 1) in Victoria who were ANF members. A random sample of 574 Victorian ANF nurse members. The assessment of levels of burnout in Victorian ANF nurse members and the identification of individual or work characteristics that may be associated with it. Victorian ANF nurse members exhibited lower depersonalisation and higher personal accomplishment compared to medical and overall normative data. Increasing age and fewer working hours were associated with lower levels of emotional exhaustion and depersonalisation. Working overtime was positively associated with emotional exhaustion however further analyses demonstrated that those who worked overtime voluntarily did not differ from workers not working overtime. However feeling pressured/expected to work overtime was positively associated with emotional exhaustion and depersonalisation. Victorian ANF nurse members were not experiencing high levels of burnout. However the study highlighted the need for health care management to recognise the importance of working reasonable hours and in particular, to understand the potential detrimental effect that having to work pressured or unexpected overtime has on staff.

  13. A high-Tc superconductor bolometer on a silicon nitridemembrane

    NARCIS (Netherlands)

    Sanchez, S.; Elwenspoek, M.C.; Gui, C.; Nivelle, de M.J.M.E.; Vries, de R.; Korte, de P.A.J.; Bruijn, M.P.; Schwierzi, B.

    1997-01-01

    In this paper we describe the design, fabrication and performance of a high-Tc GdBa2Cu3O7-δ superconductor bolometer positioned on a 2×2 mm2, 1 μm thick silicon nitride membrane. The bolometer structure has an effective area of 0.64 mm2 and was grown on a specially developed silicon-on-nitride layer

  14. High efficiency silicon solar cell review

    Science.gov (United States)

    Godlewski, M. P. (Editor)

    1975-01-01

    An overview is presented of the current research and development efforts to improve the performance of the silicon solar cell. The 24 papers presented reviewed experimental and analytic modeling work which emphasizes the improvment of conversion efficiency and the reduction of manufacturing costs. A summary is given of the round-table discussion, in which the near- and far-term directions of future efficiency improvements were discussed.

  15. The Burden of Burnout.

    Science.gov (United States)

    Elmariah, Hany; Thomas, Samantha; Boggan, Joel C; Zaas, Aimee; Bae, Jonathan

    This study sought to determine burnout prevalence and factors associated with burnout in internal medicine residents after introduction of the 2011 ACGME duty hour rules. Burnout was evaluated using an anonymized, abbreviated version of the Maslach Burnout Inventory. Surveys were collected biweekly for 48 weeks during the 2013-2014 academic year. Burnout severity was compared across subgroups and time. A score of 3 or higher signified burnout. Overall, 944 of 3936 (24%) surveys were completed. The mean burnout score across all surveys was 2.8. Categorical residents had higher burnout severity than noncategorical residents (2.9 vs 2.7, P = .005). Postgraduate year 2 residents had the highest burnout severity by year (3.1, P burnout severity than residents on outpatient or consultation rotations (3.1 vs 2.2 vs 2.2, P Burnout remains a significant problem even with recent duty hour modifications.

  16. Burnout and Humor Usage among Community College Nursing Faculty Members.

    Science.gov (United States)

    Talbot, Laura A.

    2000-01-01

    Assesses the correlation of burnout among community college nursing faculty members and their use of humor to mediate academic stress related to burnout. Differences in burnout between high versus low humor usage respondents showed a higher sense of personal accomplishment with high humor usage. Of those with low humor usage, workload was related…

  17. From Teacher Burnout to Student Burnout

    Science.gov (United States)

    PP, Noushad

    2008-01-01

    Originally, Burnout was a common work related phenomena resulting of severe stress. Burnout is considered to be a long-term stress reaction that particularly occurs among professionals who work with people in some capacity--like teachers, nurses, or social workers. Although various definitions of burnout exist, it is most commonly described as a…

  18. Factors Influencing Teacher Burnout.

    Science.gov (United States)

    Raquepaw, Jayne; deHaas, Patricia A.

    Burnout is a syndrome of emotional exhaustion and cynicism frequently occurring among human services professionals. Education is one profession whose members are particularly susceptible to burnout. There is a need to identify causes of burnout and possible ameliorative strategies, as perceived by teachers. The Maslach Burnout Inventory (MBI), a…

  19. Factors Influencing Teacher Burnout.

    Science.gov (United States)

    Raquepaw, Jayne; deHaas, Patricia A.

    Burnout is a syndrome of emotional exhaustion and cynicism frequently occurring among human services professionals. Education is one profession whose members are particularly susceptible to burnout. There is a need to identify causes of burnout and possible ameliorative strategies, as perceived by teachers. The Maslach Burnout Inventory (MBI), a…

  20. Burnout Syndrome of Teachers

    OpenAIRE

    Semrádová, Michaela

    2013-01-01

    The bachelor's thesis covers burnout syndrome of teachers. Defines burnout syndrome, describes its causes and symptoms. Describes teaching as helping profession and focousing on stressful situations at school. In the last chapter described different prevention strategies burnout syndrome. Key words: burnout syndrome, teaching, teacher, helping professions, beginning teacher, stress

  1. Silicon-embedded copper nanostructure network for high energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Tianyue

    2016-03-15

    Provided herein are nanostructure networks having high energy storage, electrochemically active electrode materials including nanostructure networks having high energy storage, as well as electrodes and batteries including the nanostructure networks having high energy storage. According to various implementations, the nanostructure networks have high energy density as well as long cycle life. In some implementations, the nanostructure networks include a conductive network embedded with electrochemically active material. In some implementations, silicon is used as the electrochemically active material. The conductive network may be a metal network such as a copper nanostructure network. Methods of manufacturing the nanostructure networks and electrodes are provided. In some implementations, metal nanostructures can be synthesized in a solution that contains silicon powder to make a composite network structure that contains both. The metal nanostructure growth can nucleate in solution and on silicon nanostructure surfaces.

  2. Displacement damage effects in silicon MEMS at high proton doses

    Science.gov (United States)

    Gomes, João; Shea, Herbert R.

    2011-02-01

    We report on a study of the sensitivity of silicon MEMS to proton radiation and mitigation strategies. MEMS can degrade due to ionizing radiation (electron-hole pair creation) and non-ionizing radiation (displacement damage), such as electrons, trapped and solar protons, or cosmic rays, typically found in a space environment. Over the past few years there has been several reports on the effects of ionizing radiation in silicon MEMS, with failure generally linked to trapped charge in dielectrics. However there is near complete lack of studies on displacement damage effects in silicon- MEMS: how does silicon change mechanically due to proton irradiation? We report on an investigation on the susceptibility of 50 μm thick SOI-based MEMS resonators to displacement damages due to proton beams, with energies from 1 to 60 MeV, and annealing of this damage. We measure ppm changes on the Young's modulus and Poisson ratio by means of accurately monitoring the resonant frequency of devices in vacuum using a Laser Doppler Vibrometer. We observed for the first time an increase (up to 0.05%) of the Young's modulus of single-crystal silicon electromagnetically-actuated micromirrors after exposure to low energy protons (1-4 MeV) at high absorbed doses ~ 100 Mrad (Si). This investigation will contribute to a better understanding of the susceptibility of silicon-based MEMS to displacement damages frequently encountered in a space radiation environment, and allow appropriated design margin and shielding to be implemented.

  3. Occupational burnout among nursing personel

    Directory of Open Access Journals (Sweden)

    Sylwia Wieder-Huszla

    2016-02-01

    Full Text Available Background. Occupational stress and the related burnout syndrome is undoubtedly one of the most important challenges for public health. Objectives . The objective of the study was identifying occupational burnout among nurses. Material and methods . The questionnaire was responded by 408 professionally active male and female nurses, working in the territory of the West Pomeranian Voivodeship. In the evaluation of occupational burnout the standardized Maslach Burnout Inventory (MBI was applied. Results . Mean values of the level of occupational burnout for the study group amounted to 39.3 ± 30.9 with regard to emotional exhaustion, 30.64 ± 27.89 with respect to the depersonalization subscale and 66.26 ± 27.94 – the lowered level of job satisfaction. Conclusions . 1. The studied nursing personnel showed symptoms of occupational burnout in all dimensions of the syndrome, i.e. high levels of emotional exhaustion and depersonalization as well as low job satisfaction. 2. Individuals with higher education scored lower on the emotional exhaustion scale. 3. Emotional exhaustion is influenced by workplace and position.

  4. Occupational burnout among nursing personel

    Directory of Open Access Journals (Sweden)

    Sylwia Wieder-Huszla

    2016-02-01

    Full Text Available Background. Occupational stress and the related burnout syndrome is undoubtedly one of the most important challenges for public health. Objectives . The objective of the study was identifying occupational burnout among nurses. Material and methods . The questionnaire was responded by 408 professionally active male and female nurses, working in the territory of the West Pomeranian Voivodeship. In the evaluation of occupational burnout the standardized Maslach Burnout Inventory (MBI was applied. Results . Mean values of the level of occupational burnout for the study group amounted to 39.3 ± 30.9 with regard to emotional exhaustion, 30.64 ± 27.89 with respect to the depersonalization subscale and 66.26 ± 27.94 – the lowered level of job satisfaction. Conclusions . 1. The studied nursing personnel showed symptoms of occupational burnout in all dimensions of the syndrome, i.e. high levels of emotional exhaustion and depersonalization as well as low job satisfaction. 2. Individuals with higher education scored lower on the emotional exhaustion scale. 3. Emotional exhaustion is influenced by workplace and position.

  5. Burnout syndrome among dental students.

    Science.gov (United States)

    Campos, Juliana Alvares Duarte Bonini; Jordani, Paula Cristina; Zucoloto, Miriane Lucindo; Bonafé, Fernanda Salloume Sampaio; Maroco, João

    2012-03-01

    The burnout syndrome is characterized by professional exhaustion and has been reported in college students. The aim of this study was to estimate the prevalence of Burnout Syndrome among dentistry students from a public university, and its relationship to socio-demographic characteristics. All students (n = 300) were invited to participate. We used the Maslach Burnout Inventory-Student Version (MBI-SS). We carried out an analysis of the MBI-SS' psychometric properties. Multivariate Analysis of Variance (MANOVA) was performed, followed by Analysis of Variance (ANOVA) and Tukey's post-hoc tests to compare the mean scores of burnout dimensions. Of the 235 participants, 72.8% were women and the mean age was 21.0 ± 1.8 years. The MBI-SS was reliable and valid. Of the students, 17.0% had Burnout Syndrome. There was a significant relation between Burnout Syndrome and a student's performance during the course (F = 4.433, p < 0.001), medication intake because of studies (F = 7.721, p < 0.001), and the thought of dropping the course (F = 16.168, p < 0.001). The students most affected were those with poor performance, those who took medication because of studies, and those with thoughts of dropping the course. We concluded that the prevalence of the syndrome among dentistry students was high, with a significant relation between the syndrome and a student's academic performance, use of medication because of studies, and thoughts of dropping the course.

  6. Applications of Silicon Carbide for High Temperature Electronics and Sensors

    Science.gov (United States)

    Shields, Virgil B.

    1995-01-01

    Silicon carbide (SiC) is a wide bandgap material that shows great promise in high-power and high temperature electronics applications because of its high thermal conductivity and high breakdown electrical field. The excellent physical and electronic properties of SiC allows the fabrication of devices that can operate at higher temperatures and power levels than devices produced from either silicon or GaAs. Although modern electronics depends primarily upon silicon based devices, this material is not capable of handling may special requirements. Devices which operate at high speeds, at high power levels and are to be used in extreme environments at high temperatures and high radiation levels need other materials with wider bandgaps than that of silicon. Many space and terrestrial applications also have a requirement for wide bandgap materials. SiC also has great potential for high power and frequency operation due to a high saturated drift velocity. The wide bandgap allows for unique optoelectronic applications, that include blue light emitting diodes and ultraviolet photodetectors. New areas involving gas sensing and telecommunications offer significant promise. Overall, the properties of SiC make it one of the best prospects for extending the capabilities and operational regimes of the current semiconductor device technology.

  7. Ultra-high-speed Optical Signal Processing using Silicon Photonics

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Ji, Hua; Jensen, Asger Sellerup

    on silicon photonics. In particular we use nano-engineered silicon waveguides (nanowires) [1] enabling efficient phasematched four-wave mixing (FWM), cross-phase modulation (XPM) or self-phase modulation (SPM) for ultra-high-speed optical signal processing of ultra-high bit rate serial data signals. We show......— In supercomputers, the optical inter-connects are getting closer and closer to the processing cores. Today, a single supercomputer system has as many optical links as the whole worldwide web together, and it is envisaged that future computing chips will contain multiple electronic processor cores...... with a photonic layer on top to interconnect them. For such systems, silicon is an attractive candidate enabling both electronic and photonic control. For some network scenarios, it may be beneficial to use optical on-chip packet switching, and for high data-density environments one may take advantage...

  8. High-flux solar furnace processing of silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S.; Pitts, J.R.; Landry, M.D.; Menna, P.; Bingham, C.E.; Lewandowski, A.; Ciszek, T.F. [National Renewable Energy Laboratory, Golden, CO (United States)

    1996-06-10

    We used a 10-kW, high-flux solar furnace (HFSF) to diffuse the front-surface n{sup +}-p junction and the back-surface p-p{sup +} junction of single-crystal silicon solar cells in one processing step. We found that all of these HFSF-processed cells have better conversion efficiencies than control cells of identical structures fabricated by conventional furnace diffusion methods. We also used the HFSF to crystallize a-Si:H thin films on glass, to texture crystalline silicon surfaces, to deposit gold contacts on silicon wafers, and to getter impurities from metallurgical grade silicon. HFSF processing offers several advantages over conventional furnace processing: (1) it provides a cold-wall process, which reduces contamination; (2) temperature versus time profiles can be precisely controlled; (3) wavelength, intensity, and spatial distribution of the incident solar flux can be controlled and changed rapidly; (4) a number of high-temperature processing steps can be performed simultaneously; and (5) combined quantum and thermal effects may benefit overall cell performance. We conclude that HFSF processing of silicon solar cells has the potential to improve cell efficiency, reduce cell fabrication costs, and also be an environmentally friendly manufacturing method. We have also demonstrated that the HFSF can be used to achieve solid-phase crystallization of a-Si:H at very high speed

  9. High Density Through Silicon Via (TSV)

    CERN Document Server

    Rimskog, Magnus

    2008-01-01

    The Through Silicon Via (TSV) process developed by Silex provides down to 30 micrometers pitch for through wafer connections in up to 600 micrometers thick substrates. Integrated with MEMS designs it enables significantly reduced die size and true "Wafer Level Packaging" - features that are particularly important in consumer market applications. The TSV technology also enables integration of advanced interconnect functions in optical MEMS, sensors and microfluidic devices. In addition the Via technology opens for very interesting possibilities considering integration with CMOS processing. With several companies using the process already today, qualified volume manufacturing in place and a line-up of potential users, the process is becoming a standard in the MEMS industry. We provide a introduction to the via formation process and also present some on the novel solutions made available by the technology.

  10. High deposition rate nanocrystalline silicon with enhanced homogeneity

    NARCIS (Netherlands)

    Verkerk, A.; Rath, J.K.; Schropp, R.E.I.

    2010-01-01

    High rate growth of hydrogenated nanocrystalline silicon (nc-Si:H) brings additional challenges for the homogeneity in the growth direction, since the start-up effects affect a larger portion of the film, and the very high degree of depletion increases the influence of back diffusion from the inacti

  11. The Contribution of Work Characteristics, Home Characteristics and Gender to Burnout in Medical Residents

    Science.gov (United States)

    Verweij, Hanne; van der Heijden, Frank M. M. A.; van Hooff, Madelon L. M.; Prins, Jelle T.; Lagro-Janssen, Antoine L. M.; van Ravesteijn, Hiske; Speckens, Anne E. M.

    2017-01-01

    Burnout is highly prevalent in medical residents. In order to prevent or reduce burnout in medical residents, we should gain a better understanding of contributing and protective factors of burnout. Therefore we examined the associations of job demands and resources, home demands and resources, and work-home interferences with burnout in male and…

  12. Silicon photonics for high-performance interconnection networks

    Science.gov (United States)

    Biberman, Aleksandr

    2011-12-01

    We assert in the course of this work that silicon photonics has the potential to be a key disruptive technology in computing and communication industries. The enduring pursuit of performance gains in computing, combined with stringent power constraints, has fostered the ever-growing computational parallelism associated with chip multiprocessors, memory systems, high-performance computing systems, and data centers. Sustaining these parallelism growths introduces unique challenges for on- and off-chip communications, shifting the focus toward novel and fundamentally different communication approaches. This work showcases that chip-scale photonic interconnection networks, enabled by high-performance silicon photonic devices, enable unprecedented bandwidth scalability with reduced power consumption. We demonstrate that the silicon photonic platforms have already produced all the high-performance photonic devices required to realize these types of networks. Through extensive empirical characterization in much of this work, we demonstrate such feasibility of waveguides, modulators, switches, and photodetectors. We also demonstrate systems that simultaneously combine many functionalities to achieve more complex building blocks. Furthermore, we leverage the unique properties of available silicon photonic materials to create novel silicon photonic devices, subsystems, network topologies, and architectures to enable unprecedented performance of these photonic interconnection networks and computing systems. We show that the advantages of photonic interconnection networks extend far beyond the chip, offering advanced communication environments for memory systems, high-performance computing systems, and data centers. Furthermore, we explore the immense potential of all-optical functionalities implemented using parametric processing in the silicon platform, demonstrating unique methods that have the ability to revolutionize computation and communication. Silicon photonics

  13. Modern applications of high energy ion beams: From "single-event burnout" to human eye cancer treatment

    Science.gov (United States)

    Homeyer, H.; Mahnke, H.-E.

    1996-12-01

    Energetic ion beams, originally the domain of nuclear physics, become increasingly important tools in many other fields of research and development. The choice of ion species and ion energy allows an enormously wide variation of the penetration depth and of the amount of the electronic stopping power. These features are utilized to modify or damage materials and living tissues in a specific way. Materials modification with energetic ion beams is one of the central aims of research and development at the ion beam laboratory, ISL-Berlin, a center for ion-beam applications at the Hahn-Meitner-Institut Berlin. In particular, energetic protons will be used for eye cancer treatment. Selected topics such as the "single-event burnout" of high power diodes and the eye cancer therapy setup will be presented in detail.

  14. A New Approach to Identify High Burnout Medical Staffs by Kernel K-Means Cluster Analysis in a Regional Teaching Hospital in Taiwan

    Directory of Open Access Journals (Sweden)

    Yii-Ching Lee PhD

    2016-11-01

    Full Text Available This study uses kernel k-means cluster analysis to identify medical staffs with high burnout. The data collected in October to November 2014 are from the emotional exhaustion dimension of the Chinese version of Safety Attitudes Questionnaire in a regional teaching hospital in Taiwan. The number of effective questionnaires including the entire staffs such as physicians, nurses, technicians, pharmacists, medical administrators, and respiratory therapists is 680. The results show that 8 clusters are generated by kernel k-means method. Employees in clusters 1, 4, and 5 are relatively in good conditions, whereas employees in clusters 2, 3, 6, 7, and 8 need to be closely monitored from time to time because they have relatively higher degree of burnout. When employees with higher degree of burnout are identified, the hospital management can take actions to improve the resilience, reduce the potential medical errors, and, eventually, enhance the patient safety. This study also suggests that the hospital management needs to keep track of medical staffs’ fatigue conditions and provide timely assistance for burnout recovery through employee assistance programs, mindfulness-based stress reduction programs, positivity currency buildup, and forming appreciative inquiry groups.

  15. High Efficiency, Low Cost Solar Cells Manufactured Using 'Silicon Ink' on Thin Crystalline Silicon Wafers

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, H.

    2011-03-01

    Reported are the development and demonstration of a 17% efficient 25mm x 25mm crystalline Silicon solar cell and a 16% efficient 125mm x 125mm crystalline Silicon solar cell, both produced by Ink-jet printing Silicon Ink on a thin crystalline Silicon wafer. To achieve these objectives, processing approaches were developed to print the Silicon Ink in a predetermined pattern to form a high efficiency selective emitter, remove the solvents in the Silicon Ink and fuse the deposited particle Silicon films. Additionally, standard solar cell manufacturing equipment with slightly modified processes were used to complete the fabrication of the Silicon Ink high efficiency solar cells. Also reported are the development and demonstration of a 18.5% efficient 125mm x 125mm monocrystalline Silicon cell, and a 17% efficient 125mm x 125mm multicrystalline Silicon cell, by utilizing high throughput Ink-jet and screen printing technologies. To achieve these objectives, Innovalight developed new high throughput processing tools to print and fuse both p and n type particle Silicon Inks in a predetermined pat-tern applied either on the front or the back of the cell. Additionally, a customized Ink-jet and screen printing systems, coupled with customized substrate handling solution, customized printing algorithms, and a customized ink drying process, in combination with a purchased turn-key line, were used to complete the high efficiency solar cells. This development work delivered a process capable of high volume producing 18.5% efficient crystalline Silicon solar cells and enabled the Innovalight to commercialize its technology by the summer of 2010.

  16. Suicidal Thoughts Among Medical Residents with Burnout

    NARCIS (Netherlands)

    van der Heijden, Frank; Dillingh, Gea; Bakker, Arnold; Prins, Jelle

    2008-01-01

    Objectives: Recent research showed that medical residents have a high risk for developing burnout. The present study investigates the prevalence of burnout and its relationship with suicidal thoughts among medical residents. Methods: All Dutch medical residents (n = 5126) received a self-report ques

  17. Burnout among Prison Caseworkers and Corrections Officers

    Science.gov (United States)

    Carlson, Joseph R.; Thomas, George

    2006-01-01

    The purpose of this paper is to compare burnout between prison caseworkers and correctional officers and examine reasons for the high turnover of caseworkers. The study was conducted through surveys at a maximum/medium men's prison and at an all security level women's prison in the Midwest. By using the Maslach Burnout Inventory, it was found that…

  18. Suicidal Thoughts Among Medical Residents with Burnout

    NARCIS (Netherlands)

    van der Heijden, Frank; Dillingh, Gea; Bakker, Arnold; Prins, Jelle

    2008-01-01

    Objectives: Recent research showed that medical residents have a high risk for developing burnout. The present study investigates the prevalence of burnout and its relationship with suicidal thoughts among medical residents. Methods: All Dutch medical residents (n = 5126) received a self-report

  19. High energy density interpenetrating networks from ionic networks and silicone

    DEFF Research Database (Denmark)

    Yu, Liyun; Madsen, Frederikke Bahrt; Hvilsted, Søren

    2015-01-01

    The energy density of dielectric elastomers (DEs) is sought increased for better exploitation of the DE technology since an increased energy density means that the driving voltage for a certain strain can be lowered in actuation mode or alternatively that more energy can be harvested in generator...... mode. One way to increase the energy density is to increase dielectric permittivity of the elastomer. A novel silicone elastomer system with high dielectric permittivity was prepared through the development of interpenetrating networks from ionically assembled silicone polymers and covalently...

  20. High-Q silicon carbide photonic-crystal cavities

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jonathan Y. [Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York 14627 (United States); Lu, Xiyuan [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Lin, Qiang, E-mail: qiang.lin@rochester.edu [Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York 14627 (United States); Institute of Optics, University of Rochester, Rochester, New York 14627 (United States)

    2015-01-26

    We demonstrate one-dimensional photonic-crystal nanobeam cavities in amorphous silicon carbide. The fundamental mode exhibits intrinsic optical quality factor as high as 7.69 × 10{sup 4} with mode volume ∼0.60(λ/n){sup 3} at wavelength 1.5 μm. A corresponding Purcell factor value of ∼10{sup 4} is the highest reported to date in silicon carbide optical cavities. The device exhibits great potential for integrated nonlinear photonics and cavity nano-optomechanics.

  1. Nanocrystalline silicon prepared at high growth rate using helium dilution

    Indian Academy of Sciences (India)

    Koyel Bhattacharya; Debajyoti Das

    2008-06-01

    Growth and optimization of the nanocrystalline silicon (nc-Si : H) films have been studied by varying the electrical power applied to the helium diluted silane plasma in RF glow discharge. Wide optical gap and conducting intrinsic nanocrystalline silicon network of controlled crystalline volume fraction and oriented crystallographic lattice planes have been obtained at a reasonably high growth rate from helium diluted silane plasma, without using hydrogen. Improving crystallinity in the network comprising ∼ 10 nm Si-nanocrystallites and contributing optical gap widening, conductivity ascending and that obtained during simultaneous escalation of the deposition rate, promises significant technological impact.

  2. Investigations into NOx emissions and burnout for coals with high ash content in a bench scale test facility

    Energy Technology Data Exchange (ETDEWEB)

    Greul, U.; Kluger, F.; Peter, G.; Spliethoff, H.; Hein, K.R.G. [University of Stuttgart, Stuttgart (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen

    2000-07-01

    At the Stuttgart University's Institute of Process Engineering and Power Plant Technology (IVD) investigations of in-furnace DeNOx technologies with regard to their NOx reduction efficiency are carried out using an electrically heated bench-scale test facility to evaluate the effect of different process parameters independently. The DeNOx technologies of air and fuel staging have been demonstrated to be effective control techniques to reduce NOx from stationary sources. For a wide range of brown and hard coals from Europe, South Africa and Australia test runs with air-staged combustion have been carried out. The ash content of the hard coals used was in the range between 8 and 28%. The investigated parameters were temperature (1000-1300{degree}C), stoichiometry (1.25-0.55), and residence time (1-6 s) in the fuel rich primary zone. With increasing temperatures and residence times in fuel-rich conditions in air-staged combustion NOx emissions below 300 mg/m{sup 3} can be achieved even with hard coals. For a few brown coals NOx values lower than 100 mg/m{sup 3} are possible. Dependent on the coal rank individual parameters are more important than others. For low and medium volatile hard coals the increasing of the residence time is more effective than higher temperature or lower air ratios in the primary zone. However, with high volatile hard coal or brown coal as primary fuel the influence of temperature and stoichiometry in the primary zone plays a key role for NOx reduction effectiveness. The burnout led to restrictions in large scale applications for air-staged combustion especially with hard coals as primary fuel. Investigations at different primary air ratios and temperatures show the effect of these parameters on the burnout values along the course of combustion. 7 refs., 14 figs., 2 tabs.

  3. High power terahertz induced carrier multiplication in Silicon

    DEFF Research Database (Denmark)

    Tarekegne, Abebe Tilahun; Pedersen, Pernille Klarskov; Iwaszczuk, Krzysztof;

    2015-01-01

    The application of an intense THz field results a nonlinear transmission in high resistivity silicon. Upon increasing field strength, the transmission falls from 70% to 62% due to carrier generation through THz-induced impact ionization and subsequent absorption of the THz field by free electrons....

  4. Super soft silicone elastomers with high dielectric permittivity

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Yu, Liyun; Hvilsted, Søren;

    2015-01-01

    Dielectric elastomers (DEs) have many favourable properties. The obstacle of high driving voltages, however, limits the commercial viability of the technology at present. Driving voltage can be lowered by decreasing the Young’s modulus and increasing the dielectric permittivity of silicone elasto...

  5. High-field EPR spectroscopy of thermal donors in silicon

    DEFF Research Database (Denmark)

    Dirksen, R.; Rasmussen, F.B.; Gregorkiewicz, T.

    1997-01-01

    Thermal donors generated in p-type boron-doped Czochralski-grown silicon by a 450 degrees C heat treatment have been studied by high-field magnetic resonance spectroscopy. In the experiments conducted at a microwave frequency of 140 GHz and in a magnetic field of approximately 5 T four individual...

  6. Job satisfaction and burnout among paediatric nurses.

    Science.gov (United States)

    Akman, Ozlem; Ozturk, Candan; Bektas, Murat; Ayar, Dijle; Armstrong, Merry A

    2016-10-01

    This study aims to determine factors of job satisfaction and burnout levels of paediatric nurses. A total of 165 nurses working in paediatric clinics completed the Minnesota job satisfaction scale and the Maslach burnout scale. Average scores of the emotional exhaustion and depersonalisation score were low, while personal accomplishment scores were high. A high level of job satisfaction, being married, increased age and a decreased number of assigned patients were significantly associated with a low level of burnout. Paediatric nurses experience burnout at significant levels. The most important variable that affected job satisfaction was income. The results of the study could guide development of strategies that might prevent or alleviate burnout of paediatric nurses. © 2016 John Wiley & Sons Ltd.

  7. Nurses and burnout syndrome

    Directory of Open Access Journals (Sweden)

    Zarema Obradović

    2013-04-01

    Full Text Available Introduction: The work of nurses is human. They help people in protection against diseases. Nurses are the largest group of health workers and all problems that appear in the health system are first recognized among them. Burnout syndrome appears among nurses very frequently. We present the leading factors for burnout among nurses in RMC „Dr Safet Mujic“ in Mostar, Bosnia and Herzegovina.Methods: It is a cross sectional descriptive study. We used an anonymous questionnaire with 20 questions. Our sample was random with 30% of all nurses which were working in this Medical Center in January-February 2012.Results: In our study 77.9% nurses work in the hospital. 52% have over 16 years of work experience. 34.6% of examinees are satisfi ed with interpersonal relationships, 31.7 % are satisfi ed with relationships with the superior. Motivation for work have 51% of examinees, a big number comes unwilling on work.For 83.7% overtime work is the reason for dissatisfaction 71.2% examinees think that they can't make progress on work. A high percentage of examinees doesn't think about problems related to work outside working hours, a good sleep have 38.5% and 56.7% wakes up tired. Many of examinees are not satisfiedwith workplace, and 58.7% would like to change it.Conclusion: Nurses employed in RMC „Dr Safet Mujic“ Mostar are exposed to many factors during work which can cause the burnout syndrome. It is necessary to expand the study on a larger group of nurses and to implement the measures for reducing risks of burnout syndrome.

  8. Burnout syndrome prevalence in physiotherapists.

    Science.gov (United States)

    González-Sánchez, Blanca; López-Arza, María Victoria González; Montanero-Fernández, Jesús; Varela-Donoso, Enrique; Rodríguez-Mansilla, Juan; Mingote-Adán, José Carlos

    2017-04-01

    To evaluate burnout syndrome in its three aspects, jointly as well as independently, in physiotherapists from the Extremadura region (Spain). Analytic descriptive epidemiological transversal trial in primary care and institutional practice, with physiotherapists practicing in Extremadura who met the inclusion criteria, after having signed an informed consent form. Emotional exhaustion, depersonalization and low professional accomplishment were the outcomes measured. Physiotherapists from Extremadura show a 65.23 point level of burnout syndrome, according to the Maslach Burnout Inventory questionnaire. Therefore, they are positioned in the middle of the rating scale for the syndrome, and very near to the high level at starting score of 66 points. Physiotherapists in Extremadura present moderate scores for the three dimensions of burnout syndrome, namely, emotional exhaustion, depersonalization and low professional accomplishment. For this reason, they are in the moderate level of the syndrome and very near to the high level, which starts at a score of 66 points. No relation between burnout syndrome and age has been found in our study.

  9. Burnout among physicians and nursing staff working in the emergency hospital of Tanta University, Egypt.

    Science.gov (United States)

    Abdo, S A M; El-Sallamy, R M; El-Sherbiny, A A M; Kabbash, I A

    2016-03-15

    Little is known about professional burnout among health-care workers in Egypt. The current study aimed to reveal the extent of burnout among physicians and nursing staff working in the emergency hospital of Tanta University and to identify some of its determinants. A cross-sectional study was carried out on all physicians (n = 266) and a systematic random sample of nurses (n = 284). Burnout was assessed using the Maslach Burnout Inventory and its subscales. Most of the participants (66.0%)had a moderate level of burnout and 24.9% of them had high burnout. Multivariate analysis of variables affecting burnout showed that age, sex, frequency of exposure to work-related violence, years of experience, work burden, supervision and work activities were significant predictors of burnout among the respondents. The authors recommend health education interventions during pre-employment training programmes for prevention of burnout syndrome and periodic screening for early detection and management of burnout.

  10. High Resolution Silicon Deformable Mirrors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal describes a plan to build a prototype small stroke, high precision deformable mirror suitable for space-based operation in systems for high-resolution...

  11. Silicon-graphene conductive photodetector with ultra-high responsivity

    Science.gov (United States)

    Liu, Jingjing; Yin, Yanlong; Yu, Longhai; Shi, Yaocheng; Liang, Di; Dai, Daoxin

    2017-01-01

    Graphene is attractive for realizing optoelectronic devices, including photodetectors because of the unique advantages. It can easily co-work with other semiconductors to form a Schottky junction, in which the photo-carrier generated by light absorption in the semiconductor might be transported to the graphene layer efficiently by the build-in field. It changes the graphene conduction greatly and provides the possibility of realizing a graphene-based conductive-mode photodetector. Here we design and demonstrate a silicon-graphene conductive photodetector with improved responsivity and response speed. An electrical-circuit model is established and the graphene-sheet pattern is designed optimally for maximizing the responsivity. The fabricated silicon-graphene conductive photodetector shows a responsivity of up to ~105 A/W at room temperature (27 °C) and the response time is as short as ~30 μs. The temperature dependence of the silicon-graphene conductive photodetector is studied for the first time. It is shown that the silicon-graphene conductive photodetector has ultra-high responsivity when operating at low temperature, which provides the possibility to detect extremely weak optical power. For example, the device can detect an input optical power as low as 6.2 pW with the responsivity as high as 2.4 × 107 A/W when operating at −25 °C in our experiment. PMID:28106084

  12. Silicon-graphene conductive photodetector with ultra-high responsivity

    Science.gov (United States)

    Liu, Jingjing; Yin, Yanlong; Yu, Longhai; Shi, Yaocheng; Liang, Di; Dai, Daoxin

    2017-01-01

    Graphene is attractive for realizing optoelectronic devices, including photodetectors because of the unique advantages. It can easily co-work with other semiconductors to form a Schottky junction, in which the photo-carrier generated by light absorption in the semiconductor might be transported to the graphene layer efficiently by the build-in field. It changes the graphene conduction greatly and provides the possibility of realizing a graphene-based conductive-mode photodetector. Here we design and demonstrate a silicon-graphene conductive photodetector with improved responsivity and response speed. An electrical-circuit model is established and the graphene-sheet pattern is designed optimally for maximizing the responsivity. The fabricated silicon-graphene conductive photodetector shows a responsivity of up to ~105 A/W at room temperature (27 °C) and the response time is as short as ~30 μs. The temperature dependence of the silicon-graphene conductive photodetector is studied for the first time. It is shown that the silicon-graphene conductive photodetector has ultra-high responsivity when operating at low temperature, which provides the possibility to detect extremely weak optical power. For example, the device can detect an input optical power as low as 6.2 pW with the responsivity as high as 2.4 × 107 A/W when operating at ‑25 °C in our experiment.

  13. Silicon solar cells with high open-circuit voltage

    Science.gov (United States)

    Minnucci, J. A.; Matthei, K. W.; Kirkpatrick, A. R.; Mccrosky, A.

    1980-01-01

    Open-circuit voltages as high as 0.645 V (AM0-25 C) have been obtained by a new process developed for low-resistivity silicon. The method utilizes high-dose phosphorus implantation, followed by furnace annealing and simultaneous oxide growth to form high-efficiency, shallow junctions. The effect of the thermally grown oxide is a reduction of surface recombination velocity; the oxide also acts as a moderately efficient AR coating. Boron doped silicon with resistivities from 0.1 to 0.3 ohm-cm has been processed according to this sequence; results show highest open-circuit voltage is attained with 0.1-ohm-cm starting material. The effects of bandgap narrowing, caused by high doping concentrations in the junction, were also investigated by implanting phosphorus over a wide range of dose levels.

  14. Ohmic Contacts for High Temperature Integrated Circuits in Silicon Carbide

    OpenAIRE

    2014-01-01

    In electrical devices and integrated circuits, ohmic contacts are necessary and a prerequisite for the current transport over the metal-semiconductor junctions. At the same time, a desired property of the ohmic contacts is to not add resistance or in other way disturb the performance. For high temperature electronics, the material demands are high regarding functionality and stability at elevated working temperatures, during and after temperature cycling and during long time of use.  Silicon ...

  15. Silicon photodiodes with high photoconductive gain at room temperature.

    Science.gov (United States)

    Li, X; Carey, J E; Sickler, J W; Pralle, M U; Palsule, C; Vineis, C J

    2012-02-27

    Silicon photodiodes with high photoconductive gain are demonstrated. The photodiodes are fabricated in a complementary metal-oxide-semiconductor (CMOS)-compatible process. The typical room temperature responsivity at 940 nm is >20 A/W and the dark current density is ≈ 100 nA/cm2 at 5 V reverse bias, yielding a detectivity of ≈ 10(14) Jones. These photodiodes are good candidates for applications that require high detection sensitivity and low bias operation.

  16. High Resolution Silicon Deformable Mirrors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal we describe a plan to build a deformable mirror suitable for space-based operation in systems for high-resolution imaging. The prototype DM will be...

  17. Critical Size for the Particle Burn-out of Solid Carbon and/or Boron as the High-Energy Density Fuel

    OpenAIRE

    2013-01-01

    It is intended to demonstrate an existence of the critical size for the particle burn-out, exposed directly to oxidizers at high temperatures under which oxide vaporization can be facilitated, with the solid carbon taken as an example, under recognition that particles considered are too small to support a gas-phase envelop-flame even at elevated temperatures. After describing the temporal variations of the particle temperature and size, use has been made of the asymptotics to derive the gover...

  18. High-efficiency silicon heterojunction solar cells: Status and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    De Wolf, S.; Geissbuehler, J.; Loper, P.; Martin de Nicholas, S.; Seif, J.; Tomasi, A.; Ballif, C.

    2015-05-11

    Silicon heterojunction technology (HJT) uses silicon thin-film deposition techniques to fabricate photovoltaic devices from mono-crystalline silicon wafers (c-Si). This enables energy-conversion efficiencies above 21 %, also at industrial-production level. In this presentation we review the present status of this technology and point out recent trends. We first discuss how the properties of thin hydrogenated amorphous silicon (a-Si:H) films can be exploited to fabricate passivating contacts, which is the key to high- efficiency HJT solar cells. Such contacts enable very high operating voltages, approaching the theoretical limits, and yield small temperature coefficients. With this approach, an increasing number of groups are reporting devices with conversion efficiencies well over 20 % on both-sides contacted n-type cells, Panasonic leading the field with 24.7 %. Exciting results have also been obtained on p-type wafers. Despite these high voltages, important efficiency gains can still be made in fill factor and optical design. This requires improved understanding of carrier transport across device interfaces and reduced parasitic absorption in HJT solar cells. For the latter, several strategies can be followed: Short-wavelength losses can be reduced by replacing the front a-Si:H films with wider-bandgap window layers, such as silicon alloys or even metal oxides. Long- wavelength losses are mitigated by introducing new high-mobility TCO’s such as hydrogenated indium oxide, and also by designing new rear reflectors. Optical shadow losses caused by the front metallization grid are significantly reduced by replacing printed silver electrodes with fine-line plated copper contacts, leading also to possible cost advantages. The ultimate approach to minimize optical losses is the implementation of back-contacted architectures, which are completely devoid of grid shadow losses and parasitic absorption in the front layers can be minimized irrespective of electrical

  19. High-efficiency silicon heterojunction solar cells: Status and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    De Wolf, S.

    2015-04-27

    Silicon heterojunction technology (HJT) uses silicon thin-film deposition techniques to fabricate photovoltaic devices from mono-crystalline silicon wafers (c-Si). This enables energy-conversion efficiencies above 21 %, also at industrial-production level. In this presentation we review the present status of this technology and point out recent trends. We first discuss how the properties of thin hydrogenated amorphous silicon (a-Si:H) films can be exploited to fabricate passivating contacts, which is the key to high- efficiency HJT solar cells. Such contacts enable very high operating voltages, approaching the theoretical limits, and yield small temperature coefficients. With this approach, an increasing number of groups are reporting devices with conversion efficiencies well over 20 % on n-type wafers, Panasonic leading the field with 24.7 %. Exciting results have also been obtained on p-type wafers. Despite these high voltages, important efficiency gains can still be made in fill factor and optical design. This requires improved understanding of carrier transport across device interfaces and reduced parasitic absorption in HJT solar cells. For the latter, several strategies can be followed: Short- wavelength losses can be reduced by replacing the front a-Si:H films with wider-bandgap window layers, such as silicon alloys or even metal oxides. Long-wavelength losses are mitigated by introducing new high-mobility TCO’s such as hydrogenated indium oxide, and also by designing new rear reflectors. Optical shadow losses caused by the front metalisation grid are significantly reduced by replacing printed silver electrodes with fine-line plated copper contacts, leading also to possible cost advantages. The ultimate approach to minimize optical losses is the implementation of back-contacted architectures, which are completely devoid of grid shadow losses and parasitic absorption in the front layers can be minimized irrespective of electrical transport requirements. The

  20. [Personality traits, psychological adjustment, and burnout syndrome in nursing staff].

    Science.gov (United States)

    Bencomo, Juan; Paz, Cristina; Liebster, Elena

    2004-06-01

    The nursing staff is prone to develop Burnout because of the work environment and the stressful situations that develop among patients and their families. Burnout syndrome it's a persistent negative mental state, work related and present in non pathologic populations. Burnout has been associated to personality traits but the findings are too heterogeneous and do not allow plausible generalizations. To identify the relation between Burnout, Personality Traits and Psychological Adjustment, questionnaires were applied to 117 subjects, all members of the nursing staff from a University Hospital in Maracaibo, Venezuela. Traits in Burnout subjects were: sensibility to criticism, lack of confidence, poor social capacity and low Psychological Adjustment. The non-Burnout subjects presented traits of optimism, reality in the way they viewed events, proper social abilities and high Psychological Adjustment. Burnout Syndrome is not a personality type and the traits associated with this syndrome seems to be associated with Psychological Adjustment.

  1. Validity of the Maslach Burnout Inventory for family practice physicians.

    Science.gov (United States)

    Rafferty, J P; Lemkau, J P; Purdy, R R; Rudisill, J R

    1986-05-01

    This study assesses the utility of Maslach's concept of burnout for family practice physicians. Maslach Burnout Inventory (MBI) subscale correlations for the 67 residents in this sample are compared with Maslach's normative sample. The residents scored in the moderate to high range on the MBI subscales. MBI interscale correlations were similar to the pattern reported by Maslach. Significant correlations between job satisfaction and five of the six MBI subscales suggest that the construct of burnout has considerable psychological import for these physicians. The validity of the emotional exhaustion subscale is demonstrated by significant correlations with self-assessed burnout, job satisfaction, and faculty assessments of resident burnout. Independent observers were most sensitive to residents' emotional exhaustion and less likely to assess accurately the less visible aspects of burnout related to depersonalization and lack of achievement, which suggests the usefulness of multiple measures for assessing the burnout phenomenon.

  2. Continuing medical education and burnout among Danish GPs

    DEFF Research Database (Denmark)

    Brøndt, Anders; Sokolowski, Ineta; Olesen, Frede

    2008-01-01

    BACKGROUND: There has been minimal research into continuing medical education (CME) and its association with burnout among GPs. AIM: The aim of this study was to investigate the association between participating in CME and experiencing burnout in a sample of Danish GPs. DESIGN OF STUDY: Cross......-sectional questionnaire study. SETTING: All 458 active GPs in 2004, in the County of Aarhus, Denmark were invited to participate. METHOD: Data on CME activities were obtained for all GPs and linked to burnout which was measured using the Maslach Burnout Inventory - Human Services Survey. The relationship between CME...... activity and burnout was calculated as prevalence ratios (PR) in a generalised linear model. RESULTS: In total, 379 (83.5%) GPs returned the questionnaire. The prevalence of burnout was about 25%, and almost 3% suffered from 'high burnout'. A total of 344 (92.0%) GPs were members of a CME group...

  3. Occupational Burnout among Librarians.

    Science.gov (United States)

    Haack, Mary; And Others

    1984-01-01

    Outlines stages of occupational burnout (enthusiasm, stagnation, frustration, apathy) and begins empirical assessment of burnout syndrome among librarians and other information professionals. Results of pilot survey conducted at one-day conference on reference service using two measures (Staff Burnout Scale for Health Professionals, projective…

  4. High Performance Electronics on Flexible Silicon

    KAUST Repository

    Sevilla, Galo T.

    2016-09-01

    Over the last few years, flexible electronic systems have gained increased attention from researchers around the world because of their potential to create new applications such as flexible displays, flexible energy harvesters, artificial skin, and health monitoring systems that cannot be integrated with conventional wafer based complementary metal oxide semiconductor processes. Most of the current efforts to create flexible high performance devices are based on the use of organic semiconductors. However, inherent material\\'s limitations make them unsuitable for big data processing and high speed communications. The objective of my doctoral dissertation is to develop integration processes that allow the transformation of rigid high performance electronics into flexible ones while maintaining their performance and cost. In this work, two different techniques to transform inorganic complementary metal-oxide-semiconductor electronics into flexible ones have been developed using industry compatible processes. Furthermore, these techniques were used to realize flexible discrete devices and circuits which include metal-oxide-semiconductor field-effect-transistors, the first demonstration of flexible Fin-field-effect-transistors, and metal-oxide-semiconductors-based circuits. Finally, this thesis presents a new technique to package, integrate, and interconnect flexible high performance electronics using low cost additive manufacturing techniques such as 3D printing and inkjet printing. This thesis contains in depth studies on electrical, mechanical, and thermal properties of the fabricated devices.

  5. Development of high-thermal-conductivity silicon nitride ceramics

    Directory of Open Access Journals (Sweden)

    You Zhou

    2015-09-01

    Full Text Available Silicon nitride (Si3N4 with high thermal conductivity has emerged as one of the most promising substrate materials for the next-generation power devices. This paper gives an overview on recent developments in preparing high-thermal-conductivity Si3N4 by a sintering of reaction-bonded silicon nitride (SRBSN method. Due to the reduction of lattice oxygen content, the SRBSN ceramics could attain substantially higher thermal conductivities than the Si3N4 ceramics prepared by the conventional gas-pressure sintering of silicon nitride (SSN method. Thermal conductivity could further be improved through increasing the β/α phase ratio during nitridation and enhancing grain growth during post-sintering. Studies on fracture resistance behaviors of the SRBSN ceramics revealed that they possessed high fracture toughness and exhibited obvious R-curve behaviors. Using the SRBSN method, a Si3N4 with a record-high thermal conductivity of 177 Wm−1K−1 and a fracture toughness of 11.2 MPa m1/2 was developed. Studies on the influences of two typical metallic impurity elements, Fe and Al, on thermal conductivities of the SRBSN ceramics revealed that the tolerable content limits for the two impurities were different. While 1 wt% of impurity Fe hardly degraded thermal conductivity, only 0.01 wt% of Al caused large decrease in thermal conductivity.

  6. High-power thulium lasers on a silicon photonics platform.

    Science.gov (United States)

    Li, Nanxi; Purnawirman, P; Su, Zhan; Salih Magden, E; Callahan, Patrick T; Shtyrkova, Katia; Xin, Ming; Ruocco, Alfonso; Baiocco, Christopher; Ippen, Erich P; Kärtner, Franz X; Bradley, Jonathan D B; Vermeulen, Diedrik; Watts, Michael R

    2017-03-15

    Mid-infrared laser sources are of great interest for various applications, including light detection and ranging, spectroscopy, communication, trace-gas detection, and medical sensing. Silicon photonics is a promising platform that enables these applications to be integrated on a single chip with low cost and compact size. Silicon-based high-power lasers have been demonstrated at 1.55 μm wavelength, while in the 2 μm region, to the best of our knowledge, high-power, high-efficiency, and monolithic light sources have been minimally investigated. In this Letter, we report on high-power CMOS-compatible thulium-doped distributed feedback and distributed Bragg reflector lasers with single-mode output powers up to 267 and 387 mW, and slope efficiencies of 14% and 23%, respectively. More than 70 dB side-mode suppression ratio is achieved for both lasers. This work extends the applicability of silicon photonic microsystems in the 2 μm region.

  7. Silicon Sensors for Trackers at High-Luminosity Environment

    CERN Document Server

    Peltola, Timo

    2015-01-01

    The planned upgrade of the LHC accelerator at CERN, namely the high luminosity (HL) phase of the LHC (HL-LHC foreseen for 2023), will result in a more intense radiation environment than the present tracking system was designed for. The required upgrade of the all-silicon central trackers at the ALICE, ATLAS, CMS and LHCb experiments will include higher granularity and radiation hard sensors. The radiation hardness of the new sensors must be roughly an order of magnitude higher than the one of LHC detectors. To address this, a massive R&D program is underway within the CERN RD50 collaboration "Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders" to develop silicon sensors with sufficient radiation tolerance. Research topics include the improvement of the intrinsic radiation tolerance of the sensor material and novel detector designs with benefits like reduced trapping probability (thinned and 3D sensors), maximized sensitive area (active edge sensors) and enhanced charge ...

  8. High-power thermoelectric generators based on nanostructured silicon

    Science.gov (United States)

    Pennelli, G.; Macucci, M.

    2016-05-01

    The low thermal conductivity of silicon nanowires and nanostructures opens interesting opportunities for energy harvesting through the direct, high-efficiency, conversion of waste heat into electrical power. We present solutions for the fabrication and interconnection of a high number of suspended silicon nanostructures, within CMOS compatible top-down processes. Mechanical stability and thermoelectric properties of these devices will be analysed by means of finite element simulations, and opportunities for practical applications will be discussed. It will be shown that, despite the reduced dimensions needed for a strong suppression of thermal conductivity, a considerable amount of electrical power can be delivered to the load as a result of the presence of many interconnected devices on the same chip.

  9. Crystalline silicon solar cells with high resistivity emitter

    Science.gov (United States)

    Panek, P.; Drabczyk, K.; Zięba, P.

    2009-06-01

    The paper presents a part of research targeted at the modification of crystalline silicon solar cell production using screen-printing technology. The proposed process is based on diffusion from POCl3 resulting in emitter with a sheet resistance on the level of 70 Ω/□ and then, shaped by high temperature passivation treatment. The study was focused on a shallow emitter of high resistivity and on its influence on output electrical parameters of a solar cell. Secondary ion mass spectrometry (SIMS) has been employed for appropriate distinguishing the total donor doped profile. The solar cell parameters were characterized by current-voltage characteristics and spectral response (SR) methods. Some aspects playing a role in suitable manufacturing process were discussed. The situation in a photovoltaic industry with emphasis on silicon supply and current prices of solar cells, modules and photovoltaic (PV) systems are described. The economic and quantitative estimation of the PV world market is shortly discussed.

  10. Heavy doping effects in high efficiency silicon solar cells

    Science.gov (United States)

    Lindholm, F. A.; Neugroschel, A.

    1986-01-01

    The temperature dependence of the emitter saturation current for bipolar devices was studied by varying the surface recombination velocity at the emitter surface. From this dependence, the value was derived for bandgap narrowing that is in better agreement with other determinations that were obtained from the temperature dependence measure on devices with ohmic contacts. Results of the first direct measurement of the minority-carrier transit time in a transparent heavily doped emitter layer were reported. The value was obtained by a high-frequency conductance method recently developed and used for doped Si. Experimental evidence is presented for significantly greater charge storage in highly excited silicon near room temperature than conventional theory would predict. These data are compared with various data for delta E sub G in heavily doped silicon.

  11. Refinement of Eutectic Silicon Phase of Aluminum A356 Alloy Using High-Intensity Ultrasonic Vibration

    Energy Technology Data Exchange (ETDEWEB)

    Jian, Xiaogang [ORNL; Han, Qingyou [ORNL

    2006-01-01

    The eutectic silicon in A356 alloy can be refined and modified using either chemical, quench, or superheating modification. We observed, for the first time, that the eutectic silicon can also be significantly refined using high-intensity ultrasonic vibration. Rosette-like eutectic silicon is formed during solidification of specimen treated with high-intensity ultrasonic vibration.

  12. Silicon-Light: a European FP7 Project Aiming at High Efficiency Thin Film Silicon Solar Cells on Foil

    DEFF Research Database (Denmark)

    Soppe, W.; Haug, F.-J.; Couty, P.

    2011-01-01

    Silicon-Light is a European FP7 project, which started January 1st, 2010 and aims at development of low cost, high-efficiency thin film silicon solar cells on foil. Three main routes are explored to achieve these goals: a) advanced light trapping by implementing nanotexturization through UV Nano...... Imprinting Lithography (UV-NIL); b) growth of crack-free silicon absorber layers on highly textured substrates; c) development of new TCOs which should combine the best properties of presently available materials like ITO and AZO. The paper presents the midterm status of the project results, showing model...

  13. Mesoporous Silicon-Based Anodes for High Capacity, High Performance Li-ion Batteries Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new high capacity anode composite based on mesoporous silicon is proposed. By virtue of a structure that resembles a pseudo one-dimensional phase, the active...

  14. Mesoporous Silicon-Based Anodes for High Capacity, High Performance Li-ion Batteries Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new high capacity anode composite based on mesoporous silicon is proposed. By virtue of a structure that resembles a pseudo one-dimensional phase, the active anode...

  15. Valley-engineered ultra-thin silicon for high-performance junctionless transistors

    Science.gov (United States)

    Kim, Seung-Yoon; Choi, Sung-Yool; Hwang, Wan Sik; Cho, Byung Jin

    2016-07-01

    Extremely thin silicon show good mechanical flexibility because of their 2-D like structure and enhanced performance by the quantum confinement effect. In this paper, we demonstrate a junctionless FET which reveals a room temperature quantum confinement effect (RTQCE) achieved by a valley-engineering of the silicon. The strain-induced band splitting and a quantum confinement effect induced from ultra-thin-body silicon are the two main mechanisms for valley engineering. These were obtained from the extremely well-controlled silicon surface roughness and high tensile strain in silicon, thereupon demonstrating a device mobility increase of ~500% in a 2.5 nm thick silicon channel device.

  16. National Survey of Burnout among US General Surgery Residents

    Science.gov (United States)

    Elmore, Leisha C; Jeffe, Donna B; Jin, Linda; Awad, Michael M; Turnbull, Isaiah R

    2017-01-01

    Background Burnout is a complex syndrome of emotional distress that can disproportionately affect individuals who work in healthcare professions. Study Design For a national survey of burnout in US general surgery residents, we asked all Accreditation Council for Graduate Medical Education-accredited general surgery program directors to email their general surgery residents an invitation to complete an anonymous, online survey. Burnout was assessed with the Maslach Burnout Inventory; total scores for Emotional Exhaustion (EE), Depersonalization (DP), and Personal Accomplishment (PA) subscales were calculated. Burnout was defined as having a score in the highest tertile for EE or DP or lowest tertile for PA. Chi-square tests and one-way analyses of variance were used to test associations between burnout tertiles for each subscale and various resident and training-program characteristics as appropriate. Results From April–December, 2014, 665 residents actively engaged in clinical training had data for analysis; 69% met the criterion for burnout on at least one subscale. Higher burnout on each subscale was reported by residents planning private practice compared with academic careers. A greater proportion of women than men reported burnout on EE and PA. Higher burnout on EE and DP was associated with greater work hours per week. Having a structured mentoring program was associated with lower burnout on each subscale. Conclusions The high rates of burnout among general surgery residents are concerning given the potential impact of burnout on the quality of patient care. Efforts to identify at-risk populations and to design targeted interventions to mitigate burnout in surgical trainees are warranted. PMID:27238875

  17. High aspect ratio channels in glass and porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Liang, H.D. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Nanoscience and Nanotechnology Initiative (NNI), National University of Singapore, Singapore 117411 (Singapore); Dang, Z.Y. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Wu, J.F. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583 (Singapore); Kan, J.A. van; Qureshi, S. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Ynsa, M.D.; Torres-Costa, V. [Department of Applied Physics, Universidad Autónoma de Madrid, Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Centro de Micro-Análisis de Materiales (CMAM), Universidad Autónoma de Madrid, Campus de Cantoblanco Edif. 22, Faraday 3, E-28049 Madrid (Spain); Maira, A. [Department of Applied Physics, Universidad Autónoma de Madrid, Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Venkatesan, T.V. [Nanoscience and Nanotechnology Initiative (NNI), National University of Singapore, Singapore 117411 (Singapore); Breese, M.B.H., E-mail: phymbhb@nus.edu.sg [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore)

    2017-03-01

    We have developed a micromachining process to produce high-aspect-ratio channels and holes in glass and porous silicon. Our process utilizes MeV proton beam irradiation of silicon using direct writing with a focused beam, followed by electrochemical etching. To increase throughput we have also developed another process for large area ion irradiation based on a radiation-resistant gold surface mask, allowing many square inches to be patterned. We present a study of the achievable channel width, depth and period and sidewall verticality for a range of channels which can be over 100 μm deep or 100 nm wide with aspect ratios up to 80. This process overcomes the difficulty of machining glass on a micro- and nanometer scale which has limited many areas of applications in different fields such as microelectronics and microfluidics.

  18. The lattice parameter of highly pure silicon single crystals

    Science.gov (United States)

    Becker, P.; Scyfried, P.; Siegert, H.

    1982-08-01

    From crystal to crystal comparison, the d 220 lattice spacing in PERFX and WASO silicon crystals used in the only two existing absolute measurements have been found to be equal within ±2×10-7 d 220. This demonstrates that generic variabilities of the two crystals account only for a small part of the 1.8×10-6 d 220 difference in the two absolute measurements. In a new series of 336 single measurements, our d 220 value reported recently has been confirmed within ±2×10-8 d 220. From these results we derive the following lattice parameter for highly pure silicon single crystals: a 0=(543 102.018±0.034) fm (at 22.5°C, in vacuum).

  19. Silicon Photomultipliers in High Energy and Space Applications

    CERN Document Server

    Berra, Alessandro; Vallazza, Erik

    In recent years Silicon Photomultipliers (SiPMs) have been proposed as a new type of readout system for scintillating detectors in many experiments. SiPMs consist of a matrix of parallel-connected silicon micro-pixels, which are independent photon counters working in limited Geiger mode with very high gain. The goal of this thesis work is to describe the use of SiPMs as a readout system for plastic scintillators, both for tracking and calorimetry purposes. Different prototypes of scintillating bar tracker and shashlik calorimeters have been tested at CERN on the PS and SPS extracted beamlines. All the tests have been performed in the framework of the FACTOR (Fiber Apparatus for Calorimetry and Tracking with Optoelectronic Read-out) collaboration, a three year R&D project started in 2007 and funded by the Italian Institute of Nuclear Physics (INFN).

  20. High aspect ratio channels in glass and porous silicon

    Science.gov (United States)

    Liang, H. D.; Dang, Z. Y.; Wu, J. F.; van Kan, J. A.; Qureshi, S.; Ynsa, M. D.; Torres-Costa, V.; Maira, A.; Venkatesan, T. V.; Breese, M. B. H.

    2017-03-01

    We have developed a micromachining process to produce high-aspect-ratio channels and holes in glass and porous silicon. Our process utilizes MeV proton beam irradiation of silicon using direct writing with a focused beam, followed by electrochemical etching. To increase throughput we have also developed another process for large area ion irradiation based on a radiation-resistant gold surface mask, allowing many square inches to be patterned. We present a study of the achievable channel width, depth and period and sidewall verticality for a range of channels which can be over 100 μm deep or 100 nm wide with aspect ratios up to 80. This process overcomes the difficulty of machining glass on a micro- and nanometer scale which has limited many areas of applications in different fields such as microelectronics and microfluidics.

  1. Characterization of high density through silicon vias with spectral reflectometry.

    Science.gov (United States)

    Ku, Yi-Sha; Huang, Kuo Cheng; Hsu, Weite

    2011-03-28

    Measurement and control is an important step for production-worthy through silicon vias etch. We demonstrate the use and enhancement of an existing wafer metrology tool, spectral reflectometer by implementing novel theoretical model and measurement algorithm for high density through-silicon via (HDTSV) inspection. It is capable of measuring depth and depth variations of array vias by Discrete Fourier Transform (DFT) analysis in one shot measurement. Surface roughness of via bottom can also be extracted by scattering model fitting. Our non-destructive solution can measure TSV profile diameters as small as 5 μm and aspect ratios greater than 13:1. The measurement precision is in the range of 0.02 μm. Metrology results from actual 3D interconnect processing wafers are presented.

  2. High thermal conductivity of a hydrogenated amorphous silicon film.

    Science.gov (United States)

    Liu, Xiao; Feldman, J L; Cahill, D G; Crandall, R S; Bernstein, N; Photiadis, D M; Mehl, M J; Papaconstantopoulos, D A

    2009-01-23

    We measured the thermal conductivity kappa of an 80 microm thick hydrogenated amorphous silicon film prepared by hot-wire chemical-vapor deposition with the 3omega (80-300 K) and the time-domain thermo-reflectance (300 K) methods. The kappa is higher than any of the previous temperature dependent measurements and shows a strong phonon mean free path dependence. We also applied a Kubo based theory using a tight-binding method on three 1000 atom continuous random network models. The theory gives higher kappa for more ordered models, but not high enough to explain our results, even after extrapolating to lower frequencies with a Boltzmann approach. Our results show that this material is more ordered than any amorphous silicon previously studied.

  3. High current gain silicon-based spin transistor

    CERN Document Server

    Dennis, C L; Ensell, G J; Gregg, J F; Thompson, S M

    2003-01-01

    A silicon-based spin transistor of novel operating principle has been demonstrated in which the current gain at room temperature is 1.4 (n-type) and 0.97 (p-type). This high current gain was obtained from a hybrid metal/semiconductor analogue to the bipolar junction transistor which functions by tunnel-injecting carriers from a ferromagnetic emitter into a diffusion driven silicon base and then tunnel-collecting them via a ferromagnetic collector. The switching of the magnetic state of the collector ferromagnet controls the collector efficiency and the current gain. Furthermore, the magnetocurrent, which is determined to be 98% (140%) for p-type (n-type) in -110 Oe, is attributable to the spin-polarized base diffusion current.

  4. Particle detectors made of high-resistivity Czochralski silicon

    CERN Document Server

    Härkönen, J; Ivanov, A; Li, Z; Luukka, Panja; Pirojenko, A; Riihimaki, I; Tuominen, E; Tuovinen, E; Verbitskaya, E; Virtanen, A

    2005-01-01

    We have processed pin-diodes and strip detectors on n- and p-type high-resistivity silicon wafers grown by magnetic Czochralski method. The Czochralski silicon (Cz-Si) wafers manufactured by Okmetic Oyj have nominal resistivity of 900 Omega cm and 1.9 kOmega cm for n- and p-type, respectively. The oxygen concentration in these substrates is slightly less than typically in wafers used for integrated circuit fabrication. This is optimal for semiconductor fabrication as well as for radiation hardness. The radiation hardness of devices has been investigated with several irradiation campaigns including low- and high-energy protons, neutrons, gamma-rays, lithium ions and electrons. Cz-Si was found to be more radiation hard than standard Float Zone silicon (Fz-Si) or oxygenated Fz-Si. When irradiated with protons, the full depletion voltage in Cz-Si has not exceeded its initial value of 300 V even after the fluence of 5 multiplied by 10**1**4 cm**-**2 1-MeV eq. n cm **-**2 that equals more than 30 years operation of...

  5. High frequency guided wave propagation in monocrystalline silicon wafers

    Science.gov (United States)

    Pizzolato, Marco; Masserey, Bernard; Robyr, Jean-Luc; Fromme, Paul

    2017-04-01

    Monocrystalline silicon wafers are widely used in the photovoltaic industry for solar panels with high conversion efficiency. The cutting process can introduce micro-cracks in the thin wafers and lead to varying thickness. High frequency guided ultrasonic waves are considered for the structural monitoring of the wafers. The anisotropy of the monocrystalline silicon leads to variations of the wave characteristics, depending on the propagation direction relative to the crystal orientation. Full three-dimensional Finite Element simulations of the guided wave propagation were conducted to visualize and quantify these effects for a line source. The phase velocity (slowness) and skew angle of the two fundamental Lamb wave modes (first anti-symmetric mode A0 and first symmetric mode S0) for varying propagation directions relative to the crystal orientation were measured experimentally. Selective mode excitation was achieved using a contact piezoelectric transducer with a custom-made wedge and holder to achieve a controlled contact pressure. The out-of-plane component of the guided wave propagation was measured using a noncontact laser interferometer. Good agreement was found with the simulation results and theoretical predictions based on nominal material properties of the silicon wafer.

  6. Silicon sensors for trackers at high-luminosity environment

    Science.gov (United States)

    Peltola, Timo

    2015-10-01

    The planned upgrade of the LHC accelerator at CERN, namely the high luminosity (HL) phase of the LHC (HL-LHC foreseen for 2023), will result in a more intense radiation environment than the present tracking system that was designed for. The required upgrade of the all-silicon central trackers at the ALICE, ATLAS, CMS and LHCb experiments will include higher granularity and radiation hard sensors. The radiation hardness of the new sensors must be roughly an order of magnitude higher than in the current LHC detectors. To address this, a massive R&D program is underway within the CERN RD50 Collaboration "Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders" to develop silicon sensors with sufficient radiation tolerance. Research topics include the improvement of the intrinsic radiation tolerance of the sensor material and novel detector designs with benefits like reduced trapping probability (thinned and 3D sensors), maximized sensitive area (active edge sensors) and enhanced charge carrier generation (sensors with intrinsic gain). A review of the recent results from both measurements and TCAD simulations of several detector technologies and silicon materials at radiation levels expected for HL-LHC will be presented.

  7. Burnout among healthcare professionals.

    Science.gov (United States)

    Wood, Ben D; Killion, Jeffrey B

    2007-01-01

    *From many accounts healthcare professionals are at increased risk for professional burnout. Professional burnout is generally described as prolonged stress that impairs one's ability to perform his or her job in demanding situations. *Precursors to professional burnout include, but are not limited to, employee workload, chronic fatigue, compassion fatigue, balance between family and career, sickness absence, and loss of confidence. *Administrators must watch for early signs of professional burnout to improve retention and promote employee morale. To reduce professional burnout, administrators must implement strategies to reduce burnout while also promoting productivity. *When professional burnout occurs, management must consider each employee's generational differences. All generations have differing values, beliefs, and opinions that influence his or her work ethic in regard to employee productivity.

  8. Teacher Burnout: A Laughing Matter

    Science.gov (United States)

    McKenzie, Kemberly Elaine

    2009-01-01

    This study employed a quantitative research method and examined the relationship among teacher burnout, job-related stress and humor coping styles in 306 high school teachers from the south suburbs of Chicago, Illinois. In particular, this study sought to determine if a relationship existed among the three variables by examining if teacher burnout…

  9. Teacher Burnout in Agricultural Education.

    Science.gov (United States)

    Croom, D. Barry

    2003-01-01

    Results of the Maslach Burnout Inventory completed by 164 secondary agriculture teachers revealed moderate levels of emotional exhaustion, low levels of depersonalization in relationships, and a high degree of personal accomplishment. Gender, degree, contract length, preservice versus lateral entry method, school/department size, and community…

  10. Pulsed Nd:YAG laser cladding of high silicon content coating on low silicon steel

    Institute of Scientific and Technical Information of China (English)

    Danyang Dong; Changsheng Liu; Bin Zhang; Jun Miao

    2007-01-01

    A pulsed Nd:YAG (yttrium aluminum garnet) laser-based technique was employed to clad low silicon steel with preplaced Si and Fe mixed powders for high Si content. The surface morphology, microstructural evolution, phase composition, and Si distribution,within the obtained cladding coatings, were characterized by optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), with associated energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The microhardness was also measured along the depth direction of the specimens. A crack- and pore-free cladding coating through excellent metallurgical bonding with the substrate was successfully prepared on low silicon steel by means of optimized single-track and multi-track laser cladding. The phases of the coating are α-Fe, γ-Fe, and FeSi. The high microhardness of the lasercladding zone is considered as an increase in Si content and as the refined microstructure produced by the laser treatment. The Si contents of the cladding coatings were about 5.8wt% in the single-track cladding and 6.5wt% in the multi-track cladding, respectively.

  11. Burnout and risk factors for cardiovascular diseases.

    Science.gov (United States)

    Melamed, S; Kushnir, T; Shirom, A

    1992-01-01

    The burnout syndrome denotes a constellation of physical fatigue, emotional exhaustion, and cognitive weariness resulting from chronic stress. Although it overlaps considerably with chronic fatigue as defined in internal medicine, its links with physical illness have not been systematically investigated. This exploratory study, conducted among 104 male workers free from cardiovascular disease (CVD), tested the association between burnout and two of its common concomitants--tension and listlessness--and cardiovascular risk factors. After ruling out five possible confounders (age, relative weight, smoking, alcohol use, and sports activity), the authors found that scores on burnout plus tension (tense-burnout) were associated with somatic complaints, cholesterol, glucose, triglycerides, uric acid, and, marginally, with ECG abnormalities. Workers scoring high on tense-burnout also had a significantly higher low density lipoprotein (LDL) level. Conversely, scores on burnout plus listlessness were significantly associated with glucose and negatively with diastolic blood pressure. The findings warrant further study of burnout as a predictor of cardiovascular morbidity and mortality.

  12. Silicon-Light: a European FP7 Project Aiming at High Efficiency Thin Film Silicon Solar Cells on Foil

    DEFF Research Database (Denmark)

    Soppe, W.; Haug, F.-J.; Couty, P.

    2011-01-01

    Silicon-Light is a European FP7 project, which started January 1st, 2010 and aims at development of low cost, high-efficiency thin film silicon solar cells on foil. Three main routes are explored to achieve these goals: a) advanced light trapping by implementing nanotexturization through UV Nano...... calculations of ideal nanotextures for light trapping in thin film silicon solar cells; the fabrication of masters and the replication and roll-to-roll fabrication of these nanotextures. Further, results on ITO variants with improved work function are presented. Finally, the status of cell fabrication on foils...

  13. Association of adaptive and maladaptive narcissism with personal burnout: findings from a cross-sectional study

    Science.gov (United States)

    VON KÄNEL, Roland; HERR, Raphael Manfred; VAN VIANEN, Annelies Elizabeth Maria; SCHMIDT, Burkhard

    2017-01-01

    Burnout is associated with poor mental and physical functioning and high costs for societies. Personality attributes may critically increase the risk of personal burnout. We specifically examined whether narcissism associates with personal burnout in a working population. We studied n=1,461 employees (mean age 41.3 ± 9.4 yr, 52% men) drawn from a random sample of a pharmaceutical company in Germany. All participants completed the personal burnout subscale of the Copenhagen Burnout Inventory and the Narcissistic Personality Inventory to assess maladaptive (entitlement/exploitativeness) and adaptive (leadership/authority) narcissism. In linear regression analysis, when mutually adjusting for the maladaptive and adaptive narcissism scales, higher adaptive narcissism was associated with lower burnout scores (ß=−0.04, pnarcissism was associated with higher burnout scores (ß=0.04, pnarcissism was associated with increased levels of burnout symptoms, adaptive narcissism was associated with fewer burnout symptoms. PMID:28123136

  14. Silicon Carbide Diodes Performance Characterization at High Temperatures

    Science.gov (United States)

    Lebron-Velilla, Ramon C.; Schwarze, Gene E.; Gardner, Brent G.; Adams, Jerry

    2004-01-01

    NASA Glenn Research center's Electrical Systems Development branch is working to demonstrate and test the advantages of Silicon Carbide (SiC) devices in actual power electronics applications. The first step in this pursuit is to obtain commercially available SiC Schottky diodes and to individually test them under both static and dynamic conditions, and then compare them with current state of the art silicon Schottky and ultra fast p-n diodes of similar voltage and current ratings. This presentation covers the results of electrical tests performed at NASA Glenn. Steady state forward and reverse current-volt (I-V) curves were generated for each device to compare performance and to measure their forward voltage drop at rated current, as well as the reverse leakage current at rated voltage. In addition, the devices were individually connected as freewheeling diodes in a Buck (step down) DC to DC converter to test their reverse recovery characteristics and compare their transient performance in a typical converter application. Both static and transient characterization tests were performed at temperatures ranging from 25 C to 300 C, in order to test and demonstrate the advantages of SiC over Silicon at high temperatures.

  15. Brain inspired high performance electronics on flexible silicon

    KAUST Repository

    Sevilla, Galo T.

    2014-06-01

    Brain\\'s stunning speed, energy efficiency and massive parallelism makes it the role model for upcoming high performance computation systems. Although human brain components are a million times slower than state of the art silicon industry components [1], they can perform 1016 operations per second while consuming less power than an electrical light bulb. In order to perform the same amount of computation with today\\'s most advanced computers, the output of an entire power station would be needed. In that sense, to obtain brain like computation, ultra-fast devices with ultra-low power consumption will have to be integrated in extremely reduced areas, achievable only if brain folded structure is mimicked. Therefore, to allow brain-inspired computation, flexible and transparent platform will be needed to achieve foldable structures and their integration on asymmetric surfaces. In this work, we show a new method to fabricate 3D and planar FET architectures in flexible and semitransparent silicon fabric without comprising performance and maintaining cost/yield advantage offered by silicon-based electronics.

  16. Diamond and silicon pixel detectors in high radiation environments

    Energy Technology Data Exchange (ETDEWEB)

    Tsung, Jieh-Wen

    2012-10-15

    Diamond pixel detector is a promising candidate for tracking of collider experiments because of the good radiation tolerance of diamond. The diamond pixel detector must withstand the radiation damage from 10{sup 16} particles per cm{sup 2}, which is the expected total fluence in High Luminosity Large Hadron Collider. The performance of diamond and silicon pixel detectors are evaluated in this research in terms of the signal-to-noise ratio (SNR). Single-crystal diamond pixel detectors with the most recent readout chip ATLAS FE-I4 are produced and characterized. Based on the results of the measurement, the SNR of diamond pixel detector is evaluated as a function of radiation fluence, and compared to that of planar-silicon ones. The deterioration of signal due to radiation damage is formulated using the mean free path of charge carriers in the sensor. The noise from the pixel readout circuit is simulated and calculated with leakage current and input capacitance to the amplifier as important parameters. The measured SNR shows good agreement with the calculated and simulated results, proving that the performance of diamond pixel detectors can exceed the silicon ones if the particle fluence is more than 10{sup 15} particles per cm{sup 2}.

  17. Low heart rate variability in patients with clinical burnout.

    Science.gov (United States)

    Lennartsson, Anna-Karin; Jonsdottir, Ingibjörg; Sjörs, Anna

    2016-12-01

    Several studies have shown that acute psychosocial stress and chronic psychosocial stress reduce heart rate variability (HRV). It is likely that individuals suffering from burnout have reduced HRV, as a consequence of the long-term stress exposure. This study investigated HRV in 54 patients with clinical burnout (40 women and 14 men) and in 55 individuals reporting low burnout scores (healthy; 24 women and 31 men) and 52 individuals reporting high burnout scores (non-clinical burnout; 33 women and 19 men). The participants underwent a 300s ECG recording in the supine position. Standard deviation of normal R-R intervals (SDNN) and the root mean square of successive normal interval differences (RMSSD) were derived from time domain HRV analysis. Frequency domain HRV measures; total power (TP), low frequency power (LF), high frequency power (HF), and LF/HF ratio were calculated. All HRV measures, except LF/HF ratio, were lower in the clinical burnout patients compared to both the non-clinical burnout group and the healthy group. The difference was larger between the patients and the healthy group than between the patients and the non-clinical burnout group. HRV did not differ significantly between the non-clinical burnout group and the healthy group. Low HRV in burnout patients may constitute one of the links to associated adverse health, since low HRV reflects low parasympathetic activity - and accordingly low anabolic/regenerative activity.

  18. For Caregivers: Coping with Burnout

    Science.gov (United States)

    ... Your Community Advocate Get Involved Donate Coping With Burnout Being a caregiver of someone with ALS is ... Solutions in Dealing with Burnout Common Causes of Burnout Perfectionism: A perfectionist continually focuses on what needs ...

  19. Feeding of liquid silicon for high performance multicrystalline silicon with increased ingot height and homogenized resistivity

    Science.gov (United States)

    Krenckel, Patricia; Riepe, Stephan; Schindler, Florian; Strauch, Theresa

    2017-04-01

    Feeding of liquid silicon during the directional solidification process is a promising opportunity for cost reduction by increased throughput and improved material homogeneity due to constant resistivity over ingot height. In this work, a liquid feeding apparatus was developed for an industrial type directional solidification furnace. One n-type G2 sized High Performance multicrystalline ingot with liquid feeding of additional 14 kg of undoped silicon feedstock was crystallized. The resistivity was kept within a range of ±0.1 Ω cm of the target resistivity during the feeding sequence. A smaller mean grain area growth was observed during feeding, whereas the area fraction of recombination active dislocation structures was as low as in a reference ingot. Increased interstitial oxygen and substitutional carbon concentrations were measured for the ingot with liquid feeding. The measured mean bulk lifetime of 190 μs for passivated wafers in the feeding sequence can probably be increased by further pre-melting crucible improvements. For this laboratory experiment, energy reductions of 2% per wafer and time savings of 16% per wafer were realized.

  20. Burnout in the intensive care unit professionals

    Directory of Open Access Journals (Sweden)

    Kalpalatha K Guntupalli

    2014-01-01

    Full Text Available Background: Professional burnout has been widely explored in health care. We conducted this study in our hospital intensive care unit (ICU in United States to explore the burnout among nurses and respiratory therapists (RT. Materials and Methods: A survey consisting of two parts was used to assess burnout. Part 1 addressed the demographic information and work hours. Part 2 addressed the Maslach Burnout Inventory-Human Service Survey. Results: The analysis included 213 total subjects; Nurses 151 (71% and RT 62 (29%. On the emotional exhaustion (EE scale, 54% scored "Moderate" to "High" and 40% scored "Moderate" to "High" on the depersonalization (DP scale. Notably 40.6% scored "Low" on personal accomplishment (PA scale. Conclusion: High level of EE, DP and lower PAs were seen among two groups of health care providers in the ICUs.

  1. Therapy of the burnout syndrome [Therapie des Burnout-Syndroms

    Directory of Open Access Journals (Sweden)

    Korczak, Dieter

    2012-06-01

    Full Text Available [english] The prevalence, diagnostics and therapy of the burnout syndrome are increasingly discussed in the public. The unclear definition and diagnics of the burnout syndrome are scientifically criticized. There are several therapies with unclear evidence for the treatment of burnout in existence.The health technology assessment (HTA report deals with the question of usage and efficacy of different burnout therapies.For the years 2006 to 2011, a systematic literature research was done in 31 electronic databases (e.g. EMBASE, MEDLINE, PsycINFO. Important inclusion criteria are burnout, therapeutic intervention and treatment outcome.17 studies meet the inclusion criteria and are regarded for the HTA report. The studies are very heterogeneous (sample size, type of intervention, measuring method, level of evidence. Due to their study design (e.g. four reviews, eight randomized controlled trials the studies have a comparable high evidence: three times 1A, five times 1B, one time 2A, two times 2B and six times 4. 13 of the 17 studies are dealing with the efficacy of psychotherapy and psychosocial interventions for the reduction of burnout (partly in combination with other techniques. Cognitive behaviour therapy leads to the improvement of emotional exhaustion in the majority of the studies. The evidence is inconsistent for the efficacy of stress management and music therapy. Two studies regarding the efficacy of Qigong therapy do not deliver a distinct result. One study proves the efficacy of roots of Rhodiola rosea (evidence level 1B. Physical therapy is only in one study separately examined and does not show a better result than standard therapy.Despite the number of studies with high evidence the results for the efficacy of burnout therapies are preliminary and do have only limited reach. The authors of the studies complain about the low number of skilled studies for the therapy of burnout. Furthermore, they point to the insufficient evaluation of

  2. High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

    Science.gov (United States)

    Bozak, Karin E.; Pinero, Luis R.; Scheidegger, Robert J.; Aulisio, Michael V.; Gonzalez, Marcelo C.; Birchenough, Arthur G.

    2015-01-01

    A silicon carbide brassboard power processing unit has been developed by the NASA Glenn Research Center in Cleveland, Ohio. The power processing unit operates from two sources: a nominal 300 Volt high voltage input bus and a nominal 28 Volt low voltage input bus. The design of the power processing unit includes four low voltage, low power auxiliary supplies, and two parallel 7.5 kilowatt (kW) discharge power supplies that are capable of providing up to 15 kilowatts of total power at 300 to 500 Volts (V) to the thruster. Additionally, the unit contains a housekeeping supply, high voltage input filter, low voltage input filter, and master control board, such that the complete brassboard unit is capable of operating a 12.5 kilowatt Hall effect thruster. The performance of the unit was characterized under both ambient and thermal vacuum test conditions, and the results demonstrate exceptional performance with full power efficiencies exceeding 97%. The unit was also tested with a 12.5kW Hall effect thruster to verify compatibility and output filter specifications. With space-qualified silicon carbide or similar high voltage, high efficiency power devices, this would provide a design solution to address the need for high power electric propulsion systems.

  3. High performance high-κ/metal gate complementary metal oxide semiconductor circuit element on flexible silicon

    KAUST Repository

    Sevilla, Galo T.

    2016-02-29

    Thinned silicon based complementary metal oxide semiconductor(CMOS)electronics can be physically flexible. To overcome challenges of limited thinning and damaging of devices originated from back grinding process, we show sequential reactive ion etching of silicon with the assistance from soft polymeric materials to efficiently achieve thinned (40 μm) and flexible (1.5 cm bending radius) silicon based functional CMOSinverters with high-κ/metal gate transistors. Notable advances through this study shows large area of silicon thinning with pre-fabricated high performance elements with ultra-large-scale-integration density (using 90 nm node technology) and then dicing of such large and thinned (seemingly fragile) pieces into smaller pieces using excimer laser. The impact of various mechanical bending and bending cycles show undeterred high performance of flexible siliconCMOSinverters. Future work will include transfer of diced silicon chips to destination site, interconnects, and packaging to obtain fully flexible electronic systems in CMOS compatible way.

  4. Silicon sensors for trackers at high-luminosity environment

    Energy Technology Data Exchange (ETDEWEB)

    Peltola, Timo, E-mail: timo.peltola@helsinki.fi

    2015-10-01

    The planned upgrade of the LHC accelerator at CERN, namely the high luminosity (HL) phase of the LHC (HL-LHC foreseen for 2023), will result in a more intense radiation environment than the present tracking system that was designed for. The required upgrade of the all-silicon central trackers at the ALICE, ATLAS, CMS and LHCb experiments will include higher granularity and radiation hard sensors. The radiation hardness of the new sensors must be roughly an order of magnitude higher than in the current LHC detectors. To address this, a massive R&D program is underway within the CERN RD50 Collaboration “Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders” to develop silicon sensors with sufficient radiation tolerance. Research topics include the improvement of the intrinsic radiation tolerance of the sensor material and novel detector designs with benefits like reduced trapping probability (thinned and 3D sensors), maximized sensitive area (active edge sensors) and enhanced charge carrier generation (sensors with intrinsic gain). A review of the recent results from both measurements and TCAD simulations of several detector technologies and silicon materials at radiation levels expected for HL-LHC will be presented. - Highlights: • An overview of the recent results from the RD50 collaboration. • Accuracy of TCAD simulations increased by including both bulk and surface damage. • Sensors with n-electrode readout and MCz material offer higher radiation hardness. • 3D detectors are a promising choice for the extremely high fluence environments. • Detectors with an enhanced charge carrier generation under systematic investigation.

  5. [Burnout in Residential Drug- and Alcohol Treatment

    Science.gov (United States)

    Härtel, Roland; Limmer, Uwe; Schiller, Martin; Wolfersdorf, Manfred

    2003-05-01

    OBJECTIVE: The study aimed at comparing burnout in staff members at residential drug and alcohol detoxification wards with and without teamsupervision. METHOD: 4 times in a period of 18 month all staff members (n = 44) were assessed for burnout using a german version (Checkliste Burnoutmerkmale) of the Maslach Burnout Inventory (MBI, Maslach u. Jackson 1986) to asses the severity and the CBE (Checkliste Burnoutentstehungsmerkmale) for associated burnout risc-factors. RESULT: There was no statistical differences between the mean scores of the 3 different wards due to extreme SDs. The interpersonal differences among staff on the 4 occasions were remarkably. On repeated measurements the intraindividual changes were high. Higher scores were correlated with high workload (seen as frequent admissions). CONCLUSION: Work-related variables (admissions) turned out to be of more importance than supervision in times of chronic staff-shortage.

  6. High Voltage Operation of heavily irradiated silicon microstrip detectors

    CERN Document Server

    Gu, W H; Angarano, M M; Bader, A; Biggeri, U; Boemi, D; Braibant, S; Breuker, H; Bruzzi, Mara; Caner, A; Catacchini, E; Civinini, C; Creanza, D; D'Alessandro, R; Demaria, N; Eklund, C; Peisert, Anna; Feld, L; Fiore, L; Focardi, E; Fürtjes, A; Glessing, B; Hall, G; Hammerstrom, R; Dollan, Ralph; Huhtinen, M; Karimäki, V; König, S; Lenzi, M; Lübelsmeyer, K; Maggi, G; Mannelli, M; Marchioro, A; Mariotti, C; Mättig, P; McEvoy, B; Meschini, M; My, S; Pandoulas, D; Parrini, G; Pieri, M; Dollan, Ralph; Potenza, R; Raso, G; Raymond, M; Schmitt, B; Selvaggi, G; Siedling, R; Silvestris, L; Skog, K; Stefanini, G; Tempesta, P; Tricomi, A; Watts, S; Wittmer, B; De Palma, M

    1999-01-01

    We discuss the results obtained from the R&D studies, done within the CMS experiment at LHC related to the behaviour of silicon microstrip prototype detectors when they are operated at high bias voltages before and after heavy irradiation, simulating up to 10 years of LHC running conditions. We have found detectors from several manufacturesrs that are able to work at V_bias > 500 Volts before and after the irradiation procedure, maintaining an acceptable performance with S/N > 14, efficiency close to 100% and few ghost hits.

  7. High efficiency interdigitated back contact silicon solar cells

    Science.gov (United States)

    Verlinden, P.; van de Wiele, F.; Stehelin, G.; Floret, F.; David, J. P.

    Interdigitated back contact (IBC) silicon solar cells with 25.6 percent efficiency at 10 W/sq cm and 24.4 percent at 30 W/ sq cm were fabricated. The authors report on the technological process, which produces a high effective carrier lifetime in the bulk (780 microsec), and on the characterization of the cells. The front side of these cells is textured and has an efficient polka-dot floating tandem junction. IBC and point-contact (PC) cells are fabricated on the same substrate and their efficiencies are compared. The possiblity of reaching 29 percent efficiency at 300X is shown.

  8. Schoolwork engagement and burnout among Finnish high school students and young adults: profiles, progressions, and educational outcomes.

    Science.gov (United States)

    Tuominen-Soini, Heta; Salmela-Aro, Katariina

    2014-03-01

    Applying a person-centered approach, the primary aim of this study was to examine what profiles of schoolwork engagement and burnout (i.e., exhaustion, cynicism, inadequacy) can be identified in high school (N = 979) and among the same participants in young adulthood (ages ranging from 17 to 25). We also examined gender differences, group differences in academic and socioemotional functioning and long-term educational outcomes, and temporal stability in the group memberships. Latent profile analysis identified 4 groups of students in high school. Both engaged (44%) and engaged-exhausted (28%) students were engaged and doing well in school, although engaged-exhausted students were more stressed and preoccupied with possible failures. Cynical (14%) and burned-out (14%) students were less engaged, valued school less, and had lower academic achievement. Cynical students, however, were less stressed, exhausted, and depressed than burned-out students. Six years later, engaged students were more likely than predicted by chance to attend university. In young adulthood, 4 similar groups were identified. Configural frequency analysis indicated that it was typical for engaged students to stay in the engaged group and for engaged-exhausted students to move into a more disengaged group. The results on broadband stability from adolescence to young adulthood showed that 60% of the youth manifested stable engaged and 7% stable disengaged patterns, whereas 16% displayed emergent engagement and 17% emergent disengagement patterns. Overall, the findings demonstrate that adolescence is not a uniform time for either school engagement and well-being or disengagement and distress.

  9. [Burnout and teamwork in primary care teams].

    Science.gov (United States)

    Vilà Falgueras, Maite; Cruzate Muñoz, Carlota; Orfila Pernas, Francesc; Creixell Sureda, Joan; González López, María Pilar; Davins Miralles, Josep

    2015-01-01

    To estimate the prevalence of burnout and the perception of teamwork in Primary Care teams from Barcelona. Multicenter cross-sectional. Primary Health Care Teams from Barcelona. Institut Català de la Salut. All permanent employees or temporary professionals of all categories from 51 teams (N=2398). A total of 879 responses (36.7%) were obtained. The Maslach Burnout Inventory questionnaire, with 3 dimensions, was sent by emotional exhaustion (AE), depersonalization (DP), and personal accomplishment (RP). Burnout is considered present when two or more dimensions scored high marks. Perception of teamwork and evaluation of leaders was evaluated using an ad hoc questionnaire. The prevalence of burnout was17.2% (two or more dimensions affected), and 46.2% had at least one of the three dimensions with a high level. A high level of AE was found in 38.2%, of DP in 23.8%, and 7.7% had low RP. Almost half (49.2%) believe that teamwork is encouraged in their workplace. Social workers overall, have a higher average of dimensions affected at a high level, followed by administrative personnel, dentists, doctors and nurses (pteamwork had more emotional exhaustion, depersonalization and higher level of burnout in general (pTeamwork and appreciating their leaders protect from burnout. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  10. Electrical properties of deuteron irradiated high resistivity silicon

    Energy Technology Data Exchange (ETDEWEB)

    Krupka, Jerzy, E-mail: krupka@imio.pw.edu.pl [Insitute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Karcz, Waldemar [H. Niewodniczański Institute of Nuclear Physics Polish Academy of Science, Cracow (Poland); Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna (Russian Federation); Avdeyev, Sergej P. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna (Russian Federation); Kamiński, Paweł; Kozłowski, Roman [Institute of Electronic Materials Technology, Wólczyńska 133, 01-919 Warsaw (Poland)

    2014-04-01

    We have investigated resistivity changes introduced on the high-resistivity p-type silicon wafer by the irradiation with deuteron beam with an energy of 4.4 GeV performed in the NUCLOTRON superconducting accelerator. Two contactless techniques were used for the measurements of resistivity changes: namely the microwave split post dielectric resonator (SPDR) technique and capacitance measurements in the frequency domain. The first technique allows resistivity measurements in the plane of the wafer, while the second one in the direction perpendicular to the wafer. The resistivity map obtained with the SPDR technique enabled us to obtain a permanent fingerprint of the accelerator beam intensity profile. It has been shown that after the irradiation, the material resistivity increased to ∼3.9 × 10{sup 5} Ω cm in the wafer region exposed to the maximum beam intensity. Complementary studies of the properties and concentrations of radiation deep-level defects were performed by the high-resolution photo-induced current transient spectroscopy (HRPITS). These studies have shown that the irradiation of the high resistivity silicon with 4.4-GeV deuterons results in the formation of several types of deep-level defects responsible for the charge compensation.

  11. [Burnout syndrome among physiotherapists].

    Science.gov (United States)

    Owczarek, Krzysztof; Wojtowicz, Stanisław; Pawłowski, Witold; Białoszewski, Dariusz

    2017-01-01

    Burnout is a syndrome of emotional exhaustion, depersonalization, and a reduced sense of personal accomplishment. Symptoms of burnout include mental and physical exhaustion, accompanied by psychosomatic disorders and emotional problems. Burnout occurs most often in people employed in occupations requiring working with people (human services) as a result of coping with stress and experience numerous failures at work. The aim of the research is the analysis of burnout among physiotherapists and demographic factors and conditions that may contribute to the burnout. 212 (137 woman and 75 man) physiotherapists completed an anonymous questionnaire to assess burnout created by Owczarek and Olczyk. The age of respondents ranged between 20 to 56 years, with work experience from several months to more than 30 years. Total score of burnout was 115,66 (SD 21,78). On the scale of attitude to work 36,82 was achieved, workload - 34,76, contact with the patient - 27,54, and an attitude towards stress - 16,54, which means that the result obtained fit in the lower zone including average results concerning the level of burnout. Women had a higher level of professional burnout than men. Respondents who reported that their working conditions are not conducive to achieving therapeutic success (quality of equipment, size of treatment rooms, treatment technologies), exhibited a higher level of burnout. The average result of the level of burnout among physiotherapists is lower than all the results obtained in other occupational groups of health care workers, lead with the same diagnostic tool. Burnout syndrome among practicing physiotherapists require further study, taking into account the type and quality of jobs, but also the level of referral among professional physiotherapists.

  12. Occupational burnout and health

    OpenAIRE

    Ahola, Kirsi

    2007-01-01

    Occupational burnout and heath Occupational burnout is assumed to be a negative consequence of chronic work stress. In this study, it was explored in the framework of occupational health psychology, which focusses on psychologically mediated processes between work and health. The objectives were to examine the overlap between burnout and ill health in relation to mental disorders, musculoskeletal disorders, and cardiovascular diseases, which are the three commonest disease groups causing...

  13. Factors associated with burnout among residents in a developing country

    Science.gov (United States)

    Zubairi, Akbar Jaleel; Noordin, Shahryar

    2016-01-01

    Introduction Recent literature has focused on burnout as a specific job related distress syndrome among physicians and residents having adverse effects on patient care. Local data on burnout is lacking. Materials & methods An online self-administered questionnaire was sent via email to all residents (325) at our institute with and a response rate of 110 (34%) was achieved. Out of these 82 residents consented and completely filled the questionnaires and were included in the analysis. The questionnaire comprised of demographic variables, the Maslach burnout inventory and occupational risk factors. Results High levels of burnout on at least one subscale were reported by 61(74.4%) residents, in 2 components by 34(41.5%) whereas an alarming 10(12.2%) residents scored high on all three subscales. Among the individual subscales emotional exhaustion was most frequent in 49(59.8%). Among the departments Radiology reported the highest levels (100%) of burnout and low levels were reported by Pediatrics (45%). There was no difference between burnout levels among junior and senior residents. Dissatisfaction with workload, length of work hours, relationship with co-workers and lack of autonomy were significantly associated with high level of burnout. Conclusion High levels of burnout are prevalent among trainee doctors in our part of the world which are comparable with international literature. Efforts to improve the work environment of residents may significantly reduce levels of burnout. PMID:26955475

  14. Highly sensitive and reproducible silicon-based surface-enhanced Raman scattering sensors for real applications.

    Science.gov (United States)

    Wang, Houyu; Jiang, Xiangxu; He, Yao

    2016-08-15

    During the past few decades, thanks to silicon nanomaterials' outstanding electronic/optical/mechanical properties, large surface-to-volume ratio, abundant surface chemistry, facile tailorability and good compatibility with modern semiconductor industry, different dimensional silicon nanostructures have been widely employed for rationally designing and fabricating high-performance surface-enhanced Raman scattering (SERS) sensors for the detection of various chemical and biological species. Among these, two-dimensional silicon nanostructures made of metal nanoparticle-modified silicon wafers and three-dimensional silicon nanostructures made of metal nanoparticle-decorated SiNW arrays are of particular interest, and have been extensively exploited as promising silicon-based SERS-active substrates for the construction of high-performance SERS sensors. With an aim to retrospect these important and exciting achievements, we herein focus on reviewing recent representative studies on silicon-based SERS sensors for sensing applications from a broad perspective and possible future direction, promoting readers' awareness of these novel powerful silicon-based SERS sensing technologies. Firstly, we summarize the two unique merits of silicon-based SERS sensors, and those are high sensitivity and good reproducibility. Next, we present recent advances of two- and three-dimensional silicon-based SERS sensors, especially for real applications. Finally, we discuss the major challenges and prospects for the development of silicon-based SERS sensors.

  15. Silicon Needles Fabricated by Highly Selective Anisotropic Dry Etching and Their Field Emission Current Characteristics

    Science.gov (United States)

    Kanechika, Masakazu; Mitsushima, Yasuichi

    2000-12-01

    A new process to fabricate a silicon needle, whose tip radius is about 5 nm and aspect ratio is about 7, was developed. The silicon needles were fabricated by highly selective anisotropic dry etching. The etching mask was oxygen precipitation, which was formed by nitrogen ion implantation and the subsequent oxidation. The process is simple enough to be integrated with complementary metal-oxide-semiconductor (CMOS) circuits. The density of the silicon needle can be controlled by adjusting the dose for nitrogen ion implantation. The position of the silicon needle can be controlled by adjusting the position for nitrogen ion implantation, because silicon needles are formed only in the nitrogen ion implantation area. Furthermore, using these silicon needles as micro emitters, a field emission diode was fabricated. The Fowler-Nordheim plot shows that the field around the tip of the silicon needles was highly enhanced.

  16. Forming high efficiency silicon solar cells using density-graded anti-reflection surfaces

    Science.gov (United States)

    Yuan, Hao-Chih; Branz, Howard M.; Page, Matthew R.

    2014-09-09

    A method (50) is provided for processing a graded-density AR silicon surface (14) to provide effective surface passivation. The method (50) includes positioning a substrate or wafer (12) with a silicon surface (14) in a reaction or processing chamber (42). The silicon surface (14) has been processed (52) to be an AR surface with a density gradient or region of black silicon. The method (50) continues with heating (54) the chamber (42) to a high temperature for both doping and surface passivation. The method (50) includes forming (58), with a dopant-containing precursor in contact with the silicon surface (14) of the substrate (12), an emitter junction (16) proximate to the silicon surface (14) by doping the substrate (12). The method (50) further includes, while the chamber is maintained at the high or raised temperature, forming (62) a passivation layer (19) on the graded-density silicon anti-reflection surface (14).

  17. Burnout in the intensive care unit professionals

    Science.gov (United States)

    Guntupalli, Kalpalatha K.; Wachtel, Sherry; Mallampalli, Antara; Surani, Salim

    2014-01-01

    Background: Professional burnout has been widely explored in health care. We conducted this study in our hospital intensive care unit (ICU) in United States to explore the burnout among nurses and respiratory therapists (RT). Materials and Methods: A survey consisting of two parts was used to assess burnout. Part 1 addressed the demographic information and work hours. Part 2 addressed the Maslach Burnout Inventory-Human Service Survey. Results: The analysis included 213 total subjects; Nurses 151 (71%) and RT 62 (29%). On the emotional exhaustion (EE) scale, 54% scored “Moderate” to “High” and 40% scored “Moderate” to “High” on the depersonalization (DP) scale. Notably 40.6% scored “Low” on personal accomplishment (PA) scale. Conclusion: High level of EE, DP and lower PAs were seen among two groups of health care providers in the ICUs. PMID:24701063

  18. High quality crystalline silicon surface passivation by combined intrinsic and n-type hydrogenated amorphous silicon

    NARCIS (Netherlands)

    Schuttauf, J.A.; van der Werf, C.H.M.; Kielen, I.M.; van Sark, W.G.J.H.M.; Rath, J.K.

    2011-01-01

    We investigate the influence of thermal annealing on the passivation quality of crystalline silicon (c-Si) surfaces by intrinsic and n-type hydrogenated amorphous silicon (a-Si:H) films. For temperatures up to 255 C, we find an increase in surface passivation quality, corresponding to a decreased da

  19. Mindful meditation: healing burnout in critical care nursing.

    Science.gov (United States)

    Davies, William Richard

    2008-01-01

    The nursing profession is experiencing a crisis in both manpower and the ability to fend off the deleterious effects of burnout. Nursing professionals face extraordinary stress in our present medical environment, and studies have frequently found moderate-to-high levels of burnout among nurses. Nurses experience burnout for a variety of reasons, some inherent to the profession and others related to our 21st-century values that have necessitated multiple breadwinners within the household. Mindful meditation represents a complementary therapy that has shown promise in the reduction of negative stress and those extraneous factors that lead to burnout. A mindful, meditative practice can be another tool with which critical care nurses can regain the control of their careers and personal lives. The purpose of this article is to describe nurse burnout, identify those factors that contribute to burnout, and offer a solution to a continuing problem for nurses.

  20. Myers Briggs Type Indicator, burnout, and satisfaction in Illinois dentists.

    Science.gov (United States)

    Baran, Ronald B

    2005-01-01

    There is conflicting research concerning satisfaction and burnout levels in dentistry. High levels of burnout can have deleterious effects on the dentist, his or her family, and patients. A random sample of Illinois general dentists was examined using the Myers Briggs Type Indicator, the Maslach Burnout Inventory, the Dentist Satisfaction Survey, and a demographic questionnaire. Areas examined were the frequency of types compared to a base population as well as the relationship of type to levels of satisfaction, burnout, and demographic items. Three of the 16 Myers Briggs types were overrepresented in this sample, while two types were underrepresented. Slightly less than half of the dentists were satisfied with their profession; 7.4% had reached significant levels of burnout and 83% perceived dentistry as being "very stressful." The personality types overrepresented in dentistry tended to have a higher level of satisfaction and a lower level of burnout compared to their cohort group.

  1. Cavity cooling of free silicon nanoparticles in high vacuum.

    Science.gov (United States)

    Asenbaum, Peter; Kuhn, Stefan; Nimmrichter, Stefan; Sezer, Ugur; Arndt, Markus

    2013-01-01

    Laser cooling has given a boost to atomic physics throughout the last 30 years, as it allows one to prepare atoms in motional states, which can only be described by quantum mechanics. Most methods rely, however, on a near-resonant and cyclic coupling between laser light and well-defined internal states, which has remained a challenge for mesoscopic particles. An external cavity may compensate for the lack of internal cycling transitions in dielectric objects and it may provide assistance in the cooling of their centre-of-mass state. Here we demonstrate cavity cooling of the transverse kinetic energy of silicon nanoparticles freely propagating in high vacuum (<10(-8) mbar). We create and launch them with longitudinal velocities down to v≤1 m s(-1) using laser-induced ablation of a pristine silicon wafer. Their interaction with the light of a high-finesse infrared cavity reduces their transverse kinetic energy by up to a factor of 30.

  2. High-flux solar furnace processing of silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S.; Pitts, J.R.; Landry, M.D.; Bingham, C.E.; Lewandowski, A.; Ciszek, T.F. [National Renewable Energy Lab., Golden, CO (United States)

    1994-12-31

    The authors used a 10-kW high-flux solar furnace (HFSF) to diffuse the front-surface n{sup +}-p junction and the back-surface p-p{sup +} junction of single-crystal silicon solar cells in one processing step. They found that all of the HFSF-processed cells have better conversion efficiencies than control cells of identical structures fabricated by conventional furnace diffusion methods. HFSF processing offers several advantages that may contribute to improved solar cell efficiency: (1) it provides a cold-wall process, which reduces contamination; (2) temperature versus time profiles can be precisely controlled; (3) wavelength, intensity, and spatial distribution of the incident solar flux can be controlled and changed rapidly; (4) a number of high-temperature processing steps can be performed simultaneously; and (5) combined quantum and thermal effects may benefit overall cell performance. The HFSF has also been successfully used to texture the surface of silicon wafers and to crystallize a-Si:H thin films on glass.

  3. Silicon-carbon interactions in high latitude watersheds

    Science.gov (United States)

    Humborg, C.; Morth, C.; Struyf, E.; Conley, D. J.

    2008-12-01

    Changes in climate and hydrology in high latitude regions could liberate large amounts of previously inactive organic carbon (OC) during a prolonging thawing period, and new studies have shown that a great deal of this organic C is remineralized as CO2 during its transport to the sea. However, OC (with its origin in atmospheric carbon) and dissolved silicate (DSi) concentrations in taiga and tundra rivers are intimately linked, and higher concentrations of weathering products are found in taiga and tundra rivers with a higher percentage of peat in their watersheds. It appears that the weathering regime of taiga and tundra watersheds is tightly linked to carbon-silicon interactions, in which carbon acts both as a weathering agent (soil CO2 from degradation of OC) and as a weathering product (DSi and bicarbonate). Whereas respiration of OC can be regarded as a positive feedback to global warming, weathering can be regarded as a negative feedback to global warming since atmospheric CO2 is converted to bicarbonate and thereby locked into the aquatic phase for geological time scales. Thus, bicarbonate export may compensate for significant amounts of exported OC thereby reducing the positive feedback to atmospheric CO2. However, the silicon-carbon interactions are not straight forward as suggested by classical inverse modelling,using the stochiometry of rock forming minerals as base, since high latitude wetlands contain a massive stock of amorphous silica (diatoms and phytoliths) buffering the actual DSi export, suggesting that the Si cycle is to a large extent biologically controlled.

  4. A microstrip silicon telescope for high performance particle tracking

    Science.gov (United States)

    Lietti, D.; Berra, A.; Prest, M.; Vallazza, E.

    2013-11-01

    Bent crystals are thin silicon/germanium devices that act as a bulk dipole magnet and thus are able to deflect relativistic charged particle beams with high efficiency (up to 98%). To study their behavior on extracted beamlines in terms of deflection capability and efficiency, a fast and high position resolution telescope is needed such as the INSULAB telescope. It consists in several modules equipped with double or single side silicon detectors readout by different ASICs. The Data Acquisition system is designed to work with pulsed beams minimizing the dead time to allow the collection of a large statistics in a short time. It is based on custom VME readout/memory boards for the data storage and 12 bit ADC custom boards for the signal digitization; the present maximum DAQ rate is 6 kHz. A detailed description of the detectors, the ASICs and the readout system together with the results obtained at the SPS H4 and PS T9 CERN beamlines in terms of spatial resolution and charge sharing are presented.

  5. High mechanical Q-factor measurements on silicon bulk samples

    Energy Technology Data Exchange (ETDEWEB)

    Nawrodt, R; Zimmer, A; Koettig, T; Schwarz, C; Heinert, D; Hudl, M; Neubert, R; Thuerk, M; Nietzsche, S; Vodel, W; Seidel, P [Friedrich-Schiller-Universitaet, Institut fuer Festkoerperphysik, Helmholtzweg 5, D-07743 Jena (Germany); Tuennermann, A [Friedrich-Schiller-Universitaet, Institut fuer Angewandte Physik, Max-Wien-Platz 1, D-07743 Jena (Germany)], E-mail: ronny.nawrodt@uni-jena.de

    2008-07-15

    Future gravitational wave detectors will be limited by different kinds of noise. Thermal noise from the coatings and the substrate material will be a serious noise contribution within the detection band of these detectors. Cooling and the use of a high mechanical Q-factor material as a substrate material will reduce the thermal noise contribution from the substrates. Silicon is one of the most interesting materials for a third generation cryogenic detector. Due to the fact that the coefficient of thermal expansion vanishes at 18 and 125 K the thermoelastic contribution to the thermal noise will disappear. We present a systematic analysis of the mechanical Q-factor at low temperatures between 5 and 300 K on bulk silicon (100) samples which are boron doped. The thickness of the cylindrical samples is varied between 6, 12, 24, and 75mm with a constant diameter of 3 inches. For the 75mm substrate a comparison between the (100) and the (111) orientation is presented. In order to obtain the mechanical Q-factor a ring-down measurement is performed. Thus, the substrate is excited to resonant vibrations by means of an electrostatic driving plate and the subsequent ring-down is recorded using a Michelson-like interferometer. The substrate itself is suspended as a pendulum by means of a tungsten wire loop. All measurements are carried out in a special cryostat which provides a temperature stability of better than 0.1K between 5 and 300K during the experiment. The influence of the suspension on the measurements is experimentally investigated and discussed. At 5.8K a highest Q-factor of 4.5 x 10{sup 8} was achieved for the 14.9 kHz mode of a silicon (100) substrate with a diameter of 3 inches and a thickness of 12 mm.

  6. [Burnout in Dutch medical students: prevalence and causes].

    Science.gov (United States)

    Conijn, Maartjie; Boersma, Henri J M V; van Rhenen, Willem

    2015-01-01

    To investigate the prevalence and causes of burnout in Dutch medical students. Questionnaire survey. All 14,570 student members of the KNMG (Royal Dutch Medical Association) were invited to fill in a digital survey. Burnout was determined with the Utrecht Burnout Scale (UBOS). Triggering and protective factors for burnout were also investigated . 2,739 medical students (18.8%) completed the survey and 14.5 per cent of all respondents met the burnout criteria. 17.8 per cent of the hospital interns who responded and 11.6 per cent of the preclinical students who responded met these criteria. Work-home interference and high levels of emotional pressure had the strongest link to burn-out, while a sufficient amount of support from family, friends and peers reduced the risk of burnout in both undergraduates and hospital interns. Our exploratory research suggests that the prevalence of burnout is high, particularly among the hospital interns who responded. The most important contributory factors are high levels of emotional pressure and work-home interference. The low percentage of respondents makes it difficult to make any statement about the prevalence and causes of burnout among all Dutch medical students.

  7. Review of silicon solar cells for high concentrations

    Science.gov (United States)

    Schwartz, R. J.

    1982-06-01

    The factors that limit the performance of high concentration silicon solar cells are reviewed. The design of a conventional high concentration cell is discussed, together with the present state of the art. Unconventional cell designs that have been proposed to overcome the limitations of the conventional design are reviewed and compared. The current status of unconventional cells is reviewed. Among the unconventional cells discussed are the interdigitated back-contact cell, the double-sided cell, the polka dot cell, and the V-groove cell. It is noted that all the designs for unconventional cells require long diffusion lengths for high efficiency operation, even though the demands in this respect are less for those cells with the optical path longer than the diffusion path.

  8. Mechanically flexible optically transparent silicon fabric with high thermal budget devices from bulk silicon (100)

    KAUST Repository

    Hussain, Muhammad Mustafa

    2013-05-30

    Today’s information age is driven by silicon based electronics. For nearly four decades semiconductor industry has perfected the fabrication process of continuingly scaled transistor – heart of modern day electronics. In future, silicon industry will be more pervasive, whose application will range from ultra-mobile computation to bio-integrated medical electronics. Emergence of flexible electronics opens up interesting opportunities to expand the horizon of electronics industry. However, silicon – industry’s darling material is rigid and brittle. Therefore, we report a generic batch fabrication process to convert nearly any silicon electronics into a flexible one without compromising its (i) performance; (ii) ultra-large-scale-integration complexity to integrate billions of transistors within small areas; (iii) state-of-the-art process compatibility, (iv) advanced materials used in modern semiconductor technology; (v) the most widely used and well-studied low-cost substrate mono-crystalline bulk silicon (100). In our process, we make trenches using anisotropic reactive ion etching (RIE) in the inactive areas (in between the devices) of a silicon substrate (after the devices have been fabricated following the regular CMOS process), followed by a dielectric based spacer formation to protect the sidewall of the trench and then performing an isotropic etch to create caves in silicon. When these caves meet with each other the top portion of the silicon with the devices is ready to be peeled off from the bottom silicon substrate. Release process does not need to use any external support. Released silicon fabric (25 μm thick) is mechanically flexible (5 mm bending radius) and the trenches make it semi-transparent (transparency of 7%). © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  9. Silicon carbide high performance optics: a cost-effective, flexible fabrication process

    Science.gov (United States)

    Casstevens, John M.; Rashed, Abuagela; Plummer, Ronald; Bray, Don; Gates, Rob L.; Lara-Curzio, Edgar; Ferber, Matt K.; Kirkland, Tim

    2001-12-01

    Silicon carbide may well be the best known material for the manufacture of high performance optical components. This material offers many advantages over glasses and metals that have historically been used in high performance optical systems. A combination of extremely high specific stiffness (E/r), high thermal conductivity and outstanding dimensional stability make silicon carbide superior overall to beryllium and low-expansion glass ceramics. A major impediment to wide use of silicon carbide in optical systems has been the cost associated with preliminary shaping and final finishing of silicon carbide. Because silicon carbide is an extremely hard and strong material, precision machining can only be done with expensive diamond tooling on very stiff high quality machine tools. Near-net-shape slip casting of silicon carbide can greatly reduce the cost of silicon carbide mirror substrates but this process still requires significant diamond grinding of the cast components. The process described here begins by machining the component from all special type of graphite. This graphite can rapidly be machined with conventional multi-axis CNC machine tools to achieve any level of complexity and lightweighting required. The graphite is then directly converted completely to silicon carbide with very small and very predictable dimensional change. After conversion to silicon carbide the optical surface is coated with very fine grain CVD silicon carbide which is easily polished to extreme smoothness. Details of the fabrication process are described and photos and performance specifications of an eight-inch elliptical demonstration mirror are provided.

  10. Pediatric nurses' grief experience, burnout and job satisfaction.

    Science.gov (United States)

    Adwan, Jehad Z

    2014-01-01

    Correlations among grief, burnout, and job satisfaction among highly satisfied pediatric nurses were examined using the Revised Grief Experience Inventory (RGEI), Maslach Burnout Inventory (MBI), and Index of Work Satisfaction (IWS). Results showed that grief had significant correlations; positive with burnout, negative with job satisfaction. RN's reported significantly higher emotional exhaustion if their primary patients died and higher guilt if patients died younger. Conclusions suggest a dynamic statistical interaction among nurses' grief, burnout, and job satisfaction representing a pathway to intention to leave their unit, organization, or nursing. Recommendations include implementation and evaluation of grief intervention and education programs.

  11. Job dissatisfaction and burnout of nurses in Hunan, China: A cross-sectional survey.

    Science.gov (United States)

    Zhou, Wenjuan; He, Guoping; Wang, Honghong; He, Ying; Yuan, Qun; Liu, Dan

    2015-12-01

    In this study, we focused on measuring levels of nurse burnout and job dissatisfaction in the daily practice of nurses in Hunan province, China, analyzed factors related to nurse burnout and job dissatisfaction, and explored the relationship between them. Previous studies have shown a high level of burnout and job dissatisfaction among nurses worldwide. A cross-sectional survey of 1100 nurses was conducted. The nurses worked at 20 hospitals in 11 cities and counties throughout China's Hunan province. Nurse burnout was measured by the Maslach Burnout Inventory. Nurse-rated job dissatisfaction was described using a four point scale, and work environment was measured using the Nursing Work Index - Practice Environment Scale. The results showed that nurses had high burnout scores and were dissatisfied with their jobs. Staffing, work environment, and work hours were all significantly associated with nurse burnout and job dissatisfaction. Adequate staffing, improved work environment, and reasonable work hours are related to decreasing nurse burnout and job dissatisfaction.

  12. Characterization of Three High Efficiency and Blue Sensitive Silicon Photomultipliers

    CERN Document Server

    Otte, Adam Nepomuk; Nguyen, Thanh; Purushotham, Dhruv

    2016-01-01

    We report about the optical and electrical characterization of three high efficiency and blue sensitive Silicon photomultipliers from FBK, Hamamatsu, and SensL. Key features of the tested devices when operated at 90% breakdown probability are peak photon detection efficiencies between 40% and 55%, temperature dependencies of gain and PDE that are less than 1%/$^{\\circ}$C, dark rates of $\\sim$50\\,kHz/mm$^{2}$ at room temperature, afterpulsing of about 2%, and direct optical crosstalk between 6% and 20%. The characteristics of all three devices impressively demonstrate how the Silicon-photomultiplier technology has improved over the past ten years. It is further demonstrated how the voltage and temperature characteristics of a number of quantities can be parameterized on the basis of physical models. The models provide a deeper understanding of the device characteristics over a wide bias and temperature range. They also serve as examples how producers could provide the characteristics of their SiPMs to users. A...

  13. Characterization of three high efficiency and blue sensitive silicon photomultipliers

    Science.gov (United States)

    Otte, Adam Nepomuk; Garcia, Distefano; Nguyen, Thanh; Purushotham, Dhruv

    2017-02-01

    We report about the optical and electrical characterization of three high efficiency and blue sensitive Silicon photomultipliers from FBK, Hamamatsu, and SensL. Key features of the tested devices when operated at 90% breakdown probability are peak photon detection efficiencies between 40% and 55%, temperature dependencies of gain and PDE that are less than 1%/°C, dark rates of ∼50 kHz/mm2 at room temperature, afterpulsing of about 2%, and direct optical crosstalk between 6% and 20%. The characteristics of all three devices impressively demonstrate how the Silicon-photomultiplier technology has improved over the past ten years. It is further demonstrated how the voltage and temperature characteristics of a number of quantities can be parameterized on the basis of physical models. The models provide a deeper understanding of the device characteristics over a wide bias and temperature range. They also serve as examples how producers could provide the characteristics of their SiPMs to users. A standardized parameterization of SiPMs would enable users to find the optimal SiPM for their application and the operating point of SiPMs without having to perform measurements thus significantly reducing design and development cycles.

  14. Silicone elastomers with high dielectric permittivity and high dielectric breakdown strength based on tunable functionalized copolymers

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Yu, Liyun; Daugaard, Anders Egede;

    2015-01-01

    High driving voltages currently limit the commercial potential of dielectric elastomers (DEs). One method used to lower driving voltage is to increase dielectric permittivity of the elastomer. A novel silicone elastomer system with high dielectric permittivity was prepared through the synthesis o...

  15. Silicone elastomers with high dielectric permittivity and high dielectric breakdown strength based on tunable functionalized copolymers

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Yu, Liyun; Daugaard, Anders Egede

    2015-01-01

    High driving voltages currently limit the commercial potential of dielectric elastomers (DEs). One method used to lower driving voltage is to increase dielectric permittivity of the elastomer. A novel silicone elastomer system with high dielectric permittivity was prepared through the synthesis o...

  16. Synthetic Strategies for High Dielectric Constant Silicone Elastomers

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt

    Dielectric electroactive polymers (DEAPs) are a new and promising transducer technology and are often referred to as ‘artificial muscles’, due to their ability to undergo large deformations when stimulated by electric fields. DEAPs consist of a soft and thin elastomeric film (an elastomer...... synthetic strategies were developed in this Ph.D. thesis, in order to create silicone elastomers with high dielectric constants and thereby higher energy densities. The work focused on maintaining important properties such as dielectric loss, electrical breakdown strength and elastic modulus....... The methodology therefore involved chemically grafting high dielectric constant chemical groups onto the elastomer network, as this would potentially provide a stable elastomer system upon continued activation of the material. The first synthetic strategy involved the synthesis of a new type of cross...

  17. The Investigation and Analysis of Job Burnout Among High School Teachers in Henan%河南省高中教师工作倦怠现状调查及影响因素研究

    Institute of Scientific and Technical Information of China (English)

    李乾锋

    2013-01-01

    The study investigate the situation of job burnout of high school teacher in Henan province,and to discuss the relationship among the core self-evaluation, organizational identification and job burnout. By the measurement of core self-evaluation questionnaire, organizational identification questionnaire and job burnout to 358 teachers of high school in Henan province.%通过对全省某次教师会议358名河南省高中教师施测核心自我评价问卷,组织认同问卷和工作倦怠问卷,对河南省高中教师工作倦怠现状进行调查,并探讨核心自我评价和组织认同对工作倦怠的影响。

  18. Depression-Burnout Overlap in Physicians

    Science.gov (United States)

    Wurm, Walter; Vogel, Katrin; Holl, Anna; Ebner, Christoph; Bayer, Dietmar; Mörkl, Sabrina; Szilagyi, Istvan-Szilard; Hotter, Erich; Kapfhammer, Hans-Peter; Hofmann, Peter

    2016-01-01

    Background Whether burnout is a distinct phenomenon rather than a type of depression and whether it is a syndrome, limited to three “core” components (emotional exhaustion, depersonalization and low personal accomplishment) are subjects of current debate. We investigated the depression-burnout overlap, and the pertinence of these three components in a large, representative sample of physicians. Methods In a cross-sectional study, all Austrian physicians were invited to answer a questionnaire that included the Major Depression Inventory (MDI), the Hamburg Burnout Inventory (HBI), as well as demographic and job-related parameters. Of the 40093 physicians who received an invitation, a total of 6351 (15.8%) participated. The data of 5897 participants were suitable for analysis. Results Of the participants, 10.3% were affected by major depression. Our study results suggest that potentially 50.7% of the participants were affected by symptoms of burnout. Compared to physicians unaffected by burnout, the odds ratio of suffering from major depression was 2.99 (95% CI 2.21–4.06) for physicians with mild, 10.14 (95% CI 7.58–13.59) for physicians with moderate, 46.84 (95% CI 35.25–62.24) for physicians with severe burnout and 92.78 (95% CI 62.96–136.74) for the 3% of participants with the highest HBI_sum (sum score of all ten HBI components). The HBI components Emotional Exhaustion, Personal Accomplishment and Detachment (representing depersonalization) tend to correlate more highly with the main symptoms of major depression (sadness, lack of interest and lack of energy) than with each other. A combination of the HBI components Emotional Exhaustion, Helplessness, Inner Void and Tedium (adj.R2 = 0.92) explained more HBI_sum variance than the three “core” components (adj.R2 = 0.85) of burnout combined. Cronbach’s alpha for Emotional Exhaustion, Helplessness, Inner Void and Tedium combined was 0.90 compared to α = 0.54 for the combination of the three

  19. Depression-Burnout Overlap in Physicians.

    Directory of Open Access Journals (Sweden)

    Walter Wurm

    Full Text Available Whether burnout is a distinct phenomenon rather than a type of depression and whether it is a syndrome, limited to three "core" components (emotional exhaustion, depersonalization and low personal accomplishment are subjects of current debate. We investigated the depression-burnout overlap, and the pertinence of these three components in a large, representative sample of physicians.In a cross-sectional study, all Austrian physicians were invited to answer a questionnaire that included the Major Depression Inventory (MDI, the Hamburg Burnout Inventory (HBI, as well as demographic and job-related parameters. Of the 40093 physicians who received an invitation, a total of 6351 (15.8% participated. The data of 5897 participants were suitable for analysis.Of the participants, 10.3% were affected by major depression. Our study results suggest that potentially 50.7% of the participants were affected by symptoms of burnout. Compared to physicians unaffected by burnout, the odds ratio of suffering from major depression was 2.99 (95% CI 2.21-4.06 for physicians with mild, 10.14 (95% CI 7.58-13.59 for physicians with moderate, 46.84 (95% CI 35.25-62.24 for physicians with severe burnout and 92.78 (95% CI 62.96-136.74 for the 3% of participants with the highest HBI_sum (sum score of all ten HBI components. The HBI components Emotional Exhaustion, Personal Accomplishment and Detachment (representing depersonalization tend to correlate more highly with the main symptoms of major depression (sadness, lack of interest and lack of energy than with each other. A combination of the HBI components Emotional Exhaustion, Helplessness, Inner Void and Tedium (adj.R2 = 0.92 explained more HBI_sum variance than the three "core" components (adj.R2 = 0.85 of burnout combined. Cronbach's alpha for Emotional Exhaustion, Helplessness, Inner Void and Tedium combined was 0.90 compared to α = 0.54 for the combination of the three "core" components.This study demonstrates the

  20. Patterned growth of high aspect ratio silicon wire arrays at moderate temperature

    Science.gov (United States)

    Morin, Christine; Kohen, David; Tileli, Vasiliki; Faucherand, Pascal; Levis, Michel; Brioude, Arnaud; Salem, Bassem; Baron, Thierry; Perraud, Simon

    2011-04-01

    High aspect ratio silicon wire arrays with excellent pattern fidelity over wafer-scale area were grown by chemical vapor deposition at moderate temperature, using a gas mixture of silane and hydrogen chloride. An innovative two-step process was developed for in situ doping of silicon wires by diborane. This process led to high p-type doping levels, up to 10 18-10 19 cm -3, without degradation of the silicon wire array pattern fidelity.

  1. Crystalline-Amorphous Core−Shell Silicon Nanowires for High Capacity and High Current Battery Electrodes

    KAUST Repository

    Cui, Li-Feng

    2009-01-14

    Silicon is an attractive alloy-type anode material for lithium ion batteries because of its highest known capacity (4200 mAh/g). However silicon\\'s large volume change upon lithium insertion and extraction, which causes pulverization and capacity fading, has limited its applications. Designing nanoscale hierarchical structures is a novel approach to address the issues associated with the large volume changes. In this letter, we introduce a core-shell design of silicon nanowires for highpower and long-life lithium battery electrodes. Silicon crystalline- amorphous core-shell nanowires were grown directly on stainless steel current collectors by a simple one-step synthesis. Amorphous Si shells instead of crystalline Si cores can be selected to be electrochemically active due to the difference of their lithiation potentials. Therefore, crystalline Si cores function as a stable mechanical support and an efficient electrical conducting pathway while amorphous shells store Li ions. We demonstrate here that these core-shell nanowires have high charge storage capacity (̃1000 mAh/g, 3 times of carbon) with ̃90% capacity retention over 100 cycles. They also show excellent electrochemical performance at high rate charging and discharging (6.8 A/g, ̃20 times of carbon at 1 h rate). © 2009 American Chemical Society.

  2. Philosophy of Music Education and the Burnout Syndrome: Female Viewpoints on a Male School World

    Science.gov (United States)

    Kertz-Welzel, Alexandra

    2009-01-01

    Burnout is a risk for many music teachers, particularly the highly successful and effective teachers. Burnout is more than a personal feeling of discomfort or fatigue. It is an attack on professional efficiency and personal integrity. Burnout is affecting male and female music teachers in different ways, because women tend to react to stress in…

  3. Relationship among Self-Efficacy, Social Support, Job Satisfaction, and Teacher-Related Burnout

    Science.gov (United States)

    Watts, Gannon J.

    2014-01-01

    Human-service professions are at high-risk for burnout including the teaching profession. Work-related burnout is a gradual process widespread among many professionals and is in response to stressful events. Some of the current research has been focused on teachers with work-related burnout. An area of limited research has been the potential…

  4. Special Education Teacher Burnout: A Synthesis of Research from 1979 to 2013

    Science.gov (United States)

    Brunsting, Nelson C.; Sreckovic, Melissa A.; Lane, Kathleen Lynne

    2014-01-01

    Teacher burnout occurs when teachers undergoing stress for long periods of time experience emotional exhaustion, depersonalization, and lack of personal accomplishment (Maslach, 2003). Outcomes associated with burnout include teacher attrition, teacher health issues, and negative student outcomes. Special educators are at high risk for burnout as…

  5. Burnout and Physical Health among Social Workers: A Three-Year Longitudinal Study

    Science.gov (United States)

    Kim, Hansung; Ji, Juye; Kao, Dennis

    2011-01-01

    The high risk of burnout in the social work profession is well established, but little is known about burnout's impact on the physical health of social workers. This article examines the relationship between burnout and physical health, using data from a longitudinal study of social workers. California-registered social workers (N = 406) were…

  6. Philosophy of Music Education and the Burnout Syndrome: Female Viewpoints on a Male School World

    Science.gov (United States)

    Kertz-Welzel, Alexandra

    2009-01-01

    Burnout is a risk for many music teachers, particularly the highly successful and effective teachers. Burnout is more than a personal feeling of discomfort or fatigue. It is an attack on professional efficiency and personal integrity. Burnout is affecting male and female music teachers in different ways, because women tend to react to stress in…

  7. Burnout and Physical Health among Social Workers: A Three-Year Longitudinal Study

    Science.gov (United States)

    Kim, Hansung; Ji, Juye; Kao, Dennis

    2011-01-01

    The high risk of burnout in the social work profession is well established, but little is known about burnout's impact on the physical health of social workers. This article examines the relationship between burnout and physical health, using data from a longitudinal study of social workers. California-registered social workers (N = 406) were…

  8. Relationship among Self-Efficacy, Social Support, Job Satisfaction, and Teacher-Related Burnout

    Science.gov (United States)

    Watts, Gannon J.

    2014-01-01

    Human-service professions are at high-risk for burnout including the teaching profession. Work-related burnout is a gradual process widespread among many professionals and is in response to stressful events. Some of the current research has been focused on teachers with work-related burnout. An area of limited research has been the potential…

  9. Work-Stress Burnout in Emergency Medical Technicians and the Use of Early Recollections.

    Science.gov (United States)

    Vettor, Susan M.; Kosinski, Frederick A., Jr.

    2000-01-01

    Numerous studies have indicated a high work-stress burnout rate of emergency medical technicians, although none have used techniques predicting work-stress burnout. Discusses early memories that are representative of emergency medical technicians who may be susceptible to burnout, and memories that may indicate an individual's resistance to…

  10. Association of adaptive and maladaptive narcissism with personal burnout: findings from a cross-sectional study.

    Science.gov (United States)

    VON Känel, Roland; Herr, Raphael Manfred; VAN Vianen, Annelies Elizabeth Maria; Schmidt, Burkhard

    2017-06-08

    Burnout is associated with poor mental and physical functioning and high costs for societies. Personality attributes may critically increase the risk of personal burnout. We specifically examined whether narcissism associates with personal burnout in a working population. We studied n=1,461 employees (mean age 41.3 ± 9.4 yr, 52% men) drawn from a random sample of a pharmaceutical company in Germany. All participants completed the personal burnout subscale of the Copenhagen Burnout Inventory and the Narcissistic Personality Inventory to assess maladaptive (entitlement/exploitativeness) and adaptive (leadership/authority) narcissism. In linear regression analysis, when mutually adjusting for the maladaptive and adaptive narcissism scales, higher adaptive narcissism was associated with lower burnout scores (ß=-0.04, pburnout scores (ß=0.04, pburnout scores (all p-valuesburnout. While maladaptive narcissism was associated with increased levels of burnout symptoms, adaptive narcissism was associated with fewer burnout symptoms.

  11. Kinetics of diamond-silicon reaction under high pressure-high temperature conditions

    Science.gov (United States)

    Pantea, Cristian

    In this dissertation work, the kinetics of the reaction between diamond and silicon at high pressure-high temperature conditions was investigated. This study was motivated by the extremely limited amount of information related to the kinetics of the reaction in diamond-silicon carbide composites formation. It was found that the reaction between diamond and melted silicon and the subsequent silicon carbide formation is a two-stage process. The initial stage is a result of direct reaction of melted silicon with carbon atoms from the diamond surface, the phase boundary reaction. Further growth of SiC is much more complicated and when the outer surfaces of diamond crystals are covered with the silicon carbide layer it involves diffusion of carbon and silicon atoms through the SiC layer. The reaction takes place differently for the two regions of stability of carbon. In the graphite-stable region, the reaction between diamond and melted silicon is associated with the diamond-to-graphite phase transition, while in the diamond-stable region there is no intermediary step for the reaction. The data obtained at HPHT were fitted by the Avrami-Erofeev equation. It was found that the reaction is isotropic, the beta-SiC grown on different faces of the diamond crystals showing the same reaction rate, and that the controlling mechanism for the reaction is the diffusion. In the graphite-stable region the activation energy, 402 kJ/mol is slightly higher than in the diamond-stable region, 260 kJ/mol, as the reaction between diamond and melted silicon is associated with the diamond-to-graphite phase transition, which has higher activation energy. In the diamond-stable region, the calculated activation energy is higher for micron size diamond powders (≈260 kJ/mol), while for nanocrystalline diamond powders a lower value of 170 kJ/mol was obtained. This effect was attributed to nanocrystalline structure and strained bonds within grain boundaries in SiC formed from nanosize diamond

  12. Method of Assembling a Silicon Carbide High Temperature Anemometer

    Science.gov (United States)

    Okojie, Robert S. (Inventor); Fralick, Gustave C. (Inventor); Saad, George J. (Inventor)

    2004-01-01

    A high temperature anemometer includes a pair of substrates. One of the substrates has a plurality of electrodes on a facing surface, while the other of the substrates has a sensor cavity on a facing surface. A sensor is received in the sensor cavity, wherein the sensor has a plurality of bondpads, and wherein the bondpads contact the plurality of electrodes when the facing surfaces are mated with one another. The anemometer further includes a plurality of plug-in pins, wherein the substrate with the cavity has a plurality of trenches with each one receiving a plurality of plug-in pins. The plurality of plug-in pins contact the plurality of electrodes when the substrates are mated with one another. The sensor cavity is at an end of one of the substrates such that the sensor partially extends from the substrate. The sensor and the substrates are preferably made of silicon carbide.

  13. High Strength Silicon Carbide Foams and Their Deformation Behavior

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Silicon carbide (SiC) foams with a continuously connected open-cell structure were prepared and characterized for their mechanical performance. The apparent densities of SiC foams were controlled between about 0.4 and 1.3 g/cm3, with corresponding compressive strengths ranging from about 13 to 60 MPa and flexural strengths from about 8 to 30 MPa. Compressive testing of the SiC foams yielded stress-strain curves with only one linear-elastic region, which is different from those reported on ceramic foams in literature. This can possibly be attributed to the existence of filaments with fine, dense and high strength microstructures. The SiC and the filaments respond homogeneously to applied loading.

  14. Silicon Carbide Diodes Characterization at High Temperature and Comparison With Silicon Devices

    Science.gov (United States)

    Lebron-Velilla, Ramon C.; Schwarze, Gene E.; Gardner, Brent G.; Adams, Jerry D., Jr.

    2004-01-01

    Commercially available silicon carbide (SiC) Schottky diodes from different manufacturers rated at 200, 300, 600, and 1200 V, were electrically tested and characterized as a function of temperature up to 300 C. Electrical tests included both steady state and dynamic tests. Steady state tests produced forward and reverse I-V characteristic curves. Transient tests evaluated the switching performance of the diodes in either a hard-switched DC to DC buck converter or a half-bridge boost converter. For evaluation and comparison purposes, the same tests were performed with current state-of-the-art ultra fast silicon (Si) pn-junction diodes of similar ratings and also a Si Schottky diode. The comparisons made were forward voltage drop at rated current, reverse current at rated voltage, and turn-off peak reverse recovery current and reverse recovery time. In addition, efficiency measurements were taken for the buck DC to DC converter using both the SiC Schottky diodes and the Si pn-junction diodes at different temperatures and frequencies. The test results showed that at high temperature, the forward voltage drop for SiC Schottky diodes is higher than the forward drop of the ultra fast Si pn-junction diodes. As the temperature increased, the forward voltage drop of the SiC Schottky increased while for the ultra fast Si pn-junction diodes, the forward voltage drop decreased as temperature increased. For the elevated temperature steady state reverse voltage tests, the SiC Schottky diodes showed low leakage current at their rated voltage. Likewise, for the transient tests, the SiC Schottky diodes displayed low reverse recovery currents over the range of temperatures tested. Conversely, the Si pn-junction diodes showed increasing peak reverse current values and reverse recovery times with increasing temperature. Efficiency measurements in the DC to DC buck converter showed the advantage of the SiC Schottky diodes over the ultra fast Si pn-junction diodes, especially at the

  15. STATUS OF HIGH FLUX ISOTOPE REACTOR IRRADIATION OF SILICON CARBIDE/SILICON CARBIDE JOINTS

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Yutai [ORNL; Koyanagi, Takaaki [ORNL; Kiggans, Jim [ORNL; Cetiner, Nesrin [ORNL; McDuffee, Joel [ORNL

    2014-09-01

    Development of silicon carbide (SiC) joints that retain adequate structural and functional properties in the anticipated service conditions is a critical milestone toward establishment of advanced SiC composite technology for the accident-tolerant light water reactor (LWR) fuels and core structures. Neutron irradiation is among the most critical factors that define the harsh service condition of LWR fuel during the normal operation. The overarching goal of the present joining and irradiation studies is to establish technologies for joining SiC-based materials for use as the LWR fuel cladding. The purpose of this work is to fabricate SiC joint specimens, characterize those joints in an unirradiated condition, and prepare rabbit capsules for neutron irradiation study on the fabricated specimens in the High Flux Isotope Reactor (HFIR). Torsional shear test specimens of chemically vapor-deposited SiC were prepared by seven different joining methods either at Oak Ridge National Laboratory or by industrial partners. The joint test specimens were characterized for shear strength and microstructures in an unirradiated condition. Rabbit irradiation capsules were designed and fabricated for neutron irradiation of these joint specimens at an LWR-relevant temperature. These rabbit capsules, already started irradiation in HFIR, are scheduled to complete irradiation to an LWR-relevant dose level in early 2015.

  16. Can a single question effectively screen for burnout in Australian cancer care workers?

    Directory of Open Access Journals (Sweden)

    Girgis Afaf

    2010-12-01

    Full Text Available Abstract Background Burnout has important clinical and professional implications among health care workers, with high levels of burnout documented in oncology staff. The aim of this study was to ascertain how well a brief single-item measure could be used to screen for burnout in the Australian oncology workforce. Methods During 2007, 1322 members of the Clinical Oncological Society of Australia were invited to participate in a cross-sectional nationwide survey; 740 (56% of eligible members consented and completed the survey. Data from the 638 consenting members who reported that their work involved direct patient contact were included in the secondary analyses reported in this paper. Burnout was assessed using the MBI Human Services Survey Emotional Exhaustion sub-scale and a single-item self-defined burnout scale. Results Emotional exhaustion was "high" in 33% of the sample when assessed by the psychometrically validated MBI. The single-item burnout measure identified 28% of the sample who classified themselves as "definitely burning out", "having persistent symptoms of burnout", or "completely burned out". MBI Emotional Exhaustion was significantly correlated with the single-item burnout measure (r = 0.68, p 2 of 0.5 (p Conclusions The moderate to high correlation between the single-item self-defined burnout measure and the emotional exhaustion component of burnout suggest that this single item can effectively screen for burnout in health care settings which are time-poor for assessing burnout more comprehensively.

  17. HIGH FREQUENCY INDUCTION WELDING OF HIGH SILICON STEEL TUBES

    Directory of Open Access Journals (Sweden)

    Ricardo Miranda Alé

    2012-06-01

    Full Text Available High-Si steel is a low cost alternative for the fabrication of tubular structures resistant to atmospheric corrosion. However, the literature has often pointed out that steels presenting a higher Si content and/or a lower Mn/Si ratio have higher susceptibility to defects at the weld bond line during HFIW (High Frequency Induction Welding process, which has been widely used for manufacturing small diameter tubes. In this study the effect of the HFIW conditions on the quality of steel tubes with high-Si content and low Mn/Si ratio is investigated. The quality of welded tubes was determined by flare test and the defects in the bond line were identified by SEM. It has been found that higher welding speeds, V-convergence angles and power input should be applied in welding of high-Si steel, when compared to similar strength C-Mn steel.

  18. Fabrication of High-Temperature-Stable Thermoelectric Generator Modules Based on Nanocrystalline Silicon

    Science.gov (United States)

    Kessler, V.; Dehnen, M.; Chavez, R.; Engenhorst, M.; Stoetzel, J.; Petermann, N.; Hesse, K.; Huelser, T.; Spree, M.; Stiewe, C.; Ziolkowski, P.; Schierning, G.; Schmechel, R.

    2014-05-01

    High-temperature-stable thermoelectric generator modules (TGMs) based on nanocrystalline silicon have been fabricated, characterized by the Harman technique, and measured in a generator test facility at the German Aerospace Center. Starting with highly doped p- and n-type silicon nanoparticles from a scalable gas-phase process, nanocrystalline bulk silicon was obtained using a current-activated sintering technique. Electrochemical plating methods were employed to metalize the nanocrystalline silicon. The specific electrical contact resistance ρ c of the semiconductor-metal interface was characterized by a transfer length method. Values as low as ρ c cold-side temperature of 300°C.

  19. Silicon clathrates and carbon analogs: high pressure synthesis, structure, and superconductivity.

    Science.gov (United States)

    Yamanaka, Shoji

    2010-02-28

    Compounds with cage-like structures of elemental silicon and carbon are comparatively reviewed. Barium containing silicon clathrate compounds isomorphous with type I gas hydrates were prepared using high pressure and high temperature (HPHT) conditions, and found to become superconductors. The application of HPHT conditions to Zintl binary silicides have produced a number of silicon-rich cage-like structures including new clathrate structures; most of them are superconductors. Carbon analogs of silicon clathrates can be prepared by 3D polymerization of C(60) under HPHT conditions, which are new allotropes of carbon with expanded framework structures. The crystal chemistry and characteristic properties of some related compounds are also reviewed.

  20. Do low burnout and high work engagement always go hand in hand?: investigation of the energy and identification dimensions in longitudinal data.

    Science.gov (United States)

    Mäkikangas, Anne; Feldt, Taru; Kinnunen, Ulla; Tolvanen, Asko

    2012-01-01

    The aim of the present 2-year follow-up study among young managers (N=433) was to investigate the intraindividual developmental patterns of burnout and work engagement as well as their interconnections. More specifically, we examined the interconnectedness of the varying patterns (i.e., latent classes) of exhaustion and vigor (i.e., the energy dimension) and cynicism and dedication (i.e., the identification dimension) across time. The latent class solutions supported by the growth mixture modeling indicated four latent classes for exhaustion and five for vigor. In addition, four latent classes were found for cynicism and six for dedication. Cynicism and dedication represented opposites with a strong negative relationship, whereas exhaustion and vigor were not connected and seemed to be two independent constructs. Overall, the present findings confirmed the results of earlier studies relating to the energy and identification continua and underlined the importance of investigating the subdimensions of burnout and work engagement. Thus, our study showed that high cynicism goes hand in hand with low dedication, but high exhaustion and low vigor do not necessarily appear together.

  1. Burnout in United States Academic Chairs of Radiation Oncology Programs

    Energy Technology Data Exchange (ETDEWEB)

    Kusano, Aaron S. [Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington (United States); Thomas, Charles R., E-mail: thomasch@ohsu.edu [Department of Radiation Medicine, Knight Cancer Institute/Oregon Health and Science University, Portland, Oregon (United States); Bonner, James A. [Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, Alabama (United States); DeWeese, Theodore L. [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland (United States); Formenti, Silvia C. [Department of Radiation Oncology, New York University, New York, New York (United States); Hahn, Stephen M. [Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Mittal, Bharat B. [Department of Radiation Oncology, Northwestern University, Chicago, Ilinois (United States)

    2014-02-01

    Purpose: The aims of this study were to determine the self-reported prevalence of burnout in chairs of academic radiation oncology departments, to identify factors contributing to burnout, and to compare the prevalence of burnout with that seen in other academic chair groups. Methods and Materials: An anonymous online survey was administered to the membership of the Society of Chairs of Academic Radiation Oncology Programs (SCAROP). Burnout was measured with the Maslach Burnout Inventory-Human Services Survey (MBI-HSS). Results: Questionnaires were returned from 66 of 87 chairs (76% response rate). Seventy-nine percent of respondents reported satisfaction with their current positions. Common major stressors were budget deficits and human resource issues. One-quarter of chairs reported that it was at least moderately likely that they would step down in the next 1 to 2 years; these individuals demonstrated significantly higher emotional exhaustion. Twenty-five percent of respondents met the MBI-HSS criteria for low burnout, 75% for moderate burnout, and none for high burnout. Group MBI-HSS subscale scores demonstrated a pattern of moderate emotional exhaustion, low depersonalization, and moderate personal accomplishment, comparing favorably with other specialties. Conclusions: This is the first study of burnout in radiation oncology chairs with a high response rate and using a validated psychometric tool. Radiation oncology chairs share similar major stressors to other chair groups, but they demonstrate relatively high job satisfaction and lower burnout. Emotional exhaustion may contribute to the anticipated turnover in coming years. Further efforts addressing individual and institutional factors associated with burnout may improve the relationship with work of chairs and other department members.

  2. Low noise high-Tc superconducting bolometers on silicon nitride membranes for far-infrared detection

    NARCIS (Netherlands)

    Nivelle, de M.J.M.E.; Bruijn, M.P.; Vries, de R.; Wijnbergen, J.J.; Korte, de P.A.J.; Sanchez, S.; Elwenspoek, M.; Heidenblut, T.; Schwierzi, B.; Michalke, W.; Steinbeiss, E.

    1997-01-01

    High-Tc GdBa2Cu3O7 – delta superconductor bolometers with operation temperatures near 89 K, large receiving areas of 0.95 mm2 and very high detectivity have been made. The bolometers are supported by 0.62 µm thick silicon nitride membranes. A specially developed silicon-on-nitride layer was used to

  3. Deep anisotropic dry etching of silicon microstructures by high-density plasmas

    NARCIS (Netherlands)

    Blauw, M.A.

    2004-01-01

    This thesis deals with the dry etching of deep anisotropic microstructures in monocrystalline silicon by high-density plasmas. High aspect ratio trenches are necessary in the fabrication of sensitive inertial devices such as accellerometers and gyroscopes. The etching of silicon in fluorine-based

  4. Impurity distribution and reduction behaviour of quartz in the production of high purity silicon

    OpenAIRE

    Dal Martello, Elena

    2012-01-01

    The production of solar grade silicon is based on the use of expensive high purity carbon and quartz feedstock as well as various silicon refining techniques. Impurities in the feedstock materials enter the silicon during the carbothermic reduction of quartz. The knowledge of the impurity distribution/removal in the feedstock and in the carbothermic reduction process is necessary for targeting less pure and cheaper raw materials.The aim of the present study is to investigate the impurity dist...

  5. A multicenter study on the validation of the Burnout Battery: a new visual analog scale to screen job burnout in oncology professionals.

    Science.gov (United States)

    Deng, Yao-Tiao; Liu, Jie; Zhang, Jie; Huang, Bo-Yan; Yi, Ting-Wu; Wang, Yu-Qing; Zheng, Bo; Luo, Di; Du, Pei-Xin; Jiang, Yu

    2017-08-01

    The objective of the study is to develop a novel tool-the Burnout Battery-for briefly screening burnout among oncology professionals in China and assessing its validity. A multicenter study was conducted in doctors and nurses of the oncology departments in China from November 2014 to May 2015. The Burnout Battery was administered with the Maslach Burnout Inventory-Human Services Survey (MBI-HSS) and the Doctors' Job Burnout Questionnaire. Of 538 oncology doctors and nurses who completed all the survey, using MBI-HSS as the standard tool for measuring burnout, 52% had emotional exhaustion, 39.4% had depersonalization, and 59.3% had a low sense of personal accomplishment. Receiver operating characteristic curve analyses showed that the best cut-off of the Burnout Battery was the battery with 3 bars, which yielded best sensitivity and specificity against all the 3 subscales of MBI-HSS. With this cut-off, nearly half of Chinese oncology professionals (46.8%) had burnout. The Burnout Battery correlated significantly with subscales of the MBI-HSS and the Doctors' Job Burnout Questionnaire. In multiple logistic regression analysis, those who worked more than 60 hours per week and who thought clinical work was the most stressful part of their job were more likely to experience burnout. Chinese oncology professionals exhibit high levels of burnout. The Burnout Battery appears to be a simple and useful tool for screening burnout. Working long hours and perceiving clinical work as the most stressful part of the job were the main factors associated with burnout. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Factors associated to Burnout Syndrome in High School Teachers in Cali, Colombia [Factores asociados al síndrome de burnout en docentes de colegios de la ciudad de Cali, Colombia

    Directory of Open Access Journals (Sweden)

    Fátima Díaz Bambula

    2012-03-01

    Full Text Available The goal of the study was to locate factors related to burnout syndrome in teachers of two formal private and public educational institutions from Cali, Colombia. The syndrome’s dimensions (emotional exhaustion, depersonalization and reduced sense of personal accomplishment and their relation to organizational factors, the stress of the role and socio-demographic characteristics of the teachers were described. The Modified Burnout in teachers Questionnaire [CBP-M] was applied to a sample of 82 teachers from one public and one private school. Results show a low level of burnout syndrome in both institutions. An association with the levels of stress of role and organizational factors such as supervision, job conditions and professional worries was found. The socio-demographic characteristics did not show significant relations with the syndrome, with the exception of the level of education in which the teachers give classes

  7. High-flux solar furnace processing of crystalline silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S.; Pitts, J.R. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Menna, P. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)]|[ENEA-Centro Ricerche Fotovoltaiche, Portici 80055 (Italy); Landry, M.D. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Gee, J.M. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)]|[Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Ciszek, T.F. [National Renewable Energy Laboratory, Golden, Colorado, 80401 (United States)

    1997-02-01

    We studied the processing of crystalline-silicon solar cells using a 10-kW, high-flux solar furnace (HFSF). Major findings of this study include: (1) hydrogenated amorphous silicon films deposited on glass substrates can be converted to microcrystalline silicon by solid-phase crystallization in 5 seconds or less in the HFSF; (2) the presence of concentrated sunlight enhances the diffusion of phosphorus into silicon from a spin-on dopant source; (3) the combination of a porous-silicon surface layer and photo-enhanced impurity diffusion is very effective in gettering impurities from a metallurgical-grade silicon wafer or thin-layer silicon deposited using liquid-phase epitaxy; (4) a 14.1{percent}-efficient crystalline-silicon solar cell with an area of 4.6cm{sup 2} was fabricated using the HFSF for simultaneous diffusion of front n{sup +}-p and back p-p{sup +} junctions; and (5) we have shown that the HFSF can be used to texture crystalline-silicon surfaces and to anneal metal contacts printed on a silicon solar cell. {copyright} {ital 1997 American Institute of Physics.}

  8. High-flux solar furnace processing of crystalline silicon solar cells

    Science.gov (United States)

    Tsuo, Y. S.; Pitts, J. R.; Menna, P.; Landry, M. D.; Gee, J. M.; Ciszek, T. F.

    1997-02-01

    We studied the processing of crystalline-silicon solar cells using a 10-kW, high-flux solar furnace (HFSF). Major findings of this study include: (1) hydrogenated amorphous silicon films deposited on glass substrates can be converted to microcrystalline silicon by solid-phase crystallization in 5 seconds or less in the HFSF; (2) the presence of concentrated sunlight enhances the diffusion of phosphorus into silicon from a spin-on dopant source; (3) the combination of a porous-silicon surface layer and photo-enhanced impurity diffusion is very effective in gettering impurities from a metallurgical-grade silicon wafer or thin-layer silicon deposited using liquid-phase epitaxy; (4) a 14.1%-efficient crystalline-silicon solar cell with an area of 4.6 cm2 was fabricated using the HFSF for simultaneous diffusion of front n+-p and back p-p+ junctions; and (5) we have shown that the HFSF can be used to texture crystalline-silicon surfaces and to anneal metal contacts printed on a silicon solar cell.

  9. Low Cost, High Efficiency, Silicon Based Photovoltaic Devices

    Science.gov (United States)

    2015-08-27

    93 (2004). [102] C. Chartier , S. Bastide, C. Lévy-Clément, Metal-assisted chemical etching of silicon in HF–H2O2, Electrochimica Acta, 53 (2008...ACS Applied Materials & Interfaces, 3 (2011) 3866-3873. [104] C. Chartier , S. Bastide, C. Levyclement, Metal-assisted chemical etching of silicon in

  10. Highly permeable and mechanically robust silicon carbide hollow fiber membranes

    NARCIS (Netherlands)

    de Wit, Patrick; Kappert, Emiel; Lohaus, T.; Wessling, Matthias; Nijmeijer, Arian; Benes, Nieck Edwin

    2015-01-01

    Silicon carbide (SiC) membranes have shown large potential for applications in water treatment. Being able to make these membranes in a hollow fiber geometry allows for higher surface-to-volume ratios. In this study, we present a thermal treatment procedure that is tuned to produce porous silicon

  11. Highly permeable and mechanically robust silicon carbide hollow fiber membranes

    NARCIS (Netherlands)

    Wit, de P.; Kappert, Emiel J.; Lohaus, T.; Wessling, M.; Nijmeijer, A.; Benes, N.E.

    2015-01-01

    Silicon carbide (SiC) membranes have shown large potential for applications in water treatment. Being able to make these membranes in a hollow fiber geometry allows for higher surface-to-volume ratios. In this study, we present a thermal treatment procedure that is tuned to produce porous silicon ca

  12. Job Stressors, Personality and Burnout in Primary School Teachers

    Science.gov (United States)

    Kokkinos, Constantinos M.

    2007-01-01

    Background: Teaching is considered a highly stressful occupation. Burnout is a negative affective response occurring as a result of chronic work stress. While the early theories of burnout focused exclusively on work-related stressors, recent research adopts a more integrative approach where both environmental and individual factors are studied.…

  13. Novice Teachers' Experience of Teaching: A Dynamic Aspect of Burnout

    Science.gov (United States)

    Gavish, Bella; Friedman, Isaac A.

    2010-01-01

    This article addresses the question of how novice teachers perceive their work environment and how their perceptions affect burnout. Data were obtained from a questionnaire administered to novice teachers at the beginning and at the end of the school year. It was found that (1) novice teachers experienced high levels of burnout as early as the…

  14. Burnout in Turkish Computer Teachers: Problems and Predictors

    Science.gov (United States)

    Deryakulu, Deniz

    2006-01-01

    Burnout is known to be a job-related syndrome. Freudenberger (1974) introduced the term "burnout" to describe the inability to function effectively in one's job as a consequence of prolonged and extensive job-related stress. Teaching has been identified as a highly stressful job. Selye (1974, as cited in Iwanicki, 1983) used the terms "eustress"…

  15. High deposition rate nanocrystalline silicon with enhanced homogeneity

    Energy Technology Data Exchange (ETDEWEB)

    Verkerk, Arjan; Rath, Jatindra K.; Schropp, Ruud [Section Nanophotonics-Physics of Devices, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, P.O. Box 80000, 3508 TA Utrecht (Netherlands)

    2010-03-15

    High rate growth of hydrogenated nanocrystalline silicon (nc-Si:H) brings additional challenges for the homogeneity in the growth direction, since the start-up effects affect a larger portion of the film, and the very high degree of depletion increases the influence of back diffusion from the inactive region into the plasma zone. It was calculated that back diffusion plays a role in the regime for high deposition rate (4.5 nm/s) via the residence time for particles in the plasma and the corresponding diffusion length for silane from outside the plasma. The stabilization time for back diffusion was derived and found to be on the order of tens of seconds. Experiment showed that the incubation layer for nc-Si:H is very thick in films deposited at a high rate compared to films deposited in a regime of lower deposition rate. The use of a hydrogen plasma start greatly reduced this incubation layer. Further control of the crystalline fraction could be achieved via slight reduction of the degree of depletion via the silane flow. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  16. Silicone elastomers with high dielectric permittivity and high dielectric breakdown strength based on dipolar copolymers

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Yu, Liyun; Daugaard, Anders Egede;

    2014-01-01

    Dielectric elastomers (DES) are a promising new transducer technology, but high driving voltages limit their current commercial potential. One method used to lower driving voltage is to increase dielectric permittivity of the elastomer. A novel silicone elastomer system with high dielectric permi......-4-nitrobenzene. Here, a high increase in dielectric permittivity (similar to 70%) was obtained without compromising other favourable DE properties such as elastic modulus, gel fraction, dielectric loss and electrical breakdown strength. © 2014 Elsevier Ltd. All rights reserved....

  17. Calidad de vida y estrés laboral: la incidencia del Burnout en el deporte de alto rendimiento madrileño. Quality of life and job stress: Burnout among high performance sport professionals from Madrid.

    OpenAIRE

    Martínez del Castillo, Jesús; Martín Rodríguez, María; Jiménez Beatty, Jose Emilio; Campos Izquierdo, Antonio

    2007-01-01

    ResumenEn la literatura sobre la psicología de la salud en las organizaciones es generalmente aceptado que el Burnout (Síndrome de quemarse por el trabajo) aparece como consecuencia de un estrés laboral crónico excesivo que provoca una disminución de la habilidad en el desempeño de la actividad profesional y la aparición de diferentes problemas de salud en quien lo padece. El Burnout (Síndrome de quemarse por el trabajo) ha sido conceptualizado como un síndrome psicológico tridimensional de a...

  18. Burnout in the intensive care unit professionals

    Science.gov (United States)

    Chuang, Chien-Huai; Tseng, Pei-Chi; Lin, Chun-Yu; Lin, Kuan-Han; Chen, Yen-Yuan

    2016-01-01

    , suggesting that ICU professionals may suffer from a high level of burnout, potentially threatening patient care. Future work should address the effective management of the factors negatively affecting ICU professionals. PMID:27977605

  19. Fluorescent porous silicon biological probes with high quantum efficiency and stability.

    Science.gov (United States)

    Tu, Chang-Ching; Chou, Ying-Nien; Hung, Hsiang-Chieh; Wu, Jingda; Jiang, Shaoyi; Lin, Lih Y

    2014-12-01

    We demonstrate porous silicon biological probes as a stable and non-toxic alternative to organic dyes or cadmium-containing quantum dots for imaging and sensing applications. The fluorescent silicon quantum dots which are embedded on the porous silicon surface are passivated with carboxyl-terminated ligands through stable Si-C covalent bonds. The porous silicon bio-probes have shown photoluminescence quantum yield around 50% under near-UV excitation, with high photochemical and thermal stability. The bio-probes can be efficiently conjugated with antibodies, which is confirmed by a standard enzyme-linked immunosorbent assay (ELISA) method.

  20. Optical properties of highly nonlinear silicon-organic hybrid (SOH) waveguide geometries.

    Science.gov (United States)

    Vallaitis, Thomas; Bogatscher, Siegwart; Alloatti, Luca; Dumon, Pieter; Baets, Roel; Scimeca, Michelle L; Biaggio, Ivan; Diederich, François; Koos, Christian; Freude, Wolfgang; Leuthold, Juerg

    2009-09-28

    Geometry, nonlinearity, dispersion and two-photon absorption figure of merit of three basic silicon-organic hybrid waveguide designs are compared. Four-wave mixing and heterodyne pump-probe measurements show that all designs achieve high nonlinearities. The fundamental limitation of two-photon absorption in silicon is overcome using silicon-organic hybrid integration, with a five-fold improvement for the figure of merit (FOM). The value of FOM = 2.19 measured for silicon-compatible nonlinear slot waveguides is the highest value published.

  1. Preparation of electrochemically active silicon nanotubes in highly ordered arrays

    Directory of Open Access Journals (Sweden)

    Tobias Grünzel

    2013-10-01

    Full Text Available Silicon as the negative electrode material of lithium ion batteries has a very large capacity, the exploitation of which is impeded by the volume changes taking place upon electrochemical cycling. A Si electrode displaying a controlled porosity could circumvent the difficulty. In this perspective, we present a preparative method that yields ordered arrays of electrochemically competent silicon nanotubes. The method is based on the atomic layer deposition of silicon dioxide onto the pore walls of an anodic alumina template, followed by a thermal reduction with lithium vapor. This thermal reduction is quantitative, homogeneous over macroscopic samples, and it yields amorphous silicon and lithium oxide, at the exclusion of any lithium silicides. The reaction is characterized by spectroscopic ellipsometry for thin silica films, and by nuclear magnetic resonance and X-ray photoelectron spectroscopy for nanoporous samples. After removal of the lithium oxide byproduct, the silicon nanotubes can be contacted electrically. In a lithium ion electrolyte, they then display the electrochemical waves also observed for other bulk or nanostructured silicon systems. The method established here paves the way for systematic investigations of how the electrochemical properties (capacity, charge/discharge rates, cyclability of nanoporous silicon negative lithium ion battery electrode materials depend on the geometry.

  2. Occupational stress and burnout among Hong Kong dentists.

    Science.gov (United States)

    Choy, H B; Wong, M C

    2017-08-25

    Professional burnout has been described as a gradual erosion of a person and may be one of the possible consequences of chronic occupational stress. Although occupational stress has been surveyed among dentists in Hong Kong, no study has been published about burnout in the profession. This study aimed to evaluate burnout among Hong Kong dentists and its association with occupational stress. We surveyed a random sample of 1086 registered dentists in Hong Kong, which formed 50% of the local profession. They were mailed an anonymous questionnaire about burnout and occupational stress in 2015. The questionnaire assessed occupational stress, coping strategies, effects of stress, level of burnout, and socio-demographic characteristics of the respondents. Occupational stress assessment concerned 33 stressors in five groups: patient-related, time-related, income-related, job-related, and staff-/technically related. Level of burnout was assessed by the Maslach Burnout Inventory-Human Services Survey (22 items) with three scores: emotional exhaustion, depersonalisation, and personal accomplishment. Completed questionnaires were received from 301 dentists (response rate, 28.3%), of whom 25.4% had a high level of emotional exhaustion, 17.2% had a high level of depersonalisation, and 39.0% had a low level of personal accomplishment. Only 7.0% of respondents, however, had a high level of overall burnout (high emotional exhaustion, high depersonalisation, and low personal accomplishment). A high level of overall burnout was significantly associated with a higher mean score for job-related stressors and lack of postgraduate qualifications (Pburnout. There was a positive association between occupational stress and level of burnout.

  3. [Risk factors and burnout levels in Primary Care nurses: A systematic review].

    Science.gov (United States)

    Gómez-Urquiza, Jose L; Monsalve-Reyes, Carolina S; San Luis-Costas, Concepción; Fernández-Castillo, Rafael; Aguayo-Estremera, Raimundo; Cañadas-de la Fuente, Guillermo A

    2017-02-01

    To determine the risk factors and levels of burnout in Primary Care nurses. A systematic review was performed. CINAHL, CUIDEN, LILACS, PubMed, ProQuest, ScienceDirect and Scopus databases were consulted. Search equations were 'burnout AND community health nursing' and 'burnout AND primary care nursing'. The search was performed in October 2015. The final sample was n=12 studies. Quantitative primary studies that used Maslach Burnout Inventory for burnout assessment in Primary Care nurses were included without restriction by publication date. The main variables were the mean and standard deviation of the three burnout dimensions, high, medium and low prevalence rates of each dimension, and socio-demographic, occupational and psychological variables that potentially influence burnout level. Studies show high prevalence rates, generally between 23% and 31%, of emotional exhaustion. The prevalence rates of high depersonalisation and low personal accomplishment show heterogeneity, varying between 8%-32% and 4%-92% of the sample, respectively. Studies show that older nurses with more seniority, anxiety and depression, among other variables, have higher burnout levels, while nurses with higher salary, high job satisfaction, organisational support, and good self-concept have less burnout. High emotional exhaustion is the main affected dimension of burnout in Primary Care nursing. There is heterogeneity in depersonalisation and personal accomplishment. Burnout must be prevented in these professionals, by increasing protective factors and monitoring its appearance in those with risk factors. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  4. High Power Broadband Multispectral Source on a Hybrid Silicon Chip

    Science.gov (United States)

    2017-03-14

    silicon photonic network on chip,” Optica 3(7), 785–786 (2016). [8] Stanton, E. J., Heck, M. J. R., Bovington, J., Spott, A., and Bowers, J. E...Hutchinson, J., Shin, J.-H., Fish, G., and Fang, A., “Integrated silicon photonic laser sources for telecom and datacom,” in [National Fiber Optic...Mid-infrared wavelength conversion in silicon waveguides using ultracompact telecom -band-derived pump source,” Nat. Photon. 4(8), 561–564 (2010

  5. Prevalence of burnout in a sample of Brazilian teachers

    Directory of Open Access Journals (Sweden)

    Pedro R. Gil-Monte

    2011-12-01

    Full Text Available Background and Objectives: Burnout is a psychological response to chronic work-related stress of an interpersonal and emotional nature. Brazilian law have already contemplated burnout syndrome as a mental and behavioural disorder related to work. The aim of this study was to identify the prevalence of burnout in a sample of Brazilian teachers. Methods: The sample was composed of 714 teachers from 8 schools in Porto Alegre and its metropolitan area (Brazil. The levels of burnout were evaluated by the Spanish Burnout Inventory, educational version (SBI-Ed. In addition, Psychosomatic disorders were estimated by the UNIPSICO subscale. Results: The percentage of participants who indicated high levels of burnout was 12 % (Profile 1, and 5.6% fell into Profile 2 because they were affected by strong feelings of guilt. Moreover, participants with high scores on the SBI dimensions (low on Enthusiasm toward the job scored significantly higher on psychosomatic disorders than participants with low scores. Conclusions: Based on psychometric considerations, participants who fit Profile 2 of burnout could be considered burnout cases according to Brazilian legislation. However, using a clinical interview to make the diagnosis is recommended.

  6. Burnout among primary care physicians: a systematic review

    Directory of Open Access Journals (Sweden)

    Stephanie Giulianne Silva Morelli

    2015-03-01

    Full Text Available Objectives: to analyze the associations between burnout syndrome and individual and work-related characteristics among primary care physicians. Methods: a systematic review was performed using the Medline (PubMed, SciELO, Lilacs and Cochrane databases. In November, 2013, we ran a search based on the descriptors: “professional burnout”, “health personnel”, and “primary care”. We assessed 2,416 titles and 18 studies were selected. Results: the prevalence of burnout was high among primary care physicians. Burnout was associated with physical illnesses, mental disorders, and alcohol and substance abuse. Physicians who had higher levels of emotional exhaustion were more likely to be absent from work, and to change their job. Physicians suffering from burnout were also more likely to increase pharmaceutical expenditure per patient. The work-related characteristics associated with burnout were: length of employment in primary care, number of working hours per week, number of patients attended, type of employment contract, teaching activity, holiday period, and difficulties in dealing with other staff. Conclusion: the high prevalence of burnout among primary care physicians is a major concern for policy makers, since primary care is the cornerstone of health systems, and burnout syndrome can jeopardize the quality of care provided to populations, and the effectiveness of the entire health care system. Understanding the factors associated with burnout allows the development of strategies for intervention and prevention.

  7. Silicon/Porous Silicon Composite Membrane for High Sensitivity Pressure Sensor

    Science.gov (United States)

    2009-07-21

    Francia et al 2000). Stoney’s stress equation is given by equation 3.1 as Valve Vacuum Pump Pressure sensor with Si/PS composite membrane DC... Francia D G, V. La Ferrara, L. Lancellotti and L. Quercia (2000) Stress measurement technique to monitor porous silicon processing, Journal of

  8. Silicon Valley: Planet Startup : Disruptive Innovation, Passionate Entrepreneurship & High-tech Startups

    NARCIS (Netherlands)

    Ester, P.; Maas, A.

    2016-01-01

    For decades now, Silicon Valley has been the home of the future. It's the birthplace of the world's most successful high-tech companies-including Apple, Yahoo, Google, Facebook, Twitter, and many more. So what's the secret? What is it about Silicon Valley that fosters entrepreneurship and innovation

  9. Fabrication of High-Frequency pMUT Arrays on Silicon Substrates

    DEFF Research Database (Denmark)

    Pedersen, Thomas; Zawada, Tomasz; Hansen, Karsten

    2010-01-01

    A novel technique based on silicon micromachining for fabrication of linear arrays of high-frequency piezoelectric micromachined ultrasound transducers (pMUT) is presented. Piezoelectric elements are formed by deposition of lead zirconia titanate into etched features of a silicon substrate...

  10. Silicon-Carbide Power MOSFET Performance in High Efficiency Boost Power Processing Unit for Extreme Environments

    Science.gov (United States)

    Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Del Castillo, Linda Y.; Fitzpatrick, Fred; Chen, Yuan

    2016-01-01

    Silicon-Carbide device technology has generated much interest in recent years. With superior thermal performance, power ratings and potential switching frequencies over its Silicon counterpart, Silicon-Carbide offers a greater possibility for high powered switching applications in extreme environment. In particular, Silicon-Carbide Metal-Oxide- Semiconductor Field-Effect Transistors' (MOSFETs) maturing process technology has produced a plethora of commercially available power dense, low on-state resistance devices capable of switching at high frequencies. A novel hard-switched power processing unit (PPU) is implemented utilizing Silicon-Carbide power devices. Accelerated life data is captured and assessed in conjunction with a damage accumulation model of gate oxide and drain-source junction lifetime to evaluate potential system performance at high temperature environments.

  11. Physician burnout: A neurologic crisis.

    Science.gov (United States)

    Sigsbee, Bruce; Bernat, James L

    2014-12-09

    The prevalence of burnout is higher in physicians than in other professions and is especially high in neurologists. Physician burnout encompasses 3 domains: (1) emotional exhaustion: the loss of interest and enthusiasm for practice; (2) depersonalization: a poor attitude with cynicism and treating patients as objects; and (3) career dissatisfaction: a diminished sense of personal accomplishment and low self-value. Burnout results in reduced work hours, relocation, depression, and suicide. Burned-out physicians harm patients because they lack empathy and make errors. Studies of motivational factors in the workplace suggest several preventive interventions: (1) Provide counseling for physicians either individually or in groups with a goal of improving adaptive skills to the stress and rapid changes in the health care environment. (2) Identify and eliminate meaningless required hassle factors such as electronic health record "clicks" or insurance mandates. (3) Redesign practice to remove pressure to see patients in limited time slots and shift to team-based care. (4) Create a culture that promotes career advancement, mentoring, and recognition of accomplishments. © 2014 American Academy of Neurology.

  12. Silicon Avalanche Pixel Sensor for High Precision Tracking

    CERN Document Server

    D'Ascenzo, N; Moon, C S; Morsani, F; Ratti, L; Saveliev, V; Navarro, A Savoy; Xie, Q

    2013-01-01

    The development of an innovative position sensitive pixelated sensor to detect and measure with high precision the coordinates of the ionizing particles is proposed. The silicon avalanche pixel sensors (APiX) is based on the vertical integration of avalanche pixels connected in pairs and operated in coincidence in fully digital mode and with the processing electronics embedded on the chip. The APiX sensor addresses the need to minimize the material budget and related multiple scattering effects in tracking systems requiring a high spatial resolution in the presence of a large occupancy. The expected operation of the new sensor features: low noise, low power consumption and suitable radiation tolerance. The APiX device provides on-chip digital information on the position of the coordinate of the impinging charged particle and can be seen as the building block of a modular system of pixelated arrays, implementing a sparsified readout. The technological challenges are the 3D integration of the device under CMOS ...

  13. High-temperature quantum kinetic effect in silicon nanosandwiches

    Science.gov (United States)

    Bagraev, N. T.; Grigoryev, V. Yu.; Klyachkin, L. E.; Malyarenko, A. M.; Mashkov, V. A.; Romanov, V. V.; Rul, N. I.

    2017-01-01

    The negative-U impurity stripes confining the edge channels of semiconductor quantum wells are shown to allow the effective cooling inside in the process of the spin-dependent transport, with the reduction of the electron-electron interaction. The aforesaid promotes also the creation of composite bosons and fermions by the capture of single magnetic flux quanta on the edge channels under the conditions of low sheet density of carriers, thus opening new opportunities for the registration of the quantum kinetic phenomena in weak magnetic fields at high-temperatures up to the room temperature. As a certain version noted above we present the first findings of the high temperature de Haas-van Alphen, 300 K, quantum Hall, 77 K, effects as well as quantum conductance staircase in the silicon sandwich structure that represents the ultra-narrow, 2 nm, p-type quantum well (Si-QW) confined by the delta barriers heavily doped with boron on the n-type Si (100) surface.

  14. Twin photon pairs in a high-Q silicon microresonator

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Steven; Lu, Xiyuan [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Jiang, Wei C. [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Lin, Qiang, E-mail: qiang.lin@rochester.edu [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York 14627 (United States)

    2015-07-27

    We report the generation of high-purity twin photon pairs through cavity-enhanced non-degenerate four-wave mixing (FWM) in a high-Q silicon microdisk resonator. Twin photon pairs are created within the same cavity mode and are consequently expected to be identical in all degrees of freedom. The device is able to produce twin photons at telecommunication wavelengths with a pair generation rate as large as (3.96 ± 0.03) × 10{sup 5} pairs/s, within a narrow bandwidth of 0.72 GHz. A coincidence-to-accidental ratio of 660 ± 62 was measured, the highest value reported to date for twin photon pairs, at a pair generation rate of (2.47 ± 0.04) × 10{sup 4} pairs/s. Through careful engineering of the dispersion matching window, we have reduced the ratio of photons resulting from degenerate FWM to non-degenerate FWM to less than 0.15.

  15. Mobility and impact ionization in silicon at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Corvasce, C.

    2007-07-01

    In the field of the high-temperature modelling and simulation of semiconductor devices, most of the physical models available to date have been validated only to 400 K, in spite of the fact that the local heating during the stress event can lead to local temperatures well in excess of this limit. This work deals with the mobility and the impact ionization in silicon at high temperature. The mobility has been measured by the Hall technique up to 1000 K thanks to the use of dedicated Ti/TiN interconnections in combination with junction-free van der Pauw resistors, which are intrinsically immune of spurious thermal leakage currents. The hole and the electron impact ionization coefficients have been determined as a function of the electric field up to 673 K and 613 K, respectively, by measurements of the multiplication factor in bipolar and static induction transistors. The results collected in this work represent an extensive reference data set, which is suitable for the calibration of compact models for numerical simulation. (orig.)

  16. Composite silicone rubber of high piezoresistance repeatability filled with nanoparticles

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The ruthenium oxide nanoparticles with size less than 20 nm were fabricated by annealing the metallic ruthenium nanoparticles in air,which were synthesized by using the thermal reduction in the polyol solution.The rutile structure of the ruthenium oxide was proved by using transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).The oxide has good electron conductivity. The surface of the ruthenium oxide was modified by a vinyl silane coupling agent.The assembling of the silane to the oxide surface was proved by Infrared(IR)absorption spectroscopy.By mixing the nanoparticles with poly(methylvinylsiloxane)(PMVS)silicone rubber,a composite filled with dispersive conducting phase was fabricated.The temperature dependent conductivity shows that the electron transportation through composite is mainly dominated by tunneling.The measurement of piezoresistance shows that the composite at low strain has high piezoresistance repeatability.The 3D reconstruction images of the composite filled with carbon black or ruthenium oxide show that the aggregation of the nanoparticles differs much for two composites.The narrow distribution range of the particle size was thought to be the main factor for the high piezoresistance recurrence.

  17. High-Quality Alkyl Monolayers on Silicon Surfaces

    NARCIS (Netherlands)

    Sieval, A.B.; Linke, R.; Zuilhof, H.; Sudh"lter, E.J.R.

    2000-01-01

    Covalent attachment of functionalized monolayers onto silicon surfaces (see Figure for examples) is presented here as a strategy for surface modification. The preparation and structure of both unfunctionalized and functionalized alkyl-based monolayers are described, as are potential applications,

  18. Silicon Carbide Threads For High-Temperature Service

    Science.gov (United States)

    Sawko, Paul M.; Vasudev, Anand

    1991-01-01

    New thread material outperforms silica. Sewing threads containing silicon carbide (SiC) yarn withstand temperatures of more than 1,100 degrees C. Intended for use in stitching thermally insulating blankets.

  19. The fabrication of a double-layer atom chip with through silicon vias for an ultra-high-vacuum cell

    Science.gov (United States)

    Chuang, Ho-Chiao; Lin, Yun-Siang; Lin, Yu-Hsin; Huang, Chi-Sheng

    2014-04-01

    This study presents a double-layer atom chip that provides users with increased diversity in the design of the wire patterns and flexibility in the design of the magnetic field. It is more convenient for use in atomic physics experiments. A negative photoresist, SU-8, was used as the insulating layer between the upper and bottom copper wires. The electrical measurement results show that the upper and bottom wires with a width of 100 µm can sustain a 6 A current without burnout. Another focus of this study is the double-layer atom chips integrated with the through silicon via (TSV) technique, and anodically bonded to a Pyrex glass cell, which makes it a desired vacuum chamber for atomic physics experiments. Thus, the bonded glass cell not only significantly reduces the overall size of the ultra-high-vacuum (UHV) chamber but also conducts the high current from the backside to the front side of the atom chip via the TSV under UHV (9.5 × 10-10 Torr). The TSVs with a diameter of 70 µm were etched through by the inductively coupled plasma ion etching and filled by the bottom-up copper electroplating method. During the anodic bonding process, the electroplated copper wires and TSVs on atom chips also need to pass the examination of the required bonding temperature of 250 °C, under an applied voltage of 1000 V. Finally, the UHV test of the double-layer atom chips with TSVs at room temperature can be reached at 9.5 × 10-10 Torr, thus satisfying the requirements of atomic physics experiments under an UHV environment.

  20. Burnout in university students

    National Research Council Canada - National Science Library

    Carmen Cecilia Caballero D; Edgar Breso Esteve; Orlando González Gutierréz

    2015-01-01

      In order to provide a better understanding and characterization of the nature of academic burnout in university students, a review of the concept, its evolution and extrapolation of the work context...

  1. 'Burnout' among Dutch midwives.

    NARCIS (Netherlands)

    Bakker, R.H.C.; Groenewegen, P.P.; Jabaaij, L.; Meijer, W.; Sixma, H.; Veer, A. de

    1996-01-01

    OBJECTIVE: to determine the effect of workload on 'burnout' having considered work capacity. DESIGN: cross-sectional study. SETTING: Dutch community midwives in independent practice. PARTICIPANTS: 200 Dutch community midwives. MEASUREMENTS: three-week diary recordings, a questionnaire on practice

  2. A Study of Burnout in International and Country of Origin Teachers

    Science.gov (United States)

    Coulter, Mary Ann; Abney, Paul C.

    2009-01-01

    The study examined the extent to which burnout levels of teachers working in international schools differed from the burnout level of teachers working in their country of origin. All participants of the study were Canadian citizens who were educated in Canada, held Ontario College of Teachers certification and were teaching credit courses in high schools offering the Ontario curriculum under the auspice of the Ontario Ministry of Education. All teachers completed the Burnout Test Form 1 - Revised (Jerabeck, Burnout Test Form 1 - Revised, 2001) online. The study found that international teachers had a statistically lower level of burnout than teachers working in their country of origin.

  3. Field effect passivation of high efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Aberle, A.G. (Fraunhofer-Inst. fuer Solare Energiesysteme (ISE), Freiburg (Germany)); Glunz, S. (Fraunhofer-Inst. fuer Solare Energiesysteme (ISE), Freiburg (Germany)); Warta, W. (Fraunhofer-Inst. fuer Solare Energiesysteme (ISE), Freiburg (Germany))

    1993-03-01

    In this paper effective surface recombination velocities S[sub eff] at the rear Si-SiO[sub 2] interface of the presently best one-sun silicon solar cell structure are calculated on the basis of measured oxide parameters. A new cell design is proposed allowing for a control of the surface space charge region by a gate voltage. It is shown that the electric field introduced by the positive fixed oxide charge density typically found at thermally oxidized silicon surfaces and the favorable work function difference between the gate metal aluminum and silicon leads to a reduction of S[sub eff] to values well below 1 cm/s at AM1.5 illumination for n-type as well as p-type silicon. At low illumination levels, however, oxidized n-type silicon has much better surface passivation properties than p-type silicon due to the small hole capture cross section ([sigma][sub n]/[sigma][sub p][approx]1000 at midgap). Only at small illumination intensities for p-type substrates or in the case of poor Si-SiO[sub 2] interface quality the incorporation of a gate electrode on the rear surface is a promising tool for further reducing surface recombination losses. (orig.)

  4. Exploring the relationship between hope and burnout in competitive sport.

    Science.gov (United States)

    Gustafsson, Henrik; Hassmén, Peter; Podlog, Leslie

    2010-12-01

    Researchers have postulated that hope may be an important factor associated with burnout. Consistent with hope theory contentions, low-hope individuals may be susceptible to burnout because they are prone to experience goal blockage, frustration, and negative affect, all of which likely increase the risk of burnout. We examined the relationship between hope and athlete burnout among 178 competitive athletes (63 females and 115 males) aged 15-20 years. Hope was significantly and negatively correlated with all three burnout subscales: emotional/physical exhaustion, a reduced sense of accomplishment, and sport devaluation. Moreover, results of a multivariate analysis of variance showed that low-hope athletes scored significantly higher than medium- and high-hope athletes on all three burnout dimensions. Finally, results revealed that agency thinking was a significant predictor of all burnout dimensions. Frustration over unmet goals and a perceived lack of agency, a characteristic of low-hope athletes, might pose a risk factor in athlete burnout, whereas being able to maintain hope appears to be associated with health and well-being.

  5. A new analytical model of high voltage silicon on insulator (SOI) thin film devices

    Institute of Scientific and Technical Information of China (English)

    Hu Sheng-Dong; Zhang Bo; Li Zhao-Ji

    2009-01-01

    A new analytical model of high voltage silicon on insulator (SOI) thin film devices is proposed, and a formula of silicon critical electric field is derived as a function of silicon film thickness by solving a 2D Poisson equation from an effective ionization rate, with a threshold energy taken into account for electron multiplying. Unlike a conventional silicon critical electric field that is constant and independent of silicon film thickness, the proposed silicon critical electric field increases sharply with silicon film thickness decreasing especially in the case of thin films, and can come to 141 V/μm at a film thickness of 0.1 μm which is much larger than the normal value of about 30 V/μm. From the proposed formula of silicon critical electric field, the expressions of dielectric layer electric field and vertical breakdown voltage (VB,V) are obtained. Based on the model, an ultra thin film can be used to enhance dielectric layer electric field and so increase vertical breakdown voltage for SOI devices because of its high silicon critical electric field, and with a dielectric layer thickness of 2 μm the vertical breakdown voltages reach 852 and 300V for the silicon film thicknesses of 0.1 and 5μm, respectively. In addition, a relation between dielectric layer thickness and silicon film thickness is obtained, indicating a minimum vertical breakdown voltage that should be avoided when an SOI device is designed. 2D simulated results and some experimental results are in good agreement with analytical results.

  6. Predictors of emotional exhaustion, disengagement and burnout among improving access to psychological therapies (IAPT) practitioners.

    Science.gov (United States)

    Westwood, Sophie; Morison, Linda; Allt, Jackie; Holmes, Nan

    2017-04-01

    Among mental health staff, burnout has been associated with undesirable outcomes, such as physical and mental ill-health, high levels of staff turnover and poorer patient care. To estimate the prevalence and predictors of burnout amongst Improving Access to Psychological Therapist (IAPT) practitioners. IAPT practitioners (N = 201) completed an on-line survey measuring time spent per week on different types of work related activity. These were investigated as predictors of burnout (measured using the Oldenburg Burnout Inventory). The prevalence of burnout was 68.6% (95% confidence interval (CI) 58.8-77.3%) among psychological wellbeing practitioners (PWP) and 50.0% (95% CI 39.6-60.4%) among high intensity (HI) therapists. Among PWPs hours of overtime-predicted higher odds of burnout and hours of clinical supervision predicted lower odds of burnout. The odds of burnout increased with telephone hours of patient contact among PWPs who had worked in the service for two or more years. None of the job characteristics significantly predicted burnout among HI therapists. Our results suggest a high prevalence of burnout among IAPT practitioners. Strategies to reduce burnout among PWPs involving reductions in workload, particularly telephone contact and increases in clinical supervision need to be evaluated.

  7. Self-heated silicon nanowires for high performance hydrogen gas detection

    Science.gov (United States)

    Ahn, Jae-Hyuk; Yun, Jeonghoon; Moon, Dong-Il; Choi, Yang-Kyu; Park, Inkyu

    2015-03-01

    Self-heated silicon nanowire sensors for high-performance, ultralow-power hydrogen detection have been developed. A top-down nanofabrication method based on well-established semiconductor manufacturing technology was utilized to fabricate silicon nanowires in wafer scale with high reproducibility and excellent compatibility with electronic readout circuits. Decoration of palladium nanoparticles onto the silicon nanowires enables sensitive and selective detection of hydrogen gas at room temperature. Self-heating of silicon nanowire sensors allows us to enhance response and recovery performances to hydrogen gas, and to reduce the influence of interfering gases such as water vapor and carbon monoxide. A short-pulsed heating during recovery was found to be effective for additional reduction of operation power as well as recovery characteristics. This self-heated silicon nanowire gas sensor will be suitable for ultralow-power applications such as mobile telecommunication devices and wireless sensing nodes.

  8. Stability of high temperature chemical vapor deposited silicon based structures on metals for solar conversion.

    Science.gov (United States)

    Gelard, Isabelle; Chichignoud, Guy; Blanquet, Elisabeth; Xuan, Hoan Nguyen; Cruz, Ruben; Jimenez, Carmen; Sarigiannidou, Eirini; Zaidat, Kader

    2011-09-01

    Highly crystallized silicon layers were grown on metal sheets at high temperature (950 degrees C) by thermal CVD from silane. An intermediate buffer layer was mandatory to prevent interdiffusion and silicide formation but also to compensate lattice parameters and thermal expansion coefficients mismatches between metal and silicon and ideally transfer some crystalline properties (grain size, texture) from the substrate to the silicon layer. After a thermodynamic study, aluminum nitride or titanium nitride diffusion barrier layers were selected and processed by CVD. The structure and the interfaces stabilities of these silicon/nitride/metal stacks were studied by field effect gun scanning and transmission electron microscopy, X-ray diffraction, Raman and energy dispersive X-ray spectroscopy. As a result, TiN deposited by CVD appears to be an efficient material as a buffer layer between steel and silicon.

  9. TRANSFORMATIONS IN NANO-DIAMONDS WITH FORMATION OF NANO-POROUS SILICON CARBIDE AT HIGH PRESSURE

    Directory of Open Access Journals (Sweden)

    V. N. Kovalevsky

    2010-01-01

    Full Text Available The paper contains investigations on regularities of diamond - silicon carbide composite structure formation at impact-wave excitation. It has been determined that while squeezing a porous blank containing Si (SiC nano-diamond by explosive detonation products some processes are taking place such as diamond nano-particles consolidation, reverse diamond transition into graphite, fragments formation from silicon carbide. A method for obtaining high-porous composites with the presence of ultra-disperse diamond particles has been developed. Material with three-dimensional high-porous silicon-carbide structure has been received due to nano-diamond graphitation at impact wave transmission and plastic deformation. The paper reveals nano-diamonds inverse transformation into graphite and its subsequent interaction with the silicon accompanied by formation of silicon-carbide fragments with dimensions of up to 100 nm.

  10. Silicon photomultipliers. Properties and applications in a highly granular calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Feege, Nils

    2008-12-15

    Silicon Photomultipliers (SiPMs) are novel semiconductor-based photodetectors operated in Geiger mode. Their response is not linear, and both their gain and their photon detection efficiency depend on the applied bias voltage and on temperature. The CALICE collaboration investigates several technology options for highly granular calorimeters for the future ILC. The prototype of a scintillator-steel sampling calorimeter with analogue readout for hadrons constructed at DESY and successfully operated in testbeam experiments at DESY, CERN and FNAL by this collaboration is the first large scale application for 7608 SiPMs developed by MEPhI. This thesis deals with properties of the SiPMs used in the calorimeter prototype. The effective numer of pixels of the SiPMs, which influences their saturation behaviour, is extracted from in situ measurements and compared to results obtained for the bare SiPMs. In addition, the effects of temperature and voltage changes on the parameters necessary for the calibration of the SiPMs and the detector are determined. Methods which allow for correcting or compensating these effects are evaluated. An approach to improve the absolute calibration of the temperature sensors in the prototype is described and temperature profiles are studied. Finally, a procedure to adjust the light yield of the cells of the prototype is presented. The results of the application of this procedure during the commissioning of the detector at FNAL are discussed. (orig.)

  11. High Temperature Dynamic Pressure Measurements Using Silicon Carbide Pressure Sensors

    Science.gov (United States)

    Okojie, Robert S.; Meredith, Roger D.; Chang, Clarence T.; Savrun, Ender

    2014-01-01

    Un-cooled, MEMS-based silicon carbide (SiC) static pressure sensors were used for the first time to measure pressure perturbations at temperatures as high as 600 C during laboratory characterization, and subsequently evaluated in a combustor rig operated under various engine conditions to extract the frequencies that are associated with thermoacoustic instabilities. One SiC sensor was placed directly in the flow stream of the combustor rig while a benchmark commercial water-cooled piezoceramic dynamic pressure transducer was co-located axially but kept some distance away from the hot flow stream. In the combustor rig test, the SiC sensor detected thermoacoustic instabilities across a range of engine operating conditions, amplitude magnitude as low as 0.5 psi at 585 C, in good agreement with the benchmark piezoceramic sensor. The SiC sensor experienced low signal to noise ratio at higher temperature, primarily due to the fact that it was a static sensor with low sensitivity.

  12. Developing a High Thermal Conductivity Fuel with Silicon Carbide Additives

    Energy Technology Data Exchange (ETDEWEB)

    baney, Ronald; Tulenko, James

    2012-11-20

    The objective of this research is to increase the thermal conductivity of uranium oxide (UO{sub 2}) without significantly impacting its neutronic properties. The concept is to incorporate another high thermal conductivity material, silicon carbide (SiC), in the form of whiskers or from nanoparticles of SiC and a SiC polymeric precursor into UO{sub 2}. This is expected to form a percolation pathway lattice for conductive heat transfer out of the fuel pellet. The thermal conductivity of SiC would control the overall fuel pellet thermal conductivity. The challenge is to show the effectiveness of a low temperature sintering process, because of a UO{sub 2}-SiC reaction at 1,377°C, a temperature far below the normal sintering temperature. Researchers will study three strategies to overcome the processing difficulties associated with pore clogging and the chemical reaction of SiC and UO{sub 2} at temperatures above 1,300°C:

  13. Burnout syndrome indices in Greek intensive care nursing personnel.

    Science.gov (United States)

    Karanikola, Maria N K; Papathanassoglou, Elizabeth D E; Mpouzika, Meropi; Lemonidou, Chrysoula

    2012-01-01

    Burnout symptoms in Greek intensive care unit (ICU) nurses have not been explored adequately. The aim of this descriptive, correlational study was to investigate the prevalence and intensity of burnout symptoms in Greek ICU nursing personnel and any potential associations with professional satisfaction, as well as with demographic, educational, and vocational characteristics. Findings showed that the overall burnout level reported by Greek ICU nursing personnel was at a moderate to high degree. The most pronounced symptom of burnout was depersonalization, whereas emotional exhaustion was found to be a strong predictor of job satisfaction. This is a factor connected with the nurses' intention to quit the job. It appears that work factors have a more powerful influence over the development of burnout in comparison to personality traits.

  14. Biomimetic and plasmonic hybrid light trapping for highly efficient ultrathin crystalline silicon solar cells.

    Science.gov (United States)

    Zhang, Y; Jia, B; Gu, M

    2016-03-21

    Designing effective light-trapping structures for the insufficiently absorbed long-wavelength light in ultrathin silicon solar cells represents a key challenge to achieve low cost and highly efficient solar cells. We propose a hybrid structure based on the biomimetic silicon moth-eye structure combined with Ag nanoparticles to achieve advanced light trapping in 2 μm thick crystalline silicon solar cells approaching the Yablonovitch limit. By synergistically using the Mie resonances of the silicon moth-eye structure and the plasmonic resonances of the Ag nanoparticles, the integrated absorption enhancement achieved across the usable solar spectrum is 69% compared with the cells with the conventional light trapping design. This is significantly larger than both the silicon moth-eye structure (58%) and Ag nanoparticle (41%) individual light trapping. The generated photocurrent in the 2 μm thick silicon layer is as large as 33.4 mA/cm2, which is equivalent to that generated by a 30 μm single-pass absorption in the silicon. The research paves the way for designing highly efficient light trapping structures in ultrathin silicon solar cells.

  15. The relationship between burnout and coping in adult and young offender center correctional officers: an exploratory investigation.

    Science.gov (United States)

    Gould, Drew D; Watson, Shelley L; Price, Stephanie R; Valliant, Paul M

    2013-02-01

    High levels of occupational stress and burnout are costly for correctional services and their employees. Correctional officers report high levels of burnout, absenteeism, turnover, and poor physical health. The purpose of this study was to investigate the prevalence of burnout and the coping mechanisms used to buffer the effects of burnout within correctional centers. In the current study, 208 correctional officers from adult and young offender centers completed an online survey measuring burnout and coping strategies. Results from the Maslach Burnout Inventory-Human Services Survey (MBI-HSS) and the Brief Coping Orientation to Problems Experienced (COPE) Scale indicated that even though correctional center officers mostly used adaptive coping strategies, they still reported high levels of burnout. The results of this study suggest that there are variables other than coping strategies, such as gender and length of experience, that lead to the level of burnout as observed in correctional officers.

  16. Effects of Non-Guidance Activities, Supervision, and Student-to-Counselor Ratios on School Counselor Burnout

    Science.gov (United States)

    Moyer, Michael

    2011-01-01

    School counselors, like all mental health professionals are at high risk for burnout. High caseloads, job role ambiguity, and lack of supervision increase their propensity for burnout. Three areas were selected for study in this article due to their potential impact on burnout: supervision, student-to-counselor-ratios, and non-guidance related…

  17. Perfectionism and burnout in women professional golfers.

    Science.gov (United States)

    Kang, Kyoung D; Hannon, James C; Harveson, Andrew; Lee, Jea W; Nam, Jea J; Han, Doug H

    2016-09-01

    Perfectionism and burnout have been thought to affect performance in sports. The aim of current study was to analyze differences between members of the Korean Ladies Professional Association (KLPGA) and non-KLPGA golfers as they relate to perfectionism, burnout and commitment as well as analyze the relationship between the same psychological factors and golf score during a 3-day professional golf tournament. Participants were 245 LPGA athletes and 233 non-LPGA athletes, all of whom were members of the Korean Golf Association. Participants were assessed using Multidimensional Perfectionism Scale, Athletes Burnout Questionnaires, Expansion of Sports Commitment Model and State-Trait Anxiety Inventory-Y. Perfectionism (t=48.47, PSport devaluation of burnout (t=3.84, Pcorrelated with total perfectionism (r=0.58, P=0.001), total burnout (r=0.50, P=0.008), and state anxiety (r=0.50, P=0.0049) (spearman correlation). Findings suggest that golfers seeking to attain high levels of performance must consider the importance of the mental aspect of the game of golf, and find ways to minimize stress and perfectionist strivings.

  18. Appraisals, burnout and outcomes in informal caregiving.

    Science.gov (United States)

    Lee, Haejung; Singh, Jagdip

    2010-03-01

    This study draws from the resource depletion and conservation theories to develop a process model of informal caregiving. The model includes the burnout as a key mediator of the relationship between benefit/threat appraisals and critical outcomes including perceived physical health, depression and life satisfaction. A self-report questionnaire was utilized to collect relevant data from 137 informal caregivers of older adults. The proposed model and hypotheses were evaluated with the Structural Equation Modeling method using the software EQS. The relatively high reported levels of emotional exhaustion and reduced personal accomplishment established the relevance of the burnout construct for informal caregivers. In addition, the test of the proposed model provides support for the hypothesis that burnout is an important mediator in the appraisal process model of informal caregiving. However, while burnout effectively mediates the influence of threat appraisals, its role in mediating the effect of benefit appraisals is mixed. The proposed model and results highlight the significance and potential for utilizing a process approach for understanding the link between appraisals and outcomes for informal caregivers. More importantly, the proposed model suggests that attention must be paid toward burnout tendencies to reveal fruitful intervention directions for researchers and practitioners to enhance the positive outcomes of informal caregivers, and maintain their psychological and physical well-being. Copyright © 2010 Korean Society of Nursing Science. Published by . All rights reserved.

  19. The burnout syndrome on health care professionals

    Directory of Open Access Journals (Sweden)

    Maria Polikandrioti

    2007-01-01

    Full Text Available Burnout syndrome is referred to the experience of exhaustion and diminished interest, that is manifested by the professionals usually in the work context. Health care proffesionals are often at high risk of burnout syndrome and job dissatisfaction. Burn-out syndrome consists a serious multidimensional phenomenon, because it can lead the professionals of health to psychosomatic problems, work-associated withdrawal behaviour and a lower quality of care. The aim of this review was to study the burn out syndrome of health care professionals. The method of this study included bibliography research from both the review and the research international literature, as well as to Greece and was referred to the "burn out syndrome". Results: Most studies focus on the role of work environment of health care professionals, as the main factor for the development of burn out syndrome, in combination with other factors such as personality, critically ill patients, and organizational structure and staff relationships. Furthermore, the results of this study showed the need for referral to an expert, who deals with emotional problems triggered by the daily contacts with patients and the staff nurse, in order to control the professional stress. Conclusively: Early recognition of burnout phenomenon contributes to better professional behaviour and better health care quality for patients. Health care professionals need knowledge and education about how to beat burnout syndrome.

  20. Small signal modeling of high electron mobility transistors on silicon and silicon carbide substrate with consideration of substrate loss mechanism

    Science.gov (United States)

    Sahoo, A. K.; Subramani, N. K.; Nallatamby, J. C.; Sylvain, L.; Loyez, C.; Quere, R.; Medjdoub, F.

    2016-01-01

    In this paper, we present a comparative study on small-signal modeling of AlN/GaN/AlGaN double hetero-structure high electron mobility transistors (HEMTs) grown on silicon (Si) and silicon carbide (SiC) substrate. The traditional small signal equivalent circuit model is modified to take into account the transmission loss mechanism of coplanar waveguide (CPW) line which cannot be neglected at high frequencies. CPWs and HEMTs-on-AlN/GaN/AlGaN epitaxial layers are fabricated on both the Si and SiC substrates. S-parameter measurements at room temperature are performed over the frequency range from 0.5 GHz to 40 GHz. Transmission loss of CPW lines are modeled with a distributed transmission line (TL) network and an equivalent circuit model is included in the small-signal transistor model topology. Measurements and simulations are compared and found to be in good agreement.

  1. Athlete burnout: review and recommendations.

    Science.gov (United States)

    Gustafsson, Henrik; DeFreese, J D; Madigan, Daniel J

    2017-08-01

    Over the last two decades, growing concerns regarding the negative implications of athlete burnout have spurred empirical research on the topic. In their citation network analysis of the burnout literature, Gustafsson et al. (2014), cited well over 100 publications on the syndrome. Despite considerable investigation into athlete burnout, there remain a number of unresolved questions and issues. Four main aims guide the current review. First, we highlight various models of athlete burnout. Second, we discuss the measurement of athlete burnout. Third, we describe the symptoms, antecedents, and consequences of athlete burnout with a focus on social perceptions and perfectionism. Finally, we provide suggestions for the prevention and treatment of athlete burnout via an illustration of links between theory and practice. It is our hope that this review can stimulate future research in order to help athletes avoid burnout and other severe forms of training maladaptation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. [Organizational climate and burnout syndrome].

    Science.gov (United States)

    Lubrańska, Anna

    2011-01-01

    The paper addresses the issue of organizational climate and burnout syndrome. It has been assumed that burnout syndrome is dependent on work climate (organizational climate), therefore, two concepts were analyzed: by D. Kolb (organizational climate) and by Ch. Maslach (burnout syndrome). The research involved 239 persons (122 woman, 117 men), aged 21-66. In the study Maslach Burnout Inventory (MBI) and Inventory of Organizational Climate were used. The results of statistical methods (correlation analysis, one-variable analysis of variance and regression analysis) evidenced a strong relationship between organizational climate and burnout dimension. As depicted by the results, there are important differences in the level of burnout between the study participants who work in different types of organizational climate. The results of the statistical analyses indicate that the organizational climate determines burnout syndrome. Therefore, creating supportive conditions at the workplace might reduce the risk of burnout.

  3. High-performance fused indium gallium arsenide/silicon photodiode

    Science.gov (United States)

    Kang, Yimin

    Modern long haul, high bit rate fiber-optic communication systems demand photodetectors with high sensitivity. Avalanche photodiodes (APDs) exhibit superior sensitivity performance than other types of photodetectors by virtual of its internal gain mechanism. This dissertation work further advances the APD performance by applying a novel materials integration technique. It is the first successful demonstration of wafer fused InGaAs/Si APDs with low dark current and low noise. APDs generally adopt separate absorption and multiplication (SAM) structure, which allows independent optimization of materials properties in two distinct regions. While the absorption material needs to have high absorption coefficient in the target wavelength range to achieve high quantum efficiency, it is desirable for the multiplication material to have large discrepancy between its electron and hole ionization coefficients to reduce noise. According to these criteria, InGaAs and Si are the ideal materials combination. Wafer fusion is the enabling technique that makes this theoretical ideal an experimental possibility. APDs fabricated on the fused InGaAs/Si wafer with mesa structure exhibit low dark current and low noise. Special device fabrication techniques and high quality wafer fusion reduce dark current to nano ampere level at unity gain, comparable to state-of-the-art commercial III/V APDs. The small excess noise is attributed to the large difference in ionization coefficients between electrons and holes in silicon. Detailed layer structure designs are developed specifically for fused InGaAs/Si APDs based on principles similar to those used in traditional InGaAs/InP APDs. An accurate yet straightforward technique for device structural parameters extraction is also proposed. The extracted results from the fabricated APDs agree with device design parameters. This agreement also confirms that the fusion interface has negligible effect on electric field distributions for devices fabricated

  4. High-frequency and high-quality silicon carbide optomechanical microresonators

    OpenAIRE

    Xiyuan Lu; Lee, Jonathan Y.; Qiang Lin

    2015-01-01

    Silicon carbide (SiC) exhibits excellent material properties attractive for broad applications. We demonstrate the first SiC optomechanical microresonators that integrate high mechanical frequency, high mechanical quality, and high optical quality into a single device. The radial-breathing mechanical mode has a mechanical frequency up to 1.69 GHz with a mechanical Q around 5500 in atmosphere, which corresponds to a mechanical f-Q product as high as 9.47x10^12 Hz. The strong optomechanical cou...

  5. Fabrication of low temperature cofired ceramic (LTCC) chip couplers for high frequencies : I. Effect of binder burnout process on the formation of electrode line

    Energy Technology Data Exchange (ETDEWEB)

    Cho, N.T.; Shim, K.B.; Lee, S.W. [Hanyang University, Seoul (Korea); Koo, K.D. [K-Cera Inc., Yongin (Korea)

    1999-06-01

    In the fabrication of ceramic chip couplers for high frequency applications such as the mobile communication equipment, the formation of electrode lines and Ag diffusion were investigated with heat treatment conditions for removing organic binders. The deformation and densification of the electrode line greatly depended on the binder burnout process due to the overlapped temperature zone near 400{sup o} C of the binder dissociation and the solid phase sintering of the silver electrode. Ag ions were diffused into the glass ceramic substrate. The Ag diffusion was led by the glassy phase containing Pb ions rather than by the crystalline phase containing Ca ions. The fact suggests that the Ag diffusion could be controlled by managing the composition of the glass ceramic substrate. 9 refs., 10 figs., 1 tab.

  6. Synthesis and Characterization of Mesoporous Silicon Oxynitride MCM-41 with High Nitrogen Content

    Institute of Scientific and Technical Information of China (English)

    ZHANG Cunman; XU Zheng; LIU Qian

    2005-01-01

    Mesoporous silicon oxynitrides MCM-41 were synthesized successfully. The resulting materials not only have high nitrogen contents and good structural characteristics of MCM-41 (high surface area, narrow pore size distribution and good order), but also are amorphous. The composition and structure of the materials were investigated by CNH element analysis, XPS, Si MAS NMR, XRD, HRTEM and N2 sorption, respectively. Mesoporous silicon oxynitrides MCM-41 with a high nitrogen content are still non-crystal (amorphous).

  7. Burnout syndrome among university teachers

    OpenAIRE

    ŘEHÁKOVÁ, Soňa

    2013-01-01

    This thesis deals with burnout syndrome among university teachers. The theoretical part consists of three main parts and focuses on definition of the burnout syndrome, its characteristics and causes. The second part deals with burnout syndrome, particularly among teachers and the third one describes the ways of prevention. The practical part aims to measure the susceptibility of stress and burnout among teachers at the Pedagogical Faculty in Pilsen and in České Budějovice. A questionnaire Inv...

  8. Burnout and health care utilization.

    Science.gov (United States)

    Jackson, C N; Manning, M R

    1995-01-01

    This study explores the relationship between burnout and health care utilization of 238 employed adults. Burnout was measured by the Maslach Burnout Inventory and health care utilization by insurance company records regarding these employees' health care costs and number of times they accessed health care services over a one year period. ANOVAs were conducted using Golembiewski and Munzenrider's approach to define the burnout phase. Significant differences in health care costs were found.

  9. Burnout syndrome among university teachers

    OpenAIRE

    2013-01-01

    This thesis deals with burnout syndrome among university teachers. The theoretical part consists of three main parts and focuses on definition of the burnout syndrome, its characteristics and causes. The second part deals with burnout syndrome, particularly among teachers and the third one describes the ways of prevention. The practical part aims to measure the susceptibility of stress and burnout among teachers at the Pedagogical Faculty in Pilsen and in České Budějovice. A questionnaire Inv...

  10. High impact ionization rate in silicon by sub-picosecond THz electric field pulses (Conference Presentation)

    DEFF Research Database (Denmark)

    Tarekegne, Abebe Tilahun; Iwaszczuk, Krzysztof; Hirori, Hideki

    2017-01-01

    Summary form only given. Metallic antenna arrays fabricated on high resistivity silicon are used to localize and enhance the incident THz field resulting in high electric field pulses with peak electric field strength reaching several MV/cm on the silicon surface near the antenna tips. In such high...... electric field strengths high density of carriers are generated in silicon through impact ionization process. The high density of generated carriers induces a change of refractive index in silicon. By measuring the change of reflectivity of tightly focused 800 nm light, the local density of free carriers...... near the antenna tips is measured. Using the NIR probing technique, we observed that the density of carriers increases by over 8 orders of magnitude in a time duration of approximately 500 fs with an incident THz pulse of peak electric field strength 700 kV/cm. This shows that a single impact...

  11. The Copenhagen Burnout Inventory: A new tool for the assessment of burnout

    DEFF Research Database (Denmark)

    Kristensen, Tage S.; Borritz, Marianne; Villadsen, Ebbe

    2005-01-01

    Burnout; CBI; Copenhagen Burnout Inventory; exhaustion;fatigue; human service work; psychosocial work environment; PUMA study; questionnaire validity......Burnout; CBI; Copenhagen Burnout Inventory; exhaustion;fatigue; human service work; psychosocial work environment; PUMA study; questionnaire validity...

  12. The effects of exercise program on burnout and metabolic syndrome components in banking and insurance workers.

    Science.gov (United States)

    Tsai, Han Hui; Yeh, Ching Ying; Su, Chien Tien; Chen, Chiou Jong; Peng, Shu Mei; Chen, Ruey Yu

    2013-01-01

    To explore the effectiveness of exercise program for banking and insurance workers and clarify the association between exercise, burnout, and metabolic syndrome components. In the process of the study, a practicable worksite exercise program was developed for bank and insurance enterprises. A three-month (12-wk) exercise course was conducted, and its benefits evaluated. Levels of burnout and metabolic syndrome components were analyzed after exercise intervention. After intervention, the indicators of burnout and metabolic syndrome components were significantly improved in both low and high intensity groups, and the improvement were expressed in reduction of waist circumference, systolic blood pressure, person burnout and work-related burnout. A dose-response of burnouts and metabolic syndrome components with exercise intensity are shown (psyndrome components were independently associated with burnout and exercise intensity in the crude model. After adjustment for potential confounders, waist circumference and systolic blood pressure differences showed significant associations with exercise intensity (pburnouts and metabolic syndrome components.

  13. Association between Sick Leave Prescribing Practices and Physician Burnout and Empathy.

    Directory of Open Access Journals (Sweden)

    Oriol Yuguero Torres

    Full Text Available To investigate the association between sick leave prescription and physician burnout and empathy in a primary care health district in Lleida, Spain.This descriptive study included 108 primary care doctors from 22 primary care centers in Lleida in 2014 (183,600 patients. Burnout was measured with the Maslach Burnout Inventory and empathy with the Jefferson Scale of Physician Empathy. The reliability of the instruments was measured by calculating Cronbach's alpha and normal distribution was analyzed using the Kolmogorov-Smirnov-Lilliefors and χ2 tests. Burnout and empathy scores were analyzed by age, sex, and place of work (urban vs rural. Sick leave data were obtained from the Catalan Health Institute.High empathy was significantly associated with low burnout. Neither empathy nor burnout were significantly associated with sick leave prescription.Sick leave prescription by physicians is not associated with physicians' empathy or burnout and may mostly depend on prescribing guidelines.

  14. Burnout among Dutch medical residents

    NARCIS (Netherlands)

    Prins, J.T.; Hoekstra-Weebers, J.E.; Van De Wiel, H.B.; Gazendam-Donofrio, S.M.; Sprangers, F.; Jaspers, F.C.; van der Heijden, F.M.

    2007-01-01

    We examined levels of burnout and relationships between burnout, gender, age, years in training, and medical specialty in 158 medical residents working at the University Medical Center Groningen, the Netherlands. Thirteen percent of the residents met the criteria for burnout, with the highest percen

  15. Teacher Burnout in North Dakota

    Science.gov (United States)

    Mowers, Erin N.

    2010-01-01

    The purpose of this mixed study dissertation was to determine if teachers in North Dakota public schools show signs of teacher burnout and the extent to which NCLB is a major stress factor. The research questions were: To what extent are teachers experiencing symptoms of burnout? What are the factors of burnout? The research hypothesis was: The…

  16. Burnout among Dutch medical residents

    NARCIS (Netherlands)

    Prins, J.T.; Hoekstra-Weebers, J.E.; Van De Wiel, H.B.; Gazendam-Donofrio, S.M.; Sprangers, F.; Jaspers, F.C.; van der Heijden, F.M.

    2007-01-01

    We examined levels of burnout and relationships between burnout, gender, age, years in training, and medical specialty in 158 medical residents working at the University Medical Center Groningen, the Netherlands. Thirteen percent of the residents met the criteria for burnout, with the highest percen

  17. Life Stress and Academic Burnout

    Science.gov (United States)

    Lin, Shu-Hui; Huang, Yun-Chen

    2014-01-01

    Stress has been shown to negatively affect learning. Academic burnout is a significant problem associated with poor academic performance. Although there has been increased attention on these two issues, literature on the relationship between students' life stress and burnout is relatively limited. This study surveys academic burnout and life…

  18. Burnout among Elementary School Principals

    Science.gov (United States)

    Combs, Julie; Edmonson, Stacey L.; Jackson, Sherion H.

    2009-01-01

    As the understanding of burnout continues to be refined, studies that examine school principals and burnout will be helpful to those who provide support to school leaders and are concerned about principal attrition and pending shortages. The purpose of this study was to examine the relationship between burnout and gender, age, and years experience…

  19. Organizational Communication and Burnout Symptoms

    NARCIS (Netherlands)

    Hoeven, ter Claartje L.; Jong, de Menno D.T.; Peper, Bram

    2006-01-01

    Job burnout is a psychological response to work stress. Many studies have been conducted measuring burnout and its causes and consequences. The research into causes of burnout brings up various communication-related constructs, but the relationships with feedback employees receive and communication

  20. Life Stress and Academic Burnout

    Science.gov (United States)

    Lin, Shu-Hui; Huang, Yun-Chen

    2014-01-01

    Stress has been shown to negatively affect learning. Academic burnout is a significant problem associated with poor academic performance. Although there has been increased attention on these two issues, literature on the relationship between students' life stress and burnout is relatively limited. This study surveys academic burnout and life…

  1. Life Stress and Academic Burnout

    Science.gov (United States)

    Lin, Shu-Hui; Huang, Yun-Chen

    2014-01-01

    Stress has been shown to negatively affect learning. Academic burnout is a significant problem associated with poor academic performance. Although there has been increased attention on these two issues, literature on the relationship between students' life stress and burnout is relatively limited. This study surveys academic burnout and life…

  2. Burnout among Dutch medical residents

    NARCIS (Netherlands)

    Prins, J.T.; Hoekstra-Weebers, J.E.; Van De Wiel, H.B.; Gazendam-Donofrio, S.M.; Sprangers, F.; Jaspers, F.C.; van der Heijden, F.M.

    2007-01-01

    We examined levels of burnout and relationships between burnout, gender, age, years in training, and medical specialty in 158 medical residents working at the University Medical Center Groningen, the Netherlands. Thirteen percent of the residents met the criteria for burnout, with the highest

  3. Burnout contagion among general practitioners.

    NARCIS (Netherlands)

    Bakker, A.B.; Schaufeli, W.B.; Sixma, H.J.; Bosveld, W.

    2001-01-01

    This study used a representative sample of 507 general practitioners (GPs) to test the hypothesis that burnout is contagious. Following a two-dimensional conceptualization of burnout, it is assumed that burnout is comprised of emotional exhaustion and negative attitudes (i.e., depersonalization and

  4. Stable passivations for high-efficiency silicon solar cells

    Science.gov (United States)

    Gruenbaum, P. E.; Gan, J. Y.; King, R. R.; Swanson, R. M.

    Initial designs of single-crystal silicon point-contact solar cells have shown a degradation in their efficiency after being exposed to concentrated sunlight. The main mechanism appears to be an increase in recombination centers at the Si/SiO2 interface due to ultraviolet light photoinjecting electrons from the silicon conduction band into the silicon dioxide that passivates the cell's front surface. Trichloroethane, texturization, and aluminum during the forming gas anneal all contribute to the instability of the interface. A reasonably good resistance to UV light can be obtained by putting a phosphorus diffusion at the surface and can be improved further by stripping off the deposited oxide after the diffusion and regrowing a dry thermal oxide. A second technique, which utilizes ultrathin oxides and thin polysilicon films and can yield stable point-contact solar cells that are more efficient at higher concentrations, is also described.

  5. High quality 3D shapes by silicon anodization

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Alexey; Kovacs, Andras; Mescheder, Ulrich [Institute for Applied Research and Faculty of Computer and Electrical Engineering, Hochschule Furtwangen University, Robert-Gerwig-Platz 1, 78120 Furtwangen (Germany)

    2011-06-15

    In this paper some process considerations and optimizations of anodization for three-dimensional (3D)-structuring of silicon are discussed. For the shape controlling of etched form different approaches, such as frontside masking design, local backside doping and surface pre-structuring are presented. Influences of the opening size and etch depth on the shape of the etching form are investigated. The surface quality of the resulting 3D structures is critically dependent on the specific process parameters and process flow. Best surface quality was obtained for electropolishing in 7 wt.% hydrofluoric acid (HF) at applied current densities of 100-300 mA/cm{sup 2}. Application of 3D silicon forms for injection moulding is demonstrated and further implementations of the process for optical and fluidic devices are discussed. 3D silicon shapes fabricated using anodization process with local backside doping design. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Risk factors for burnout among caregivers working in nursing homes.

    Science.gov (United States)

    Kandelman, Nadia; Mazars, Thierry; Levy, Antonin

    2017-05-25

    (i) To assess the level of burnout in nursing home caregivers within a unique healthcare network in France and (ii) to evaluate potential risk factors in this population. Burnout syndrome occurs frequently among nursing home caregivers and has strong detrimental effects on the quality of health care for residents. We used an observational survey to study burnout in nursing home caregivers. The survey was used to quantify burnout level (Maslach Burnout Inventory) and potential risk factors and was implemented from October 2013-April 2014. A logistic regression was used to explore the association between burnout and its risk factors. Three hundred and sixty questionnaires were delivered to caregivers in 14 nursing homes within a unique healthcare network. The response rate was 37% (132/360), and 124/132 (94%) surveys were analysed. Caregiver burnout rate was 40% (49/124). Median age was 41 years (range, 20-70) and most caregivers were female. The most common profession (n = 54; 44%) was nurse caregiver and 90% (n = 112) had an antecedent of bullying by a resident. Risk factors identified were as follows: the presence of institutional protocols (death announcement [OR: 3.7] and pain assessment [OR: 2.8]), working in a profit-making establishment (OR: 2.6) and the antecedent of bullying by a resident (OR: 6.2). Factors most negatively associated with burnout included: practising pastimes (OR: 0.4) and working as a nurse (OR: 0.3). The only significant risk factor in the multivariate analysis was the antecedent of bullying by a resident (OR: 5.3). Several specific risk factors for burnout in nursing home caregivers were identified. In high-risk populations of healthcare professionals, screening and management of risk factors is crucial for preventing burnout. © 2017 John Wiley & Sons Ltd.

  7. [Burnout in Tunisian medical residents: About 149 cases].

    Science.gov (United States)

    Ben Zid, A; Homri, W; Ben Romdhane, I; Bram, N; Labbane, R

    2017-09-01

    Burnout is a professional psychological chronic stress-induced syndrome defined by three dimensions: emotional exhaustion, depersonalization, and low personal accomplishment. This syndrome concerns all professions but especially healthcare staff. Numerous studies have attempted to document the impact of work activities on the doctor's mental health. According to the literature, junior doctors are more vulnerable to develop this syndrome. Are to determine the prevalence of severe burnout among residents of different specialties: anesthesiology, general surgery, emergency medicine, psychiatry, basic sciences. The secondary end points are to analyze risk factors, causes and consequences associated with burnout. A cross-sectional study conducted among medical residents working in hospitals located in the governorates of Tunis. Three instruments were used: an anonymous self-administered questionnaire, Maslach Burnout Inventory (MBI) to assess burnout, and Abstract Beck Depression Inventory to evaluate the intensity of depression. Severe burnout was defined as a severely high level of both emotional exhaustion and depersonalization associated with a severely low level of personal accomplishment. A total of 149 participants (response rate=76.8%) participated in the survey. Among participants, 17.14% (n=26) had a severe burnout. The emergency medicine residents had the highest rate of emotional exhaustion and depersonalization and severe depression. Overall, resident respondents, 31% (n=46), had moderate to severe depression. Among stress factors, those significantly correlated to burnout were: lack of hobbies (Pburnout were: Antecedents of specialty change (P=0.017) and desire for a specialty change (Pburnout was not found. Medical residents in all specialties are at risk of burnout. Nevertheless, this study revealed that some specialties are more exhausting, which is consistent with the results reported in the literature. Moreover, it is shown that several stress factors

  8. Intermittent Very High Frequency Plasma Deposition on Microcrystalline Silicon Solar Cells Enabling High Conversion Efficiency

    Directory of Open Access Journals (Sweden)

    Mitsuoki Hishida

    2016-01-01

    Full Text Available Stopping the plasma-enhanced chemical vapor deposition (PECVD once and maintaining the film in a vacuum for 30 s were performed. This was done several times during the formation of a film of i-layer microcrystalline silicon (μc-Si:H used in thin-film silicon tandem solar cells. This process aimed to reduce defect regions which occur due to collision with neighboring grains as the film becomes thicker. As a result, high crystallinity (Xc of μc-Si:H was obtained. Eventually, a solar cell using this process improved the conversion efficiency by 1.3% (0.14 points, compared with a normal-condition cell. In this paper, we propose an easy method to improve the conversion efficiency with PECVD.

  9. The Silicon Valley Eco System. High-energetic in many ways; Het Silicon Valley Eco Systeem: hoogenergetisch in vele opzichten

    Energy Technology Data Exchange (ETDEWEB)

    Van den Heuvel, J.

    2012-04-15

    The highly commended Silicon Valley Eco System is bubbling with energy with regard to the subjects that are focused upon, including sustainable energy, or the widely available expertise that is needed for the developments, good ideas, capital and optimism, fed by frequent examples of extraordinarily successful companies. The sheer endlessness of network opportunities joins all these elements frequently. This article addresses several noteworthy interactions in the field of sustainable energy over the last period. [Dutch] Het veel geroemde Silicon Valley eco systeem bruist van energie in de vorm van de onderwerpen waar men zich op richt, waaronder duurzame energie, of de ruim aanwezige expertise die nodig is voor de ontwikkelingen, goede ideeen, kapitaal, en optimisme, gevoed door regelmatige voorbeelden van buitensporig succesvolle bedrijven. De schier oneindige netwerkmogelijkheden brengen al deze elementen met grote regelmaat bij elkaar. In dit artikel volgen enkele vermeldenswaardige interacties op het vlak van duurzame energie uit de afgelopen periode.

  10. Burnout among psychiatrists in the Veterans Health Administration

    Directory of Open Access Journals (Sweden)

    Hector A. Garcia

    2015-12-01

    Full Text Available Research suggests that mental health workers are at high risk for burnout, and that burnout can increase staff turnover and reduce quality of care. The Veterans Administration (VA employs over 3000 psychiatrists across the United States, but little is known about burnout in this population. This study was conducted to examine predictors of burnout and intent to leave the VA among a national sample of VA psychiatrists. Participants (N = 125 responded to an anonymous online survey. Regression analyses were used to examine relationships between workplace variables, patient characteristics, and burnout as measured by the Maslach Burnout Inventory-General Survey – which includes sub-scales for cynicism, exhaustion, and professional efficacy – as well as intent to leave the VA. Based on established cut-off scores, 90% of the sample reported high cynicism, 86% reported high exhaustion, and 74% reported high professional efficacy. High cynicism predicted the intent to leave the VA (p = .004. Not feeling part of a coherent team predicted greater cynicism (p = .01, and patient characteristics such as suspected malingering showed a positive trend with cynicism (p = .05. Workplace characteristics such as unfair treatment by supervisors (p = .03 and insufficient resources (p = .001 predicted greater exhaustion. The current findings suggest that burnout is prevalent in the VA psychiatry workforce. Specific administrative measures to reduce burnout may have potential to improve the emotional health of that workforce and ensure high quality of care for the veteran population it serves. The size of both the VA psychiatry workforce and patient population underscores the importance of greater understanding of burnout as it occurs in the VA.

  11. Thermal Transport in Silicon Nanowires at High Temperature up to 700 K.

    Science.gov (United States)

    Lee, Jaeho; Lee, Woochul; Lim, Jongwoo; Yu, Yi; Kong, Qiao; Urban, Jeffrey J; Yang, Peidong

    2016-07-13

    Thermal transport in silicon nanowires has captured the attention of scientists for understanding phonon transport at the nanoscale, and the thermoelectric figure-of-merit (ZT) reported in rough nanowires has inspired engineers to develop cost-effective waste heat recovery systems. Thermoelectric generators composed of silicon target high-temperature applications due to improved efficiency beyond 550 K. However, there have been no studies of thermal transport in silicon nanowires beyond room temperature. High-temperature measurements also enable studies of unanswered questions regarding the impact of surface boundaries and varying mode contributions as the highest vibrational modes are activated (Debye temperature of silicon is 645 K). Here, we develop a technique to investigate thermal transport in nanowires up to 700 K. Our thermal conductivity measurements on smooth silicon nanowires show the classical diameter dependence from 40 to 120 nm. In conjunction with Boltzmann transport equation, we also probe an increasing contribution of high-frequency phonons (optical phonons) in smooth silicon nanowires as the diameter decreases and the temperature increases. Thermal conductivity of rough silicon nanowires is significantly reduced throughout the temperature range, demonstrating a potential for efficient thermoelectric generation (e.g., ZT = 1 at 700 K).

  12. Professional burnout syndrome among correctional facility officers.

    Science.gov (United States)

    Harizanova, Stanislava N; Tarnovska, Tanya H

    2013-01-01

    Correctional facilities present unique work places--the employees there work in tough, demanding and hazardous working conditions, in real life-threatening environment, subjected to physical and mental fatigue, risk of infectious diseases, work in shifts, with inadequate pay, etc. The aim of this study was to find the prevalence and level of burnout syndrome among employees working in the District Prison of the town of Plovdiv. The study included all employees that had direct contact with the inmates in the prison. We recruited 106 employees that participated in the study anonymously and voluntarily. The main instrument we used was the questionnaire designed according to the methods developed by V. Boiko, which allows identification of professional burnout syndrome in its three phases with four symptoms in each of the phases. We found a high prevalence of burnout syndrome among the staff in the District Prison in Plovdiv (74.53%). All three phases of burnout were found to have a high prevalence rate--the stress phase: 48.11%, the resistance phase: 66.98%, the exhaustion phase: 41.51%. The rank in the service hierarchy was found to be a predictor in the stress phase, B = 0.701, p = 0.048, Exp(B) = 2.106, 95%CI [1.00; 4.04]. The single officers (83.33% of the divorced and 55.56% of the single employees) and those of the staff that were more highly educated (78.72%) had elevated levels of burnout syndrome, and these manifested during the first 5 years of their service in the prison (77.78%). In Bulgaria at present the burnout syndrome has not been studied among employees working in correctional facilities. We found a high prevalence of the syndrome among the employees of the District Prison - Plovdiv. The younger, the single and the more educated employees had greater levels of burnout syndrome, which manifest during the first 5 years of their service. The results suggest that there is a need to develop and implement effective strategies to reduce and prevent

  13. Compassion Fatigue, Burnout, and Neonatal Abstinence Syndrome.

    Science.gov (United States)

    Sweigart, Erin

    2017-01-01

    NICU nurses have seen a dramatic increase in cases of neonatal abstinence syndrome (NAS). The care needs of infants with NAS are highly demanding and can lead to feelings of frustration and emotional exhaustion among NICU nurses. Although studies have examined the experiences of nurses caring for NAS patients, none have specifically addressed the risk for compassion fatigue and burnout. Nurses need practical strategies to reduce their risk for compassion fatigue and burnout when caring for these patients. Improved education and implementation of self-care measures can help nurses more effectively manage stress and positively impact care of these infants and their families.

  14. [Asthenic syndrome in patients with burnout syndrome].

    Science.gov (United States)

    Chutko, L S; Surushkina, S Iu; Rozhkova, A V; Nikishena, I S; Iakovenko, E A

    2013-01-01

    The authors present the results of a survey of 103 patients aged 25 to 45 years with burnout syndrom. The results showed that most patients with the syndrome of burnout have clinical manifestations of asthenia, varying degrees of severity. According to psychological and psychophysiological examination in this group of patients were found attention and memory dysfunction. This study evaluated the efficacy of memoplant in the treatment of this pathology. The high efficiency of memoplant (improvement in 69.7% of cases) was detected, confirmed by the data of the clinical, psychological and neuropsychological research.

  15. Development of burnout over time and the causal order of the three dimensions of burnout among male and female GPs. A three-wave panel study

    Directory of Open Access Journals (Sweden)

    Twellaar Mascha

    2011-04-01

    Full Text Available Abstract Background A good understanding of the aetiology and development of burnout facilitates its early recognition, prevention and treatment. Since the prevalence and onset of this health problem is thought to differ between men and women, sex must be taken into account. This study aims to assess the prevalence and development of burnout among General Practitioners (GPs. In this population the prevalence of burnout is high. Methods We performed a three-wave longitudinal study (2002, 2004, 2006 in a random sample of Dutch GPs. Data were collected by means of self-report questionnaires including the Maslach Burnout Inventory. Our final sample consisted of 212 GPs of which 128 were male. Data were analyzed by means of SPSS and LISREL. Results Results indicate that about 20% of the GPs is clinically burned out (but still working. For both sexes, burnout decreased after the first wave, but increased again after the second wave. The prevalence of depersonalization is higher among men. With regard to the process of burnout we found that for men burnout is triggered by depersonalization and by emotional exhaustion for women. Conclusions As regards the developmental process of burnout, we found evidence for the fact that the aetiological process of burnout, that is the causal order of the three burnout dimensions, differs between men and women. These sex differences should be taken into account in vocational training and policy development, especially since general practice is feminizing rapidly.

  16. Mindfulness, burnout, and effects on performance evaluations in internal medicine residents.

    Science.gov (United States)

    Braun, Sarah E; Auerbach, Stephen M; Rybarczyk, Bruce; Lee, Bennett; Call, Stephanie

    2017-01-01

    Burnout has been documented at high levels in medical residents with negative effects on performance. Some dispositional qualities, like mindfulness, may protect against burnout. The purpose of the present study was to assess burnout prevalence among internal medicine residents at a single institution, examine the relationship between mindfulness and burnout, and provide preliminary findings on the relation between burnout and performance evaluations in internal medicine residents. Residents (n = 38) completed validated measures of burnout at three time points separated by 2 months and a validated measure of dispositional mindfulness at baseline. Program director end-of-year performance evaluations were also obtained on 22 milestones used to evaluate internal medicine resident performance; notably, these milestones have not yet been validated for research purposes; therefore, the investigation here is exploratory. Overall, 71.1% (n = 27) of the residents met criteria for burnout during the study. Lower scores on the "acting with awareness" facet of dispositional mindfulness significantly predicted meeting burnout criteria χ(2)(5) = 11.88, p = 0.04. Lastly, meeting burnout criteria significantly predicted performance on three of the performance milestones, with positive effects on milestones from the "system-based practices" and "professionalism" domains and negative effects on a milestone from the "patient care" domain. Burnout rates were high in this sample of internal medicine residents and rates were consistent with other reports of burnout during medical residency. Dispositional mindfulness was supported as a protective factor against burnout. Importantly, results from the exploratory investigation of the relationship between burnout and resident evaluations suggested that burnout may improve performance on some domains of resident evaluations while compromising performance on other domains. Implications and directions for future research are discussed.

  17. Burnout em residentes de enfermagem Burnout en residentes de enfermería Burnout in nursing residents

    Directory of Open Access Journals (Sweden)

    Gianfábio Pimentel Franco

    2011-03-01

    Adultos y Pediátrica. Edad y especialidad se correlacionaron positivamente con Incompetencia/falta de Realización Profesional. Se identificó a un Residente de Enfermería con alteración en las tres sub-escalas del Maslach Burnout Inventory, caracterizándoselo como portador de Síndrome de Burnout. Los Residentes de Enfermería poseen perfiles de sufrimiento. Conocer tales factores puede minimizar los transtornos de salud de dichos trabajadores.Nursing residents may experience physical and emotional exhaustion from the daily life of attending the Program. The aim of this study was to determine the Burnout incidence among Nursing Residents. An investigative, descriptive, analytical, longitudinal-prospective study was conducted with 16 Residents over two years. The Maslach Burnout Inventory was used, translated and validated for Brazil, as well as a sociodemographic/occupational data tool. Of all residents, 17.2% showed high rates in Emotional Exhaustion and Depersonalization; 18.8% showed impaired commitment in Personal Accomplishment, 75% of which belonged to specialty areas, such as Emergency Nursing, Adult and Pediatric Intensive Care. Age and specialty area were positively correlated with Personal Accomplishment. One of the Residents was identified with changes in three subscales of the Maslach Burnout Inventory, thus characterized as a Burnout Syndrome patient. Nursing Residents have profiles of disease. Knowing these factors can minimize health risks of these workers.

  18. The prevalence of burnout syndrome in Polish anaesthesiologists.

    Science.gov (United States)

    Misiołek, Aleksandra; Gorczyca, Piotr; Misiołek, Hanna; Gierlotka, Zbigniew

    2014-01-01

    Burnout syndrome is a psychological response to chronic work-related stress characterized by low enthusiasm towards the job, high psychological exhaustion, indolence and guilt. Being a medical doctor, both in Poland and in other countries, is one of the most stressful occupations and anaesthesiology is considered one of the most stressful specializations, which justify carrying out of the study on Polish anaesthesiologists. The aim of the study was to determine the prevalence of burnout syndrome in Polish anaesthesiologists Non-randomized cross-sectional study was carried out and data were gathered through a self-administrated questionnaire. The sample consisted of 373 Polish anaesthesiologists, 57.6% were women and 42.4% were men. A 66% response rate was achieved. The Burnout Syndrome was measured by the Spanish Burnout Inventory. The prevalence burnout risk was almost 70%. The percentage of participants who indicated very high levels of burnout was 18%; 5.9% of whom fell into profile 2 considered to be clinical. The instrument applied was reliable with Cronbach's alphas exceeding 0.70. The sample is characterized by high burnout risk with 5.9% of clinical cases. Participation in prevention programs is recommended.

  19. Work environment, job satisfaction, stress and burnout among haemodialysis nurses.

    Science.gov (United States)

    Hayes, Bronwyn; Douglas, Clint; Bonner, Ann

    2015-07-01

    To examine the relationships among nurse and work characteristics, job satisfaction, stress, burnout and the work environment of haemodialysis nurses. Haemodialysis nursing is characterised by frequent and intense contact with patients in a complex and intense environment. A cross-sectional online survey of 417 haemodialysis nurses that included nurse and work characteristics, the Brisbane Practice Environment Measure, Index of Work Satisfaction, Nursing Stress Scale and the Maslach Burnout Inventory. Haemodialysis nurses reported an acceptable level of job satisfaction and perceived their work environment positively, although high levels of burnout were found. Nurses who were older and had worked in haemodialysis the longest had higher satisfaction levels, experienced less stress and lower levels of burnout than younger nurses. The in-centre type of haemodialysis unit had greater levels of stress and burnout than home training units. Greater satisfaction with the work environment was strongly correlated with job satisfaction, lower job stress and emotional exhaustion. Haemodialysis nurses experienced high levels of burnout even though their work environment was favourable and they had acceptable levels of job satisfaction. Targeted strategies are required to retain and avoid burnout in younger and less experienced nurses in this highly specialised field of nursing. © 2013 John Wiley & Sons Ltd.

  20. Silicon solar cell monitors high temperature furnace operation

    Science.gov (United States)

    Zellner, G. J.

    1968-01-01

    Silicon solar cell, attached to each viewpoint, monitors that incandescent emission from the hot interior of a furnace without interfering with the test assembly or optical pyrometry during the test. This technique can provide continuous indication of hot spots or provide warning of excessive temperatures in cooler regions.

  1. Burn-Out among Israeli Arab School Principals as a Function of Professional Identity and Interpersonal Relationships with Teachers.

    Science.gov (United States)

    Lya, Kremer-Hayon; Faraj, Hani; Wubbels, Theo

    2002-01-01

    Study of burnout among Israeli Arab school principals as a function of professional identity and interpersonal relationships with teachers. Finds, for example, a low extent of burnout, a high extent of professional identity, and a negative correlation between burnout and the positive elements of interpersonal relationships. (Contains 30…

  2. Burnout in occupational therapists.

    Science.gov (United States)

    Rogers, J C; Dodson, S C

    1988-12-01

    Burnout is a job-related condition involving feelings of emotional exhaustion, depersonalization, and reduced personal accomplishment. The Maslach Burnout Inventory (Maslach & Jackson, 1981a) is the instrument most widely used to measure job-related stress in human service professions, such as occupational therapy. This study explored the application of the Maslach Burnout Inventory for use with occupational therapists. The subjects were 99 registered occupational therapists residing in the southeastern United States. Mean scores lower than the aggregate occupational norms provided by the test's authors on the Emotional Exhaustion and Depersonalization subscales supported the need to develop specific norms for occupational therapists. Results of this study indicate that use of the aggregate norms would underestimate the level of experienced burnout. Correlational analyses delineated significant relationships between age and Emotional Exhaustion and Depersonalization, education and Emotional Exhaustion and Depersonalization, years of work as an occupational therapist and Depersonalization and Personal Accomplishment, years in the present position and Personal Accomplishment (intensity only), hours of direct patient contact and Emotional Exhaustion (intensity only), and hours of direct patient contact and Depersonalization (frequency only). These correlates of burnout furnish clues for understanding the development of work-related stress in occupational therapists.

  3. Hospital restructuring and burnout.

    Science.gov (United States)

    Greenglass, Esther R; Burke, Ronald J

    2002-01-01

    Increasingly, organizations are experiencing changes as a result of extensive downsizing, restructuring, and merging. In Canada, government-sponsored medicine has been affected as hospitals have merged or closed, reducing essential medical services and resulting in extensive job loss for hospital workers, particularly nurses. Hospital restructuring has also resulted in greater stress and job insecurity in nurses. The escalation of stressors has created burnout in nurses. This study examines predictors of burnout in nurses experiencing hospital restructuring using the MBI-General Survey which yields scores on three scales: Emotional exhaustion, Cynicism, and Professional efficacy. Multiple regressions were conducted where each burnout scale was the criterion and stressors (e.g., amount of work, use of generic workers to do nurses' work), restructuring effects, social support, and individual resources (e.g., control coping, self-efficacy, prior organizational commitment) were predictors. There were differences in the amount of variance accounted for in the burnout components by stressors and resources. Stressors contributed most to emotional exhaustion and least to professional efficacy. Individual resources were more likely to contribute to professional efficacy and least to emotional exhaustion. Stressors and resources accounted for approximately equal amounts of variance in cynicism. Three conclusions were drawn. First, present findings parallel others by showing that individual coping patterns contribute to professional efficacy. Second, emotional exhaustion was found to be the prototype of stress. Third, prior organizational commitment, self-efficacy, and control coping resulted in lower burnout.

  4. High deposition rate processes for the fabrication of microcrystalline silicon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Michard, S. [Institute of Energy and Climate Research 5 - Photovoltaik, Forschungszentrum Jülich, 52425 Jülich (Germany); Meier, M., E-mail: ma.meier@fz-juelich.de [Institute of Energy and Climate Research 5 - Photovoltaik, Forschungszentrum Jülich, 52425 Jülich (Germany); Grootoonk, B.; Astakhov, O.; Gordijn, A.; Finger, F. [Institute of Energy and Climate Research 5 - Photovoltaik, Forschungszentrum Jülich, 52425 Jülich (Germany)

    2013-05-15

    The increase of deposition rate of microcrystalline silicon absorber layers is an essential point for cost reduction in the mass production of thin-film silicon solar cells. In this work we explored a broad range of plasma enhanced chemical vapor deposition (PECVD) parameters in order to increase the deposition rate of intrinsic microcrystalline silicon layers keeping the industrial relevant material quality standards. We combined plasma excitation frequencies in the VHF band with the high pressure high power depletion regime using new deposition facilities and achieved deposition rates as high as 2.8 nm/s. The material quality evaluated from photosensitivity and electron spin resonance measurements is similar to standard microcrystalline silicon deposited at low growth rates. The influence of the deposition power and the deposition pressure on the electrical and structural film properties was investigated.

  5. Synthesis of Silicon Nitride and Silicon Carbide Nanocomposites through High Energy Milling of Waste Silica Fume for Structural Applications

    Science.gov (United States)

    Suri, Jyothi

    Nanocomposites have been widely used in a multitude of applications in electronics and structural components because of their improved mechanical, electrical, and magnetic properties. Silicon nitride/Silicon carbide (Si 3N4/SiC) nanocomposites have been studied intensively for low and high temperature structural applications, such as turbine and automobile engine components, ball bearings, turbochargers, as well as energy applications due to their superior wear resistance, high temperature strength, high oxidation resistance and good creep resistance. Silica fume is the waste material produced during the manufacture of silicon and ferro-silicon alloys, and contains 94 to 97 wt.% SiO2. In the present dissertation, the feasibility of using waste silica fume as the raw material was investigated to synthesize (I) advanced nanocomposites of Si3N4/SiC, and (2) porous silicon carbide (SiC) for membrane applications. The processing approach used to convert the waste material to advanced ceramic materials was based on a novel process called, integrated mechanical and thermal activation process (IMTA) process. In the first part of the dissertation, the effect of parameters such as carbothermic nitridation and reduction temperature and the graphite concentration in the starting silica fume plus graphite mixture, were explored to synthesize nanocomposite powders with tailored amounts of Si3N4 and SiC phases. An effective way to synthesize carbon-free Si3N 4/SiC composite powders was studied to provide a clear pathway and fundamental understanding of the reaction mechanisms. Si3N4/SiC nanocomposite powders were then sintered using two different approaches, based on liquid phase sintering and spark plasma sintering processes, with Al 2O3 and Y2O3 as the sintering aids. The nanocomposites were investigated for their densification behavior, microstructure, and mechanical properties. Si3N4/SiC nanocomposites thus obtained were found to possess superior mechanical properties at much

  6. Burnout and career satisfaction among US oncologists.

    Science.gov (United States)

    Shanafelt, Tait D; Gradishar, William J; Kosty, Michael; Satele, Daniel; Chew, Helen; Horn, Leora; Clark, Ben; Hanley, Amy E; Chu, Quyen; Pippen, John; Sloan, Jeff; Raymond, Marilyn

    2014-03-01

    To evaluate the personal and professional characteristics associated with career satisfaction and burnout among US oncologists. Between October 2012 and March 2013, the American Society of Clinical Oncology conducted a survey of US oncologists evaluating burnout and career satisfaction. The survey sample included equal numbers of men and women and represented all career stages. Of 2,998 oncologists contacted, 1,490 (49.7%) returned surveys (median age of respondents, 52 years; 49.6% women). Among the 1,117 oncologists (37.3% of overall sample) who completed full-length surveys, 377 (33.8%) were in academic practice (AP) and 482 (43.2%) in private practice (PP), with the remainder in other settings. Oncologists worked an average of 57.6 hours per week (AP, 58.6 hours per week; PP, 62.9 hours per week) and saw a mean of 52 outpatients per week. Overall, 484 oncologists (44.7%) were burned out on the emotional exhaustion and/or depersonalization domain of Maslach Burnout Inventory (AP, 45.9%; PP, 50.5%; P = .18). Hours per week devoted to direct patient care was the dominant professional predictor of burnout for both PP and AP oncologists on univariable and multivariable analyses. Although a majority of oncologists were satisfied with their career (82.5%) and specialty (80.4%) choices, both measures of career satisfaction were lower for those in PP relative to AP (all P career satisfaction is high among US oncologists, albeit lower for those in PP relative to AP. Burnout rates among oncologists seem similar to those described in recent studies of US physicians in general. Those oncologists who devote the greatest amount of their professional time to patient care seem to be at greatest risk for burnout.

  7. Ultra-high-speed wavelength conversion in a silicon photonic chip

    DEFF Research Database (Denmark)

    Hu, Hao; Ji, Hua; Galili, Michael

    2011-01-01

    We have successfully demonstrated all-optical wavelength conversion of a 640-Gbit/s line-rate return-to-zero differential phase-shift keying (RZ-DPSK) signal based on low-power four wave mixing (FWM) in a silicon photonic chip with a switching energy of only ~110 fJ/bit. The waveguide dispersion...... of the silicon nanowire is nano-engineered to optimize phase matching for FWM and the switching power used for the signal processing is low enough to reduce nonlinear absorption from twophoton- absorption (TPA). These results demonstrate that high-speed wavelength conversion is achievable in silicon chips...

  8. Fully-depleted, back-illuminated charge-coupled devices fabricated on high-resistivity silicon

    Energy Technology Data Exchange (ETDEWEB)

    Holland, Stephen E.; Groom, Donald E.; Palaio, Nick P.; Stover, Richard J.; Wei, Mingzhi

    2002-03-28

    Charge-coupled devices (CCD's) have been fabricated on high-resistivity silicon. The resistivity, on the order of 10,000 {Omega}-cm, allows for depletion depths of several hundred microns. Fully-depleted, back-illuminated operation is achieved by the application of a bias voltage to a ohmic contact on the wafer back side consisting of a thin in-situ doped polycrystalline silicon layer capped by indium tin oxide and silicon dioxide. This thin contact allows for good short wavelength response, while the relatively large depleted thickness results in good near-infrared response.

  9. Fabrication of novel AFM probe with high-aspect-ratio ultra-sharp three-face silicon nitride tips

    NARCIS (Netherlands)

    Vermeer, Rolf; Berenschot, Erwin; Sarajlic, Edin; Tas, Niels; Jansen, Henri

    2014-01-01

    In this paper we present the wafer-scale fabrication of molded AFM probes with high aspect ratio ultra-sharp three-plane silicon nitride tips. Using (111) silicon wafers a dedicated process is developed to fabricate molds in the silicon wafer that have a flat triangular bottom surface enclosed by th

  10. Evolution of arsenic in high fluence plasma immersion ion implanted silicon : Behavior of the as-implanted surface

    NARCIS (Netherlands)

    Vishwanath, V.; Demenev, E.; Giubertoni, D.; Vanzetti, L.; Koh, A. L.; Steinhauser, G.; Pepponi, G.; Bersani, M.; Meirer, F.; Foad, M. A.

    2015-01-01

    High fluence (>1015 ions/cm2) low-energy (3 + on (1 0 0) silicon was investigated, with the focus on stability and retention of the dopant. At this dose, a thin (∼3 nm) amorphous layer forms at the surface, which contains about 45% arsenic (As) in a silicon and oxygen matrix. The presence of silicon

  11. Evolution of arsenic in high fluence plasma immersion ion implanted silicon : Behavior of the as-implanted surface

    NARCIS (Netherlands)

    Vishwanath, V.; Demenev, E.; Giubertoni, D.; Vanzetti, L.; Koh, A. L.; Steinhauser, G.; Pepponi, G.; Bersani, M.; Meirer, F.; Foad, M. A.

    2015-01-01

    High fluence (>1015 ions/cm2) low-energy (3 + on (1 0 0) silicon was investigated, with the focus on stability and retention of the dopant. At this dose, a thin (∼3 nm) amorphous layer forms at the surface, which contains about 45% arsenic (As) in a silicon and oxygen matrix. The presence of silicon

  12. Longitudinal assessment of depression, stress, and burnout in medical students

    Science.gov (United States)

    Goel, Akhil D.; Akarte, Sulbha V.; Agrawal, Sumita P.; Yadav, Vikas

    2016-01-01

    Background: Medical students can and do suffer from mental disorders is a concept yet to get wide acceptance. There are few studies comprehensively evaluating depression, stress, and burnout in medical students, especially in a longitudinal way in India. The current study aims to assess the impact of medical education on the development of psychological morbidities and the role of personality. Materials and Methods: First-year medical students of a leading medical college of India were enrolled on admission and given anonymized, validated, self-administered questionnaires assessing depression, stress, burnout, and personality. This was repeated at the end of 1st year. Data were analyzed independently as questionnaires were anonymized. Results: We found that 1st year of medical college showed a significantly increasing depression (P burnout did not increase significantly. However, only disengagement dimension of burnout increased significantly. Personalities with weak capacity to adjust had a significant positive correlation with depression (r = 0.277, P burnout did not correlate with any of the personality dimensions. Conclusion: Right from the 1st year of medical education students perceive high-stress levels and have a high risk of depression. Burnout starts to creep in at least in the form of disengagement. This study provides a sound groundwork for planning interventions to reduce student's mental morbidity and avoid burnout. PMID:27695226

  13. Nurses’ Burnout in Oncology Hospital Critical Care Unit

    Directory of Open Access Journals (Sweden)

    Yeliz İrem Tunçel

    2014-08-01

    Full Text Available Objective: Burnout is common in intensive care units (ICU because of high demands and difficult working conditions. The aim of this study was to analyse nurses’ burnout in our oncology ICU and to determine which factors are associated with. Material and Method: The study was carried out in Ankara Oncology Hospital ICU. A self- reporting questionnaire in an envelope was used for the evaluation of burnout (Turkish- language version of Maslach Burnout Inventory and depression (Beck Depression Scale. Results: From a total of 37 ICU nurses, 35 participated in the study (%94,5 response rate. High levels of emotional exhaustion in 82% and depersonalization in 51,4% of nurses was determined. Personal accomplishment was higher at 80%. Mild to moderate emotional state and mild anxiety was revealed. Years in profession,finding salary insufficient, finding the profession in its proper, choosing the profession of his own accord, work environment satisfaction and finding the social activity adequate were associated with burnout (p≤0.05. Conclusion: In our study, intensive care unit nurses’ burnout scores were found to be higher. Burnout was rare in nurses that choose the profession of his own accord, find the nursing profession in its proper, and social activity adequate and are satisfied with the work environment. Therefore, we believe that attention should be given to individual needs and preferences in the selection of ICU staff.

  14. [Prevalence of burnout among obstetrics and gynecology residents].

    Science.gov (United States)

    Rua, C; Body, G; Marret, H; Ouldamer, L

    2015-01-01

    Prevalence assessment of burnout among obstetrics and gynecology residents and predisposing factors. Multicentric cross-sectional survey based on a questionnaire sent by email to the residents including demographics data and Maslach Burnout Inventory. Mean burnout scores were 19.67±10.19 for emotional exhaustion, 33.94±5.01 for personal accomplishment and 8.72±6.10 for depersonalization, corresponding to a moderate burnout for each category. High scores of burnout were seen on 19.45 % of residents for emotional exhaustion, 33.33 % for depersonalization and 11.11 % for personal accomplishment. 36.11 % of residents showed evidence of high burnout in emotional exhaustion or depersonalization, and 5.55 % in the three dimensions. The number of semesters is correlated with depersonalization (P=0.01). There is a strong personal accomplishment among obstetrics and gynecology residents; however, burnout and emotional exhaustion remains a reality during obstetrics and gynecology residency. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  15. Health behaviors and personality in burnout: a third dimension

    Directory of Open Access Journals (Sweden)

    Osama M. Mustafa

    2015-09-01

    Full Text Available The high prevalence of burnout among healthcare professionals warrants a thorough examination aimed at improving the current understanding of its predictors and preventive measures. Cecil et al. have underscored the alarming prevalence of burnout among medical students and assessed its association with demographic, lifestyle, and behavioral factors. Of interest, health behaviors were found to be predictive of burnout. The study suggests certain behaviors (such as high physical activity to be protective, and thus, calls for their establishment early in college life to prevent the development of this professionally-disabling mental state. Although the adoption of advisable health behaviors may independently reduce the risk of burnout, recognition of the existence and influence of closely related factors allows for an enhanced understanding and a greater precision for any conclusions to be made. Personality, through deductive and inductive reasoning, is likely to exert significant influence on both the student's behavior and his/her susceptibility to burnout. Thus, with personality representing – in and of itself – a principal model for prediction of burnout risk, controlling for personality traits when addressing health behaviors’ influence per se on burnout is essential.

  16. Burnout in critical care nurses: a literature review.

    Science.gov (United States)

    Epp, Kirstin

    2012-01-01

    Burnout and its development in critical care nurses is a concept that has received extensive study, yet remains a problem in Canada and around the world. Critical care nurses are particularly vulnerable to developing burnout due to the chronic occupational stressors they are exposed to, including high patient acuity, high levels of responsibility, working with advanced technology, caring for families in crisis, and involved in morally distressing situations, particularly prolonging life unnecessarily. The purpose of this article is to explore how the chronic stressors that critical care nurses are exposed to contribute to the development of burnout, and strategies for burnout prevention. A review of the literature between the years 2007 and 2012 was conducted and included the search terms burnout, moral distress, compassion fatigue, intensive care, critical care, and nursing. The search was limited to the adult population, English language, and Western cultures. The results revealed that nurse managers play a crucial role in preventing burnout by creating a supportive work environment for critical care nurses. Strategies for nurse managers to accomplish this include being accessible to critical care nurses, fostering collegial relationships among the different disciplines, and making a counsellor or grief team available to facilitate debriefing after stressful situations, such as a death. In addition, critical care nurses can help prevent burnout by being a support system for each other and implementing self-care strategies.

  17. Burnout After Patient Death: Challenges for Direct Care Workers.

    Science.gov (United States)

    Boerner, Kathrin; Gleason, Hayley; Jopp, Daniela S

    2017-09-01

    Direct care workers in long-term care can develop close relationships with their patients and subsequently experience significant grief after patient death. Consequences of this experience for employment outcomes have received little attention. To investigate staff, institutional, patient, and grief factors as predictors of burnout dimensions among direct care workers who had experienced recent patient death; determine which specific aspects of these factors are of particular importance; and establish grief as an independent predictor of burnout dimensions. Participants were 140 certified nursing assistants and 80 homecare workers who recently experienced patient death. Data collection involved comprehensive semistructured in-person interviews. Standardized assessments and structured questions addressed staff, patient, and institutional characteristics, grief symptoms and grief avoidance, as well as burnout dimensions (depersonalization, emotional exhaustion, and personal accomplishment). Hierarchical regressions revealed that grief factors accounted for unique variance in depersonalization, over and above staff, patient, and institutional factors. Supervisor support and caregiving benefits were consistently associated with higher levels on burnout dimensions. In contrast, coworker support was associated with a higher likelihood of depersonalization and emotional exhaustion. Findings suggest that grief over patient death plays an overlooked role in direct care worker burnout. High supervisor support and caregiving benefits may have protective effects with respect to burnout, whereas high coworker support may constitute a reflection of burnout. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

  18. 职高生心理韧性、学业自我效能感与学习倦怠的关系%Relationship between resilience,academic self - efficacy and learning burnout of vocational high school students

    Institute of Scientific and Technical Information of China (English)

    武帅; 谢一鸣; 吴晓凡; 杨绍清

    2016-01-01

    Objective To understand the characteristics of learning burnout in vocational high school students and the relationship between resilience ,academic self - efficacy and learning burnout . Methods 676 students in 3 vocational high schools in Tangshan city were measured as subjects by u‐sing teenager resilience scales ,academic elf - efficacy question - Naire and the junior middle school burnout questionnaires .Results The learning burnout score of vocational high school students was low ,and there were significant gender differences in the emotional dimension of depletion(t = 4 .543 ,P< 0 .01) ,the estrangement between teachers and students(t = 5 .035 ,P < 0 .01) and the burnout scores(t= 4 .663 ,P < 0 .01) ,boys were significantly higher than girls ;There was a negative correlation between resilience and academic burnout of students(r = - 0 .497 ,P < 0 .01) ;Vocational high school students ac‐ademic self - efficacy and learning burnout existed significant negative correlation(r = - 0 .568 ,P <0 .01) .Conclusion The learning burnout level is low ,and there is significant gender difference ;Their re‐silience is lower ,the academic self - efficacy is lower ,their learning burnout is higher .%①目的探讨职高生学习倦怠的状况及其与心理韧性、学业自我效能感的关系。②方法采用中学生学习倦怠问卷、青少年心理韧性量表和学业自我效能感问卷对唐山市3所职教中心676名职业高中生实施测试。③结果职高生的学习倦怠得分较低,并且在性别方面存在显著差异。男生在情绪耗竭( t =4.543,P <0.01)、师生疏离( t =5.035,P<0.01)维度上的得分及倦怠总分( t =4.663,P <0.01)显著高于女生;职高学生的心理韧性水平与其学业倦怠存在显著负相关( r =-0.497,P <0.01)。职高生学业自我效能感与学习倦怠存在显著负相关( r =-0.568,P <0.01)。④结论职高生的

  19. The prevalence of burnout among oncology professionals: oncologists are at risk of developing burnout.

    Science.gov (United States)

    Eelen, S; Bauwens, S; Baillon, C; Distelmans, W; Jacobs, E; Verzelen, A

    2014-12-01

    International research shows that oncology staff suffers more from burnout than other healthcare professionals. Burnout is common among oncologists. The prevalence of emotional exhaustion, depersonalization, and low personal accomplishment appears to be significantly higher among physicians. Detecting burnout is highly relevant, because it affects the personal well-being and quality of life of the healthcare professional. A national study on the prevalence of burnout in oncology was never conducted in Flanders (Dutch-speaking part of Belgium). The Cédric Hèle institute spread anonymous questionnaires among 923 healthcare workers in oncology (physicians, social workers, psychologists, nurses, and specialist-nurses) in Flanders. The questionnaire consisted of two parts. The first part contained questions concerning demographic and job features. The second part included the Dutch version of the Maslach Burnout Inventory. Five hundred and fifty subjects participated in the survey (response rate of 59.5%). Of the medical oncologists, 51.2% suffered from emotional exhaustion, 31.8% from depersonalization, and 6.8% from a lack of personal accomplishment. Multivariate analysis of variance suggested a significantly elevated level of emotional exhaustion and depersonalization in oncologists compared with other professionals. Logistic regression indicated that the following variables have predictive value on risk of burnout: gender, profession, and combining work in a university hospital with work in a private hospital. The CHi research showed a significantly increased level of burnout-components in professionals working in oncology, especially in medical oncologists. These results should have an impact on the daily clinic of oncology, and could be guidance for further research. Copyright © 2014 John Wiley & Sons, Ltd.

  20. [Burnout syndrome among health staff].

    Science.gov (United States)

    Curiel-García, José Angel; Rodríguez-Morán, Martha; Guerrero-Romero, Fernando

    2006-01-01

    To determine the prevalence of burnout syndrome components among the medical and nursing staff of the second care level hospitals of the Instituto Mexicano del Seguro Social and Instituto de Seguridad Social al Servicio de los Trabajadores del Estado from Durango, Mexico. A cross-sectional comparative study was carried out among 73 physicians and 100 nurses randomly selected from both hospitals. The prevalence of burnout syndrome components was established by the Maslash Burnout Inventory, which determines the presence of physical/emotional exhaustion, depersonalization, and labor performance. In addition, sociodemographic and labor information was collected. Prevalence was calculated with a reliability interval of 95% (CI 95%). 73 physicians and 100 nurses enrolled, corresponding to 22.8% and 14.5% of such personnel working in both institutions. Among the IMSS and ISSSTE workers respectively, the prevalence of depersonalization was 43.2% (34.4-52.9) and 14.5% (6.8-25.8), whereas the prevalence of physical/emotional exhaustion was 41.4% (32.7-51.1) and 19.4% (10.4-31.4). Pre-valence of labor performance was higher among the personnel of Instituto Mexicano del Seguro Social: 99.1% (95.1-100) versus 96.8% (88.8-100). Severe depersonalization (p = 0.004), but not emotional exhaustion (p = 0.09) nor labor performance (p = 0.06) was significantly higher among personnel working at the Instituto Mexicano del Seguro Social. Prevalence of depersonalization and physical/emotional exhaustion was higher among physicians and nurses of the Instituto Mexicano del Seguro Social; nonetheless, their labor performance was high. Our finding suggests that personnel working at the Instituto Mexicano del Seguro Social make a greater effort to maintain the high labor performance that medical care requires.

  1. Workload, burnout, and medical mistakes among physicians in China: A cross-sectional study.

    Science.gov (United States)

    Wen, Jin; Cheng, Yongzhong; Hu, Xiuying; Yuan, Ping; Hao, Tianyou; Shi, Yingkang

    2016-02-01

    The purpose of this study is to determine the prevalence of burnout among different grade hospitals and to examine if a relation exists between burnout and medical mistakes. A multi-center cross-sectional survey was conducted. Physicians were interviewed in hospitals from 10 provinces in China. Burnout was measured using the Chinese version of the Maslach Burnout Inventory-General Survey. Overall, 1,537 physicians were included in this study. Of these, 76.9% reported some burnout symptoms or serious burnout symptoms and 54.8% reported committing medical mistakes during the last year. 39.6%, 50.0%, and 59.5% of the respondents in primary, secondary, and tertiary hospitals respectively reported having made mistakes over the course of the previous year. Multivariate analysis demonstrated that being female was protective against medical mistakes (OR = 0.72, 95% CI: 0.58-0.89), whereas physician-reported 60 or more work hours per week (OR = 1.65, 95% CI: 1.22-2.22), and physicians who reported serious burnout (OR = 2.28, 95% CI: 1.63-3.17) were independently associated with higher incidence of medical mistakes. In conclusion, Chinese physicians reported high workloads, high rates of burnout and high medical mistakes. Physicians in tertiary hospitals were especially overworked and suffered the most serious burnout. Longer work hours per week, and burnout were the independent risk factors for medical mistakes.

  2. Mentoring to Help Prevent Physician Burnout.

    Science.gov (United States)

    Herring, Malcolm; Forbes Kaufman, Rachel; Bogue, Richard

    2016-07-01

    The importance of a person's spirit and eternal destiny are eclipsed in American medi- cine. The most alarming effect of this eclipse is that the prevalence of burnout among physicians is high (about 46 percent) and growing.' It is alarming because trends that deplete the physician's spirit tragically impair the physician's capacity as a healer and as one who renews the spirit.

  3. Research on the Fe-silicon nitride material self-producing N2 at high temperature

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The Fe-silicon nitride synthesized by flashing combustion process was studied to determine the reaction temperature between Fe and silicon nitride, the account of N2 given out in the course of the reaction, and the change of the microstructure during calcination. The results showed that at 1127.2℃ the Fe-silicon nitride self-reacts and releases N2 and under 101.3 kPa the volume of N2 given out in the course of the reaction is 20 times more than that of the starting material. N2 is produced quickly, and completes in several decade seconds. With the producing of N2, the structure of Silicon Nitride around Fe becomes loose and porous, or cracks are formed by the reaction between Fe and silicon nitride. So if it is made use of that Fe-silicon nitride self-producing N2 at the high temperature, the performance of the material on a base of Fe-silicon nitride could be greatly improved.

  4. High temperature mechanical performance of a hot isostatically pressed silicon nitride

    Energy Technology Data Exchange (ETDEWEB)

    Wereszczak, A.A.; Ferber, M.K.; Jenkins, M.G.; Lin, C.K.J. [and others

    1996-01-01

    Silicon nitride ceramics are an attractive material of choice for designers and manufacturers of advanced gas turbine engine components for many reasons. These materials typically have potentially high temperatures of usefulness (up to 1400{degrees}C), are chemically inert, have a relatively low specific gravity (important for inertial effects), and are good thermal conductors (i.e., resistant to thermal shock). In order for manufacturers to take advantage of these inherent properties of silicon nitride, the high-temperature mechanical performance of the material must first be characterized. The mechanical response of silicon nitride to static, dynamic, and cyclic conditions at elevated temperatures, along with reliable and representative data, is critical information that gas turbine engine designers and manufacturers require for the confident insertion of silicon nitride components into gas turbine engines. This final report describes the high-temperature mechanical characterization and analyses that were conducted on a candidate structural silicon nitride ceramic. The high-temperature strength, static fatigue (creep rupture), and dynamic and cyclic fatigue performance were characterized. The efforts put forth were part of Work Breakdown Structure Subelement 3.2.1, {open_quotes}Rotor Data Base Generation.{close_quotes} PY6 is comparable to other hot isostatically pressed (HIPed) silicon nitrides currently being considered for advanced gas turbine engine applications.

  5. Surface-Decorated Silicon Nanowires: A Route to High-ZT Thermoelectrics

    DEFF Research Database (Denmark)

    Markussen, Troels; Jauho, Antti-Pekka; Brandbyge, Mads

    2009-01-01

    Based on atomistic calculations of electron and phonon transport, we propose to use surface-decorated silicon nanowires for thermoelectric applications. Two examples of surface decorations are studied to illustrate the underlying ideas: nanotrees and alkyl functionalized silicon nanowires. For both...... systems we find (i) that the phonon conductance is significantly reduced compared to the electronic conductance leading to high thermoelectric figure of merit ZT, and (ii) for ultrathin wires, surface decoration leads to significantly better performance than surface disorder....

  6. High-efficient n-i-p thin-film silicon solar cells

    NARCIS (Netherlands)

    Yang, G.

    2015-01-01

    In this thesis we present results of the development of n-i-p thin-film silicon solar cells on randomly textured substrates, aiming for highly efficient micromorph solar cells (i.e., solar cells based on a μc-Si:H bottom cell and a-Si:H top cell). For the efficiency of n-i-p thin-film silicon solar

  7. A high-Tc superconductor bolometer on a silicon nitride membrane

    NARCIS (Netherlands)

    Sánchez, S.; Elwenspoek, M.C.; Gui, C.; Nivelle, de M.J.M.E.; Vries, de R.J.; Korte, de P.A.J.; Bruijn, M.P.; Wijnbergen, J.J.; Michalke, W.; Steinbeiss, E.; Heidenblut, T.; Schwierzi, B.

    1997-01-01

    In this paper we describe the design, fabrication and performance of a high-Tc GdBa2Cu3O7-δ superconductor bolometer positioned on a 2×2 mm2, 1 μm thick silicon nitride membrane. The bolometer structure has an effective area of 0.64 mm2, and was grown on a specially developed Silicon-On-Nitride laye

  8. High-efficient n-i-p thin-film silicon solar cells

    NARCIS (Netherlands)

    Yang, G.

    2015-01-01

    In this thesis we present results of the development of n-i-p thin-film silicon solar cells on randomly textured substrates, aiming for highly efficient micromorph solar cells (i.e., solar cells based on a μc-Si:H bottom cell and a-Si:H top cell). For the efficiency of n-i-p thin-film silicon solar

  9. High Temperature Oxidation and Mechanical properties of Silicon Nitride.

    Science.gov (United States)

    1980-11-30

    Rowcliffe, and R. H. Lamoreaux Prepared for: Air Force Office of Scientific Research/NE Building 410 Boiling Air Force Base, D.C. 20332 Attention: Captain...samples were examined by x-ray dif- fraction. Cristobalite and a-Si 3N4 lines were found, but there was no evidence of silicon oxynitride. In most... cristobalite is the stable form.𔃾 A large amount of evi- dence indicates that this phase transiticn was not the primary reason for the increased

  10. Perceived collective burnout: a multilevel explanation of burnout.

    Science.gov (United States)

    González-Morales, M Gloria; Peiró, José M; Rodríguez, Isabel; Bliese, Paul D

    2012-01-01

    Building up on the socially induced model of burnout and the job demands-resources model, we examine how burnout can transfer without direct contagion or close contact among employees. Based on the social information processing approach and the conservation of resources theory, we propose that perceived collective burnout emerges as an organizational-level construct (employees' shared perceptions about how burned out are their colleagues) and that it predicts individual burnout over and above indicators of demands and resources. Data were gathered during the first term and again during the last term of the academic year among 555 teachers from 100 schools. The core dimensions of burnout, exhaustion, and cynicism were measured at the individual and collective level. Random coefficient models were computed in a lagged effects design. Results showed that perceived collective burnout at Time 1 was a significant predictor of burnout at Time 2 after considering previous levels of burnout, demands (workload, teacher-student ratio, and absenteeism rates), and resources (quality of school facilities). These findings suggest that perceived collective burnout is an important characteristic of the work environment that can be a significant factor in the development of burnout.

  11. Bread board float zone experiment system for high purity silicon

    Science.gov (United States)

    Kern, E. L.; Gill, G. L., Jr.

    1982-01-01

    A breadboard float zone experimental system has been established at Westech Systems for use by NASA in the float zone experimental area. A used zoner of suitable size and flexibility was acquired and installed with the necessary utilities. Repairs, alignments and modifications were made to provide for dislocation free zoning of silicon. The zoner is capable of studying process parameters used in growing silicon in gravity and is flexible to allow trying of new features that will test concepts of zoning in microgravity. Characterizing the state of the art molten zones of a growing silicon crystal will establish the data base against which improvements of zoning in gravity or growing in microgravity can be compared. 25 mm diameter was chosen as the reference size, since growth in microgravity will be at that diameter or smaller for about the next 6 years. Dislocation free crystals were growtn in the 100 and 111 orientations, using a wide set of growth conditions. The zone shape at one set of conditions was measured, by simultaneously aluminum doping and freezing the zone, lengthwise slabbing and delineating by etching. The whole set of crystals, grown under various conditions, were slabbed, polished and striation etched, revealing the growth interface shape and the periodic and aperiodic natures of the striations.

  12. High dynamic range, hyper-terahertz detection with silicon photoconductors

    Science.gov (United States)

    Muir, A. C.; Hussain, A.; Andrews, S. R.

    2016-06-01

    The frequency response of ion implanted silicon photoconductive devices designed for coherent detection in time domain terahertz spectroscopy has been studied between 0.2 and 30 THz. Unlike devices using polar photoconductors or ones having polar substrates, which have a complicated response spectrum in the region of their reststrahlen bands, the response of silicon detectors fabricated on silicon substrates is relatively featureless. When used with amplified laser systems, the dynamic range of Si detectors is shown to be very similar to that of GaAs devices with the same geometry over a 20 THz range, superior to air-biased coherent detection (ABCD) at frequencies below ˜7 THz and comparable with both ABCD and electro-optic sampling in thin ZnTe crystals between 7 and 20 THz. Together with their ease of use and linear response in terahertz fields approaching 1 MV/cm, this suggests that Si photoconductors could be a competitive choice for sensitive detection in nonlinear hyper-terahertz spectroscopy.

  13. Moral distress and burnout in internal medicine residents

    Science.gov (United States)

    Sajjadi, Sharareh; Norena, Monica; Wong, Hubert; Dodek, Peter

    2017-01-01

    Background Residents frequently encounter situations in their workplace that may induce moral distress or burnout. The objective of this study was to measure overall and rotation-specific moral distress and burnout in medical residents, and the relationship between demographics and moral distress and burnout. Methods The revised Moral Distress Scale and the Maslach Burnout Inventory (Human Service version) were administered to Internal Medicine residents in the 2013–2014 academic year at the University of British Columbia. Results Of the 88 residents, 45 completed the surveys. Participants (mean age 30+/−3; 46% male) reported a median moral distress score (interquartile range) of 77 (50–96). Twenty-six percent of residents had considered quitting because of moral distress, 21% had a high level of burnout, and only 5% had a low level of burnout. Moral distress scores were highest during Intensive Care Unit (ICU) and Clinical Teaching Unit (CTU) rotations, and lowest during elective rotations (pburnout were associated with intention to leave the job. Conclusion Internal Medicine residents report moral distress that is greatest during ICU and CTU rotations, and is associated with burnout and intention to leave the job.

  14. The prevalence of burnout syndrome in medical students

    Directory of Open Access Journals (Sweden)

    Gilson de Cavalcante Almeida

    2016-02-01

    Full Text Available Abstract Background Burnout syndrome (BS is a set of psychological symptoms resulting from the interaction between chronic occupational stress and individual factors. These symptoms include emotional exhaustion, depersonalization and decreased professional satisfaction. BS is manifested in a variety of professions and is prevalent in contexts in which health professionals are required to interact directly with the public. Objective To determine the prevalence of BS among medical students at a university in Ceará State, Brazil. Methods Of the 517 students enrolled in their first to eighth semester in 2013, 376 (72.7% were contacted. A socio-economic evaluation questionnaire and the Maslach Burnout Inventory – Human Services Survey (MBI-HSS were administered. Statistical analysis was conducted using SPSS 20.0. Two groups – burnout/risk and non-burnout – were compared using the chi-square and likelihood ratio tests with a significance level of 5%. Variables with p < 0.20 were included in a multivariate analysis logistical regression model. Results Burnout was detected in 14.9% of the students, and 57.7% showed a risk of developing the syndrome. Logistic regressions showed an association between burnout and “have failed examinations” and “have considered abandoning the course”, p = 0.047 and p < 0.0001, respectively. Discussion Psychopedagogy should be implemented to address the high prevalence of burnout in medical students.

  15. Silicon dioxide with a silicon interfacial layer as an insulating gate for highly stable indium phosphide metal-insulator-semiconductor field effect transistors

    Science.gov (United States)

    Kapoor, V. J.; Shokrani, M.

    1991-01-01

    A novel gate insulator consisting of silicon dioxide (SiO2) with a thin silicon (Si) interfacial layer has been investigated for high-power microwave indium phosphide (InP) metal-insulator-semiconductor field effect transistors (MISFETs). The role of the silicon interfacial layer on the chemical nature of the SiO2/Si/InP interface was studied by high-resolution X-ray photoelectron spectroscopy. The results indicated that the silicon interfacial layer reacted with the native oxide at the InP surface, thus producing silicon dioxide, while reducing the native oxide which has been shown to be responsible for the instabilities in InP MISFETs. While a 1.2-V hysteresis was present in the capacitance-voltage (C-V) curve of the MIS capacitors with silicon dioxide, less than 0.1 V hysteresis was observed in the C-V curve of the capacitors with the silicon interfacial layer incorporated in the insulator. InP MISFETs fabricated with the silicon dioxide in combination with the silicon interfacial layer exhibited excellent stability with drain current drift of less than 3 percent in 10,000 sec, as compared to 15-18 percent drift in 10,000 sec for devices without the silicon interfacial layer. High-power microwave InP MISFETs with Si/SiO2 gate insulators resulted in an output power density of 1.75 W/mm gate width at 9.7 GHz, with an associated power gain of 2.5 dB and 24 percent power added efficiency.

  16. Modeling the splitting of thin silicon films from porosified crystalline silicon upon high temperature annealing in hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Ghannam, Moustafa Y.; Raheem, Yaser Abdul; Alomar, Abdul Azeez [EE Department, College of Engineering and Petroleum, Kuwait University, Safat (Kuwait); Poortmans, Jef [IMEC, Leuven (Belgium)

    2012-10-15

    The role of hydrogen in promoting thin film splitting from crystalline silicon wafers with pores or trenches during high temperature annealing is investigated. During the treatment, trenches are transformed into spherical voids that may laterally channel and split off the substrate. It is shown that the conditions necessary for hydrogen to contribute to the establishment of high stress levels around transformed voids or of pressure inside the voids are usually not satisfied. Hence promoting void coalescence by substantial void volume growth resulting from stress enhanced vacancy diffusion and/or exfoliation of separated voids are unlikely to occur. Also, there are no experimental evidence that confirms the role of hydrogen in triggering premature void collapse by Griffith fracture at relatively lower stress levels in conjunction with reduced surface energy. Therefore, it is concluded that splitting occurs during high temperature annealing only when neighboring voids are close enough to systematically coalesce. In that case, hydrogen may react at high temperature with the internal silicon surface of the voids (walls) and contribute to breaking the thin straps separating the voids which promotes channelling and film splitting (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Synthesis of high-quality mesoporous silicon particles for enhanced lithium storage performance

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chundong, E-mail: apcdwang@hust.edu.cn [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China); Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong SAR (China); Ren, Jianguo [Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong SAR (China); Chen, Hao [Department of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou (China); Zhang, Yi [School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan, 430073 (China); Ostrikov, Kostya [School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane 4000, QLD (Australia); Manufacturing Flagship, CSIRO, P. O. Box 218, Lindfield, NSW 2070 (Australia); Zhang, Wenjun [Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong SAR (China); Li, Yi, E-mail: liyi@suda.edu.cn [Department of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou (China); Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong SAR (China)

    2016-04-15

    Silicon has been considered as one of the most promising anode materials for high-capacity lithium-ion batteries (LIBs) due to its ultrahigh theoretical capacity, abundance, and environmentally benign nature. Nonetheless, the severe break during the prolonged cycling results in poor electrochemical performance, which hinders its practical application. Herein, we report the synthesis of novel mesoporous silicon particles with a facile template method by using a magnesiothermic reduction for LIBs. The obtained silicon nanoparticles are highly porous with densely porous cavities (20–40 nm) on the wall, of which it presents good crystallization. Electrochemical measurements showed that the mesoporous silicon nanoparticles delivered a high reversible specific capacity of 910 mA h g{sup −1} at a high current density of 1200 mA g{sup −1} over 50 cycles. The specific capacity at such high current density is still over twofold than that of commercial graphite anode, suggesting that the nanoporous Si architectures is suitable for high-performance Si-based anodes for lithium ion batteries in terms of capacity, cycle life, and rate capacity. - Highlights: • Silica nanotubes were prepared with a facile template method. • Novel mesoporous silicon particles were obtained by magnesiothermic reduction. • High-Performance LIBs were achieved by using mesoporous Si particle Electrodes.

  18. High efficiency photoluminescence from silicon nanocrystals prepared by plasma synthesis and organic surface passivation

    Energy Technology Data Exchange (ETDEWEB)

    Mangolini, L.; Kortshagen, U. [Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455 (United States); Jurbergs, D.; Rogojina, E. [Innovalight Inc., 3303 Octavius Drive Suite 104, Santa Clara, CA 95054 (United States)

    2006-07-01

    An efficient synthesis route for highly luminescent silicon quantum dots is presented. Silicon nanocrystals were synthesized in the gas phase using an argon-silane non-thermal plasma in a continuous flow reactor. Liquid phase surface passivation was used to improve the optical properties and avoid surface oxidation of the silicon quantum dots. Various alkenes, such as octadecene, dodecene and styrene, were covalently bonded to the plasma-produced particles, while strictly avoiding exposure of the raw powder to oxidizing agents. Stable colloidal solutions of silicon quantum dots with ensemble quantum yields between 60% and 70% were achieved. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Research on high-efficiency, single-junction, monolithic, thin-film amorphous silicon solar cells

    Science.gov (United States)

    Wiesmann, H.; Dolan, J.; Fricano, G.; Danginis, V.

    1987-02-01

    A study was undertaken of the optoelectronic properties of amorphous silicon-hydrogen thin films deposited from disilane at high deposition rates. The information derived from this study was used to fabricate amorphous silicon solar cells with efficiencies exceeding 7%. The intrinsic layer of these solar cells was deposited at 15 angstroms/second. Material properties investigated included dark conductivity, photoconductivity, minority carrier diffusion length, and density of states. The solar cells properties characterized were absolute quantum yield and simulated global AM 1.5 efficiencies. Investigations were undertaken utilizing optical and infrared spectroscopy to optimize the microstructures of the intrinsic amorphous silicon. That work was sponsored by the New York State Energy Research and Development Authority. The information was used to optimize the intrinsic layer of amorphous silicon solar cells, resulting in AM 1.5 efficiencies exceeding 7%.

  20. Preparation of highly aligned silicon oxide nanowires with stable intensive photoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Duraia, El-Shazly M., E-mail: duraia_physics@yahoo.co [Suez Canal University, Faculty of Science, Physics Department, Ismailia (Egypt); Al-Farabi Kazakh National University, Almaty (Kazakhstan); Institute of Physics and Technology, 11 Ibragimov Street, 050032 Almaty (Kazakhstan); Mansurov, Z.A. [Al-Farabi Kazakh National University, Almaty (Kazakhstan); Tokmolden, S. [Institute of Physics and Technology, 11 Ibragimov Street, 050032 Almaty (Kazakhstan); Beall, Gary W. [Texas State University-San Marcos, Department of Chemistry and Biochemistry, 601 University Dr., San Marcos, TX 78666 (United States)

    2010-02-15

    In this work we report the successful formation of highly aligned vertical silicon oxide nanowires. The source of silicon was from the substrate itself without any additional source of silicon. X-ray measurement demonstrated that our nanowires are amorphous. Photoluminescence measurements were conducted through 18 months and indicated that there is a very good intensive emission peaks near the violet regions. The FTIR measurements indicated the existence of peaks at 463, 604, 795 and a wide peak at 1111 cm{sup -1} and this can be attributed to Si-O-Si and Si-O stretching vibrations. We also report the formation of the octopus-like silicon oxide nanowires and the growth mechanism of these structures was discussed.

  1. Relationship between burnout and PTSD symptoms in firefighters: the moderating effects of a sense of calling to firefighting.

    Science.gov (United States)

    Jo, Insung; Lee, Songhee; Sung, Gyhye; Kim, Minkyoung; Lee, Sanghyuk; Park, Jooeon; Lee, Kangsoo

    2017-10-03

    Firefighting has been reported to lead to burnout and posttraumatic stress disorder (PTSD). However, burnout and PTSD symptoms may vary depending on personal characteristics, such as having a sense of calling. This study examined the role of calling in the association between burnout and PTSD symptoms. We hypothesized that burnout would be associated with more severe PTSD symptoms and calling would buffer the relationship between burnout and PTSD symptoms. The Korean version of the Maslach Burnout Inventory-General Survey, Sense of Calling Subscale of the Professionalism Scale, and the Impact of Event Scale-Revised-Korean version were used to measure burnout, calling, and PTSD symptoms. Data from 109 of 127 firefighters from Gyeonggi-do, South Korea were analyzed using hierarchical linear regression. Burnout was a significant predictor of PTSD symptoms. Furthermore, the interaction term between burnout and calling accounted for a significant variance in PTSD symptoms. Higher burnout was associated with severe PTSD symptoms, but this relationship differed by the level of calling. The increase in PTSD symptoms due to increased burnout in the high calling group was relatively higher than in the low and average calling groups. Calling, though perceived as a positive variable, can be hazardous to exhausted people. A sense of calling as part of one's job identity should not be encouraged until personal circumstances and characteristics, such burnout symptoms, are evaluated. Identifying context and variables associated with PTSD for interventions with firefighters and persons in other dangerous occupations should aid in their recovery from trauma exposure.

  2. Empathy, Burnout, Demographic Variables and their Relationships in Oncology Nurses.

    Science.gov (United States)

    Taleghani, Fariba; Ashouri, Elaheh; Saburi, Morteza

    2017-01-01

    Development of nurse-patient empathic communication in the oncology ward is of great importance for the patients to relieve their psychological stress, however, nursing care of cancer patients is accompanied with high stress and burnout. The present study aimed to define the level of empathy and its association with burnout and some demographic characteristics of oncology nurses. This descriptive/correlation study was conducted in a professional cancer treatment center in Isfahan. Through census sampling, 67 oncology nurses were selected. The data collection tools were Jefferson Scale of Nursing Empathy, Maslach Burnout Inventory, and demographic characteristics questionnaire. Mean nurses' empathy and overall burnout scores were 62.28 out of 100 and 38.8 out of 100, respectively. Score of empathy showed an inverse correlation with overall burnout score (r = -0.189, P = 0.04), depersonalization (r = -0.218, P = 0.02), and personal accomplishment (r = -0.265, P = 0.01). Multiple regression test was used to detect which dimension of burnout was a better predictor for the reduction of empathy score. Results showed that the best predictors were lack of personal accomplishment (P = 0.02), depersonalization (P = 0.04), and emotional exhaustion (P = 0.14), respectively. The most influential demographic factor on empathy was work experience (r = 0.304, P = 0.004). One-way analysis of variance showed that official staff had a higher empathy score (f = 2.39, P = 0.045) and their burnout was lower (f = 2.56, P = 0.04). Results showed a negative relationship between empathy and burnout in oncology nurses. Therefore, nursing support from managers to reduce burnout increases empathic behavior of nurses.

  3. Systematic review: Factors associated with return to work in burnout.

    Science.gov (United States)

    Kärkkäinen, R; Saaranen, T; Hiltunen, S; Ryynänen, O P; Räsänen, K

    2017-08-01

    Professional burnout predicts sick leave and even permanent withdrawal from the labour force. However, knowledge of the barriers to and facilitators of return to work (RTW) in such burnout is limited. To identify factors associated with RTW of burned-out individuals to inform occupational health care (OHC) RTW policy. A systematic search of peer-reviewed quantitative and mixed-method studies published from January 2005 to July 2016 in English and Finnish in ARTO, CINAHL (EBSCO), Medic, PsycINFO (ProQuest), PubMed, Scopus and Web of Science databases, followed by a manual search. We included studies that identify burnout with valid burnout measures and measure the degree of RTW or sick leave as outcomes. We excluded studies with heterogeneous samples without subgroup analyses of RTW in burnout cases. We included 10 studies (three experimental and seven observational) of the initial 1345 identified. The studies reported work-related factors; enhanced communication (positive association) and low control at work (negative association) and individual-related factors; male gender (positive association), covert coping (negative association), high over-commitment to work (positive association) and burnout-related factors; unimpaired sleep (positive association), duration of sick leave over 6 months (negative association) and part-time sick leave (positive association) associated with RTW in burnout. Associations between burnout rehabilitation and RTW, and the level of symptoms and cognitive impairment and RTW remained unclear. Few quantitative studies, of varied methodological quality, explore factors associated with RTW in burnout. Further research is needed to build an evidence base and develop guidelines for supportive OHC actions.

  4. Burnout syndrome in pediatric practice.

    Science.gov (United States)

    Al-Youbi, Reem A; Jan, Mohammed M

    2013-07-01

    Burnout is a common work-related syndrome consisting of emotional exhaustion, depersonalization and diminished feelings of personal accomplishment. Burnout influences the performance and efficiency of the healthcare professionals and therefore the quality of the care provided. This study aims to assess the burnout rates and potential determinants in pediatrics. A cross-sectional, descriptive study involving physicians practicing pediatrics in the Jeddah area of Saudi Arabia was conducted utilizing the Maslach Burnout Inventory in addition to questions regarding work-related and lifestyle-related factors. One hundred and thirty pediatricians (55% females) were included with age ranging between 25 and 45 years (mean: 30). Most (46%) were consultants and 54% practiced in a university based setting. Burnout scores were abnormal in 107 (82%) and in 45 (34%) the syndrome was severe. Males were more likely to reach a severe burnout category compared to females (40% vs. 31%; p=0.012). Academic pediatricians working in a university setting were much more likely to experience severe burnout compared to their counterparts working in other hospitals (50% vs. 19%; p=0.0005). Consultants were also more likely to experience severe burnout compared to residents and assistants (46% vs. 27%; p=0.03). At least one third of practicing pediatricians suffer from burnout syndrome. Specific strategies should be developed and implemented to limit and prevent professional burnout.

  5. [Burnout syndrome in general practitioners of Avila].

    Science.gov (United States)

    Frutos-Llanes, R; Jiménez-Blanco, S; Blanco-Montagut, L E

    2014-10-01

    To determine the level of burnout in general practitioners of Avila and the influence of social, occupational and health factors. A descriptive cross-sectional epidemiological study was conducted and aimed at all Primary Care medical staff of Avila during the first half of 2011, using two questionnaires: the Maslach Burnout Inventory and other sociodemographic, health and occupational variables. A response rate of 51.8% was obtained. The mean age was 48.55±8.16, and 52% were male, 77% married, 45% with tenure, 78% worked in rural centres, and, 82% performed out of hours home visits plus clinics. The prevalence of severe burn out was low (16%) in our study was low. A high prevalence (68%) of moderate/severe level of the condition was found. Being married (P=.012), do not guards (Pburnout in severe or moderate/severe burnout. A moderate level of burnout was found. Contrary to what many doctors thought, the prevalence of the condition in its severe form was low, but was high when taking the severe and moderate/severe forms together. Therefore, measures should be extended to reduce occupational stress of doctors, in order to improve working practices and professional efficiency. Copyright © 2013 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

  6. Printable nanostructured silicon solar cells for high-performance, large-area flexible photovoltaics.

    Science.gov (United States)

    Lee, Sung-Min; Biswas, Roshni; Li, Weigu; Kang, Dongseok; Chan, Lesley; Yoon, Jongseung

    2014-10-28

    Nanostructured forms of crystalline silicon represent an attractive materials building block for photovoltaics due to their potential benefits to significantly reduce the consumption of active materials, relax the requirement of materials purity for high performance, and hence achieve greatly improved levelized cost of energy. Despite successful demonstrations for their concepts over the past decade, however, the practical application of nanostructured silicon solar cells for large-scale implementation has been hampered by many existing challenges associated with the consumption of the entire wafer or expensive source materials, difficulties to precisely control materials properties and doping characteristics, or restrictions on substrate materials and scalability. Here we present a highly integrable materials platform of nanostructured silicon solar cells that can overcome these limitations. Ultrathin silicon solar microcells integrated with engineered photonic nanostructures are fabricated directly from wafer-based source materials in configurations that can lower the materials cost and can be compatible with deterministic assembly procedures to allow programmable, large-scale distribution, unlimited choices of module substrates, as well as lightweight, mechanically compliant constructions. Systematic studies on optical and electrical properties, photovoltaic performance in experiments, as well as numerical modeling elucidate important design rules for nanoscale photon management with ultrathin, nanostructured silicon solar cells and their interconnected, mechanically flexible modules, where we demonstrate 12.4% solar-to-electric energy conversion efficiency for printed ultrathin (∼ 8 μm) nanostructured silicon solar cells when configured with near-optimal designs of rear-surface nanoposts, antireflection coating, and back-surface reflector.

  7. High-frequency and high-quality silicon carbide optomechanical microresonators

    CERN Document Server

    Lu, Xiyuan; Lin, Qiang

    2015-01-01

    Silicon carbide (SiC) exhibits excellent material properties attractive for broad applications. We demonstrate the first SiC optomechanical microresonators that integrate high mechanical frequency, high mechanical quality, and high optical quality into a single device. The radial-breathing mechanical mode has a mechanical frequency up to 1.69 GHz with a mechanical Q around 5500 in atmosphere, which corresponds to a mechanical f-Q product as high as 9.47x10^12 Hz. The strong optomechanical coupling allows us to efficiently excite and probe the coherent mechanical oscillation by optical waves. The demonstrated devices, in combination with the superior thermal property, chemical inertness, and defect characteristics of SiC, show great potential for applications in metrology, sensing, and quantum photonics, particularly in harsh environments that are challenging for other device platforms.

  8. Burnout and Light Treatment

    NARCIS (Netherlands)

    Meesters, Y.; Waslander, M.

    The core symptom of the burnout syndrome is emotional exhaustion, which leads to impaired functioning on the job. Studies of sufferers of seasonal affective disorders and of healthy people show that energy levels can be improved by exposing them to bright light. It is hypothesized that energy levels

  9. Burnout and Light Treatment

    NARCIS (Netherlands)

    Meesters, Y.; Waslander, M.

    2010-01-01

    The core symptom of the burnout syndrome is emotional exhaustion, which leads to impaired functioning on the job. Studies of sufferers of seasonal affective disorders and of healthy people show that energy levels can be improved by exposing them to bright light. It is hypothesized that energy levels

  10. 'Burnout' among Dutch midwives.

    NARCIS (Netherlands)

    Bakker, R.H.C.; Groenewegen, P.P.; Jabaaij, L.; Meijer, W.; Sixma, H.; Veer, A. de

    1996-01-01

    OBJECTIVE: to determine the effect of workload on 'burnout' having considered work capacity. DESIGN: cross-sectional study. SETTING: Dutch community midwives in independent practice. PARTICIPANTS: 200 Dutch community midwives. MEASUREMENTS: three-week diary recordings, a questionnaire on practice an

  11. Female nurses' burnout symptoms: No association with the Hypothalamic-pituitary-thyroid (HPT) axis.

    Science.gov (United States)

    Guo, Yufang; Lam, Louisa; Luo, Yuanhui; Plummer, Virginia; Cross, Wendy; Li, Hui; Yin, Yizhen; Zhang, Jingping

    2017-03-01

    Across the world, hospital nurses experience a high level of burnout. Exploring biochemical markers of burnout could help to understand physiological changes and may provide useful evidence for preventing burnout symptoms. The current study included 94 female nurses from one Chinese third-level hospital. The Maslach Burnout Inventory-General Survey (MBI-GS) was used to investigate burnout symptoms: emotional exhaustion, cynicism, reduced professional efficacy, as well as the burnout average. The HPT axis was tested by checking blood levels of thyroid-stimulating hormone (TSH), thyroxin (T4) and triiodothyronine (T3). Nonparametric tests showed that no significant difference in biochemical markers was found between the burnout and non-burnout groups. Spearman correlation analysis found that biochemical markers had no significant association with burnout symptoms, except weakly negative associations between reduced professional efficacy and blood pressure and heart rate. These findings show a rather poor correlation of the HPT axis on burnout symptoms. Expanding the biochemical index of the HPT axis, comparing well-defined samples and using longitudinal studies are recommended for further studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Raman Spectra of High-κ Dielectric Layers Investigated with Micro-Raman Spectroscopy Comparison with Silicon Dioxide

    Directory of Open Access Journals (Sweden)

    P. Borowicz

    2013-01-01

    Full Text Available Three samples with dielectric layers from high-κ dielectrics, hafnium oxide, gadolinium-silicon oxide, and lanthanum-lutetium oxide on silicon substrate were studied by Raman spectroscopy. The results obtained for high-κ dielectrics were compared with spectra recorded for silicon dioxide. Raman spectra suggest the similarity of gadolinium-silicon oxide and lanthanum-lutetium oxide to the bulk nondensified silicon dioxide. The temperature treatment of hafnium oxide shows the evolution of the structure of this material. Raman spectra recorded for as-deposited hafnium oxide are similar to the results obtained for silicon dioxide layer. After thermal treatment especially at higher temperatures (600°C and above, the structure of hafnium oxide becomes similar to the bulk non-densified silicon dioxide.

  13. BURNOUT SYNDROME IN PATIENTS WITH WORKPLACE HYPERTENSION

    Directory of Open Access Journals (Sweden)

    Yu. P. Zinchenko

    2016-01-01

    Full Text Available Aim. To study the presence, severity and qualitative characteristics of «burnout syndrome» in patients with «workplace hypertension» (WPH, in comparison with patients with essential hypertension and healthy people.Material and methods. Untreated patients with hypertension stage II, degree 1-2 (n=170; age 32-52 years; mean age 46.7Ѓ}4.1 years were examined. Group 1 included 85 patients with WPH (mean age 44.7Ѓ}4.3 years and Group 2 included 85 patients without WPH (mean age 47.4Ѓ}4.5 years. The duration of hypertension on average was 7.2Ѓ}2.6 years and was comparable in both groups. The control group included 82 healthy subjects (mean age 44.9Ѓ}3.1 years. The Russian version of the Maslach Burnout Inventory (MBI was used to diagnose «burnout syndrome».Results. Signs of «burnout syndrome» were found in the hypertensive patients of both groups. The high and medium levels of the «burnout syndrome» severity according to all three analyzed factors (emotional exhaustion, dehumanization/depersonification, and personal achievements were found in 59% of WPH patients, in 36% of hypertensive patients without WPH, and in 9% of healthy individuals. Most of WPH patients had high emotional exhaustion compared with other groups (27.5Ѓ}3.67 points vs 24.6Ѓ}4.3 and 20.1Ѓ}5.7 points in group 2, and group of healthy, respectively; p<0.05. Hypertensive men rated themselves as less successful professionally in comparison with women. Hypertensive women were more prone to emotional exhaustion and dehumanization/depersonification in comparison with men. Conclusion. Signs of «burnout syndrome» were found significantly more often in hypertensive patients in both groups than in healthy people. Medium and high intensity of all forms of «burnout syndrome» occurred in patients with WPH in comparison with healthy people and hypertensive patients without WPH.

  14. High Performance Optical Waveguides based on Boron and Phosphorous doped Silicon Oxynitride

    NARCIS (Netherlands)

    Sun, F.; Driessen, A.; Worhoff, Kerstin; Broquin, Jean-Emmanuel; Greiner, Christoph M.

    2010-01-01

    Silicon oxynitride (SiON) is a highly attractive material for integrated optics, due to its excellent properties such as high transparency, adjustable refractive index and good stability. In general, the growth of SiON layers by plasma enhanced chemical vapor deposition (PECVD) is followed by a high

  15. Development of manufacturing capability for high-concentration, high-efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, R.A.; Verlinden, P.J.; Crane, R.A.; Swanson, R.N. [SunPower Corp., Sunnyvale, CA (United States)

    1996-10-01

    This report presents a summary of the major results from a program to develop a manufacturable, high-efficiency silicon concentrator solar cell and a cost-effective manufacturing facility. The program was jointly funded by the Electric Power Research Institute, Sandia National Laboratories through the Concentrator Initiative, and SunPower Corporation. The key achievements of the program include the demonstration of 26%-efficient silicon concentrator solar cells with design-point (20 W/cm{sup 2}) efficiencies over 25%. High-performance front-surface passivations; that were developed to achieve this result were verified to be absolutely stable against degradation by 475 days of field exposure at twice the design concentration. SunPower demonstrated pilot production of more than 1500 of these cells. This cell technology was also applied to pilot production to supply 7000 17.7-cm{sup 2} one-sun cells (3500 yielded wafers) that demonstrated exceptional quality control. The average efficiency of 21.3% for these cells approaches the peak efficiency ever demonstrated for a single small laboratory cell within 2% (absolute). Extensive cost models were developed through this program and calibrated by the pilot-production project. The production levels achieved indicate that SunPower could produce 7-10 MW of concentrator cells per year in the current facility based upon the cell performance demonstrated during the program.

  16. [The extent of the burnout syndrome among pharmacists: partial study].

    Science.gov (United States)

    Saligerová, Markéta; Kolář, Jozef

    2017-01-01

    The paper deals with the possibilities of investigating the susceptibility to burnout syndrome in pharmacists and pharmaceutical assistants working in pharmacies. By using the Maslach Burnout Inventory, between November 2015 and January 2016, 53 healthcare professionals were contacted in 11 pharmacies (Brno, Vyškov). The results of the research show that with an increasing length of practice the average EE factor (emotional exhaustion) increases. The DP (depersonalization) factor does not increase significantly with the increase in the length of practice. Respondents with the longest experience are at high risk of burnout syndrome presented by the factor PA (personal satisfaction from work). It has also been shown that with an increasing age the factor EE slightly increases, the DP factor is in the low range, and the PA factor is significantly reduced in the "oldest" age category, it is high in the band.Key words: stress burnout syndrome pharmacists research.

  17. Emotional intelligence as a moderator in the stress-burnout relationship: a questionnaire study on nurses.

    Science.gov (United States)

    Görgens-Ekermans, Gina; Brand, Tamari

    2012-08-01

    To investigate inter-relationships between emotional intelligence (EI), work stress and burnout in a group of nurses in the Western Cape Province, South Africa. The moderating effect of EI in the stress-burnout relationship and group differences (nurses working in different wards) in burnout were also investigated. Stress and subsequent burnout commonly threaten the occupational health and well-being of nurses in South Africa and elsewhere. Developing EI in nurses may increase individual stress resistance and combat burnout. A cross-sectional research design with anonymous questionnaires was conducted. Self-report data were used. Survey data were collected from 122 nurses working in different wards at four hospitals from a private hospital group. The Swinburne University Emotional Intelligence Test, Sources of Work Stress Inventory and Maslach Burnout Inventory were used to measure EI, stress and burnout, respectively. Consistent inverse relationships between emotional control and management as dimensions of EI, and stress and burnout emerged. A differential effect of high vs. low EI on the stress-burnout relationship was evident. Workload and the work/family interface emerged as significant predictors of burnout. Respondents working in maternity, paediatric and ER wards reported more feelings of personal accomplishment than those working in general wards. Higher EI is significantly related with lower stress and burnout in a sample of South African nurses. The moderator effect of EI in the stress-burnout relationship suggests that enhanced EI may help diminish burnout development when chronic stress is experienced. EI developmental interventions, if introduced in nursing curricula, may increase emotional coping resources and enhanced social skills, which may benefit the long-term occupational health of nurses. This may be relevant in developing countries, where environmental stressors related to the organisational context (budget constraints) and wider social

  18. Burnout and its association with resilience in nurses: A cross-sectional study.

    Science.gov (United States)

    Guo, Yu-Fang; Luo, Yuan-Hui; Lam, Louisa; Cross, Wendy; Plummer, Virginia; Zhang, Jing-Ping

    2017-07-05

    To investigate the prevalence and extent of burnout on nurses and its association with personal resilience. With the worldwide shortage of nurses, nurse burnout is considered one of the main contributing factors and has been the focus of studies in recent years. Given the well-documented high level of burnout among nurses, resilience is expected to be a significant predictor of nurse burnout. The association between burnout and resilience has not previously been investigated extensively. A cross-sectional survey design was selected. A total of 1,061 nurses from six separate three-level hospitals in Hunan Province, China, returned self-reported questionnaires from March-June 2015. Data were collected using a socio-demographic sheet, Maslach Burnout Inventory-General Survey and the Connor-Davidson Resilience Scale. Nurses experienced severe burnout symptoms and showed a moderate level of resilience. Three metrics of burnout had significantly negative correlations with the total score and following variables of resilience. Linear regression analysis showed resilience, especially strength, demographic characteristics (exercise, alcohol use and marital status) and job characteristics (income per month, ratio of patients to nurses, shift work and professional rank) were the main predictors of the three metrics of burnout. The findings of this study may help nurse managers and hospital administrators to have a better understanding of nurse burnout and resilience. The significantly negative relationship between burnout symptoms and resilience has been demonstrated, and this informs the role of resilience in influencing burnout. Adaptable and effective interventions for improving resilience are needed to relieve nurses' burnout and reduce workplace stress. Moreover, nurse managers and hospital administrators should establish an effective management system to cultivate a healthy workplace and adopt positive attitudes and harmonious relationships. © 2017 John Wiley & Sons

  19. Demographics and Personality Factors Associated with Burnout among Nurses in a Singapore Tertiary Hospital

    Science.gov (United States)

    Dhaliwal, Satvinder S.; Ayre, Tracy Carol; Uthaman, Thendral; Fong, Kuan Yok; Tien, Choo Eng; Zhou, Huaqiong; Della, Phillip

    2016-01-01

    Background. The aim of the study was to evaluate the prevalence and extent of burnout among nurses in Singapore and investigate the influence of demographic factors and personal characteristics on the burnout syndrome. Methods. A cross-sectional survey design was adopted. All registered nurses working in Singapore General Hospital were approached to participate. A questionnaire eliciting data on demographics, burnout (measured using the Maslach Burnout Inventory, MBI), and personality profile (measured using the NEO Five-Factor Inventory, NEO-FFI) was used. Results. 1830 nurses out of 3588 responded (response rate: 51%). Results from 1826 respondents were available for analysis. The MBI identified 39% to have high emotional exhaustion (EE, cut-off score of >27), 40% having high depersonalization (DP, cut-off score of >10), and 59% having low personal accomplishment (PA, cut-off score of burnout. Personality traits also played a significant role in the experience of burnout. PMID:27478835

  20. The Dark Side of Resilience and Burnout: A Moderation-Mediation Model

    Science.gov (United States)

    Treglown, Luke; Palaiou, Kat; Zarola, Anthony; Furnham, Adrian

    2016-01-01

    This study tested whether specific dark-side traits may be beneficial in manifesting and maintaining Resilience, whilst others are vulnerability factors for Burnout. Four hundred and fifty-one (50 female) ambulance personnel completed three questionnaires as a part of a selection and development assessment. The study utilised the Hogan Development survey as a measure of dark side personality, the Copenhagen Burnout Inventory to assess work-related burnout, and the Resilience Scale– 14 to measure resilience levels. Those high on Excitable and Cautious but low on Bold and Reserved were linked to an increased vulnerability to Burnout. Also those high on Bold and Diligent yet low on the Excitable, Cautious, and Imaginative scales were more resilient. Structural Equation Modelling revealed that resilience plays both a mediating and moderating role on personality and burnout. Theoretical implications suggest future research assessing the predictive capacity of psychological variables on burnout should account the indirect effect of resilience. PMID:27336304

  1. The Dark Side of Resilience and Burnout: A Moderation-Mediation Model.

    Directory of Open Access Journals (Sweden)

    Luke Treglown

    Full Text Available This study tested whether specific dark-side traits may be beneficial in manifesting and maintaining Resilience, whilst others are vulnerability factors for Burnout. Four hundred and fifty-one (50 female ambulance personnel completed three questionnaires as a part of a selection and development assessment. The study utilised the Hogan Development survey as a measure of dark side personality, the Copenhagen Burnout Inventory to assess work-related burnout, and the Resilience Scale- 14 to measure resilience levels. Those high on Excitable and Cautious but low on Bold and Reserved were linked to an increased vulnerability to Burnout. Also those high on Bold and Diligent yet low on the Excitable, Cautious, and Imaginative scales were more resilient. Structural Equation Modelling revealed that resilience plays both a mediating and moderating role on personality and burnout. Theoretical implications suggest future research assessing the predictive capacity of psychological variables on burnout should account the indirect effect of resilience.

  2. Demographics and Personality Factors Associated with Burnout among Nurses in a Singapore Tertiary Hospital.

    Science.gov (United States)

    Ang, Shin Yuh; Dhaliwal, Satvinder S; Ayre, Tracy Carol; Uthaman, Thendral; Fong, Kuan Yok; Tien, Choo Eng; Zhou, Huaqiong; Della, Phillip

    2016-01-01

    Background. The aim of the study was to evaluate the prevalence and extent of burnout among nurses in Singapore and investigate the influence of demographic factors and personal characteristics on the burnout syndrome. Methods. A cross-sectional survey design was adopted. All registered nurses working in Singapore General Hospital were approached to participate. A questionnaire eliciting data on demographics, burnout (measured using the Maslach Burnout Inventory, MBI), and personality profile (measured using the NEO Five-Factor Inventory, NEO-FFI) was used. Results. 1830 nurses out of 3588 responded (response rate: 51%). Results from 1826 respondents were available for analysis. The MBI identified 39% to have high emotional exhaustion (EE, cut-off score of >27), 40% having high depersonalization (DP, cut-off score of >10), and 59% having low personal accomplishment (PA, cut-off score of burnout. Personality traits also played a significant role in the experience of burnout.

  3. High Input Voltage Discharge Supply for High Power Hall Thrusters Using Silicon Carbide Devices

    Science.gov (United States)

    Pinero, Luis R.; Scheidegger, Robert J.; Aulsio, Michael V.; Birchenough, Arthur G.

    2014-01-01

    A power processing unit for a 15 kW Hall thruster is under development at NASA Glenn Research Center. The unit produces up to 400 VDC with two parallel 7.5 kW discharge modules that operate from a 300 VDC nominal input voltage. Silicon carbide MOSFETs and diodes were used in this design because they were the best choice to handle the high voltage stress while delivering high efficiency and low specific mass. Efficiencies in excess of 97 percent were demonstrated during integration testing with the NASA-300M 20 kW Hall thruster. Electromagnet, cathode keeper, and heater supplies were also developed and will be integrated with the discharge supply into a vacuum-rated brassboard power processing unit with full flight functionality. This design could be evolved into a flight unit for future missions that requires high power electric propulsion.

  4. In situ transmission infrared spectroscopy of high-kappa oxide atomic layer deposition onto silicon surfaces

    Science.gov (United States)

    Ho, Ming-Tsung

    -H...Hf interactions or by the dielectric screening effect of as-grown high-kappa moiety. A summary of local bonding models with vibrational mode assignments of the adsorbed TMA and TEMAH on silicon surfaces is presented based on the analysis of the substructure of silicate interfacial band at 900--1100 cm-1.

  5. Silicon sheet with molecular beam epitaxy for high efficiency solar cells

    Science.gov (United States)

    Allen, F. G.

    1983-01-01

    The capabilities of the new technique of Molecular Beam Epitaxy (MBE) are applied to the growth of high efficiency silicon solar cells. Because MBE can provide well controlled doping profiles of any desired arbitrary design, including doping profiles of such complexity as built-in surface fields or tandem junction cells, it would appear to be the ideal method for development of high efficiency solar cells. It was proposed that UCLA grow and characterize silicon films and p-n junctions of MBE to determine whether the high crystal quality needed for solar cells could be achieved.

  6. Interfacial Engineering of Silicon Carbide Nanowire/Cellulose Microcrystal Paper toward High Thermal Conductivity.

    Science.gov (United States)

    Yao, Yimin; Zeng, Xiaoliang; Pan, Guiran; Sun, Jiajia; Hu, Jiantao; Huang, Yun; Sun, Rong; Xu, Jian-Bin; Wong, Ching-Ping

    2016-11-16

    Polymer composites with high thermal conductivity have attracted much attention, along with the rapid development of electronic devices toward higher speed and better performance. However, high interfacial thermal resistance between fillers and matrix or between fillers and fillers has been one of the primary bottlenecks for the effective thermal conduction in polymer composites. Herein, we report on engineering interfacial structure of silicon carbide nanowire/cellulose microcrystal paper by generating silver nanostructures. We show that silver nanoparticle-deposited silicon carbide nanowires as fillers can effectively enhance the thermal conductivity of the matrix. The in-plane thermal conductivity of the resultant composite paper reaches as high as 34.0 W/m K, which is one order magnitude higher than that of conventional polymer composites. Fitting the measured thermal conductivity with theoretical models qualitatively demonstrates that silver nanoparticles bring the lower interfacial thermal resistances both at silicon carbide nanowire/cellulose microcrystal and silicon carbide nanowire/silicon carbide nanowire interfaces. This interfacial engineering approach provides a powerful tool for sophisticated fabrication of high-performance thermal-management materials.

  7. High quality silicon-based substrates for microwave and millimeter wave passive circuits

    Science.gov (United States)

    Belaroussi, Y.; Rack, M.; Saadi, A. A.; Scheen, G.; Belaroussi, M. T.; Trabelsi, M.; Raskin, J.-P.

    2017-09-01

    Porous silicon substrate is very promising for next generation wireless communication requiring the avoidance of high-frequency losses originating from the bulk silicon. In this work, new variants of porous silicon (PSi) substrates have been introduced. Through an experimental RF performance, the proposed PSi substrates have been compared with different silicon-based substrates, namely, standard silicon (Std), trap-rich (TR) and high resistivity (HR). All of the mentioned substrates have been fabricated where identical samples of CPW lines have been integrated on. The new PSi substrates have shown successful reduction in the substrate's effective relative permittivity to values as low as 3.7 and great increase in the substrate's effective resistivity to values higher than 7 kΩ cm. As a concept proof, a mm-wave bandpass filter (MBPF) centred at 27 GHz has been integrated on the investigated substrates. Compared with the conventional MBPF implemented on standard silicon-based substrates, the measured S-parameters of the PSi-based MBPF have shown high filtering performance, such as a reduction in insertion loss and an enhancement of the filter selectivity, with the joy of having the same filter performance by varying the temperature. Therefore, the efficiency of the proposed PSi substrates has been well highlighted. From 1994 to 1995, she was assistant of physics at (USTHB), Algiers . From 1998 to 2011, she was a Researcher at characterization laboratory in ionized media and laser division at the Advanced Technologies Development Center. She has integrated the Analog Radio Frequency Integrated Circuits team as Researcher since 2011 until now in Microelectronic and Nanotechnology Division at Advanced Technologies Development Center (CDTA), Algiers. She has been working towards her Ph.D. degree jointly at CDTA and Ecole Nationale Polytechnique, Algiers, since 2012. Her research interest includes fabrication and characterization of microwave passive devices on porous

  8. High Temperature Joining and Characterization of Joint Properties in Silicon Carbide-Based Composite Materials

    Science.gov (United States)

    Halbig, Michael C.; Singh, Mrityunjay

    2015-01-01

    Advanced silicon carbide-based ceramics and composites are being developed for a wide variety of high temperature extreme environment applications. Robust high temperature joining and integration technologies are enabling for the fabrication and manufacturing of large and complex shaped components. The development of a new joining approach called SET (Single-step Elevated Temperature) joining will be described along with the overview of previously developed joining approaches including high temperature brazing, ARCJoinT (Affordable, Robust Ceramic Joining Technology), diffusion bonding, and REABOND (Refractory Eutectic Assisted Bonding). Unlike other approaches, SET joining does not have any lower temperature phases and will therefore have a use temperature above 1315C. Optimization of the composition for full conversion to silicon carbide will be discussed. The goal is to find a composition with no remaining carbon or free silicon. Green tape interlayers were developed for joining. Microstructural analysis and preliminary mechanical tests of the joints will be presented.

  9. Graphene oxide-immobilized NH₂-terminated silicon nanoparticles by cross-linked interactions for highly stable silicon negative electrodes.

    Science.gov (United States)

    Sun, Cheng; Deng, Yuanfu; Wan, Lina; Qin, Xusong; Chen, Guohua

    2014-07-23

    There is a great interest in the utilization of silicon-based anodes for lithium-ion batteries. However, its poor cycling stability, which is caused by a dramatic volume change during lithium-ion intercalation, and intrinsic low electric conductivity hamper its industrial applications. A facile strategy is reported here to fabricate graphene oxide-immobilized NH2-terminated silicon nanoparticles (NPs) negative electrode (Si@NH2/GO) directed by hydrogen bonding and cross-linked interactions to enhance the capacity retention of the anode. The NH2-modified Si NPs first form strong hydrogen bonds and covalent bonds with GO. The Si@NH2/GO composite further forms hydrogen bonds and covalent bonds with sodium alginate, which acts as a binder, to yield a stable composite negative electrode. These two chemical cross-linked/hydrogen bonding interactions-one between NH2-modified Si NPs and GO, and another between the GO and sodium alginate-along with highly mechanically flexible graphene oxide, produced a robust network in the negative electrode system to stabilize the electrode during discharge and charge cycles. The as-prepared Si@NH2/GO electrode exhibits an outstanding capacity retention capability and good rate performance, delivering a reversible capacity of 1000 mAh g(-1) after 400 cycles at a current of 420 mA g(-1) with almost 100% capacity retention. The results indicated the importance of system-level strategy for fabricating stable electrodes with improved electrochemical performance.

  10. GENDER AND STUDENT BURNOUT SYNDROME

    National Research Council Canada - National Science Library

    Cecilia López-Pozos

    2014-01-01

    This article is about the influence of postmodernism on development of the burnout syndrome academic, manifested in various symptomatologies involved in the academic performance of the female gender...

  11. Medical Student Stress, Burnout and Depression in Trinidad and Tobago.

    Science.gov (United States)

    Youssef, Farid F

    2016-02-01

    Health-care workers in developed nations are well known to experience high levels of burnout and psychiatric morbidity, but little information is available from the Caribbean and other less well-developed regions. This study sought to explore the prevalence of stress, burnout, and depressive symptoms and associated risk factors among medical students in Trinidad and Tobago, the southernmost Caribbean island. A cross-sectional survey design was used to sample students. Data was collected utilizing standardized questionnaires that assess stress, burnout, and depressive symptoms. Demographic data and information pertaining to potential risk factors was also gathered. Overall, 450 questionnaires were distributed and analysis was performed upon 381 completed surveys (response rate 85%). Students demonstrated high levels of stress and a significant prevalence of burnout (52%) and depressive symptoms (40%). Final year students demonstrated higher levels of burnout and depressive symptoms. Students who (i) felt they lacked emotional support, (ii) had little opportunity for relaxation and exercise, and (iii) did not feel they had control of their daily schedule all demonstrated higher levels of burnout and depressive symptoms. However, students who practiced from a faith base and considered their religion important demonstrated lower levels of both. Medical students in Trinidad and Tobago are experiencing high levels of stress with a large proportion suffering from burnout and depressive symptoms. These data suggest that immediate interventions are necessary to help students cope with the challenges faced during medical school. Additionally, more research is needed to explore the potential causal links between burnout and depression during medical school and the effectiveness of tailored interventions especially within the context of developing nations.

  12. The relationship between burnout and mental health among nurses

    Directory of Open Access Journals (Sweden)

    Abdi masooleh F

    2007-09-01

    Full Text Available Background: Burnout is one of the most important factors in reduced productivity in organizations and involves physical and mental signs, especially in the human service professions. The role of nurses in the healthcare system is vital and motivation to ensure health security is extremely important. We carried out this research to examine the relationship between burnout and mental health in the nursing staff of educational hospitals of Tehran University of Medical Sciences.Methods: A descriptive cross-sectional survey was conducted among 200 nurses selected via probable multistage sampling. We used three instruments in this study: 1 demographic questionnaire 2 General Health Questionnaire-28 (GHQ-28 and 3 Maslach Burnout Inventory (MBI.Results: On the whole, using the MBI subscale, we found low levels of emotional exhaustion and depersonalization and high levels of reduced sense of personal accomplishment, both in frequency and intensity. The prevalence of symptomatic samples in the GHQ-28 was 43%, and two variables, burnout and poor mental health, were related (p<0.001. Burnout was to be related to gender, age and years of work. The correlation between poor mental health and years of work as well as hours of work in a week were significant. Conclusions: Our results suggest that there is a strong correlation between poor mental health and burnout. Furthermore, the prevalence of symptomatic samples detected in our study using the GHQ-28 was much higher than that reported in studies of the general population. The high prevalence of symptomatic samples and high prevalence of burnout in the dimension of self accomplishment, especially in younger nurses, combined with the strong correlation between poor mental health and burnout all show that care should be taken to improve the stressful conditions that nurses face.

  13. [Syndrome of emotional burnout among women-physicians elderly].

    Science.gov (United States)

    Myakotnykh, V S; Borovkova, T A

    2017-01-01

    The article presents the results of a comparative study of clinical symptoms of syndrome of emotional burnout among 84 working in the specialty physician of older women and 48 officially ceasing operations in this specialty. The findings suggest that burnout can take place among representatives of older age and more it is continued, provided professional activities. The cessation of the work activities leads to stress, often with the subsequent development post-traumatic stress disorder and stress-induced diseases. However in this case the clinical symptoms of the syndrome of emotional burnout, does not disappear, but only happens their clinical transformation attach various psychosomatic disorders. Thus, the elderly, suffering the syndrome of emotional burnout, are at high risk group with regard to the formation and development of diseases, associated with stress and require close monitoring in the framework of the compulsory program of medical examination.

  14. Scalable synthesis of silicon-nanolayer-embedded graphite for high-energy lithium-ion batteries

    Science.gov (United States)

    Ko, Minseong; Chae, Sujong; Ma, Jiyoung; Kim, Namhyung; Lee, Hyun-Wook; Cui, Yi; Cho, Jaephil

    2016-09-01

    Existing anode technologies are approaching their limits, and silicon is recognized as a potential alternative due to its high specific capacity and abundance. However, to date the commercial use of silicon has not satisfied electrode calendering with limited binder content comparable to commercial graphite anodes for high energy density. Here we demonstrate the feasibility of a next-generation hybrid anode using silicon-nanolayer-embedded graphite/carbon. This architecture allows compatibility between silicon and natural graphite and addresses the issues of severe side reactions caused by structural failure of crumbled graphite dust and uncombined residue of silicon particles by conventional mechanical milling. This structure shows a high first-cycle Coulombic efficiency (92%) and a rapid increase of the Coulombic efficiency to 99.5% after only 6 cycles with a capacity retention of 96% after 100 cycles, with an industrial electrode density of >1.6 g cm-3, areal capacity loading of >3.3 mAh cm-2, and <4 wt% binding materials in a slurry. As a result, a full cell using LiCoO2 has demonstrated a higher energy density (1,043 Wh l-1) than with standard commercial graphite electrodes.

  15. Emotional competence relating to perceived stress and burnout in Spanish teachers: a mediator model

    Science.gov (United States)

    Extremera, Natalio

    2016-01-01

    This study examined direct associations between emotional competence, perceived stress and burnout in 489 Spanish teachers. In addition, a model in which perceived stress mediated pathways linking emotional competence to teacher burnout symptoms was also examined. Results showed that emotional competence and stress were significantly correlated with teacher burnout symptoms in the expected direction. Moreover, mediational analysis indicated that perceived stress partly mediated the relationship between emotional competence and the three dimensions of burnout even when controlling for salient background characteristics. These findings suggest an underlying process by which high emotional competence may increase the capacity to cope with symptoms of burnout, by reducing the experience of stress. Implications of these findings for future research and for working with teachers to prevent burnout are discussed. PMID:27280077

  16. [Communication skills: a preventive factor in Burnout syndrome in health professionals].

    Science.gov (United States)

    Leal-Costa, C; Díaz-Agea, J L; Tirado-González, S; Rodríguez-Marín, J; van-der Hofstadt, C J

    2015-01-01

    Health professionals are a group that suffers high levels of job stress and burnout. The aim of this study is to demonstrate empirically that the healthcare count on communication skills helps prevent Burnout Syndrome. An observational, analytical, cross-sectional study was proposed, involving a sample of 927 health professionals (197 doctors, 450 nurses and 280 auxiliary nurses). Participants completed questionnaires measuring communication skills in health care (EHC-PS) and the Maslach Burnout Inventory Human Services Survey (MBI-HSS). A negative and statistically significant correlation between the different dimensions of communication skills and emotional exhaustion and depersonalization dimensions of burnout was obtained. On the other hand, a positive and statistically significant correlation between the dimensions of communication skills and the personal accomplishment dimension of burnout was observed. It was shown that the communication skills of health professionals provide protection from and cushion Burnout Syndrome.

  17. Emotional competence relating to perceived stress and burnout in Spanish teachers: a mediator model.

    Science.gov (United States)

    Rey, Lourdes; Extremera, Natalio; Pena, Mario

    2016-01-01

    This study examined direct associations between emotional competence, perceived stress and burnout in 489 Spanish teachers. In addition, a model in which perceived stress mediated pathways linking emotional competence to teacher burnout symptoms was also examined. Results showed that emotional competence and stress were significantly correlated with teacher burnout symptoms in the expected direction. Moreover, mediational analysis indicated that perceived stress partly mediated the relationship between emotional competence and the three dimensions of burnout even when controlling for salient background characteristics. These findings suggest an underlying process by which high emotional competence may increase the capacity to cope with symptoms of burnout, by reducing the experience of stress. Implications of these findings for future research and for working with teachers to prevent burnout are discussed.

  18. High surface area silicon carbide-coated carbon aerogel

    Science.gov (United States)

    Worsley, Marcus A; Kuntz, Joshua D; Baumann, Theodore F; Satcher, Jr, Joe H

    2014-01-14

    A metal oxide-carbon composite includes a carbon aerogel with an oxide overcoat. The metal oxide-carbon composite is made by providing a carbon aerogel, immersing the carbon aerogel in a metal oxide sol under a vacuum, raising the carbon aerogel with the metal oxide sol to atmospheric pressure, curing the carbon aerogel with the metal oxide sol at room temperature, and drying the carbon aerogel with the metal oxide sol to produce the metal oxide-carbon composite. The step of providing a carbon aerogel can provide an activated carbon aerogel or provide a carbon aerogel with carbon nanotubes that make the carbon aerogel mechanically robust. Carbon aerogels can be coated with sol-gel silica and the silica can be converted to silicone carbide, improved the thermal stability of the carbon aerogel.

  19. Status Analysis on the Learning Burnout of Suburban Junior High School Students%城郊乡镇初中生学习倦怠的现状分析

    Institute of Scientific and Technical Information of China (English)

    黄桂新

    2013-01-01

    Learning Burnout is used to describe the students in the learning process can not effectively cope with learning problems such as bore⁃dom, fatigue, depression and frustration, and then produces a series of inappropriate behavior to avoid learning. Adapted on the basis of existing learning burnout research questionnaire, this paper conducts research in order to understand their learning burnout in the suburban rural junior high schools in Nanning, Guangxi, and to propose a solution.%  学习倦怠用于描述学生在学习过程中不能有效的应付学习的问题而产生的诸如厌倦、疲乏、沮丧和挫折等极端的心理反应,继而产生一系列不适当的逃避学习的行为。在已有学习倦怠研究的基础上改编问卷,对广西南宁市城郊乡镇初中生进行调研以期了解目前他们的学习倦怠现状,并提出对策。

  20. Risk factors and prevalence of burnout syndrome in the nursing profession.

    Science.gov (United States)

    Cañadas-De la Fuente, Guillermo A; Vargas, Cristina; San Luis, Concepción; García, Inmaculada; Cañadas, Gustavo R; De la Fuente, Emilia I

    2015-01-01

    The burnout syndrome is beginning to be regarded as an occupational illness of high prevalence among nursing in Spain. Individuals suffering from the syndrome manifest important health problems. More information about prevalence and risk factors for burnout is needed to prevent the syndrome and to determine the most appropriate clinical interventions when the disorder appears. Burnout levels were evaluated in a group of nurses. The objectives of this study were to estimate the prevalence of burnout, to identify the variables related to burnout and to propose a risk profile for this syndrome among the nursing personnel. The study was carried out in public health centers in Andalusia (Spain). The sample consisted of 676 nursing professionals from public health centers. Dependent variables were the three Burnout dimensions: emotional exhaustion, depersonalization and personal accomplishment. Independent variables were socio-demographic, organizational, personality-related variables. The nurses manifested average to high burnout levels. There were statistically significant differences in burnout levels associated with the following variables: age, gender, marital status, having children, level of healthcare, type of work shift, healthcare service areas and conducting administrative tasks. Burnout was also associated with personality-related variables. The prevalence of burnout among nursing professionals is high. Gender, age, marital status, level of healthcare, work shift and healthcare service areas predicted at least one of the dimensions of the syndrome. Neuroticism, agreeability, extraversion and conscientiousness are personality traits that predict at least two of the dimensions of burnout syndrome in nurses. Therefore, personality factors should be considered in any theory of risk profiles for developing burnout syndrome in the nursing profession. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Silicon carbide-free graphene growth on silicon for lithium-ion battery with high volumetric energy density

    Science.gov (United States)

    Son, In Hyuk; Hwan Park, Jong; Kwon, Soonchul; Park, Seongyong; Rümmeli, Mark H.; Bachmatiuk, Alicja; Song, Hyun Jae; Ku, Junhwan; Choi, Jang Wook; Choi, Jae-man; Doo, Seok-Gwang; Chang, Hyuk

    2015-01-01

    Silicon is receiving discernable attention as an active material for next generation lithium-ion battery anodes because of its unparalleled gravimetric capacity. However, the large volume change of silicon over charge–discharge cycles weakens its competitiveness in the volumetric energy density and cycle life. Here we report direct graphene growth over silicon nanoparticles without silicon carbide formation. The graphene layers anchored onto the silicon surface accommodate the volume expansion of silicon via a sliding process between adjacent graphene layers. When paired with a commercial lithium cobalt oxide cathode, the silicon carbide-free graphene coating allows the full cell to reach volumetric energy densities of 972 and 700 Wh l−1 at first and 200th cycle, respectively, 1.8 and 1.5 times higher than those of current commercial lithium-ion batteries. This observation suggests that two-dimensional layered structure of graphene and its silicon carbide-free integration with silicon can serve as a prototype in advancing silicon anodes to commercially viable technology. PMID:26109057

  2. Silicon carbide-free graphene growth on silicon for lithium-ion battery with high volumetric energy density.

    Science.gov (United States)

    Son, In Hyuk; Hwan Park, Jong; Kwon, Soonchul; Park, Seongyong; Rümmeli, Mark H; Bachmatiuk, Alicja; Song, Hyun Jae; Ku, Junhwan; Choi, Jang Wook; Choi, Jae-Man; Doo, Seok-Gwang; Chang, Hyuk

    2015-06-25

    Silicon is receiving discernable attention as an active material for next generation lithium-ion battery anodes because of its unparalleled gravimetric capacity. However, the large volume change of silicon over charge-discharge cycles weakens its competitiveness in the volumetric energy density and cycle life. Here we report direct graphene growth over silicon nanoparticles without silicon carbide formation. The graphene layers anchored onto the silicon surface accommodate the volume expansion of silicon via a sliding process between adjacent graphene layers. When paired with a commercial lithium cobalt oxide cathode, the silicon carbide-free graphene coating allows the full cell to reach volumetric energy densities of 972 and 700 Wh l(-1) at first and 200th cycle, respectively, 1.8 and 1.5 times higher than those of current commercial lithium-ion batteries. This observation suggests that two-dimensional layered structure of graphene and its silicon carbide-free integration with silicon can serve as a prototype in advancing silicon anodes to commercially viable technology.

  3. Ion heating, burnout of the high-frequency field, and ion sound generation under the development of a modulation instability of an intense Langmuir wave in a plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kirichok, A. V., E-mail: sandyrcs@gmail.com; Kuklin, V. M.; Pryimak, A. V. [Institute for High Technologies, V.N. Karazin Kharkiv National University, 4 Svobody Sq., Kharkiv 61022 (Ukraine); Zagorodny, A. G. [Bogolyubov Institute for Theoretical Physics, 14-b, Metrolohichna str., Kiev 03680 (Ukraine)

    2015-09-15

    The development of one-dimensional parametric instabilities of intense long plasma waves is considered in terms of the so-called hybrid models, with electrons being treated as a fluid and ions being regarded as particles. The analysis is performed for both cases when the average plasma field energy is lower (Zakharov's hybrid model—ZHM) or greater (Silin's hybrid model—SHM) than the plasma thermal energy. The efficiency of energy transfer to ions and to ion perturbations under the development of the instability is considered for various values of electron-to-ion mass ratios. The energy of low-frequency oscillations (ion-sound waves) is found to be much lower than the final ion kinetic energy. We also discuss the influence of the changes in the damping rate of the high-frequency (HF) field on the instability development. The decrease of the absorption of the HF field inhibits the HF field burnout within plasma density cavities and gives rise to the broadening of the HF spectrum. At the same time, the ion velocity distribution tends to the normal distribution in both ZHM and SHM.

  4. Ion heating, burnout of the high-frequency field, and ion sound generation under the development of a modulation instability of an intense Langmuir wave in a plasma

    Science.gov (United States)

    Kirichok, A. V.; Kuklin, V. M.; Pryimak, A. V.; Zagorodny, A. G.

    2015-09-01

    The development of one-dimensional parametric instabilities of intense long plasma waves is considered in terms of the so-called hybrid models, with electrons being treated as a fluid and ions being regarded as particles. The analysis is performed for both cases when the average plasma field energy is lower (Zakharov's hybrid model—ZHM) or greater (Silin's hybrid model—SHM) than the plasma thermal energy. The efficiency of energy transfer to ions and to ion perturbations under the development of the instability is considered for various values of electron-to-ion mass ratios. The energy of low-frequency oscillations (ion-sound waves) is found to be much lower than the final ion kinetic energy. We also discuss the influence of the changes in the damping rate of the high-frequency (HF) field on the instability development. The decrease of the absorption of the HF field inhibits the HF field burnout within plasma density cavities and gives rise to the broadening of the HF spectrum. At the same time, the ion velocity distribution tends to the normal distribution in both ZHM and SHM.

  5. Application of artificial neural networks to a study of nursing burnout.

    Science.gov (United States)

    Ladstätter, F; Garrosa, E; Badea, C; Moreno, B

    2010-09-01

    Nursing is generally considered to be a profession with high levels of emotional and physical stress that tend to increase. These high stress levels lead to a high risk of burnout. The objective was to assess whether artificial neural network (ANN) paradigms offer greater predictive accuracy than statistical methodologies, which are commonly used in the field of burnout. A radial basis function (RBF) network and hierarchical stepwise regression was used to assess burnout. The comparison of the two methodologies was carried out by analysing a sample of 462 nurses and student nurses. The subjects were from three hospitals in Madrid (Spain), who completed the 'Nursing Burnout Scale' survey. A RBF network was better suited for the analysis of burnout than hierarchical stepwise regression. The outcomes indicate furthermore that the relationship with the burnout process of the predictive variables age, job status, workload, experience with pain and death, conflictive interaction, role ambiguity and hardy personality is not entirely linear. The usage of ANNs in the field of burnout has been justified due to their superior ability to capture non-linear relationships, which is relevant for theory development. STATEMENT OF RELEVANCE: Due to the superior ability to capture non-linear relationships, ANNs are better suited to explain and predict burnout and its subdimensions than common statistical methods. From this perspective, more specific programmes to prevent burnout and its consequences in the workplace can be designed.

  6. Contingent self-esteem, stressors and burnout in working women and men.

    Science.gov (United States)

    Blom, Victoria

    2012-01-01

    A high work involvement is considered central in the burnout process. Yet, research investigating how high work involvement and psychosocial stressors relate to burnout is scarce. High involvement in terms of performance-based self-esteem (PBSE) refers to individuals' strivings to validate self-worth by achievements, a disposition linked to poor health. The aim of the present study was to examine longitudinally PBSE in relation to burnout while also taking into account work- and private life stressors. The sample consisted of 2121 working women and men. Main- and mediation effects were investigated using hierarchical regression analysis. The results showed performance-based self-esteem mediated partially between the stressors and burnout. Performance-based self-esteem was the strongest predictor of burnout over time, followed by private life stressors. Women experienced more work stress than did men. Men had stronger associations between work stressors and burnout, while women had stronger associations between performance-based self-esteem and burnout. Individual characteristics along with both private life and work stressors are important predictors of burnout. Factors associated with burnout differ somewhat between women and men.

  7. High-Q silicon-on-insulator optical rib waveguide racetrack resonators

    Science.gov (United States)

    Kiyat, Isa; Aydinli, Atilla; Dagli, Nadir

    2005-03-01

    In this work, detailed design and realization of high quality factor (Q) racetrack resonators based on silicon-on-insulator rib waveguides are presented. Aiming to achieve critical coupling, suitable waveguide geometry is determined after extensive numerical studies of bending loss. The final design is obtained after coupling factor calculations and estimation of propagation loss. Resonators with quality factors (Q) as high as 119000 has been achieved, the highest Q value for resonators based on silicon-on-insulator rib waveguides to date with extinction ratios as large as 12 dB.

  8. Shear dependent nonlinear vibration in a high quality factor single crystal silicon micromechanical resonator

    Science.gov (United States)

    Zhu, H.; Shan, G. C.; Shek, C. H.; Lee, J. E.-Y.

    2012-07-01

    The frequency response of a single crystal silicon resonator under nonlinear vibration is investigated and related to the shear property of the material. The shear stress-strain relation of bulk silicon is studied using a first-principles approach. By incorporating the calculated shear property into a device-level model, our simulation closely predicts the frequency response of the device obtained by experiments and further captures the nonlinear features. These results indicate that the observed nonlinearity stems from the material's mechanical property. Given the high quality factor (Q) of the device reported here (˜2 × 106), this makes it highly susceptible to such mechanical nonlinear effects.

  9. Fundamental understanding and development of low-cost, high-efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    ROHATGI,A.; NARASIMHA,S.; MOSCHER,J.; EBONG,A.; KAMRA,S.; KRYGOWSKI,T.; DOSHI,P.; RISTOW,A.; YELUNDUR,V.; RUBY,DOUGLAS S.

    2000-05-01

    The overall objectives of this program are (1) to develop rapid and low-cost processes for manufacturing that can improve yield, throughput, and performance of silicon photovoltaic devices, (2) to design and fabricate high-efficiency solar cells on promising low-cost materials, and (3) to improve the fundamental understanding of advanced photovoltaic devices. Several rapid and potentially low-cost technologies are described in this report that were developed and applied toward the fabrication of high-efficiency silicon solar cells.

  10. Radiation-hard silicon photonics for high energy physics and beyond

    CERN Document Server

    CERN. Geneva

    2016-01-01

    Silicon photonics (SiPh) is currently being investigated as a promising technology for future radiation hard optical links. The possibility of integrating SiPh devices with electronics and/or silicon particle sensors as well as an expected very high resistance against radiation damage make this technology particularly interesting for potential use close to the interaction points in future in high energy physics experiments and other radiation-sensitive applications. The presentation will summarize the outcomes of the research on radiation hard SiPh conducted within the ICE-DIP projected.

  11. High-Q silicon-on-insulator optical rib waveguide racetrack resonators.

    Science.gov (United States)

    Kiyat, Isa; Aydinli, Atilla; Dagli, Nadir

    2005-03-21

    In this work, detailed design and realization of high quality factor (Q) racetrack resonators based on silicon-on-insulator rib waveguides are presented. Aiming to achieve critical coupling, suitable waveguide geometry is determined after extensive numerical studies of bending loss. The final design is obtained after coupling factor calculations and estimation of propagation loss. Resonators with quality factors (Q) as high as 119000 has been achieved, the highest Q value for resonators based on silicon-on-insulator rib waveguides to date with extinction ratios as large as 12 dB.

  12. A new Design for an High Gain Vacuum Photomultiplier: The Silicon PMT Used as Amplification Stage

    Energy Technology Data Exchange (ETDEWEB)

    Barbarino, Giancarlo [Universita di Napoli ' Federico II' , Dipartimento di Scienze fisiche, via Cintia 80126 Napoli (Italy); Asmundis, Riccardo de; De Rosa, Gianfranca [Istituto Nazionale di fisica Nucleare, sezione di Napoli, Complesso di Monte S. Angelo Ed. 6, via Cintia 80126 Napoli (Italy); Fiorillo, Giuliana; Russo, Stefano [Universita di Napoli ' Federico II' , Dipartimento di Scienze fisiche, via Cintia 80126 Napoli (Italy)

    2009-12-15

    Photons detection will continue to be a channel of great interest in the High Energy Physics and Astroparticle Physics fields for medium and big scale experiments in the next future. Thus, new solutions for photon detectors, that overcome the current limits of classical photomultipliers, are welcomed. We propose an innovative design for a hybrid, modern, high gain Vacuum Silicon Photomultiplier Tube (VSiPMT) which is boosted by the recent Geiger-mode avalanche silicon photodiode (G-APD) for which a massive production is today available.

  13. Validation of the Maslach Burnout Inventory-Human Services Survey for Estimating Burnout in Dental Students.

    Science.gov (United States)

    Montiel-Company, José María; Subirats-Roig, Cristian; Flores-Martí, Pau; Bellot-Arcís, Carlos; Almerich-Silla, José Manuel

    2016-11-01

    The aim of this study was to examine the validity and reliability of the Maslach Burnout Inventory-Human Services Survey (MBI-HSS) as a tool for assessing the prevalence and level of burnout in dental students in Spanish universities. The survey was adapted from English to Spanish. A sample of 533 dental students from 15 Spanish universities and a control group of 188 medical students self-administered the survey online, using the Google Drive service. The test-retest reliability or reproducibility showed an Intraclass Correlation Coefficient of 0.95. The internal consistency of the survey was 0.922. Testing the construct validity showed two components with an eigenvalue greater than 1.5, which explained 51.2% of the total variance. Factor I (36.6% of the variance) comprised the items that estimated emotional exhaustion and depersonalization. Factor II (14.6% of the variance) contained the items that estimated personal accomplishment. The cut-off point for the existence of burnout achieved a sensitivity of 92.2%, a specificity of 92.1%, and an area under the curve of 0.96. Comparison of the total dental students sample and the control group of medical students showed significantly higher burnout levels for the dental students (50.3% vs. 40.4%). In this study, the MBI-HSS was found to be viable, valid, and reliable for measuring burnout in dental students. Since the study also found that the dental students suffered from high levels of this syndrome, these results suggest the need for preventive burnout control programs.

  14. Professional burnout and its correlates in Lithuanian neurosurgeons.

    Science.gov (United States)

    Pranckeviciene, Aiste; Tamasauskas, Arimantas; Deltuva, Vytenis Pranas; Bunevicius, Adomas

    2016-08-01

    This study aimed to evaluate prevalence and severity of professional burnout in a sample of Lithuanian neurosurgeons and to analyze its personal, interpersonal, and organizational correlates. Thirty-one out of 79 (response rate 39 %) Lithuanian neurosurgeons participated in the study. Professional burnout was evaluated using the Maslach Burnout Inventory - General Survey. Participants also answered questions about professional stressors, sources of professional dissatisfaction, life-style factors, sickness absenteeism/presenteeism, and professional practice. The majority of neurosurgeons were between 41 and 60 years of age (48 %), were married (97 %), had children (84 %). Most neurosurgeons had 20 or more years of professional experience (54.9 %), worked from 41 to 60 h per week (58 %), and performed up to 150 surgeries per year (77.4 %). Eight (26 %) neurosurgeons reported a high level of emotional exhaustion, five (16 %) reported high level of cynicism, and eight (26 %) reported low professional efficacy. Correlation analyses revealed that higher number of surgeries per year, more hours devoted to clinical work, opportunities for professional development, intellectual challenges at work, appreciation by the patients and prestige of the profession were related to lower level of burnout. Greater general workload, unpredictability of the work schedule, lack of necessary technical equipment, dissatisfaction with colleagues, and uncertainty about the future were related to a higher level of burnout. Burnout was reported by one-quarter of neurosurgeons who chose to participate in the study. Personal, interpersonal, and organizational factors arising while fulfilling professional duties were important correlates of neurosurgeons' burnout. Due to the moderate response rate, our results should be interpreted with caution. Larger studies evaluating burnout among European neurosurgeons are needed.

  15. Síndrome de Burnout em graduandos de Odontologia Burnout syndrome among dental students

    Directory of Open Access Journals (Sweden)

    Juliana Alvares Duarte Bonini Campos

    2012-03-01

    Full Text Available A Síndrome de Burnout caracteriza-se por esgotamento profissional e tem sido relatada em estudantes universitários. O objetivo desse estudo foi estimar a prevalência da Síndrome de Burnout em estudantes de Odontologia de uma universidade pública e sua relação com características sociodemográficas. Todos os estudantes (n = 300 foram convidados a participar. Utilizou-se o Inventário de Burnout de Maslach - versão estudantes (MBI-SS. Realizou-se análise das propriedades psicométricas do MBI-SS. Para comparação entre os escores médios das dimensões do Burnout realizou-se Análise de Variância Multivariada (MANOVA seguida de Análise de Variância (ANOVA e testes post-hoc de Tukey. Dos 235 participantes, 72,8% eram mulheres e a média de idade era de 21,0 ± 1,8 anos. O MBI-SS mostrou-se confiável e válido. Dos estudantes, 17,0% apresentaram a Síndrome de Burnout. Verificou-se relação significativa entre a Síndrome de Burnout e o desempenho do estudante no curso (F = 4,433, p The burnout syndrome is characterized by professional exhaustion and has been reported in college students. The aim of this study was to estimate the prevalence of Burnout Syndrome among dentistry students from a public university, and its relationship to socio-demographic characteristics. All students (n = 300 were invited to participate. We used the Maslach Burnout Inventory - Student Version (MBI-SS. We carried out an analysis of the MBI-SS' psychometric properties. Multivariate Analysis of Variance (MANOVA was performed, followed by Analysis of Variance (ANOVA and Tukey's post-hoc tests to compare the mean scores of burnout dimensions. Of the 235 participants, 72.8% were women and the mean age was 21.0 ± 1.8 years. The MBI-SS was reliable and valid. Of the students, 17.0% had Burnout Syndrome. There was a significant relation between Burnout Syndrome and a student's performance during the course (F = 4.433, p < 0.001, medication intake because of

  16. Hierarchical columnar silicon anode structures for high energy density lithium sulfur batteries

    Science.gov (United States)

    Piwko, Markus; Kuntze, Thomas; Winkler, Sebastian; Straach, Steffen; Härtel, Paul; Althues, Holger; Kaskel, Stefan

    2017-05-01

    Silicon is a promising anode material for next generation lithium secondary batteries. To significantly increase the energy density of state of the art batteries with silicon, new concepts have to be developed and electrode structuring will become a key technology. Structuring is essential to reduce the macroscopic and microscopic electrode deformation, caused by the volume change during cycling. We report pulsed laser structuring for the generation of hierarchical columnar silicon films with outstanding high areal capacities up to 7.5 mAh cm-2 and good capacity retention. Unstructured columnar electrodes form a micron-sized block structure during the first cycle to compensate the volume expansion leading to macroscopic electrode deformation. At increased silicon loading, without additional structuring, pronounced distortion and the formation of cracks through the current collector causes cell failure. Pulsed laser ablation instead is demonstrated to avoid macroscopic electrode deformation by initial formation of the block structure. A full cell with lithiated silicon versus a carbon-sulfur cathode is assembled with only 15% overbalanced anode and low electrolyte amount (8 μl mgsulfur-1). While the capacity retention over 50 cycles is identical to a cell with high excess lithium anode, the volumetric energy density could be increased by 30%.

  17. A modified approach to actively remove high viscosity silicone oil through 23-gauge cannula.

    Science.gov (United States)

    Song, Zong-Ming; Hu, Xu-Ting; Wang, Lei; Hu, Zhi-Xiang; Zhao, Pei-Quan; Chen, Ding

    2016-01-01

    To report a simple approach to actively remove high viscosity silicone oil through a 23-gauge cannula via pars plana. Forty-eight eyes of 48 patients underwent silicone oil (5700 centistokes) removal (SOR) were enrolled. A section of blood transfusion set was prepared to connect a standard 23-gauge cannula and vitrectomy machine. Silicone oil was removed with suction of 500-mm Hg vacuum through the cannula. Main outcome measures were SOR duration, number of sutured sites, intraocular pressure (IOP), best-corrected visual acuity (BCVA), and complications. Silicone oil was successfully removed in all cases. The mean SOR time was 5.70±0.85min. Nine eyes (18.75%) needed suture partial sclerotomies. No intraoperative complications were noted. Transient hypotony (≤8 mm Hg) was seen in 3 eyes (6.25%) on postoperative day 1, but all resolved within 1wk. Retinal reattachment was achieved in all cases and no other postoperative complications were noted during 3-month following-up. BCVA at the final visit improved or stabilized in all patients comparing to the preoperative level. Active removal of high viscosity silicone oil through a 23-gauge instrument cannula jointed with blood transfusion set is a practical and reliable technique when considering two sides of efficacy and safety.

  18. Novel Ag-doped glass frits for high-efficiency crystalline silicon solar cells.

    Science.gov (United States)

    Yuan, Sheng; Chen, Yongji; Mei, Zongwei; Zhang, Ming-Jian; Gao, Zhou; Wang, Xingbo; Jiang, Xing; Pan, Feng

    2017-06-06

    Glass frits play an important role in the front contact electrodes of crystalline silicon (c-Si) solar cells. In this work, we developed a novel glass frit by doping Ag into a glass frit in the process of high-temperature synthesis. When the Ag paste including this novel glass frit was used as the front contact electrode of silicon solar cells, the conversion efficiency of poly-crystalline silicon (pc-Si) solar cells was improved by 1.9% compared to the glass frit without Ag. Through SEM characterisation and calculation of series resistance, we further found that the interface between Ag and Si was improved and the contact resistance of Ag and Si was greatly reduced, which were believed to be responsible for the improvement of solar cell performance. This work shows great guidance significance to develop novel and highly efficient commercial glass frits applied in solar cells in the future.

  19. An Investigation of High Performance Heterojunction Silicon Solar Cell Based on n-type Si Substrate

    Directory of Open Access Journals (Sweden)

    N. Memarian

    2016-12-01

    Full Text Available In this study, high efficient heterojunction crystalline silicon solar cells without using an intrinsic layer were systematically investigated. The effect of various parameters such as work function of transparent conductive oxide (ϕTCO, density of interface defects, emitter and crystalline silicon thickness on heterojunction silicon solar cell performance was studied. In addition, the effect of band bending and internal electric field on solar cell performance together with the dependency of cell performance on work function and reflectance of the back contact were investigated in full details. The optimum values of the solar cell properties for the highest efficiency are presented based on the results of the current study. The results represent a complete set of optimum values for a heterojunction solar cell with high efficiency up to the 24.1 % with VOC  0.87 V and JSC  32.69 mAcm – 2.

  20. High-density G-centers, light-emitting point defects in silicon crystal

    Directory of Open Access Journals (Sweden)

    Koichi Murata

    2011-09-01

    Full Text Available We propose a new method of creating light-emitting point defects, or G-centers, by modifying a silicon surface with hexamethyldisilazane followed by laser annealing of the surface region. This laser annealing process has two advantages: creation of highly dense G-centers by incorporating carbon atoms into the silicon during heating; freezing in the created G-centers during rapid cooling. The method provides a surface region of up to 200 nm with highly dense carbon atoms of up to 4 × 1019 cm−3 to create G-centers, above the solubility limit of carbon atoms in silicon crystal (3 × 1017 cm−3. Photoluminescence measurement reveals that the higher-speed laser annealing produces stronger G-center luminescence. We demonstrate electrically-driven emission from the G-centers in samples made using our new method.

  1. Quality of silicon convex lenses fabricated by ultra-high precision diamond machining

    Directory of Open Access Journals (Sweden)

    Abou-El-Hossein, K.

    2013-05-01

    Full Text Available Infra-red optical components are made mainly from hard and brittle materials such as germanium and silicon. Silicon machining is characterised by some difficulties when ultra-high precision machined by mono-crystalline single-point diamond. Accelerated tool wear and machined-surface deterioration may take place if the machining parameters are not properly selected. In this study, we conducted a machining test on an ultra-high precision machine tool, using ductile regime cutting conditions when fabricating a convex surface on a silicon lens of aperture of 60 mm diameter, and using a mono-crystalline diamond. It was found that the cutting conditions for shaping a convex surface of 500 mm radius resulted in good form accuracy. However, more attention should be paid to optimising the holding force of the vacuum chuck employed.

  2. High-pressure synthesis at the origin of new developments in silicon clathrate physical chemistry

    CERN Document Server

    Reny, E; Cros, C; Pouchard, M

    2002-01-01

    Since their discovery in 1965, various compositions of clathrate phases of silicon have been investigated and have revealed a direct correlation between the doping element and their properties. The recent development of a new synthesis technique using high-pressure and high-temperature (HPHT) conditions allows the synthesis of peculiar clathrate compositions which can show fascinating properties, such as Ba sub 8 Si sub 4 sub 6 which is a sp sup 3 silicon-based structure with superconducting characteristics. This work reports the synthesis of the first binary silicon clathrate doped with an electronegative element and prepared using HPHT: I sub 8 Si sub 4 sub 6 sub sub - sub x I sub x. Some chemical and structural results are also presented.

  3. High-pressure synthesis at the origin of new developments in silicon clathrate physical chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Reny, Edouard [Department of Applied Chemistry, Faculty of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan); Yamanaka, S [Department of Applied Chemistry, Faculty of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan); Cros, C [Institut de Chimie de la Matiere Condensee de Bordeaux, UPR/CNRS 9048, 33608 Pessac (France); Pouchard, M [Institut de Chimie de la Matiere Condensee de Bordeaux, UPR/CNRS 9048, 33608 Pessac (France)

    2002-11-11

    Since their discovery in 1965, various compositions of clathrate phases of silicon have been investigated and have revealed a direct correlation between the doping element and their properties. The recent development of a new synthesis technique using high-pressure and high-temperature (HPHT) conditions allows the synthesis of peculiar clathrate compositions which can show fascinating properties, such as Ba{sub 8}Si{sub 46} which is a sp{sup 3} silicon-based structure with superconducting characteristics. This work reports the synthesis of the first binary silicon clathrate doped with an electronegative element and prepared using HPHT: I{sub 8}Si{sub 46-x}I{sub x}. Some chemical and structural results are also presented.

  4. Controlling light with high-Q silicon photonic crystal nanocavities: Photon confinement, nonlinearity and coherence

    Science.gov (United States)

    Yang, Xiaodong

    The strong light localization and long photon lifetimes in two-dimensional silicon photonic crystal nanocavities with high quality factor (Q ) and subwavelength modal volume (V) significantly enhance the light-matter interactions, presenting many opportunities to explore new functionalities in silicon nanophotonic integrated circuits for on-chip all-optical information processing, optical computation and optical communications. This thesis will focus on the design, nanofabrication, and experimental characterization of both passive and active silicon nanophotonic devices based on two-dimensional high-Q silicon photonic crystal nanocavities. Three topics of controlling light with these high-Q nanocavities will be presented, including (1) photon confinement mechanism and cavity resonance tuning, (2) enhancement of optical nonlinearities, and (3) all-optical analogue to coherent interferences. The first topic is photon confinement in two-dimensional high- Q silicon photonic crystal nanocavities. In Chapter 2, the role of Q/V as the figure of merit for the enhanced light-matter interaction in optical microcavities and nanocavities is explained and different types of high-Q optical microcavities and nanocavities are reviewed with an emphasis on two-dimensional photonic crystal nanocavities. Then the nanofabrication process and the Q characterization are illustrated for the two-dimensional silicon photonic crystal nanocavities. In Chapter 3, the post-fabrication digital resonance tuning of high-Q silicon photonic crystal nanocavities using atomic layer deposition is proposed and demonstrated, with wide tuning range and precise control of cavity resonances while preserving high quality factors. The second topic is the enhancement of optical nonlinearities in two-dimensional high-Q silicon photonic crystal nanocavities, including stimulated Raman scattering and thermo-optical nonlinearities. In Chapter 4, the enhanced stimulated Raman scattering for low threshold Raman

  5. The convergent and discriminant validity of burnout measures in sport: a multi-trait/multi-method analysis.

    Science.gov (United States)

    Cresswell, Scott L; Eklund, Robert C

    2006-02-01

    Athlete burnout research has been hampered by the lack of an adequate measurement tool. The Athlete Burnout Questionnaire (ABQ) and the Maslach Burnout Inventory General Survey (MBI-GS) are two recently developed self-report instruments designed to assess burnout. The convergent and discriminant validity of the ABQ and MBI-GS were assessed through multi-trait/multi-method analysis with a sporting population. Overall, the ABQ and the MBI-GS displayed acceptable convergent validity with matching subscales highly correlated, and satisfactory internal discriminant validity with lower correlations between non-matching subscales. Both scales also indicated an adequate discrimination between the concepts of burnout and depression. These findings add support to previous findings in non-sporting populations that depression and burnout are separate constructs. Based on the psychometric results, construct validity analysis and practical considerations, the results support the use of the ABQ to assess athlete burnout.

  6. EMOTIONAL BURNOUT SYNDROME: EFFECT ON CLINICAL INERTIA AND MEDICAL PRACTICE STEREOTYPES

    Directory of Open Access Journals (Sweden)

    R. A. Khokhlov

    2009-01-01

    Full Text Available Aim. To estimate the prevalence of burnout in primary care physicians and its influence on medical practice stereotypes and on clinical inertia.Material and Methods. The anonymous single-stage poll was carried out among 184 primary care physicians. The questionnaire included information about sex, age, period and conditions of work, established stereotypes of practices. Burnout was evaluated by Russian analog of Maslach Burnout Inventory. It was defined in high level of emotional exhaustion and depersonalization and low level of personal accomplishment 11 questions were developed to reveal of suboptimal medical practice (for example, “I do not discuss treatment options with patient and do not give full answers to his questions” or “I make diagnostic and treatment errors despite of my professional knowledge and inexperience”.Results. The burnout syndrome (or extreme grade of emotional burnout occurs in 13,1% and high level of emotional burnout – in 49,7% of primary care physicians. Features of suboptimal medical practice are usually found in 24,2% of primary care physicians at least monthly. It expresses more often in improper attitude to paqtients and their problems associated with a disease. Thus, burnout contributes to improper attitude to patients. Professional burnout affects established work stereotypes and can promote development of physician’s clinical inertia.Conclusion. As the burnout is common among primary care physicians, an adequate monitoring and prevention of this state is necessary in medical labour management.

  7. The association between social capital and burnout in nurses of a trauma referral teaching hospital.

    Science.gov (United States)

    Farahbod, Farzin; Goudarzvand Chegini, Mehrdad; Kouchakinejad Eramsadati, Leila; Mohtasham-Amiri, Zahra

    2015-01-01

    Social capital is a multi-faceted phenomenon in social sciences that massively affects many social fields. It can be a helpful factor in promoting health. Among the groups with high burnout, nurses have always shown higher levels of burnout. Studies have revealed that social capital can be an important factor affecting burnout. This study aimed to determine the extent of the effect of social capital on burnout in nurses of a trauma referral teaching hospital in Rasht. This was a descriptive correlational study conducted on 214 nurses of a trauma referral teaching hospital. Maslach standard questionnaire and the social capital questionnaire devised by Boyas and colleagues were used. Data were analyzed using descriptive statistics, Pearson correlation coefficient, and linear regression analysis to determine the extent of the effect of social capital on burnout. The study showed an inverse association between social capital and burnout. The intensity of the relationship was -0.451 (Pburnout variable showed that the regression coefficient of social capital equaled -0.34. The determination coefficient of this regression model indicated that social capital explained 20% of burnout changes. The results showed high burnout in emotional exhaustion dimension and an inverse association between social capital and burnout. Thus, attempts should be made to promote social capital dimensions among nurses. Given the inevitability of job stress in a nursing environment, and managers should plan on improving the working conditions and training techniques to deal with such stress.

  8. The effects of personality traits on academic burnout in Korean medical students.

    Science.gov (United States)

    Lee, Soo Jin; Choi, Young Jun; Chae, Han

    2017-06-01

    Previous studies suggest that personality traits play an important role in academic burnout. The aim of this study was to investigate how Cloninger's temperament and character traits explain academic burnout in a highly competitive environment of medical school. A total of 184 Korean medical students participated in the survey. The Cloninger's Temperament and Character Inventory was measured around the beginning of the semester and Maslach Burnout Inventory-Student Survey at the end of the semester. The correlations and stepwise regression analysis were conducted to explain the association between personality traits and academic burnout. In addition, latent profile analysis and profile analysis were employed to distinguish and explain differences of personality traits among latent academic burnout subgroups. The higher harm avoidance of temperament and lower self-directedness and cooperativeness of character predicted the subscales of academic burnout in medical students. The Temperament and Character Inventory personality profile of high, middle, and low latent burnout subgroups were significantly different. This study showed that personality might account for the burnout level in medical education. The importance of character dimension for modulating the effects of temperament traits on academic burnout was discussed for future research.

  9. Job-related burnout among juvenile probation officers: Implications for mental health stigma and competency.

    Science.gov (United States)

    White, Laura M; Aalsma, Matthew C; Holloway, Evan D; Adams, Erin L; Salyers, Michelle P

    2015-08-01

    The high demands and responsibilities of probation work, particularly with juvenile clients, may lead to burnout, which can negatively impact how probation officers work with clients, particularly individuals with behavioral health concerns. Yet, research examining burnout and related outcomes among juvenile probation officers (JPOs) is limited. We surveyed 246 JPOs in a Midwestern state to identify the prevalence, predictors, and potential outcomes of burnout. JPOs reported moderate levels of burnout; about 30% of the sample scored in the high range for emotional exhaustion and cynicism. Contrary to study hypotheses, there were no group-level differences in burnout scores across gender, race/ethnicity, age, or education. In regression models, burnout was predicted by being White (vs. minority), serving in an urban (vs. rural) county, dissatisfaction with department guidelines, job dissatisfaction, viewing job role as more treatment-oriented along the enforcement-treatment continuum, and turnover intention. JPOs with burnout were more likely to endorse mental health stigma and lack of mental health competency to address juvenile clients with behavioral health concerns. Findings suggest burnout prevention and intervention programs should be considered for JPOs to increase job satisfaction, limit job turnover, reduce burnout, and possibly increase effective practices for managing juvenile clients with behavioral health needs.

  10. EMOTIONAL BURNOUT SYNDROME: EFFECT ON CLINICAL INERTIA AND MEDICAL PRACTICE STEREOTYPES

    Directory of Open Access Journals (Sweden)

    R. A. Khokhlov

    2016-01-01

    Full Text Available Aim. To estimate the prevalence of burnout in primary care physicians and its influence on medical practice stereotypes and on clinical inertia.Material and Methods. The anonymous single-stage poll was carried out among 184 primary care physicians. The questionnaire included information about sex, age, period and conditions of work, established stereotypes of practices. Burnout was evaluated by Russian analog of Maslach Burnout Inventory. It was defined in high level of emotional exhaustion and depersonalization and low level of personal accomplishment 11 questions were developed to reveal of suboptimal medical practice (for example, “I do not discuss treatment options with patient and do not give full answers to his questions” or “I make diagnostic and treatment errors despite of my professional knowledge and inexperience”.Results. The burnout syndrome (or extreme grade of emotional burnout occurs in 13,1% and high level of emotional burnout – in 49,7% of primary care physicians. Features of suboptimal medical practice are usually found in 24,2% of primary care physicians at least monthly. It expresses more often in improper attitude to paqtients and their problems associated with a disease. Thus, burnout contributes to improper attitude to patients. Professional burnout affects established work stereotypes and can promote development of physician’s clinical inertia.Conclusion. As the burnout is common among primary care physicians, an adequate monitoring and prevention of this state is necessary in medical labour management.

  11. The impact of empathy on burnout in medical students: new findings.

    Science.gov (United States)

    von Harscher, Heidi; Desmarais, Nathaly; Dollinger, Robert; Grossman, Seth; Aldana, Scarlett

    2017-09-28

    Research on medical students has shown they are at a higher risk for burnout and that this burnout may become more prevalent as they advance in medical school. The literature, thus far, has not explored the construct of ,emotional empathy and whether this can impact burnout in medical students. Objective: To understand the relationship  between empathy (Empathic Concern [EC] and Personal Distress [PD]) and burnout in medical students. Five successive classes of medical students enrolled at a new medical school were given the Maslach Burnout Inventory and Davis' Interpersonal Reactivity Index  over the course of three successive  years (n = 353).  Two dimensions of  empathy were evaluated to determine if they have an impact on three dimensions of burnout (Emotional Exhaustion/EE, Depersonalization/DP, Personal Accomplishment/PA). data was analyzed using a linear mixed model for each of the three components of burnout based on gender, age, year in medical school, and two types of empathy: EC, and PD.  Conclusion: It was discovered that students with high levels of EC had statistically lower scores of burnout over time while students with high levels of PD empathy showed statistically higher scores of burnout over three years. Implications for these findings are discussed.

  12. Assessing coal burnout

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, A. [Pacific Power, Sydney, NSW (Australia)

    1999-11-01

    Recent research has allowed a quantitative description of the basic process of burnout for pulverized coals to be made. The Cooperative Research Centre for Black Coal Utilization has built on this work to develop a coal combustion model which will allow plant engineers and coal company representatives to assess their coals for combustion performance. The paper describes the model and its validation and outlines how it is run. 2 figs.

  13. Rekindling the Flame: Principals Combating Teacher Burnout.

    Science.gov (United States)

    Brock, Barbara L.; Grady, Marilyn L.

    This book offers a research-based, practical approach to recognizing, managing, and preventing teacher burnout. It provides a description of the origins and symptoms of burnout and a personality profile of teachers who are most susceptible to burnout. Organizational issues and administrative roles that contribute to burnout are identified, along…

  14. Highly Manufacturable Deep (Sub-Millimeter) Etching Enabled High Aspect Ratio Complex Geometry Lego-Like Silicon Electronics

    KAUST Repository

    Ghoneim, Mohamed T.

    2017-02-01

    A highly manufacturable deep reactive ion etching based process involving a hybrid soft/hard mask process technology shows high aspect ratio complex geometry Lego-like silicon electronics formation enabling free-form (physically flexible, stretchable, and reconfigurable) electronic systems.

  15. High Reflectance Silicon Dielectric Mirrors for Infrared Astronomy Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Conventional high reflectance optical coatings consisting of multilayer stacks of alternating high and low refractive index dielectric materials can achieve high...

  16. One step lithography-less silicon nanomanufacturing for low cost high-efficiency solar cell production

    Science.gov (United States)

    Chen, Yi; Liu, Logan

    2014-03-01

    To improve light absorption, previously various antireflection material layers were created on solar wafer surface including multilayer dielectric film, nanoparticle sludges, microtextures, noble metal plasmonic nanoparticles and 3D silicon nanostructure arrays. All of these approaches involve nanoscale prepatterning, surface-area-sensitive assembly processes or extreme fabrication conditions; therefore, they are often limited by the associated high cost and low yield as well as the consequent industry incompatibility. In comparison, our nanomanufacturing, an unique synchronized and simultaneous top-down and bottom-up nanofabrication approach called simultaneous plasma enhanced reactive ion synthesis and etching (SPERISE), offers a better antireflection solution along with the potential to increase p-n junction surface area. High density and high aspect ratio anechoic nanocone arrays are repeatedly and reliably created on the entire surface of single and poly crystalline silicon wafers as well as amorphous silicon thin films within 5 minutes under room temperature. The nanocone surface had lower than 5% reflection over the entire solar spectrum and a desirable omnidirectional absorption property. Using the nanotextured solar wafer, a 156mm × 156mm 18.1%-efficient black silicon solar cell was fabricated, which was an 18.3% enhancement over the cell fabricated by standard industrial processes. This process also reduces silicon loss during the texturing step and enables tighter process control by creating more uniform surface structures. Considering all the above advantages, the demonstrated nanomanufacturing process can be readily translated into current industrial silicon solar cell fabrication lines to replace the costly and ineffective wet chemical texturing and antireflective coatings.

  17. High temperature C/C–SiC composite by liquid silicon infiltration: a literature review

    Indian Academy of Sciences (India)

    Manish Patel; Kumar Saurabh; V V Bhanu Prasad; J Subrahmanyam

    2012-02-01

    The ceramic matrix carbon fibre (CMC) reinforced composite has received great attention for use in aerospace engineering. In aerospace, the atmosphere is highly oxidative and experiences very high temperature. In addition to this, the materials require high thermal stability and high abrasion resistance in that atmosphere. The C/C–SiC composite meets with these requirements. In this paper, the C/C–SiC composite by liquid silicon infiltration is reviewed thoroughly.

  18. Can the existing knowledge in depression treatment aid the recovery from the burnout syndrome?

    DEFF Research Database (Denmark)

    Macoveanu, Julian

    2016-01-01

    Due to high levels of stress in many professions today, an increasing number of people experience a state of emotional, mental, and physical exhaustion referred to as the burnout syndrome. The neural underpinnings of the burnout syndrome remain however poorly understood. This highly timely topic...

  19. Thermodynamic Calculations of Melt in Melt Pool During Laser Cladding High Silicon Coatings

    Institute of Scientific and Technical Information of China (English)

    DONG Dan-yang; LIU Chang-sheng; ZHANG Bin

    2008-01-01

    Based on the Miedema's formation heat model for binary alloys and the Toop's asymmetric model for terna-ry alloys, the formation heat, excess entropy, and activity coefficients of silicon ranging from 1 900 K to 4 100 K in the Fe-Si-C melt formed during the laser cladding high silicon coatings process were calculated. The results indicated that all values of InγOSi, εCSi, ρSiSi and ρCSi are negative in the temperature range and these values increase as the tempera-ture increases. And all values of εSiSi and ρSi-CSi are positive and these values decrease with increasing temperature. The iso-activity lines of silicon are distributed axisymmetrically to the incident laser beam in the melt pool vertical to the laser scanning direction. And the iso-activity lines of silicon in the front of the melt pool along the laser scanning direction are more intensive than those in the back of the melt pool. The activity of silicon on the bottom of the melt pool is lower than that in the effecting center of laser beam on the top surface of the melt pool and it may be the im-portant reason for the formation of the silicides and excellent metallurgical bonding between the laser cladding coating and the substrate.

  20. Plastic Deformation of Micromachined Silicon Diaphragms with a Sealed Cavity at High Temperatures

    Directory of Open Access Journals (Sweden)

    Juan Ren

    2016-02-01

    Full Text Available Single crystal silicon (SCS diaphragms are widely used as pressure sensitive elements in micromachined pressure sensors. However, for harsh environments applications, pure silicon diaphragms are hardly used because of the deterioration of SCS in both electrical and mechanical properties. To survive at the elevated temperature, the silicon structures must work in combination with other advanced materials, such as silicon carbide (SiC or silicon on insulator (SOI, for improved performance and reduced cost. Hence, in order to extend the operating temperatures of existing SCS microstructures, this work investigates the mechanical behavior of pressurized SCS diaphragms at high temperatures. A model was developed to predict the plastic deformation of SCS diaphragms and was verified by the experiments. The evolution of the deformation was obtained by studying the surface profiles at different anneal stages. The slow continuous deformation was considered as creep for the diaphragms with a radius of 2.5 mm at 600 °C. The occurrence of plastic deformation was successfully predicted by the model and was observed at the operating temperature of 800 °C and 900 °C, respectively.

  1. High-efficiency deflection of high energy protons due to channeling along the axis of a bent silicon crystal

    Science.gov (United States)

    Scandale, W.; Arduini, G.; Butcher, M.; Cerutti, F.; Garattini, M.; Gilardoni, S.; Lechner, A.; Masi, A.; Mirarchi, D.; Montesano, S.; Redaelli, S.; Rossi, R.; Smirnov, G.; Breton, D.; Burmistrov, L.; Chaumat, V.; Dubos, S.; Maalmi, J.; Puill, V.; Stocchi, A.; Bagli, E.; Bandiera, L.; Germogli, G.; Guidi, V.; Mazzolari, A.; Dabagov, S.; Murtas, F.; Addesa, F.; Cavoto, G.; Iacoangeli, F.; Galluccio, F.; Afonin, A. G.; Chesnokov, Yu. A.; Durum, A. A.; Maisheev, V. A.; Sandomirskiy, Yu. E.; Yanovich, A. A.; Kovalenko, A. D.; Taratin, A. M.; Denisov, A. S.; Gavrikov, Yu. A.; Ivanov, Yu. M.; Lapina, L. P.; Malyarenko, L. G.; Skorobogatov, V. V.; James, T.; Hall, G.; Pesaresi, M.; Raymond, M.

    2016-09-01

    A deflection efficiency of about 61% was observed for 400 GeV/c protons due to channeling, most strongly along the axis of a bent silicon crystal. It is comparable with the deflection efficiency in planar channeling and considerably larger than in the case of the axis. The measured probability of inelastic nuclear interactions of protons in channeling along the axis is only about 10% of its amorphous level whereas in channeling along the (110) planes it is about 25%. High efficiency deflection and small beam losses make this axial orientation of a silicon crystal a useful tool for the beam steering of high energy charged particles.

  2. Ultra-high cell-density silicon photomultipliers with high detection efficiency

    Science.gov (United States)

    Acerbi, Fabio; Gola, Alberto; Regazzoni, Veronica; Paternoster, Giovanni; Borghi, Giacomo; Piemonte, Claudio; Zorzi, Nicola

    2017-05-01

    Silicon photomultipliers (SiPMs) are arrays of many single-photon avalanche diodes (SPADs), all connected in parallel. Each SPAD is sensitive to single photons and the SiPM gives an output proportional to the number of detected photons. These sensors are becoming more and more popular in different applications, from high-energy physics to spectroscopy, and they have been significantly improved over last years, decreasing the noise, increasing the cell fill-factor (FF) and thus achieving very high photon-detection efficiency (PDE). In FBK (Trento, Italy), we developed new SiPM technologies with high-density (HD) and, more recently, ultra-high-density (UHD) of cells (i.e. density of SPADs). These technologies employ deep-trenches between cells, for electrical and optical isolation. As an extreme case the smallest-cell, SiPM, i.e. with 5μm cell pitch, has about 40000 SPADs per squared millimeter. Such small SPAD dimensions gives a significantly high dynamic range to the SiPM. These small-cells SiPM have a lower correlated noise (including lower afterpulsing probability) and a faster recharge time (in the order of few nanoseconds), and they also preserve a very good detection efficiency (despite the small SPAD dimension).

  3. Burnout in Gerontological Social Work.

    Science.gov (United States)

    Poulin, John E.; Walter, Carolyn A.

    1993-01-01

    Conducted national survey of burnout among 1,196 social workers who work with elderly people. Examined extent to which workers experienced emotional exhaustion, depersonalization, and personal accomplishment. Found that levels of gerontological social workers' burnout appeared lower than levels found among social workers in child welfare, mental…

  4. Burnout : de stand van zaken

    NARCIS (Netherlands)

    Taris, T.; Houtman, I.L.D.; Schaufeli, W.

    2013-01-01

    Dit artikel geeft een overzicht van de stand van zaken in het onderzoek naar burnout. Burnout is een syndroom van extreme vermoeidheid (uitputting), afstand nemen van het werk (distantie) en weinig vertrouwen in het eigen kunnen (verminderde competentie), waarbij de oorzaken voor deze aspecten geleg

  5. EEG Findings in Burnout Patients

    NARCIS (Netherlands)

    Luijtelaar, E.L.J.M. van; Verbraak, M.J.P.M.; Bunt, P.M. van den; Keijsers, G.P.J.; Arns, M.W.

    2010-01-01

    The concept of burnout remains enigmatic since it is only determined by behavioral characteristics. Moreover, the differential diagnosis with depression and chronic fatigue syndrome is difficult. EEG-related variables in 13 patients diagnosed with burnout syndrome were compared with 13 healthy

  6. EEG Findings in Burnout Patients

    NARCIS (Netherlands)

    Luijtelaar, E.L.J.M. van; Verbraak, M.J.P.M.; Bunt, P.M. van den; Keijsers, G.P.J.; Arns, M.W.

    2010-01-01

    The concept of burnout remains enigmatic since it is only determined by behavioral characteristics. Moreover, the differential diagnosis with depression and chronic fatigue syndrome is difficult. EEG-related variables in 13 patients diagnosed with burnout syndrome were compared with 13 healthy compa

  7. Burnout : de stand van zaken

    NARCIS (Netherlands)

    Taris, T.; Houtman, I.L.D.; Schaufeli, W.

    2013-01-01

    Dit artikel geeft een overzicht van de stand van zaken in het onderzoek naar burnout. Burnout is een syndroom van extreme vermoeidheid (uitputting), afstand nemen van het werk (distantie) en weinig vertrouwen in het eigen kunnen (verminderde competentie), waarbij de oorzaken voor deze aspecten

  8. Recoil implantation of boron into silicon by high energy silicon ions

    Science.gov (United States)

    Shao, L.; Lu, X. M.; Wang, X. M.; Rusakova, I.; Mount, G.; Zhang, L. H.; Liu, J. R.; Chu, Wei-Kan

    2001-07-01

    A recoil implantation technique for shallow junction formation was investigated. After e-gun deposition of a B layer onto Si, 10, 50, or 500 keV Si ion beams were used to introduce surface deposited B atoms into Si by knock-on. It has been shown that recoil implantation with high energy incident ions like 500 keV produces a shallower B profile than lower energy implantation such as 10 keV and 50 keV. This is due to the fact that recoil probability at a given angle is a strong function of the energy of the primary projectile. Boron diffusion was showed to be suppressed in high energy recoil implantation and such suppression became more obvious at higher Si doses. It was suggested that vacancy rich region due to defect imbalance plays the role to suppress B diffusion. Sub-100 nm junction can be formed by this technique with the advantage of high throughput of high energy implanters.

  9. Memory effects in metal-oxide-semiconductor capacitors incorporating dispensed highly monodisperse 1 nm silicon nanoparticles

    Science.gov (United States)

    Nayfeh, Osama M.; Antoniadis, Dimitri A.; Mantey, Kevin; Nayfeh, Munir H.

    2007-04-01

    Metal-oxide-semiconductor capacitors containing various densities of ex situ produced, colloidal, highly monodisperse, spherical, 1nm silicon nanoparticles were fabricated and evaluated for potential use as charge storage elements in future nonvolatile memory devices. The capacitance-voltage characteristics are well behaved and agree with similarly fabricated zero-nanoparticle control samples and with an ideal simulation. Unlike larger particle systems, the demonstrated memory effect exhibits effectively pure hole storage. The nature of charging, hole type versus electron type may be understood in terms of the characteristics of ultrasmall silicon nanoparticles: large energy gap, large charging energy, and consequently a small electron affinity.

  10. Silicon as anode for high-energy lithium ion batteries: From molten ingot to nanoparticles

    Science.gov (United States)

    Leblanc, Dominic; Hovington, Pierre; Kim, Chisu; Guerfi, Abdelbast; Bélanger, Daniel; Zaghib, Karim

    2015-12-01

    In this work, we demonstrate that a new mechanical attrition process can be used to prepare nanosilicon powder from metallurgical grade silicon lumps. Composite Li-ion anode made from this nanometer-size powder was found to have a high reversible capacity of 2400 mAh g-1 and an improved cycling stability compared to micrometer-sized powder. It is proposed that improved battery cycling performance is ascribed to the nanoscale silicon particles which supresses the volume expansion owing to its superplasticity.

  11. Interface Engineering of High Efficiency Organic-Silicon Heterojunction Solar Cells.

    Science.gov (United States)

    Yang, Lixia; Liu, Yaoping; Chen, Wei; Wang, Yan; Liang, Huili; Mei, Zengxia; Kuznetsov, Andrej; Du, Xiaolong

    2016-01-13

    Insufficient interface conformity is a challenge faced in hybrid organic-silicon heterojunction solar cells because of using conventional pyramid antireflection texturing provoking the porosity of interface. In this study, we tested alternative textures, in particular rounded pyramids and inverted pyramids to compare the performance. It was remarkably improved delivering 7.61%, 8.91% and 10.04% efficiency employing conventional, rounded, and inverted pyramids, respectively. The result was interpreted in terms of gradually improving conformity of the Ag/organic/silicon interface, together with the gradually decreasing serial resistance. Altogether, the present data may guide further efforts arising the interface engineering for mastering high efficient heterojunction solar cells.

  12. Selective tuning of high-Q silicon photonic crystal nanocavities via laser-assisted local oxidation

    CERN Document Server

    Chen, Charlton J; Gu, Tingyi; McMillan, James F; Yu, Mingbin; Lo, Guo-Qiang; Kwong, Dim-Lee; Wong, Chee Wei

    2011-01-01

    We examine the cavity resonance tuning of high-Q silicon photonic crystal heterostructures by localized laser-assisted thermal oxidation using a 532 nm continuous wave laser focused to a 2.5 mm radius spot-size. The total shift is consistent with the parabolic rate law. A tuning range of up to 8.7 nm is achieved with ~ 30 mW laser powers. Over this tuning range, the cavity Q decreases from 3.2\\times10^5 to 1.2\\times10^5. Numerical simulations model the temperature distributions in the silicon photonic crystal membrane and the cavity resonance shift from oxidation.

  13. High-resolution tracking with silicon strip detectors for relativistic ions

    CERN Document Server

    Hou, S R; Ambrosi, G; Balboni, C; Battiston, R; Burger, W J; Chang, Y H; Geissel, H; Ionica, M; Lustermann, W; Maehlum, G; Menichelli, M; Pauluzzi, M; Postolache, V; Produit, N; Rapin, D; Ren, D; Ribordy, M; Sann, H; Schardt, D; Sümmerer, K; Viertel, Gert M

    1999-01-01

    Tracking with silicon strip detectors for relativistic ions has been investigated using a sup 1 sup 2 C beam of 1.5 GeV/u at GSI. The ionization charge spectrum and the charge sharing between strips are presented. The strip cluster of carbon ion can be selected based on the cluster charge with high efficiency and little contamination. The spatial resolution of the silicon strip detectors is evaluated. The angular distribution of multiple Coulomb scattering was investigated with lead absorbers. The results are compared to the Moliere theory and the Gaussian approximation of GEANT calculations. (author)

  14. Controlled fabrication of individual silicon quantum rods yielding high intensity, polarized light emission

    Science.gov (United States)

    Bruhn, Benjamin; Valenta, Jan; Linnros, Jan

    2009-12-01

    Elongated silicon quantum dots (also referred to as rods) were fabricated using a lithographic process which reliably yields sufficient numbers of emitters. These quantum rods are perfectly aligned and the vast majority are spatially separated well enough to enable single-dot spectroscopy. Not only do they exhibit extraordinarily high linear polarization with respect to both absorption and emission, but the silicon rods also appear to luminesce much more brightly than their spherical counterparts. Significantly increased quantum efficiency and almost unity degree of linear polarization render these quantum rods perfect candidates for numerous applications.

  15. Defects in Fast-Neutron Irradiated Nitrogen-Doped Czochralski Silicon after Annealing at High Temperature

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Fast-neutron irradiated nitrogen-doped Czochralski silicon (NCZ-Si) was annealed at 1100 ℃ for different time, then FTIR and optical microscope were used to study the behavior of oxygen. It is found that [Oi] increase at the early stage then decrease along with the increasing of anneal time. High density induced-defects can be found in the cleavage plane. By comparing NCZ-Si with Czochralski silicon (CZ-Si), [Oi] in NCZ-Si decrease more after anneal 24 h.

  16. Preparation of silicon carbide nitride films on Si substrate by pulsed high-energy density plasma

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Thin films of silicon carbide nitride (SiCN) were prepared on (111) oriented silicon substrates by pulsed high-energy density plasma (PHEDP). The evolution of the chemical bonding states between silicon, nitrogen and carbon was investigated as a function of discharge voltage using X-ray photoelectron spectroscopy. With an increase in discharge voltage both the C1s and N 1s spectra shift to lower binding energy due to the formation of C-Si and N-Si bonds. The Si-C-N bonds were observed in the deconvolved C1s and N 1s spectra. The X-ray diffractometer (XRD) results show that there were no crystals in the films. The thickness of the films was approximately 1-2 μm with scanning electron microscopy (SEM).

  17. High resolution Laplace DLTS studies of defects in ion-implanted silicon

    Energy Technology Data Exchange (ETDEWEB)

    Evans-Freeman, J.H. E-mail: j.evans-freeman@umist.ac.uk; Abdelgader, N.; Kan, P.Y.Y.; Peaker, A.R

    2002-01-01

    We have used high resolution Laplace deep level transient spectroscopy (LDLTS) to investigate defects in n-type silicon caused by implantation of Si, Ge or Er with doses of the order of 1x10{sup 9} cm{sup -2}. These are compared with defects created in proton irradiated n-type silicon. Unlike the simple proton irradiated case, LDLTS spectra of ion implanted silicon show that there are many emission rates associated with defects with energies in the region of E{sub c}-400 meV. We have carried out annealing studies and Laplace DLTS depth profiling and show that the complex spectra measured from a region less than half way through the implant simplify as the profile is moved through the implant and towards the tail. Annealing studies show that these defects survive an anneal that should remove the E-centre.

  18. Gas phase considerations for the growth of device quality nanocrystalline silicon at high rate

    NARCIS (Netherlands)

    Rath, J.K.; Verkerk, A.D.; Liu, Y.; Brinza, M.; Goedheer, W.J.; Schropp, R.E.I.

    2008-01-01

    In order to increase industrial viability and to find niche markets, high deposition rate and low temperature depositions compared to standard deposition conditions are two recent trends in research areas concerning thin film silicon. In situ diagnostic tools to monitor gas phase conditions are usef

  19. Gas phase considerations for the growth of device quality nanocrystalline silicon at high rate

    NARCIS (Netherlands)

    J.K. Rath,; Verkerk, A. D.; Liu, Y.; Brinza, M.; W. J. Goedheer,; Schropp, R. E. I.

    2009-01-01

    In order to increase industrial viability and to find niche markets, high deposition rate and low temperature depositions compared to standard deposition conditions are two recent trends in research areas concerning thin film silicon. In situ diagnostic tools to monitor gas phase conditions are usef

  20. Silicon nitride at high growth rate using hot wire chemical vapor deposition

    NARCIS (Netherlands)

    Verlaan, V.

    2008-01-01

    Amorphous silicon nitride (SiNx) is a widely studied alloy with many commercial applications. This thesis describes the application of SiNx deposited at high deposition rate using hot wire chemical vapor deposition (HWCVD) for solar cells and thin film transistors (TFTs). The deposition process of H

  1. Silicon nitride at high growth rate using hot wire chemical vapor deposition

    NARCIS (Netherlands)

    Verlaan, V.

    2008-01-01

    Amorphous silicon nitride (SiNx) is a widely studied alloy with many commercial applications. This thesis describes the application of SiNx deposited at high deposition rate using hot wire chemical vapor deposition (HWCVD) for solar cells and thin film transistors (TFTs). The deposition process of H

  2. 77 GHz MEMS antennas on high-resistivity silicon for linear and circular polarization

    KAUST Repository

    Sallam, M. O.

    2011-07-01

    Two new MEMS antennas operating at 77 GHz are presented in this paper. The first antenna is linearly polarized. It possesses a vertical silicon wall that carries a dipole on top of it. The wall is located on top of silicon substrate covered with a ground plane. The other side of the substrate carries a microstrip feeding network in the form of U-turn that causes 180 phase shift. This phase-shifter feeds the arms of the dipole antenna via two vertical Through-Silicon Vias (TSVs) that go through the entire wafer. The second antenna is circularly polarized and formed using two linearly polarized antennas spatially rotated with respect to each other by 90 and excited with 90 phase shift. Both antennas are fabricated using novel process flow on a single high-resistivity silicon wafer via bulk micromachining. Only three processing steps are required to fabricate these antennas. The proposed antennas have appealing characteristics, such as high polarization purity, high gain, and high radiation efficiency. © 2011 IEEE.

  3. Ultra-high efficiency, fast graphene micro-heater on silicon

    DEFF Research Database (Denmark)

    Yan, Siqi; Zhu, Xiaolong; Frandsen, Lars Hagedorn

    2017-01-01

    We demonstrate an ultra-high efficiency and fast graphene microheater on silicon photonic crystal waveguide. By taking advantage of slow-light effect, a tuning efficiency of 1.07 nm/mW and power consumption per free spectral range of 3.99 mW. A fast rise and decay times (10% to 90%) of only 750 ns...

  4. Carbon−Silicon Core−Shell Nanowires as High Capacity Electrode for Lithium Ion Batteries

    KAUST Repository

    Cui, Li-Feng

    2009-09-09

    We introduce a novel design of carbon-silicon core-shell nanowires for high power and long life lithium battery electrodes. Amorphous silicon was coated onto carbon nanofibers to form a core-shell structure and the resulted core-shell nanowires showed great performance as anode material. Since carbon has a much smaller capacity compared to silicon, the carbon core experiences less structural stress or damage during lithium cycling and can function as a mechanical support and an efficient electron conducting pathway. These nanowires have a high charge storage capacity of ∼2000 mAh/g and good cycling life. They also have a high Coulmbic efficiency of 90% for the first cycle and 98-99.6% for the following cycles. A full cell composed of LiCoO2 cathode and carbon-silicon core-shell nanowire anode is also demonstrated. Significantly, using these core-shell nanowires we have obtained high mass loading and an area capacity of ∼4 mAh/cm2, which is comparable to commercial battery values. © 2009 American Chemical Society.

  5. Language Teachers’ Burnout and Gender

    Directory of Open Access Journals (Sweden)

    Mahboobeh Jamshidirad

    2012-09-01

    Full Text Available The purpose of this study was to investigate the effect of gender on the three burnout dimensions; emotional exhaustion (EE, depersonalization (DP and personal accomplishment (PA among English language teachers in Malaysia. This study was a quantitative survey study. The Maslach Burnout Inventory-Educators Survey (MBI-ES (Maslach, Jackson, & Schwab, 1986 was used to collect the data to determine the burnout levels of the teachers with respect to its three dimensions. These Data was collected from 28 English language teachers (50% female. Descriptive and inferential statistics including frequency, percentage, means, standard deviations, and t-test were used in the analysis. The results showed that gender was not a predictor of burnout in this sample. The study can have useful implications for educational administrators who deal with language teachers. Keywords: burnout, emotional exhaustion, depersonalization, reduced personal accomplishment, gender, language teachers

  6. Study on high efficient electric discharge milling of silicon carbide ceramic with high resistivity

    Institute of Scientific and Technical Information of China (English)

    JI RenJie; LIU YongHong; YU LiLi; LI XiaoPeng; DONG Xin

    2008-01-01

    A new method which employs a group pulse power supply for electric discharge milling of the silicon high pulse utilization, the material removal rate (MRR) can reach 72.9 mm3/min. The effects of high-frequency pulse duration, high-frequency pulse interval, peak voltage, peak current, polarity, ro-tate speed and group frequency on the process performance have been investigated. Also the EDMed surface microstructure is examined with a scanning electron microscope (SEM), an X-ray diffraction (XRD), an energy dispersive spectrometer (EDS) and a micro hardness tester. The results show that the conditions of smaller high-frequency pulse duration and pulse interval, higher peak voltage and peak current, and positive tool polarity are suitable for machining the SiC ceramic. The optimal rotate speed is 1090 r/rain and the preferable group frequency is 730 Hz. In addition, there is a small quantity of iron on machined surface when machining with steel electrode. The average grain size of the EDMed sur-face is smaller than that of the unprocessed, and the micro hardness of machined surface is superior to that of the unprocessed.

  7. High temperature Hexoloy{trademark} SX silicon carbide. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, G.V.; Lau, S.K.; Storm, R.S. [Carborundum Co., Niagara Falls, NY (United States)

    1994-09-01

    HEXOLOY{reg_sign} SX-SiC, fabricated with Y and Al containing compounds as sintering aids, has been shown to possess significantly improved strength and toughness over HEXOLOY{reg_sign}SA-SiC. This study was undertaken to establish and benchmark the complete mechanical property database of a first generation material, followed by a process optimization task to further improve the properties. Mechanical characterization on the first generation material indicated that silicon-rich pools, presumably formed as a reaction product during sintering, controlled the strength from room temperature to 1,232 C. At 1,370 C in air, the material was failing due to a glass-phase formation at the surface. This glass-phase formation was attributed to the reaction of yttrium aluminates, which exist as a second phase in the material, with the ambient. This process was determined to be a time-dependent one that leads to slow crack growth. Fatigue experiments clearly indicated that the slow crack growth driven by the reaction occurred only at temperatures >1,300 C, above the melting point of the glass phase. Process optimization tasks conducted included the selection of the best SiC powder source, studies on mixing/milling conditions for SiC powder with the sintering aids, and a designed experiment involving a range of sintering and post-treatment conditions. The optimization study conducted on the densification variables indicated that lower sintering temperatures and higher post-treatment pressures reduce the Si-rich pool formation, thereby improving the room-temperature strength. In addition, it was also determined that furnacing configuration and atmosphere were critical in controlling the Si-rich formation.

  8. In-line high-rate evaporation of aluminum for the metallization of silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mader, Christoph Paul

    2012-07-11

    This work focuses on the in-line high-rate evaporation of aluminum for contacting rear sides of silicon solar cells. The substrate temperature during the deposition process, the wafer bow after deposition, and the electrical properties of evaporated contacts are investigated. Furthermore, this work demonstrates for the first time the formation of aluminum-doped silicon regions by the in-line high-rate evaporation of aluminum without any further temperature treatment. The temperature of silicon wafers during in-line high-rate evaporation of aluminum is investigated in this work. The temperatures are found to depend on the wafer thickness W, the aluminum layer thickness d, and on the wafer emissivity {epsilon}. Two-dimensional finite-element simulations reproduce the measured peak temperatures with an accuracy of 97%. This work also investigates the wafer bow after in-line high-rate evaporation and shows that the elastic theory overestimates the wafer bow of planar Si wafers. The lower bow is explained with plastic deformation in the Al layer. Due to the plastic deformation only the first 79 K in temperature decrease result in a bow formation. Furthermore the electrical properties of evaporated point contacts are examined in this work. Parameterizations for the measured saturation currents of contacted p-type Si wafers and of contacted boron-diffused p{sup +}-type layers are presented. The contact resistivity of the deposited Al layers to silicon for various deposition processes and silicon surface concentrations are presented and the activation energy of the contact formation is determined. The measured saturation current densities and contact resistivities of the evaporated contacts are used in one-dimensional numerical Simulations and the impact on energy conversion efficiency of replacing a screen-printed rear side by an evaporated rear side is presented. For the first time the formation of aluminum-doped p{sup +}-type (Al-p{sup +}) silicon regions by the in

  9. Longitudinal burnout-collaboration patterns in Japanese medical care workers at special needs schools: a latent class growth analysis

    Directory of Open Access Journals (Sweden)

    Kanayama M

    2016-06-01

    Full Text Available Mieko Kanayama,1 Machiko Suzuki,1 Yoshikazu Yuma2 1Department of Human Health Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan; 2Department of Human Development Education, Graduate School of Education, Hyogo University of Teacher Education, Kato, Hyogo, Japan Abstract: The present study aimed to identify and characterize potential burnout types and the relationship between burnout and collaboration over time. Latent class growth analysis and the growth mixture model were used to identify and characterize heterogeneous patterns of longitudinal stability and change in burnout, and the relationship between burnout and collaboration. We collected longitudinal data at three time points based on Japanese academic terms. The 396 study participants included academic teachers, yogo teachers, and registered nurses in Japanese special needs schools. The best model included four types of both burnout and collaboration in latent class growth analysis with intercept, slope, and quadratic terms. The four types of burnout were as follows: low stable, moderate unstable, high unstable, and high decreasing. They were identified as involving inverse collaboration function. The results indicated that there could be dynamic burnout types, namely moderate unstable, high unstable, and high decreasing, when focusing on growth trajectories in latent class analyses. The finding that collaboration was dynamic for dynamic burnout types and stable for stable burnout types is of great interest. This was probably related to the inverse relationship between the two constructs. Keywords: burnout, collaboration, latent class growth analysis, interprofessional care, special needs schools

  10. The Physics of Boiling at Burnout

    Science.gov (United States)

    Theofanous, T. G.; Tu, J. P.; Dinh, T. N.; Salmassi, T.; Dinh, A. T.; Gasljevic, K.

    2000-01-01

    The basic elements of a new experimental approach for the investigation of burnout in pool boiling are presented. The approach consists of the combined use of ultrathin (nano-scale) heaters and high speed infrared imaging of the heater temperature pattern as a whole, in conjunction with highly detailed control and characterization of heater morphology at the nano and micron scales. It is shown that the burnout phenomenon can be resolved in both space and time. Ultrathin heaters capable of dissipating power levels, at steady-state, of over 1 MW/square m are demonstrated. A separation of scales is identified and it is used to transfer the focus of attention from the complexity of the two-phase mixing layer in the vicinity of the heater to a micron-scaled microlayer and nucleation and associated film-disruption processes within it.

  11. Silicon electro-optic modulator with high-permittivity gate dielectric layer

    Institute of Scientific and Technical Information of China (English)

    Mengxia Zhu; Zhiping Zhou; Dingshan Gao

    2009-01-01

    A high-permittivity (high-k) material is applied as the gate dielectric layer in a silicon metal-oxidesemiconductor (MOS) capacitor to form a special electro-optic (EO) modulator.Both induced charge density and modulation efficiency in the proposed modulator are improved due to the special structure design and the application of the high-k material.The device has an ultra-compact dimension of 691 μm in length.

  12. Silicon Carbide-Based Hydrogen Gas Sensors for High-Temperature Applications

    OpenAIRE

    Sangchoel Kim; Jehoon Choi; Minsoo Jung; Seongjeen Kim; Sungjae Joo

    2013-01-01

    We investigated SiC-based hydrogen gas sensors with metal-insulator-semiconductor (MIS) structure for high temperature process monitoring and leak detection applications in fields such as the automotive, chemical and petroleum industries. In this work, a thin tantalum oxide (Ta2O5) layer was exploited with the purpose of sensitivity improvement, because tantalum oxide has good stability at high temperature with high permeability for hydrogen gas. Silicon carbide (SiC) was used as a substrate ...

  13. High Power Silicon Carbide (SiC) Power Processing Unit Development

    Science.gov (United States)

    Scheidegger, Robert J.; Santiago, Walter; Bozak, Karin E.; Pinero, Luis R.; Birchenough, Arthur G.

    2015-01-01

    NASA GRC successfully designed, built and tested a technology-push power processing unit for electric propulsion applications that utilizes high voltage silicon carbide (SiC) technology. The development specifically addresses the need for high power electronics to enable electric propulsion systems in the 100s of kilowatts. This unit demonstrated how high voltage combined with superior semiconductor components resulted in exceptional converter performance.

  14. Medium-energy heavy-ion single-event-burnout imaging of power MOSFETs

    Energy Technology Data Exchange (ETDEWEB)

    Musseau, O.; Torres, A.; Campbell, A.B.; Knudson, A.R.; Buchner, S.; Fischer, B.; Schloegl, M.; Briand, P.

    1999-12-01

    The authors present the first experimental determination of the SEB sensitive area in a power MOSFET irradiated with a high-LET heavy-ion microbeam. They used a spectroscopy technique to perform coincident measurements of the charge collected in both source and drain junctions together, with a non-destructive technique (current limitation). The resulting charge collection images are related to the physical structure of the individual cells. These experimental data reveal the complex 3-dimensional behavior of a real structure, which can not easily be simulated using available tools. As the drain voltage is increased, the onset of burnout is reached, characterized by a sudden change in the charge collection image. Hot spots are observed where the collected charge reaches its maximum value. Those spots, due to burnout triggering events, correspond to areas where the silicon is degraded through thermal effects along a single ion track. This direct observation of SEB sensitive areas as applications for, either device hardening, by modifying doping profiles or layout of the cells, or for code calibration and device simulation.

  15. High-efficiency and low-jitter Silicon single-photon avalanche diodes based on nanophotonic absorption enhancement

    CERN Document Server

    Ma, Jian; Yu, Zongfu; Jiang, Xiao; Huo, Yijie; Zang, Kai; Zhang, Jun; Harris, James S; Jin, Ge; Zhang, Qiang; Pan, Jian-Wei

    2015-01-01

    Silicon single-photon avalanche diode (SPAD) is a core device for single-photon detection in the visible and the near-infrared range, and widely used in many applications. However, due to limits of the structure design and device fabrication for current silicon SPADs, the key parameters of detection befficiency and timing jitter are often forced to compromise. Here, we propose a nanostructured silicon SPAD, which achieves high detection efficiency with excellent timing jitter simultaneously over a broad spectral range. The optical and electric simulations show significant performance enhancement compared with conventional silicon SPAD devices. This nanostructured devices can be easily fabricated and thus well suited for practical applications.

  16. Why do perfectionists have a higher burnout risk than others? The mediational effect of workaholism

    Directory of Open Access Journals (Sweden)

    van Beek, Ilona

    2010-04-01

    Full Text Available Previous research has revealed that perfectionists have a higher burnout risk than others, but the mechanisms accounting for this association have rarely been examined. The present study proposes that workaholism mediates this relation, as previous research revealed that (a perfectionists are more likely to be workaholics than others, and (b workaholics have a higher burnout risk than others. Using cross-sectional data from 199 Dutch managers, regression analyses revealed that holding high standards towards oneself (a self-directed indicator of perfectionism was unrelated to any of the three dimensions of the Maslach Burnout Inventory. However, high concern over making mistakes in the face of others (representing socially prescribed perfectionism was systematically associated with high levels of burnout and workaholism. Moreover, workaholism was positively associated with high levels of exhaustion. Subsequent mediation analysis revealed that the association between (the socially prescribed aspect of perfectionism and burnout (emotional exhaustion was mediated by workaholism.

  17. Industrially feasible, dopant-free, carrier-selective contacts for high-efficiency silicon solar cells

    KAUST Repository

    Yang, Xinbo

    2017-05-31

    Dopant-free, carrier-selective contacts (CSCs) on high efficiency silicon solar cells combine ease of deposition with potential optical benefits. Electron-selective titanium dioxide (TiO) contacts, one of the most promising dopant-free CSC technologies, have been successfully implemented into silicon solar cells with an efficiency over 21%. Here, we report further progress of TiO contacts for silicon solar cells and present an assessment of their industrial feasibility. With improved TiO contact quality and cell processing, a remarkable efficiency of 22.1% has been achieved using an n-type silicon solar cell featuring a full-area TiO contact. Next, we demonstrate the compatibility of TiO contacts with an industrial contact-firing process, its low performance sensitivity to the wafer resistivity, its applicability to ultrathin substrates as well as its long-term stability. Our findings underscore the great appeal of TiO contacts for industrial implementation with their combination of high efficiency with robust fabrication at low cost.

  18. Structure and selected properties of high-aluminium Zn alloy with silicon addition

    Directory of Open Access Journals (Sweden)

    A. Zyska

    2011-07-01

    Full Text Available The results of examinations concerning the abrasive wear resistance, hardness, and thermal expansion of high-aluminium zinc alloys are presented. The examinations were carried out for five synthetic ZnAl28 alloys with variable silicon content ranging from 0.5% to 3.5%, and – for the purpose of comparison – for the standardised ZnAl28Cu4 alloy. It was found that silicon efficiently increases the tribological properties and decreases the coefficient of thermal expansion of zinc alloys. The most advantageous set of the examined properties is exhibited by the alloys containing over 2.5% Si. They are characterised by higher parameters as compared with the standardised alloy. Observations of microstructures reveal that silicon precipitates as a separate compact phase, and its morphology depends on t he Si content in the alloy. The performed examinations show that silicon can satisfactorily replace copper in high aluminium Zn alloys, thus eliminating the problem of dimensional instability of castings.

  19. Silicone rubber-coated highly sensitive optical fiber sensor for temperature measurement

    Science.gov (United States)

    Bhardwaj, Vanita; Gangwar, Rahul Kumar; Singh, Vinod Kumar

    2016-12-01

    A silicone rubber-coated Mach-Zehnder interferometer (MZI) is proposed and applied to temperature measurement. The MZI is fabricated by splicing single mode fiber between a short section of no-core fiber (NCF) and the ultra-abrupt taper region. The sensing length of MZI is coated with liquid silicone rubber to enhance the temperature sensitivity. Here, NCF is used to excite the higher order cladding mode, the ultra-abrupt taper region acts as a optical fiber coupler, and the silicone rubber coating on sensing length is used as solid cladding material instead of liquid. The enhancement of the sensitivity of a device is due to the high refractive index (1.42) and thermo-optic coefficient (-1.4×10-4/°C) of silicone rubber as compared to liquid cladding temperature sensors. The experiment was performed for both coated and uncoated MZI and the results were compared. The MZI exhibits a high temperature sensitivity of 253.75 and 121.26 pm/°C for coated and uncoated sensing probes, respectively, in the temperature range from 30°C to 75°C.

  20. Job burnout and employee engagement : A meta-analytic examination of construct proliferation

    NARCIS (Netherlands)

    Cole, M.S.; Walter, F.; Bedeian, A.G.; O'Boyle, E.H.

    2012-01-01

    Drawing on 50 unique samples (from 37 studies), the authors used meta-analytical techniques to assess the extent to which job burnout and employee engagement are independent and useful constructs. The authors found that (a) dimension-level correlations between burnout and engagement are high, (b) bu

  1. Teacher- and School-Level Predictors of Teacher Efficacy and Burnout: Identifying Potential Areas for Support

    Science.gov (United States)

    Pas, Elise T.; Bradshaw, Catherine P.; Hershfeldt, Patricia A.

    2012-01-01

    Although several studies relate low teacher efficacy and high burnout to the quality of instruction and students' academic achievement, there has been limited research examining factors that predict teacher efficacy and burnout. The current study employed a longitudinal, multilevel modeling approach to examine the influence of teacher- and…

  2. An Examination of Academic Burnout versus Work Engagement among Taiwanese Adolescents

    Science.gov (United States)

    Shih, Shu-Shen

    2012-01-01

    The author attempted to examine how Taiwanese junior high school students' perfectionistic tendencies and achievement goals were related to their academic burnout versus work engagement, and to determine differences in the indicators of burnout versus engagement among students with different subtypes of perfectionism. A total of 456 eighth-grade…

  3. Correlation between burnout and professional value in Chinese oncology nurses: A questionnaire survey

    Directory of Open Access Journals (Sweden)

    Fang Cheng

    2015-06-01

    Clinical implication: The prevalence of job burnout in oncology nurses is high, and this could be improved by increasing perception of professional value. It is urgent for managers to strengthen professional value education and to take strategies that reduce job burnout, which is important for the overall quality and safety of nursing.

  4. The role of social support in burnout among Dutch medical residents

    NARCIS (Netherlands)

    Prins, Jelle T.; Hoekstra-Weebers, J.E.; Gazendam-Donofrio, S.M.; van de Wiel, H.B.; Sprangers, F.; Jaspers, F.C.; van der Heijden, F.M.

    2007-01-01

    Burnout levels among medical residents are considered high. A lack of social support has shown to have a direct effect on emotional exhaustion, and depersonalization, two of the three burnout indicators. In this study, we examined the satisfaction of medical residents with social support (emotional,

  5. Demand–Control Model and its Relationship with Burnout Syndrome in Nurses

    Directory of Open Access Journals (Sweden)

    Ahmad Heidari Pahlavian

    2015-05-01

    Conclusion: Based on the results of the study should be stated that if job control and psychological job demand were high, nurses will not be prone to burnout. And also occurrence of burnout in reduced personal accomplishment dimension among nurses who reported their job had low psychosocial demand and low control, was more than others.

  6. The problem of competitiveness and "burnout syndrome" of teachers in the conditions of continuous education

    OpenAIRE

    Pyarlaytine Elena Nikolaevna

    2015-01-01

    The teacher’s profession has a high level of emotional loading, which in combination with other factors can lead to a syndrome of emotional burnout. By using a set of measures in psychologist's work, we aim at the prevention of burnout, helping to preserve mental and physical health.

  7. Job burnout and employee engagement : A meta-analytic examination of construct proliferation

    NARCIS (Netherlands)

    Cole, M.S.; Walter, F.; Bedeian, A.G.; O'Boyle, E.H.

    Drawing on 50 unique samples (from 37 studies), the authors used meta-analytical techniques to assess the extent to which job burnout and employee engagement are independent and useful constructs. The authors found that (a) dimension-level correlations between burnout and engagement are high, (b)

  8. The Relationship between Teacher Stress and Burnout in Hong Kong: Positive Humour and Gender as Moderators

    Science.gov (United States)

    Ho, Sammy K.

    2017-01-01

    In this study, we report on the relationship between positive humour and burnout among 379 secondary school teachers in Hong Kong, and explore whether the relationship varies according to gender. The moderating effects of both affiliative and self-enhancing humour on each burnout component were then examined. High affiliative and self-enhancing…

  9. Burnout, working conditions and gender - results from the northern Sweden MONICA Study

    Directory of Open Access Journals (Sweden)

    Lindahl Bernt

    2010-06-01

    Full Text Available Abstract Background Sick-leave because of mental and behavioural disorders has increased considerably in Sweden since the late nineties, and especially in women. The aim of this study was to assess the level of burnout in the general working population in northern Sweden and analyse it's relation to working conditions and gender. Methods In this cross-sectional study the survey from the MONICA-study (Monitoring of Trends and Determinants in Cardiovascular Disease in northern Sweden 2004 was used. A burnout instrument, the Shirom Melamed Burnout Questionnaire (SMBQ, was incorporated in the original survey which was sent to a random sample of 2500 individuals with a response rate of 76%. After including only actively working people, aged 25-64 years, our study population consisted of 1000 participants (497 women and 503 men. ANOVA and multiple linear regression models were used. Results The prevalence of a high level of burnout (SMBQ >4.0 was 13%. Women had a higher level of burnout than men with the most pronounced difference in the age group 35-44 years. In both sexes the level of burnout decreased with age. Demand and control at work, and job insecurity were related to burnout. In women the level of education, socioeconomic position, work object, and working varying hours were of importance. Interaction effects were found between sex and work object, and sex and working hours. In a multiple regression analysis almost half of the gender difference could be explained by work related and life situational factors. Conclusions Working life conditions contributed to the level of burnout in this actively working sample from the general population in northern Sweden. Especially in women, socioeconomic position was associated with burnout. The high level of burnout in women compared to men was partly explained by more unfavourable working conditions and life situational factors. Efforts to level out gender differences in burnout should probably focus on

  10. Performance optimization of high-order Lamb wave sensors based on silicon carbide substrates.

    Science.gov (United States)

    Chen, Zhe; Fan, Li; Zhang, Shu-yi; Zhang, Hui

    2016-02-01

    Silicon carbide (SiC), as a new type of material for substrates in micro-electromechanical system (MEMS), was given high consideration in virtue of the properties of high acoustic velocity, low loss, chemical resistance, and etc. In this work, five performance parameters, which are electromechanical coupling coefficients, mass sensitivities, conductivity sensitivities, insert losses and minimum detectable masses, are theoretically investigated in Lamb wave chemical sensors for gas sensing based on SiC substrates. It is presented that higher performance can be achieved based on high-order modes other than fundamental modes, and the abovementioned five parameters can be simultaneously optimized. Then, according to the optimized operating conditions, operating parameters of the SiC-based high-order Lamb wave sensors are designed, which can be easily realized in MEMS technology. Finally, it is demonstrates that the SiC-based sensor exhibits better performance than that of the sensor with a conventional silicon substrate.

  11. Effect of extrusion temperature on the physical properties of high-silicon aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    YANG Fuliang; GAN Weiping; CHEN Zhaoke

    2007-01-01

    Light-weight high-silicon aluminum alloys are used for electronic packaging in the aviation and space- flight industry. Al-30Si and Al-40Si are fabricated with air- atomization and vacuum-canning hot-extrusion process. The density, thermal conductivity, hermeticity and thermal expan- sion coefficients of the material are measured, and the relationship between extrusion temperature and properties is obtained. Experimental results show that the density of high- silicon aluminum alloys prepared with this method is as high as 99.64% of the theory density, and increases with elevating extrusion temperature. At the same time, thermal conductiv- ity varies between 104-140W/(m.K); with the extrusion temperature, thermal expansion coefficient also increases but within 13 × 10-6 (at 100℃) and hermeticity of the material is high to 10-9 order of magnitude.

  12. Dielectric elastomers, with very high dielectric permittivity, based on silicone and ionic interpenetrating networks

    DEFF Research Database (Denmark)

    Yu, Liyun; Madsen, Frederikke Bahrt; Hvilsted, Søren;

    2015-01-01

    Dielectric elastomers (DEs), which represent an emerging actuator and generator technology, admittedly have many favourable properties, but their high driving voltages are one of the main obstacles to commercialisation. One way to reduce driving voltage is by increasing the ratio between dielectr...... as well as relatively high breakdown strength. All IPNs have higher dielectric losses than pure silicone elastomers, but when accounting for this factor, IPNs still exhibit satisfactory performance improvements....... is demonstrated herein, and a number of many and important parameters, such as dielectric permittivity/loss, viscoelastic properties and dielectric breakdown strength, are investigated. Ionic and silicone elastomer IPNs are promising prospects for dielectric elastomer actuators, since very high permittivities......Dielectric elastomers (DEs), which represent an emerging actuator and generator technology, admittedly have many favourable properties, but their high driving voltages are one of the main obstacles to commercialisation. One way to reduce driving voltage is by increasing the ratio between dielectric...

  13. Burnout Syndrome During Residency.

    Science.gov (United States)

    Turgut, Namigar; Karacalar, Serap; Polat, Cengiz; Kıran, Özlem; Gültop, Fethi; Kalyon, Seray Türkmen; Sinoğlu, Betül; Zincirci, Mehmet; Kaya, Ender

    2016-10-01

    The aim of this study is identified the degree of Burnout Syndrome (BOS) and find out its correlation with years of recidency and sociodemograpfic chareacteristics, training, sleeping habits, such as smoking and alcohol consumption. After approval from the Hospital Ethics Committee and obtaining informed consent, First, second, third, fourth and fifth year of recidency staff (n=127) working in our hospital were involved in this study. The standardized Maslach Burnout Inventory (MBI) was used in this study. Fifty six male (44.1%) and seventy one female (55.9%) residents were enroled in this study (Coranbach Alfa(α)=0.873). 57% of the first year residents smokes cigaret and 54% of them use alcohol. 2% of them gets one day off after hospital night shift, 61% of them suffers from disturbed sleep. 60% of them had been stated that they willingly selected their profession. 61% of them prefers talking to friends and 32% of them prefers shopping to overcome stress. There were statistical difference acording to years of recidency in MBI, Emotional Burnout (EB) and desensitisation scale (DS) points. EB scale points of the second year of residency group was statisticaly higher than fourth year of residency group. DS points of second year of residency group was also statisticaly higher than the third and fourth year of residency group. There was no statistical difference between any groups in Personal Success. BOS is a frequent problem during residency in anaesthesia. Appropriate definition and awareness are the first important steps to prevent this syndrome. Further administrative approaches should be evaluated with regard to their effects.

  14. Silicon carbide thin films for high temperature microelectromechanical systems

    Science.gov (United States)

    Fleischman, Aaron Judah

    Silicon Carbide (SiC) was studied for use as a material in microelectromechanical systems (MEMS). An APCVD reactor was built to deposit SiC on 100-mm diameter substrates. 3C-SiC films were grown heteroepitaxially atop 100-mm Si wafers. SiC was deposited atop suitable sacrificial layers of polysilicon and thermal oxide. The reactor gas flow was modeled using finite element techniques. The gas flow formed a recirculating pattern, with fresh reactant gases injected at the top of the reactor, traveling down the inside sidewalls and introduced at the bottom of the wafer, forming a plume of heated gases rising to the top of the reactor. This recirculation pattern explains the gradually decreasing growth rate from the wafer's bottom to its top as reactant gases are gradually depleted as they rise. Intentional doping of 3C-SiC films was studied, using diborane and phosphine dopant sources. SIMS indicated that B and P could be incorporated into 3C-SiC films, however B doped films were electrically compensated due to trace amounts of nitrogen in the diborane. Boron concentrations above 3C-SiC's solid solubility caused the SiC to become polycrystalline. Phosphorus incorporation was less predictable and did not vary linearly with phosphine flow rates. A reactive ion etch (REE) process was developed to etch 3C-SiC. Addition of He to the plasma chemistry enhanced the etch rates and etch anisotropy of the 3C-SiC. The etch recipe also produced similar results for polycrystalline SiC on polysilicon and thermal oxide. A maximum SiC etch rate of 1,267 A/min with a selectivity of 1.4 to Si was obtained. Using the above methods, SiC resonant devices were fabricated using polysilicon and thermal oxide as sacrificial layers. Polysilicon resonant devices were fabricated for comparison. The devices were tested by measuring their resonant frequency at room and elevated temperatures to 900°C to determine Young's modulus and its temperature dependence. All devices showed resonant frequency

  15. A sub-atmospheric chemical vapor deposition process for deposition of oxide liner in high aspect ratio through silicon vias.

    Science.gov (United States)

    Lisker, Marco; Marschmeyer, Steffen; Kaynak, Mehmet; Tekin, Ibrahim

    2011-09-01

    The formation of a Through Silicon Via (TSV) includes a deep Si trench etching and the formation of an insulating layer along the high-aspect-ratio trench and the filling of a conductive material into the via hole. The isolation of the filling conductor from the silicon substrate becomes more important for higher frequencies due to the high coupling of the signal to the silicon. The importance of the oxide thickness on the via wall isolation can be verified using electromagnetic field simulators. To satisfy the needs on the Silicon dioxide deposition, a sub-atmospheric chemical vapor deposition (SA-CVD) process has been developed to deposit an isolation oxide to the walls of deep silicon trenches. The technique provides excellent step coverage of the 100 microm depth silicon trenches with the high aspect ratio of 20 and more. The developed technique allows covering the deep silicon trenches by oxide and makes the high isolation of TSVs from silicon substrate feasible which is the key factor for the performance of TSVs for mm-wave 3D packaging.

  16. Silicon Light: a European FP7 project aiming at high efficiency thin film silicon solar cells on foil. Monolithic series interconnection of flexible thin-film PV devices

    Energy Technology Data Exchange (ETDEWEB)

    Soppe, W. [ECN Solar Energy, P.O. Box 1, 1755 ZG Petten (Netherlands); Haug, F.J. [Ecole Polytechnique Federale de Lausanne EPFL, Photovoltaics and Thin Film Electronics Laboratory, Rue A.-L. Breguet 2, 2000 Neuchatel (Switzerland); Couty, P. [VHFTechnologies SA, Rue Edouard-Verdan 2, CH-1400 Yverdon-les-Bains (Switzerland); Duchamp, M. [Technical University of Denmark, Center for Electron Nanoscopy, DK-2800 Kongens Lyngby (Denmark); Schipper, W. [Nanoptics GmbH, Innungstr.5, 21244 Buchholz (Germany); Krc, J. [University of Ljubljana, Faculty of Electrical Engineering, Trzaska 25, SI-1000 Ljubljana (Slovenia); Sanchez, G. [Universidad Politecnica de Valencia, I.U.I. Centro de Tecnologia Nanofotonica, 46022 Valencia (Spain); Leitner, K. [Umicore Thin Film Products AG, Balzers (Liechtenstein); Wang, Q. [Shanghai Jiaotong University, Research Institute of Micro/Nanometer Science and Technology, 800 Dongchuan Road, Min Hang, 200240 Shanghai (China)

    2011-09-15

    Silicon-Light is a European FP7 project, which started January 1st, 2010 and aims at development of low cost, high-efficiency thin film silicon solar cells on foil. Three main routes are explored to achieve these goals: (a) advanced light trapping by implementing nanotexturization through UV Nano Imprinting Lithography (UV-NIL); (b) growth of crack-free silicon absorber layers on highly textured substrates; (c) development of new TCOs which should combine the best properties of presently available materials like ITO and AZO. The paper presents the midterm status of the project results, showing model calculations of ideal nanotextures for light trapping in thin film silicon solar cells; the fabrication of masters and the replication and roll-to-roll fabrication of these nanotextures. Further, results on ITO variants with improved work function are presented. Finally, the status of cell fabrication on foils with nanotexture is shown. Microcrystalline and amorphous silicon single junction cells with stable efficiencies with more than 8% have been made, paving the way towards a-Si/{mu}c-Si tandem cells with more than 11% efficiency.

  17. High-resolution patterning of graphene by screen printing with a silicon stencil for highly flexible printed electronics.

    Science.gov (United States)

    Hyun, Woo Jin; Secor, Ethan B; Hersam, Mark C; Frisbie, C Daniel; Francis, Lorraine F

    2015-01-07

    High-resolution screen printing of pristine graphene is introduced for the rapid fabrication of conductive lines on flexible substrates. Well-defined silicon stencils and viscosity-controlled inks facilitate the preparation of high-quality graphene patterns as narrow as 40 μm. This strategy provides an efficient method to produce highly flexible graphene electrodes for printed electronics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. 优质护理模式下传染科护士职业倦怠调查%Survey and analysis of job burnout of nurses in infectious disease units in the implementation of high quality nursing service

    Institute of Scientific and Technical Information of China (English)

    陈世容

    2015-01-01

    Objective:To investigate the situation of job burnout of nurses in infectious disease units in the implementation of high quali-ty nursing service in order to provide reference for taking the targeted intervention. Methods:MBI scale in Chinese version was used to in-vestigate the job burnout of 128 clinical nurses working in the infectious disease units in the implementation of the activities of high quality nursing service. Results:The scores of the three dimensions of emotional exhaustion(EE),depersonalization(DP)and personal accom-plishment(PA)of the nurses were respectively 10. 21 ± 2. 268,9. 67 ± 1. 981 and 10. 26 ± 2. 473 points;the detection rate of moderate and high job burnout was respectively 66. 41% and 14. 06%(EE),59. 38% and 10. 15%(DP),58. 60% and 14. 84%(PA);the se-verity of EE,DP,PA were significantly more than the norm in the Hangzhou area(P < 0. 01). There was statistically significant difference in the comparison of job burnout between the nurses with different professional title,length of service,ages and in the different units. Con-clusion:The job burnout is more serious in the high quality nursing model than that in the traditional nursing model. The severity of job burnout changes with the change of professional title,length of service,ages,workload and risks of the units.%目的:了解优质护理模式下传染科护士职业倦怠情况,为针对性干预提供参考。方法:采取 MBI 量表中文版(NBS)对我院128名临床一线传染科护士在优质护理服务活动中职业倦怠情况进行调查。结果:优质护理模式下,护士情感衰竭(EE)、去人格化(DP)和个人成就感丧失(PA)3个维度得分分别为(10.21±2.268)分、(9.67±1.981)分、(10.26±2.473)分;中度倦怠与高度倦怠检出率分别为 EE 66.41%、14.06%,DP 59.38%、10.15%,PA 58.60%、14.84%;EE、DP、PA 严重程度均显著高于杭州地区常模(P <0.01)。调查显示不同传染病

  19. Mindfulness, burnout, and effects on performance evaluations in internal medicine residents

    Directory of Open Access Journals (Sweden)

    Braun SE

    2017-08-01

    Full Text Available Sarah E Braun,1 Stephen M Auerbach,1 Bruce Rybarczyk,1 Bennett Lee,2 Stephanie Call2 1Department of Psychology, School of Humanities and Sciences, Virginia Commonwealth University, Richmond, VA, USA; 2Department of Internal Medicine, Division of General Medicine, Virginia Commonwealth University, Richmond, VA, USA Purpose: Burnout has been documented at high levels in medical residents with negative effects on performance. Some dispositional qualities, like mindfulness, may protect against burnout. The purpose of the present study was to assess burnout prevalence among internal medicine residents at a single institution, examine the relationship between mindfulness and burnout, and provide preliminary findings on the relation between burnout and performance evaluations in internal medicine residents.Methods: Residents (n = 38 completed validated measures of burnout at three time points separated by 2 months and a validated measure of dispositional mindfulness at baseline. Program director end-of-year performance evaluations were also obtained on 22 milestones used to evaluate internal medicine resident performance; notably, these milestones have not yet been validated for research purposes; therefore, the investigation here is exploratory.Results: Overall, 71.1% (n = 27 of the residents met criteria for burnout during the study. Lower scores on the “acting with awareness” facet of dispositional mindfulness significantly predicted meeting burnout criteria χ2(5 = 11.88, p = 0.04. Lastly, meeting burnout criteria significantly predicted performance on three of the performance milestones, with positive effects on milestones from the “system-based practices” and “professionalism” domains and negative effects on a milestone from the “patient care” domain.Conclusion: Burnout rates were high in this sample of internal medicine residents and rates were consistent with other reports of burnout during medical residency. Dispositional

  20. Students' Satisfaction with Life and Its Relation to School Burnout

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    Vali Mehdinezhad

    2015-12-01

    Full Text Available The purpose of this study was to investigate the relationship between school burnout and satisfaction with life for students in grade of 7th to 9th. A quantitative method used in this study. 351 subjects were selected using stratified sampling. The two questionnaires employed here were The Satisfaction with Life Scale with five items of the Diener et al. (1985 and School-Burnout Inventory with nine items and three component - exhaustion at schoolwork (EXH, cynicism toward the meaning of school (CYN, and sense of inadequacy at School (INAD - measures of school burnout of the Salmela-Aro et al. (2009. The findings of this study showed that the high school students described their satisfaction with life in relatively satisfactory and they have described their level of school burnout lower than average. The results also showed their school burnout in component of exhaustion at schoolwork was above average and in Components of cynicism toward the meaning of school, and sense of inadequacy at School were lower than average. The results showed that in overall there was no significant correlation between satisfaction with life and school burnout. However, there was relatively low positive correlation between students' satisfaction with life and exhaustion at schoolwork, relatively low negative correlation between students' satisfaction with life and cynicism toward the meaning of school, and no any significance correlation between students' satisfaction with life and sense of inadequacy at school. The results of stepwise regression showed that sub-dimensions of high school burnout scale together explained a total of 14.5 % of the variance in the satisfaction with life for the students in this study.