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Sample records for high burnout silicon

  1. First observations of power MOSFET burnout with high energy neutrons

    International Nuclear Information System (INIS)

    Oberg, D.L.; Wert, J.L.; Normand, E.; Majewski, P.P.; Wender, S.A.

    1996-01-01

    Single event burnout was seen in power MOSFETs exposed to high energy neutrons. Devices with rated voltage ≥400 volts exhibited burnout at substantially less than the rated voltage. Tests with high energy protons gave similar results. Burnout was also seen in limited tests with lower energy protons and neutrons. Correlations with heavy-ion data are discussed. Accelerator proton data gave favorable comparisons with burnout rates measured on the APEX spacecraft. Implications for burnout at lower altitudes are also discussed

  2. 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.

  3. Burnout

    OpenAIRE

    Woitsch, Marek

    2015-01-01

    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...

  4. 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

  5. High-End Silicon PDICs

    Directory of Open Access Journals (Sweden)

    H. Zimmermann

    2008-05-01

    Full Text Available An overview on integrated silicon photodiodes and photodiode integrated circuits (PDICs or optoelectronic integrated circuits (OEICs for optical storage systems (OSS and fiber receivers is given. It is demonstrated, that by using low-cost silicon technologies high-performance OEICs being true competitors for some III/V-semiconductor OEICs can be realized. OSS-OEICs with bandwidths of up to 380 MHz and fiber receivers with maximum data rates of up to 11 Gbps are described. Low-cost data comm receivers for plastic optical fibers (POF as well as new circuit concepts for OEICs and highly parallel optical receivers are described also in the following.

  6. Psychological and biographical differences between secondary school teachers experiencing high and low levels of burnout.

    Science.gov (United States)

    Pierce, C M; Molloy, G N

    1990-02-01

    A total of 750 teachers from 16 government and non-government schools from areas of contrasted socio-economic status (SES) responded to a questionnaire designed to investigate associations between selected aspects of burnout among teachers working in secondary schools in Victoria, Australia. By comparing high and low burnout groups on biographic, psychological and work pattern variables, differences between teachers experiencing high and low levels of burnout were identified. Multiple regression analyses assessed the relative importance of these variables in accounting for the variance in each of the three burnout subscales. School type was related to perceptions of stress and burnout. Higher levels of burnout were associated with poorer physical health, higher rates of absenteeism, lower self-confidence and more frequent use of regressive coping strategies. Teachers classified as experiencing high levels of burnout attributed most of the stress in their lives to teaching and reported low levels of career commitment and satisfaction. Further, teachers who recorded high levels of burnout were characterised by lower levels of the personality disposition of hardiness, lower levels of social support, higher levels of role stress and more custodial pupil control ideologies than their low-burnout counterparts. Psychological variables were found to be more significant predictors of burnout than biographical variables.

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

    Science.gov (United States)

    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…

  8. A Study of Turkish High School Students' Burnout and Proficiency Levels in Relation to Their Sex

    Science.gov (United States)

    Yeni Palabiyik, Pinar

    2014-01-01

    The present study examines high school students' burnout levels. The main aims of the study are to investigate whether their burnout levels vary according to gender and grade levels, and to check the correlation between overall burnout levels and their English language proficiency attained with a specific test. The study followed a quantitative…

  9. Interventions to prevent burnout in high risk individuals: evidence review

    OpenAIRE

    Bagnall, A-M; Jones, R; Akter, H; Woodall, J

    2016-01-01

    Although there is existing evidence on what works to treat burnout and work-related stress, there is less on what works to prevent it from occurring in the first place.\\ud \\ud This report provides an overview of literature covering how to prevent burnout and work-related stress in individuals and within organisations.

  10. Association between low empathy and high burnout among primary care physicians and nurses in Lleida, Spain.

    Science.gov (United States)

    Yuguero, Oriol; Ramon Marsal, Josep; Esquerda, Montserrat; Vivanco, Luis; Soler-González, Jorge

    2017-12-01

    Burnout is a growing problem among healthcare professionals and may be mitigated and even prevented by measures designed to promote empathy and resilience. We studied the association between burnout and empathy in primary care practitioners in Lleida, Spain and investigated possible differences according to age, sex, profession, and place of practice (urban versus rural). All general practitioners (GPs) and family nurses in the health district of Lleida (population 366 000) were asked by email to anonymously complete the Maslach Burnout Inventory (MBI) and the Jefferson Scale of Physician Empathy (JSPE) between May and July 2014. Tool consistency was evaluated by Cronbach's α, the association between empathy and burnout by Spearman's correlation coefficient, and the association between burnout and empathy and sociodemographic variables by the χ 2 test. One hundred and thirty-six GPs and 131 nurses (52.7% response rate) from six urban and 16 rural practices participated (78.3% women); 33.3% of respondents had low empathy, while 3.7% had high burnout. The MBI and JSPE were correlated (P empathy (P empathy. Although burnout was relatively uncommon in our sample, it was associated with low levels of empathy. This finding and our observation of lower empathy levels in rural settings require further investigation. [Box: see text].

  11. High rate of burnout among anaesthesiologists in Belgrade teaching hospitals: Results of a cross-sectional survey.

    Science.gov (United States)

    Milenović, Miodrag; Matejić, Bojana; Vasić, Vladimir; Frost, Elizabeth; Petrović, Nataša; Simić, Dušica

    2016-03-01

    Decisions by anaesthesiologists directly impact the treatment, safety, recovery and quality of life of patients. Physical or mental collapse due to overwork or stress (burnout) in anaesthesiologists may, therefore, be expected to negatively affect patients, departments, healthcare facilities and families. To evaluate the prevalence of burnout among anaesthesiologists in Belgrade public teaching hospitals. A cross-sectional survey. Anaesthesiologists in 10 Belgrade teaching hospitals. Burnout was assessed using Maslach Burnout Inventory-Human Services Survey. The response rate was 76.2% (205/272) with the majority of respondents women (70.7%). The prevalence of total burnout among anaesthesiologists in Belgrade teaching hospitals was 6.34%. Measured level of burnout as assessed by high emotional exhaustion, high depersonalisation and low personal accomplishment was 52.7, 12.2 and 28.8%, respectively. More than a quarter of the studied population responded in each category with symptoms of moderate burnout. We detected that sex, additional academic education, marital status and working conditions were risk factors for emotional exhaustion and depersonalisation. Ageing increased the likelihood of burnout by 21.3% with each additional year. Shorter professional experience and increased educational accomplishment increased the risk of total burnout by 272%. Burnout rates in Belgrade teaching hospitals among anaesthesiologists are higher than in foreign hospitals. Emotional and/or physical breakdowns can have serious effects when these individuals care for patients in extremely stressed situations that may occur perioperatively. Causes for burnout should be examined more closely and means implemented to reverse this process.

  12. Burnout in boiling heat transfer. Part III. High-quality forced-convection systems

    International Nuclear Information System (INIS)

    Bergles, A.E.

    1979-01-01

    This is the final part of a review of burnout during boiling heat transfer. The status of burnout in high-quality forced-convection systems is reviewed, and recent developments are summarized in detail. A general guide to the considerable literature is given. Parametric effects and correlations for water in circular and noncircular ducts are presented. Other topics discussed include transients, steam-generator applications, correlations for other fluids, fouling, and augmentation

  13. Chinese Anesthesiologists Have High Burnout and Low Job Satisfaction: A Cross-Sectional Survey.

    Science.gov (United States)

    Li, Hange; Zuo, Mingzhang; Gelb, Adrian W; Zhang, Biao; Zhao, Xiaohui; Yao, Dongdong; Xia, Di; Huang, Yuguang

    2018-03-01

    The Chinese health care system must meet the needs of 19% of the world's population. Despite recent economic growth, health care resources are unevenly distributed. This creates the potential for job stress and burnout. We therefore conducted a survey among anesthesiologists in the Beijing-Tianjin-Hebei region focusing on job satisfaction and burnout to determine the incidence and associated factors. A large cross-sectional study was performed in the Beijing-Tianjin-Hebei region of China. The anonymous questionnaire was designed to collect and analyze the following information: (1) demographic characteristics and employer information; (2) job satisfaction assessed by Minnesota Satisfaction Questionnaire; (3) burnout assessed by Maslach Burnout Inventory-Human Service Survey; and (4) sleep pattern and physician-patient communication. Surveys were completed and returned from 211 hospitals (response rate 74%) and 2873 anesthesiologists (response rate 70%) during the period of June to August 2015. The overall job satisfaction score of Minnesota Satisfaction Questionnaire was 65.3 ± 11.5. Among the participants, 69% (95% confidence interval [CI], 67%-71%) met the criteria for burnout. The prevalence of high emotional exhaustion, high depersonalization, and low personal accomplishment was 57% (95% CI, 55%-59%), 49% (95% CI, 47%-51%), and 57% (95% CI, 55%-58%), respectively. Using multivariable logistic regression analysis, we found that age, hospital category, working hours per week, caseload per day, frequency of perceived challenging cases, income, and sleep quality were independent variables associated with burnout. Anesthesiologists with a high level of depersonalization tended to engage in shorter preoperative conversations with patients, provide less information about pain or the procedure, and to have less empathy with them. The anesthesiologists in the Beijing-Tianjin-Hebei region of China expressed a below-average level of job satisfaction, and suffered a

  14. High yield silicon carbide prepolymers

    International Nuclear Information System (INIS)

    Baney, R.H.

    1982-01-01

    Prepolymers which exhibit good handling properties, and are useful for preparing ceramics, silicon carbide ceramic materials and articles containing silicon carbide, are polysilanes consisting of 0 to 60 mole% (CH 3 ) 2 Si units and 40 to 100 mole% CH 3 Si units, all Si valences being satisfied by CH 3 groups, other Si atoms, or by H atoms, the latter amounting to 0.3 to 2.1 weight% of the polysilane. They are prepared by reducing the corresponding chloro- or bromo-polysilanes with at least the stoichiometric amount of a reducing agent, e.g. LiAlH 4 . (author)

  15. Fear of failure, psychological stress, and burnout among adolescent athletes competing in high level sport.

    Science.gov (United States)

    Gustafsson, H; Sagar, S S; Stenling, A

    2017-12-01

    The purpose of this study was to investigate fear of failure in highly competitive junior athletes and the association with psychological stress and burnout. In total 258 athletes (152 males and 108 females) ranged in age from 15 to 19 years (M = 17.4 years, SD = 1.08) participated. Athletes competed in variety of sports including both team and individual sports. Results showed in a variable-oriented approach using regression analyses that one dimension, fear of experiencing shame and embarrassment had a statistically significant effect on perceived psychological stress and one dimension of burnout, reduced sense of accomplishment. However, adopting a person-oriented approach using latent class analysis, we found that athletes with high levels of fear failure on all dimensions scored high on burnout. We also found another class with high scores on burnout. These athletes had high scores on the individual-oriented dimensions of fear of failure and low scores on the other oriented fear of failure dimensions. The findings indicate that fear of failure is related to burnout and psychological stress in athletes and that this association is mainly associated with the individual-oriented dimensions of fear of failure. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Effects of job-related stress and burnout on asthenopia among high-tech workers.

    Science.gov (United States)

    Ostrovsky, Anat; Ribak, Joseph; Pereg, Avihu; Gaton, Dan

    2012-01-01

    Eye- and vision-related symptoms are the most frequent health problems among computer users. The findings of eye strain, tired eyes, eye irritation, burning sensation, redness, blurred vision and double vision, when appearing together, have recently been termed 'computer vision syndrome', or asthenopia. To examine the frequency and intensity of asthenopia among individuals employed in research and development departments of high-tech firms and the effects of job stress and burnout on ocular complaints, this study included 106 subjects, 42 high-tech workers (study group) and 64 bank employees (control group). All participants completed self-report questionnaires covering demographics, asthenopia, satisfaction with work environmental conditions, job-related stress and burnout. There was a significant between-group difference in the intensity of asthenopia, but not in its frequency. Burnout appeared to be a significant contributing factor to the intensity and frequency of asthenopia. This study shows that burnout is a significant factor in asthenopic complaints in high-tech workers. This manuscript analyses the effects of psychological environmental factors, such as job stress and burnout, on ocular complaints at the workplace of computer users. The findings may have an ergonomic impact on how to improve health, safety and comfort of the working environment among computer users, for better perception of the job environment, efficacy and production.

  17. Vertical integration of high-Q silicon nitride microresonators into silicon-on-insulator platform.

    Science.gov (United States)

    Li, Qing; Eftekhar, Ali A; Sodagar, Majid; Xia, Zhixuan; Atabaki, Amir H; Adibi, Ali

    2013-07-29

    We demonstrate a vertical integration of high-Q silicon nitride microresonators into the silicon-on-insulator platform for applications at the telecommunication wavelengths. Low-loss silicon nitride films with a thickness of 400 nm are successfully grown, enabling compact silicon nitride microresonators with ultra-high intrinsic Qs (~ 6 × 10(6) for 60 μm radius and ~ 2 × 10(7) for 240 μm radius). The coupling between the silicon nitride microresonator and the underneath silicon waveguide is based on evanescent coupling with silicon dioxide as buffer. Selective coupling to a desired radial mode of the silicon nitride microresonator is also achievable using a pulley coupling scheme. In this work, a 60-μm-radius silicon nitride microresonator has been successfully integrated into the silicon-on-insulator platform, showing a single-mode operation with an intrinsic Q of 2 × 10(6).

  18. High-density oxidized porous silicon

    International Nuclear Information System (INIS)

    Gharbi, Ahmed; Souifi, Abdelkader; Remaki, Boudjemaa; Halimaoui, Aomar; Bensahel, Daniel

    2012-01-01

    We have studied oxidized porous silicon (OPS) properties using Fourier transform infraRed (FTIR) spectroscopy and capacitance–voltage C–V measurements. We report the first experimental determination of the optimum porosity allowing the elaboration of high-density OPS insulators. This is an important contribution to the research of thick integrated electrical insulators on porous silicon based on an optimized process ensuring dielectric quality (complete oxidation) and mechanical and chemical reliability (no residual pores or silicon crystallites). Through the measurement of the refractive indexes of the porous silicon (PS) layer before and after oxidation, one can determine the structural composition of the OPS material in silicon, air and silica. We have experimentally demonstrated that a porosity approaching 56% of the as-prepared PS layer is required to ensure a complete oxidation of PS without residual silicon crystallites and with minimum porosity. The effective dielectric constant values of OPS materials determined from capacitance–voltage C–V measurements are discussed and compared to FTIR results predictions. (paper)

  19. Job satisfaction and cortisol awakening response in teachers scoring high and low on burnout.

    Science.gov (United States)

    Moya-Albiol, Luis; Serrano, Miguel Angel; Salvador, Alicia

    2010-11-01

    The burnout syndrome is an important psychosocial risk in the job context, especially in professions with a strong social interaction, as in the case of teaching. High levels of burnout have been related to negative psychological indicators and hormonal alterations. This study compares job satisfaction and the cortisol awakening response (CAR) in teachers scoring high (HB) and low (LB) on burnout. HB teachers showed lower job satisfaction and no significant differences in the CAR when compared with the LB group. The results of the study suggest a general dissatisfaction with work along with a different functioning of the hypothalamo-pituitary-adrenocortical axis in HB teachers. Although non significantly, they showed a lower magnitude of the CAR than LB teachers. When considering the whole sample, emotional exhaustion and depersonalization correlated negatively and personal accomplishment positively with each subscale of the job satisfaction questionnaire whereas cortisol levels or CAR did not correlate significantly with both burnout subscales and job satisfaction. These results should be taken into account when working to prevent burnout in teachers, as the modified parameters could be considered indicators of the onset or development of the syndrome.

  20. High damage tolerance of electrochemically lithiated silicon

    Science.gov (United States)

    Wang, Xueju; Fan, Feifei; Wang, Jiangwei; Wang, Haoran; Tao, Siyu; Yang, Avery; Liu, Yang; Beng Chew, Huck; Mao, Scott X.; Zhu, Ting; Xia, Shuman

    2015-01-01

    Mechanical degradation and resultant capacity fade in high-capacity electrode materials critically hinder their use in high-performance rechargeable batteries. Despite tremendous efforts devoted to the study of the electro–chemo–mechanical behaviours of high-capacity electrode materials, their fracture properties and mechanisms remain largely unknown. Here we report a nanomechanical study on the damage tolerance of electrochemically lithiated silicon. Our in situ transmission electron microscopy experiments reveal a striking contrast of brittle fracture in pristine silicon versus ductile tensile deformation in fully lithiated silicon. Quantitative fracture toughness measurements by nanoindentation show a rapid brittle-to-ductile transition of fracture as the lithium-to-silicon molar ratio is increased to above 1.5. Molecular dynamics simulations elucidate the mechanistic underpinnings of the brittle-to-ductile transition governed by atomic bonding and lithiation-induced toughening. Our results reveal the high damage tolerance in amorphous lithium-rich silicon alloys and have important implications for the development of durable rechargeable batteries. PMID:26400671

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

    Science.gov (United States)

    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…

  2. Burnout in a high heat-flux boiling system with an impinging jet

    International Nuclear Information System (INIS)

    Monde, M.; Katto, Y.

    1978-01-01

    An experimental study has been made on the fully-developed nucleate boiling at atmospheric pressure in a simple forced-convection boiling system, which consists of a heated flat surface and a small, high-speed jet of water or of freon-113 impinging on the heated surface. A generalized correlation for burnout heat flux data, that is applied to either water or freon-113 is successfully evolved, and it is shown that surface tension has an important role for the onset of burnout phenomenon, not only in the ordinary pool boiling, but also in the present boiling system with a forced flow. (author)

  3. High-efficient solar cells with porous silicon

    International Nuclear Information System (INIS)

    Migunova, A.A.

    2002-01-01

    It has been shown that the porous silicon is multifunctional high-efficient coating on silicon solar cells, modifies its surface and combines in it self antireflection and passivation properties., The different optoelectronic effects in solar cells with porous silicon were considered. The comparative parameters of uncovered photodetectors also solar cells with porous silicon and other coatings were resulted. (author)

  4. 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…

  5. Burnout: Recognize and Reverse.

    Science.gov (United States)

    Anne, Samantha

    2014-07-01

    Physician burnout may be underrecognized and can cause significant detrimental effects on personal health and job satisfaction. Burnout has been associated with medical errors, alcohol and drug abuse, and neglect and abandonment of career goals. With self-awareness, development of coping mechanisms, and the adoption of a strong social and professional support network, burnout can be combated. This article focuses on recognizing characteristics of burnout and providing strategies to cope to avoid reaching a high degree of burnout. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

  6. Amorphous silicon as high index photonic material

    Science.gov (United States)

    Lipka, T.; Harke, A.; Horn, O.; Amthor, J.; Müller, J.

    2009-05-01

    Silicon-on-Insulator (SOI) photonics has become an attractive research topic within the area of integrated optics. This paper aims to fabricate SOI-structures for optical communication applications with lower costs compared to standard fabrication processes as well as to provide a higher flexibility with respect to waveguide and substrate material choice. Amorphous silicon is deposited on thermal oxidized silicon wafers with plasma-enhanced chemical vapor deposition (PECVD). The material is optimized in terms of optical light transmission and refractive index. Different a-Si:H waveguides with low propagation losses are presented. The waveguides were processed with CMOS-compatible fabrication technologies and standard DUV-lithography enabling high volume production. To overcome the large mode-field diameter mismatch between incoupling fiber and sub-μm waveguides three dimensional, amorphous silicon tapers were fabricated with a KOH etched shadow mask for patterning. Using ellipsometric and Raman spectroscopic measurements the material properties as refractive index, layer thickness, crystallinity and material composition were analyzed. Rapid thermal annealing (RTA) experiments of amorphous thin films and rib waveguides were performed aiming to tune the refractive index of the deposited a-Si:H waveguide core layer after deposition.

  7. [Professional burnout among university and high school teachers--comparative study].

    Science.gov (United States)

    Swietochowski, Waldemar

    2011-01-01

    Professional burnout is a set of negative emotional and behavioral symptoms, observed in workers of widely understood human service occupations, including teachers. In spite of the considerable number of studies of burnout in teachers, a few of them concern university teachers. The aim of the article was to estimate the degree of burning threat in this professional group and to analyze individual determinants and dynamics of burning out in academic teachers. Gender, age, personality traits and temperament traits were given the status of main factors in the study. The role of the perceived social support was also analyzed. 97 academic workers of three state universities (University, Medical University and Technical University) in Łódź took part in the study; 100 teachers of high schools formed a comparative group. MBI General Survey was applied to measure dependent variables (burnout and its three components: Emotional Exhaustion, Cinicism and Professional Efficacy). The level of factors was measured with standard psychological tests: NEO-FFI and FCZ-KT. The Scale of Perceived Social Support was also applied. The results show considerably lower threat of the burning out syndrome in university than in high school teachers. Among individual factors only two temperament traits (emotional reactivity and perseveration) and one personality trait (extroversion) seem to be important determinants of professional burnout. The perceived social support does not prevent the progress of burnout syndrome. Based on the obtained results several practical conclusions were formulated. They refer mainly to preventive training for beginners in teaching and changes in the organization of academic teachers' work.

  8. Burnout mechanizms

    International Nuclear Information System (INIS)

    Kh'yuitt, G.

    1980-01-01

    Different causes of the burnout are reviewed. Possible burnout mechanism are enumerated. Burnout at pool boaling is compared with burnout under forced convection. Experiments on burnout visualization and measurement of the consumption in the film at burnout are described. The entrainment diagram is introduced, and its analytical presentation is discussed. Different burnout zones are considered and the notion of controlled precipitation is mentioned. The application of the technique of annular flows modelling is described [ru

  9. [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.

  10. Nuclear radiation detectors using high resistivity neutron transmutation doped silicon

    International Nuclear Information System (INIS)

    Gessner, T.; Irmer, K.

    1983-01-01

    A method for the production of semiconductor detectors based on high resistivity n-type silicon is described. The n-type silicon is produced by neutron irradiation of p-type silicon. The detectors are produced by planar technique. They are suitable for the spectrometry of alpha particles and for the pulse count measurement of beta particles at room temperature. (author)

  11. Burnout among physicians

    OpenAIRE

    Romani, Maya; Ashkar, Khalil

    2014-01-01

    Burnout is a common syndrome seen in healthcare workers, particularly physicians who are exposed to a high level of stress at work; it includes emotional exhaustion, depersonalization, and low personal accomplishment. Burnout among physicians has garnered significant attention because of the negative impact it renders on patient care and medical personnel. Physicians who had high burnout levels reportedly committed more medical errors. Stress management programs that range from relaxation to ...

  12. Highly efficient silicon light emitting diode

    NARCIS (Netherlands)

    Le Minh, P.; Holleman, J.; Wallinga, Hans

    2002-01-01

    In this paper, we describe the fabrication, using standard silicon processing techniques, of silicon light-emitting diodes (LED) that efficiently emit photons with energy around the silicon bandgap. The improved efficiency had been explained by the spatial confinement of charge carriers due to a

  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. High surface area silicon materials: fundamentals and new technology.

    Science.gov (United States)

    Buriak, Jillian M

    2006-01-15

    Crystalline silicon forms the basis of just about all computing technologies on the planet, in the form of microelectronics. An enormous amount of research infrastructure and knowledge has been developed over the past half-century to construct complex functional microelectronic structures in silicon. As a result, it is highly probable that silicon will remain central to computing and related technologies as a platform for integration of, for instance, molecular electronics, sensing elements and micro- and nanoelectromechanical systems. Porous nanocrystalline silicon is a fascinating variant of the same single crystal silicon wafers used to make computer chips. Its synthesis, a straightforward electrochemical, chemical or photochemical etch, is compatible with existing silicon-based fabrication techniques. Porous silicon literally adds an entirely new dimension to the realm of silicon-based technologies as it has a complex, three-dimensional architecture made up of silicon nanoparticles, nanowires, and channel structures. The intrinsic material is photoluminescent at room temperature in the visible region due to quantum confinement effects, and thus provides an optical element to electronic applications. Our group has been developing new organic surface reactions on porous and nanocrystalline silicon to tailor it for a myriad of applications, including molecular electronics and sensing. Integration of organic and biological molecules with porous silicon is critical to harness the properties of this material. The construction and use of complex, hierarchical molecular synthetic strategies on porous silicon will be described.

  15. 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)

  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. Burnout in a high heat flux boiling system with forced supply of liquid through a plane jet

    International Nuclear Information System (INIS)

    Katto, Yoshiro; Ishii, Kazunori.

    1978-01-01

    As for pool boiling, the non-dimensional formula for the burnout heat flux of a simple, basic boiling system has been obtained. On the other hand, in forced convection boiling, the studies on the burnout in forced flow boiling in a channel have been continued, but the derivation of a non-dimensional formula applicable generally is far away from the realization because the phenomena are too complex. Accordingly, in this study, the result of the experiment on the burnout of a boiling system to which liquid is supplied by the plane jet flowing out of a thin rectangular nozzle installed near the front edge of a rectangular heating surface is reported. The experimental apparatus is described, and the experiment was carried out in the ranges of two jet thicknesses at the nozzle outlet, two incident angles of jet and from 1.5 to 15 m/s of jet velocity. Burnout occurs under the situation of sufficiently developed nuclear boiling. A part of the liquid supplied from a plane jet is blown apart by the vapor blowing out of the nuclear boiling liquid layer covering the heating surface in the nuclear boiling with sufficiently developed high heat flux. However, the nuclear boiling liquid layer itself continues to exist on the heating surface till burnout occurs. Only the entering velocity of the plane jet affects burnout heat flux. (Kako, I.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Pradeepkumar, Aiswarya; Mishra, Neeraj; Kermany, Atieh Ranjbar; Iacopi, Francesca [Queensland Micro and Nanotechnology Centre and Environmental Futures Research Institute, Griffith University, Nathan QLD 4111 (Australia); Boeckl, John J. [Materials and Manufacturing Directorate, Air Force Research Laboratories, Wright-Patterson Air Force Base, Ohio 45433 (United States); Hellerstedt, Jack; Fuhrer, Michael S. [Monash Centre for Atomically Thin Materials, Monash University, Monash, VIC 3800 (Australia)

    2016-07-04

    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.

  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. High temperature deformation of silicon steel

    International Nuclear Information System (INIS)

    Rodríguez-Calvillo, Pablo; Houbaert, Yvan; Petrov, Roumen; Kestens, Leo; Colás, Rafael

    2012-01-01

    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 −1 with reductions of 25, 35 and 75% at temperatures varying from 800 to 1100 °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 °C. The texture of the equiaxed and elongated grains was found to vary with the increase of deformation and temperature, as the γ-fibre tends to disappear and the α-fibre to increase towards the higher temperature range. -- Highlights: ► The plastic deformation of a silicon containing steel is studied by plane strain compression. ► Equiaxed and elongated grains develop in different regions of the sample due to recrystallization. ► Texture, by EBSD, is revealed to be similar in either type of grains.

  1. Burnout, work engagement and workaholism among highly educated employees: Profiles, antecedents and outcomes

    Directory of Open Access Journals (Sweden)

    Hely Innanen

    2014-06-01

    Full Text Available The present study examined the longitudinal profiles of burnout, engagement and workaholism among highly educated employees. First, the latent profile modeling indicated two latent classes: Engaged and Exhausted-Workaholic. Second, the results revealed that employees with the Engaged profile experienced high levels of energy and dedication, whereas employees with the Exhausted-Workaholic profile experienced exhaustion, cynicism and workaholism. Social pessimism in the transition from high education to work predicted poor subjective well-being at work. Further, workaholism decreased during the career among members of the Exhausted-Workaholic profile suggesting positive direction during career. Finally, Engaged employees experienced detachment and relaxation, life satisfaction and rewards.

  2. Production of high specific activity silicon-32

    International Nuclear Information System (INIS)

    Phillips, D.R.; Brzezinski, M.A.

    1998-01-01

    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 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 32 Si in biological oceanographic research related to global climate modeling. The first objective was met by developing targetry for proton spallation production of 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

  3. Microcapillary Features in Silicon Alloyed High-Strength Cast Iron

    Directory of Open Access Journals (Sweden)

    R.K. Hasanli

    2017-04-01

    Full Text Available Present study explores features of silicon micro capillary in alloyed high-strength cast iron with nodular graphite (ductile iron produced in metal molds. It identified the nature and mechanism of micro liquation of silicon in a ductile iron alloyed with Nickel and copper, and demonstrated significant change of structural-quality characteristics. It was concluded that the matrix of alloyed ductile iron has a heterogeneous structure with cross reinforcement and high-silicon excrement areas.

  4. 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…

  5. 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

    2016-02-03

    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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Do perceived high performance work systems influence the relationship between emotional labour, burnout and intention to leave? A study of Australian nurses.

    Science.gov (United States)

    Bartram, Timothy; Casimir, Gian; Djurkovic, Nick; Leggat, Sandra G; Stanton, Pauline

    2012-07-01

    The purpose of this article was to explore the relationships between perceived high performance work systems, emotional labour, burnout and intention to leave among nurses in Australia. Previous studies show that emotional labour and burnout are associated with an increase in intention to leave of nurses. There is evidence that high performance work systems are in association with a decrease in turnover. There are no previous studies that examine the relationship between high performance work systems and emotional labour. A cross-sectional, correlational survey. The study was conducted in Australia in 2008 with 183 nurses. Three hypotheses were tested with validated measures of emotional labour, burnout, intention to leave, and perceived high performance work systems. Principal component analysis was used to examine the structure of the measures. The mediation hypothesis was tested using Baron and Kenny's procedure and the moderation hypothesis was tested using hierarchical regression and the product-term. Emotional labour is positively associated with both burnout and intention to leave. Burnout mediates the relationship between emotional labour and intention to leave. Perceived high performance work systems negatively moderates the relationship between emotional labour and burnout. Perceived high performance work systems not only reduces the strength of the negative effect of emotional labour on burnout but also has a unique negative effect on intention to leave. Ensuring effective human resource management practice through the implementation of high performance work systems may reduce the burnout associated with emotional labour. This may assist healthcare organizations to reduce nurse turnover. © 2012 Blackwell Publishing Ltd.

  7. High speed all-silicon optical modulator

    International Nuclear Information System (INIS)

    Marris-Morini, Delphine; Le Roux, Xavier; Pascal, Daniel; Vivien, Laurent; Cassan, Eric; Fedeli, Jean Marc; Damlencourt, Jean Francois; Bouville, David; Palomo, Jose; Laval, Suzanne

    2006-01-01

    Electrorefractive effect is experimentally demonstrated in an all-silicon optical structure. A highly doped Si P + layer is embedded in the intrinsic region of a PIN diode integrated in a SOI waveguide. Holes are confined at equilibrium around the P + layer. By applying a reverse bias to the diode, electrical field sweeps the carriers out of the active region. Free carrier concentration variations are responsible for local refractive index variations leading to an effective index variation of the waveguide optical mode and to an optical absorption variation. As a figure of merit, the product V π L π , determined from the measured effective index variation, is equal to 3.1 V cm. Furthermore, the device performances have theoretically been investigated. Estimations show that V π L π as small as 1 V cm are feasible using optimized structures. Response times lower than 2 ps are predicted, which gives the possibility to achieve very high-speed modulation. Furthermore, a temperature increases from 300 to 400 K does not change the index variation amplitude, and despite the carrier mobility reduction, response times are still lower than 2 ps

  8. Hydrophilic functionalized silicon nanoparticles produced by high energy ball milling

    Science.gov (United States)

    Hallmann, Steffen

    The mechanochemical synthesis of functionalized silicon nanoparticles using High Energy Ball Milling (HEBM) is described. This method facilitates the fragmentation of mono crystalline silicon into the nanometer regime and the simultaneous surface functionalization of the formed particles. The surface functionalization is induced by the reaction of an organic liquid, such as alkynes and alkenes with reactive silicon sites. This method can be applied to form water soluble silicon nanoparticles by lipid mediated micelle formation and the milling in organic liquids containing molecules with bi-functional groups, such as allyl alcohol. Furthermore, nanometer sized, chloroalkyl functionalized particles can be synthesized by milling the silicon precursor in the presence of an o-chloroalkyne with either alkenes or alkynes as coreactants. This process allows tuning of the concentration of the exposed, alkyl linked chloro groups, simply by varying the relative amounts of the coreactant. The silicon nanoparticles that are formed serve as the starting point for a wide variety of chemical reactions, which may be used to alter the surface properties of the functionalized nanoparticles. Finally, the use of functionalized silicon particles for the production of superhydrophobic films is described. Here HEBM proves to be an efficient method to produce functionalized silicon particles, which can be deposited to form a stable coating exhibiting superhydrophobic properties. The hydrophobicity of the silicon film can be tuned by the milling time and thus the resulting surface roughness of the films.

  9. 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.

  10. 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…

  11. Study of mechanism of burnout in a high heat-flux boiling system with an impinging jet

    International Nuclear Information System (INIS)

    Katto, Y.; Monde, M.

    1974-01-01

    Nucleate boiling at very high heat fluxes was created on a heated surface covered with a flowing film of saturated water at atmospheric pressure being maintained by a small circular jet of water held at the center of the heated surface. It was found that increasing the heat flux led to a limiting state of flow where the splashing of droplets from the heated surface was no longer increased being kept constant until burnout appeared; and that there was a close relation between the burnout heat flux and the jet velocity. A flow model, which can explain the characteristics of this boiling system, is proposed. It is suggested that the burnout may be connected with the separation of a liquid flow from the heated surface accompanied with the effusion of vapor. (U.S.)

  12. Silicon Photomultiplier Performance in High ELectric Field

    Science.gov (United States)

    Montoya, J.; Morad, J.

    2016-12-01

    Roughly 27% of the universe is thought to be composed of dark matter. The Large Underground Xenon (LUX) relies on the emission of light from xenon atoms after a collision with a dark matter particle. After a particle interaction in the detector, two things can happen: the xenon will emit light and charge. The charge (electrons), in the liquid xenon needs to be pulled into the gas section so that it can interact with gas and emit light. This allows LUX to convert a single electron into many photons. This is done by applying a high voltage across the liquid and gas regions, effectively ripping electrons out of the liquid xenon and into the gas. The current device used to detect photons is the photomultiplier tube (PMT). These devices are large and costly. In recent years, a new technology that is capable of detecting single photons has emerged, the silicon photomultiplier (SiPM). These devices are cheaper and smaller than PMTs. Their performance in a high electric fields, such as those found in LUX, are unknown. It is possible that a large electric field could introduce noise on the SiPM signal, drowning the single photon detection capability. My hypothesis is that SiPMs will not observe a significant increase is noise at an electric field of roughly 10kV/cm (an electric field within the range used in detectors like LUX). I plan to test this hypothesis by first rotating the SiPMs with no applied electric field between two metal plates roughly 2 cm apart, providing a control data set. Then using the same angles test the dark counts with the constant electric field applied. Possibly the most important aspect of LUX, is the photon detector because it's what detects the signals. Dark matter is detected in the experiment by looking at the ratio of photons to electrons emitted for a given interaction in the detector. Interactions with a low electron to photon ratio are more like to be dark matter events than those with a high electron to photon ratio. The ability to

  13. 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…

  14. Burnout experiment in subcooled forced-convection boiling of water for beam dumps of a high power neutral beam injector

    International Nuclear Information System (INIS)

    Horiike, Hiroshi; Kuriyama, Masaaki; Morita, Hiroaki

    1982-01-01

    Experimental studies were made on burnout heat flux in highly subcooled forced-convection boiling of water for the design of beam dumps of a high power neutral beam injector for Japan Atomic Energy Research Institute Tokamak-60. These dumps are composed of many circular tubes with two longitudinal fins. The tube was irradiated with nonuniformly distributed hydrogen ion beams of 120 to 200 kW for as long as 10 s. The coolant water was circulated at flow velocities of 3 to 7.5 m/s at exit pressures of 0.4 to 0.9 MPa. The burnout and film-boiling data were obtained at local heat fluxes of 8 to 15 MW/m 2 . These values were as high as 2.5 times larger than those for the circumferentially uniform heat flux case with the same parameters. These data showed insensitivity to local subcooling as well as to pressure, and simple burnout correlations were derived. From these results, the beam dumps have been designed to receive energetic beam fluxes of as high as 5 MW/m 2 with a margin of a factor of 2 for burnout

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...... 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....

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

    DEFF Research Database (Denmark)

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

    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...... of the ultra-fast nonlinear response of silicon photonic waveguides. These chips offer ultra-broadband wavelength operation, ultra-high timing resolution and ultra-fast response, and when used appropriately offer energy-efficient switching. In this presentation we review some all-optical functionalities based...... 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...

  17. Brain inspired high performance electronics on flexible silicon

    KAUST Repository

    Sevilla, Galo T.; Rojas, Jhonathan Prieto; Hussain, Muhammad Mustafa

    2014-01-01

    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

  18. Iron solubility in highly boron-doped silicon

    International Nuclear Information System (INIS)

    McHugo, S.A.; McDonald, R.J.; Smith, A.R.; Hurley, D.L.; Weber, E.R.

    1998-01-01

    We have directly measured the solubility of iron in high and low boron-doped silicon using instrumental neutron activation analysis. Iron solubilities were measured at 800, 900, 1000, and 1100thinsp degree C in silicon doped with either 1.5x10 19 or 6.5x10 14 thinspboronthinspatoms/cm 3 . We have measured a greater iron solubility in high boron-doped silicon as compared to low boron-doped silicon, however, the degree of enhancement is lower than anticipated at temperatures >800thinsp degree C. The decreased enhancement is explained by a shift in the iron donor energy level towards the valence band at elevated temperatures. Based on this data, we have calculated the position of the iron donor level in the silicon band gap at elevated temperatures. We incorporate the iron energy level shift in calculations of iron solubility in silicon over a wide range of temperatures and boron-doping levels, providing a means to accurately predict iron segregation between high and low boron-doped silicon. copyright 1998 American Institute of Physics

  19. Introduction of high oxygen concentrations into silicon wafers by high-temperature diffusion

    International Nuclear Information System (INIS)

    Casse, G.; Glaser, M.; Lemeilleur, F.; Ruzin, A.; Wegrzecki, M.

    1999-01-01

    The tolerance of silicon detectors to hadron irradiation can be improved by the introduction of a high concentration of oxygen into the starting material. High-resistivity Floating-Zone (FZ) silicon is required for detectors used in particle physics applications. A significantly high oxygen concentration (>10 17 atoms cm -3 ) cannot readily be achieved during the FZ silicon refinement. The diffusion of oxygen at elevated temperatures from a SiO 2 layer grown on both sides of a silicon wafer is a simple and effective technique to achieve high and uniform concentrations of oxygen throughout the bulk of a 300 μm thick silicon wafer

  20. Process development for high-efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Gee, J.M.; Basore, P.A.; Buck, M.E.; Ruby, D.S.; Schubert, W.K.; Silva, B.L.; Tingley, J.W.

    1991-12-31

    Fabrication of high-efficiency silicon solar cells in an industrial environment requires a different optimization than in a laboratory environment. Strategies are presented for process development of high-efficiency silicon solar cells, with a goal of simplifying technology transfer into an industrial setting. The strategies emphasize the use of statistical experimental design for process optimization, and the use of baseline processes and cells for process monitoring and quality control. 8 refs.

  1. High frequency guided wave propagation in monocrystalline silicon wafers

    OpenAIRE

    Pizzolato, M.; Masserey, B.; Robyr, J. L.; Fromme, P.

    2017-01-01

    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...

  2. Functional silicone copolymers and elastomers with high dielectric permittivity

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Daugaard, Anders Egede; Hvilsted, Søren

    Dielectric elastomers (DEs) 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. DEs consist of a soft and thin elastomeric film sandwiched between compliant electrodes......, thereby forming a capacitor [1]. Silicone elastomers are one of the most used materials for DEs due to their high efficiency, fast response times and low viscous losses. The major disadvantage of silicone elastomers is that they possess relatively low dielectric permittivity, which means that a high...... electrical field is necessary to operate the DE. The necessary electrical field can be lowered by creating silicone elastomers with higher dielectric permittivity, i.e. with a higher energy density.The aim of this work is to create new and improved silicone elastomers with high dielectric permittivity...

  3. Development of large area, high efficiency amorphous silicon solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, K.S.; Kim, S.; Kim, D.W. [Yu Kong Taedok Institute of Technology (Korea, Republic of)

    1996-02-01

    The objective of the research is to develop the mass-production technologies of high efficiency amorphous silicon solar cells in order to reduce the costs of solar cells and dissemination of solar cells. Amorphous silicon solar cell is the most promising option of thin film solar cells which are relatively easy to reduce the costs. The final goal of the research is to develop amorphous silicon solar cells having the efficiency of 10%, the ratio of light-induced degradation 15% in the area of 1200 cm{sup 2} and test the cells in the form of 2 Kw grid-connected photovoltaic system. (author) 35 refs., 8 tabs., 67 figs.

  4. Corrosion of silicon nitride in high temperature alkaline solutions

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Liyan, E-mail: liyan.qiu@cnl.ca; Guzonas, Dave A.; Qian, Jing

    2016-08-01

    The corrosion of silicon nitride (Si{sub 3}N{sub 4}) in alkaline solutions was studied at temperatures from 60 to 300 °C. Si{sub 3}N{sub 4} experienced significant corrosion above 100 °C. The release rates of silicon and nitrogen follow zero order reaction kinetics and increase with increasing temperature. The molar ratio of dissolved silicon and nitrogen species in the high temperature solutions is the same as that in the solid phase (congruent dissolution). The activation energy for silicon and nitrogen release rates is 75 kJ/mol which agrees well with that of silica dissolution. At 300 °C, the release of aluminum is observed and follows first order reaction kinetics while other minor constituents including Ti and Y are highly enriched on the corrosion films due to the low solubility of their oxides.

  5. 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.

  6. Burnout: need help?

    Science.gov (United States)

    Gulalp, Betul; Karcioglu, Ozgur; Sari, Azade; Koseoglu, Zikret

    2008-12-05

    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). 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. There were no relation between Burnout scores and supplementary work, marital status, number of children, occupation, salary, private life satisfaction, except for career satisfaction. 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.

  7. Thin silicon foils produced by epoxy-induced spalling of silicon for high efficiency solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Martini, R., E-mail: roberto.martini@imec.be [Department of Electrical Engineering, KU Leuven, Kasteelpark 10, 3001 Leuven (Belgium); imec, Kapeldreef 75, 3001 Leuven (Belgium); Kepa, J.; Stesmans, A. [Department of Physics, KU Leuven, Celestijnenlaan 200 D, 3001 Leuven (Belgium); Debucquoy, M.; Depauw, V.; Gonzalez, M.; Gordon, I. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Poortmans, J. [Department of Electrical Engineering, KU Leuven, Kasteelpark 10, 3001 Leuven (Belgium); imec, Kapeldreef 75, 3001 Leuven (Belgium); Universiteit Hasselt, Martelarenlaan 42, B-3500 Hasselt (Belgium)

    2014-10-27

    We report on the drastic improvement of the quality of thin silicon foils produced by epoxy-induced spalling. In the past, researchers have proposed to fabricate silicon foils by spalling silicon substrates with different stress-inducing materials to manufacture thin silicon solar cells. However, the reported values of effective minority carrier lifetime of the fabricated foils remained always limited to ∼100 μs or below. In this work, we investigate epoxy-induced exfoliated foils by electron spin resonance to analyze the limiting factors of the minority carrier lifetime. These measurements highlight the presence of disordered dangling bonds and dislocation-like defects generated by the exfoliation process. A solution to remove these defects compatible with the process flow to fabricate solar cells is proposed. After etching off less than 1 μm of material, the lifetime of the foil increases by more than a factor of 4.5, reaching a value of 461 μs. This corresponds to a lower limit of the diffusion length of more than 7 times the foil thickness. Regions with different lifetime correlate well with the roughness of the crack surface which suggests that the lifetime is now limited by the quality of the passivation of rough surfaces. The reported values of the minority carrier lifetime show a potential for high efficiency (>22%) thin silicon solar cells.

  8. Thin silicon foils produced by epoxy-induced spalling of silicon for high efficiency solar cells

    International Nuclear Information System (INIS)

    Martini, R.; Kepa, J.; Stesmans, A.; Debucquoy, M.; Depauw, V.; Gonzalez, M.; Gordon, I.; Poortmans, J.

    2014-01-01

    We report on the drastic improvement of the quality of thin silicon foils produced by epoxy-induced spalling. In the past, researchers have proposed to fabricate silicon foils by spalling silicon substrates with different stress-inducing materials to manufacture thin silicon solar cells. However, the reported values of effective minority carrier lifetime of the fabricated foils remained always limited to ∼100 μs or below. In this work, we investigate epoxy-induced exfoliated foils by electron spin resonance to analyze the limiting factors of the minority carrier lifetime. These measurements highlight the presence of disordered dangling bonds and dislocation-like defects generated by the exfoliation process. A solution to remove these defects compatible with the process flow to fabricate solar cells is proposed. After etching off less than 1 μm of material, the lifetime of the foil increases by more than a factor of 4.5, reaching a value of 461 μs. This corresponds to a lower limit of the diffusion length of more than 7 times the foil thickness. Regions with different lifetime correlate well with the roughness of the crack surface which suggests that the lifetime is now limited by the quality of the passivation of rough surfaces. The reported values of the minority carrier lifetime show a potential for high efficiency (>22%) thin silicon solar cells.

  9. High-gain bipolar detector on float-zone silicon

    Science.gov (United States)

    Han, D. J.; Batignani, G.; Del Guerra, A.; Dalla Betta, G.-F.; Boscardin, M.; Bosisio, L.; Giorgi, M.; Forti, F.

    2003-10-01

    Since the float-zone (FZ) silicon has lower contaminations and longer minority-carrier lifetime than those in Czochralski silicon and other semiconductor materials, it has potential advantages to fabricate bipolar detectors on the high-purity FZ silicon substrate to achieve a high gain at ultra-low-signal levels. The authors present preliminary experimental results on a bipolar detector fabricated on an unusual high-purity FZ silicon substrate. A backside gettering layer of phosphorus-doped polysilicon was employed to preserve the long carrier lifetime of the high-purity FZ silicon. The device has been investigated in the detection of a continuous flux of X-ray and infrared light. The bipolar detector with a circular emitter of 2 mm diameter has demonstrated high gains up to 3820 for 22 keV X-ray from a 1 mCi Cd radioactive source (the X-ray photon flux, received by the detector is estimated to be ˜7.77×10 4/s). High gain up to 4400 for 0.17 nW light with a wavelength of 0.83 μm has been observed for the same device.

  10. High-gain bipolar detector on float-zone silicon

    International Nuclear Information System (INIS)

    Han, D.J.; Batignani, G.; Guerra, A.D.A. Del; Dalla Betta, G.-F.; Boscardin, M.; Bosisio, L.; Giorgi, M.; Forti, F.

    2003-01-01

    Since the float-zone (FZ) silicon has lower contaminations and longer minority-carrier lifetime than those in Czochralski silicon and other semiconductor materials, it has potential advantages to fabricate bipolar detectors on the high-purity FZ silicon substrate to achieve a high gain at ultra-low-signal levels. The authors present preliminary experimental results on a bipolar detector fabricated on an unusual high-purity FZ silicon substrate. A backside gettering layer of phosphorus-doped polysilicon was employed to preserve the long carrier lifetime of the high-purity FZ silicon. The device has been investigated in the detection of a continuous flux of X-ray and infrared light. The bipolar detector with a circular emitter of 2 mm diameter has demonstrated high gains up to 3820 for 22 keV X-ray from a 1 mCi Cd radioactive source (the X-ray photon flux, received by the detector is estimated to be ∼7.77x10 4 /s). High gain up to 4400 for 0.17 nW light with a wavelength of 0.83 μm has been observed for the same device

  11. Burnout calculation

    International Nuclear Information System (INIS)

    Li, D.

    1980-01-01

    Reviewed is the effect of heat flux of different system parameters on critical density in order to give an initial view on the value of several parameters. A thorough analysis of different equations is carried out to calculate burnout is steam-water flows in uniformly heated tubes, annular, and rectangular channels and rod bundles. Effect of heat flux density distribution and flux twisting on burnout and storage determination according to burnout are commended [ru

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Tianyue

    2018-01-23

    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.

  14. [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.

  15. 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

  16. 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...... elastomers. A decrease in Young’s modulus, however, is often accompanied by the loss of mechanical stability and thereby the lifetime of the DE. New soft elastomer matrices with high dielectric permittivity and low Young’s modulus, with no loss of mechanical stability, were prepared by two different...... approaches using chloropropyl-functional silicone polymers. The first approach was based on synthesised chloropropyl-functional copolymers that were cross-linkable and thereby formed the basis of new silicone networks with high dielectric permittivity (e.g. a 43% increase). These networks were soft without...

  17. High-Current-Density Vertical-Tunneling Transistors from Graphene/Highly Doped Silicon Heterostructures.

    Science.gov (United States)

    Liu, Yuan; Sheng, Jiming; Wu, Hao; He, Qiyuan; Cheng, Hung-Chieh; Shakir, Muhammad Imran; Huang, Yu; Duan, Xiangfeng

    2016-06-01

    Scalable fabrication of vertical-tunneling transistors is presented based on heterostructures formed between graphene, highly doped silicon, and its native oxide. Benefiting from the large density of states of highly doped silicon, the tunneling transistors can deliver a current density over 20 A cm(-2) . This study demonstrates that the interfacial native oxide plays a crucial role in governing the carrier transport in graphene-silicon heterostructures. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Teacher Burnout.

    Science.gov (United States)

    USA Today, 1985

    1985-01-01

    Teacher burnout is characterized by three factors: emotional exhaustion and fatigue; negative, cynical attitudes towards students; and the loss of feelings of accomplishment on the job. Important predictors of burnout include a lack of participation in decision-making, inappropriate job expectations, a lack of teacher autonomy, and role conflict.…

  19. Design of a charge sensitive preamplifier on high resistivity silicon

    International Nuclear Information System (INIS)

    Radeka, V.; Rehak, P.; Rescia, S.; Gatti, E.; Longoni, A.; Sampietro, M.; Holl, P.; Strueder, L.; Kemmer, J.

    1987-01-01

    A low noise, fast charge sensitive preamplifier was designed on high resistivity, detector grade silicon. It is built at the surface of a fully depleted region of n-type silicon. This allows the preamplifier to be placed very close to a detector anode. The preamplifier uses the classical input cascode configuration with a capacitor and a high value resistor in the feedback loop. The output stage of the preamplifier can drive a load up to 20pF. The power dissipation of the preamplifier is 13mW. The amplifying elements are ''Single Sided Gate JFETs'' developed especially for this application. Preamplifiers connected to a low capacitance anode of a drift type detector should achieve a rise time of 20ns and have an equivalent noise charge (ENC), after a suitable shaping, of less than 50 electrons. This performance translates to a position resolution better than 3μm for silicon drift detectors. 6 refs., 9 figs

  20. 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.

  1. 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.

  2. 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.

  3. Autoionizing states in highly ionized oxygen, fluorine and silicon

    International Nuclear Information System (INIS)

    Forester, J.P.; Peterson, R.S.; Griffin, P.M.; Pegg, D.J.; Haselton, H.H.; Liao, K.H.; Sellin, I.A.; Mowat, J.R.; Thoe, R.S.

    1975-01-01

    Autoionizing states in high Z 3-electron ions associated with core excited configurations of the type 1s2snl and 1s2pnl are reported. The electron decay-in-flight spectra of lithium-like oxygen, fluorine, and silicon ions are presented. Initial beam energies of 6.75-MeV oxygen and fluorine ions and 22.5-MeV silicon ions were used. Stripping and excitation were done by passing the beams through a thin carbon foil. The experimental technique is described. 4 figs, 1 table, 7 refs

  4. Simple processing of high efficiency silicon solar cells

    International Nuclear Information System (INIS)

    Hamammu, I.M.; Ibrahim, K.

    2006-01-01

    Cost effective photovoltaic devices have been an area research since the development of the first solar cells, as cost is the major factor in their usage. Silicon solar cells have the biggest share in the photovoltaic market, though silicon os not the optimal material for solar cells. This work introduces a simplified approach for high efficiency silicon solar cell processing, by minimizing the processing steps and thereby reducing cost. The suggested procedure might also allow for the usage of lower quality materials compared to the one used today. The main features of the present work fall into: simplifying the diffusion process, edge shunt isolation and using acidic texturing instead of the standard alkaline processing. Solar cells of 17% efficiency have been produced using this procedure. Investigations on the possibility of improving the efficiency and using less quality material are still underway

  5. High-Tc superconducting antenna-coupled microbolometer on silicon

    Science.gov (United States)

    Rice, Joseph P.; Grossman, Erich N.; Borcherdt, L. J.; Rudman, D. A.

    1994-05-01

    A process is described for fabricating antenna-coupled resistive-edge microbolometers based on the high-Tc superconductor YBa2Cu3O7 (YBCO) on silicon. The YBCO and a buffer layer of yttria-stabilized zirconia (YSZ) were grown epitaxially on silicon to minimize excess electrical noise. A silicon-micromachined YBCO/YSZ air-bridge was incorporated to minimize the thermal conductance and the heat capacity. The thermal conductance of the air-bridge was measured to be 3 X 10-6 W/K at a temperature of 100 K. At an operating temperature of 89 K, the detector is estimated to have a response time of 2 microsecond(s) , a responsivity of the 1000 V/W range, and a noise-equivalent power in the 10-12 W/Hz1/2 range at 1000 Hz.

  6. High-{Tc} superconducting antenna-coupled microbolometer on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Rice, J.P.; Grossman, E.N.; Borcherdt, L.J.; Rudman, D.A. [National Inst. of Standards and Technology, Boulder, CO (United States). Cryoelectronic Metrology Group

    1994-12-31

    A process is described for fabricating antenna-coupled resistive-edge microbolometers based on the high-{Tc} superconductor YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) on silicon. The YBCO and a buffer layer of yttria-stabilized zirconia (YSZ) were grown epitaxially on silicon to minimize excess electrical noise. A silicon-micromachined YBCO/YSZ air-bridge was incorporated to minimize the thermal conductance and the heat capacity. The thermal conductance of the air-bridge was measured to be 3 {times} 10{sup {minus}6} W/K at a temperature of 100 K. At an operating temperature of 89 K, the detector is estimated to have a response time of 2 {micro}s, a responsivity in the 1,000 V/W range, and a noise-equivalent power (NEP) in the 10{sup {minus}12} W/Hz{sup 1/2} range at 1,000 Hz.

  7. 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...

  8. Suppressing segregation in highly phosphorus doped silicon monolayers

    NARCIS (Netherlands)

    Keizer, Joris; Kölling, Sebastian; Koenraad, Paul; Simmons, Michelle Y.

    2015-01-01

    Sharply defined dopant profiles and low resistivity are highly desired qualities in the microelectronic industry, and more recently, in the development of an all epitaxial Si:P based quantum computer. In this work, we use thin (monolayers thick) room temperature grown silicon layers, so-called

  9. Direct Electroplating on Highly Doped Patterned Silicon Wafers

    NARCIS (Netherlands)

    Vargas Llona, Laura Dolores; Jansen, Henricus V.; Elwenspoek, Michael Curt

    Nickel thin films have been electrodeposited directly on highly doped silicon wafers after removal of the native oxide layer. These substrates conduct sufficiently well to allow deposition using a periferical electrical contact on the wafer. Films 2 μm thick were deposited using a nickel sulfamate

  10. Process Characterization of Electrical Discharge Machining of Highly Doped Silicon

    Science.gov (United States)

    2012-06-01

    of mechanism is shown in Figure 2 showing the wire feed panel where the spool of 5 (DiBitonto, et...Uno High efficiency boring of monocrystalline silicon ingot by EDM RAM Si (P-type) conductivity 0.01 ohm-cm 1mm Cu pipe electrode, rotating at

  11. 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....

  12. [Emotional burnout syndrome and pedagogical styles in teachers of a medical high school].

    Science.gov (United States)

    Ivanova, E I; Ivanov, I V; Serdakova, K G

    2011-01-01

    The study involved 20 teachers of medical institutions who gave consent to be examined for emotional burnout syndrome (EBS). Diagnosis of moderate EBS was confirmed by relevant clinical tests and analysis of pedagogical communication style in 30% of the participants. The pedagogical style of teachers exhibiting no signs of burnout is characterized by personality-oriented model of communication with differential attitudes toward students and active interaction with them. Teachers presenting with EBS relied on the disciplinary model of communication prevailed by authoritarian and dictatorial behaviour lacking communicability and flexibility; these persons showed pronounced hyperreflexia.

  13. Radiation hardened high efficiency silicon space solar cell

    International Nuclear Information System (INIS)

    Garboushian, V.; Yoon, S.; Turner, J.

    1993-01-01

    A silicon solar cell with AMO 19% Beginning of Life (BOL) efficiency is reported. The cell has demonstrated equal or better radiation resistance when compared to conventional silicon space solar cells. Conventional silicon space solar cell performance is generally ∼ 14% at BOL. The Radiation Hardened High Efficiency Silicon (RHHES) cell is thinned for high specific power (watts/kilogram). The RHHES space cell provides compatibility with automatic surface mounting technology. The cells can be easily combined to provide desired power levels and voltages. The RHHES space cell is more resistant to mechanical damage due to micrometeorites. Micro-meteorites which impinge upon conventional cells can crack the cell which, in turn, may cause string failure. The RHHES, operating in the same environment, can continue to function with a similar crack. The RHHES cell allows for very efficient thermal management which is essential for space cells generating higher specific power levels. The cell eliminates the need for electrical insulation layers which would otherwise increase the thermal resistance for conventional space panels. The RHHES cell can be applied to a space concentrator panel system without abandoning any of the attributes discussed. The power handling capability of the RHHES cell is approximately five times more than conventional space concentrator solar cells

  14. Burnout and Work Engagement Among US Dentists.

    Science.gov (United States)

    Calvo, Jean Marie; Kwatra, Japneet; Yansane, Alfa; Tokede, Oluwabunmi; Gorter, Ronald C; Kalenderian, Elsbeth

    2017-06-30

    Burnout is a threat to patient safety. It relates to emotional exhaustion, depersonalization, and lack of personal accomplishment. Work engagement conversely composed of levels of vigor, dedication, and absorption in one's profession. The aim of this study was to examine burnout and work engagement among US dentists. This study used the extensively validated Maslach Burnout Inventory-Human Services Survey and Utrecht Work Engagement Scale to measure burnout in a self-administered survey of 167 US dentists who attended continuing education courses held in Boston, Pittsburg, Iowa City, and Las Vegas. The mean scores on the 3 subscales of Maslach Burnout Inventory-Human Services Survey and Utrecht Work Engagement Scale were computed. The interscale correlations between the components of burnout and work engagement were assessed using Pearson correlations. We used 1-way analysis of variance and independent 2 sample t tests to examine the relationship between burnout and work engagement across sex and various age categories. Prevalence of burnout in our study population was also computed. We observed that 13.2% of our study population experienced burnout and 16.2% of our study population was highly work engaged. There was a statistically significant, unadjusted association between burnout risk and work engagement (χ = 22.51, P work engagement. In this preliminary study, we observed some evidence of burnout among practicing US dentists. It is imperative that the dental profession understands this and works to promote professional practices that increase work engagement and decrease burnout.

  15. Decomposition of silicon carbide at high pressures and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Daviau, Kierstin; Lee, Kanani K. M.

    2017-11-01

    We measure the onset of decomposition of silicon carbide, SiC, to silicon and carbon (e.g., diamond) at high pressures and high temperatures in a laser-heated diamond-anvil cell. We identify decomposition through x-ray diffraction and multiwavelength imaging radiometry coupled with electron microscopy analyses on quenched samples. We find that B3 SiC (also known as 3C or zinc blende SiC) decomposes at high pressures and high temperatures, following a phase boundary with a negative slope. The high-pressure decomposition temperatures measured are considerably lower than those at ambient, with our measurements indicating that SiC begins to decompose at ~ 2000 K at 60 GPa as compared to ~ 2800 K at ambient pressure. Once B3 SiC transitions to the high-pressure B1 (rocksalt) structure, we no longer observe decomposition, despite heating to temperatures in excess of ~ 3200 K. The temperature of decomposition and the nature of the decomposition phase boundary appear to be strongly influenced by the pressure-induced phase transitions to higher-density structures in SiC, silicon, and carbon. The decomposition of SiC at high pressure and temperature has implications for the stability of naturally forming moissanite on Earth and in carbon-rich exoplanets.

  16. Low burnout risk and high engagement levels among oral and maxillofacial surgeons

    NARCIS (Netherlands)

    Gorter, R.C.; Jacobs, B.L.T.H.; Allard, R.H.B.

    2012-01-01

    Little is known about the well-being of oral and maxillofacial surgeons. The aim of this study was to measure the levels of burnout risk and the demanding work aspects of Dutch oral and maxillofacial surgeons, as well as the levels of positive work engagement and stimulating aspects of the work

  17. High mechanical Q-factor measurements on silicon bulk material

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Christian; Nawrodt, Ronny; Heinert, Daniel; Schroeter, Anja; Neubert, Ralf; Thuerk, Matthias; Vodel, Wolfgang; Seidel, Paul [Institut fuer Festkoerperphysik, Helmholtzweg 5, D-07743 Jena (Germany); Tuennermann, Andreas [Institut fuer Angewandte Physik, Albert-Einstein-Strasse 15, D-07745 Jena (Germany)

    2008-07-01

    The direct observation of gravitational waves is one of the biggest challenges in science. Current detectors are limited by different kinds of noise. One of the fundamental noise sources is thermal noise arising from the optical components. One of the most promising attempts to reduce the thermal noise contribution in future detectors will be the use of high Q-factor materials at cryogenic temperatures. Silicon seems to be the most interesting material due to its excellent optical and thermal properties. We present high Q-factor measurements on bulk samples of high purity silicon in a temperature range from 5 to 300 K. The sample dimensions vary between 76.2 mm x 12..75 mm. The Q-factor exceeds 4.10{sup 8} at 6 K. The influence of the crystal orientation, doping and the sample preparation on the Q-factor is discussed.

  18. Synthetic Strategies for High Dielectric Constant Silicone Elastomers

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt

    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...... extender’ that allowed for chemical modifications such as Cu- AAC. This route was promising for one-pot elastomer preparation and as a high dielectric constant additive to commercial silicone systems. The second approach used the borane-catalysed Piers-Rubinsztajn reaction to form spatially well...

  19. 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.

  20. Highly featured amorphous silicon nanorod arrays for high-performance lithium-ion batteries

    International Nuclear Information System (INIS)

    Soleimani-Amiri, Samaneh; Safiabadi Tali, Seied Ali; Azimi, Soheil; Sanaee, Zeinab; Mohajerzadeh, Shamsoddin

    2014-01-01

    High aspect-ratio vertical structures of amorphous silicon have been realized using hydrogen-assisted low-density plasma reactive ion etching. Amorphous silicon layers with the thicknesses ranging from 0.5 to 10 μm were deposited using radio frequency plasma enhanced chemical vapor deposition technique. Standard photolithography and nanosphere colloidal lithography were employed to realize ultra-small features of the amorphous silicon. The performance of the patterned amorphous silicon structures as a lithium-ion battery electrode was investigated using galvanostatic charge-discharge tests. The patterned structures showed a superior Li-ion battery performance compared to planar amorphous silicon. Such structures are suitable for high current Li-ion battery applications such as electric vehicles

  1. Highly featured amorphous silicon nanorod arrays for high-performance lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Soleimani-Amiri, Samaneh; Safiabadi Tali, Seied Ali; Azimi, Soheil; Sanaee, Zeinab; Mohajerzadeh, Shamsoddin, E-mail: mohajer@ut.ac.ir [Thin Film and Nanoelectronics Lab, Nanoelectronics Center of Excellence, School of Electrical and Computer Engineering, University of Tehran, Tehran 143957131 (Iran, Islamic Republic of)

    2014-11-10

    High aspect-ratio vertical structures of amorphous silicon have been realized using hydrogen-assisted low-density plasma reactive ion etching. Amorphous silicon layers with the thicknesses ranging from 0.5 to 10 μm were deposited using radio frequency plasma enhanced chemical vapor deposition technique. Standard photolithography and nanosphere colloidal lithography were employed to realize ultra-small features of the amorphous silicon. The performance of the patterned amorphous silicon structures as a lithium-ion battery electrode was investigated using galvanostatic charge-discharge tests. The patterned structures showed a superior Li-ion battery performance compared to planar amorphous silicon. Such structures are suitable for high current Li-ion battery applications such as electric vehicles.

  2. High breakdown-strength composites from liquid silicone rubbers

    DEFF Research Database (Denmark)

    Vudayagiri, Sindhu; Zakaria, Shamsul Bin; Yu, Liyun

    2014-01-01

    In this paper we investigate the performance of liquid silicone rubbers (LSRs) as dielectric elastomer transducers. Commonly used silicones in this application include room-temperature vulcanisable (RTV) silicone elastomers and composites thereof. Pure LSRs and their composites with commercially...

  3. 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.

  4. A high-temperature silicon-on-insulator stress sensor

    International Nuclear Information System (INIS)

    Wang Zheyao; Tian Kuo; Zhou Youzheng; Pan Liyang; Liu Litian; Hu Chaohong

    2008-01-01

    A piezoresistive stress sensor is developed using silicon-on-insulator (SOI) wafers and calibrated for stress measurement for high-temperature applications. The stress sensor consists of 'silicon-island-like' piezoresistor rosettes that are etched on the SOI layer. This eliminates leakage current and enables excellent electrical insulation at high temperature. To compensate for the measurement errors caused by the misalignment of the piezoresistor rosettes with respect to the crystallographic axes, an anisotropic micromachining technique, tetramethylammonium hydroxide etching, is employed to alleviate the misalignment issue. To realize temperature-compensated stress measurement, a planar diode is fabricated as a temperature sensor to decouple the temperature information from the piezoresistors, which are sensitive to both stress and temperature. Design, fabrication and calibration of the piezoresistors are given. SOI-related characteristics such as piezoresistive coefficients and temperature coefficients as well as the influence of the buried oxide layer are discussed in detail

  5. 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.

  6. Burnout in premedical undergraduate students.

    Science.gov (United States)

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

    2012-01-01

    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 in medical training, specifically, during undergraduate studies. Here, the authors surveyed undergraduates at UC San Diego (UCSD) to assess the relationship of burnout to premedical status while controlling for depression severity. Undergraduate students at UCSD were invited to participate in a web-based survey, consisting of demographic questions; the Maslach Burnout Inventory Student Survey (MBI-SS), which gauged the three dimensions of burnout; and the nine-item Patient Health Questionnaire (PHQ-9), to assess depression severity. A total of 618 premedical students and 1,441 non-premedical students completed the questionnaire. Premedical students had greater depression severity and emotional exhaustion than non-premedical students, but they also exhibited a greater sense of personal efficacy. The burnout differences were persistent even after adjusting for depression. Also, premedical women and Hispanic students had especially high levels of burnout, although differences between groups became nonsignificant after accounting for depression. Despite the limitations of using a burnout questionnaire not specifically normed for undergraduates, the unique ethnic characteristics of the sample, and the uncertain response rate, the findings highlight the importance of recognizing the unique strains and mental health disturbances that may be more common among premedical students than non-premedical students. Results also underscore the close relationship between depression and burnout, and point the way for subsequent longitudinal, multi-institutional studies that could help identify opportunities for prevention and intervention.

  7. Silicone rubber curing by high intensity infrared radiation

    International Nuclear Information System (INIS)

    Huang, T.; Tsai, J.; Cherng, C.; Chen, J.

    1994-01-01

    A high-intensity (12 kW) and compact (80 cm) infrared heating oven for fast curing (12 seconds) of tube-like silicone rubber curing studies is reported. Quality inspection by DSC and DMA and results from pilot-scale curing oven all suggest that infrared heating provides a better way of vulcanization regarding to curing time, quality, cost, and spacing over conventional hot air heating. copyright 1995 American Institute of Physics

  8. [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.

  9. Burnout and Doctors: Prevalence, Prevention and Intervention

    Science.gov (United States)

    Kumar, Shailesh

    2016-01-01

    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. PMID:27417625

  10. 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.

  11. High-efficiency concentrator silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, R.A.; Cuevas, A.; King, R.R.; Swanson, R.M. (Stanford Univ., CA (USA). Solid-State Electronics Lab.)

    1990-11-01

    This report presents results from extensive process development in high-efficiency Si solar cells. An advanced design for a 1.56-cm{sup 2} cell with front grids achieved 26% efficiency at 90 suns. This is especially significant since this cell does not require a prismatic cover glass. New designs for simplified backside-contact solar cells were advanced from a status of near-nonfunctionality to demonstrated 21--22% for one-sun cells in sizes up to 37.5 cm{sup 2}. An efficiency of 26% was achieved for similar 0.64-cm{sup 2} concentrator cells at 150 suns. More fundamental work on dopant-diffused regions is also presented here. The recombination vs. various process and physical parameters was studied in detail for boron and phosphorous diffusions. Emitter-design studies based solidly upon these new data indicate the performance vs design parameters for a variety of the cases of most interest to solar cell designers. Extractions of p-type bandgap narrowing and the surface recombination for p- and n-type regions from these studies have a generality that extends beyond solar cells into basic device modeling. 68 refs., 50 figs.

  12. Mesoporous Silicon-Based Anodes for High Capacity, High Performance Li-ion Batteries, Phase I

    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...

  13. 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.

  14. 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.

  15. Nurse Burnout and Patient Satisfaction

    Science.gov (United States)

    Vahey, Doris C.; Aiken, Linda H.; Sloane, Douglas M.; Clarke, Sean P.; Vargas, Delfino

    2010-01-01

    Background Amid a national nurse shortage, there is growing concern that high levels of nurse burnout could adversely affect patient outcomes. Objectives This study examines the effect of the nurse work environment on nurse burnout, and the effects of the nurse work environment and nurse burnout on patients' satisfaction with their nursing care. Research Design/Subjects We conducted cross-sectional surveys of nurses (N = 820) and patients (N = 621) from 40 units in 20 urban hospitals across the United States. Measures Nurse surveys included measures of nurses' practice environments derived from the revised Nursing Work Index (NWI-R) and nurse outcomes measured by the Maslach Burnout Inventory (MBI) and intentions to leave. Patients were interviewed about their satisfaction with nursing care using the La Monica-Oberst Patient Satisfaction Scale (LOPSS). Results Patients cared for on units that nurses characterized as having adequate staff, good administrative support for nursing care, and good relations between doctors and nurses were more than twice likely as other patients to report high satisfaction with their care, and their nurses reported significantly lower burnout. The overall level of nurse burnout on hospital units also affected patient satisfaction. Conclusions Improvements in nurses' work environments in hospitals have the potential to simultaneously reduce nurses' high levels of job burnout and risk of turnover and increase patients' satisfaction with their care. PMID:14734943

  16. Reducing teacher stress and burnout in high-risk secondary schools in South Africa using transactional analysis

    Directory of Open Access Journals (Sweden)

    Sharon Mary Johnson

    2015-01-01

    Full Text Available One of a number of articles arising from PhD research, this paper focuses on the results of applying transactional analysis as one of three approaches to reducing stress and burnout for teachers in high-risk secondary schools in the gangland areas of the Cape Flats, Western Cape, South Africa. The other approaches were Trauma Release Exercises (TRE and Transpersonal Psychology (TP, and related articles on these and on the quantitative statistical analysis elements of this research are being disseminated elsewhere. A total of 43 teachers in three different schools took part in one intervention held weekly over 10 weeks for one and a half hours (15 hours in total at their school as part of staff development, with a control group of 20 teachers at a fourth school. Qualitative TA intervention questionnaire coding analysis and focus group post-intervention thematic analysis of the mixed-methods study are presented. Coding analysis focused on the intra- and inter-individual tools that impacted teachers, and it was found that TA generated self-awareness, self-help tools and a strong group connection. Thematic analysis gave insights into the physical, emotional and cognitive responses to stress and burnout interventions on the individual, interpersonal and organisational levels and revealed new perspectives on classroom competency, with teachers taking more responsibility for discipline in the classroom. The study gave insights into the well-being and coping of educators who survive in these challenging contexts, and it is proposed that TRE, TP and TA approaches can be incorporated, and possibly combined, into integrative and eclectic ways of dealing with complex psychological challenges of stress and burnout reduction in traumatic environments.

  17. 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. Copyright © 2014 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

  18. 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...

  19. 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}.

  20. 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.

  1. Diamond and silicon pixel detectors in high radiation environments

    International Nuclear Information System (INIS)

    Tsung, Jieh-Wen

    2012-10-01

    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 16 particles per cm 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 15 particles per cm 2 .

  2. High Temperature Corrosion of Silicon Carbide and Silicon Nitride in Water Vapor

    Science.gov (United States)

    Opila, E. J.; Robinson, Raymond C.; Cuy, Michael D.; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    Silicon carbide (SiC) and silicon nitride (Si3N4) are proposed for applications in high temperature combustion environments containing water vapor. Both SiC and Si3N4 react with water vapor to form a silica (SiO2) scale. It is therefore important to understand the durability of SiC, Si3N4 and SiO2 in water vapor. Thermogravimetric analyses, furnace exposures and burner rig results were obtained for these materials in water vapor at temperatures between 1100 and 1450 C and water vapor partial pressures ranging from 0.1 to 3.1 atm. First, the oxidation of SiC and Si3N4 in water vapor is considered. The parabolic kinetic rate law, rate dependence on water vapor partial pressure, and oxidation mechanism are discussed. Second, the volatilization of silica to form Si(OH)4(g) is examined. Mass spectrometric results, the linear kinetic rate law and a volatilization model based on diffusion through a gas boundary layer are discussed. Finally, the combined oxidation and volatilization reactions, which occur when SiC or Si3N4 are exposed in a water vapor-containing environment, are presented. Both experimental evidence and a model for the paralinear kinetic rate law are shown for these simultaneous oxidation and volatilization reactions.

  3. High-rate silicon nitride deposition for photovoltaics : from fundamentals to industrial application

    NARCIS (Netherlands)

    Kessels, W.M.M.; Oever, van den P.J.; Bosch, R.C.M.; Bijker, M.D.; Evers, M.F.J.; Schram, D.C.; Sanden, van de M.C.M.

    2005-01-01

    The development of a novel plasma technique for high rate (> 1 nm/s) silicon nitride deposition for multifunctional antireflection coatings on crystalline silicon solar cells is described. The research has involved the analysis of the structural and optical properties of the silicon nitride films as

  4. High-rate silicon nitride deposition for photovoltaics : from fundamentals to industrial application

    NARCIS (Netherlands)

    Kessels, W.M.M.; Oever, van den P.J.; Bosch, R.C.M.; Bijker, M.D.; Evers, M.F.J.; Schram, D.C.; Sanden, van de M.C.M.

    2004-01-01

    The development of a novel plasma technique for high rate (> 1 nm/s) silicon nitride deposition for multifunctional antireflection coatings on crystalline silicon solar cells is described. The research has involved the analysis of the structural and optical properties of the silicon nitride films as

  5. Maslach Burnout Inventory and a Self-Defined, Single-Item Burnout Measure Produce Different Clinician and Staff Burnout Estimates.

    Science.gov (United States)

    Knox, Margae; Willard-Grace, Rachel; Huang, Beatrice; Grumbach, Kevin

    2018-06-04

    Clinicians and healthcare staff report high levels of burnout. Two common burnout assessments are the Maslach Burnout Inventory (MBI) and a single-item, self-defined burnout measure. Relatively little is known about how the measures compare. To identify the sensitivity, specificity, and concurrent validity of the self-defined burnout measure compared to the more established MBI measure. Cross-sectional survey (November 2016-January 2017). Four hundred forty-four primary care clinicians and 606 staff from three San Francisco Aarea healthcare systems. The MBI measure, calculated from a high score on either the emotional exhaustion or cynicism subscale, and a single-item measure of self-defined burnout. Concurrent validity was assessed using a validated, 7-item team culture scale as reported by Willard-Grace et al. (J Am Board Fam Med 27(2):229-38, 2014) and a standard question about workplace atmosphere as reported by Rassolian et al. (JAMA Intern Med 177(7):1036-8, 2017) and Linzer et al. (Ann Intern Med 151(1):28-36, 2009). Similar to other nationally representative burnout estimates, 52% of clinicians (95% CI: 47-57%) and 46% of staff (95% CI: 42-50%) reported high MBI emotional exhaustion or high MBI cynicism. In contrast, 29% of clinicians (95% CI: 25-33%) and 31% of staff (95% CI: 28-35%) reported "definitely burning out" or more severe symptoms on the self-defined burnout measure. The self-defined measure's sensitivity to correctly identify MBI-assessed burnout was 50.4% for clinicians and 58.6% for staff; specificity was 94.7% for clinicians and 92.3% for staff. Area under the receiver operator curve was 0.82 for clinicians and 0.81 for staff. Team culture and atmosphere were significantly associated with both self-defined burnout and the MBI, confirming concurrent validity. Point estimates of burnout notably differ between the self-defined and MBI measures. Compared to the MBI, the self-defined burnout measure misses half of high-burnout clinicians and more

  6. 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.

  7. BURNOUT SYNDROM AMONG PUBLIC AMBULANCE STAFF.

    Science.gov (United States)

    Iorga, Magdalena; Dascalu, Neonila; Soponaru, Camelia; Ioan, Beatrice

    2015-01-01

    Healthcare professionals are frequently confronted with urgent situations and a high-risk human intervention. They are usually exposed to what is called burnout syndrome. To identify the effects of burnout syndrome on the professional conduct and attitudes of doctors and nurses who work in the Romanian public ambulance service. Secondary, the causal relationships between burnout and various socio-demographic variables were analyzed. The 20-item Toronto Alexithymia Scale (TAS- 20), Maslach Burnout Inventory and Job Satisfaction Questionnaire were administered to 122 ambulance doctors, nurses and drivers (62 females and 60 males). The degree of job satisfaction is the most important indicator of burnout syndrome. Significant differences were found between low and high alexithymic subjects. Women are more susceptible to experience higher levels of burnout than men. The level of burnout is influenced by the combined effect of job satisfaction and alexithymia. Burnout syndrome is a common problem among people working in the emergency medical system. The causes of job-related burnout have to be identified in order to apply an appropriate level of burnout intervention program and to increase the efficiency of coping strategies.

  8. 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.

  9. 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.

  10. Burnout Syndrome

    OpenAIRE

    Panova, Gordana; Panov, Nenad; Stojanov, H; Sumanov, Gorgi; Panova, Blagica; Stojanovski, Angel; Nikolovska, Lence; Jovevska, Svetlana; Trajanovski, D; Asanova, D

    2013-01-01

    Introduction: Increasing work responsibilities, allocation of duties, loss of energy and motivation in everyday activities, emotional exhaustion, lack of time for themselves, insuffi cient time for rest and recreation, dissatisfaction in private life. All these symptoms can be cause of Burnout Syndrome. Aim: To see the importance of this syndrome, the consequences of job dissatisfaction, the environment, family and expression in drastic chan...

  11. High temperature corrosion of silicon carbide and silicon nitride in the presence of chloride compound

    International Nuclear Information System (INIS)

    McNallan, M.

    1993-01-01

    Silicon carbide and silicon nitride are resistant to oxidation because a protective silicon dioxide films on their surfaces in most oxidizing environments. Chloride compounds can attack the surface in two ways: 1) chlorine can attack the silicon directly to form a volatile silicon chloride compound or 2) alkali compounds combined with the chlorine can be transported to the surface where they flux the silica layer by forming stable alkali silicates. Alkali halides have enough vapor pressure that a sufficient quantity of alkali species to cause accelerated corrosion can be transported to the ceramic surface without the formation of a chloride deposit. When silicon carbide is attacked simultaneously by chlorine and oxygen, the corrosion products include both volatile and condensed spices. Silicon nitride is much more resistance to this type of attack than silicon carbide. Silicon based ceramics are exposed to oxidizing gases in the presence of alkali chloride vapors, the rate of corrosion is controlled primarily by the driving force for the formation of alkali silicate, which can be quantified as the activity of the alkali oxide in equilibrium with the corrosive gas mixture. In a gas mixture containing a fixed partial pressure of KCl, the rate of corrosion is accelerated by increasing the concentration of water vapor and inhibited by increasing the concentration of HCl. Similar results have been obtained for mixtures containing other alkalis and halogens. (Orig./A.B.)

  12. Burnout in medical students: a systematic review.

    Science.gov (United States)

    Ishak, Waguih; Nikravesh, Rose; Lederer, Sara; Perry, Robert; Ogunyemi, Dotun; Bernstein, Carol

    2013-08-01

    Burnout is a state of mental and physical exhaustion related to work or care-giving activities. Distress during medical school can lead to burnout, with significant consequences, particularly if burnout continues into residency and beyond. The authors reviewed literature pertaining to medical student burnout, its prevalence, and its relationship to personal, environmental, demographic and psychiatric factors. We ultimately offer some suggestions to address and potentially ameliorate the current dilemma posed by burnout during medical education. A literature review was conducted using a PubMed/Medline, and PsycInfo search from 1974 to 2011 using the keywords: 'burnout', 'stress', 'well-being', 'self-care', 'psychiatry' and 'medical students'. Three authors agreed independently on the studies to be included in this review. The literature reveals that burnout is prevalent during medical school, with major US multi-institutional studies estimating that at least half of all medical students may be affected by burnout during their medical education. Studies show that burnout may persist beyond medical school, and is, at times, associated with psychiatric disorders and suicidal ideation. A variety of personal and professional characteristics correlate well with burnout. Potential interventions include school-based and individual-based activities to increase overall student well-being. Burnout is a prominent force challenging medical students' well-being, with concerning implications for the continuation of burnout into residency and beyond. To address this highly prevalent condition, educators must first develop greater awareness and understanding of burnout, as well as of the factors that lead to its development. Interventions focusing on generating wellness during medical training are highly recommended. © 2013 John Wiley & Sons Ltd.

  13. 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.

  14. Commitment to Classroom Model Philosophy and Burnout Symptoms among High Fidelity Teachers Implementing Preschool Programs for Children with Autism Spectrum Disorders

    Science.gov (United States)

    Coman, Drew; Alessandri, Michael; Gutierrez, Anibal; Novotny, Stephanie; Boyd, Brian; Hume, Kara; Sperry, Laurie; Odom, Samuel

    2013-01-01

    Teacher commitment to classroom model philosophy and burnout were explored in a sample of 53 teachers implementing three preschool models at high levels of fidelity for students with autism: Treatment and Education of Autistic and Related Communication Handicapped Children (TEACCH); Learning Experiences and Alternative Program for Preschoolers and…

  15. Passivating electron contact based on highly crystalline nanostructured silicon oxide layers for silicon solar cells

    Czech Academy of Sciences Publication Activity Database

    Stuckelberger, J.; Nogay, G.; Wyss, P.; Jeangros, Q.; Allebe, Ch.; Debrot, F.; Niquille, X.; Ledinský, Martin; Fejfar, Antonín; Despeisse, M.; Haug, F.J.; Löper, P.; Ballif, C.

    2016-01-01

    Roč. 158, Dec (2016), s. 2-10 ISSN 0927-0248 R&D Projects: GA MŠk LM2015087 Institutional support: RVO:68378271 Keywords : surface passivation * passivating contact * nanostructure * silicon oxide * nanocrystalline * microcrystalline * poly-silicon * crystallization * Raman * transmission line measurement Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.784, year: 2016

  16. Development of Silicon Detectors for the High Luminosity LHC

    International Nuclear Information System (INIS)

    Eichhorn, Thomas Valentin

    2015-07-01

    The Large Hadron Collider (LHC) at CERN will be upgraded to a High Luminosity LHC in the year 2022, increasing the instantaneous luminosity by a factor of five. This will have major impacts on the experiments at the LHC, such as the Compact Muon Solenoid (CMS) experiment, and especially for their inner silicon tracking systems. Among other things, the silicon sensors used therein will be exposed to unprecedented levels of radiation damage, necessitating a replacement of the entire tracking detector. In order to maintain the excellent current performance, a new tracking detector has to be equipped with sensors of increased radiation hardness and higher granularity. The CMS experiment is undertaking an extensive R and D campaign in the search for the future silicon sensor technology baseline to be used in this upgrade. This thesis presents two methods suitable for use in this search: finite element TCAD simulations and test beam measurements. The simulations are focussed on the interstrip capacitance between sensor strips and are compared to measurements before and after the inclusion of radiation damage effects. A geometrical representation of the strip sensors used in the campaign has been found, establishing the predictive power of simulations. The test beam measurements make use of the high-precision pixel telescopes available at the DESY-II test beam facility. The performance of these telescopes has been assessed and their achievable pointing resolution has been found to be below 2 μm. Thin, epitaxial silicon is a candidate material for usage in radiation hard sensors for the future CMS tracking detector. Sample strip sensors of this material have been irradiated to fluences of up to 1.3 x 10 16 n eq /cm 2 with 800 MeV or 23 GeV protons. Test beam measurements with 5 GeV electrons have been performed to investigate the radiation hardness of epitaxial sensors using the pixel beam telescopes. The epitaxial device under test (DUT) has been integrated into the

  17. High performance hybrid silicon micropillar solar cell based on light trapping characteristics of Cu nanoparticles

    Directory of Open Access Journals (Sweden)

    Yulong Zhang

    2018-05-01

    Full Text Available High performance silicon combined structure (micropillar with Cu nanoparticles solar cell has been synthesized from N-type silicon substrates based on the micropillar array. The combined structure solar cell exhibited higher short circuit current rather than the silicon miropillar solar cell, which the parameters of micropillar array are the same. Due to the Cu nanoparticles were decorated on the surface of silicon micropillar array, the photovoltaic properties of cells have been improved. In addition, the optimal efficiency of 11.5% was measured for the combined structure solar cell, which is better than the silicon micropillar cell.

  18. Broadband infrared photoluminescence in silicon nanowires with high density stacking faults.

    Science.gov (United States)

    Li, Yang; Liu, Zhihong; Lu, Xiaoxiang; Su, Zhihua; Wang, Yanan; Liu, Rui; Wang, Dunwei; Jian, Jie; Lee, Joon Hwan; Wang, Haiyan; Yu, Qingkai; Bao, Jiming

    2015-02-07

    Making silicon an efficient light-emitting material is an important goal of silicon photonics. Here we report the observation of broadband sub-bandgap photoluminescence in silicon nanowires with a high density of stacking faults. The photoluminescence becomes stronger and exhibits a blue shift under higher laser powers. The super-linear dependence on excitation intensity indicates a strong competition between radiative and defect-related non-radiative channels, and the spectral blue shift is ascribed to the band filling effect in the heterostructures of wurtzite silicon and cubic silicon created by stacking faults.

  19. High performance hybrid silicon micropillar solar cell based on light trapping characteristics of Cu nanoparticles

    Science.gov (United States)

    Zhang, Yulong; Fan, Zhiqiang; Zhang, Weijia; Ma, Qiang; Jiang, Zhaoyi; Ma, Denghao

    2018-05-01

    High performance silicon combined structure (micropillar with Cu nanoparticles) solar cell has been synthesized from N-type silicon substrates based on the micropillar array. The combined structure solar cell exhibited higher short circuit current rather than the silicon miropillar solar cell, which the parameters of micropillar array are the same. Due to the Cu nanoparticles were decorated on the surface of silicon micropillar array, the photovoltaic properties of cells have been improved. In addition, the optimal efficiency of 11.5% was measured for the combined structure solar cell, which is better than the silicon micropillar cell.

  20. The development of high resolution silicon x-ray microcalorimeters

    Science.gov (United States)

    Porter, F. S.; Kelley, R. L.; Kilbourne, C. A.

    2005-12-01

    Recently we have produced x-ray microcalorimeters with resolving powers approaching 2000 at 5.9 keV using a spare XRS microcalorimeter array. We attached 400 um square, 8 um thick HgTe absorbers using a variety of attachment methods to an XRS array and ran the detector array at temperatures between 40 and 60 mK. The best results were for absorbers attached using the standard XRS absorber-pixel thermal isolation scheme utilizing SU8 polymer tubes. In this scenario we achieved a resolution of 3.2 eV FWHM at 5.9 keV. Substituting a silicon spacer for the SU8 tubes also yielded sub-4eV results. In contrast, absorbers attached directly to the thermistor produced significant position dependence and thus degraded resolution. Finally, we tested standard 640um-square XRS detectors at reduced bias power at 50mK and achieved a resolution of 3.7eV, a 50% improvement over the XRS flight instrument. Implanted silicon microcalorimeters are a mature flight-qualified technology that still has a substantial phase space for future development. We will discuss these new high resolution results, the various absorber attachment schemes, planned future improvements, and, finally, their relevance to future high resolution x-ray spectrometers including Constellation-X.

  1. Silicon nanowire based high brightness, pulsed relativistic electron source

    Directory of Open Access Journals (Sweden)

    Deep Sarkar

    2017-06-01

    Full Text Available We demonstrate that silicon nanowire arrays efficiently emit relativistic electron pulses under irradiation by a high-intensity, femtosecond, and near-infrared laser (∼1018 W/cm2, 25 fs, 800 nm. The nanowire array yields fluxes and charge per bunch that are 40 times higher than those emitted by an optically flat surface, in the energy range of 0.2–0.5 MeV. The flux and charge yields for the nanowires are observed to be directional in nature unlike that for planar silicon. Particle-in-cell simulations establish that such large emission is caused by the enhancement of the local electric fields around a nanowire, which consequently leads to an enhanced absorption of laser energy. We show that the high-intensity contrast (ratio of picosecond pedestal to femtosecond peak of the laser pulse (10−9 is crucial to this large yield. We extend the notion of surface local-field enhancement, normally invoked in low-order nonlinear optical processes like second harmonic generation, optical limiting, etc., to ultrahigh laser intensities. These electron pulses, expectedly femtosecond in duration, have potential application in imaging, material modification, ultrafast dynamics, terahertz generation, and fast ion sources.

  2. 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.

  3. 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.

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

    KAUST Repository

    Hussain, Muhammad Mustafa; Rojas, Jhonathan Prieto; Sevilla, Galo T.

    2013-01-01

    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.

  5. Denuded zone in Czochralski silicon wafer with high carbon content

    International Nuclear Information System (INIS)

    Chen Jiahe; Yang Deren; Ma Xiangyang; Que Duanlin

    2006-01-01

    The thermal stability of the denuded zone (DZ) created by high-low-high-temperature annealing in high carbon content (H[C]) and low carbon content (L[C]) Czochralski silicon (Cz-Si) has been investigated in a subsequent ramping and isothermal 1050 deg. C annealing. The tiny oxygen precipitates which might occur in the DZ were checked. It was found in the L[C] Cz-Si that the DZ shrank and the density of bulk micro-defects (BMDs) reduced with the increase of time spent at 1050 deg. C. Also, the DZs above 15 μm of thickness present in the H[C] Cz-Si wafers continuously and the density and total volume of BMDs first decreased then increased and finally decreased again during the treatments. Moreover, tiny oxygen precipitates were hardly generated inside the DZs, indicating that H[C] Cz-Si wafers could support the fabrication of integrated circuits

  6. Denuded zone in Czochralski silicon wafer with high carbon content

    Science.gov (United States)

    Chen, Jiahe; Yang, Deren; Ma, Xiangyang; Que, Duanlin

    2006-12-01

    The thermal stability of the denuded zone (DZ) created by high-low-high-temperature annealing in high carbon content (H[C]) and low carbon content (L[C]) Czochralski silicon (Cz-Si) has been investigated in a subsequent ramping and isothermal 1050 °C annealing. The tiny oxygen precipitates which might occur in the DZ were checked. It was found in the L[C] Cz-Si that the DZ shrank and the density of bulk micro-defects (BMDs) reduced with the increase of time spent at 1050 °C. Also, the DZs above 15 µm of thickness present in the H[C] Cz-Si wafers continuously and the density and total volume of BMDs first decreased then increased and finally decreased again during the treatments. Moreover, tiny oxygen precipitates were hardly generated inside the DZs, indicating that H[C] Cz-Si wafers could support the fabrication of integrated circuits.

  7. 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…

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

    Energy Technology Data Exchange (ETDEWEB)

    Otte, Adam Nepomuk, E-mail: otte@gatech.edu; Garcia, Distefano; Nguyen, Thanh; Purushotham, Dhruv

    2017-02-21

    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/mm{sup 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 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.

  9. Development of high-efficiency solar cells on silicon web

    Science.gov (United States)

    Meier, D. L.; Greggi, J.; Okeeffe, T. W.; Rai-Choudhury, P.

    1986-01-01

    Work was performed to improve web base material with a goal of obtaining solar cell efficiencies in excess of 18% (AM1). Efforts in this program are directed toward identifying carrier loss mechanisms in web silicon, eliminating or reducing these mechanisms, designing a high efficiency cell structure with the aid of numerical models, and fabricating high efficiency web solar cells. Fabrication techniques must preserve or enhance carrier lifetime in the bulk of the cell and minimize recombination of carriers at the external surfaces. Three completed cells were viewed by cross-sectional transmission electron microscopy (TEM) in order to investigate further the relation between structural defects and electrical performance of web cells. Consistent with past TEM examinations, the cell with the highest efficiency (15.0%) had no dislocations but did have 11 twin planes.

  10. 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...

  11. 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…

  12. Differential diagnostic of the burnout syndrome.

    Science.gov (United States)

    Korczak, Dieter; Huber, Beate; Kister, Christine

    2010-07-05

    There is no consistent definition of burnout. It is neither a defined diagnosis in ICD-10 nor in DSM-IV. Yet it is diagnosed by office-based doctors and clinicians. Mainly due to reimbursement reasons, diagnoses like depression are used instead of burnout diagnoses. Therefore burnout has a very high individual, social and economic impact. How is burnout diagnosed? Which criteria are relevant? How valid and reliable are the used tools?What kind of disorders in case of burnout are relevant for a differential diagnosis?What is the economic effect of a differential diagnosis for burnout?Are there any negative effects of persons with burnout on patients or clients?Can stigmatization of burnout-patients or -clients be observed? Based on a systematic literature research in 36 databases, studies in English or German language, published since 2004, concerning medical and differential diagnoses, economic impact and ethical aspects of burnout, are included and evaluated. 852 studies are identified. After considering the inclusion and exclusion criteria and after reviewing the full texts, 25 medical and one ethical study are included. No economic study met the criteria. The key result of this report is that so far no standardized, general and international valid procedure exists to obtain a burnout diagnosis. At present, it is up to the physician's discretion to diagnose burnout. The overall problem is to measure a phenomenon that is not exactly defined. The current available burnout measurements capture a three dimensional burnout construct. But the cutoff points do not conform to the standards of scientifically valid test construction. It is important to distinguish burnout from depression, alexithymia, feeling unwell and the concept of prolonged exhaustion. An intermittent relation of the constructs is possible. Furthermore, burnout goes along with various ailments like sleep disturbance. Through a derogation of work performance it can have also negative effects on

  13. Differential diagnostic of the burnout syndrome

    Directory of Open Access Journals (Sweden)

    Kister, Christine

    2010-01-01

    Full Text Available Introduction: There is no consistent definition of burnout. It is neither a defined diagnosis in ICD-10 nor in DSM-IV. Yet it is diagnosed by office-based doctors and clinicians. Mainly due to reimbursement reasons, diagnoses like depression are used instead of burnout diagnoses. Therefore burnout has a very high individual, social and economic impact. Objectives: How is burnout diagnosed? Which criteria are relevant? How valid and reliable are the used tools? What kind of disorders in case of burnout are relevant for a differential diagnosis? What is the economic effect of a differential diagnosis for burnout? Are there any negative effects of persons with burnout on patients or clients? Can stigmatization of burnout-patients or -clients be observed? Methods: Based on a systematic literature research in 36 databases, studies in English or German language, published since 2004, concerning medical and differential diagnoses, economic impact and ethical aspects of burnout, are included and evaluated. Results: 852 studies are identified. After considering the inclusion and exclusion criteria and after reviewing the full texts, 25 medical and one ethical study are included. No economic study met the criteria.The key result of this report is that so far no standardized, general and international valid procedure exists to obtain a burnout diagnosis. At present, it is up to the physician’s discretion to diagnose burnout. The overall problem is to measure a phenomenon that is not exactly defined. The current available burnout measurements capture a three dimensional burnout construct. But the cutoff points do not conform to the standards of scientifically valid test construction. It is important to distinguish burnout from depression, alexithymia, feeling unwell and the concept of prolonged exhaustion. An intermittent relation of the constructs is possible. Furthermore, burnout goes along with various ailments like sleep disturbance. Through a

  14. Thermoelectric Properties of High-Doped Silicon from Room Temperature to 900 K

    Science.gov (United States)

    Stranz, A.; Kähler, J.; Waag, A.; Peiner, E.

    2013-07-01

    Silicon is investigated as a low-cost, Earth-abundant thermoelectric material for high-temperature applications up to 900 K. For the calculation of module design the Seebeck coefficient and the electrical as well as thermal properties of silicon in the high-temperature range are of great importance. In this study, we evaluate the thermoelectric properties of low-, medium-, and high-doped silicon from room temperature to 900 K. In so doing, the Seebeck coefficient, the electrical and thermal conductivities, as well as the resulting figure of merit ZT of silicon are determined.

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

    Science.gov (United States)

    Lee, Yii-Ching; Huang, Shian-Chang; Huang, Chih-Hsuan; Wu, Hsin-Hung

    2016-01-01

    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. © The Author(s) 2016.

  16. 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.

  17. 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…

  18. 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

  19. 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.

  20. Passion and Burnout in College Students

    Science.gov (United States)

    Saville, Bryan K.; Bureau, Alex; Eckenrode, Claire; Maley, Michelle

    2018-01-01

    Previous research on passion and burnout has shown that teachers, including college faculty, who show high levels of harmonious passion toward their work experience lower burnout than teachers who have high levels of obsessive passion. In the present study, we extended this line of research to college students. We found that students who were…

  1. 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.

  2. 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 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.

  3. 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.

  4. 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.

  5. Porous silicon phantoms for high-resolution scintillation imaging

    Energy Technology Data Exchange (ETDEWEB)

    Di Francia, G. [Portici Research Centre, ENEA, Via Vecchio Macello, 80055 Portici, Naples (Italy); Scafe, R. [Casaccia Research Centre, ENEA, 00060 S.Maria di Galeria, Rome (Italy)]. E-mail: scafe@casaccia.enea.it; De Vincentis, G. [Department of Radiological Sciences, University of Rome ' La Sapienza' , V.le Regina Elena, 324, 00161 Rome (Italy); La Ferrara, V. [Portici Research Centre, ENEA, Via Vecchio Macello, 80055 Portici, Naples (Italy); Iurlaro, G. [Casaccia Research Centre, ENEA, 00060 S.Maria di Galeria, Rome (Italy); Nasti, I. [Portici Research Centre, ENEA, Via Vecchio Macello, 80055 Portici, Naples (Italy); Montani, L. [Casaccia Research Centre, ENEA, 00060 S.Maria di Galeria, Rome (Italy); Pellegrini, R. [Department of Experimental Medicine, University of Rome ' La Sapienza' , V.le Regina Elena, 324, 00161 Rome (Italy); Betti, M. [Department of Experimental Medicine, University of Rome ' La Sapienza' , V.le Regina Elena, 324, 00161 Rome (Italy); Martucciello, N. [Portici Research Centre, ENEA, Via Vecchio Macello, 80055 Portici, Naples (Italy); Pani, R. [Department of Experimental Medicine, University of Rome ' La Sapienza' , V.le Regina Elena, 324, 00161 Rome (Italy)

    2006-12-20

    High resolution radionuclide imaging requires phantoms with precise geometries and known activities using either Anger cameras equipped with pinhole collimators or dedicated small animal devices. Porous silicon samples, having areas of different shape and size, can be made and loaded with a radioactive material, obtaining: (a) precise radio-emitting figures corresponding to the porous areas geometry (b) a radioactivity of each figure depending on the pore's specifications, and (c) the same emission energy to be used in true exams. To this aim a sample with porous circular areas has been made and loaded with a {sup 99m}TcO{sub 4} {sup -} solution. Imaging has been obtained using both general purpose and pinhole collimators. This first sample shows some defects that are analyzed and discussed.

  6. Thermally stimulated current method applied to highly irradiated silicon diodes

    CERN Document Server

    Pintilie, I; Pintilie, I; Moll, Michael; Fretwurst, E; Lindström, G

    2002-01-01

    We propose an improved method for the analysis of Thermally Stimulated Currents (TSC) measured on highly irradiated silicon diodes. The proposed TSC formula for the evaluation of a set of TSC spectra obtained with different reverse biases leads not only to the concentration of electron and hole traps visible in the spectra but also gives an estimation for the concentration of defects which not give rise to a peak in the 30-220 K TSC temperature range (very shallow or very deep levels). The method is applied to a diode irradiated with a neutron fluence of phi sub n =1.82x10 sup 1 sup 3 n/cm sup 2.

  7. High yield silicon carbide pre-ceramic polymers

    International Nuclear Information System (INIS)

    Baney, R.H.

    1982-01-01

    Polysilanes which are substituted with (CH 3 ) 3 SiO-groups are useful for the preparation in high yields of fine grained silicon carbide ceramic materials. They consist of 0 to 60 mole % (CH 3 ) 2 Si units and 100 to 40 mole % CH 3 Si units, all Si valences not satisfied by CH 3 groups or Si atoms being directed to groups (CH 3 ) 3 SiO-, which siloxane groups amount to 23 to 61 weight % of the polysilane. They are prepared by reaction of the corresponding chloro- or bromo-methyl polysilanes with at least the stoichiometric amounts of (CH 3 ) 3 SiOSi(CH 3 ) 3 and water in the presence of a strong acid. (author)

  8. Family medicine residency training and burnout: a qualitative study

    Directory of Open Access Journals (Sweden)

    Kimberly Rutherford

    2014-12-01

    Conclusions: The high level of burnout in family medicine residents in BC is a multifactorial and complex phenomenon. Training programs and faculty should be aware of burnout risk factors and strive to implement changes to reduce burnout, including allowing residents increased control over scheduling, access to counseling services and training for resident mentors.

  9. 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.

  10. Fabrication and Characterisation of Silicon Waveguides for High-Speed Optical Signal Processing

    DEFF Research Database (Denmark)

    Jensen, Asger Sellerup

    This Ph.D. thesis treats various aspects of silicon photonics. From the limitations of silicon as a linear and nonlinear waveguide medium to its synergy with other waveguide materials. Various methods for reducing sidewall roughness and line edge roughness of silicon waveguides are attempted...... was too high for any practical applications. It is speculated that the attempt at creating a material with low density of dangling bonds was unsuccessful. Nevertheless, linear losses of 2.4dB/cm at 1550nm wavelength in the silicon waveguides remained sufficiently low that high speed nonlinear optical...

  11. The Associations Between Long Working Hours, Physical Inactivity, and Burnout.

    Science.gov (United States)

    Hu, Nien-Chih; Chen, Jong-Dar; Cheng, Tsun-Jen

    2016-05-01

    To examine the correlations between long working hours, physical activity, and burnout. A cross-sectional survey was administered to 1560 full-time employees, who underwent periodic health examinations in the year 2013. The subjects were divided into upper, middle, and lower tertiles according to the Copenhagen Burnout Inventory (CBI) score. The comparison of the high- and low-burnout groups revealed that long working hours were significantly correlated with burnout in a dose-dependent manner. Long working hours were more significantly associated with burnout among individuals younger than 50 years, females, and physically inactive employees. Long working hours are correlated with burnout when working over 40 hours per week and is even stronger when working over 60 hours per week. Limiting working hours to 40 weekly may be beneficial for the prevention of burnout. Physical activity helps reduce the risk of burnout.

  12. Burnout in perioperative context

    OpenAIRE

    Galvão, Ana Maria; Gonçalves, Ana Rita Veloso; Certo, Ana

    2014-01-01

    Companies in a global context are going through moments of great development of information and technologies. In these environments Burnout is highly prevalent, this syndrome is considered as one of physical and emotional stress that leads to a lack of motivation to work, leading to a progressive sense of inadequacy and failure. Objectives: What level of stress Perioperative nurses for nurses in the Region of Tras-os-Montes and Alto Douro. Methods: Non-experimental study,...

  13. Structural and optical properties of silicon-carbide nanowires produced by the high-temperature carbonization of silicon nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Pavlikov, A. V., E-mail: pavlikov@physics.msu.ru [Moscow State University, Faculty of Physics (Russian Federation); Latukhina, N. V.; Chepurnov, V. I. [Samara National Researh University (Russian Federation); Timoshenko, V. Yu. [Moscow State University, Faculty of Physics (Russian Federation)

    2017-03-15

    Silicon-carbide (SiC) nanowire structures 40–50 nm in diameter are produced by the high-temperature carbonization of porous silicon and silicon nanowires. The SiC nanowires are studied by scanning electron microscopy, X-ray diffraction analysis, Raman spectroscopy, and infrared reflectance spectroscopy. The X-ray structural and Raman data suggest that the cubic 3C-SiC polytype is dominant in the samples under study. The shape of the infrared reflectance spectrum in the region of the reststrahlen band 800–900 cm{sup –1} is indicative of the presence of free charge carriers. The possibility of using SiC nanowires in microelectronic, photonic, and gas-sensing devices is discussed.

  14. A 1024 pad silicon detector to solve tracking ambiguities in high multiplicity events

    International Nuclear Information System (INIS)

    Simone, S.; Catanesi, M.G.; Di Bari, D.; Didonna, V.; Elia, D.; Ghidini, B.; Lenti, V.; Manzari, V.; Nappi, E.

    1996-01-01

    Silicon detectors with two-dimensional pad readout have been designed and constructed for the WA97 experiment at CERN, in order to solve ambiguities for track reconstruction in a silicon microstrip telescope. A high density fanouts has been developed on a glass support to allow the electrical contacts between the detector and the front end electronics. Silicon pad detectors have been successfully operated both during the proton-Pb and Pb-Pb runs of the WA97 experiment. (orig.)

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

    KAUST Repository

    Sevilla, Galo T.; Almuslem, A. S.; Gumus, Abdurrahman; Hussain, Aftab M.; Hussain, Aftab M.; Cruz, Melvin; Hussain, Muhammad Mustafa

    2016-01-01

    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

  16. High-performance lithium battery anodes using silicon nanowires.

    Science.gov (United States)

    Chan, Candace K; Peng, Hailin; Liu, Gao; McIlwrath, Kevin; Zhang, Xiao Feng; Huggins, Robert A; Cui, Yi

    2008-01-01

    There is great interest in developing rechargeable lithium batteries with higher energy capacity and longer cycle life for applications in portable electronic devices, electric vehicles and implantable medical devices. Silicon is an attractive anode material for lithium batteries because it has a low discharge potential and the highest known theoretical charge capacity (4,200 mAh g(-1); ref. 2). Although this is more than ten times higher than existing graphite anodes and much larger than various nitride and oxide materials, silicon anodes have limited applications because silicon's volume changes by 400% upon insertion and extraction of lithium which results in pulverization and capacity fading. Here, we show that silicon nanowire battery electrodes circumvent these issues as they can accommodate large strain without pulverization, provide good electronic contact and conduction, and display short lithium insertion distances. We achieved the theoretical charge capacity for silicon anodes and maintained a discharge capacity close to 75% of this maximum, with little fading during cycling.

  17. A Highly Responsive Silicon Nanowire/Amplifier MOSFET Hybrid Biosensor.

    Science.gov (United States)

    Lee, Jieun; Jang, Jaeman; Choi, Bongsik; Yoon, Jinsu; Kim, Jee-Yeon; Choi, Yang-Kyu; Kim, Dong Myong; Kim, Dae Hwan; Choi, Sung-Jin

    2015-07-21

    This study demonstrates a hybrid biosensor comprised of a silicon nanowire (SiNW) integrated with an amplifier MOSFET to improve the current response of field-effect-transistor (FET)-based biosensors. The hybrid biosensor is fabricated using conventional CMOS technology, which has the potential advantage of high density and low noise performance. The biosensor shows a current response of 5.74 decades per pH for pH detection, which is 2.5 × 10(5) times larger than that of a single SiNW sensor. In addition, we demonstrate charged polymer detection using the biosensor, with a high current change of 4.5 × 10(5) with a 500 nM concentration of poly(allylamine hydrochloride). In addition, we demonstrate a wide dynamic range can be obtained by adjusting the liquid gate voltage. We expect that this biosensor will be advantageous and practical for biosensor applications which requires lower noise, high speed, and high density.

  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. The status of silicon ribbon growth technology for high-efficiency silicon solar cells

    Science.gov (United States)

    Ciszek, T. F.

    1985-01-01

    More than a dozen methods have been applied to the growth of silicon ribbons, beginning as early as 1963. The ribbon geometry has been particularly intriguing for photovoltaic applications, because it might provide large area, damage free, nearly continuous substrates without the material loss or cost of ingot wafering. In general, the efficiency of silicon ribbon solar cells has been lower than that of ingot cells. The status of some ribbon growth techniques that have achieved laboratory efficiencies greater than 13.5% are reviewed, i.e., edge-defined, film-fed growth (EFG), edge-supported pulling (ESP), ribbon against a drop (RAD), and dendritic web growth (web).

  20. Is caseload midwifery a healthy work-form? - A survey of burnout among midwives in Denmark

    DEFF Research Database (Denmark)

    Jepsen, Ingrid; Juul, Svend; Foureur, Maralyn

    2017-01-01

    Objective: To investigate the level of burnout among midwives working in caseloading practices compared to other models of midwifery care. Study design and setting: In this survey the Copenhagen Burnout Inventory was used to measure burnout among midwives working in a tertiary maternity unit...... Denmark. Main outcome measures: Mean burnout scores and the proportion of midwives with high burnout scores (a score >= 50). Results: The response rate was 82.0% as 50 out of 61 midwives answered the questionnaire. In caseload midwifery the burnout scores in personal, work-related and client......-related burnout were significantly lower when compared to ‘‘other models of care”. Among caseloading midwives, none had high scores of burnout in any of the measured domains. The proportions of high burnout scores among all of the participating midwives were 22% (95% CI: 12%–36%) in personal burnout, 20% (95% CI...

  1. Electrical characterization of high-pressure reactive sputtered ScOx films on silicon

    International Nuclear Information System (INIS)

    Castan, H.; Duenas, S.; Gomez, A.; Garcia, H.; Bailon, L.; Feijoo, P.C.; Toledano-Luque, M.; Prado, A. del; San Andres, E.; Lucia, M.L.

    2011-01-01

    Al/ScO x /SiN x /n-Si and Al/ScO x /SiO x /n-Si metal-insulator-semiconductor capacitors have been electrically characterized. Scandium oxide was grown by high-pressure sputtering on different substrates to study the dielectric/insulator interface quality. The substrates were silicon nitride and native silicon oxide. The use of a silicon nitride interfacial layer between the silicon substrate and the scandium oxide layer improves interface quality, as interfacial state density and defect density inside the insulator are decreased.

  2. 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.

  3. Silicon micromachining using a high-density plasma source

    International Nuclear Information System (INIS)

    McAuley, S.A.; Ashraf, H.; Atabo, L.; Chambers, A.; Hall, S.; Hopkins, J.; Nicholls, G.

    2001-01-01

    Dry etching of Si is critical in satisfying the demands of the micromachining industry. The micro-electro-mechanical systems (MEMS) community requires etches capable of high aspect ratios, vertical profiles, good feature size control and etch uniformity along with high throughput to satisfy production requirements. Surface technology systems' (STS's) high-density inductively coupled plasma (ICP) etch tool enables a wide range of applications to be realized whilst optimizing the above parameters. Components manufactured from Si using an STS ICP include accelerometers and gyroscopes for military, automotive and domestic applications. STS's advanced silicon etch (ASE TM ) has also allowed the first generation of MEMS-based optical switches and attenuators to reach the marketplace. In addition, a specialized application for fabricating the next generation photolithography exposure masks has been optimized for 200 mm diameter wafers, to depths of ∼750 μm. Where the profile is not critical, etch rates of greater than 8 μm min -1 have been realized to replace previous methods such as wet etching. This is also the case for printer applications. Specialized applications that require etching down to pyrex or oxide often result in the loss of feature size control at the interface; this is an industry wide problem. STS have developed a technique to address this. The rapid progression of the industry has led to development of the STS ICP etch tool, as well as the process. (author)

  4. Burnout among family and general practitioners

    Directory of Open Access Journals (Sweden)

    Ghaida M.J. Al-Shoraian

    2011-12-01

    Full Text Available Background: Job burnout is an important syndrome that can deplete the emotional health aspects of physicians. Its impacts are reflected both on the physicians and their patients through undermining the performance of physicians and degrading the quality of the administered medical care leading to dissatisfaction of the patients about the medical service. Objectives: This study is formulated to compare the prevalence of high burnout among family physicians and general practitioners and reveal the predictors of high grades of burnout among physicians. Subjects and methods: A cross sectional study was carried out. Out of 378 physicians working in two health regions in Kuwait, 200 physicians returned a filled questionnaire, of these 105 were family physicians and the rest were primary health care physicians. Maslach Burnout Inventory–Human Service Survey tool was used to estimate high degree of burnout on three domains, namely emotional exhaustion, depersonalization and personal accomplishment. Results: General practitioners were more likely to suffer from high grades of emotional exhaustion (63.2% than family physicians (19.0%. They also suffered from high grade of depersonalization (65.3% compared with family physicians (27.6%. Those suffering from high grades of personal accomplishment burnout (inverse score constituted 61.1% of primary health care physicians and 33.3% of family physicians. Those suffering from grades for the three burnout domain constituted more than one third of primary health care physicians (36.8% compared with only 5.7% of family physicians. Type of physician job and marital status proved to be significant predictors of high grades of burnout. Conclusion: Burnout is more common among primary care than family physicians. Searching for and eliminating all sources of stress in the primary health care centers in addition to training of these physicians on coping strategies to deal with stress at work seems to be an important

  5. Fabrication of detectors and transistors on high-resistivity silicon

    International Nuclear Information System (INIS)

    Holland, S.

    1988-06-01

    A new process for the fabrication of silicon p-i-n diode radiation detectors is described. The utilization of backside gettering in the fabrication process results in the actual physical removal of detrimental impurities from critical device regions. This reduces the sensitivity of detector properties to processing variables while yielding low diode reverse-leakage currents. In addition, gettering permits the use of processing temperatures compatible with integrated-circuit fabrication. P-channel MOSFETs and silicon p-i-n diodes have been fabricated simultaneously on 10 kΩ/centerreverse arrowdot/cm silicon using conventional integrated-circuit processing techniques. 25 refs., 5 figs

  6. 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.

  7. 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.

  8. 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.

  9. Evaluation of a high resolution silicon PET insert module

    Energy Technology Data Exchange (ETDEWEB)

    Grkovski, Milan, E-mail: milan.grkovski@ijs.si [Jožef Stefan Institute, Ljubljana (Slovenia); Memorial Sloan Kettering Cancer Center, New York, NY (United States); Brzezinski, Karol [IFIC/CSIC, Valencia (Spain); Cindro, Vladimir [Jožef Stefan Institute, Ljubljana (Slovenia); Clinthorne, Neal H. [University of Michigan, Ann Arbor, MI (United States); Kagan, Harris [Ohio State University, Columbus, OH (United States); Lacasta, Carlos [IFIC/CSIC, Valencia (Spain); Mikuž, Marko [Jožef Stefan Institute, Ljubljana (Slovenia); Solaz, Carles [IFIC/CSIC, Valencia (Spain); Studen, Andrej [Jožef Stefan Institute, Ljubljana (Slovenia); Weilhammer, Peter [Ohio State University, Columbus, OH (United States); Žontar, Dejan [Jožef Stefan Institute, Ljubljana (Slovenia)

    2015-07-11

    Conventional PET systems can be augmented with additional detectors placed in close proximity of the region of interest. We developed a high resolution PET insert module to evaluate the added benefit of such a combination. The insert module consists of two back-to-back 1 mm thick silicon sensors, each segmented into 1040 1 mm{sup 2} pads arranged in a 40 by 26 array. A set of 16 VATAGP7.1 ASICs and a custom assembled data acquisition board were used to read out the signal from the insert module. Data were acquired in slice (2D) geometry with a Jaszczak phantom (rod diameters of 1.2–4.8 mm) filled with {sup 18}F-FDG and the images were reconstructed with ML-EM method. Both data with full and limited angular coverage from the insert module were considered and three types of coincidence events were combined. The ratio of high-resolution data that substantially improves quality of the reconstructed image for the region near the surface of the insert module was estimated to be about 4%. Results from our previous studies suggest that such ratio could be achieved at a moderate technological expense by using an equivalent of two insert modules (an effective sensor thickness of 4 mm)

  10. 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...

  11. Operation of a high-purity silicon diode alpha particle detector at 1.4 K

    International Nuclear Information System (INIS)

    Martoff, C.J.; Kaczanowicz, E.; Neuhauser, B.J.; Lopez, E.; Zhang, Y.; Ziemba, F.P.

    1991-01-01

    Detection of alpha particles at temperatures as low as 1.4 K was demonstrated using a specially fabricated Si diode. The diode was 475 mm 2 by 0.280 mm thick, fabricated from high-purity silicon with degenerately doped contacts. This is an important step toward development of dual-mode (ionization plus phonon) silicon detectors for low energy radiation. (orig.)

  12. Carbon−Silicon Core−Shell Nanowires as High Capacity Electrode for Lithium Ion Batteries

    KAUST Repository

    Cui, Li-Feng; Yang, Yuan; Hsu, Ching-Mei; Cui, Yi

    2009-01-01

    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

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

    NARCIS (Netherlands)

    dr. A. Maas; Dr. P. Ester

    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

  14. Study of high energy ion implantation of boron and oxygen in silicon

    International Nuclear Information System (INIS)

    Thevenin, P.

    1991-06-01

    Three aspects of high energy (0.5-3 MeV) light ions ( 11 B + and 16 O + ) implantation in silicon are examined: (1)Spatial repartition; (2) Target damage and (3) Synthesis by oxygen implantation of a buried silicon oxide layer

  15. Development of a process for high capacity arc heater production of silicon for solar arrays

    Science.gov (United States)

    Meyer, T. N.

    1980-01-01

    A high temperature silicon production process using existing electric arc heater technology is discussed. Silicon tetrachloride and a reductant, liquid sodium, were injected into an arc heated mixture of hydrogen and argon. Under these high temperature conditions, a very rapid reaction occurred, yielding silicon and gaseous sodium chloride. Techniques for high temperature separation and collection of the molten silicon were developed. The desired degree of separation was not achieved. The electrical, control and instrumentation, cooling water, gas, SiCl4, and sodium systems are discussed. The plasma reactor, silicon collection, effluent disposal, the gas burnoff stack, and decontamination and safety are also discussed. Procedure manuals, shakedown testing, data acquisition and analysis, product characterization, disassembly and decontamination, and component evaluation are reviewed.

  16. 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.

  17. Silicon detectors

    International Nuclear Information System (INIS)

    Klanner, R.

    1984-08-01

    The status and recent progress of silicon detectors for high energy physics is reviewed. Emphasis is put on detectors with high spatial resolution and the use of silicon detectors in calorimeters. (orig.)

  18. 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.

  19. 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.

  20. Confined high-pressure chemical deposition of hydrogenated amorphous silicon.

    Science.gov (United States)

    Baril, Neil F; He, Rongrui; Day, Todd D; Sparks, Justin R; Keshavarzi, Banafsheh; Krishnamurthi, Mahesh; Borhan, Ali; Gopalan, Venkatraman; Peacock, Anna C; Healy, Noel; Sazio, Pier J A; Badding, John V

    2012-01-11

    Hydrogenated amorphous silicon (a-Si:H) is one of the most technologically important semiconductors. The challenge in producing it from SiH(4) precursor is to overcome a significant kinetic barrier to decomposition at a low enough temperature to allow for hydrogen incorporation into a deposited film. The use of high precursor concentrations is one possible means to increase reaction rates at low enough temperatures, but in conventional reactors such an approach produces large numbers of homogeneously nucleated particles in the gas phase, rather than the desired heterogeneous deposition on a surface. We report that deposition in confined micro-/nanoreactors overcomes this difficulty, allowing for the use of silane concentrations many orders of magnitude higher than conventionally employed while still realizing well-developed films. a-Si:H micro-/nanowires can be deposited in this way in extreme aspect ratio, small-diameter optical fiber capillary templates. The semiconductor materials deposited have ~0.5 atom% hydrogen with passivated dangling bonds and good electronic properties. They should be suitable for a wide range of photonic and electronic applications such as nonlinear optical fibers and solar cells. © 2011 American Chemical Society

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

    International Nuclear Information System (INIS)

    Feege, Nils

    2008-12-01

    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.)

  2. 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.)

  3. Observations of silicon carbide by high resolution transmission electron microscopy

    International Nuclear Information System (INIS)

    Smith, D.J.; Jepps, N.W.; Page, T.F.

    1978-01-01

    High resolution transmission electron microscopy techniques, principally involving direct lattice imaging, have been used as part of a study of the crystallography and phase transformation mechanics of silicon carbide polytypes. In particular, the 3C (cubic) and 6H (hexagonal) polytypes have been examined together with partially transformed structural mixtures. Although direct observation of two-dimensional atomic structures was not possible at an operating voltage of 100 kV, considerable microstructural information has been obtained by careful choice of the experimental conditions. In particular, tilted beam observations of the 0.25 nm lattice fringes have been made in the 3C polytype for two different brace 111 brace plane arrays in order to study the dimensions and coherency of finely-twinned regions together with brace 0006 brace and brace 1 0 bar1 2 brace lattice images in the 6H polytype which allow the detailed stacking operations to be resolved. Lower resolution lattice images formed with axial illumination have also been used to study the nature of the 3C → 6H transformation and results are presented showing that the transformation interface may originate with fine twinning of the 3C structure followed by growth of the resultant 6H regions. Observations have been made of the detailed stepped structure of this interface together with the stacking fault distribution in the resultant 6H material. (author)

  4. 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.

  5. 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.

  6. Functionalization of 2D macroporous silicon under the high-pressure oxidation

    Science.gov (United States)

    Karachevtseva, L.; Kartel, M.; Kladko, V.; Gudymenko, O.; Bo, Wang; Bratus, V.; Lytvynenko, O.; Onyshchenko, V.; Stronska, O.

    2018-03-01

    Addition functionalization after high-pressure oxidation of 2D macroporous silicon structures is evaluated. X-ray diffractometry indicates formation of orthorhombic SiO2 phase on macroporous silicon at oxide thickness of 800-1200 nm due to cylindrical symmetry of macropores and high thermal expansion coefficient of SiO2. Pb center concentration grows with the splitting energy of LO- and TO-phonons and SiO2 thickness in oxidized macroporous silicon structures. This increase EPR signal amplitude and GHz radiation absorption and is promising for development of high-frequency devices and electronically controlled elements.

  7. Development of a Process for a High Capacity Arc Heater Production of Silicon for Solar Arrays

    Science.gov (United States)

    Reed, W. H.

    1979-01-01

    A program was established to develop a high temperature silicon production process using existing electric arc heater technology. Silicon tetrachloride and a reductant (sodium) are injected into an arc heated mixture of hydrogen and argon. Under these high temperature conditions, a very rapid reaction is expected to occur and proceed essentially to completion, yielding silicon and gaseous sodium chloride. Techniques for high temperature separation and collection were developed. Included in this report are: test system preparation; testing; injection techniques; kinetics; reaction demonstration; conclusions; and the project status.

  8. Study on high-silicon boron-containing zeolite by thermogravimetric and IR-spectroscopy techniques

    International Nuclear Information System (INIS)

    Chukin, G.D.; Nefedov, B.K.; Surin, S.A.; Polinina, E.V.; Khusid, B.L.; Sidel'kovskaya, V.G.

    1985-01-01

    The structure identity of initial Na-forms of boron-containing and aluminosilicate high-silicon zeolites is established by thermogravimetric and IR-spectroscopy methods. The presence of boron in Na-forms of high-silicon zeolites is shown to lead to reduction of structure thermal stability. It is noted that thermal stability of the H-form of both high-silicon boron-containing and boron-free zeolites is practically equal and considerably higher than that of Na-forms

  9. Frictional characteristics of silicon graphite lubricated with water at high pressure and high temperature

    International Nuclear Information System (INIS)

    Lee, Jae Seon; Kim, Eun Hyun; Park, Jin Seok; Kim, Jong In

    2001-01-01

    Experimental frictional and wear characteristics of silicon graphite materials is studied in this paper. Those specimens are lubricated with high temperature and highly pressurized water to simulate the same operating condition for the journal bearing and the thrust bearing on the main coolant pump bearing in the newly developing nuclear reactor named SMART(System-integrated Modular Advanced ReacTor). Operating condition of the bearings is realized by the tribometer and the autoclave. Friction coefficient and wear loss are analyzed to choose the best silicon graphite material. Pin on plate test specimens are used and coned disk springs are used to control the applied force on the specimens. Wear loss and wear width are measured by a precision balance and a micrometer. The friction force is measured by the strain gauge which can be used under high temperature and high pressure. Three kinds of silicon graphite materials are examined and compared with each other, and each material shows similar but different results on frictional and wear characteristics

  10. Meta-Analysis of Surgeon Burnout Syndrome and Specialty Differences.

    Science.gov (United States)

    Bartholomew, Alex J; Houk, Anna K; Pulcrano, Marisa; Shara, Nawar M; Kwagyan, John; Jackson, Patrick G; Sosin, Michael

    2018-02-27

    Surgeon burnout compromises the quality of life of physicians and the delivery of care to patients. Burnout rates and interpretation of the Maslach Burnout Inventory (MBI) complicates the interpretation of surgeon burnout. The purpose of this study is to apply a standardized interpretation of severe surgeon burnout termed, "burnout syndrome" to analyze inherent variation within surgical specialties. A systematic literature search was performed using MEDLINE, PsycINFO, and EMBASE to identify studies reporting MBI data by surgical specialty. Data extraction was performed to isolate surgeon specific data. A meta-analysis was performed. A total of 16 cross-sectional studies were included in this meta-analysis, totaling 3581 subjects. A random effects model approximated burnout syndrome at 3.0% (95% CI: 2.0%-5.0%; I 2 = 78.1%). Subscale analysis of emotional exhaustion, depersonalization, and personal accomplishment indicated subscale burnout in 30.0% (CI: 25.0%-36.0%; I 2 = 93.2%), 34.0% (CI: 25.0%-43.0%; I 2 = 96.9%), and 25.0% (CI: 18.0%-32.0%; I 2 = 96.5%) of surgeons, respectively. Significant differences (p burnout termed "burnout syndrome," although surgeon burnout may occur in up to 34% of surgeons, characterized by high burnout in 1 of 3 subscales. Surgical specialties have significantly different rates of burnout subscales. Future burnout studies should target the specialty-specific level to understand inherent differences in an effort to better understand methods of improving surgeon burnout. Copyright © 2018 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  11. Proton-irradiation technology for high-frequency high-current silicon welding diode manufacturing

    International Nuclear Information System (INIS)

    Lagov, P B; Drenin, A S; Zinoviev, M A

    2017-01-01

    Different proton irradiation regimes were tested to provide more than 20 kHz-frequency, soft reverse recovery “snap-less” behavior, low forward voltage drop and leakage current for 50 mm diameter 7 kA/400 V welding diode Al/Si/Mo structure. Silicon diode with such parameters is very suitable for high frequency resistance welding machines of new generation for robotic welding. (paper)

  12. Proton-irradiation technology for high-frequency high-current silicon welding diode manufacturing

    Science.gov (United States)

    Lagov, P. B.; Drenin, A. S.; Zinoviev, M. A.

    2017-05-01

    Different proton irradiation regimes were tested to provide more than 20 kHz-frequency, soft reverse recovery “snap-less” behavior, low forward voltage drop and leakage current for 50 mm diameter 7 kA/400 V welding diode Al/Si/Mo structure. Silicon diode with such parameters is very suitable for high frequency resistance welding machines of new generation for robotic welding.

  13. Burnout for Nurses

    OpenAIRE

    Lískovcová, Jana

    2013-01-01

    The bachelor thesis has theoretical as well as empirical character. Its content focuses on the issue of burnout syndrome in nurses. The theoretical part of the thesis focuses on personality profile of a general nurse. I first characterize her personality, characters, psychological problems related to the profession. The next chapter focused on burnout syndrome deals with the causes of burnout syndrome, its symptoms in the individual phases of burning out and the results of burnout together wi...

  14. Burnout and depression

    OpenAIRE

    入江, 正洋

    2017-01-01

    Recently, according to the increase in physical and psychological fatigue due to overwork and/or emotional labor, burnout has been received broad attention and widely infiltrated the popular culture. Despite an extended concept of burnout, however, the distinction between burnout and depression remains inconclusive. Furthermore, in spite of a rapid increase in research dedicated physical and biological aspects in addition to symptomatic and psychosocial ones of burnout, a clear difference bet...

  15. Highly Manufacturable Deep (Sub-Millimeter) Etching Enabled High Aspect Ratio Complex Geometry Lego-Like Silicon Electronics

    KAUST Repository

    Ghoneim, Mohamed T.; Hussain, Muhammad Mustafa

    2017-01-01

    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

  16. Crystal growth for high-efficiency silicon solar cells workshop: Summary

    Science.gov (United States)

    Dumas, K. A.

    1985-01-01

    The state of the art in the growth of silicon crystals for high-efficiency solar cells are reviewed, sheet requirements are defined, and furture areas of research are identified. Silicon sheet material characteristics that limit cell efficiencies and yields were described as well as the criteria for the ideal sheet-growth method. The device engineers wish list to the material engineer included: silicon sheet with long minority carrier lifetime that is uniform throughout the sheet, and which doesn't change during processing; and sheet material that stays flat throughout device processing, has uniform good mechanical strength, and is low cost. Impurities in silicon solar cells depreciate cell performance by reducing diffusion length and degrading junctions. The impurity behavior, degradation mechanisms, and variations in degradation threshold with diffusion length for silicon solar cells were described.

  17. High yield silicon carbide from alkylated or arylated pre-ceramic polymer

    International Nuclear Information System (INIS)

    Baney, R.H.; Gaul, J.H.

    1982-01-01

    Alkylated or arylated methylpolysilanes which exhibit ease of handling and are used to obtain silicon carbide ceramic materials in high yields contain 0 to 60 mole percent (CH 3 ) 2 Si double bond units and 40 to 100 mole percent CH 3 Si triple bond units, wherein there is also bonded to the silicon atoms other silicon atoms and additional alkyl radicals of 1 to 4 carbon atoms or phenyl. They may be prepared by reaction of a Grignard reagent RMgX, where X is halogen and R is Csub(1-4)-alkyl or phenyl, with a starting material which is a solid at 25 0 C, and is identical to the product except that the remaining bonds on the silicon atoms are attached to another silicon atom, or a chlorine or a bromine atom. Ceramics result from heating the polysilane products to 1200 0 C, optionally with fillers. (author)

  18. 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...

  19. 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…

  20. Burnout and Its Contributing Factors Among Midlevel Academic Nurse Leaders.

    Science.gov (United States)

    Flynn, Linda; Ironside, Pamela M

    2018-01-01

    Amid concerns regarding administrator shortages, a survey conducted by the American Association of Colleges of Nursing indicates that 10% of all vacant faculty positions are those that include administrative responsibilities. This study was designed to determine the frequency, predictors, and potential retention consequences of burnout among midlevel academic nurse leaders, such as assistant deans, associate deans, and others. The sample consisted of 146 midlevel academic nurse leaders from 29 schools of nursing. Burnout was measured by the emotional exhaustion subscale of the Maslach Burnout Inventory. Logistic regression models were estimated to determine effects of study variables on burnout and intent to leave. Dissatisfaction with workload, dissatisfaction with work-life balance, and hours typically worked per week increased odds of burnout. Burnout was associated with intent to leave. High workloads and long work weeks are increasing the odds of burnout among midlevel academic nurse leaders. [J Nurs Educ. 2018;57(1):28-34.]. Copyright 2018, SLACK Incorporated.

  1. 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...

  2. Silicon Detector System for High Rate EXAFS Applications

    OpenAIRE

    Pullia, A.; Kraner, H. W.; Siddons, D. P.; Furenlid, L. R.; Bertuccio, G.

    1995-01-01

    A multichannel silicon pad detector for EXAFS (Extended X-ray Absorption Fine Structure) applications has been designed and built. The X-ray spectroscopic measurements demonstrate that an adequate energy resolution of 230 eV FWHM (corresponding to 27 rms electrons in silicon) can be achieved reliably at −35 °C. A resolution of 190 eV FWHM (corresponding to 22 rms electrons) has been obtained from individual pads at −35 °C. At room temperature (25 °C) an average energy resolution of 380 eV FWH...

  3. 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

    permittivity and the Young's modulus of the elastomer. One system that potentially achieves this involves interpenetrating polymer networks (IPNs), based on commercial silicone elastomers and ionic networks from amino- and carboxylic acid-functional silicones. The applicability of these materials as DEs...... are obtained while dielectric breakdown strength and Young's modulus are not compromised. These good overall properties stem from the softening effect and very high permittivity of ionic networks – as high as ε′ = 7500 at 0.1 Hz – while the silicone elastomer part of the IPN provides mechanical integrity...

  4. Talc-silicon glass-ceramic waste forms for immobilization of high- level calcined waste

    International Nuclear Information System (INIS)

    Vinjamuri, K.

    1993-06-01

    Talc-silicon glass-ceramic waste forms are being evaluated as candidates for immobilization of the high level calcined waste stored onsite at the Idaho Chemical Processing Plant. These glass-ceramic waste forms were prepared by hot isostatically pressing a mixture of simulated nonradioactive high level calcined waste, talc, silicon and aluminum metal additives. The waste forms were characterized for density, chemical durability, and glass and crystalline phase compositions. The results indicate improved density and chemical durability as the silicon content is increased

  5. 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.

  6. High-Sensitivity Temperature-Independent Silicon Photonic Microfluidic Biosensors

    Science.gov (United States)

    Kim, Kangbaek

    Optical biosensors that can precisely quantify the presence of specific molecular species in real time without the need for labeling have seen increased use in the drug discovery industry and molecular biology in general. Of the many possible optical biosensors, the TM mode Si biosensor is shown to be very attractive in the sensing application because of large field amplitude on the surface and cost effective CMOS VLSI fabrication. Noise is the most fundamental factor that limits the performance of sensors in development of high-sensitivity biosensors, and noise reduction techniques require precise studies and analysis. One such example stems from thermal fluctuations. Generally SOI biosensors are vulnerable to ambient temperature fluctuations because of large thermo-optic coefficient of silicon (˜2x10 -4 RIU/K), typically requiring another reference ring and readout sequence to compensate temperature induced noise. To address this problem, we designed sensors with a novel TM-mode shallow-ridge waveguide that provides both large surface amplitude for bulk and surface sensing. With proper design, this also provides large optical confinement in the aqueous cladding that renders the device athermal using the negative thermo-optic coefficient of water (~ --1x10-4RIU/K), demonstrating cancellation of thermo-optic effects for aqueous solution operation near 300K. Additional limitations resulting from mechanical actuator fluctuations, stability of tunable lasers, and large 1/f noise of lasers and sensor electronics can limit biosensor performance. Here we also present a simple harmonic feedback readout technique that obviates the need for spectrometers and tunable lasers. This feedback technique reduces the impact of 1/f noise to enable high-sensitivity, and a DSP lock-in with 256 kHz sampling rate can provide down to micros time scale monitoring for fast transitions in biomolecular concentration with potential for small volume and low cost. In this dissertation, a novel

  7. Towards an optimum silicon heterojunction solar cell configuration for high temperature and high light intensity environment

    KAUST Repository

    Abdallah, Amir

    2017-09-22

    We report on the performance of Silicon Heterojunction (SHJ) solar cell under high operating temperature and varying irradiance conditions typical to desert environment. In order to define the best solar cell configuration that resist high operating temperature conditions, two different intrinsic passivation layers were tested, namely, an intrinsic amorphous silicon a-SiO:H with CO/SiH ratio of 0.4 and a-SiOx:H with CO/SiH ratio of 0.8, and the obtained performance were compared with those of a standard SHJ cell configuration having a-Si:H passivation layer. Our results showed how the short circuit current density J, and fill factor FF temperature-dependency are impacted by the cell\\'s configuration. While the short circuit current density J for cells with a-SiO:H layers was found to improve as compared with that of standard a-Si:H layer, introducing the intrinsic amorphous silicon oxide (a-SiO:H) layer with CO/SiH ratio of 0.8 has resulted in a reduction of the FF at room temperature due to hindering the carrier transport by the band structure. Besides, this FF was found to improve as the temperature increases from 15 to 45°C, thus, a positive FF temperature coefficient.

  8. Towards an optimum silicon heterojunction solar cell configuration for high temperature and high light intensity environment

    KAUST Repository

    Abdallah, Amir; Daif, Ounsi El; Aï ssa, Brahim; Kivambe, Maulid; Tabet, Nouar; Seif, Johannes; Haschke, Jan; Cattin, Jean; Boccard, Mathieu; De Wolf, Stefaan; Ballif, Christophe

    2017-01-01

    We report on the performance of Silicon Heterojunction (SHJ) solar cell under high operating temperature and varying irradiance conditions typical to desert environment. In order to define the best solar cell configuration that resist high operating temperature conditions, two different intrinsic passivation layers were tested, namely, an intrinsic amorphous silicon a-SiO:H with CO/SiH ratio of 0.4 and a-SiOx:H with CO/SiH ratio of 0.8, and the obtained performance were compared with those of a standard SHJ cell configuration having a-Si:H passivation layer. Our results showed how the short circuit current density J, and fill factor FF temperature-dependency are impacted by the cell's configuration. While the short circuit current density J for cells with a-SiO:H layers was found to improve as compared with that of standard a-Si:H layer, introducing the intrinsic amorphous silicon oxide (a-SiO:H) layer with CO/SiH ratio of 0.8 has resulted in a reduction of the FF at room temperature due to hindering the carrier transport by the band structure. Besides, this FF was found to improve as the temperature increases from 15 to 45°C, thus, a positive FF temperature coefficient.

  9. Flexible semi-transparent silicon (100) fabric with high-k/metal gate devices

    KAUST Repository

    Rojas, Jhonathan Prieto; Hussain, Muhammad Mustafa

    2013-01-01

    (100) wafers and then released as continuous, mechanically flexible, optically semi-transparent and high thermal budget compatible silicon fabric with devices. This is the first ever demonstration with this set of materials which allows full degree

  10. Improvements in numerical modelling of highly injected crystalline silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Altermatt, P.P. [University of New South Wales, Centre for Photovoltaic Engineering, 2052 Sydney (Australia); Sinton, R.A. [Sinton Consulting, 1132 Green Circle, 80303 Boulder, CO (United States); Heiser, G. [University of NSW, School of Computer Science and Engineering, 2052 Sydney (Australia)

    2001-01-01

    We numerically model crystalline silicon concentrator cells with the inclusion of band gap narrowing (BGN) caused by injected free carriers. In previous studies, the revised room-temperature value of the intrinsic carrier density, n{sub i}=1.00x10{sup 10}cm{sup -3}, was inconsistent with the other material parameters of highly injected silicon. In this paper, we show that high-injection experiments can be described consistently with the revised value of n{sub i} if free-carrier induced BGN is included, and that such BGN is an important effect in silicon concentrator cells. The new model presented here significantly improves the ability to model highly injected silicon cells with a high level of precision.

  11. TEM investigation of aluminium containing precipitates in high aluminium doped silicon carbide

    International Nuclear Information System (INIS)

    Wong-Leung, J.; FitzGerald, J.D.

    2002-01-01

    Full text: Silicon carbide is a promising semiconductor material for applications in high temperature and high power devices. The successful growth of good quality epilayers in this material has enhanced its potential for device applications. As a novel semiconductor material, there is a need for studying its basic physical properties and the role of dopants in this material. In this study, silicon carbide epilayers were grown on 4H-SiC wafers of (0001) orientation with a miscut angle of 8 deg at a temperature of 1550 deg C. The epilayers contained regions of high aluminium doping well above the solubility of aluminium in silicon carbide. High temperature annealing of this material resulted in the precipitation of aluminium in the wafers. The samples were analysed by secondary ion mass spectrometry and transmission electron microscopy. Selected area diffraction studies show the presence of aluminium carbide and aluminium silicon carbide phases. Copyright (2002) Australian Society for Electron Microscopy Inc

  12. Thermophysical Properties of Molten Silicon Measured by JPL High Temperature Electrostatic Levitator

    Science.gov (United States)

    Rhim, W. K.; Ohsaka, K.

    1999-01-01

    Five thermophysical properties of molten silicon measured by the High Temperature Electrostatic Levitator (HTESL) at JPL are presented. The properties measured are the density, the constant pressure specific heat capacity, the hemispherical total emissivity, the surface tension and the viscosity.

  13. Controlled localised melting in silicon by high dose germanium implantation and flash lamp annealing

    International Nuclear Information System (INIS)

    Voelskow, Matthias; Skorupa, Wolfgang; Pezoldt, Joerg; Kups, Thomas

    2009-01-01

    High intensity light pulse irradiation of monocrystalline silicon wafers is usually accompanied by inhomogeneous surface melting. The aim of the present work is to induce homogeneous buried melting in silicon by germanium implantation and subsequent flash lamp annealing. For this purpose high dose, high energy germanium implantation has been employed to lower the melting temperature of silicon in a predetermined depth region. Subsequent flash lamp irradiation at high energy densities leads to local melting of the germanium rich buried layer, whereby the thickness of the molten layer depends on the irradiation energy density. During the cooling down epitaxial crystallization takes place resulting in a largely defect-free layer. The combination of buried melting and dopant segregation has the potential to produce unusually buried doping profiles or to create strained silicon structures.

  14. Development of Silicon Sensor Characterization System for Future High Energy Physics Experiments

    OpenAIRE

    Preeti kumari; Kavita Lalwani; Ranjeet Dalal; Geetika Jain; Ashutosh Bhardwaj; Kirti Ranjan

    2015-01-01

    The Compact Muon Solenoid (CMS) is one of the general purpose experiments at the Large Hadron Collider (LHC), CERN and has its Tracker built of all silicon strip and pixel sensors. Si sensors are expected to play extremely important role in the upgrades of the existing Tracker for future high luminosity environment and will also be used in future lepton colliders. However, properties of the silicon sensors have to be carefully understood before they can be put in the extremely high luminos...

  15. Scaling of black silicon processing time by high repetition rate femtosecond lasers

    Directory of Open Access Journals (Sweden)

    Nava Giorgio

    2013-11-01

    Full Text Available Surface texturing of silicon substrates is performed by femtosecond laser irradiation at high repetition rates. Various fabrication parameters are optimized in order to achieve very high absorptance in the visible region from the micro-structured silicon wafer as compared to the unstructured one. A 70-fold reduction of the processing time is demonstrated by increasing the laser repetition rate from 1 kHz to 200 kHz. Further scaling up to 1 MHz can be foreseen.

  16. Surface engineered porous silicon for stable, high performance electrochemical supercapacitors

    Science.gov (United States)

    Oakes, Landon; Westover, Andrew; Mares, Jeremy W.; Chatterjee, Shahana; Erwin, William R.; Bardhan, Rizia; Weiss, Sharon M.; Pint, Cary L.

    2013-10-01

    Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10-40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage.

  17. Surface engineered porous silicon for stable, high performance electrochemical supercapacitors

    Science.gov (United States)

    Oakes, Landon; Westover, Andrew; Mares, Jeremy W.; Chatterjee, Shahana; Erwin, William R.; Bardhan, Rizia; Weiss, Sharon M.; Pint, Cary L.

    2013-01-01

    Silicon materials remain unused for supercapacitors due to extreme reactivity of silicon with electrolytes. However, doped silicon materials boast a low mass density, excellent conductivity, a controllably etched nanoporous structure, and combined earth abundance and technological presence appealing to diverse energy storage frameworks. Here, we demonstrate a universal route to transform porous silicon (P-Si) into stable electrodes for electrochemical devices through growth of an ultra-thin, conformal graphene coating on the P-Si surface. This graphene coating simultaneously passivates surface charge traps and provides an ideal electrode-electrolyte electrochemical interface. This leads to 10–40X improvement in energy density, and a 2X wider electrochemical window compared to identically-structured unpassivated P-Si. This work demonstrates a technique generalizable to mesoporous and nanoporous materials that decouples the engineering of electrode structure and electrochemical surface stability to engineer performance in electrochemical environments. Specifically, we demonstrate P-Si as a promising new platform for grid-scale and integrated electrochemical energy storage. PMID:24145684

  18. High-performance RF coil inductors on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Malba, V.; Young, D.; Ou, J.J.; Bernhardt, A.F.; Boser, B.E.

    1998-03-01

    Strong demand for wireless communication devices has motivated research directed toward monolithic integration of transceivers. The fundamental electronic component least compatible with silicon integrated circuits is the inductor, although a number of inductors are required to implement oscillators, filters and matching networks in cellular devices. Spiral inductors have been integrated into the silicon IC metallization sequence but have not performed adequately due to coupling to the silicon which results in parasitic capacitance and loss. We have, for the first time, fabricated three dimensional coil inductors on silicon which have significantly lower capacitive coupling and loss and which now exceed the requirements of potential applications. Quality factors of 30 at 1 GHz have been measured in single turn devices and Q > 16 in 2 and 4 turn devices. The reduced Q for multiturn devices appears to be related to eddy currents in outer turns generated by magnetic fields from current in neighboring turns. Higher Q values significantly in excess of 30 are anticipated using modified coil designs.

  19. Development of high efficiency solar cells on silicon web

    Science.gov (United States)

    Rohatgi, A.; Meier, D. L.; Campbell, R. B.; Schmidt, D. N.; Rai-Choudhury, P.

    1984-01-01

    Web base material is being improved with a goal toward obtaining solar cell efficiencies in excess of 18% (AM1). Carrier loss mechanisms in web silicon was investigated, techniques were developed to reduce carrier recombination in the web, and web cells were fabricated using effective surface passivation. The effect of stress on web cell performance was also investigated.

  20. Nursing specialty and burnout.

    Science.gov (United States)

    Browning, Laura; Ryan, Carey S; Thomas, Scott; Greenberg, Martin; Rolniak, Susan

    2007-03-01

    We examined the relationship between perceived control and burnout among three nursing specialties: nurse practitioners, nurse managers, and emergency nurses. Survey data were collected from 228 nurses from 30 states. Findings indicated that emergency nurses had the least control and the highest burnout, whereas nurse practitioners had the most control and the least burnout. Mediational analyses showed that expected control, hostility, and stressor frequency explained differences between specialties in burnout. The implications of these findings for interventions that reduce burnout and promote nursing retention are discussed.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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. (paper)

  2. Behaviour and burnout in medical students.

    Science.gov (United States)

    Cecil, Jo; McHale, Calum; Hart, Jo; Laidlaw, Anita

    2014-01-01

    Burnout is prevalent in doctors and can impact on job dissatisfaction and patient care. In medical students, burnout is associated with poorer self-rated health; however, it is unclear what factors influence its development. This study investigated whether health behaviours predict burnout in medical students. Medical students (n=356) at the Universities of St Andrews and Manchester completed an online questionnaire assessing: emotional exhaustion (EE), depersonalisation (DP), personal accomplishment (PA), alcohol use, physical activity, diet, and smoking. Approximately 55% (54.8%) of students reported high levels of EE, 34% reported high levels of DP, and 46.6% reported low levels of PA. Linear regression analysis revealed that year of study, physical activity, and smoking status significantly predicted EE whilst gender, year of study, and institution significantly predicted DP. PA was significantly predicted by alcohol binge score, year of study, gender, and physical activity. Burnout is present in undergraduate medical students in the United Kingdom, and health behaviours, particularly physical activity, predict components of burnout. Gender, year of study, and institution also appear to influence the prevalence of burnout. Encouraging medical students to make healthier lifestyle choices early in their medical training may reduce the likelihood of the development of burnout.

  3. 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...

  4. Relaxation of the Shallow Acceptor Center Magnetic Moment in a Highly Doped Silicon

    CERN Document Server

    Mamedov, T N; Herlach, D; Gorelkin, V N; Gritsaj, K I; Duginov, V N; Kormann, O; Major, J V; Stoikov, A V; Zimmermann, U

    2001-01-01

    Results on the temperature dependence of the residual polarization of negative muons in crystalline silicon with germanium, boron and phosphorus impurities are presented. The measurements were carried out in a magnetic field of 0.1 T transverse to the direction of the muon spin in the temperature range 4.2-300 K. It is found that in a silicon sample with a high concentration of germanium impurity (9\\cdot 10^{19} cm^{-3}), as in the samples of n- and p-type silicon with impurity concentrations up to \\sim 10^{17} cm^{-3}, the relaxation rate \

  5. Silicon carbide production by Self-Propagating High Temperature (SHS) technique

    International Nuclear Information System (INIS)

    Lima, Eduardo de Souza; Schneider, Pedro Luiz; Mattoso, Irani Guedes; Costa, Carlos Roberto Correia da; Louro, Luis Henrique Leme

    1997-01-01

    Samples of silicon carbide (SiC) were synthesized from a mixture of silicon and carbon powders, using the Self-Propagating High Temperature Synthesis (SHS) technique. Three mixtures were tried, using silicon particles of the same average size but carbon particles of different average sizes. The method tried is characterized by an ignition temperature of 1450 deg C and the short duration of the synthesis ( 2-3 min). The samples were characterized by X-ray diffraction and scattering electron microscopy. (author)

  6. 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

  7. Burnout Among Anesthetists and Intensive Care Physicians.

    Science.gov (United States)

    Mikalauskas, Audrius; Benetis, Rimantas; Širvinskas, Edmundas; Andrejaitienė, Judita; Kinduris, Šarūnas; Macas, Andrius; Padaiga, Žilvinas

    2018-01-01

    Burnout is a syndrome of depersonalization, emotional exhaustion, and low personal accomplishment. Little is known about burnout in physicians. Our objective was to determine the prevalence of burnout among anesthetists and intensive care physicians, and associations between burnout and personal, as well as professional, characteristics. In total, 220 anesthetists and intensive care physicians were contacted by email, asking them to participate in the study. For depression screening the PHQ-2 questionnaire, for problem drinking, CAGE items were used. Burnout was measured by the Maslach Burnout Inventory. Overall, 34% anesthetists and intensive care physicians indicated high levels of emotional exhaustion, 25% indicated high levels of depersonalization, and 38% showed low personal accomplishment. Burnout was found more frequent among subjects with problem drinking (OR 3.2, 95% CI 1.5-6.8), depressiveness (OR 10.2, 95% CI 4.6-22.6), cardiovascular disorders (OR 3.4, 95% CI 1.7-7.1), and digestive disorders (OR 2.2, 95% CI 1.2-4.0). Some favorite after-work activities positively correlated with burnout, such as sedative medications abuse (OR 4.8, 95% CI 1.8-12.5), alcohol abuse (OR 2.4, 95% CI 1.3-4.5), eating more than usual (OR 1.9, 95% CI 1.1-3.5), and transferring the accumulated stress to relatives (OR 2.8, 95% CI 1.4-5.5). In contrast, reading of non-medical literature seemed to have a protective effect (OR 0.5, 95% CI 0.2-0.9). Burnout was highly prevalent among anesthetists and intensive care physicians with two fifths of them meeting diagnostic criteria. It was strongly correlated with problem drinking, depressiveness, cardiovascular and digestive disorders, use of sedatives and overeating.

  8. Silicon detectors for x and gamma-ray with high radiation resistance

    International Nuclear Information System (INIS)

    Cimpoca, Valerica; Popescu, Ion V.; Ruscu, Radu

    2001-01-01

    Silicon detectors are widely used in X and gamma-ray spectroscopy for direct detection or coupled with scintillators in high energy nuclear physics (modern collider experiments are representative), medicine and industrial applications. In X and gamma dosimetry, a low detection limit (under 6 KeV) with silicon detectors becomes available. Work at the room temperature is now possible due to the silicon processing evolution, which assures low reverse current and high life time of carriers. For several years, modern semiconductor detectors have been the primary choice for the measurement of nuclear radiation in various scientific fields. Nowadays the recently developed high resolution silicon detectors found their way in medical applications. As a consequence many efforts have been devoted to the development of high sensitivity and radiation hardened X and gamma-ray detectors for the energy range of 5 - 150 keV. The paper presents some results concerning the technology and behaviour of X and Gamma ray silicon detectors used in physics research, industrial and medical radiography. The electrical characteristics of these detectors, their modification after exposure to radiation and the results of spectroscopic X and Gamma-ray measurements are discussed. The results indicated that the proposed detectors enables the development of reliable silicon detectors to be used in controlling the low and high radiation levels encountered in a lot of application

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

    NARCIS (Netherlands)

    Vermeer, Rolf; Berenschot, Johan W.; Sarajlic, Edin; Tas, Niels Roelof; Jansen, Henricus V.

    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 $\\langle$111$\\rangle$ silicon wafers a dedicated process is developed to fabricate molds in the silicon wafer that have a flat triangular bottom

  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. X- and gamma-ray N+PP+ silicon detectors with high radiation resistance

    International Nuclear Information System (INIS)

    Petris, M.; Ruscu, R.; Moraru, R.; Cimpoca, V.

    1998-01-01

    We have investigated the use of p-type silicon detectors as starting material for X-and gamma-ray detectors because of several potential benefits it would bring: 1. high purity p-type silicon grown by the float-zone process exhibits better radial dopant uniformity than n-type float-zone silicon; 2. it is free of radiation damage due to the neutron transmutation doping process and behaves better in a radiation field because mainly acceptor like centers are created through the exposure and the bulk material type inversion does not occur as in the n-type silicon. But the p-type silicon, in combination with a passivating layer of silicon dioxide, leads to a more complex detector layout since the positive charge in the oxide causes an inversion in the surface layer under the silicon dioxide. Consequently, it would be expected that N + P diodes have a higher leakage current than P + N ones. All these facts have been demonstrated experimentally. These features set stringent requirements for the technology of p-type silicon detectors. Our work presents two new geometries and an improved technology for p-type high resistivity material to obtain low noise radiation detectors. Test structures were characterized before and after the gamma exposure with a cumulative dose in the range 10 4 - 5 x 10 6 rad ( 60 Co). Results indicate that proposed structures and their technology enable the development of reliable N + PP + silicon detectors. For some samples (0.8 - 12 mm 2 ), extremely low reverse currents were obtained and, in combination with a low noise charge preamplifier, the splitting of 241 Am X-ray lines was possible and also the Mn Kα line (5.9 keV) was extracted from the noise with a 1.9 keV FWHM at the room temperature. An experimental model of a nuclear probe based on these diodes was designed for X-ray detection applications. (authors)

  12. Doping efficiency analysis of highly phosphorous doped epitaxial/amorphous silicon emitters grown by PECVD for high efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    El-Gohary, H.G.; Sivoththaman, S. [Waterloo Univ., ON (Canada). Dept. of Electrical and Computer Engineering

    2008-08-15

    The efficient doping of hydrogenated amorphous and crystalline silicon thin films is a key factor in the fabrication of silicon solar cells. The most popular method for developing those films is plasma enhanced chemical vapor deposition (PECVD) because it minimizes defect density and improves doping efficiency. This paper discussed the preparation of different structure phosphorous doped silicon emitters ranging from epitaxial to amorphous films at low temperature. Phosphine (PH{sub 3}) was employed as the doping gas source with the same gas concentration for both epitaxial and amorphous silicon emitters. The paper presented an analysis of dopant activation by applying a very short rapid thermal annealing process (RTP). A spreading resistance profile (SRP) and SIMS analysis were used to detect both the active dopant and the dopant concentrations, respectively. The paper also provided the results of a structural analysis for both bulk and cross-section at the interface using high-resolution transmission electron microscopy and Raman spectroscopy, for epitaxial and amorphous films. It was concluded that a unity doping efficiency could be achieved in epitaxial layers by applying an optimized temperature profile using short time processing rapid thermal processing technique. The high quality, one step epitaxial layers, led to both high conductive and high doping efficiency layers.

  13. Burnout, job satisfaction, and medical malpractice among physicians.

    Science.gov (United States)

    Chen, Kuan-Yu; Yang, Che-Ming; Lien, Che-Hui; Chiou, Hung-Yi; Lin, Mau-Roung; Chang, Hui-Ru; Chiu, Wen-Ta

    2013-01-01

    Our objective was to estimate the incidence of recent burnout in a large sample of Taiwanese physicians and analyze associations with job related satisfaction and medical malpractice experience. We performed a cross-sectional survey. Physicians were asked to fill out a questionnaire that included demographic information, practice characteristics, burnout, medical malpractice experience, job satisfaction, and medical error experience. There are about 2% of total physicians. Physicians who were members of the Taiwan Society of Emergency Medicine, Taiwan Surgical Association, Taiwan Association of Obstetrics and Gynecology, The Taiwan Pediatric Association, and Taiwan Stroke Association, and physicians of two medical centers, three metropolitan hospitals, and two local community hospitals were recruited. There is high incidence of burnout among Taiwan physicians. In our research, Visiting staff (VS) and residents were more likely to have higher level of burnout of the emotional exhaustion (EE) and depersonalization (DP), and personal accomplishment (PA). There was no difference in burnout types in gender. Married had higher-level burnout in EE. Physicians who were 20~30 years old had higher burnout levels in EE, those 31~40 years old had higher burnout levels in DP, and PA. Physicians who worked in medical centers had a higher rate in EE, DP, and who worked in metropolitan had higher burnout in PA. With specialty-in-training, physicians had higher-level burnout in EE and DP, but lower burnout in PA. Physicians who worked 13-17hr continuously had higher-level burnout in EE. Those with ≥41 times/week of being on call had higher-level burnout in EE and DP. Physicians who had medical malpractice experience had higher-level burnout in EE, DP, and PA. Physicians who were not satisfied with physician-patient relationships had higher-level burnout than those who were satisfied. Physicians in Taiwan face both burnout and a high risk in medical malpractice. There is high

  14. Porous silicon structures with high surface area/specific pore size

    Science.gov (United States)

    Northrup, M.A.; Yu, C.M.; Raley, N.F.

    1999-03-16

    Fabrication and use of porous silicon structures to increase surface area of heated reaction chambers, electrophoresis devices, and thermopneumatic sensor-actuators, chemical preconcentrates, and filtering or control flow devices. In particular, such high surface area or specific pore size porous silicon structures will be useful in significantly augmenting the adsorption, vaporization, desorption, condensation and flow of liquids and gases in applications that use such processes on a miniature scale. Examples that will benefit from a high surface area, porous silicon structure include sample preconcentrators that are designed to adsorb and subsequently desorb specific chemical species from a sample background; chemical reaction chambers with enhanced surface reaction rates; and sensor-actuator chamber devices with increased pressure for thermopneumatic actuation of integrated membranes. Examples that benefit from specific pore sized porous silicon are chemical/biological filters and thermally-activated flow devices with active or adjacent surfaces such as electrodes or heaters. 9 figs.

  15. 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.

  16. Impurity effects in silicon for high efficiency solar cells

    Science.gov (United States)

    Hopkins, R. H.; Rohatgi, A.

    1986-01-01

    Model analyses indicate that sophisticated solar cell designs including, e.g., back surface fields, optical reflectors, surface passivation, and double layer antireflective coatings can produce devices with conversion efficiencies above 20 percent (AM1). To realize this potential, the quality of the silicon from which the cells are made must be improved; and these excellent electrical properties must be maintained during device processing. As the cell efficiency rises, the sensitivity to trace contaminants also increases. For example, the threshold Ti impurity concentration at which cell performance degrades is more than an order of magnitude lower for an 18-percent cell. Similar behavior occurs for numerous other metal species which introduce deep level traps that stimulate the recombination of photogenerated carriers in silicon. Purification via crystal growth in conjunction with gettering steps to preserve the large diffusion length of the as-grown material can lead to the production of devices with efficiencies aboved 18 percent, as has been verified experimentally.

  17. Silicon Detector System for High Rate EXAFS Applications.

    Science.gov (United States)

    Pullia, A; Kraner, H W; Siddons, D P; Furenlid, L R; Bertuccio, G

    1995-08-01

    A multichannel silicon pad detector for EXAFS (Extended X-ray Absorption Fine Structure) applications has been designed and built. The X-ray spectroscopic measurements demonstrate that an adequate energy resolution of 230 eV FWHM (corresponding to 27 rms electrons in silicon) can be achieved reliably at -35 °C. A resolution of 190 eV FWHM (corresponding to 22 rms electrons) has been obtained from individual pads at -35 °C. At room temperature (25 °C) an average energy resolution of 380 eV FWHM is achieved and a resolution of 350 eV FWHM (41 rms electrons) is the best performance. A simple cooling system constituted of Peltier cells is sufficient to reduce the reverse currents of the pads and their related shot noise contribution, in order to achieve resolutions better than 300 eV FWHM which is adequate for the EXAFS applications.

  18. Burnout in the working population: relations to psychosocial work factors.

    Science.gov (United States)

    Lindblom, Karin M; Linton, Steven J; Fedeli, Cecilia; Bryngelsson, Ing-Liss

    2006-01-01

    This study investigated levels of burnout in the general population irrespective of occupation and relations between burnout and psychosocial work factors. A cross-sectional survey featuring sleep problems, psychological distress, burnout (Maslach Burnout Inventory-General Survey), and psychosocial factors at work, was mailed to a random sample of 3,000 participants, aged 20-60. Response rate was 61%. A high level (18%), a low level (19%), and an intermediate group (63%) for burnout were constructed. The high level group was associated with those who were > 50 years old, women, those experiencing psychological distress, and those with a poor psychosocial work climate. The analyses on variables significant in previous analyses showed that the high level group was strongly related to high demands, low control, lack of social support, and disagreeing about values at the workplace even when accounting for age, gender, and psychological distress. We conclude that psychosocial work factors are important in association to burnout regardless of occupation.

  19. High resolution silicon detectors for colliding beam physics

    International Nuclear Information System (INIS)

    Amendolia, S.R.; Bedeschi, F.; Bertolucci, E.; Bettoni, D.; Bosisio, L.; Bottigli, U.; Bradaschia, C.; Dell'Orso, M.; Fidecaro, F.; Foa, L.; Focardi, E.; Giannetti, P.; Giorgi, M.A.; Marrocchesi, P.S.; Menzione, A.; Raso, G.; Ristori, L.; Scribano, A.; Stefanini, A.; Tenchini, R.; Tonelli, G.; Triggiani, G.

    1984-01-01

    Resolution and linearity of the position measurement of Pisa multi-electrode silicon detectors are presented. The detectors are operated in slightly underdepleted mode and take advantage of their intrinsic resistivity for resistive charge partition between adjacent strips. 22 μm resolution is achieved with readout lines spaced 300 μm. Possible applications in colliding beam experiments for the detection of secondary vertices are discussed. (orig.)

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

    Science.gov (United States)

    2017-03-14

    optical bandwidth of the erbium-doped- fiber -amplifier with densely-spaced frequency channels. To extend the spectral capacity of the Si-on-insulator...associated with non-uniform undercut at the taper tip across the chip after wet etching the active region. Figure 14. Normalized optical emission...Hutchinson, J., Shin, J.-H., Fish, G., and Fang, A., “Integrated silicon photonic laser sources for telecom and datacom,” in [National Fiber Optic

  1. Operation of a high-purity silicon diode alpha particle detector at 1. 4 K

    Energy Technology Data Exchange (ETDEWEB)

    Martoff, C.J.; Kaczanowicz, E. (Temple Univ., Philadelphia, PA (USA)); Neuhauser, B.J.; Lopez, E.; Zhang, Y. (San Francisco State Univ., CA (USA)); Ziemba, F.P. (Quantrad Corp. (USA))

    1991-03-01

    Detection of alpha particles at temperatures as low as 1.4 K was demonstrated using a specially fabricated Si diode. The diode was 475 mm{sup 2} by 0.280 mm thick, fabricated from high-purity silicon with degenerately doped contacts. This is an important step toward development of dual-mode (ionization plus phonon) silicon detectors for low energy radiation. (orig.).

  2. 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.

  3. 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. 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 ...

  5. 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, 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.

  6. 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

  7. Forming of nanocrystal silicon films by implantation of high dose of H+ in layers of silicon on isolator and following fast thermal annealing

    International Nuclear Information System (INIS)

    Tyschenko, I.E.; Popov, V.P.; Talochkin, A.B.; Gutakovskij, A.K.; Zhuravlev, K.S.

    2004-01-01

    Formation of nanocrystalline silicon films during rapid thermal annealing of the high-dose H + ion implanted silicon-on-insulator structures was studied. It was found, that Si nanocrystals had formed alter annealings at 300-400 deg C, their formation being strongly limited by the hydrogen content in silicon and also by the annealing time. It was supposed that the nucleation of crystalline phase occurred inside the silicon islands between micropores. It is conditioned by ordering Si-Si bonds as hydrogen atoms are leaving their sites in silicon network. No coalescence of micropores takes place during the rapid thermal annealing at the temperatures up to ∼ 900 deg C. Green-orange photoluminescence was observed on synthesized films at room temperature [ru

  8. 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.

  9. Silicon nanowire structures as high-sensitive pH-sensors

    International Nuclear Information System (INIS)

    Belostotskaya, S O; Chuyko, O V; Kuznetsov, A E; Kuznetsov, E V; Rybachek, E N

    2012-01-01

    Sensitive elements for pH-sensors created on silicon nanostructures were researched. Silicon nanostructures have been used as ion-sensitive field effect transistor (ISFET) for the measurement of solution pH. Silicon nanostructures have been fabricated by 'top-down' approach and have been studied as pH sensitive elements. Nanowires have the higher sensitivity. It was shown, that sensitive element, which is made of 'one-dimensional' silicon nanostructure have bigger pH-sensitivity as compared with 'two-dimensional' structure. Integrated element formed from two p- and n-type nanowire ISFET ('inverter') can be used as high sensitivity sensor for local relative change [H+] concentration in very small volume.

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

    International Nuclear Information System (INIS)

    Duraia, El-Shazly M.; Mansurov, Z.A.; Tokmolden, S.; Beall, Gary W.

    2010-01-01

    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 -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.

  11. 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.

  12. High performance SONOS flash memory with in-situ silicon nanocrystals embedded in silicon nitride charge trapping layer

    Science.gov (United States)

    Lim, Jae-Gab; Yang, Seung-Dong; Yun, Ho-Jin; Jung, Jun-Kyo; Park, Jung-Hyun; Lim, Chan; Cho, Gyu-seok; Park, Seong-gye; Huh, Chul; Lee, Hi-Deok; Lee, Ga-Won

    2018-02-01

    In this paper, SONOS-type flash memory device with highly improved charge-trapping efficiency is suggested by using silicon nanocrystals (Si-NCs) embedded in silicon nitride (SiNX) charge trapping layer. The Si-NCs were in-situ grown by PECVD without additional post annealing process. The fabricated device shows high program/erase speed and retention property which is suitable for multi-level cell (MLC) application. Excellent performance and reliability for MLC are demonstrated with large memory window of ∼8.5 V and superior retention characteristics of 7% charge loss for 10 years. High resolution transmission electron microscopy image confirms the Si-NC formation and the size is around 1-2 nm which can be verified again in X-ray photoelectron spectroscopy (XPS) where pure Si bonds increase. Besides, XPS analysis implies that more nitrogen atoms make stable bonds at the regular lattice point. Photoluminescence spectra results also illustrate that Si-NCs formation in SiNx is an effective method to form deep trap states.

  13. 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.

  14. High Aspect Ratio Sub-15 nm Silicon Trenches From Block Copolymer Templates

    Science.gov (United States)

    Gu, Xiaodan; Liu, Zuwei; Gunkel, Ilja; Olynick, Deirdre; Russell, Thomas; University of Massachusetts Amherst Collaboration; Oxford Instrument Collaboration; Lawrence Berkeley National Lab Collaboration

    2013-03-01

    High-aspect-ratio sub-15 nm silicon trenches are fabricated directly from plasma etching of a block copolymer (BCP) mask. Polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) 40k-b-18k was spin coated and solvent annealed to form cylindrical structures parallel to the silicon substrate. The BCP thin film was reconstructed by immersion in ethanol and then subjected to an oxygen and argon reactive ion etching to fabricate the polymer mask. A low temperature ion coupled plasma with sulfur hexafluoride and oxygen was used to pattern transfer block copolymer structure to silicon with high selectivity (8:1) and fidelity. The silicon pattern was characterized by scanning electron microscopy and grazing incidence x-ray scattering. We also demonstrated fabrication of silicon nano-holes using polystyrene-b-polyethylene oxide (PS-b-PEO) using same methodology described above for PS-b-P2VP. Finally, we show such silicon nano-strucutre serves as excellent nano-imprint master template to pattern various functional materials like poly 3-hexylthiophene (P3HT).

  15. Job stressors, personality and burnout in primary school teachers.

    Science.gov (United States)

    Kokkinos, Constantinos M

    2007-03-01

    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. Nevertheless, such studies are scarce with teacher samples. The present cross-sectional study sought to investigate the association between burnout, personality characteristics and job stressors in primary school teachers from Cyprus. The study also investigates the relative contribution of these variables on the three facets of burnout - emotional exhaustion, depersonalization and reduced personal accomplishment. A representative sample of 447 primary school teachers participated in the study. Teachers completed measures of burnout, personality and job stressors along with demographic and professional data. Surveys were delivered by courier to schools, and were distributed at faculty meetings. Results showed that both personality and work-related stressors were associated with burnout dimensions. Neuroticism was a common predictor of all dimensions of burnout although in personal accomplishment had a different direction. Managing student misbehaviour and time constraints were found to systematically predict dimensions of burnout. Teachers' individual characteristics as well as job related stressors should be taken into consideration when studying the burnout phenomenon. The fact that each dimension of the syndrome is predicted by different variables should not remain unnoticed especially when designing and implementing intervention programmes to reduce burnout in teachers.

  16. Metallurgical structures in a high uranium-silicon alloy

    International Nuclear Information System (INIS)

    Wyatt, B.S.; Berthiaume, L.C.; Conversi, J.L.

    1968-10-01

    The effects of fabrication and heat treatment variables on the structure of a uranium -- 3.96 wt% silicon alloy have been studied using optical microscopy, quantitative metallography and hardness determinations. It has been shown that an optimum temperature exists below the peritectoid temperature where the maximum amount of transformation to U 3 Si occurs in a given period of time. The time required to fully transform an as-cast alloy at this optimum temperature is affected by the size of the primary U 3 Si 2 dendrites. With a U 3 Si 2 particle size of <12 μm complete transformation can be achieved in four hours. (author)

  17. A Highly Responsive Silicon Nanowire/Amplifier MOSFET Hybrid Biosensor

    Science.gov (United States)

    2015-07-21

    Hybrid Biosensor Jieun Lee1,2, Jaeman Jang1, Bongsik Choi1, Jinsu Yoon1, Jee-Yeon Kim3, Yang-Kyu Choi3, Dong Myong Kim1, Dae Hwan Kim1 & Sung-Jin Choi1...This study demonstrates a hybrid biosensor comprised of a silicon nanowire (SiNW) integrated with an amplifier MOSFET to improve the current response...of field-effect-transistor (FET)-based biosensors . The hybrid biosensor is fabricated using conventional CMOS technology, which has the potential

  18. Burnout and the learning environment of anaesthetic trainees.

    Science.gov (United States)

    Castanelli, D J; Wickramaarachchi, S A; Wallis, S

    2017-11-01

    Burnout has a high prevalence among healthcare workers and is increasingly recognised as an environmental problem rather than reflecting a personal inability to cope with work stress. We distributed an electronic survey, which included the Maslach Burnout Inventory Health Services Survey and a previously validated learning environment instrument, to 281 Victorian anaesthetic trainees. The response rate was 50%. We found significantly raised rates of burnout in two of three subscales. Ninety-one respondents (67%) displayed evidence of burnout in at least one domain, with 67 (49%) reporting high emotional exhaustion and 57 (42%) reporting high depersonalisation. The clinical learning environment tool demonstrated a significant negative correlation with burnout (r=-0.56, P Burnout was significantly more common than when previously measured in Victoria in 2008 (62% versus 38%). Trainees rated examination preparation the most stressful aspect of the training program. There is a high prevalence of burnout among Victorian anaesthetic trainees. We have shown a significant correlation exists between the clinical learning environment measure and the presence of burnout. This correlation supports the development of interventions to improve the clinical learning environment, as a means to improve trainee wellbeing and address the high prevalence of burnout.

  19. Metallurgy of high-silicon steel parts produced using Selective Laser Melting

    International Nuclear Information System (INIS)

    Garibaldi, Michele; Ashcroft, Ian; Simonelli, Marco; Hague, Richard

    2016-01-01

    The metallurgy of high-silicon steel (6.9%wt.Si) processed using Selective Laser Melting (SLM) is presented for the first time in this study. High-silicon steel has great potential as a soft magnetic alloy, but its employment has been limited due to its poor workability. The effect of SLM-processing on the metallurgy of the alloy is investigated in this work using microscopy, X-Ray Diffraction (XRD) and Electron Backscatter Diffraction (EBSD). XRD analysis suggests that the SLM high-silicon steel is a single ferritic phase (solid solution), with no sign of phase ordering. This is expected to have beneficial effects on the material properties, since ordering has been shown to make silicon steels more brittle and electrically conductive. For near-fully dense samples, columnar grains with a high aspect ratio and oriented along the build direction are found. Most importantly, a <001> fibre-texture along the build direction can be changed into a cube-texture when the qualitative shape of the melt-pool is altered (from shallow to deep) by increasing the energy input of the scanning laser. This feature could potentially open the path to the manufacture of three-dimensional grain-oriented high-silicon steels for electromechanical applications.

  20. [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.

  1. High precision silicon piezo resistive SMART pressure sensor

    International Nuclear Information System (INIS)

    Brown, Rod

    2005-01-01

    Instruments for test and calibration require a pressure sensor that is precise and stable. Market forces also dictate a move away from single measurand test equipment and, certainly in the case of pressure, away from single range equipment. A pressure 'module' is required which excels in pressure measurement but is interchangble with sensors for other measurands. A communications interface for such a sensor has been specified. Instrument Digital Output Sensor (IDOS) that permits this interchanagability and allows the sensor to be inside or outside the measuring instrument. This paper covers the design and specification of a silicon diaphragm piezo resistive SMART sensor using this interface. A brief history of instrument sensors will be given to establish the background to this development. Design choices of the silicon doping, bridge energisation method, temperature sensing, signal conversion, data processing, compensation method, communications interface will be discussed. The physical format of the 'in-instrument' version will be shown and then extended to the packaging design for the external version. Test results will show the accuracy achieved exceeds the target of 0.01%FS over a range of temperatures

  2. High precision silicon piezo resistive SMART pressure sensor

    Science.gov (United States)

    Brown, Rod

    2005-01-01

    Instruments for test and calibration require a pressure sensor that is precise and stable. Market forces also dictate a move away from single measurand test equipment and, certainly in the case of pressure, away from single range equipment. A pressure `module' is required which excels in pressure measurement but is interchangble with sensors for other measurands. A communications interface for such a sensor has been specified. Instrument Digital Output Sensor (IDOS) that permits this interchanagability and allows the sensor to be inside or outside the measuring instrument. This paper covers the design and specification of a silicon diaphragm piezo resistive SMART sensor using this interface. A brief history of instrument sensors will be given to establish the background to this development. Design choices of the silicon doping, bridge energisation method, temperature sensing, signal conversion, data processing, compensation method, communications interface will be discussed. The physical format of the `in-instrument' version will be shown and then extended to the packaging design for the external version. Test results will show the accuracy achieved exceeds the target of 0.01%FS over a range of temperatures.

  3. Situational Factors Associated With Burnout Among Emergency Department Nurses.

    Science.gov (United States)

    Rozo, Jose Andres; Olson, DaiWai M; Thu, Hlaing Sue; Stutzman, Sonja E

    2017-06-01

    Emergency departments are high-stress environments for patients and clinicians. As part of the clinical team, nurses experience this stress daily and are subject to high levels of burnout, which has been shown to lead to hypertension, depression, and anxiety. Presence of these diseases may also contribute to burnout, creating a cycle of stress and illness. This prospective qualitative study used a phenomenological approach to better understand factors associated with burnout among emergency department nurses. Burnout manifests itself in multiple modes, can affect nurses' decisions to leave the profession, and must be addressed to mitigate the phenomenon.

  4. 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.

  5. Therapy of the burnout syndrome.

    Science.gov (United States)

    Korczak, Dieter; Wastian, Monika; Schneider, Michael

    2012-01-01

    The prevalence, diagnostics and therapy of the burnout syndrome are increasingly discussed in the public. The unclear definition and diagnostics 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 the therapy

  6. Burnout among Swedish school teachers - a cross-sectional analysis.

    Science.gov (United States)

    Arvidsson, Inger; Håkansson, Carita; Karlson, Björn; Björk, Jonas; Persson, Roger

    2016-08-18

    Teachers are at high risk of stress-related disorders. This study aimed to examine the occurrence of burnout in a sample of Swedish school-teachers, to test a combined measure of three burnout dimensions on the individual level, to characterize associations between burnout and factors encountered during work and leisure time, and to explore any differences between the genders. A questionnaire of occupational, sociodemographic and life-style factors was answered by 490 teachers in school years 4-9. Outcome measures were (a) the single burnout dimensions of exhaustion, cynicism and professional efficacy (Maslach Burnout Inventory-General Survey), and (b) a combined measure based on high or low values in the three dimensions. The combined measure was used to stratify the study population into four levels (0-3) of burnout. Multivariable Poisson regression was applied on level 2 + 3 vs. level 0 + 1, for variables that we considered as relevant risk factors for burn out. Half of the teachers reported low values in all three dimensions (level 0), whereas 15 were classified as having high burnout in at least two out of the three dimensions (level 2 + 3), and 4 % in all three dimensions (level 3). Almost all psychosocial factors were incrementally more unfavourably reported through the rising levels of burnout, and so were dissatisfaction with the computer workstation, pain, sleep problems and lack of personal recovery. There was no association between gender and rising levels of overall burnout (p > 0.30). Low self-efficacy, poor leadership, high job demands and teaching in higher grades were the variables most clearly associated with burnout in multivariable Poisson regression. Even if circa 50 % of the teachers appear do well with respect to burnout, the results points to the need of implementing multifaceted countermeasures that may serve to reduce burnout.

  7. How does burnout affect physician productivity? A systematic literature review

    OpenAIRE

    Dewa, Carolyn S; Loong, Desmond; Bonato, Sarah; Thanh, Nguyen Xuan; Jacobs, Philip

    2014-01-01

    Background Interest in the well-being of physicians has increased because of their contributions to the healthcare system quality. There is growing recognition that physicians are exposed to workplace factors that increase the risk of work stress. Long-term exposure to high work stress can result in burnout. Reports from around the world suggest that about one-third to one-half of physicians experience burnout. Understanding the outcomes associated with burnout is critical to understanding it...

  8. Analysis of heating effect on the process of high deposition rate microcrystalline silicon

    International Nuclear Information System (INIS)

    Xiao-Dan, Zhang; He, Zhang; Chang-Chun, Wei; Jian, Sun; Guo-Fu, Hou; Shao-Zhen, Xiong; Xin-Hua, Geng; Ying, Zhao

    2010-01-01

    A possible heating effect on the process of high deposition rate microcrystalline silicon has been studied. It includes the discharge time-accumulating heating effect, discharge power, inter-electrode distance, and total gas flow rate induced heating effect. It is found that the heating effects mentioned above are in some ways quite similar to and in other ways very different from each other. However, all of them will directly or indirectly cause the increase of the substrate surface temperature during the process of depositing microcrystalline silicon thin films, which will affect the properties of the materials with increasing time. This phenomenon is very serious for the high deposition rate of microcrystalline silicon thin films because of the high input power and the relatively small inter-electrode distance needed. Through analysis of the heating effects occurring in the process of depositing microcrystalline silicon, it is proposed that the discharge power and the heating temperature should be as low as possible, and the total gas flow rate and the inter-electrode distance should be suitable so that device-grade high quality deposition rate microcrystalline silicon thin films can be fabricated

  9. A high volume cost efficient production macrostructuring process. [for silicon solar cell surface treatment

    Science.gov (United States)

    Chitre, S. R.

    1978-01-01

    The paper presents an experimentally developed surface macro-structuring process suitable for high volume production of silicon solar cells. The process lends itself easily to automation for high throughput to meet low-cost solar array goals. The tetrahedron structure observed is 0.5 - 12 micron high. The surface has minimal pitting with virtually no or very few undeveloped areas across the surface. This process has been developed for (100) oriented as cut silicon. Chemi-etched, hydrophobic and lapped surfaces were successfully texturized. A cost analysis as per Samics is presented.

  10. Teacher Burnout: Causes and Projected Preventative and Curative Interventions

    Science.gov (United States)

    Warrad, Mohammad I.

    2012-01-01

    This mixed methods study examined how teachers at Valley High School internalize the phenomenon of teacher burnout. Teachers at Valley High School are suffering from teacher burnout on a daily basis with little to no support. The teachers at Valley High School were asked to participate in a survey, semi-structured interviews, and class…

  11. Nurse burnout and the working environment.

    Science.gov (United States)

    O'Mahony, Nuria

    2011-09-01

    This article examines levels of burnout experienced by emergency nurses and the characteristics of their work environment to determine if there is a relationship between the two. A literature review of recent articles on emergency nurses' burnout and contributing factors was undertaken. A quantitative study, in which nurses were asked to indicate the extent of their agreement with a series of statements on burnout and the working environment, was then undertaken, and the results were analysed to ascertain the extent to which the two topic are related. The results indicate that 52 per cent of nurses in an emergency department in Ireland experience high levels of emotional exhaustion and depersonalisation, which are significantly related to the nature of their work environment. Improvements to the environment and to education are required to reduce the risk of nurses developing burnout in the future.

  12. 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

  13. Professional burnout among studying nurses

    Directory of Open Access Journals (Sweden)

    Olga Bielan

    2011-09-01

    Full Text Available Burnout is a response to stress, the source of which is the situation at work. This phenomenon concerns mainly representatives of professions whose essence is to work with people, including doctors, nurses, paramedics and others; their close committed interactions with others constitute the core of professional activity and determine the success and development. Participants of the study were 281 students of extramural complementary nursing course at the University of Warmia and Mazury, mostly aged 40-60 years, employed in hospital wards and with employment contracts. In the study, the authors’ demographic questionnaire of structuralized interview and the MBI questionnaire, developed by Maslach and Jackson, in the Polish version by Pasikowski (2004, were used. The obtained results were statistically analysed. The performed analysis of burnout has confirmed that emotional exhaustion is associated with the length of employment, the number of days off and the number of institutions where nurses were employed. We did not observe, however, any correlation with these variables between depersonalisation and a sense of the lack of achievements. Furthermore, no dependence of the severity of the professional burnout symptoms on the surveyed groups’ age was found. It turned out that the persons working in shifts system felt much stronger depletion of emotion than nurses working in a daily system. It was also observed that nurses employed in hospitals felt much stronger symptoms in both areas of occupational burnout than those working in other institutions. Furthermore, it was not confirmed that the absence of the sense of achievement depended on where the respondents were employed. Taking into account the reference levels of the three dimensions of burnout acc. to MBI it was found out that most respondents were characterized by a low value within the emotional exhaustion and depersonalisation and a high value in terms of a sense of the lack of

  14. Statewide improvement approach to clinician burnout: Findings from the baseline year

    Directory of Open Access Journals (Sweden)

    Heather R. Britt

    2017-12-01

    We propose a socio-ecological framework for acting on burnout, using a data-driven quality improvement paradigm enabled by a statewide coalition, to ensure that continued efforts do not rest solely at the feet of individuals or systems. Despite high burnout levels, engagement and satisfaction with work are also high, suggesting there is still hope for stemming the tide of burnout.

  15. N-Type delta Doping of High-Purity Silicon Imaging Arrays

    Science.gov (United States)

    Blacksberg, Jordana; Hoenk, Michael; Nikzad, Shouleh

    2005-01-01

    A process for n-type (electron-donor) delta doping has shown promise as a means of modifying back-illuminated image detectors made from n-doped high-purity silicon to enable them to detect high-energy photons (ultraviolet and x-rays) and low-energy charged particles (electrons and ions). This process is applicable to imaging detectors of several types, including charge-coupled devices, hybrid devices, and complementary metal oxide/semiconductor detector arrays. Delta doping is so named because its density-vs.-depth characteristic is reminiscent of the Dirac delta function (impulse function): the dopant is highly concentrated in a very thin layer. Preferably, the dopant is concentrated in one or at most two atomic layers in a crystal plane and, therefore, delta doping is also known as atomic-plane doping. The use of doping to enable detection of high-energy photons and low-energy particles was reported in several prior NASA Tech Briefs articles. As described in more detail in those articles, the main benefit afforded by delta doping of a back-illuminated silicon detector is to eliminate a "dead" layer at the back surface of the silicon wherein high-energy photons and low-energy particles are absorbed without detection. An additional benefit is that the delta-doped layer can serve as a back-side electrical contact. Delta doping of p-type silicon detectors is well established. The development of the present process addresses concerns specific to the delta doping of high-purity silicon detectors, which are typically n-type. The present process involves relatively low temperatures, is fully compatible with other processes used to fabricate the detectors, and does not entail interruption of those processes. Indeed, this process can be the last stage in the fabrication of an imaging detector that has, in all other respects, already been fully processed, including metallized. This process includes molecular-beam epitaxy (MBE) for deposition of three layers, including

  16. 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.

  17. [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.

  18. Ultra-High Capacity Silicon Photonic Interconnects through Spatial Multiplexing

    Science.gov (United States)

    Chen, Christine P.

    The market for higher data rate communication is driving the semiconductor industry to develop new techniques of writing at smaller scales, while continuing to scale bandwidth at low power consumption. Silicon photonic (SiPh) devices offer a potential solution to the electronic interconnect bandwidth bottleneck. SiPh leverages the technology commensurate of decades of fabrication development with the unique functionality of next-generation optical interconnects. Finer fabrication techniques have allowed for manufacturing physical characteristics of waveguide structures that can support multiple modes in a single waveguide. By refining modal characteristics in photonic waveguide structures, through mode multiplexing with the asymmetric y-junction and microring resonator, higher aggregate data bandwidth is demonstrated via various combinations of spatial multiplexing, broadening applications supported by the integrated platform. The main contributions of this dissertation are summarized as follows. Experimental demonstrations of new forms of spatial multiplexing combined together exhibit feasibility of data transmission through mode-division multiplexing (MDM), mode-division and wavelength-division multiplexing (MDM-WDM), and mode-division and polarization-division multiplexing (MDM-PDM) through a C-band, Si photonic platform. Error-free operation through mode multiplexers and demultiplexers show how data can be viably scaled on multiple modes and with existing spatial domains simultaneously. Furthermore, we explore expanding device channel support from two to three arms. Finding that a slight mismatch in the third arm can increase crosstalk contributions considerably, especially when increasing data rate, we explore a methodical way to design the asymmetric y-junction device by considering its angles and multiplexer/demultiplexer arm width. By taking into consideration device fabrication variations, we turn towards optimizing device performance post

  19. Electrothermal Behavior of High-Frequency Silicon-On-Glass Transistors

    NARCIS (Netherlands)

    Nenadovic, N.

    2004-01-01

    In this thesis, research is focused on the investigation of electrothermal effects in high-speed silicon transistors. At high current levels the power dissipation in these devices can lead to heating of both the device itself and the adjacent devices. In advanced transistors these effects are

  20. Testing hadronic interaction models using a highly granular silicon-tungsten calorimeter

    Czech Academy of Sciences Publication Activity Database

    Bilki, B.; Repond, J.; Schlereth, J.; Cvach, Jaroslav; Gallus, Petr; Havránek, Miroslav; Janata, Milan; Kvasnička, Jiří; Lednický, Richard; Marčišovský, Michal; Polák, Ivo; Popule, Jiří; Tomášek, Lukáš; Tomášek, Michal; Růžička, Pavel; Šícho, Petr; Smolík, Jan; Vrba, Václav; Zálešák, Jaroslav

    2015-01-01

    Roč. 794, Sep (2015), s. 240-254 ISSN 0168-9002 R&D Projects: GA MŠk LG14033 Institutional support: RVO:68378271 Keywords : electromagnetic silicon tungsten calorimeter * highly granular detectors * hadronic showers * data and simulations Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.200, year: 2015

  1. Application of high energy accelerator to study of single event burn-out (SEB)

    Energy Technology Data Exchange (ETDEWEB)

    Hada, Takashi; Aoki, Shiro; Nakamura, Masao; Matsuda, Sumio [National Space Development Agency of Japan, Tokyo (Japan); Hirao, Toshio; Nashiyama, Isamu; Hirose, Takayuki; Ohira, Hideharu; Nagai, Yuki

    1996-12-01

    Hitherto, as nuclear fission fragments of 252-Cf, one of radioactive matters have been used for elucidation of single event mechanism, this method has a limit for analysis of power MOSFET with long charge collection region (generally, empty layer) and is difficult to form the experiment simulating the space environment, because of their wide LET (Linear Energy Transfer) range and of short flying distance of about 15 micrometer. As a result, some irradiation experiments using an accelerator capable of forming charged particle beam with long flying distance and single energy became essential to elucidate the SEB mechanism. In this paper, an experiment result of SEB phenomenon using high energy accelerator was reported. As a result, following items were found: (1) With increase of impressed charge, collected charge shows two peaks, and also increases, (2) commercial power MOSFET shows about 280 V in SEB resistance, and power MOSFET developed for the space use shows about 320 V, which is improved about 40 V for the commercial one, and so forth. (G.K.)

  2. 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.

  3. Radiation-hard silicon photonics for high energy physics and beyond

    CERN Multimedia

    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.

  4. High-dimensional quantum key distribution based on multicore fiber using silicon photonic integrated circuits

    DEFF Research Database (Denmark)

    Ding, Yunhong; Bacco, Davide; Dalgaard, Kjeld

    2017-01-01

    is intrinsically limited to 1 bit/photon. Here we propose and experimentally demonstrate, for the first time, a high-dimensional quantum key distribution protocol based on space division multiplexing in multicore fiber using silicon photonic integrated lightwave circuits. We successfully realized three mutually......-dimensional quantum states, and enables breaking the information efficiency limit of traditional quantum key distribution protocols. In addition, the silicon photonic circuits used in our work integrate variable optical attenuators, highly efficient multicore fiber couplers, and Mach-Zehnder interferometers, enabling...

  5. Occupational stress and burnout among Hong Kong dentists.

    Science.gov (United States)

    Choy, H B; Wong, M Cm

    2017-10-01

    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 (Poccupational stressors experienced by dentists in Hong Kong. In spite of this, a low proportion of dentists have a high level of overall burnout. There was a positive association between occupational stress and level of burnout.

  6. Family medicine residency training and burnout: a qualitative study

    Science.gov (United States)

    Rutherford, Kimberly; Oda, Joanna

    2014-01-01

    Background Almost three-quarters of family practice residents in British Columbia (BC) meet criteria for burnout. We sought to understand how burnout is perceived and experienced by family medicine residents, and to identify both contributory and protective factors for resident burnout. Method Two semi-structured focus groups were conducted with ten family practice residents from five distinct University of British Columbia training sites. Participants completed the Maslach Burnout Inventory (MBI). The data were analyzed using a thematic analysis approach. Results Seventy percent of the focus group participants met criteria for burnout using the MBI. The experience of burnout was described as physical and emotional exhaustion, loss of motivation, isolation from loved ones, and disillusionment with the medical profession. Contributory factors included high workload, burned-out colleagues, perceived undervaluing of family medicine, lack of autonomy, and inability to achieve work-life balance. Protective factors included strong role models in medicine, feeling that one’s work is valued and rotations in family medicine. Conclusions The high level of burnout in family medicine residents in BC is a multifactorial and complex phenomenon. Training programs and faculty should be aware of burnout risk factors and strive to implement changes to reduce burnout, including allowing residents increased control over scheduling, access to counseling services and training for resident mentors. PMID:26451218

  7. Family medicine residency training and burnout: a qualitative study.

    Science.gov (United States)

    Rutherford, Kimberly; Oda, Joanna

    2014-01-01

    Almost three-quarters of family practice residents in British Columbia (BC) meet criteria for burnout. We sought to understand how burnout is perceived and experienced by family medicine residents, and to identify both contributory and protective factors for resident burnout. Two semi-structured focus groups were conducted with ten family practice residents from five distinct University of British Columbia training sites. Participants completed the Maslach Burnout Inventory (MBI). The data were analyzed using a thematic analysis approach. Seventy percent of the focus group participants met criteria for burnout using the MBI. The experience of burnout was described as physical and emotional exhaustion, loss of motivation, isolation from loved ones, and disillusionment with the medical profession. Contributory factors included high workload, burned-out colleagues, perceived undervaluing of family medicine, lack of autonomy, and inability to achieve work-life balance. Protective factors included strong role models in medicine, feeling that one's work is valued and rotations in family medicine. The high level of burnout in family medicine residents in BC is a multifactorial and complex phenomenon. Training programs and faculty should be aware of burnout risk factors and strive to implement changes to reduce burnout, including allowing residents increased control over scheduling, access to counseling services and training for resident mentors.

  8. Personal risk factors associated with burnout among psychotherapists: A systematic review of the literature.

    Science.gov (United States)

    Simionato, Gabrielle K; Simpson, Susan

    2018-03-24

    Emotionally taxing job demands place psychotherapists at risk for burnout, often to the detriment of the therapist, clients, and the profession of psychotherapy (Maslach, 2007). The aim of the present systematic review was to (a) explore the levels of both burnout and job stress in psychotherapists, (b) identify tools used to measure work-related stress and burnout, and (c) identify personal risk factors for developing burnout among psychotherapists. Databases PsycINFO, Medline, EMBASE, ASSIA, and CINHAL were searched. Forty articles met inclusion criteria. Over half of sampled psychotherapists reported moderate-high levels of burnout, with the majority of results based on quantitative cross-sectional self-report surveys. Younger age, having less work experience, and being overinvolved in client problems were the most common personal risk factors for moderate-high levels of stress and burnout among psychotherapists. It appears that psychotherapists commonly experience some burnout, and personal factors influence burnout development. © 2018 Wiley Periodicals, Inc.

  9. 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%.

  10. Photo-induced current transient spectroscopy for high-resistivity neutron-transmutation-doped silicon

    International Nuclear Information System (INIS)

    Tokuda, Yutaka; Inoue, Yajiro; Usami, Akira

    1987-01-01

    Defects in high-resistivity neutron-transmutation-doped (NTD) silicon prior to annealing were studied by photo-induced current transient spectroscopy (PICTS). The thermal-neutron fluence was 9.5 x 10 17 cm -2 to give a resistivity of about 30 Ω after annealing, and the fast-neutron fluence was 9.5 x 10 16 cm -2 . Four traps with thermal emission activation energies of 0.15, 0.41. 0.47 and 0.50 eV were observed in NTD silicon. A trap with the thermal emission activation energy of 0.15 eV was considered to correspond to the divacancy. Although the clustered nature of the defects was observed, PICTS measurements suggest that the material state of high-resistivity NTD silicon is still crystalline and not amorphous. (author)

  11. 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

  12. 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

  13. 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

  14. Student Perspectives on Burnout

    Science.gov (United States)

    Mazerolle, Stephanie M.; Pagnotta, Kelly D.

    2011-01-01

    Context: While burnout has received a great deal of attention within the athletic training profession, there is little data on how it affects athletic training students (ATSs). Objective: To determine what factors influence burnout among ATSs enrolled in accredited athletic training education programs. Design and Setting: Basic, interpretive…

  15. Aerobic exercise training and burnout: a pilot study with male participants suffering from burnout

    Science.gov (United States)

    2013-01-01

    Background Occupational burnout is associated with severe negative health effects. While stress management programs proved to have a positive influence on the well-being of patients suffering from burnout, it remains unclear whether aerobic exercise alleviates burnout severity and other parameters related to occupational burnout. Therefore, the main purpose of this study was to pilot-test the potential outcomes of a 12-week exercise training to generate hypotheses for future larger scale studies. Methods The sample consisted of 12 male participants scoring high on the MBI emotional exhaustion and depersonalization subscales. The training program took place in a private fitness center with a 17.5 kcal/kg minimum requirement of weekly energy expenditure. Results The key findings are that increased exercise reduced overall perceived stress as well as symptoms of burnout and depression. The magnitude of the effects was large, revealing changes of substantial practical relevance. Additionally, profiles of mood states improved considerably after single exercise sessions with a marked shift towards an iceberg profile. Conclusion Among burnout patients, the findings provide preliminary evidence that exercise has the potential to reduce stress and prevent the development of a deeper depression. This has important health implications given that burnout is considered an antecedent of depressive disorders. Trial registration ClinicalTrials.gov Identifier: ISRNCT01575743 PMID:23497731

  16. A III-V nanowire channel on silicon for high-performance vertical transistors.

    Science.gov (United States)

    Tomioka, Katsuhiro; Yoshimura, Masatoshi; Fukui, Takashi

    2012-08-09

    Silicon transistors are expected to have new gate architectures, channel materials and switching mechanisms in ten years' time. The trend in transistor scaling has already led to a change in gate structure from two dimensions to three, used in fin field-effect transistors, to avoid problems inherent in miniaturization such as high off-state leakage current and the short-channel effect. At present, planar and fin architectures using III-V materials, specifically InGaAs, are being explored as alternative fast channels on silicon because of their high electron mobility and high-quality interface with gate dielectrics. The idea of surrounding-gate transistors, in which the gate is wrapped around a nanowire channel to provide the best possible electrostatic gate control, using InGaAs channels on silicon, however, has been less well investigated because of difficulties in integrating free-standing InGaAs nanostructures on silicon. Here we report the position-controlled growth of vertical InGaAs nanowires on silicon without any buffering technique and demonstrate surrounding-gate transistors using InGaAs nanowires and InGaAs/InP/InAlAs/InGaAs core-multishell nanowires as channels. Surrounding-gate transistors using core-multishell nanowire channels with a six-sided, high-electron-mobility transistor structure greatly enhance the on-state current and transconductance while keeping good gate controllability. These devices provide a route to making vertically oriented transistors for the next generation of field-effect transistors and may be useful as building blocks for wireless networks on silicon platforms.

  17. High Sensitivity and High Detection Specificity of Gold-Nanoparticle-Grafted Nanostructured Silicon Mass Spectrometry for Glucose Analysis.

    Science.gov (United States)

    Tsao, Chia-Wen; Yang, Zhi-Jie

    2015-10-14

    Desorption/ionization on silicon (DIOS) is a high-performance matrix-free mass spectrometry (MS) analysis method that involves using silicon nanostructures as a matrix for MS desorption/ionization. In this study, gold nanoparticles grafted onto a nanostructured silicon (AuNPs-nSi) surface were demonstrated as a DIOS-MS analysis approach with high sensitivity and high detection specificity for glucose detection. A glucose sample deposited on the AuNPs-nSi surface was directly catalyzed to negatively charged gluconic acid molecules on a single AuNPs-nSi chip for MS analysis. The AuNPs-nSi surface was fabricated using two electroless deposition steps and one electroless etching step. The effects of the electroless fabrication parameters on the glucose detection efficiency were evaluated. Practical application of AuNPs-nSi MS glucose analysis in urine samples was also demonstrated in this study.

  18. Reducing workplace burnout: the relative benefits of cardiovascular and resistance exercise

    OpenAIRE

    Bretland, Rachel Judith; Thorsteinsson, Einar Baldvin

    2015-01-01

    Objectives. The global burden of burnout cost is in excess of $300 billion annually. Locally, just under half of working Australians experience high levels of occupational burnout. Consequently, burnout interventions are paramount to organisational productivity. Exercise has the potential to provide a multilevel and cost effective burnout intervention. The current study aims to extend the literature by comparing cardiovascular with resistance exercise to assess their relative effectiveness ag...

  19. High-resolution ion-implanted silicon detectors

    International Nuclear Information System (INIS)

    von Borany, J.; Schmidt, B.

    1985-01-01

    An account is given of the properties of silicon detectors developed at the Central Institute of Nuclear Research of the Academy of Sciences of the German Democratic Republic (Rossendorf) and made by a special planar technology using ion implantation, anodic oxidation, thermal oxidation in an oxygen atmosphere containing HCl, and annealing by pulses of 10--20 msec duration. The resolution for α particles of 5.5 MeV energy was 11.2 keV (active area A 2 ). The detectors were characterized by a low intrinsic noise (< or =5 keV), so that they could be used for spectrometry of low-energy electrons (E/sub e/< or =250 keV). In a certain range of energies (E/sub x/ = 15--60 keV) it was possible to use these detectors for spectrometry of x rays at room temperature. Examples and results of applications of detectors in radiation chemistry (investigations of backscattering of particles and nuclear reaction spectroscopy) are given. The feasibility of annealing of radiation defects in such detectors after irradiation with a large dose of charged particles is considered

  20. Interrelations between Principals' Risk of Burnout Profiles and Proactive Self-Regulation Strategies

    Science.gov (United States)

    Tikkanen, Lotta; Pyhältö, Kirsi; Pietarinen, Janne; Soini, Tiina

    2017-01-01

    School leadership is a demanding job. Those involved in school leadership have shown to experience high levels of work stress that may, if prolonged, result in burnout. The purpose of this study was to examine school leaders' risks of burnout in terms of work stress and burnout symptoms, and their relationship with proactive self-regulation…

  1. 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…

  2. Rumination, Age, and Years of Experience: A Predictive Study of Burnout

    Science.gov (United States)

    McDuffy, Moriel S.

    2016-01-01

    This study used a non-experimental design to examine whether job satisfaction, rumination, age and years of experience predict burnout among human service workers serving high-risk populations. The study also used a stepwise regression to assess whether job satisfaction, rumination, age, or years of experience predict burnout equally. Burnout was…

  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. 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…

  5. 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…

  6. Burnout and Stress Among US Surgery Residents: Psychological Distress and Resilience.

    Science.gov (United States)

    Lebares, Carter C; Guvva, Ekaterina V; Ascher, Nancy L; O'Sullivan, Patricia S; Harris, Hobart W; Epel, Elissa S

    2018-01-01

    Burnout among physicians affects mental health, performance, and patient outcomes. Surgery residency is a high-risk time for burnout. We examined burnout and the psychological characteristics that can contribute to burnout vulnerability and resilience in a group of surgical trainees. An online survey was distributed in September 2016 to all ACGME-accredited general surgery programs. Burnout was assessed with an abbreviated Maslach Burnout Inventory. Stress, anxiety, depression, resilience, mindfulness, and alcohol use were assessed and analyzed for prevalence. Odds ratios (ORs) were used to determine the magnitude of presumed risk and resilience factors. Among 566 surgical residents who participated in the survey, prevalence of burnout was 69%, equally driven by emotional exhaustion and depersonalization. Perceived stress and distress symptoms (depression, suicidal ideation, and anxiety) were notably high across training levels, but improved during lab years. Higher burnout was associated with high stress (OR 7.8; p burnout (OR 0.24; p stress (OR 0.15; p burnout, severe stress, and distress symptoms are experienced throughout general surgery training, with some improvement during lab years. In this cross-sectional study, trainees with burnout and high stress were at increased risk for depression and suicidal ideation. Higher dispositional mindfulness was associated with lower risk of burnout, severe stress, and distress symptoms, supporting the potential of mindfulness training to promote resilience during surgery residency. Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  7. [Evolution of burnout and associated factors in primary care physicians].

    Science.gov (United States)

    Matía Cubillo, Angel Carlos; Cordero Guevara, José; Mediavilla Bravo, José Javier; Pereda Riguera, Maria José; González Castro, Maria Luisa; González Sanz, Ana

    2012-09-01

    To analyse the course of burnout and develop an explanatory model. Prospective cohort dynamics. SITE: All primary health care centres in Burgos. All physicians except medical emergencies, paediatrics and residents. Anonymous self-report questionnaire: Maslach Burnout Inventory (MBI) and related variables. An analysis was performed using the Student-t, X(2) test and logistic regression. The response rate was 47.76% in 2007, which was lower than that of 2005. There were significant differences between 2005 and 2007, for increases in the percentage of physicians who smoked, postgraduate training, residency, and those who believe that coordination with nursing and specialist care and institutional communication is appropriate. There was an increase in the prevalence of burnout by almost one point compared with 2005, a decrease in maximum burnout and emotional exhaustion (EC), and an increase in depersonalisation (DP) and personal accomplishment (RP). The incidence density of burnout was 1/113. 5 primary care physicians per year. The existence of burnout is associated with the use of chronic medication and inadequate coordination between nursing and EC, and also with the high workload. The increase in the prevalence found is consistent with the idea of burnout as a dynamic development and the theoretical model described. Stable and quality employment is one way to indirectly mitigate (by encouraging internal communication) professional burnout. In the multivariate analysis, the most critical variable in the onset of burnout is the inadequate coordination with nursing. Copyright © 2008 Elsevier España, S.L. All rights reserved.

  8. Resident burnout: evaluating the role of the learning environment.

    Science.gov (United States)

    van Vendeloo, Stefan N; Godderis, Lode; Brand, Paul L P; Verheyen, Kees C P M; Rowell, Suria A; Hoekstra, Harm

    2018-03-27

    Although burnout is viewed as a syndrome rooted in the working environment and organizational culture, the role of the learning environment in the development of resident burnout remains unclear. We aimed to evaluate the association between burnout and the learning environment in a cohort of Belgian residents. We conducted a cross-sectional online survey among residents in a large university hospital in Belgium. We used the Dutch version of the Maslach Burnout Inventory (UBOS-C) to assess burnout and the Dutch Residency Educational Climate Test (D-RECT) to assess the learning environment. A total of 236 residents (29 specialties) completed the survey (response rate 34.6%), of which 98 (41.5%) met standard criteria for burnout. After multivariate regression analysis adjusting for hours worked per week, quality of life and satisfaction with work-life balance, we found an inverse association between D-RECT scores and the risk of burnout (adjusted odds ratio; 0.47 for each point increase in D-RECT score; 95% CI, 0.23 - 0.95; p = 0.01). Resident burnout is highly prevalent in our cohort of Belgian residents. Our results suggest that the learning environment plays an important role in reducing the risk of burnout among residents.

  9. 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.

  10. Burnout in Customer Service Representatives

    Directory of Open Access Journals (Sweden)

    Tariq Jalees

    2008-09-01

    Full Text Available The purpose and aim of this research was to (1 identify the factors that contributes towards job burnout in sales service representative (2 What are the relationships of these factors (3 To empirically test the relationships of the determinants relating to burnout in customer service representatives. Based on literature survey six different variables related to burnout were identified. The variables were (1 Emotional exhaustion.(2 Reduced personal accomplishment.(3 Job induced tension.(4 Job satisfaction.(5 Workload (6 Job satisfaction.Each of the variables contained 3 sub-variables. Five different hypotheses were developed and tested through techniques such as Z-test, F-test and regression analysis. The questionnaire administered for the study contained 15 questions including personal data. The subject was Moblink company customers sales service representative in Karachi.The valid sample size was 98 drawn through multi-cluster technique. Techniques such as measure of dispersion and measure of central tendencies were used for analyzing the data. Regression, Z-test, and F-test were used for testing the developed hypothesis.According to the respondents’ opinions, the reduced personal accomplishment had a high rating with a mean of 3.75 and job induced tension has the lowest mean of 3.58. The standard deviation of respondents’ opinions was highest for dimension depersonalization and least for dimension work load. This indicates that there is a high polarization of the respondents’ opinions on the dimension depersonalization moral and least on the dimension work load.The Skew nesses for all the dimensions were in negative except the determinants emotional exhaustion and workload. This indicates that the majority of respondents’ opinions on all the dimensions were below the mean except in the case of emotional exhaustion and workload.Five hypotheses were developed and tested:a The hypothesis relating to low level of burnout in customers

  11. Direct writing of sub-wavelength ripples on silicon using femtosecond laser at high repetition rate

    International Nuclear Information System (INIS)

    Xie, Changxin; Li, Xiaohong; Liu, Kaijun; Zhu, Min; Qiu, Rong; Zhou, Qiang

    2016-01-01

    Graphical abstract: - Highlights: • The NSRs and DSRs are obtained on silicon surface. • With increasing direct writing speed, the NSRs suddenly changes and becomes the DSRs. • We develop a Sipe–Drude interference theory by considering the thermal excitation. - Abstract: The near sub-wavelength and deep sub-wavelength ripples on monocrystalline silicon were formed in air by using linearly polarized and high repetition rate femtosecond laser pulses (f = 76 MHz, λ = 800 nm, τ = 50 fs). The effects of laser pulse energy, direct writing speed and laser polarization on silicon surface morphology are studied. When the laser pulse energy is 2 nJ/pulse and the direct writing speed varies from 10 to 25 mm/s, the near sub-wavelength ripples (NSRs) with orientation perpendicular to the laser polarization are generated. While the direct writing speed reaches 30 mm/s, the direction of the obtained deep sub-wavelength ripples (DSRs) suddenly changes and becomes parallel to the laser polarization, rarely reported so far for femtosecond laser irradiation of silicon. Meanwhile, we extend the Sipe–Drude interference theory by considering the thermal excitation, and numerically calculate the efficacy factor for silicon irradiated by femtosecond laser pulses. The revised Sipe–Drude interference theoretical results show good agreement with the periods and orientations of sub-wavelength ripples.

  12. Use of Monocrystalline Silicon as Tool Material for Highly Accurate Blanking of Thin Metal Foils

    International Nuclear Information System (INIS)

    Hildering, Sven; Engel, Ulf; Merklein, Marion

    2011-01-01

    The trend towards miniaturisation of metallic mass production components combined with increased component functionality is still unbroken. Manufacturing these components by forming and blanking offers economical and ecological advantages combined with the needed accuracy. The complexity of producing tools with geometries below 50 μm by conventional manufacturing methods becomes disproportional higher. Expensive serial finishing operations are required to achieve an adequate surface roughness combined with accurate geometry details. A novel approach for producing such tools is the use of advanced etching technologies for monocrystalline silicon that are well-established in the microsystems technology. High-precision vertical geometries with a width down to 5 μm are possible. The present study shows a novel concept using this potential for the blanking of thin copper foils with monocrystallline silicon as a tool material. A self-contained machine-tool with compact outer dimensions was designed to avoid tensile stresses in the brittle silicon punch by an accurate, careful alignment of the punch, die and metal foil. A microscopic analysis of the monocrystalline silicon punch shows appropriate properties regarding flank angle, edge geometry and surface quality for the blanking process. Using a monocrystalline silicon punch with a width of 70 μm blanking experiments on as-rolled copper foils with a thickness of 20 μm demonstrate the general applicability of this material for micro production processes.

  13. Silicene Flowers: A Dual Stabilized Silicon Building Block for High-Performance Lithium Battery Anodes.

    Science.gov (United States)

    Zhang, Xinghao; Qiu, Xiongying; Kong, Debin; Zhou, Lu; Li, Zihao; Li, Xianglong; Zhi, Linjie

    2017-07-25

    Nanostructuring is a transformative way to improve the structure stability of high capacity silicon for lithium batteries. Yet, the interface instability issue remains and even propagates in the existing nanostructured silicon building blocks. Here we demonstrate an intrinsically dual stabilized silicon building block, namely silicene flowers, to simultaneously address the structure and interface stability issues. These original Si building blocks as lithium battery anodes exhibit extraordinary combined performance including high gravimetric capacity (2000 mAh g -1 at 800 mA g -1 ), high volumetric capacity (1799 mAh cm -3 ), remarkable rate capability (950 mAh g -1 at 8 A g -1 ), and excellent cycling stability (1100 mA h g -1 at 2000 mA g -1 over 600 cycles). Paired with a conventional cathode, the fabricated full cells deliver extraordinarily high specific energy and energy density (543 Wh kg ca -1 and 1257 Wh L ca -1 , respectively) based on the cathode and anode, which are 152% and 239% of their commercial counterparts using graphite anodes. Coupled with a simple, cost-effective, scalable synthesis approach, this silicon building block offers a horizon for the development of high-performance batteries.

  14. High efficiency high rate microcrystalline silicon thin-film solar cells deposited at plasma excitation frequencies larger than 100 MHz

    Czech Academy of Sciences Publication Activity Database

    Strobel, C.; Leszczynska, B.; Merkel, U.; Kuske, J.; Fischer, D.D.; Albert, M.; Holovský, Jakub; Michard, S.

    2015-01-01

    Roč. 143, Dec (2015), 347-353 ISSN 0927-0248 R&D Projects: GA MŠk 7E12029 EU Projects: European Commission(XE) 283501 - Fast Track Institutional support: RVO:68378271 Keywords : VHF * PECVD * microcrystalline silicon * solar cell * high rate * high efficiency Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.732, year: 2015

  15. Highly Manufacturable Deep (Sub-Millimeter) Etching Enabled High Aspect Ratio Complex Geometry Lego-Like Silicon Electronics.

    Science.gov (United States)

    Ghoneim, Mohamed Tarek; Hussain, Muhammad Mustafa

    2017-04-01

    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. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. 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.

  17. Time-Efficient High-Resolution Large-Area Nano-Patterning of Silicon Dioxide

    DEFF Research Database (Denmark)

    Lin, Li; Ou, Yiyu; Aagesen, Martin

    2017-01-01

    A nano-patterning approach on silicon dioxide (SiO2) material, which could be used for the selective growth of III-V nanowires in photovoltaic applications, is demonstrated. In this process, a silicon (Si) stamp with nanopillar structures was first fabricated using electron-beam lithography (EBL....... In addition, high time efficiency can be realized by one-spot electron-beam exposure in the EBL process combined with NIL for mass production. Furthermore, the one-spot exposure enables the scalability of the nanostructures for different application requirements by tuning only the exposure dose. The size...

  18. High-Q silicon-on-insulator slot photonic crystal cavity infiltrated by a liquid

    International Nuclear Information System (INIS)

    Caër, Charles; Le Roux, Xavier; Cassan, Eric

    2013-01-01

    We report the experimental realization of a high-Q slot photonic crystal cavity in Silicon-On-Insulator (SOI) configuration infiltrated by a liquid. Loaded Q-factor of 23 000 is measured at telecom wavelength. The intrinsic quality factor inferred from the transmission spectrum is higher than 200 000, which represents a record value for slot photonic crystal cavities on SOI, whereas the maximum of intensity of the cavity is roughly equal to 20% of the light transmitted in the waveguide. This result makes filled slot photonic crystal cavities very promising for silicon-based light emission and ultrafast nonlinear optics

  19. Extraction-spectrophotometric method for silicon determination in high-purity substances. 1. Silicon determination in tellurium

    Energy Technology Data Exchange (ETDEWEB)

    Shaburova, V P; Yudelevich, I G [AN SSSR, Novosibirsk (USSR). Inst. Neorganicheskoj Khimii

    1989-01-01

    The extraction-spectrophotometric method for silicon determination in tellurium based on extraction isolation of the base by tributyl phosphate from hydrochloride solutions and with addition of HNO/sub 3/ and spectrophotometric silicon determination using malachite green is developed. The method permits to determine 2x10/sup -1/-3x10/sup -4/ % Si.

  20. Electromechanical stability of electro-active silicone filled with high permittivity particles undergoing large deformation

    International Nuclear Information System (INIS)

    Liu, Liwu; Liu, Yanju; Zhang, Zhen; Leng, Jinsong; Li, Bo

    2010-01-01

    In this paper, an expression for the permittivity of electro-active silicone undergoing large deformation with high permittivity particles filled uniformly has been proposed. Two expressions are proposed for the permittivity, one based on experimental tests and the other based on the theory of composite material. By applying the thermodynamic model incorporating linear dielectric permittivity and nonlinear hyperelastic performance, the mechanical performance and electromechanical stability of the coupling system constituted by silicone filled with PMN–PT have been studied. The results show that the critical electric field decreases, namely the stability performance of the system declines when the content of PMN–PT c(v) increases and the electrostrictive coefficients increase. The results are beneficial for us to understand deeply the influence of the filled particle on the stability performance of silicone and to guide the design and manufacture of actuators and sensors based on dielectric elastomers

  1. Challenges and solutions for high-volume testing of silicon photonics

    Science.gov (United States)

    Polster, Robert; Dai, Liang Yuan; Oikonomou, Michail; Cheng, Qixiang; Rumley, Sebastien; Bergman, Keren

    2018-02-01

    The first generation of silicon photonic products is now commercially available. While silicon photonics possesses key economic advantages over classical photonic platforms, it has yet to become a commercial success because these advantages can be fully realized only when high-volume testing of silicon photonic devices is made possible. We discuss the costs, challenges, and solutions of photonic chip testing as reported in the recent research literature. We define and propose three underlying paradigms that should be considered when creating photonic test structures: Design for Fast Coupling, Design for Minimal Taps, and Design for Parallel Testing. We underline that a coherent test methodology must be established prior to the design of test structures, and demonstrate how an optimized methodology dramatically reduces the burden when designing for test, by reducing the needed complexity of test structures.

  2. [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 (p<0.001). Permanent staff have a greater degree of emotional exhaustion (p<0.002). Those who rated their leaders worst and least rated teamwork had more emotional exhaustion, depersonalization and higher level of burnout in general (p<0.001). The level of burnout among professionals is considerable, with differences existing between occupational categories. Teamwork and appreciating their leaders protect from burnout. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  3. HOLE-BLOCKING LAYERS FOR SILICON/ORGANIC HETEROJUNCTIONS: A NEW CLASS OF HIGH-EFFICIENCY LOW-COST PV

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, James [Princeton Univ., NJ (United States)

    2017-12-04

    This project is the first investigation of the use of thin titanium dioxide layers on silicon as a hole-blocking / electron-transparent selective contact to silicon. The work was motivated by the goal of a high-efficiency low-cost silicon-based solar cells that could be processed entirely at low temperature (300 Degree Celsius) or less, without requiring plasma-processing.

  4. 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.

  5. Radiation damage in silicon exposed to high-energy protons

    International Nuclear Information System (INIS)

    Davies, Gordon; Hayama, Shusaku; Murin, Leonid; Krause-Rehberg, Reinhard; Bondarenko, Vladimir; Sengupta, Asmita; Davia, Cinzia; Karpenko, Anna

    2006-01-01

    Photoluminescence, infrared absorption, positron annihilation, and deep-level transient spectroscopy (DLTS) have been used to investigate the radiation damage produced by 24 GeV/c protons in crystalline silicon. The irradiation doses and the concentrations of carbon and oxygen in the samples have been chosen to monitor the mobility of the damage products. Single vacancies (and self-interstitials) are introduced at the rate of ∼1 cm -1 , and divacancies at 0.5 cm -1 . Stable di-interstitials are formed when two self-interstitials are displaced in one damage event, and they are mobile at room temperature. In the initial stages of annealing the evolution of the point defects can be understood mainly in terms of trapping at the impurities. However, the positron signal shows that about two orders of magnitude more vacancies are produced by the protons than are detected in the point defects. Damage clusters exist, and are largely removed by annealing at 700 to 800 K, when there is an associated loss of broad band emission between 850 and 1000 meV. The well-known W center is generated by restructuring within clusters, with a range of activation energies of about 1.3 to 1.6 eV, reflecting the disordered nature of the clusters. Comparison of the formation of the X centers in oxygenated and oxygen-lean samples suggests that the J defect may be interstitial related rather than vacancy related. To a large extent, the damage and annealing behavior may be factorized into point defects (monitored by sharp-line optical spectra and DLTS) and cluster defects (monitored by positron annihilation and broadband luminescence). Taking this view to the limit, the generation rates for the point defects are as predicted by simply taking the damage generated by the Coulomb interaction of the protons and Si nuclei

  6. Performance of a silicon microstrip detector in a high radiation environment

    International Nuclear Information System (INIS)

    Mishra, C.S.; Brown, C.N.; Kapustinsky, J.; Leitch, M.J.; McGaughey, P.L.; Peng, J.C.; Sailor, W.; Holzscheiter, K.; Sadler, M.

    1990-01-01

    This paper reports on the performance of a silicon microstrip detector that has been studied in a high rate environment using electron, pion, and proton beams. The pulse height, time response, and leakage current have been studied as a function of particle fluence up to a total integrated flus of about 4 x 10 14 protons/cm 2

  7. 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.

  8. 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...

  9. Very high frequency plasma deposited amorphous/nanocrystalline silicon tandem solar cells on flexible substrates

    NARCIS (Netherlands)

    Liu, Y.|info:eu-repo/dai/nl/304831743

    2010-01-01

    The work in this thesis is to develop high quality intrinsic layers (especially nc-Si:H) for micromorph silicon tandem solar cells/modules on plastic substrates following the substrate transfer method or knows as the Helianthos procedure. Two objectives are covered in this thesis: (1) preliminary

  10. Linear and nonlinear characterization of low-stress high-confinement silicon-rich nitride waveguides.

    Science.gov (United States)

    Krückel, Clemens J; Fülöp, Attila; Klintberg, Thomas; Bengtsson, Jörgen; Andrekson, Peter A; Torres-Company, Víctor

    2015-10-05

    In this paper we introduce a low-stress silicon enriched nitride platform that has potential for nonlinear and highly integrated optics. The manufacturing process of this platform is CMOS compatible and the increased silicon content allows tensile stress reduction and crack free layer growth of 700 nm. Additional benefits of the silicon enriched nitride is a measured nonlinear Kerr coefficient n(2) of 1.4·10(-18) m(2)/W (5 times higher than stoichiometric silicon nitride) and a refractive index of 2.1 at 1550 nm that enables high optical field confinement allowing high intensity nonlinear optics and light guidance even with small bending radii. We analyze the waveguide loss (∼1 dB/cm) in a spectrally resolved fashion and include scattering loss simulations based on waveguide surface roughness measurements. Detailed simulations show the possibility for fine dispersion and nonlinear engineering. In nonlinear experiments we present continuous-wave wavelength conversion and demonstrate that the material does not show nonlinear absorption effects. Finally, we demonstrate microfabrication of resonators with high Q-factors (∼10(5)).

  11. Thin-Film layers with Interfaces that reduce RF Losses on High-Resistivity Silicon Substrates

    NARCIS (Netherlands)

    Evseev, S. B.; Milosavljevic, S.; Nanver, L. K.

    2017-01-01

    Radio-Frequency (RF) losses on High-Resistivity Silicon (HRS) substrates were studied for several different surface passivation layers comprising thin-films of SiC, SiN and SiO2 In many combinations, losses from conductive surface channels were reduced and increasing the number of interfaces between

  12. Compact high-efficiency vortex beam emitter based on a silicon photonics micro-ring

    DEFF Research Database (Denmark)

    Li, Shimao; Ding, Yunhong; Guan, Xiaowei

    2018-01-01

    Photonic integrated devices that emit vortex beam carrying orbital angular momentum are becoming key components for multiple applications. Here we propose and demonstrate a high-efficiency vortex beam emitter based on a silicon micro-ring resonator integrated with a metal mirror. Such a compact...

  13. 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.

  14. Guidelines for etching silicon MEMS structures using fluorine high-density plasmas at cryogenic temperatures

    NARCIS (Netherlands)

    de Boer, Meint J.; Gardeniers, Johannes G.E.; Jansen, Henricus V.; Gilde, M.J.; Roelofs, Gerard; Sasserath, Jay N.; Elwenspoek, Michael Curt

    This paper presents guidelines for the deep reactive ion etching (DRIE) of silicon MEMS structures, employing SF6/O2-based high-density plasmas at cryogenic temperatures. Procedures of how to tune the equipment for optimal results with respect to etch rate and profile control are described. Profile

  15. Signal generation in highly irradiated silicon microstrip detectors for the ATLAS experiment

    International Nuclear Information System (INIS)

    Ruggiero, Gennaro

    2003-01-01

    Silicon detectors are the most diffused tracking devices in High Energy Physics (HEP). The reason of such success can be found in the characteristics of the material together with the existing advanced technology for the fabrication of these devices. Nevertheless in many modem HEP experiments the observation of vary rare events require data taking at high luminosity with a consequent extremely intense hadron radiation field that damages the silicon and degrades the performance of these devices. In this thesis work a detailed study of the signal generation in microstrip detectors has been produced with a special care for the ATLAS semiconductor tracker geometry. This has required a development of an appropriate setup to perform measurements with Transient Current/ Charge Technique. This has allowed studying the evolution of the signal in several microstrips detector samples irradiated at fluences covering the range expected in the ATLAS Semiconductor Tracker. For a better understanding of these measurements a powerful software package that simulates the signal generation in these devices has been developed. Moreover in this thesis it has been also shown that the degradation due to radiation in silicon detectors can be strongly reduced if the data taking is done with detectors operated at 130 K. This makes low temperature operation that benefits of the recovery of the charge collection efficiency in highly irradiated silicon detectors (also known as Lazarus effect) an optimal option for future high luminosity experiments. (author)

  16. 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.

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

    International Nuclear Information System (INIS)

    Kusano, Aaron S.; Thomas, Charles R.; Bonner, James A.; DeWeese, Theodore L.; Formenti, Silvia C.; Hahn, Stephen M.; Lawrence, Theodore S.; Mittal, Bharat B.

    2014-01-01

    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

  18. 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

  19. Burnout among physicians | Romani | Libyan Journal of Medicine

    African Journals Online (AJOL)

    Burnout is a common syndrome seen in healthcare workers, particularly physicians who are exposed to a high level of stress at work; it includes emotional exhaustion, depersonalization, and low personal accomplishment. Burnout among physicians has garnered significant attention because of the negative impact it ...

  20. 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…

  1. Burnout among paramedic students at a university in Johannesburg ...

    African Journals Online (AJOL)

    Background. Burnout has been studied in several emergency medical services contexts and has been found to be high compared with that found in other health professions. Although burnout among students has been described in several healthcare disciplines, this has not been done in the field of prehospital emergency ...

  2. 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.

  3. Single-crystal silicon trench etching for fabrication of highly integrated circuits

    Science.gov (United States)

    Engelhardt, Manfred

    1991-03-01

    The development of single crystal silicon trench etching for fabrication of memory cells in 4 16 and 64Mbit DRAMs is reviewed in this paper. A variety of both etch tools and process gases used for the process development is discussed since both equipment and etch chemistry had to be improved and changed respectively to meet the increasing requirements for high fidelity pattern transfer with increasing degree of integration. In additon to DRAM cell structures etch results for deep trench isolation in advanced bipolar ICs and ASICs are presented for these applications grooves were etched into silicon through a highly doped buried layer and at the borderline of adjacent p- and n-well areas respectively. Shallow trench etching of large and small exposed areas with identical etch rates is presented as an approach to replace standard LOCOS isolation by an advanced isolation technique. The etch profiles were investigated with SEM TEM and AES to get information on contathination and damage levels and on the mechanism leading to anisotropy in the dry etch process. Thermal wave measurements were performed on processed single crystal silicon substrates for a fast evaluation of the process with respect to plasma-induced substrate degradation. This useful technique allows an optimization ofthe etch process regarding high electrical performance of the fully processed memory chip. The benefits of the use of magnetic fields for the development of innovative single crystal silicon dry

  4. Corrugation Architecture Enabled Ultraflexible Wafer-Scale High-Efficiency Monocrystalline Silicon Solar Cell

    KAUST Repository

    Bahabry, Rabab R.

    2018-01-02

    Advanced classes of modern application require new generation of versatile solar cells showcasing extreme mechanical resilience, large-scale, low cost, and excellent power conversion efficiency. Conventional crystalline silicon-based solar cells offer one of the most highly efficient power sources, but a key challenge remains to attain mechanical resilience while preserving electrical performance. A complementary metal oxide semiconductor-based integration strategy where corrugation architecture enables ultraflexible and low-cost solar cell modules from bulk monocrystalline large-scale (127 × 127 cm) silicon solar wafers with a 17% power conversion efficiency. This periodic corrugated array benefits from an interchangeable solar cell segmentation scheme which preserves the active silicon thickness of 240 μm and achieves flexibility via interdigitated back contacts. These cells can reversibly withstand high mechanical stress and can be deformed to zigzag and bifacial modules. These corrugation silicon-based solar cells offer ultraflexibility with high stability over 1000 bending cycles including convex and concave bending to broaden the application spectrum. Finally, the smallest bending radius of curvature lower than 140 μm of the back contacts is shown that carries the solar cells segments.

  5. Corrugation Architecture Enabled Ultraflexible Wafer-Scale High-Efficiency Monocrystalline Silicon Solar Cell

    KAUST Repository

    Bahabry, Rabab R.; Kutbee, Arwa T.; Khan, Sherjeel M.; Sepulveda, Adrian C.; Wicaksono, Irmandy; Nour, Maha A.; Wehbe, Nimer; Almislem, Amani Saleh Saad; Ghoneim, Mohamed T.; Sevilla, Galo T.; Syed, Ahad; Shaikh, Sohail F.; Hussain, Muhammad Mustafa

    2018-01-01

    Advanced classes of modern application require new generation of versatile solar cells showcasing extreme mechanical resilience, large-scale, low cost, and excellent power conversion efficiency. Conventional crystalline silicon-based solar cells offer one of the most highly efficient power sources, but a key challenge remains to attain mechanical resilience while preserving electrical performance. A complementary metal oxide semiconductor-based integration strategy where corrugation architecture enables ultraflexible and low-cost solar cell modules from bulk monocrystalline large-scale (127 × 127 cm) silicon solar wafers with a 17% power conversion efficiency. This periodic corrugated array benefits from an interchangeable solar cell segmentation scheme which preserves the active silicon thickness of 240 μm and achieves flexibility via interdigitated back contacts. These cells can reversibly withstand high mechanical stress and can be deformed to zigzag and bifacial modules. These corrugation silicon-based solar cells offer ultraflexibility with high stability over 1000 bending cycles including convex and concave bending to broaden the application spectrum. Finally, the smallest bending radius of curvature lower than 140 μm of the back contacts is shown that carries the solar cells segments.

  6. Changes in myopia with low-Dk hydrogel and high-Dk silicone hydrogel extended wear.

    Science.gov (United States)

    Jalbert, Isabelle; Stretton, Serina; Naduvilath, Thomas; Holden, Brien; Keay, Lisa; Sweeney, Deborah

    2004-08-01

    This study compared changes in myopia between wearers of high-oxygen permeability (Dk) silicone hydrogel lenses and low-Dk hydrogel lenses after 1 year of extended wear (EW). Ninety-two adult subjects were randomly assigned to a lens type. Subjective refraction and autokeratometry were performed at baseline and at 6 and 12 months. After 6 months of EW, myopia (spherical equivalent) regressed by 0.18 +/- 0.33 D (p Dk silicone hydrogel group and progressed by -0.23 +/- 0.36 D (p Dk hydrogel group. There were no further changes after 12 months. Previous lens wear history, baseline refractive error, and age and gender did not have an impact on the change in myopia, and only 35% of the variation could be accounted for by changes in corneal curvature and lens type. Soft contact lens type significantly affects the direction of change in myopia during EW. We hypothesize that these changes are driven by pressure-related redistribution of corneal tissue in high-Dk silicone hydrogel lens wearers and by hypoxia-associated corneal thinning in low-Dk hydrogel wearers. More long-term studies are required to confirm whether the effects of high-Dk silicone hydrogel lens wear on myopia are permanent.

  7. High-performance macroporous bulk silicon anodes synthesized by template-free chemical etching

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Byoung Man; Lee, Jung-In; Kim, Hyunjung; Cho, Jaephil; Park, Soojin [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology (UNIST), Ulsan (Korea, Republic of)

    2012-07-15

    Three-dimensional porous silicon particles can be produced via the combination of a galvanic displacement reaction and a metal-assisted chemical etching process. This simple synthetic route can be applied to make high-performance anode materials, including high specific capacity, stable cycling retention, and high rate capability, in lithium-ion batteries. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. High-field Overhauser dynamic nuclear polarization in silicon below the metal-insulator transition.

    Science.gov (United States)

    Dementyev, Anatoly E; Cory, David G; Ramanathan, Chandrasekhar

    2011-04-21

    Single crystal silicon is an excellent system to explore dynamic nuclear polarization (DNP), as it exhibits a continuum of properties from metallic to insulating as a function of doping concentration and temperature. At low doping concentrations DNP has been observed to occur via the solid effect, while at very high-doping concentrations an Overhauser mechanism is responsible. Here we report the hyperpolarization of (29)Si in n-doped silicon crystals, with doping concentrations in the range of (1-3) × 10(17) cm(-3). In this regime exchange interactions between donors become extremely important. The sign of the enhancement in our experiments and its frequency dependence suggest that the (29)Si spins are directly polarized by donor electrons via an Overhauser mechanism within exchange-coupled donor clusters. The exchange interaction between donors only needs to be larger than the silicon hyperfine interaction (typically much smaller than the donor hyperfine coupling) to enable this Overhauser mechanism. Nuclear polarization enhancement is observed for a range of donor clusters in which the exchange energy is comparable to the donor hyperfine interaction. The DNP dynamics are characterized by a single exponential time constant that depends on the microwave power, indicating that the Overhauser mechanism is a rate-limiting step. Since only about 2% of the silicon nuclei are located within 1 Bohr radius of the donor electron, nuclear spin diffusion is important in transferring the polarization to all the spins. However, the spin-diffusion time is much shorter than the Overhauser time due to the relatively weak silicon hyperfine coupling strength. In a 2.35 T magnetic field at 1.1 K, we observed a DNP enhancement of 244 ± 84 resulting in a silicon polarization of 10.4 ± 3.4% following 2 h of microwave irradiation.

  9. Microstructure and wear behavior of austempered high carbon high silicon steel

    Directory of Open Access Journals (Sweden)

    Acharya Palaksha

    2018-01-01

    Full Text Available In the present investigation, the influence of austempering temperature and time on the microstructure and dry sliding wear behavior of high silicon steel was studied. The test specimens were initially austenitised at 900°C for 30 minutes, thereafter austempered at various temperatures 280°C, 360°C and 400°C, for varying duration from 30 to 120 minutes. These samples after austempering heat treatment were subsequently air cooled to room temperature, to generate typical ausferritic microstructures and then correlated with the wear property. The test outcomes demonstrate the slight increase in specific wear rate with increase in both austempering temperature and time. Specific wear rate was found to be minimum at an austempering temperature of 280°C, that exhibits lower bainite microstructure with high hardness, on the other hand specific wear rate was found to be slightly high at increased austempering temperatures at 360°C and 400°C, due to the upper bainite structure that offered lower hardness to the matrix. The sample austempered at 280°C for 30 minutes offered superior wear resistance when compared to other austempering conditions, mainly due to the presence of fine acicular bainitic ferrite along with stabilized retained austenite and also some martensite in the microstructure.

  10. Burnout em Cuidadores Formais

    OpenAIRE

    Silva, Juliana Marisa Fernandes

    2016-01-01

    Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para a obtenção do grau de Mestre em Psicologia, ramo de Psicologia Clínica e da Saúde Este estudo é sobre a Síndrome de Burnout e teve como objetivo geral compreender se o Burnout está presente nos cuidadores formais da Santa Casa da Misericórdia de Castelo de Paiva e quais as variáveis socioprofissionais que poderão exercer influência no seu aparecimento. Pretendeu-se avaliar o Burnout dos cuidadores a tr...

  11. Silicon coating treatment to improve high temperature corrosion resistance of 9%Cr steels

    International Nuclear Information System (INIS)

    Hill, M.P.

    1989-01-01

    A silicon coating process is described which confers good protection on 9%Cr steels and alloys in CO 2 based atmospheres at high temperatures and pressures. The coatings are formed by decomposition of silane at temperatures above 720 K. Protective layers are typically up to 1 μm thick. The optimum coating conditions are discussed. The chemical state of the coatings has been investigated by X-ray photoelectron spectroscopy and has demonstrated the importance of avoiding silicon oxide formation during processing. Corrosion testing has been carried out for extended periods, up to 20 000 h, at temperatures between 753 and 853 K, in a simulated advanced gas cooled reactor gas at 4 MPa pressure. Benefit factors of up to 60 times have been measured for 9%Cr steels. Even higher values have been measured for 9Cr-Fe binary alloy on which a 1 μm coating was sufficient to eliminate significant oxidation over 19 000 h except at the specimen edges. The mechanism of protection is discussed. It is suggested that a silicon surface coating for protecting steels from high temperature corrosion has some advantages over adding silicon to the bulk metal. (author)

  12. 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.

  13. High Surface Area of Porous Silicon Drives Desorption of Intact Molecules

    Science.gov (United States)

    Northen, Trent R.; Woo, Hin-Koon; Northen, Michael T.; Nordström, Anders; Uritboonthail, Winnie; Turner, Kimberly L.; Siuzdak, Gary

    2007-01-01

    The surface structure of porous silicon used in desorption/ionization on porous silicon (DIOS) mass analysis is known to play a primary role in the desorption/ionization (D/I) process. In this study, mass spectrometry and scanning electron microscopy (SEM) are used to examine the correlation between intact ion generation with surface ablation, and surface morphology. The DIOS process is found to be highly laser energy dependent and correlates directly with the appearance of surface ions (Sin+ and OSiH+). A threshold laser energy for DIOS is observed (10 mJ/cm2), which supports that DIOS is driven by surface restructuring and is not a strictly thermal process. In addition, three DIOS regimes are observed which correspond to surface restructuring and melting. These results suggest that higher surface area silicon substrates may enhance DIOS performance. A recent example which fits into this mechanism is silicon nanowires surface which have a high surface energy and concomitantly requires lower laser energy for analyte desorpton. PMID:17881245

  14. 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.

  15. Incivility from patients and their families: can organisational justice protect nurses from burnout?

    Science.gov (United States)

    Campana, Kristie L; Hammoud, Sammira

    2015-09-01

    To determine whether interpersonal and informational justice influence the association between daily experiences of incivility and burnout among nurses. Research has suggested that incivility is a concern for managers. Nurses regularly experience incivility, particularly from their patients and patients' families. Incivility, in turn, can increase symptoms of burnout. Seventy-five nurses provided data on interpersonal and informational justice within their organisation. During five working days, nurses completed a twice-daily survey assessing incivility and burnout. Hierarchical linear modelling analyses examined the main effects and interaction effects of the three variables on burnout. Incivility was positively associated with burnout. In addition, interpersonal justice strengthened the incivility-burnout relationship. Informational justice did not significantly affect the incivility-burnout relationship. Incivility is associated with more burnout. The work environment also influences burnout; when organisations provide informational justice, nurses experience less burnout. In organisations where interpersonal justice is high, nurses are more likely to experience burnout. Nursing managers can help employees by ensuring that management's decisions are transparent. In addition, managers should be aware that in organisations with higher interpersonal justice, nurses might be more likely to experience symptoms of burnout as a result of incivility from patients and their families. © 2013 John Wiley & Sons Ltd.

  16. Burnout in Orthopaedic Surgeons: A Challenge for Leaders, Learners, and Colleagues: AOA Critical Issues.

    Science.gov (United States)

    Ames, S Elizabeth; Cowan, James B; Kenter, Keith; Emery, Sanford; Halsey, David

    2017-07-19

    Burnout, depression, suicidal ideation, and dissatisfaction with work-life balance have been reported in all medical specialties and at all stages of medical education and practice experience. Burnout consists of progressive emotional, attitudinal, and physical exhaustion. Physicians with burnout may treat patients as objects and feel emotionally depleted. Burnout is characterized by a loss of enthusiasm for work (emotional exhaustion), feelings of cynicism (depersonalization), and a low sense of personal accomplishment. The most complete study of emotional burnout among different medical specialties demonstrated that orthopaedic surgery is one of the specialties with the highest burnout rate. Qualitative descriptive studies are available. There was a 45.8% burnout rate among physicians in the U.S. in 2012, and a 2014 update suggested even higher rates. Burnout has a correlation with medical education. Burnout rates are similar to those in the general population when medical students enter school, and increase steadily through medical education prior to residency. Burnout rates in residents are high, reported to be between 41% and 74% across multiple specialties. This impacts our young physician workforce in orthopaedics. The purpose of this review is to provide the available information that characterizes burnout and addresses the issues inherent to preventing burnout, and to build awareness in orthopaedic surgeons. Wellness "goes beyond merely the absence of distress and includes being challenged, thriving, and achieving success in various aspects of personal and professional life." The challenge for the orthopaedic community is to develop interventions and strategies that are personalized to the individuals in this specialty.

  17. Study of transient burnout under flow reduction condition

    International Nuclear Information System (INIS)

    Iwamura, Takamichi

    1986-09-01

    Transient burnout characteristics of a fuel rod under a rapid flow reduction condition of a light water reactor were experimentally and analytically studied. The test sections were uniformly heated vertical tube and annulus with the heated length of 800 mm. Test pressures ranged 0.5 ∼ 3.9 MPa, heat fluxes 2,160 ∼ 3,860 KW/m 2 , and flow reduction rates 0.44 ∼ 770 %/s. The local flow condition during flow reduction transients were calculated with a separate flow model. The two-fluid/three-field thermal-hydraulic code, COBRA/TRAC, was also used to investigate the liquid film behavior on the heated surface. The major results obtained in the present study are as follows: The onset of burnout under a rapid flow reduction condition was caused by a liquid film dryout on the heated surface. With increasing flow reduction rate beyond a threshold, the burnout mass velocity at the inlet became lower than the steady-state burnout mass velocity. This is explained by the fact that the vapor flow rate continues to increase due to the delay of boiling boundary movement and the resultant high vapor velocity sustains the liquid film flow after the inlet flow rate reaches the steady-state burnout flow rate. The ratio of inlet burnout mass velocities between flow reduction transient and steady-state became smaller with increasing system pressure because of the lower vapor velocity due to the lower vapor specific volume. Flow reduction burnout occurred when the outlet quality agreed with the steady-state burnout quality within 10 %, suggesting that the local condition burnout model can be used for flow reduction transients. Based on this model, a method to predict the time to burnout under a flow reduction condition in a uniformly heated tube was developed. The calculated times to burnout agreed well with some experimental results obtained by the Author, Cumo et al., and Moxon et al. (author)

  18. Burnout in the intensive care unit professionals: A systematic review.

    Science.gov (United States)

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

    2016-12-01

    Burnout has been described as a prolonged response to chronic emotional and interpersonal stress on the job that is often the result of a period of expending excessive effort at work while having too little recovery time. Healthcare workers who work in a stressful medical environment, especially in an intensive care unit (ICU), may be particularly susceptible to burnout. In healthcare workers, burnout may affect their well-being and the quality of professional care they provide and can, therefore, be detrimental to patient safety. The objectives of this study were: to determine the prevalence of burnout in the ICU setting; and to identify factors associated with burnout in ICU professionals. The original articles for observational studies were retrieved from PubMed, MEDLINE, and Web of Science in June 2016 using the following MeSH terms: "burnout" and "intensive care unit". Articles that were published in English between January 1996 and June 2016 were eligible for inclusion. Two reviewers evaluated the abstracts identified using our search criteria prior to full text review. To be included in the final analysis, studies were required to have employed an observational study design and examined the associations between any risk factors and burnout in the ICU setting. Overall, 203 full text articles were identified in the electronic databases after the exclusion of duplicate articles. After the initial review, 25 studies fulfilled the inclusion criteria. The prevalence of burnout in ICU professionals in the included studies ranged from 6% to 47%. The following factors were reported to be associated with burnout: age, sex, marital status, personality traits, work experience in an ICU, work environment, workload and shift work, ethical issues, and end-of-life decision-making. The impact of the identified factors on burnout remains poorly understood. Nevertheless, this review presents important information, suggesting that ICU professionals may suffer from a high level

  19. Conformal coating of amorphous silicon and germanium by high pressure chemical vapor deposition for photovoltaic fabrics

    Science.gov (United States)

    Ji, Xiaoyu; Cheng, Hiu Yan; Grede, Alex J.; Molina, Alex; Talreja, Disha; Mohney, Suzanne E.; Giebink, Noel C.; Badding, John V.; Gopalan, Venkatraman

    2018-04-01

    Conformally coating textured, high surface area substrates with high quality semiconductors is challenging. Here, we show that a high pressure chemical vapor deposition process can be employed to conformally coat the individual fibers of several types of flexible fabrics (cotton, carbon, steel) with electronically or optoelectronically active materials. The high pressure (˜30 MPa) significantly increases the deposition rate at low temperatures. As a result, it becomes possible to deposit technologically important hydrogenated amorphous silicon (a-Si:H) from silane by a simple and very practical pyrolysis process without the use of plasma, photochemical, hot-wire, or other forms of activation. By confining gas phase reactions in microscale reactors, we show that the formation of undesired particles is inhibited within the microscale spaces between the individual wires in the fabric structures. Such a conformal coating approach enables the direct fabrication of hydrogenated amorphous silicon-based Schottky junction devices on a stainless steel fabric functioning as a solar fabric.

  20. High performance multilayered nano-crystalline silicon/silicon-oxide light-emitting diodes on glass substrates

    Energy Technology Data Exchange (ETDEWEB)

    Darbari, S; Shahmohammadi, M; Mortazavi, M; Mohajerzadeh, S [Thin Film and Nano-Electronic Laboratory, School of ECE, University of Tehran, Tehran (Iran, Islamic Republic of); Abdi, Y [Nano-Physics Research Laboratory, Department of Physics, University of Tehran, Tehran (Iran, Islamic Republic of); Robertson, M; Morrison, T, E-mail: mohajer@ut.ac.ir [Department of Physics, Acadia University, Wolfville, NS (Canada)

    2011-09-16

    A low-temperature hydrogenation-assisted sequential deposition and crystallization technique is reported for the preparation of nano-scale silicon quantum dots suitable for light-emitting applications. Radio-frequency plasma-enhanced deposition was used to realize multiple layers of nano-crystalline silicon while reactive ion etching was employed to create nano-scale features. The physical characteristics of the films prepared using different plasma conditions were investigated using scanning electron microscopy, transmission electron microscopy, room temperature photoluminescence and infrared spectroscopy. The formation of multilayered structures improved the photon-emission properties as observed by photoluminescence and a thin layer of silicon oxy-nitride was then used for electrical isolation between adjacent silicon layers. The preparation of light-emitting diodes directly on glass substrates has been demonstrated and the electroluminescence spectrum has been measured.

  1. Design and development of fluidized bed reactor system for production of trichlorosilane as a precursor for high purity silicon

    International Nuclear Information System (INIS)

    Kumar, Rajesh; Mohan, Sadhana; Bhanja, K.; Nayak, S.; Bhattacharya, S.K.

    2009-01-01

    Trichlorosilane is widely used as precursor material for production of high purity silicon. It is mainly produced by reaction of metallurgical grade silicon with anhydrous HCl gas in a fluidized bed reactor. To develop this process on commercial scale a pilot size fluidized bed reactor system was designed and developed and successfully operated. This paper discusses the critical issues related to these activities. (author)

  2. Very high-cycle fatigue failure in micron-scale polycrystalline silicon films : Effects of environment and surface oxide thickness

    NARCIS (Netherlands)

    Alsem, D. H.; Boyce, B. L.; Stach, E. A.; De Hosson, J. Th. M.; Ritchie, R. O.

    2007-01-01

    Fatigue failure in micron-scale polycrystalline silicon structural films, a phenomenon that is not observed in bulk silicon, can severely impact the durability and reliability of microelectromechanical system devices. Despite several studies on the very high-cycle fatigue behavior of these films (up

  3. Burnout in Oncology: a study of Nursing professionals

    Directory of Open Access Journals (Sweden)

    Stephanie Kitze

    2008-09-01

    Full Text Available Objective: To verify if licensed practical nurses and Nursing technicians working at an Oncology department present burnout syndrome. Methods: Data of 21 licensed practical nurses and Nursing technicians who had worked for, at least, one year at the Oncology department of a large hospital in the city of São Paulo, Brazil, were collected. The burnout inventory developed by Maslach and Jackson was used. Rresults: The studied population presented burnout based on scores in each of its three dimensions: emotional exhaustion, depersonalization and lack of personal accomplishment. As to burnout symptoms, this study showed that 28.6% of the sample presented high scores in “emotional exhaustion”; 28.6% had high scores in “depersonalization” and 19.1% in lack of “personal accomplishment”. Cconclusions: When compared to other studies with nurses, this sample presented greater burnout.

  4. [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.

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

    KAUST Repository

    Cui, Li-Feng; Ruffo, Riccardo; Chan, Candace K.; Peng, Hailin; Cui, Yi

    2009-01-01

    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

  6. Research, development and pilot production of high output thin silicon solar cells

    Science.gov (United States)

    Iles, P. A.

    1976-01-01

    Work was performed to define and apply processes which could lead to high output from thin (2-8 mils) silicon solar cells. The overall problems are outlined, and two satisfactory process sequences were developed. These sequences led to good output cells in the thickness range to just below 4 mils; although the initial contract scope was reduced, one of these sequences proved capable of operating beyond a pilot line level, to yield good quality 4-6 mil cells of high output.

  7. [Psychiatrist burnout or psychiatric assistance burnout?

    Science.gov (United States)

    Manna, Vincenzo; Dicuonzo, Francesca

    2018-01-01

    In recent years, mature industrial countries are rapidly changing from production economies to service economies. In this new socio-economic context, particular attention has been paid to mental health problems in the workplace. The risk of burnout is significantly higher for certain occupations, in particular for health workers. Doctors and psychiatrists, in particular, quite frequently have to make quick decisions by dealing with a huge amount of requests, which often require considerable assumptions of responsibility. In Italy, the process of corporateization and regionalization of the National Health Service has oriented clinical practice, in psychiatry, towards the rationalization and optimization of available resources, to ensure appropriateness and fairness of performances. The challenge that will soon be faced in health policy, with the progressive aging of the population, will be the growing burden of chronicity, in a context of limited resources, which will necessarily require a managerial approach in structuring and delivering services. The management of change in psychiatric assistance, today in Italy, can not be separated from a deep motivating involvement ( engagement) of professionals. In other words, it is desirable, in the effort to contain expenditure and rationalize welfare processes, to shift from burnout to the engagement of psychiatrists, investing economic and human resources in mental health services. In this review, through a selective search of the relevant literature 2010-2017 conducted on PubMed (key words: stress, burnout, psychiatry, mental health), the information from original articles, reviews and book chapters was analyzed and summarized. about the presence of burnout syndrome among psychiatrists. This article examines the concept of burnout, its causes and the most appropriate preventive and therapeutic interventions applicable to psychiatrists.

  8. 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.

  9. '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

  10. Enabling electrolyte compositions for columnar silicon anodes in high energy secondary batteries

    Science.gov (United States)

    Piwko, Markus; Thieme, Sören; Weller, Christine; Althues, Holger; Kaskel, Stefan

    2017-09-01

    Columnar silicon structures are proven as high performance anodes for high energy batteries paired with low (sulfur) or high (nickel-cobalt-aluminum oxide, NCA) voltage cathodes. The introduction of a fluorinated ether/sulfolane solvent mixture drastically improves the capacity retention for both battery types due to an improved solid electrolyte interface (SEI) on the surface of the silicon electrode which reduces irreversible reactions normally causing lithium loss and rapid capacity fading. For the lithium silicide/sulfur battery cycling stability is significantly improved as compared to a frequently used reference electrolyte (DME/DOL) reaching a constant coulombic efficiency (CE) as high as 98%. For the silicon/NCA battery with higher voltage, the addition of only small amounts of fluoroethylene carbonate (FEC) to the novel electrolyte leads to a stable capacity over at least 50 cycles and a CE as high as 99.9%. A high volumetric energy density close to 1000 Wh l-1 was achieved with the new electrolyte taking all inactive components of the stack into account for the estimation.

  11. The ocular response to extended wear of a high Dk silicone hydrogel contact lens.

    Science.gov (United States)

    Fonn, Desmond; MacDonald, Karen E; Richter, Doris; Pritchard, Nicola

    2002-05-01

    A four-month extended wear clinical trial was conducted to compare the ocular effects of a high Dk Balafilcon A silicone hydrogel lens and a low Dk HEMA 38.6 per cent H20 soft lens. Twenty-four subjects who were adapted to daily wear of soft lenses wore a high Dk lens in one eye and a low Dk HEMA lens in the other eye for four months on an extended wear basis after one week of daily wear. Thirteen progress evaluations were conducted using standard clinical procedures. Eighteen subjects (75 per cent) completed the study. The high Dk lens induced significantly less bulbar and limbal injection and corneal vascularisation than the low Dk HEMA lens (p Dk lens. A significant increase in myopia was found in the eyes wearing the low Dk HEMA lens (mean = 0.50 D, p Dk lens. Three subjects developed small infiltrates in the high Dk lens wearing eyes and significantly more post-lens debris was observed under the high Dk lens. Six subjects developed papillary conjunctivitis in the eye wearing silicone hydrogel lenses but only two of those were discontinued from the study. No hypoxia-related effects were observed with extended wear of the high Dk Balafilcon A silicone hydrogel lens.

  12. [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 (P<.0001), working in rural areas (P=.008), and to be an area doctor (p=.03), predisposes to suffer burnout 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.

  13. [Stress and burnout among Tunisian teachers].

    Science.gov (United States)

    Chennoufi, L; Ellouze, F; Cherif, W; Mersni, M; M'rad, M F

    2012-12-01

    Burnout, or professional exhaustion syndrome, is defined as a state of emotional, mental and physical exhaustion caused by excessive and prolonged stress at work. Despite the fact that it is not a recognized disorder in the DSM-IV, burnout has been widely described among medical and paramedical staff. In Tunisia, all the studies about this syndrome have only considered populations of doctors. However, professional exhaustion syndrome is not only limited to the medical sector, but can also be seen in any profession involving a relation of help. Thus, the teaching profession seems to be concerned with this syndrome. In fact, in our clinical practice, we are increasingly confronted with teachers' suffering. The latter face increasing difficulties in their work and moreover some of them can no longer resist and thus become vulnerable to the professional exhaustion syndrome. The aim of this study was to evaluate burnout among a population of Tunisian teachers and to examine the professional stressors associated with teachers' burnout. Our study was a transversal study conducted over five months (from October 2009 to February 2010) and it concerned teachers working in the public high schools of Manouba (Tunisia). The participants completed a self-questionnaire dealing with professional stressors. Five types of professional stressors were identified in the literature: bad working conditions, work overload, administrative difficulties, organizational factors and difficulties with pupils and their relatives. They were also explored by the scale of the burnout: the Maslach Burnout Inventory (MBI), which is the best-studied measurement of burnout in the literature. We used the French version of the MBI adapted to educational settings. It is a scale composed of 22 items and three dimensions: emotional exhaustion (nine items), dehumanization (five items) and reduced personal accomplishment (eight items). In our study, we considered a teacher was suffering from burnout when at

  14. Characterisation and stabilisation of the surface region of a highly polished silicon crystal sphere

    International Nuclear Information System (INIS)

    Kenny, M.J.; Wielunski, L.S.

    1999-01-01

    Full text: Typically a single crystal silicon wafer has a native oxide layer a few nm thick which changes slowly with time. A number of parameters such as hydrocarbons, water vapour, storage environment can affect this layer. The thickness of the layer is also orientation dependent. In the case of a silicon sphere the situation becomes more complex, because all orientations are present and the process of polishing involves a higher pressure and also high local temperatures. A highly polished single crystal sphere 93.6 mm in diameter is being used to determine the Avogadro constant with an uncertainty of ≤ 1 x 10 -8 . This will then be used to obtain an atomic definition of the kilogram. The composition and structure of the surface oxide layer play an important role in this measurement. Firstly the density of the oxide layer is different from that of silicon. Secondly since the diameter is measured by optical interferometry, corrections must be applied for the phase change in the reflected light beam due to the surface layer. Thirdly the orientation dependence of the layer complicated the corrections to be applied. Fourthly if measurements are made over a period of time, any changes in the surface layer must be taken into account. Given the accuracy required in the determination, the surface layer is a determining factor in the final result. A number of techniques such as spectroscopic ellipsometry and ion beam analysis are being used to study the composition and structure of the surface of a silicon sphere. Cleaning techniques such as HF and low temperature ultraviolet (ozone) are being developed to produce a clean surface. The next step involves deposition of a stable and uniform surface oxide layer a few nm thick. Techniques being investigated for this include ultra violet ozone deposition at 450 deg C and plasma deposition. The paper describes work at the NML in achieving an appropriate stable surface on the silicon sphere

  15. Burnout en estudiantes universitarios

    OpenAIRE

    Caballero, Carmen Cecilia; Bresó Esteve, Edgar; González Gutiérrez, Orlando

    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 to the university academic context is performed. It is proposed its delimitation, differentiation and relationship with comorbid clinical conditions like depression and anxiety. Additionally, this paper reviews empirical research that establishes relationships of the academic burnout with th...

  16. Burn-out

    OpenAIRE

    Patricia van Echtelt

    2014-01-01

    Deze publicatie is alleen elektronisch verkrijgbaar (downloaden van deze site) Burn-out (ofwel: emotionele uitputting) komt relatief vaak voor: ongeveer één op de acht werknemers in Nederland heeft er last van. Het wordt dan ook gezien als een serieus maatschappelijk probleem dat beleidsmatig aandacht vergt. Dit rapport presenteert de resultaten van twee specifieke analyses over burn-out. Ten eerste gaan we na wat het effect is van emotionele uitputting op de loopbaan van werknemers. Ten twee...

  17. Sense of meaning as a predictor of burnout in emergency physicians in Israel: a national survey.

    Science.gov (United States)

    Ben-Itzhak, Shulamit; Dvash, Jonathan; Maor, Maya; Rosenberg, Noa; Halpern, Pinchas

    2015-12-01

    Burnout is common in physicians and particularly acute in emergency physicians. Physician burnout may adversely affect physicians' lives and the quality of care they provide, but much remains unknown about its main contributing factors. The present study evaluated burnout rates and contributing factors in emergency physicians in Israel, specifically focusing on the role of a sense of meaning, which has received little attention in the literature concerning burnout in emergency physicians. A multicenter study, involving a convenience sample of physicians working full-time in the emergency departments of 16 general hospitals in Israel, was conducted. Questionnaires were used to assess burnout, demographic characteristics, professional stress, emotional distress, satisfaction, and quality of professional life, and open-ended questions were used to evaluate subjective perception of job satisfaction. Seventy physicians completed the questionnaires; 71.4% reported significant burnout levels in at least one of the burnout measures, while 82% also reported medium or high levels of competency. Burnout levels were associated with work-life balance, work satisfaction, social support, depressive symptoms, stress, and preoccupying thoughts. Regression analysis yielded two significant factors associated with burnout: worry and a sense of existential meaning derived from work. In addition, 61%, 51%, and 17% of participants exhibited high emotional exhaustion, high depersonalization, and a low sense of personal accomplishment, respectively. These results indicate a high burnout rate in emergency physicians in Israel and highlight relevant positive and negative factors including the importance of addressing existential meaning in designing specific intervention programs to counter burnout.

  18. Formation of hypereutectic silicon particles in hypoeutectic Al-Si alloys under the influence of high-intensity ultrasonic vibration

    Directory of Open Access Journals (Sweden)

    Xiaogang Jian

    2013-03-01

    Full Text Available The modification of eutectic silicon is of general interest since fine eutectic silicon along with fine primary aluminum grains improves mechanical properties and ductilities. In this study, high intensity ultrasonic vibration was used to modify the complex microstructure of aluminum hypoeutectic alloys. The ultrasonic vibrator was placed at the bottom of a copper mold with molten aluminum. Hypoeutectic Al-Si alloy specimens with a unique in-depth profile of microstructure distribution were obtained. Polyhedral silicon particles, which should form in a hypereutectic alloy, were obtained in a hypoeutectic Al-Si alloy near the ultrasonic radiator where the silicon concentration was higher than the eutectic composition. The formation of hypereutectic silicon near the radiator surface indicates that high-intensity ultrasonic vibration can be used to influence the phase transformation process of metals and alloys. The size and morphology of both the silicon phase and the aluminum phase varies with increasing distance from the ultrasonic probe/radiator. Silicon morphology develops into three zones. Polyhedral primary silicon particles present in zone I, within 15 mm from the ultrasonic probe/radiator. Transition from hypereutectic silicon to eutectic silicon occurs in zone II about 15 to 20 祄 from the ultrasonic probe/radiator. The bulk of the ingot is in zone III and is hypoeutectic Al-Si alloy containing fine lamellar and fibrous eutectic silicon. The grain size is about 15 to 25 祄 in zone I, 25 to 35 祄 in zone II, and 25 to 55 祄 in zone III. The morphology of the primary ?Al phase is also changed from dendritic (in untreated samples to globular. Phase evolution during the solidification process of the alloy subjected to ultrasonic vibration is described.

  19. Burnout Among Cardiologists.

    Science.gov (United States)

    Michel, Jeffrey B; Sangha, Denisse M; Erwin, John P

    2017-03-15

    Burnout is a loss of enthusiasm for work, cynicism, and a low sense of accomplishment. Loss of autonomy and authority, complex regulatory requirements, report cards, quality metrics, the rise of large integrated health care systems, and the demise of solo practice are just a few realities of medical practice that contribute to physician burnout. Physicians suffering burnout often focus on compensation and perceived status as antidotes, although evidence suggests they play no role. Randomized controlled trials suggest that interventions designed to improve coping and resiliency including cognitive behavioral therapy and physical and mental relaxations to reduce stress can be effective. Reduced work hours have also been shown to mitigate burnout. Successful prevention and management requires adaptations by both physicians and the health care systems in which they work. We believe that burnout also involves a loss of faith in the practice of medicine itself. Advances in cardiovascular medicine have led to large reductions in mortality and morbidity. However, the disruptive changes to health care that accompanied this success have contributed to physician alienation. In conclusion, we believe that to overcome burnout, cardiologists should dedicate themselves to a collective mission of patient care and work to restore faith in their profession. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Risk of burnout among early career mental health professionals.

    Science.gov (United States)

    Volpe, U; Luciano, M; Palumbo, C; Sampogna, G; Del Vecchio, V; Fiorillo, A

    2014-01-01

    Burnout is a stress-related syndrome that often affects mental health professionals (MHPs) and may have serious consequences on personal well-being as well as on the quality of provided psychiatric care. Established literature shows a high risk to develop burnout among MHPs. Few data are available on the incidence and on the clinical implications of the burnout syndrome in the early phases of MHP professional career. We confirmed the presence of burnout among early career MHPs: early career psychiatrists showed a lower sense of personal accomplishment, while non-medical MHPs tended to have more depersonalization and suffered from higher levels of depression. Specific programmes to identify the presence of the burnout syndrome and to cope with it should be taught within mental health training curricula. Burnout is a stress-related syndrome that often affects professionals working in emotionally loaded and highly interpersonal environments. Mental health professionals (MHPs) are long known to be at high risk to develop the burnout syndrome, but this has rarely been investigated in professionals in an early phase of career. The aim of the present study was to evaluate the presence of the burnout syndrome and of depressive symptoms among early career psychiatrists and 'non-medical' MHPs. One hundred MHPs (including 50 psychiatrists and 50 non-medical MHPs) were screened for the presence of burnout and depression, with the Maslach Burnout Inventory and the Beck Depression Inventory - revised, respectively. The relationships of burnout with socio-demographical and professional characteristics were also explored. We confirmed the presence of burnout among both groups of early career MHPs, but psychiatrists had a significantly higher degree of emotional exhaustion and a lower sense of personal accomplishment, while non-medical MHPs adopted more frequently depersonalization as a coping strategy and had higher scores for depression, which is associated with higher level of

  1. Soft Functional Silicone Elastomers with High Dielectric Permittivty: Simple Additives vs. Cross-Linked Synthesized Copolymers

    DEFF Research Database (Denmark)

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

    Though dielectric elastomers (DEs) have many favorable properties, the issue of high driving voltages limits the commercial viability of the technology. Improved actuation at lower voltages can be obtained by decreasing the Young’s modulus and/or decreasing the dielectric permittivity of the elas......Though dielectric elastomers (DEs) have many favorable properties, the issue of high driving voltages limits the commercial viability of the technology. Improved actuation at lower voltages can be obtained by decreasing the Young’s modulus and/or decreasing the dielectric permittivity...... of the elastomer. A decrease in Young’s modulus, however, is often accompanied by the loss of mechanical stability and thereby the lifetime of the DE whereas addition of high permittivity fillers such as metal oxides often increases Young’s modulus such that improved actuation is not accomplished. New soft...... silicone elastomers with high dielectric permittivity were prepared through the use of chloropropyl-functional silicones. One method was through the synthesis of modular cross-linkable chloropropyl-functional copolymers that allow for a high degree of chemical freedom such that a tuneable silicone...

  2. Highly Porous Silicon Embedded in a Ceramic Matrix: A Stable High-Capacity Electrode for Li-Ion Batteries.

    Science.gov (United States)

    Vrankovic, Dragoljub; Graczyk-Zajac, Magdalena; Kalcher, Constanze; Rohrer, Jochen; Becker, Malin; Stabler, Christina; Trykowski, Grzegorz; Albe, Karsten; Riedel, Ralf

    2017-11-28

    We demonstrate a cost-effective synthesis route that provides Si-based anode materials with capacities between 2000 and 3000 mAh·g Si -1 (400 and 600 mAh·g composite -1 ), Coulombic efficiencies above 99.5%, and almost 100% capacity retention over more than 100 cycles. The Si-based composite is prepared from highly porous silicon (obtained by reduction of silica) by encapsulation in an organic carbon and polymer-derived silicon oxycarbide (C/SiOC) matrix. Molecular dynamics simulations show that the highly porous silicon morphology delivers free volume for the accommodation of strain leading to no macroscopic changes during initial Li-Si alloying. In addition, a carbon layer provides an electrical contact, whereas the SiOC matrix significantly diminishes the interface between the electrolyte and the electrode material and thus suppresses the formation of a solid-electrolyte interphase on Si. Electrochemical tests of the micrometer-sized, glass-fiber-derived silicon demonstrate the up-scaling potential of the presented approach.

  3. J. Edward Berk distinguished lecture: avoiding burnout: finding balance between work and everything else.

    Science.gov (United States)

    Surawicz, Christina M

    2014-04-01

    Burnout has been defined as "a state of mental exhaustion caused by one's professional life." Increasing evidence shows high rates of burnout among medical professionals, including gastroenterologists. Factors that contribute to burnout include work-home conflict and longer work hours. Among gastroenterologists, the risk for burnout seems to be highest during the first three years on the job after fellowship. Strategies to treat and prevent burnout include identifying and balancing personal and professional goals, shaping one's career to optimize meaning, identifying stressors, and nurturing wellness strategies.

  4. High energy heavy ion beam lithography in silicon

    International Nuclear Information System (INIS)

    Rout, Bibhudutta; Dymnikov, Alexander D.; Zachry, Daniel P.; Eschenazi, Elia V.; Wang, Yongqiang Q.; Greco, Richard R.; Glass, Gary A.

    2007-01-01

    As high energy ions travel through a crystalline semiconductor materials they produce damage along the path which results in resistance to some of the wet chemical etching. A series of preliminary experiments have been performed at the Louisiana Accelerator Center (LAC) to examine the feasibility of irradiating high energy (keV-MeV) ions such as protons, xenon and gold through microscale masked structures on crystalline (n-type) Si substrates followed by wet chemical etch with KOH for attaining deep micromachining in Si. The results of these experiments are reported

  5. Work stress, poor recovery and burnout in teachers.

    Science.gov (United States)

    Gluschkoff, K; Elovainio, M; Kinnunen, U; Mullola, S; Hintsanen, M; Keltikangas-Järvinen, L; Hintsa, T

    2016-10-01

    Both work stress and poor recovery have been shown to contribute to the development of burnout. However, the role of recovery as a mediating mechanism that links work stress to burnout has not been sufficiently addressed in research. To examine recovery as a mediator in the relationship between work stress and burnout among teachers. A cross-sectional study of Finnish primary school teachers, in whom burnout was measured with the Maslach Burnout Inventory-General Survey and work stress was conceptualized using the effort-reward imbalance (ERI) model. Recovery was measured with the Recovery Experience Questionnaire and the Jenkins Sleep Problems Scale. Multiple linear regression analyses and bootstrap mediation analyses adjusted for age, gender and total working hours were performed. Among the 76 study subjects, high ERI was associated with burnout and its dimensions of exhaustion, cynicism and reduced professional efficacy. Poor recovery experiences, in terms of low relaxation during leisure time, partially mediated the relationship between ERI and reduced professional efficacy. Sleep problems, in the form of non-restorative sleep, partially mediated the relationship between ERI and both burnout and exhaustion. Supporting a balance between effort and reward at work may enhance leisure time recovery and improve sleep quality, as well as help to reduce burnout rates. © The Author 2016. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. 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.

  7. Prevalence and correlates of burnout in health professionals in Ecuador.

    Science.gov (United States)

    Ramírez, Marina R; Otero, Patricia; Blanco, Vanessa; Ontaneda, Mercy P; Díaz, Olga; Vázquez, Fernando L

    2018-04-01

    Although burnout is a widespread phenomenon among healthcare professionals, there are no studies about its prevalence in Ecuador. This study assesses the prevalence of burnout syndrome among Ecuadorian healthcare professionals and examine the relationship with their personal and organizational characteristics. A total of 2404 healthcare professionals (average age 40.0years; 68.4% women) from the capitals of all 24 provinces in Ecuador participated in this study. Trained psychologists assessed the presence of burnout by applying the Maslach Burnout Inventory. Sociodemographic variables, emotional distress, social support and coping styles as well as organizational variables were also collected. Of all healthcare professionals surveyed, 2.6% presented burnout syndrome. By dimensions, 17.2% of the participants presented a high level of emotional exhaustion, 13.5% of depersonalization, and 18.2% had reduced personal accomplishment. Being non-mestizo, being classified as a probable case of mental disorder and using more passive coping were associated with a greater probability of presenting burnout; having >10years of experience was associated with a lower probability of burnout. A significant number of active health professionals suffer from burnout. It is necessary to develop effective psychotherapeutic interventions for those who have the syndrome and to evaluate potential prevention strategies in those who have not yet developed it. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Low cost silicon solar array project: Feasibility of low-cost, high-volume production of silane and pyrolysis of silane to semiconductor-grade silicon

    Science.gov (United States)

    Breneman, W. C.

    1978-01-01

    Silicon epitaxy analysis of silane produced in the Process Development Unit operating in a completely integrated mode consuming only hydrogen and metallurgical silicon resulted in film resistivities of up to 120 ohms cm N type. Preliminary kinetic studies of dichlorosilane disproportionation in the liquid phase have shown that 11.59% SiH4 is formed at equilibrium after 12 minutes contact time at 56 C. The fluid-bed reactor was operated continuously for 48 hours with a mixture of one percent silane in helium as the fluidizing gas. A high silane pyrolysis efficiency was obtained without the generation of excessive fines. Gas flow conditions near the base of the reactor were unfavorable for maintaining a bubbling bed with good heat transfer characteristics. Consequently, a porous agglomerate formed in the lower portion of the reactor. Dense coherent plating was obtained on the silicon seed particles which had remained fluidizied throughout the experiment.

  9. Highly stressed carbon film coatings on silicon potential applications

    CERN Multimedia

    Sharda, T

    2002-01-01

    The fabrication of highly stressed and strongly adhered nanocrystalline diamond films on Si substrates is presented. A microwave plasma CVD method with controlled and continuous bias current density was used to grow the films. The stress/curvature of the films can be varied and controlled by altering the BCD. Potential applications for these films include particle physics and x-ray optics.

  10. 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.

  11. Method for producing evaporation inhibiting coating for protection of silicon--germanium and silicon--molybdenum alloys at high temperatures in vacuum

    Science.gov (United States)

    Chao, P.J.

    1974-01-01

    A method is given for protecting Si--Ge and Si-- Mo alloys for use in thermocouples. The alloys are coated with silicon to inhibit the evaporation of the alloys at high tempenatures in a vacuum. Specific means and methods are provided. (5 fig) (Official Gazette)

  12. [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.

  13. Amorphous Silicon-Germanium Films with Embedded Nanocrystals for Thermal Detectors with Very High Sensitivity

    Directory of Open Access Journals (Sweden)

    Cesar Calleja

    2016-01-01

    Full Text Available We have optimized the deposition conditions of amorphous silicon-germanium films with embedded nanocrystals in a plasma enhanced chemical vapor deposition (PECVD reactor, working at a standard frequency of 13.56 MHz. The objective was to produce films with very large Temperature Coefficient of Resistance (TCR, which is a signature of the sensitivity in thermal detectors (microbolometers. Morphological, electrical, and optical characterization were performed in the films, and we found optimal conditions for obtaining films with very high values of thermal coefficient of resistance (TCR = 7.9% K−1. Our results show that amorphous silicon-germanium films with embedded nanocrystals can be used as thermosensitive films in high performance infrared focal plane arrays (IRFPAs used in commercial thermal cameras.

  14. Highly Sensitive Bulk Silicon Chemical Sensors with Sub-5 nm Thin Charge Inversion Layers.

    Science.gov (United States)

    Fahad, Hossain M; Gupta, Niharika; Han, Rui; Desai, Sujay B; Javey, Ali

    2018-03-27

    There is an increasing demand for mass-producible, low-power gas sensors in a wide variety of industrial and consumer applications. Here, we report chemical-sensitive field-effect-transistors (CS-FETs) based on bulk silicon wafers, wherein an electrostatically confined sub-5 nm thin charge inversion layer is modulated by chemical exposure to achieve a high-sensitivity gas-sensing platform. Using hydrogen sensing as a "litmus" test, we demonstrate large sensor responses (>1000%) to 0.5% H 2 gas, with fast response (<60 s) and recovery times (<120 s) at room temperature and low power (<50 μW). On the basis of these performance metrics as well as standardized benchmarking, we show that bulk silicon CS-FETs offer similar or better sensing performance compared to emerging nanostructures semiconductors while providing a highly scalable and manufacturable platform.

  15. Cryogenic Etching of High Aspect Ratio 400 nm Pitch Silicon Gratings.

    Science.gov (United States)

    Miao, Houxun; Chen, Lei; Mirzaeimoghri, Mona; Kasica, Richard; Wen, Han

    2016-10-01

    The cryogenic process and Bosch process are two widely used processes for reactive ion etching of high aspect ratio silicon structures. This paper focuses on the cryogenic deep etching of 400 nm pitch silicon gratings with various etching mask materials including polymer, Cr, SiO 2 and Cr-on-polymer. The undercut is found to be the key factor limiting the achievable aspect ratio for the direct hard masks of Cr and SiO 2 , while the etch selectivity responds to the limitation of the polymer mask. The Cr-on-polymer mask provides the same high selectivity as Cr and reduces the excessive undercut introduced by direct hard masks. By optimizing the etching parameters, we etched a 400 nm pitch grating to ≈ 10.6 μ m depth, corresponding to an aspect ratio of ≈ 53.

  16. Amorphous Silicon-Germanium Films with Embedded Nano crystals for Thermal Detectors with Very High Sensitivity

    International Nuclear Information System (INIS)

    Calleja, C.; Torres, A.; Rosales-Quintero, P.; Moreno, M.

    2016-01-01

    We have optimized the deposition conditions of amorphous silicon-germanium films with embedded nano crystals in a plasma enhanced chemical vapor deposition (PECVD) reactor, working at a standard frequency of 13.56 MHz. The objective was to produce films with very large Temperature Coefficient of Resistance (TCR), which is a signature of the sensitivity in thermal detectors (micro bolometers). Morphological, electrical, and optical characterization were performed in the films, and we found optimal conditions for obtaining films with very high values of thermal coefficient of resistance (TCR = 7.9%K -1 ). Our results show that amorphous silicon-germanium films with embedded nano crystals can be used as thermo sensitive films in high performance infrared focal plane arrays (IRFPAs) used in commercial thermal cameras.

  17. 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…

  18. Simultaneous high crystallinity and sub-bandgap optical absorptance in hyperdoped black silicon using nanosecond laser annealing

    Energy Technology Data Exchange (ETDEWEB)

    Franta, Benjamin, E-mail: bafranta@gmail.com; Pastor, David; Gandhi, Hemi H.; Aziz, Michael J.; Mazur, Eric [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Rekemeyer, Paul H.; Gradečak, Silvija [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-12-14

    Hyperdoped black silicon fabricated with femtosecond laser irradiation has attracted interest for applications in infrared photodetectors and intermediate band photovoltaics due to its sub-bandgap optical absorptance and light-trapping surface. However, hyperdoped black silicon typically has an amorphous and polyphasic polycrystalline surface that can interfere with carrier transport, electrical rectification, and intermediate band formation. Past studies have used thermal annealing to obtain high crystallinity in hyperdoped black silicon, but thermal annealing causes a deactivation of the sub-bandgap optical absorptance. In this study, nanosecond laser annealing is used to obtain high crystallinity and remove pressure-induced phases in hyperdoped black silicon while maintaining high sub-bandgap optical absorptance and a light-trapping surface morphology. Furthermore, it is shown that nanosecond laser annealing reactivates the sub-bandgap optical absorptance of hyperdoped black silicon after deactivation by thermal annealing. Thermal annealing and nanosecond laser annealing can be combined in sequence to fabricate hyperdoped black silicon that simultaneously shows high crystallinity, high above-bandgap and sub-bandgap absorptance, and a rectifying electrical homojunction. Such nanosecond laser annealing could potentially be applied to non-equilibrium material systems beyond hyperdoped black silicon.

  19. Highly sensitive and selective detection of dopamine using one-pot synthesized highly photoluminescent silicon nanoparticles.

    Science.gov (United States)

    Zhang, Xiaodong; Chen, Xiaokai; Kai, Siqi; Wang, Hong-Yin; Yang, Jingjing; Wu, Fu-Gen; Chen, Zhan

    2015-03-17

    A simple and highly efficient method for dopamine (DA) detection using water-soluble silicon nanoparticles (SiNPs) was reported. The SiNPs with a high quantum yield of 23.6% were synthesized by using a one-pot microwave-assisted method. The fluorescence quenching capability of a variety of molecules on the synthesized SiNPs has been tested; only DA molecules were found to be able to quench the fluorescence of these SiNPs effectively. Therefore, such a quenching effect can be used to selectively detect DA. All other molecules tested have little interference with the dopamine detection, including ascorbic acid, which commonly exists in cells and can possibly affect the dopamine detection. The ratio of the fluorescence intensity difference between the quenched and unquenched cases versus the fluorescence intensity without quenching (ΔI/I) was observed to be linearly proportional to the DA analyte concentration in the range from 0.005 to 10.0 μM, with a detection limit of 0.3 nM (S/N = 3). To the best of our knowledge, this is the lowest limit for DA detection reported so far. The mechanism of fluorescence quenching is attributed to the energy transfer from the SiNPs to the oxidized dopamine molecules through Förster resonance energy transfer. The reported method of SiNP synthesis is very simple and cheap, making the above sensitive and selective DA detection approach using SiNPs practical for many applications.

  20. High-performance silicon photonics technology for telecommunications applications.

    Science.gov (United States)

    Yamada, Koji; Tsuchizawa, Tai; Nishi, Hidetaka; Kou, Rai; Hiraki, Tatsurou; Takeda, Kotaro; Fukuda, Hiroshi; Ishikawa, Yasuhiko; Wada, Kazumi; Yamamoto, Tsuyoshi

    2014-04-01

    By way of a brief review of Si photonics technology, we show that significant improvements in device performance are necessary for practical telecommunications applications. In order to improve device performance in Si photonics, we have developed a Si-Ge-silica monolithic integration platform, on which compact Si-Ge-based modulators/detectors and silica-based high-performance wavelength filters are monolithically integrated. The platform features low-temperature silica film deposition, which cannot damage Si-Ge-based active devices. Using this platform, we have developed various integrated photonic devices for broadband telecommunications applications.

  1. High-performance silicon photonics technology for telecommunications applications

    International Nuclear Information System (INIS)

    Yamada, Koji; Tsuchizawa, Tai; Nishi, Hidetaka; Kou, Rai; Hiraki, Tatsurou; Takeda, Kotaro; Fukuda, Hiroshi; Yamamoto, Tsuyoshi; Ishikawa, Yasuhiko; Wada, Kazumi

    2014-01-01

    By way of a brief review of Si photonics technology, we show that significant improvements in device performance are necessary for practical telecommunications applications. In order to improve device performance in Si photonics, we have developed a Si-Ge-silica monolithic integration platform, on which compact Si-Ge–based modulators/detectors and silica-based high-performance wavelength filters are monolithically integrated. The platform features low-temperature silica film deposition, which cannot damage Si-Ge–based active devices. Using this platform, we have developed various integrated photonic devices for broadband telecommunications applications. (review)

  2. High-performance silicon photonics technology for telecommunications applications

    Science.gov (United States)

    Yamada, Koji; Tsuchizawa, Tai; Nishi, Hidetaka; Kou, Rai; Hiraki, Tatsurou; Takeda, Kotaro; Fukuda, Hiroshi; Ishikawa, Yasuhiko; Wada, Kazumi; Yamamoto, Tsuyoshi

    2014-04-01

    By way of a brief review of Si photonics technology, we show that significant improvements in device performance are necessary for practical telecommunications applications. In order to improve device performance in Si photonics, we have developed a Si-Ge-silica monolithic integration platform, on which compact Si-Ge-based modulators/detectors and silica-based high-performance wavelength filters are monolithically integrated. The platform features low-temperature silica film deposition, which cannot damage Si-Ge-based active devices. Using this platform, we have developed various integrated photonic devices for broadband telecommunications applications.

  3. High-contrast gratings for long-wavelength laser integration on silicon

    Science.gov (United States)

    Sciancalepore, Corrado; Descos, Antoine; Bordel, Damien; Duprez, Hélène; Letartre, Xavier; Menezo, Sylvie; Ben Bakir, Badhise

    2014-02-01

    Silicon photonics is increasingly considered as the most promising way-out to the relentless growth of data traffic in today's telecommunications infrastructures, driving an increase in transmission rates and computing capabilities. This is in fact challenging the intrinsic limit of copper-based, short-reach interconnects and microelectronic circuits in data centers and server architectures to offer enough modulation bandwidth at reasonable power dissipation. In the context of the heterogeneous integration of III-V direct-bandgap materials on silicon, optics with high-contrast metastructures enables the efficient implementation of optical functions such as laser feedback, input/output (I/O) to active/passive components, and optical filtering, while heterogeneous integration of III-V layers provides sufficient optical gain, resulting in silicon-integrated laser sources. The latest ensure reduced packaging costs and reduced footprint for the optical transceivers, a key point for the short reach communications. The invited talk will introduce the audience to the latest breakthroughs concerning the use of high-contrast gratings (HCGs) for the integration of III-V-on-Si verticalcavity surface-emitting lasers (VCSELs) as well as Fabry-Perot edge-emitters (EELs) in the main telecom band around 1.55 μm. The strong near-field mode overlap within HCG mirrors can be exploited to implement unique optical functions such as dense wavelength division multiplexing (DWDM): a 16-λ100-GHz-spaced channels VCSEL array is demonstrated. On the other hand, high fabrication yields obtained via molecular wafer bonding of III-V alloys on silicon-on-insulator (SOI) conjugate excellent device performances with cost-effective high-throughput production, supporting industrial needs for a rapid research-to-market transfer.

  4. Silicon oxide based high capacity anode materials for lithium ion batteries

    Science.gov (United States)

    Deng, Haixia; Han, Yongbong; Masarapu, Charan; Anguchamy, Yogesh Kumar; Lopez, Herman A.; Kumar, Sujeet

    2017-03-21

    Silicon oxide based materials, including composites with various electrical conductive compositions, are formulated into desirable anodes. The anodes can be effectively combined into lithium ion batteries with high capacity cathode materials. In some formulations, supplemental lithium can be used to stabilize cycling as well as to reduce effects of first cycle irreversible capacity loss. Batteries are described with surprisingly good cycling properties with good specific capacities with respect to both cathode active weights and anode active weights.

  5. An improved PIN photodetector with integrated JFET on high-resistivity silicon

    International Nuclear Information System (INIS)

    Dalla Betta, Gian-Franco; Piemonte, Claudio; Boscardin, Maurizio; Gregori, Paolo; Zorzi, Nicola; Fazzi, Alberto; Pignatel, Giorgio U.

    2006-01-01

    We report on a PIN photodetector integrated with a Junction Field Effect Transistor (JFET) on a high-resistivity silicon substrate. Owing to a modified fabrication technology, the electrical and noise characteristics of the JFET transistor have been enhanced with respect to the previous versions of the device, allowing the performance to be significantly improved. In this paper, the main design and technological aspects relevant to the proposed structure are addressed and experimental results from the electrical characterization are discussed

  6. High-efficiency amorphous silicon solar cell on a periodic nanocone back reflector

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Ching-Mei; Cui, Yi [Department of Materials Science and Engineering, Durand Building, 496 Lomita Mall, Stanford University, Stanford, CA 94305-4034 (United States); Battaglia, Corsin; Pahud, Celine; Haug, Franz-Josef; Ballif, Christophe [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics Laboratory, Rue Breguet 2, 2000 Neuchatel (Switzerland); Ruan, Zhichao; Fan, Shanhui [Department of Electrical Engineering, Stanford University (United States)

    2012-06-15

    An amorphous silicon solar cell on a periodic nanocone back reflector with a high 9.7% initial conversion efficiency is presented. The optimized back-reflector morphology provides powerful light trapping and enables excellent electrical cell performance. Up-scaling to industrial production of large-area modules should be possible using nanoimprint lithography. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Large-size high-performance transparent amorphous silicon sensors for laser beam position detection

    International Nuclear Information System (INIS)

    Calderon, A.; Martinez-Rivero, C.; Matorras, F.; Rodrigo, T.; Sobron, M.; Vila, I.; Virto, A.L.; Alberdi, J.; Arce, P.; Barcala, J.M.; Calvo, E.; Ferrando, A.; Josa, M.I.; Luque, J.M.; Molinero, A.; Navarrete, J.; Oller, J.C.; Yuste, C.; Koehler, C.; Lutz, B.; Schubert, M.B.; Werner, J.H.

    2006-01-01

    We present the measured performance of a new generation of semitransparent amorphous silicon position detectors. They have a large sensitive area (30x30mm 2 ) and show good properties such as a high response (about 20mA/W), an intrinsic position resolution better than 3μm, a spatial-point reconstruction precision better than 10μm, deflection angles smaller than 10μrad and a transmission power in the visible and NIR higher than 70%

  8. Dispersion engineering of thick high-Q silicon nitride ring-resonators via atomic layer deposition.

    Science.gov (United States)

    Riemensberger, Johann; Hartinger, Klaus; Herr, Tobias; Brasch, Victor; Holzwarth, Ronald; Kippenberg, Tobias J

    2012-12-03

    We demonstrate dispersion engineering of integrated silicon nitride based ring resonators through conformal coating with hafnium dioxide deposited on top of the structures via atomic layer deposition. Both, magnitude and bandwidth of anomalous dispersion can be significantly increased. The results are confirmed by high resolution frequency-comb-assisted-diode-laser spectroscopy and are in very good agreement with the simulated modification of the mode spectrum.

  9. MICROSTRUCTURING OF SILICON SINGLE CRYSTALS BY FIBER LASER IN HIGH-SPEED SCANNING MODE

    Directory of Open Access Journals (Sweden)

    T. A. Trifonova

    2015-11-01

    Full Text Available Subject of Study. The surface structure of the silicon wafers (substrate with a thermally grown silicon dioxide on the surface (of SiO2/Si is studied after irradiation by pulse fiber laser of ILI-1-20 type. The main requirements for exposure modes of the system are: the preservation of the integrity of the film of silicon dioxide in the process of microstructuring and the absence of interference of surrounding irradiated areas of the substrate. Method. Studies were carried out on silicon wafers KEF-4,5 oriented in the crystallographic plane (111 with the source (natural silicon dioxide (SiO2 with thickness of about 4 nm, and SiO2 with 40 nm and 150 nm thickness, grown by thermal oxidation in moist oxygen. Also, wafers KHB-10 oriented in the plane (100 with 500 nm thickness of thermal oxide were investigated. Irradiation of SiO2/Si system was produced by laser complex based on ytterbium fiber pulse laser ILI-1-20. Nominal output power of the laser was 20 W, and the laser wavelength was λ = 1062 nm. Irradiation was carried out by a focused beam spot with a diameter of 25 microns and a pulse repetition rate of 99 kHz. The samples with 150 nm and 40 nm thickness of SiO2 were irradiated at a power density equal to 1,2·102 W/cm2, and the samples of SiO2 with 500 nm thickness were irradiated at a power density equal to 2,0·102 W/cm2. Scanning was performed using a two-axis Coordinate Scanning Device based on VM2500+ drives with control via a PC with the software package "SinMarkTM." Only one scan line was used at the maximum speed of the beam equal to 8750 mm/s. Morphology control of the irradiated samples was conducted by an optical microscope ZeissA1M with high-resolution CCD array. A scanning probe microscope Nanoedicator of the NT-MDT company was used for structural measurements. Main Results. It has been shown that at a single exposure of high-frequency pulsed laser radiation on SiO2/Si system, with maintaining the integrity of the SiO2 film

  10. Teachers` and medics' burnout syndrome

    OpenAIRE

    VOPELKOVÁ, Kateřina

    2010-01-01

    The bachelor thesis offers an overview of information related to problems of stress and burnout syndrome. I deal mainly with causes, symptoms, risk factors, prevention and getting stress and burnout syndrome under control. The aim of my bachelor thesis is to find out symptoms of burnout syndrome at teachers and health service employees. I supposed different manifestations of the burnout syndrome due to different demands put on these people in their professions. Another aim was to establish th...

  11. A novel high pressure, high temperature vessel used to conduct long-term stability measurements of silicon MEMS pressure transducers

    Science.gov (United States)

    Wisniewiski, David

    2014-03-01

    The need to quantify and to improve long-term stability of pressure transducers is a persistent requirement from the aerospace sector. Specifically, the incorporation of real-time pressure monitoring in aircraft landing gear, as exemplified in Tire Pressure Monitoring Systems (TPMS), has placed greater demand on the pressure transducer for improved performance and increased reliability which is manifested in low lifecycle cost and minimal maintenance downtime through fuel savings and increased life of the tire. Piezoresistive (PR) silicon MEMS pressure transducers are the primary choice as a transduction method for this measurement owing to their ability to be designed for the harsh environment seen in aircraft landing gear. However, these pressure transducers are only as valuable as the long-term stability they possess to ensure reliable, real-time monitoring over tens of years. The "heart" of the pressure transducer is the silicon MEMS element, and it is at this basic level where the long-term stability is established and needs to be quantified. A novel High Pressure, High Temperature (HPHT) vessel has been designed and constructed to facilitate this critical measurement of the silicon MEMS element directly through a process of mechanically "floating" the silicon MEMS element while being subjected to the extreme environments of pressure and temperature, simultaneously. Furthermore, the HPHT vessel is scalable to permit up to fifty specimens to be tested at one time to provide a statistically significant data population on which to draw reasonable conclusions on long-term stability. With the knowledge gained on the silicon MEMS element, higher level assembly to the pressure transducer envelope package can also be quantified as to the build-effects contribution to long-term stability in the same HPHT vessel due to its accommodating size. Accordingly, a HPHT vessel offering multiple levels of configurability and robustness in data measurement is presented, along

  12. High temperature study of flexible silicon-on-insulator fin field-effect transistors

    KAUST Repository

    Diab, Amer El Hajj

    2014-09-29

    We report high temperature electrical transport characteristics of a flexible version of the semiconductor industry\\'s most advanced architecture: fin field-effect transistor on silicon-on-insulator with sub-20 nm fins and high-κ/metal gate stacks. Characterization from room to high temperature (150 °C) was completed to determine temperature dependence of drain current (Ids), gate leakage current (Igs), transconductance (gm), and extracted low-field mobility (μ0). Mobility degradation with temperature is mainly caused by phonon scattering. The other device characteristics show insignificant difference at high temperature which proves the suitability of inorganic flexible electronics with advanced device architecture.

  13. High-quality GaN nanowires grown on Si and porous silicon by thermal evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Shekari, L., E-mail: lsg09_phy089@student.usm.my [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Ramizy, A.; Omar, K.; Hassan, H. Abu; Hassan, Z. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer A new kind of substrate (porous silicon) was used. Black-Right-Pointing-Pointer Also this research introduces an easy and safe method to grow high quality GaN NWs. Black-Right-Pointing-Pointer This is a new growth process to decrease the cost, complexity of growth of GaN NWs. Black-Right-Pointing-Pointer It is a controllable method to synthesize GaN NWs by thermal evaporation. - Abstract: Nanowires (NWs) of GaN thin films were prepared on as-grown Si (1 1 1) and porous silicon (PS) substrates using thermal evaporation method. The film growth produced high-quality wurtzite GaN NWs. The size, morphology, and nanostructures of the crystals were investigated through scanning electron microscopy, high-resolution X-ray diffraction and photoluminescence spectroscopy. The NWs grown on porous silicon were thinner, longer and denser compared with those on as-grown Si. The energy band gap of the NWs grown on PS was larger than that of NWs on as-grown Si. This is due to the greater quantum confinement effects of the crystalline structure of the NWs grown on PS.

  14. Active phase correction of high resolution silicon photonic arrayed waveguide gratings.

    Science.gov (United States)

    Gehl, M; Trotter, D; Starbuck, A; Pomerene, A; Lentine, A L; DeRose, C

    2017-03-20

    Arrayed waveguide gratings provide flexible spectral filtering functionality for integrated photonic applications. Achieving narrow channel spacing requires long optical path lengths which can greatly increase the footprint of devices. High index contrast waveguides, such as those fabricated in silicon-on-insulator wafers, allow tight waveguide bends which can be used to create much more compact designs. Both the long optical path lengths and the high index contrast contribute to significant optical phase error as light propagates through the device. Therefore, silicon photonic arrayed waveguide gratings require active or passive phase correction following fabrication. Here we present the design and fabrication of compact silicon photonic arrayed waveguide gratings with channel spacings of 50, 10 and 1 GHz. The largest device, with 11 channels of 1 GHz spacing, has a footprint of only 1.1 cm2. Using integrated thermo-optic phase shifters, the phase error is actively corrected. We present two methods of phase error correction and demonstrate state-of-the-art cross-talk performance for high index contrast arrayed waveguide gratings. As a demonstration of possible applications, we perform RF channelization with 1 GHz resolution. Additionally, we generate unique spectral filters by applying non-zero phase offsets calculated by the Gerchberg Saxton algorithm.

  15. 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

  16. 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…

  17. 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

  18. Organizational Communication and Burnout Symptoms

    NARCIS (Netherlands)

    ter Hoeven, C.L.; de Jong, 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

  19. Fabrication of wear-resistant silicon microprobe tips for high-speed surface roughness scanning devices

    Science.gov (United States)

    Wasisto, Hutomo Suryo; Yu, Feng; Doering, Lutz; Völlmeke, Stefan; Brand, Uwe; Bakin, Andrey; Waag, Andreas; Peiner, Erwin

    2015-05-01

    Silicon microprobe tips are fabricated and integrated with piezoresistive cantilever sensors for high-speed surface roughness scanning systems. The fabrication steps of the high-aspect-ratio silicon microprobe tips were started with photolithography and wet etching of potassium hydroxide (KOH) resulting in crystal-dependent micropyramids. Subsequently, thin conformal wear-resistant layer coating of aluminum oxide (Al2O3) was demonstrated on the backside of the piezoresistive cantilever free end using atomic layer deposition (ALD) method in a binary reaction sequence with a low thermal process and precursors of trimethyl aluminum and water. The deposited Al2O3 layer had a thickness of 14 nm. The captured atomic force microscopy (AFM) image exhibits a root mean square deviation of 0.65 nm confirming the deposited Al2O3 surface quality. Furthermore, vacuum-evaporated 30-nm/200-nm-thick Au/Cr layers were patterned by lift-off and served as an etch mask for Al2O3 wet etching and in ICP cryogenic dry etching. By using SF6/O2 plasma during inductively coupled plasma (ICP) cryogenic dry etching, micropillar tips were obtained. From the preliminary friction and wear data, the developed silicon cantilever sensor has been successfully used in 100 fast measurements of 5- mm-long standard artifact surface with a speed of 15 mm/s and forces of 60-100 μN. Moreover, the results yielded by the fabricated silicon cantilever sensor are in very good agreement with those of calibrated profilometer. These tactile sensors are targeted for use in high-aspect-ratio microform metrology.

  20. 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...

  1. Determination of silicon and aluminum in silicon carbide nanocrystals by high-resolution continuum source graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Dravecz, Gabriella; Bencs, László; Beke, Dávid; Gali, Adam

    2016-01-15

    The determination of Al contaminant and the main component Si in silicon carbide (SiC) nanocrystals with the size-distribution of 1-8nm dispersed in an aqueous solution was developed using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS-GFAAS). The vaporization/atomization processes were investigated in a transversally heated graphite atomizer by evaporating solution samples of Al and Si preserved in various media (HCl, HNO3). For Si, the best results were obtained by applying a mixture of 5µg Pd plus 5µg Mg, whereas for Al, 10µg Mg (each as nitrate solution) was dispensed with the samples, but the results obtained without modifier were found to be better. This way a maximum pyrolysis temperature of 1200°C for Si and 1300°C for Al could be used, and the optimum (compromise) atomization temperature was 2400°C for both analytes. The Si and Al contents of different sized SiC nanocrystals, dispersed in aqueous solutions, were determined against aqueous (external) calibration standards. The correlation coefficients (R values) of the calibrations were found to be 0.9963 for Si and 0.9991 for Al. The upper limit of the linear calibration range was 2mg/l Si and 0.25mg/l Al. The limit of detection was 3µg/l for Si and 0.5µg/l for Al. The characteristic mass (m0) was calculated to be 389pg Si and 6.4pg Al. The Si and Al content in the solution samples were found to be in the range of 1.0-1.7mg/l and 0.1-0.25mg/l, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. 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.

  3. Microcyst response to high Dk/t silicone hydrogel contact lenses.

    Science.gov (United States)

    Keay, L; Sweeney, D F; Jalbert, I; Skotnitsky, C; Holden, B A

    2000-11-01

    To investigate the microcyst response to extended wear (EW) with high oxygen transmissible (Dk/t) silicone hydrogel lenses. Microcysts were monitored for 12 months in subjects wearing low Dk/t hydrogel lenses on a 6-night EW schedule or high Dk/t hydrogel lenses on a 30-night EW schedule. Subjects wearing low Dk/t lenses transferred to the high Dk/t EW lenses and schedule after 12 months and were monitored for a further 6 months. The mean number of microcysts did not deviate from baseline in the high Dk/t group. Microcysts in the low Dk/t group increased over 12 months, and more microcysts were observed in low Dk/t lens wearers compared with high Dk/t lens wearers after 3 months. Microcysts increased in 50% of subjects 1 week after transfer to high Dk/t lenses and returned to baseline levels seen with high Dk/t lens wear within 3 months. EW with high Dk/t silicone hydrogel lenses did not cause an increase in microcyst numbers. It is not necessary to discontinue lens wear with patients who transfer from low to high Dk/t lenses because the increase in microcysts is transitory. This result has implications for practitioners when fitting and assessing the success of high Dk/t hydrogel lenses.

  4. [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.

  5. 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.

  6. 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

  7. ENGAGEMENT AND BURNOUT AMONG NURSING AND PSYCHOLOGY STUDENTS IN SLOVAKIA

    Directory of Open Access Journals (Sweden)

    Zuzana Škodová

    2017-05-01

    Full Text Available Aim: The aim of the study was to examine the differences in engagement and burnout syndrome in students of nursing/midwifery and psychology in Slovakia. Design: A cross-sectional design was used. Methods: 171 university students on a baccalaureate program participated in the research (90.9% females; age 20.6 ± 1.3; 80 psychology students, 91 nursing/midwifery students. The School Burnout Inventory (SBI and Utrecht Work Engagement Scale (UWES were employed as measurement methods. Results: A significant negative association between levels of burnout and engagement (R = 0.42; p < 0.01 was found. A linear regression model showed a significant effect of engagement on burnout (β = -0.34; 95% CI: -0.50; -0.19. However, the total explained variance was only 19.4%. Students of psychology scored higher in engagement compared to nursing and midwifery students (t = 6.89; p < 0.001. Conversely, midwifery and nursing students had higher levels of burnout compared to the group of psychology students (t = -4.55; p < 0,001. Conclusion: Nursing is considered to be a high risk profession in terms of development of burnout, which was demonstrated in this study by the higher burnout, and lower engagement levels in nursing and midwifery students. Higher attention to coping mechanisms for stress and burnout symptoms among students of healthcare professions is required in the school curriculum, especially in nursing programs. Keywords: burnout syndrome, engagement, students of nursing, midwifery, students of psychology, School Burnout Inventory (SBI, Utrecht Work Engagement Scale (UWES.

  8. Gendered Pathways to Burnout: Results from the SALVEO Study.

    Science.gov (United States)

    Beauregard, Nancy; Marchand, Alain; Bilodeau, Jaunathan; Durand, Pierre; Demers, Andrée; Haines, Victor Y

    2018-02-19

    Burnout is a pervasive mental health problem in the workforce, with mounting evidence suggesting ties with occupational and safety outcomes such as work injuries, critical events and musculoskeletal disorders. While environmental [work and non-work, work-to-family conflict (WFC)] and individual (personality) pathways to burnout are well documented, little is known about how gender comes to influence such associative patterns. The aim of the study consisted in examining gendered pathways to burnout. Data were derived from the SALVEO study, a cross-sectional study of 2026 workers from 63 workplaces from the province of Québec (Canada). Data were analyzed using multilevel path analysis. Direct effects of gendered pathways were evidenced for work (e.g. decision latitude) and non-work (e.g. child-related strains) environmental pathways, as well as for individual pathways (i.e. internal locus of control). Indirect effects of gendered pathways were also evidenced, with women reporting higher levels of burnout compared to men due to lower levels of decision latitude and of self-esteem, as well as higher levels of WFC. Women also reported lower burnout levels through investing more time into domestic tasks, which could represent a recovery strategy to highly demanding work. WFC further mediated the associations between working hours and burnout, as well as the between irregular work schedules and burnout. These result suggest than men distinctively reported higher levels of burnout due to the specific nature of their work contract negatively impacting on WFC, and incidentally, on their mental health. Study results supported our hypotheses positing that gender distinctively shapes environmental and individual pathways to burnout. OHS prevention efforts striving for better mental health outcomes in the workforce could relevantly be informed by a gendered approach to burnout.

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

    Science.gov (United States)

    Kandelman, Nadia; Mazars, Thierry; Levy, Antonin

    2018-01-01

    (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.

  10. [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

  11. Effect of fabrication parameters on morphological and optical properties of highly doped p-porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Zare, Maryam, E-mail: mar.zare@gmail.com [Young Researchers Club, Khomeinishahr Branch, Islamic Azad University, Khomeinishahr (Iran, Islamic Republic of); Shokrollahi, Abbas [Young Researchers Club, Khomeinishahr Branch, Islamic Azad University, Khomeinishahr (Iran, Islamic Republic of); Seraji, Faramarz E. [Optical Communication Group, Iran Telecom Research Center, Tehran (Iran, Islamic Republic of)

    2011-09-01

    Porous silicon (PS) layers were fabricated by anodization of low resistive (highly doped) p-type silicon in HF/ethanol solution, by varying current density, etching time and HF concentration. Atomic force microscopy (AFM) and field emission scanning electron microscope (FESEM) analyses were used to investigate the physical properties and reflection spectrum was used to investigate the optical behavior of PS layers in different fabrication conditions. Vertically aligned mesoporous morphology is observed in fabricated films and with HF concentration higher than 20%. The dependence of porosity, layer thickness and rms roughness of the PS layer on current density, etching time and composition of electrolyte is also observed in obtained results. Correlation between reflectivity and fabrication parameters was also explored. Thermal oxidation was performed on some mesoporous layers that resulted in changes of surface roughness, mean height and reflectivity of the layers.

  12. A radioagent method for determination of traces of phosphorus in high-purity silicon

    International Nuclear Information System (INIS)

    Chen, P.Y.; Chen, J.S.; Sun, H.J.; Yang, M.H.

    1985-01-01

    The feasibility of the determination of phosphorus at the extreme trace levels in high-purity silicon by radioreagent method is explored. After silicon dissolution with hydrofluoric and nitric acids and matrix volatilization, 12-molybdophosphoric acid is formed by the addition of the reagent, sup(99)MoOsub(4)sup(2-), in nitric acid medium and then extracted into isobutyl acetate. By plotting the phosphorus content against the radioactivity of sup(99)Mo in the organic phase, a linear relationship persisting down to 5 ng is obtained. Special effort was made to eliminate the unreacted sup(99)MoOsub(4)sup(2-) reagent and the optimal control of phosphorus blank introduced through the multistage analytical procedure in order to ensure reliable determination of phosphorus at the ppb level. (author)

  13. Significantly High Modulation Efficiency of Compact Graphene Modulator Based on Silicon Waveguide.

    Science.gov (United States)

    Shu, Haowen; Su, Zhaotang; Huang, Le; Wu, Zhennan; Wang, Xingjun; Zhang, Zhiyong; Zhou, Zhiping

    2018-01-17

    We theoretically and experimentally demonstrate a significantly large modulation efficiency of a compact graphene modulator based on a silicon waveguide using the electro refractive effect of graphene. The modulation modes of electro-absorption and electro-refractive can be switched with different applied voltages. A high extinction ratio of 25 dB is achieved in the electro-absorption modulation mode with a driving voltage range of 0 V to 1 V. For electro-refractive modulation, the driving voltage ranges from 1 V to 3 V with a 185-pm spectrum shift. The modulation efficiency of 1.29 V · mm with a 40-μm interaction length is two orders of magnitude higher than that of the first reported graphene phase modulator. The realisation of phase and intensity modulation with graphene based on a silicon waveguide heralds its potential application in optical communication and optical interconnection systems.

  14. Ultracompact high-efficiency polarising beam splitter based on silicon nanobrick arrays.

    Science.gov (United States)

    Zheng, Guoxing; Liu, Guogen; Kenney, Mitchell Guy; Li, Zile; He, Ping'an; Li, Song; Ren, Zhi; Deng, Qiling

    2016-03-21

    Since the transmission of anisotropic nano-structures is sensitive to the polarisation of an incident beam, a novel polarising beam splitter (PBS) based on silicon nanobrick arrays is proposed. With careful design of such structures, an incident beam with polarisation direction aligned with the long axis of the nanobrick is almost totally reflected (~98.5%), whilst that along the short axis is nearly totally transmitted (~94.3%). More importantly, by simply changing the width of the nanobrick we can shift the peak response wavelength from 1460 nm to 1625 nm, covering S, C and L bands of the fiber telecommunications windows. The silicon nanobrick-based PBS can find applications in many fields which require ultracompactness, high efficiency, and compatibility with semiconductor industry technologies.

  15. High-stability transparent amorphous oxide TFT with a silicon-doped back-channel layer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyoung-Rae; Park, Jea-Gun [Hanyang University, Seoul (Korea, Republic of)

    2014-10-15

    We significantly reduced various electrical instabilities of amorphous indium gallium zinc oxide thin-film transistors (TFTs) by using the co-deposition of silicon on an a-IGZO back channel. This process showed improved stability of the threshold voltage (V{sub th}) under high temperature and humidity and negative gate-bias illumination stress (NBIS) without any reduction of IDS. The enhanced stability was achieved with silicon, which has higher metal-oxide bonding strengths than gallium does. Additionally, SiO{sub x} distributed on the a-IGZO surface reduced the adsorption and the desorption of H{sub 2}O and O{sub 2}. This process is applicable to the TFT manufacturing process with a variable sputtering target.

  16. Properties of CMOS devices and circuits fabricated on high-resistivity, detector-grade silicon

    International Nuclear Information System (INIS)

    Holland, S.

    1991-11-01

    A CMOS process that is compatible with silicon p-i-n radiation detectors has been developed and characterized. A total of twelve mask layers are used in the process. The NMOS device is formed in a retrograde well while the PMOS device is fabricated directly in the high-resistivity silicon. Isolation characteristics are similar to a standard foundary CMOS process. Circuit performance using 3 μm design rules has been evaluated. The measured propagation delay and power-delay product for a 51-stage ring oscillator was 1.5 ns and 43 fJ, respectively. Measurements on a simple cascode amplifier results in a gain-bandwidth product of 200 MHz at a bias current of 15 μA. The input-referred noise of the cascode amplifier is 20 nV/√Hz at 1 MHz

  17. High-voltage electron-microscopical observation of crack-tip dislocations in silicon crystals

    International Nuclear Information System (INIS)

    Tanaka, Masaki; Higashida, Kenji

    2005-01-01

    Crack-tip dislocations in silicon single crystals were observed by high-voltage electron microscopy. Cracks were introduced into silicon wafers at room temperature by a Vickers indenter. The indented specimens were annealed at 823 K in order to activate dislocation emission from the crack tip under the residual stress due to the indentation. In the specimen without annealing, no dislocations were observed around the crack. On the other hand, in the specimen after the annealing, the aspect of the early stage of dislocation emission was observed, where dislocations were emitted not as a perfect dislocation but as a partial dislocation in the hinge-type plastic zone. Prominent dislocation arrays that were emitted from a crack tip were also observed, and they were found to be of shielding type, which increases the fracture toughness of those crystals

  18. Variation of minority charge carrier lifetime in high-resistance p-type silicon under irradiation

    International Nuclear Information System (INIS)

    Basheleishvili, Z.V.; Garnyk, V.S.; Gorin, S.N.; Pagava, T.A.

    1984-01-01

    The minority carrier lifetime (tau) variation was studied in the process of p-type silicon bombardment with fast 8 MeV electrons. The irradiation and all measurements were carried out at room temperature. The tau quantity was measured by the photoconductivity attenuation method at a low injection level 20% measurement error; the resistivity was measured by the four-probe method (10% error). The resistivity and minority charge carrier lifetime tau are shown to increase with the exposure dose. It is supposed that as radiation dose increases, the rearrangement of the centres responsible for reducing the lifetime occurs and results in a tau increase in the material being irradiated, however the tau value observed in the original samples is not attained. The restoration of the minority carrier lifetime in p-type high-resistance silicon with a growing exposure dose might proceed due to reduction in the free carrier concentration

  19. PECVD deposition of device-quality intrinsic amorphous silicon at high growth rate

    Energy Technology Data Exchange (ETDEWEB)

    Carabe, J [Inst. de Energias Renovables, CIEMAT, Madrid (Spain); Gandia, J J [Inst. de Energias Renovables, CIEMAT, Madrid (Spain); Gutierrez, M T [Inst. de Energias Renovables, CIEMAT, Madrid (Spain)

    1993-11-01

    The combined influence of RF-power density (RFP) and silane flow-rate ([Phi]) on the deposition rate of plasma-enhanced chemical vapour deposition (PECVD) intrinsic amorphous silicon has been investigated. The correlation of the results obtained from the characterisation of the material with the silane deposition efficiency, as deduced from mass spectrometry, has led to an interpretation allowing to deposit intrinsic amorphous-silicon films having an optical gap of 1.87 eV and a photoconductive ratio (ratio of ambient-temperature conductivities under 1 sun AM1 and in dark) of 6 orders of magnitude at growth rates up to 10 A/s, without any structural modification of the PECVD system used. Such results are considered of high relevance regarding industrial competitiveness. (orig.)

  20. Radiation hardness of silicon detectors - a challenge from high-energy physics

    CERN Document Server

    Lindström, G; Fretwurst, E

    1999-01-01

    An overview of the radiation-damage-induced problems connected with the application of silicon particle detectors in future high-energy physics experiments is given. Problems arising from the expected hadron fluences are summarized and the use of the nonionizing energy loss for normalization of bulk damage is explained. The present knowledge on the deterioration effects caused by irradiation is described leading to an appropriate modeling. Examples are given for a correlation between the change in the macroscopic performance parameters and effects to be seen on the microscopic level by defect analysis. Finally possible ways are out-lined for improving the radiation tolerance of silicon detectors either by operational conditions, process technology or defect engineering.

  1. High-silicon 238PuO2 fuel characterization study: Half module impact tests

    International Nuclear Information System (INIS)

    Reimus, M.A.H.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of [sup 238]Pu decay to an array of thermoelectric elements. The modular GPHS design was developed to address both survivability during launch abort and return from orbit. Previous testing conducted in support of the Galileo and Ulysses missions documented the response of GPHSs to a variety of fragment- impact, aging, atmospheric reentry, and Earth-impact conditions. The evaluations documented in this report are part of an ongoing program to determine the effect of fuel impurities on the response of the heat source to conditions baselined during the Galileo/Ulysses test program. In the first two tests in this series, encapsulated GPHS fuel pellets containing high levels of silicon were aged, loaded into GPHS module halves, and impacted against steel plates. The results show no significant differences between the response of these capsules and the behavior of relatively low-silicon fuel pellets tested previously

  2. Selective tuning of high-Q silicon photonic crystal nanocavities via laser-assisted local oxidation.

    Science.gov (United States)

    Chen, Charlton J; Zheng, Jiangjun; Gu, Tingyi; McMillan, James F; Yu, Mingbin; Lo, Guo-Qiang; Kwong, Dim-Lee; Wong, Chee Wei

    2011-06-20

    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 μm 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 Qs decreases from 3.2×10(5) to 1.2×10(5). Numerical simulations model the temperature distributions in the silicon photonic crystal membrane and the cavity resonance shift from oxidation.

  3. Improved contact metallization for high efficiency EFG polycrystalline silicon solar cells

    International Nuclear Information System (INIS)

    Dube, C.E.; Gonsiorawski, R.C.

    1990-01-01

    Improvements in the performance of polycrystalline silicon solar cells based on a novel, laser patterned contact process are described. Small lots of cells having an average conversion efficiency of 14 + %, with several cells approaching 15%, are reported for cells of 45 cm 2 area. The high efficiency contact design is based on YAG laser patterning of the silicon nitride anti-reflection coating. The Cu metallization is done using light-induced plating, with the cell providing the driving voltage for the plating process. The Cu electrodeposits into the laser defined windows in the AR coating for reduced contact area, following which the Cu bridges on top of the Ar coating to form a continuous finger pattern. The higher cell conversion efficiency is attributed to reduced shadow loss, higher junction quality, and reduced metal-semiconductor interfacial area

  4. Some considerations on silicone oil in high-current and energy-disconnecting mechanisms

    International Nuclear Information System (INIS)

    Vogel, H.F.

    1984-03-01

    Silicone oil is considered inflammable. The dissociation products generated by an electric arc under silicone oil are known to form a highly explosive mixture with air. We calculate the arc energy required for dissociation to be 32 kJ per liter of gas mixture at standard pressure and temperature. We calculate the arc voltage gradient at a pressure of 50 atm and current density of 1 kA/mm 2 to be 0.5 kV/cm, resulting in an arc voltage of several kV, depending on the arc length. In a multikiloampere arc, the resulting arc power is likely to cause a pressure of many atmospheres in a shock wave

  5. High Temperature All Silicon-Carbide (SiC) DC Motor Drives for Venus Exploration Vehicles, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project seeks to prove the feasibility of creating high-temperature silicon-carbide (SiC) based motor drives for...

  6. A silicon-based electrochemical sensor for highly sensitive, specific, label-free and real-time DNA detection

    International Nuclear Information System (INIS)

    Guo, Yuanyuan; Su, Shao; Wei, Xinpan; Zhong, Yiling; Su, Yuanyuan; He, Yao; Huang, Qing; Fan, Chunhai

    2013-01-01

    We herein present a new kind of silicon-based electrochemical sensor using a gold nanoparticles-decorated silicon wafer (AuNPs@Si) as a high-performance electrode, which is facilely prepared via in situ AuNPs growth on a silicon wafer. Particularly significantly, the resultant electrochemical sensor is efficacious for label-free DNA detection with high sensitivity due to the unique merits of the prepared silicon-based electrode. Typically, DNA at remarkably low concentrations (1–10 fM) could be readily detected without requiring additional signal-amplification procedures, which is better than or comparable to the lowest DNA concentration ever detected via well-studied signal-amplification-assisted electrochemical sensors. Moreover, the silicon-based sensor features high specificity, allowing unambiguous discrimination of single-based mismatches. We further show that real-time DNA assembly is readily monitored via recording the intensity changes of current signals due to the robust thermal stability of the silicon-based electrode. The unprecedented advantages of the silicon-based electrochemical sensor would offer new opportunities for myriad sensing applications. (paper)

  7. High temperature dielectric function of silicon, germanium and GaN

    Energy Technology Data Exchange (ETDEWEB)

    Leyer, Martin; Pristovsek, Markus; Kneissl, Michael [Technische Universitaet Berlin (Germany). Institut fuer Festkoerperphysik

    2010-07-01

    In the last few years accurate values for the optical properties of silicon, germanium and GaN at high temperatures have become important as a reference for in-situ analysis, e.g. reflectometry. Precise temperature dependent dielectric measurements are necessary for the growth of GaInP/GaInAs/Ge triple-junction solar cells and the hetero epitaxy of GaN on silicon and sapphire. We performed spectroscopic ellipsometry (SE) measurements of the dielectric function of silicon, germanium and GaN between 1.5 eV and 6.5 eV in the temperature range from 300 K to 1300 K. The Samples were deoxidized chemically or by heating. High resolution SE spectra were taken every 50 K while cooling down to room temperature. The temperature dependence of the critical energies is compared to literature. Measurements for germanium showed a shift of the E{sub 2} critical point of {proportional_to}0.1 eV toward lower energies. The reason for this behavior is a non-negligible oxide layer on the samples in the literature.

  8. Investigation on the improved radiation hardness of silicon detectors with high oxygen concentration

    CERN Document Server

    Moll, Michael; Lindström, G

    2000-01-01

    We present an investigation on the influence of the oxygen concentration on radiation-induced changes in the effective doping concentration of silicon detectors. Diodes fabricated from silicon with interstitial oxygen content ranging from below 2*10/sup 14/ to 9*10/sup 17/ cm/sup -3/ have been irradiated with fast neutrons up to a fluence of 2*10/sup 15/ cm/sup -2/. Our main interest focused on the so-called stable damage component in the change of the effective doping concentration being of prime importance for the application of silicon detectors in high-energy physics experiments. We demonstrate, that with a high oxygen enrichment the donor removal is appreciably reduced, reaching a value of only 10601130f the initial doping concentration for [O/sub i/]=9*10/sup 17/ cm/sup -3/, while for normal detector grade material with [O/sub i/] below 5*10/sup 16/ cm /sup -3/ that value is 60-90Furthermore, we show that the fluence proportional introduction of stable acceptors is independent of the oxygen concentratio...

  9. Advanced Packaging Technology Used in Fabricating a High-Temperature Silicon Carbide Pressure Sensor

    Science.gov (United States)

    Beheim, Glenn M.

    2003-01-01

    The development of new aircraft engines requires the measurement of pressures in hot areas such as the combustor and the final stages of the compressor. The needs of the aircraft engine industry are not fully met by commercially available high-temperature pressure sensors, which are fabricated using silicon. Kulite Semiconductor Products and the NASA Glenn Research Center have been working together to develop silicon carbide (SiC) pressure sensors for use at high temperatures. At temperatures above 850 F, silicon begins to lose its nearly ideal elastic properties, so the output of a silicon pressure sensor will drift. SiC, however, maintains its nearly ideal mechanical properties to extremely high temperatures. Given a suitable sensor material, a key to the development of a practical high-temperature pressure sensor is the package. A SiC pressure sensor capable of operating at 930 F was fabricated using a newly developed package. The durability of this sensor was demonstrated in an on-engine test. The SiC pressure sensor uses a SiC diaphragm, which is fabricated using deep reactive ion etching. SiC strain gauges on the surface of the diaphragm sense the pressure difference across the diaphragm. Conventionally, the SiC chip is mounted to the package with the strain gauges outward, which exposes the sensitive metal contacts on the chip to the hostile measurement environment. In the new Kulite leadless package, the SiC chip is flipped over so that the metal contacts are protected from oxidation by a hermetic seal around the perimeter of the chip. In the leadless package, a conductive glass provides the electrical connection between the pins of the package and the chip, which eliminates the fragile gold wires used previously. The durability of the leadless SiC pressure sensor was demonstrated when two 930 F sensors were tested in the combustor of a Pratt & Whitney PW4000 series engine. Since the gas temperatures in these locations reach 1200 to 1300 F, the sensors were

  10. A multi-institutional study exploring the impact of positive mental health on medical students' professionalism in an era of high burnout.

    Science.gov (United States)

    Dyrbye, Liselotte N; Harper, William; Moutier, Christine; Durning, Steven J; Power, David V; Massie, F Stanford; Eacker, Anne; Thomas, Matthew R; Satele, Daniel; Sloan, Jeff A; Shanafelt, Tait D

    2012-08-01

    Although burnout is associated with erosion of professionalism and serious personal consequences, whether positive mental health can enhance professionalism and how it shapes personal experience remain poorly understood. The study simultaneously explores the relationship between positive mental health and burnout with professionalism and personal experience. The authors surveyed 4,400 medical students at seven U.S. medical schools in 2009 to assess mental health (categorized as languishing, moderate, and flourishing) and burnout. Additional items explored professional behaviors, beliefs, suicidal ideation, and serious thoughts of dropping out. A total of 2,682/4,400 (61%) responded. Prevalence of suicidal ideation (55/114 [48.2%], 281/1,128 [24.9%], and 127/1,409 [9.1%]) and serious thoughts of dropping out (15/114 [13.2%], 30/1,128 [2.7%], and 14/1,409 [1.0%]) decreased as mental health improved from languishing, moderate, and flourishing, respectively (all P mental health persisted independent of burnout (all P mental health improved, the prevalence of unprofessional behaviors (i.e., cheating and dishonest behaviors) also declined, whereas students' altruistic beliefs regarding physicians' responsibility toward society improved. For example, 33/113 (29.2%), 426/1,120 (38.0%), and 718/1,391 (51.6%) of students with languishing, moderate, and flourishing mental health endorsed all five altruistic professional beliefs (P mental health persisted among students with burnout, whereas fewer relationships were found among students without burnout. Findings suggest that positive mental health attenuates some adverse consequences of burnout. Medical student wellness programs should aspire to prevent burnout and promote mental health.

  11. Determinants and prevalence of burnout in emergency nurses: a systematic review of 25 years of research.

    Science.gov (United States)

    Adriaenssens, Jef; De Gucht, Véronique; Maes, Stan

    2015-02-01

    Burnout is an important problem in health care professionals and is associated with a decrease in occupational well-being and an increase in absenteeism, turnover and illness. Nurses are found to be vulnerable to burnout, but emergency nurses are even more so, since emergency nursing is characterized by unpredictability, overcrowding and continuous confrontation with a broad range of diseases, injuries and traumatic events. This systematic review aims (1) to explore the prevalence of burnout in emergency nurses and (2) to identify specific (individual and work related) determinants of burnout in this population. A systematic review of empirical quantitative studies on burnout in emergency nurses, published in English between 1989 and 2014. The databases NCBI PubMed, Embase, ISI Web of Knowledge, Informa HealthCare, Picarta, Cinahl and Scielo were searched. Seventeen studies were included in this review. On average 26% of the emergency nurses suffered from burnout. Individual factors such as demographic variables, personality characteristics and coping strategies were predictive of burnout. Work related factors such as exposure to traumatic events, job characteristics and organizational variables were also found to be determinants of burnout in this population. Burnout rates in emergency nurses are high. Job demands, job control, social support and exposure to traumatic events are determinants of burnout, as well as several organizational variables. As a consequence specific action targets for hospital management are formulated to prevent turnover and burnout in emergency nurses. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Measurement of the drift velocities of electrons and holes in high-ohmic silicon

    International Nuclear Information System (INIS)

    Scharf, Christian

    2014-02-01

    Measurements of the drift velocities of electrons and holes as a function of the electric field and the temperature in high-ohmic silicon of crystal orientation are presented. Significant differences between our results and literature values are observed. A new parametrization of the mobility is introduced. Current transients of n-type pad diodes, generated by fast laser pulses, were investigated in order to determine the drift velocity of electrons and holes separately. Two diodes of high-ohmic silicon (1.5 kΩcm and 5.5 kΩcm) from different manufacturers were investigated as cross check. The drift velocities were determined at electric fields ranging from 5 kV/cm to 50 kV/cm at temperatures ranging from 233 K to 333 K. The mobility parameters were obtained by fitting a simulation of charge drift in silicon to the measurements. Using the convolution theorem the response function of the read-out circuit was determined with the Fourier transforms of the measurement and the simulation. The simulated transient current pulses with the new mobility parametrization are consistent with the measured ones for the temperature and electric field range investigated here. Additionally, the mobility results from the fit are consistent with the mobility determined using the simpler time-of-flight method in the field range where this method is applicable. However, our measurements show a difference of up to 14 % to the values by Canali et al. (1971). The difference to the mobility parametrization by Jacoboni et al. (1977) is up to 24 % while this parametrization is widely used for simulations of the direction due to the lack of data for silicon.

  13. Silicon solar cells with high efficiencies. Final report; Silicium-Solarzellen mit hoechsten Wirkungsgraden. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Wettling, W.; Knobloch, J.; Glunz, S.W.; Henninger, V.; Kamerewerd, F.J.; Koester, B.; Leimenstoll, A.; Schaeffer, E.; Schumacher, J.; Sterk, S.; Warta, W.

    1996-06-01

    In this report the basic activities for the development of the silicon high efficiency solar cell technology are described. The project had two main goals: (i) The improvement of efficiencies using a systematic optimization of all cell parameters and technology steps and (ii) the simplification of the technology towards the possibilities of an industrial production, keeping the cell efficiency at a high level. Starting from the LBSF technology, developed at Fraunhofer ISE, the reduction of all loss mechanisms led to efficiencies up to 22.5% on FZ-silicon. Using a modification of this technology efficiencies of up to 21.7% have been reached on Cz-silicon. Even after the reduction of the number of photolithographic steps from six to three efficiencies up to 21.6% on FZ- and 19.5% on Cz-silicon have been obtained. These are best values in an international comparison. (orig.) [Deutsch] In diesem Projektbericht werden grundlegende Arbeiten zur Entwicklung der Silicium-`Highefficiency`-Solarzellentechnologie beschrieben. Das Projekt hatte zwei Hauptziele: (i) Die Erhoehung der Wirkungsgrade durch eine systematische Optimierung aller Zellparameter und aller Technologieschritte und (ii) die Vereinfachung der Technologie unter Beibehaltung sehr hoher Wirkungsgrade mit dem Ziel einer Annaeherung an die Moeglichkeiten der Industriefertigung. Ausgehend von der im Fraunhofer ISE entwickelten LBSF-Technologie gelang es durch Reduzierung aller Verlustmechanismen, Wirkungsgrade bis zu 22.5% auf FZ-Silicium zu erreichen. Nach Anpassung der Technologie wurden auf Cz-Silicium Wirkungsgrade bis 21.7% erzielt. Ein von sechs auf drei Fotomaskenschritte reduzierter Prozess erzielte immerhin noch Werte bis 21.6% auf FZ- und 19.5% auf Cz-Material. Alle dieser Werte stellen im internationalen Vergleich Spitzenleistungen dar. (orig.)

  14. Highly nonlinear sub-micron silicon nitride trench waveguide coated with gold nanoparticles

    Science.gov (United States)

    Huang, Yuewang; Zhao, Qiancheng; Sharac, Nicholas; Ragan, Regina; Boyraz, Ozdal

    2015-05-01

    We demonstrate the fabrication of a highly nonlinear sub-micron silicon nitride trench waveguide coated with gold nanoparticles for plasmonic enhancement. The average enhancement effect is evaluated by measuring the spectral broadening effect caused by self-phase-modulation. The nonlinear refractive index n2 was measured to be 7.0917×10-19 m2/W for a waveguide whose Wopen is 5 μm. Several waveguides at different locations on one wafer were measured in order to take the randomness of the nanoparticle distribution into consideration. The largest enhancement is measured to be as high as 10 times. Fabrication of this waveguide started with a MEMS grade photomask. By using conventional optical lithography, the wide linewidth was transferred to a wafer. Then the wafer was etched anisotropically by potassium hydroxide (KOH) to engrave trapezoidal trenches with an angle of 54.7º. Side wall roughness was mitigated by KOH etching and thermal oxidation that was used to generate a buffer layer for silicon nitride waveguide. The guiding material silicon nitride was then deposited by low pressure chemical vapor deposition. The waveguide was then patterned with a chemical template, with 20 nm gold particles being chemically attached to the functionalized poly(methyl methacrylate) domains. Since the particles attached only to the PMMA domains, they were confined to localized regions, therefore forcing the nanoparticles into clusters of various numbers and geometries. Experiments reveal that the waveguide has negligible nonlinear absorption loss, and its nonlinear refractive index can be greatly enhanced by gold nano clusters. The silicon nitride trench waveguide has large nonlinear refractive index, rendering itself promising for nonlinear applications.

  15. Silicon-Polymer Encapsulation of High-Level Calcine Waste for Transportation or Disposal

    International Nuclear Information System (INIS)

    Loomis, G.G.; Miller, C.M.; Giansiracusa, J.A.; Kimmel, R.; Prewett, S.V.

    2000-01-01

    This report presents the results of an experimental study investigating the potential uses for silicon-polymer encapsulation of High Level Calcine Waste currently stored within the Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Engineering and Environmental Laboratory (INEEL). The study investigated two different applications of silicon polymer encapsulation. One application uses silicon polymer to produce a waste form suitable for disposal at a High Level Radioactive Waste Disposal Facility directly, and the other application encapsulates the calcine material for transportation to an offsite melter for further processing. A simulated waste material from INTEC, called pilot scale calcine, which contained hazardous materials but no radioactive isotopes was used for the study, which was performed at the University of Akron under special arrangement with Orbit Technologies, the originators of the silicon polymer process called Polymer Encapsulation Technology (PET). This document first discusses the PET process, followed by a presentation of past studies involving PET applications to waste problems. Next, the results of an experimental study are presented on encapsulation of the INTEC calcine waste as it applies to transportation or disposal of calcine waste. Results relating to long-term disposal include: (1) a characterization of the pilot calcine waste; (2) Toxicity Characteristic Leaching Procedure (TCLP) testing of an optimum mixture of pilot calcine, polysiloxane and special additives; and, (3) Material Characterization Center testing MCC-1P evaluation of the optimum waste form. Results relating to transportation of the calcine material for a mixture of maximum waste loading include: compressive strength testing, 10-m drop test, melt testing, and a Department of Transportation (DOT) oxidizer test

  16. 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.

  17. BURNOUT AND OCCUPATIONAL PARTICIPATION

    Science.gov (United States)

    Eren, Hakan; Huri, Meral; Bağış, Nilsun; Başıbüyük, Onur; Şahin, Sedef; Umaroğlu, Mutlu; Orhan, Kaan

    2016-11-01

    The aim of the present study was to investigate the prevalence of burnout and occupational participation limitation among dental students in a dental school in Turkey. Four hundred fifty-eight dental students (females=153; males=305) were included in the study. The age range varied from 17-to-38 years. Maslach Burnout Inventory-Student Version (MBI-SV) and Canadian Occupational Performance Measure (COPM) were used to gather data. Descriptive analyses, t-test, and Kruskall-Wallis test for independent groups were used for data analyses. The results indicated that 26% of all the students have burnout in terms of emotional exhaustion (25%), cynicism (18%), and academic efficacy (14%). The results showed that burnout is statistically significant in relation to demographics (pstudents showed considerably decreased occupational performance and satisfaction scores, which suggested occupational participation limitations. Occupational performance and satisfaction scores were inversely correlated with emotional exhaustion and cynicism, while directly correlated with reduced academic efficacy (pburnout and occupational participation limitation can be seen among dental students. Students with burnout may also have occupational participation limitation. Enriching dental education programs with different psychological strategies may be useful for education of healthy dentists and improve the quality of oral and dental health services.

  18. Burnout and Associated Factors among Iranian Emergency Medicine Practitioners.

    Science.gov (United States)

    Jalili, Mohammad; Sadeghipour Roodsari, Gholamreza; Bassir Nia, Anahita

    2013-09-01

    Emergency physicians are at risk of burnout, which can affect their mental health, as well as patient care. We assessed burnout level among Iranian emergency physicians and investigated demographic, work-related factors and stressors associated with higher burnout. In a cross-sectional study, we surveyed all 188 emergency medicine residents and practitioners in Iran. We measured burnout using 22-item Maslach Burnout Inventory assessing emotional exhaustion, depersonalization and personal accomplishment, also demographic factors, work related factors and sources of stress in emergency department using anonymous self-administered questionnaire. Descriptive analysis, univariate analysis to evaluate association with higher score of burnout, and multivariate logistic regression analysis to predict high burnout in 3 subscales was performed. Totally, 165 questionnaires were filled (response rate: 88%; mean age: 33.6 years, 91% male). Mean burnout scores were 22.94 for emotional exhaustion (95% CI=20.78-25.01; moderate), 9.3 for depersonalization (95% CI=8.24-10.36; moderate to high), and 31.47 for personal accomplishment (95% CI=29.87-33.07; moderate to high). Frequent reported sources of stress were shortage of equipment, problem with work physical environment, and relationship with other services. All 19 sources of stress were associated with higher score of emotional exhaustion and depersonalization; while twelve out of 19 were significantly associated with lower level of personal accomplishment. In logistic regression model, the significant predictors for high emotional exhaustion were work overload, feeling of insecurity for future career and difficulties to balance professional and private life. Burnout is high among Iranian emergency medicine practitioners and some interventions can be proposed to reduce stress.

  19. [Burnout and perceived health in Critical Care nursing professionals].

    Science.gov (United States)

    Ríos Risquez, M I; Peñalver Hernández, F; Godoy Fernández, C

    2008-01-01

    To assess the level of burnout syndrome in a sample of critical care nursing professionals and analyze its relation with the perception of general health and other sociodemographic and work characteristics. Cross-sectional descriptive study. SITE: Intensive Care Unit of the University Hospital Morales Meseguer, Murcia-Spain. Three evaluation tools were used. These included a sociodemographic and work survey, the validated Maslach Burnout Inventory (MBI) questionnaires and the General Health Questionnaire (GHQ-28) in order to assess professional burnout and the general health condition perceived, respectively. Only 42 out of the 56 questionnaires included in the study were valid. This means an answering rate of 75%. The mean score obtained on the emotional tiredness dimension (25.45 6 11.15) stands out. About 42.9% of the sample presented psychological or psychosomatic symptoms that could require specialized care. Correlation between burnout and general health perception was statistically significant (r = 0.536; p burnout found was moderate to high among critical care nursing professionals. A total of 11.9% of the studied sample had a high score in the 3 dimensions of the burnout syndrome: emotional tiredness, depersonalization, and lack of personal job performance. Burnout and health levels found indicate high vulnerability in the sample studied and the need to establish prevention/intervention programs in this work context.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Influence for high intensity irradiation on characteristics of silicon strip-detectors

    International Nuclear Information System (INIS)

    Anokhin, I.E.; Pugatch, V.M.; Zinets, O.S.

    1995-01-01

    Full text: Silicon strip detectors (SSD) are widely used for the coordinate determination of short-range as well as minimum ionizing particles with high spatial resolution. Submicron position sensitivity of strip-detectors for short-range particles has been studied by means of two dimensional analyses of charges collected by neighboring strips as well as by measurement of charge collection times [1]. Silicon strip detectors was also used for testing high energy electron beam [2]. Under large fluences the radiation defects are stored and such characteristics of strip-detectors as an accuracy of the coordinate determination and the registration efficiency are significantly changed. Radiation defects lead to a decrease of the lifetime and mobility of charge carriers and therefore to changes of conditions for the charge collection in detectors. The inhomogeneity in spatial distribution if defects and electrical field plays an important role in the charge collection. In this report the role of the diffusion and drift in the charge collection in silicon strip-detectors under irradiation up to 10 Mrad has been studied. The electric field distribution and its dependence on the radiation dose in the detector have been calculated. It is shown that for particles incident between adjacent strips the coordinate determination precision depends strongly on the detector geometry and the electric field distribution, particularly in the vicinity of strips. Measuring simultaneously the collected charges and collection times on adjacent strips one can essentially improve reliability of the coordinate determination for short-range particles. Usually SSD are fabricated on n-type wafers. It is well known that under high intensity irradiation n-Si material converts into p-Si as far as p-type silicon is more radiative hard than n-type silicon [3] it is reasonable to fabricate SSD using high resistivity p-Si. Characteristics of SSD in basis n-and P-Si have been compared and higher

  5. From Burnout to Wellness: A Professional Imperative.

    Science.gov (United States)

    Golub, Justin S; Johns, Michael M

    2018-03-01

    Professional burnout is a barrier to physician wellness. Burnout is prevalent across medicine, and otolaryngology as a specialty ranks near the mean. We review burnout levels in various subgroups of otolaryngology, including academic chairs, faculty, and residents. Risk factors of burnout are discussed, which differ by subgroup. Finally, we propose measures that could help minimize burnout and promote healthy and satisfying careers.

  6. Silicon homo-heterojunction solar cells: A promising candidate to realize high performance more stably

    Directory of Open Access Journals (Sweden)

    Miao Tan

    2017-08-01

    Full Text Available We have investigated the influences of diverse physical parameters on the performances of a silicon homo-heterojunction (H-H solar cell, which encompasses both homojunction and heterojunction, together with their underlying mechanisms by the aid of AFORS-HET simulation. It is found that the performances of H-H solar cell are less sensitive to (i the work function of the transparent conductive oxide layer, (ii the interfacial density of states at the front hydrogenated amorphous silicon/crystalline silicon (a-Si:H/c-Si interface, (iii the peak dangling bond defect densities within the p-type a-Si:H (p-a-Si:H layer, and (iv the doping concentration of the p-a-Si:H layer, when compared to that of the conventional heterojunction with intrinsic thin layer (HIT counterparts. These advantages are due to the fact that the interfacial recombination and the recombination within the a-Si:H region are less affected by all the above parameters, which fundamentally benefit from the field-effect passivation of the homojunction. Therefore, the design of H-H structure can provide an opportunity to produce high-efficiency solar cells more stably.

  7. NLTE ANALYSIS OF HIGH-RESOLUTION H -BAND SPECTRA. I. NEUTRAL SILICON

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Junbo; Shi, Jianrong; Liu, Chao [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, A20 Datun Road, Chaoyang District, Beijing 100012 (China); Pan, Kaike [Apache Point Observatory and New Mexico State University, P.O. Box 59, Sunspot, NM, 88349-0059 (United States); Prieto, Carlos Allende, E-mail: sjr@bao.ac.cn [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain)

    2016-12-20

    We investigated the reliability of our silicon atomic model and the influence of non-local thermodynamical equilibrium (NLTE) on the formation of neutral silicon (Si i) lines in the near-infrared (near-IR) H -band. We derived the differential Si abundances for 13 sample stars with high-resolution H -band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE), as well as from optical spectra, both under local thermodynamical equilibrium (LTE) and NLTE conditions. We found that the differences between the Si abundances derived from the H -band and from optical lines for the same stars are less than 0.1 dex when the NLTE effects are included, and that NLTE reduces the line-to-line scatter in the H -band spectra for most sample stars. These results suggest that our Si atomic model is appropriate for studying the formation of H -band Si lines. Our calculations show that the NLTE corrections of the Si i H -band lines are negative, i.e., the final Si abundances will be overestimated in LTE. The corrections for strong lines depend on surface gravity, and tend to be larger for giants, reaching ∼−0.2 dex in our sample, and up to ∼−0.4 dex in extreme cases of APOGEE targets. Thus, the NLTE effects should be included in deriving silicon abundances from H -band Si i lines, especially for the cases where only strong lines are available.

  8. Fabrication of silicon-embedded low resistance high-aspect ratio planar copper microcoils

    Science.gov (United States)

    Syed Mohammed, Zishan Ali; Puiu, Poenar Daniel; Aditya, Sheel

    2018-01-01

    Low resistance is an important requirement for microcoils which act as a signal receiver to ensure low thermal noise during signal detection. High-aspect ratio (HAR) planar microcoils entrenched in blind silicon trenches have features that make them more attractive than their traditional counterparts employing electroplating through a patterned thick polymer or achieved through silicon vias. However, challenges met in fabrication of such coils have not been discussed in detail until now. This paper reports the realization of such HAR microcoils embedded in Si blind trenches, fabricated with a single lithography step by first etching blind trenches in the silicon substrate with an aspect ratio of almost 3∶1 and then filling them up using copper electroplating. The electroplating was followed by chemical wet etching as a faster way of removing excess copper than traditional chemical mechanical polishing. Electrical resistance was further reduced by annealing the microcoils. The process steps and challenges faced in the realization of such structures are reported here followed by their electrical characterization. The obtained electrical resistances are then compared with those of other similar microcoils embedded in blind vias.

  9. Spontaneous layering of porous silicon layers formed at high current densities

    Energy Technology Data Exchange (ETDEWEB)

    Parkhutik, Vitali; Curiel-Esparza, Jorge; Millan, Mari-Carmen [R and D Center MTM, Technical University of Valencia, Valencia (Spain); Albella, Jose [Institute of Materials Science (ICMM CSIC) Madrid (Spain)

    2005-06-01

    We report here a curious effect of spontaneous fracturing of the silicon layers formed in galvanostatic conditions at medium and high current densities. Instead of formation of homogeneous p-Si layer as at low currents, a stack of thin layers is formed. Each layer is nearly separated from others and possesses rather flat interfaces. The effects is observed using p{sup +}-Si wafers for the p-Si formation and starts being noticeable at above 100 mA/cm{sup 2}. We interpret these results in terms of the porous silicon growth model where generation of dynamic mechanical stress during the p-Si growth causes sharp changes in Si dissolution mechanism from anisotropic etching of individual needle-like pores in silicon to their branching and isotropic etching. At this moment p-Si layer loses its adhesion to the surface of Si wafer and another p-Si layer starts growing. One of the mechanisms triggering on the separation of p-Si layers from one another is a fluctuation of local anodic current in the pore bottoms associated with gas bubble evolution during the p-Si formation. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Ultraviolet Plasmonic Aluminium Nanoparticles for Highly Efficient Light Incoupling on Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Yinan Zhang

    2016-05-01

    Full Text Available Plasmonic metal nanoparticles supporting localized surface plasmon resonances have attracted a great deal of interest in boosting the light absorption in solar cells. Among the various plasmonic materials, the aluminium nanoparticles recently have become a rising star due to their unique ultraviolet plasmonic resonances, low cost, earth-abundance and high compatibility with the complementary metal-oxide semiconductor (CMOS manufacturing process. Here, we report some key factors that determine the light incoupling of aluminium nanoparticles located on the front side of silicon solar cells. We first numerically study the scattering and absorption properties of the aluminium nanoparticles and the influence of the nanoparticle shape, size, surface coverage and the spacing layer on the light incoupling using the finite difference time domain method. Then, we experimentally integrate 100-nm aluminium nanoparticles on the front side of silicon solar cells with varying silicon nitride thicknesses. This study provides the fundamental insights for designing aluminium nanoparticle-based light trapping on solar cells.

  11. Silicon homo-heterojunction solar cells: A promising candidate to realize high performance more stably

    Science.gov (United States)

    Tan, Miao; Zhong, Sihua; Wang, Wenjie; Shen, Wenzhong

    2017-08-01

    We have investigated the influences of diverse physical parameters on the performances of a silicon homo-heterojunction (H-H) solar cell, which encompasses both homojunction and heterojunction, together with their underlying mechanisms by the aid of AFORS-HET simulation. It is found that the performances of H-H solar cell are less sensitive to (i) the work function of the transparent conductive oxide layer, (ii) the interfacial density of states at the front hydrogenated amorphous silicon/crystalline silicon (a-Si:H/c-Si) interface, (iii) the peak dangling bond defect densities within the p-type a-Si:H (p-a-Si:H) layer, and (iv) the doping concentration of the p-a-Si:H layer, when compared to that of the conventional heterojunction with intrinsic thin layer (HIT) counterparts. These advantages are due to the fact that the interfacial recombination and the recombination within the a-Si:H region are less affected by all the above parameters, which fundamentally benefit from the field-effect passivation of the homojunction. Therefore, the design of H-H structure can provide an opportunity to produce high-efficiency solar cells more stably.

  12. Highly efficient luminescent solar concentrators based on earth-abundant indirect-bandgap silicon quantum dots

    Science.gov (United States)

    Meinardi, Francesco; Ehrenberg, Samantha; Dhamo, Lorena; Carulli, Francesco; Mauri, Michele; Bruni, Francesco; Simonutti, Roberto; Kortshagen, Uwe; Brovelli, Sergio

    2017-02-01

    Building-integrated photovoltaics is gaining consensus as a renewable energy technology for producing electricity at the point of use. Luminescent solar concentrators (LSCs) could extend architectural integration to the urban environment by realizing electrode-less photovoltaic windows. Crucial for large-area LSCs is the suppression of reabsorption losses, which requires emitters with negligible overlap between their absorption and emission spectra. Here, we demonstrate the use of indirect-bandgap semiconductor nanostructures such as highly emissive silicon quantum dots. Silicon is non-toxic, low-cost and ultra-earth-abundant, which avoids the limitations to the industrial scaling of quantum dots composed of low-abundance elements. Suppressed reabsorption and scattering losses lead to nearly ideal LSCs with an optical efficiency of η = 2.85%, matching state-of-the-art semi-transparent LSCs. Monte Carlo simulations indicate that optimized silicon quantum dot LSCs have a clear path to η > 5% for 1 m2 devices. We are finally able to realize flexible LSCs with performances comparable to those of flat concentrators, which opens the way to a new design freedom for building-integrated photovoltaics elements.

  13. The relationship between teacher burnout and student motivation.

    Science.gov (United States)

    Shen, Bo; McCaughtry, Nate; Martin, Jeffrey; Garn, Alex; Kulik, Noel; Fahlman, Mariane

    2015-12-01

    Teacher burnout is regarded as a serious problem in school settings. To date, studies on teachers' stress and burnout have largely centred on teachers' own characteristics, socialization, and behaviours, but few have explored the connection between teachers' burnout and students' motivation via their own perceptions of teachers' behaviour and emotional well-being. This study adopted Maslach et al.'s (2001, Annu. Rev. Psychol., 52, 397) job burnout construct and self-determination theory to investigate the relationships between teachers' burnout and students' autonomous motivation over one-semester physical education classes. A total of 1,302 high school students and their 33 physical education teachers in 20 high schools from two school districts in a major Midwest metropolitan area in the United States. The two school districts were demographically similar. Students and physical education teachers completed questionnaires assessing relevant psychological constructs. There were two time points for collecting students' data. One was at the beginning of a fall semester, and the other was at the end of that semester. Hierarchical linear modelling analyses were conducted. It was revealed that teachers' emotional exhaustion was negatively related to students' perceived teacher autonomy support (TAS); in turn, there was a negative relationship between teachers' feeling of depersonalization and students' autonomous motivation development even when controlling for inadequate TAS. The dimensions of teachers' burnout might play different roles in the transmission from teachers to students. Teachers' status of burnout is an important environmental factor associated with students' quality of motivation. © 2015 The British Psychological Society.

  14. 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.

  15. 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.

  16. Burnout Among the Clinical Dental Students in the Jordanian Universities

    Science.gov (United States)

    Amin, Wala Majid; Al-Ali, Muna H.; Duaibis, Ramzi B.; Oweis, Tamara; Badran, Darwish H.

    2009-01-01

    Background The study aimed to evaluate the level of burnout among the clinical dental students in two Jordanian universities. Methods A total of 307 students from the two schools were surveyed using Maslach Burnout Inventory survey. Scores for the inventory’s subscales were calculated and the mean values for the students’ groups were computed separately. Kruskal-Wallis and Mann-Whitney tests were carried out and the results were compared at 95% confidence level. Results The results showed that the dental students in both Jordanian universities suffered high levels of emotional exhaustion and depersonalization compared to reported levels for dental students in other countries. The dental students of the University of Jordan demonstrated a significantly higher (p < 0.05) level of emotional exhaustion than their counterparts in the Jordan University of Science and Technology. Conclusions The findings indicated that dental students in the Jordanian universities presented considerable degrees of burnout manifested by high levels of emotional exhaustion and depersonalization. Studies targeting students health and psychology should be carried out to determine the causes of burnout among dental students. The curricula of the dental schools in the two universities should be accordingly improved to minimize burnout among the students. Keywords Burnout; Emotional exhaustion; Depersonalization; Personal accomplishment; Maslach Burnout Inventory PMID:22461870

  17. 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

    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. 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 1 st year. Data were analyzed independently as questionnaires were anonymized. We found that 1 st year of medical college showed a significantly increasing depression ( P stress ( 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 stress scores ( r = 0.210, P = 0.008). However, burnout did not correlate with any of the personality dimensions. Right from the 1 st 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.

  18. 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.

  19. A new soft dielectric silicone elastomer matrix with high mechanical integrity and low losses

    DEFF Research Database (Denmark)

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

    2015-01-01

    Though dielectric elastomers (DEs) have many favourable properties, the issue of high driving voltages limits the commercial viability of the technology. Driving voltage can be lowered by decreasing the Young's modulus and increasing the dielectric permittivity of silicone elastomers. A decrease...... in Young's modulus, however, is often accompanied by the loss of mechanical stability and thereby the lifetime of the DE. A new soft elastomer matrix, with no loss of mechanical stability and high dielectric permittivity, was prepared through the use of alkyl chloride-functional siloxane copolymers...

  20. Silicon photonic transceiver circuit for high-speed polarization-based discrete variable quantum key distribution.

    Science.gov (United States)

    Cai, Hong; Long, Christopher M; DeRose, Christopher T; Boynton, Nicholas; Urayama, Junji; Camacho, Ryan; Pomerene, Andrew; Starbuck, Andrew L; Trotter, Douglas C; Davids, Paul S; Lentine, Anthony L

    2017-05-29

    We demonstrate a silicon photonic transceiver circuit for high-speed discrete variable quantum key distribution that employs a common structure for transmit and receive functions. The device is intended for use in polarization-based quantum cryptographic protocols, such as BB84. Our characterization indicates that the circuit can generate the four BB84 states (TE/TM/45°/135° linear polarizations) with >30 dB polarization extinction ratios and gigabit per second modulation speed, and is capable of decoding any polarization bases differing by 90° with high extinction ratios.