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Sample records for stress scale pss

  1. Reliability and validity of Persian version of perceived stress scale (PSS-10) in adults with asthma.

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    Maroufizadeh, Saman; Zareiyan, Armin; Sigari, Naseh

    2014-05-01

    Asthma is a major public health problem in the world, and recent findings suggest that stress influences asthma and asthma morbidity. The 10-item Perceived Stress Scale (PSS-10) is one of the most frequently used instruments to measure psychological stress. This study was conducted to evaluate the psychometric properties of the Persian versions of the PSS-10 in adults with asthma. In this descriptive cross-sectional study as a methodological research, 106 asthmatic patients referring to several clinics in Sanandaj (western Iran) were selected through convenience sampling. The PSS-10 and the 21-item Depression anxiety and stress scale (DASS-21) were administrated to all patients. Cronbach's alpha was used to evaluate reliability of PSS-10, and confirmatory factor analysis (CFA) and convergent validity were used to evaluate its validity. The results of confirmatory factor analysis indicated that a two-factor structure of PSS-10 provided a good fit to data. The Cronbach's alpha coefficients for negative factor, positive factor and total score (PSS-10) were 0.86, 0.83, and 0.90, respectively. The PSS-10 was positively correlated with the DASS-21 and its subscales, indicating an acceptable convergent validity. Female asthmatic patients scored higher on PSS-10 in comparison with male asthmatic patients. The Persian version of PSS-10 is a valid and reliable instrument to measure perceived stress in adults with asthma.

  2. Determining Factors for Stress Perception Assessed with the Perceived Stress Scale (PSS-4) in Spanish and Other European Samples.

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    Vallejo, Miguel A; Vallejo-Slocker, Laura; Fernández-Abascal, Enrique G; Mañanes, Guillermo

    2018-01-01

    Objective: Stress perception depends on cultural and social aspects that vary from one country to another. One of the most widely disseminated methods of assessing psychological stress is the Perceived Stress Scale (PSS-4). Therefore, in order to identify these factors and their impact on mental health, the present study compares the PSS-4 results among three European countries (Great Britain, France and Spain). This study focuses on PSS-4 results within a Spanish sample to determine: (1) normative data, reliability and validity of PSS-4 in a Spanish sample and (2) how stress perception changes depending on cultural and social factors. Methods: The data were obtained from a website representing a service of a smoking cessation program, the study represented a service that was open to all individuals. The number of participants were 37,451. They reported their age, gender, nationality, marital status, education and employment status, and completed two psychological questionnaires (PPS-4 and the anxiety and depression scales of the Symptom Checklist-90-Revised, SCL 90-R). Results: The PSS-4 scores could differentiate between relevant sociodemographic variables (such as sex, age, nationality, marital status, education, parental status, employment status, and income class). The PSS-4 scores showed a positive correlation with the SCL 90-R anxiety and depression scales. The normed values for interpreting the PSS-4 scores are presented. The PSS-4 showed adequate internal consistency and reliability. Conclusions: The PSS-4 is a useful instrument for assessing stress perception levels in the general population in different countries. Its internal consistency is sufficient for a 4-item scale.

  3. Determining Factors for Stress Perception Assessed with the Perceived Stress Scale (PSS-4 in Spanish and Other European Samples

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    Miguel A. Vallejo

    2018-01-01

    Full Text Available Objective: Stress perception depends on cultural and social aspects that vary from one country to another. One of the most widely disseminated methods of assessing psychological stress is the Perceived Stress Scale (PSS-4. Therefore, in order to identify these factors and their impact on mental health, the present study compares the PSS-4 results among three European countries (Great Britain, France and Spain. This study focuses on PSS-4 results within a Spanish sample to determine: (1 normative data, reliability and validity of PSS-4 in a Spanish sample and (2 how stress perception changes depending on cultural and social factors.Methods: The data were obtained from a website representing a service of a smoking cessation program, the study represented a service that was open to all individuals. The number of participants were 37,451. They reported their age, gender, nationality, marital status, education and employment status, and completed two psychological questionnaires (PPS-4 and the anxiety and depression scales of the Symptom Checklist-90-Revised, SCL 90-R.Results: The PSS-4 scores could differentiate between relevant sociodemographic variables (such as sex, age, nationality, marital status, education, parental status, employment status, and income class. The PSS-4 scores showed a positive correlation with the SCL 90-R anxiety and depression scales. The normed values for interpreting the PSS-4 scores are presented. The PSS-4 showed adequate internal consistency and reliability.Conclusions: The PSS-4 is a useful instrument for assessing stress perception levels in the general population in different countries. Its internal consistency is sufficient for a 4-item scale.

  4. The Vietnamese version of the Perceived Stress Scale (PSS-10): Translation equivalence and psychometric properties among older women.

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    Dao-Tran, Tiet-Hanh; Anderson, Debra; Seib, Charrlotte

    2017-02-06

    The Perceived Stress Scale 10 item (PSS-10) has been translated into more than 20 languages and used widely in different populations. Yet, to date, no study has tested psychometric properties of the instrument among older women and there is no Vietnamese version of the instrument. This study translated the PSS-10 into Vietnamese and assessed Vietnamese version of the Perceived Stress Scale 10 items (V-PSS-10) for translation equivalence, face validity, construct validity, correlations, internal consistency reliability, and test-retest reliability among 473 women aged 60 and over. The study found that V-PSS-10 retained the original meaning and was understood by Vietnamese older women. An exploratory factor analysis of the V-PSS-10 yielded a two-factor structure, and these two factors were significantly correlated (0.56, p < .01) with all item loadings exceeded .50. The V-PSS-10 score was positively correlated with general sleep disturbance (ρ = .12, p < .05), CES-D score for depression symptoms (ρ = .60, p < .01), and negatively correlated with mental (ρ = -.46, p < .01), and physical health scores (ρ = -.19, p < .01). The Cronbach's alpha for the V-PSS-10 was .80, and the test-retest correlation at one month's interval was .43. Findings from this study suggest that the V-PSS-10 has acceptable validity and reliability levels among older women. The V-PSS-10 can be used to measure perceived stress in future research and practice. However, future research would be useful to further endorse the validity and reliability of the V-PSS-10.

  5. Psychometric properties of the Perceived Stress Scale (PSS: measurement invariance between athletes and non-athletes and construct validity

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    Yi-Hsiang Chiu

    2016-12-01

    Full Text Available Background Although Perceived Stress Scale (PSS, Cohen, Kamarack & Mermelstein, 1983 has been validated and widely used in many domains, there is still no validation in sports by comparing athletes and non-athletes and examining related psychometric indices. Purpose The purpose of this study was to examine the measurement invariance of PSS between athletes and non-athletes, and examine construct validity and reliability in the sports contexts. Methods Study 1 sampled 359 college student-athletes (males = 233; females = 126 and 242 non-athletes (males = 124; females = 118 and examined factorial structure, measurement invariance and internal consistency. Study 2 sampled 196 student-athletes (males = 139, females = 57, Mage = 19.88 yrs, SD = 1.35 and examined discriminant validity and convergent validity of PSS. Study 3 sampled 37 student-athletes to assess test-retest reliability of PSS. Results Results found that 2-factor PSS-10 fitted the model the best and had appropriate reliability. Also, there was a measurement invariance between athletes and non-athletes; and PSS positively correlated with athletic burnout and life stress but negatively correlated with coping efficacy provided evidence of discriminant validity and convergent validity. Further, the test-retest reliability for PSS subscales was significant (r = .66 and r = .50. Discussion It is suggested that 2-factor PSS-10 can be a useful tool in assessing perceived stress either in sports or non-sports settings. We suggest future study may use 2-factor PSS-10 in examining the effects of stress on the athletic injury, burnout, and psychiatry disorders.

  6. The Malay Version of the Perceived Stress Scale (PSS)-10 is a Reliable and Valid Measure for Stress among Nurses in Malaysia.

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    Sandhu, Sukhvinder Singh; Ismail, Noor Hassim; Rampal, Krishna Gopal

    2015-11-01

    The Perceived Stress Scale-10 (PSS-10) is widely used to assess stress perception. The aim of this study was to translate the original PSS-10 into Malay and assess the reliability and validity of the Malay version among nurses. The Malay version of the PSS-10 was distributed among 229 nurses from four government hospitals in Selangor State. Test-retest reliability and concurrent validity was conducted with 25 nurses with the Malay version of the Depression Anxiety Stress Scales (DASS) 21. Cronbach's alpha, confirmatory factor analysis (CFA), intraclass correlation coefficient and Pearson's r correlation coefficient were used to determine the psychometric properties of the Malay PSS-10. Two factor components were yielded through exploratory factor analysis with eigenvalues of 3.37 and 2.10, respectively. Both of the factors accounted for 54.6% of the variance. CFA yielded a two-factor structure with satisfactory goodness-of-fit indices [x 2 /df = 2.43; comparative fit index (CFI) = 0.92, goodness-of-fit Index (GFI) = 0.94; standardised root mean square residual (SRMR) = 0.07 and root mean square error of approximation (RMSEA) = 0.08 (90% CI = 0.07-0.09)]. The Cronbach's alpha coefficient for the total items was 0.63 (0.82 for factor 1 and 0.72 for factor 2). The intraclass correlation coefficient (ICC) was 0.81 (95% CI: 0.62-0.91) for test-retest reliability testing after seven days. The total score and the negative component of the PSS-10 correlated significantly with the stress component of the DASS-21: (r = 0.61, P < 0.001) and (r = 0.56, P < 0.004), respectively. The Malay version of the PSS-10 demonstrated a satisfactory level of validity and reliability to assess stress perception. Therefore, this questionnaire is valid in assessing stress perception among nurses in Malaysia.

  7. Análise fatorial confirmatória das três versões da Perceived Stress Scale (PSS: um estudo populacional

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    André Faro

    2015-03-01

    Full Text Available Este estudo teve como objetivos realizar a análise fatorial confirmatória da Escala de Estresse Percebido (Perceived Stress Scale- PSS, nas versões traduzidas de 14, 10 e 4 itens; analisar sua validade concorrente com o Questionário de Saúde Geral (QSG-12; mapear o perfil do estresse em uma amostra representativa da população; e estabelecer parâmetros de avaliação do estresse por meio da normatização dos escores da população total. A amostragem foi de base populacional, em formato de conglomerado por setores censitários. Participaram 1.154 habitantes de uma capital do Nordeste brasileiro, sendo a maioria do sexo feminino (55,6%, com nível de escolaridade em ensino médio (51,7%, empregados (72,7% e não tabagistas (90,6%. As medianas de renda e idade ficaram em R$ 1.200,00 e 29 anos. Ao final, constatou-se que houve ajustes satisfatórios para as três versões da PSS apenas em seu modelo bifatorial e a escala com 10 itens se mostrou uma solução harmônica entre as versões completa e mais reduzida, considerando-se a relação entre a parcimônia na quantidade de itens e a robustez estatística deste instrumento. Ademais, a PSS ratificou sua validade concorrente com o QSG-12 e foi feita a normatização dos escores da PSS, estabelecendo-se parâmetros para comparação em futuros estudos.

  8. Adaptação cultural e validação para a língua portuguesa da Parental Stress Scale: Neonatal Intensive Care Unit (PSS:NICU Adaptación cultural y validación al idioma português del Parental Stress Scale: Neonatal Intensive Care Unit (PSS:NICU Cultural adaptation and validation for the portuguese language of the Parental Stress Scale: Neonatal Intensive Care Unit (PSS:NICU

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    Sandra Regina de Souza

    2012-01-01

    Full Text Available OBJETIVO: Traduzir, realizar a adaptação cultural e validar a escala Parental Stress Scale:Neonatal Intensive Care Unit (PSS:NICU para a língua portuguesa. MÉTODOS: Utilizou-se o método descritivo de validação de instrumentos de medida, baseado nas etapas propostas por Guillemin et al. A análise da confiabilidade foi realizada por meio dos testes e retestes e da consistência interna. Na validação clínica, participaram 163 pais de recém-nascidos internados em Unidade de Terapia Intensiva Neonatal (UTIN. RESULTADOS: Os coeficientes de correlação intraclasse ficaram em torno de 0,70 mostrando boa estabilidade entre as duas avaliações. A análise fatorial pelo método de componentes principais utilizou os mesmos critérios da escala original, com rotação Varimax, com grau de variância adequado de 57,9%. Os maiores níveis de estresse dos pais foram obtidos na subescala "alteração do papel de pais". CONCLUSÃO: A PSS:NICU na versão em português é uma ferramenta válida e confiável para avaliação do estresse de pais com filho internado na UTIN.OBJETIVO: Traducir, realizar la adaptación cultural y validar la escala Parental Stress Scale:Neonatal Intensive Care Unit (PSS:NICU al idioma portugués. MÉTODOS: Se utilizó el método descriptivo de validación de instrumentos de medida, basado en las etapas propuestas por Guillemin et al. El análisis de la confiabilidad fue realizado por medio de los tests y retests y de la consistencia interna. En la validación clínica, participaron 163 padres de recién nacidos internados en una Unidad de Cuidados Intensivos Neonatal (UCIN. RESULTADOS: Los coeficientes de correlación intraclase quedaron alrededor de 0,70 mostrando buena estabilidad entre las dos evaluaciones El análisis factorial por el método de componentes principales utilizó los mismos criterios de la escala original, con rotación Varimax, con grado de varianza adecuado de 57,9%. Los mayores niveles de estrés de

  9. Risk Management Challenges in Large-scale Energy PSS

    DEFF Research Database (Denmark)

    Tegeltija, Miroslava; Oehmen, Josef; Kozin, Igor

    2017-01-01

    Probabilistic risk management approaches have a long tradition in engineering. A large variety of tools and techniques based on the probabilistic view of risk is available and applied in PSS practice. However, uncertainties that arise due to lack of knowledge and information are still missing...... adequate representations. We focus on a large-scale energy company in Denmark as one case of current product/servicesystems risk management best practices. We analyze their risk management process and investigate the tools they use in order to support decision making processes within the company. First, we...... identify the following challenges in the current risk management practices that are in line with literature: (1) current methods are not appropriate for the situations dominated by weak knowledge and information; (2) quality of traditional models in such situations is open to debate; (3) quality of input...

  10. Risk Management Challenges in Large-scale Energy PSS

    DEFF Research Database (Denmark)

    Tegeltija, Miroslava; Oehmen, Josef; Kozin, Igor

    2017-01-01

    data and representation of the results to the decision makers play an important role. Second, we introduce a selection of alternative, so-called “post-probabilistic”, risk management methods developed across different scientific fields to cope with uncertainty due to lack of knowledge. Possibilities......Probabilistic risk management approaches have a long tradition in engineering. A large variety of tools and techniques based on the probabilistic view of risk is available and applied in PSS practice. However, uncertainties that arise due to lack of knowledge and information are still missing...... for overcoming industrial PSS risk management challenges are suggested through application of post-probabilistic methods. We conclude with the discussion on the importance for the field to consider their application....

  11. Perceived Stress Scale: Reliability and Validity Study in Greece

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    Eleni Andreou

    2011-08-01

    Full Text Available Objective: To translate the Perceived Stress Scale (versions PSS-4, -10 and -14 and to assess its psychometric properties in a sample of general Greek population. Methods: 941 individuals completed anonymously questionnaires comprising of PSS, the Depression Anxiety and Stress scale (DASS-21 version, and a list of stress-related symptoms. Psychometric properties of PSS were investigated by confirmatory factor analysis (construct validity, Cronbach’s alpha (reliability, and by investigating relations with the DASS-21 scores and the number of symptoms, across individuals’ characteristics. The two-factor structure of PSS-10 and PSS-14 was confirmed in our analysis. We found satisfactory Cronbach’s alpha values (0.82 for the full scale for PSS-14 and PSS-10 and marginal satisfactory values for PSS-4 (0.69. PSS score exhibited high correlation coefficients with DASS-21 subscales scores, meaning stress (r = 0.64, depression (r = 0.61, and anxiety (r = 0.54. Women reported significantly more stress compared to men and divorced or widows compared to married or singled only. A strong significant (p < 0.001 positive correlation between the stress score and the number of self-reported symptoms was also noted. Conclusions: The Greek versions of the PSS-14 and PSS-10 exhibited satisfactory psychometric properties and their use for research and health care practice is warranted.

  12. Perceived Stress Scale: reliability and validity study in Greece.

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    Andreou, Eleni; Alexopoulos, Evangelos C; Lionis, Christos; Varvogli, Liza; Gnardellis, Charalambos; Chrousos, George P; Darviri, Christina

    2011-08-01

    To translate the Perceived Stress Scale (versions PSS-4, -10 and -14) and to assess its psychometric properties in a sample of general Greek population. 941 individuals completed anonymously questionnaires comprising of PSS, the Depression Anxiety and Stress scale (DASS-21 version), and a list of stress-related symptoms. Psychometric properties of PSS were investigated by confirmatory factor analysis (construct validity), Cronbach's alpha (reliability), and by investigating relations with the DASS-21 scores and the number of symptoms, across individuals' characteristics. The two-factor structure of PSS-10 and PSS-14 was confirmed in our analysis. We found satisfactory Cronbach's alpha values (0.82 for the full scale) for PSS-14 and PSS-10 and marginal satisfactory values for PSS-4 (0.69). PSS score exhibited high correlation coefficients with DASS-21 subscales scores, meaning stress (r = 0.64), depression (r = 0.61), and anxiety (r = 0.54). Women reported significantly more stress compared to men and divorced or widows compared to married or singled only. A strong significant (p < 0.001) positive correlation between the stress score and the number of self-reported symptoms was also noted. The Greek versions of the PSS-14 and PSS-10 exhibited satisfactory psychometric properties and their use for research and health care practice is warranted.

  13. The construct validity of the Perceived Stress Scale

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    Germund Nielsen, Marie; Ørnbøl, Eva; Vestergaard, Mogens

    2016-01-01

    Objective: Stress impacts the quality of life and is associated with increased risk of mental and physical disorders. The Perceived Stress Scale (PSS) is widely used for measuring psychological distress. Although the instrument was originally defined as a single construct, several studies based...... of 32,374 citizens who completed the PSS-10 as part of the Danish National Health Survey in 2010. We investigated the construct validity of the PSS-10 by CFA. We examined the scalability by investigating the fit of the data distribution in a unidimensional Rasch model and performing modification...... of response categories, persons and items. The scale dimensionality was additionally assessed by Mokken and Rasch analysis.  Results: The PSS-10 did not fit the Rasch model. Item four indicated the largest misfit, and items four and seven displayed disordered thresholds. Unidimensionality could...

  14. Validation of Bengali perceived stress scale among LGBT population.

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    Mozumder, Muhammad Kamruzzaman

    2017-08-29

    Lesbian, gay, bisexual and transgender (LGBT) population encounter more stressful life circumstances compared to general population. Perceived Stress Scale (PSS) can be a useful tool for measuring their stress. However, psychometric properties of PSS have never been tested on LGBT population. This cross sectional study employed a two-stage sampling strategy to collect data from 296 LGBT participants from six divisional districts of Bangladesh. Exploratory (EFA) and confirmatory factor analysis (CFA) were carried out on PSS 10 along with analysis of reliability and validity. EFA revealed a two-factor structure of PSS for LGBT population explaining 43.55% - 51.45% of total variance. This measurement model was supported by multiple fit indices during CFA. Acceptable Cronbach's alpha indicated internal consistency reliability and high correlations with Self Reporting Questionnaire 20 demonstrated construct validity of PSS 10 for LGBT population. This study provided evidence of satisfactory psychometric properties of Bengali PSS 10 in terms of factor structure, internal consistency and validity among LGBT population.

  15. Design of optimal input–output scaling factors based fuzzy PSS using bat algorithm

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    D.K. Sambariya

    2016-06-01

    Full Text Available In this article, a fuzzy logic based power system stabilizer (FPSS is designed by tuning its input–output scaling factors. Two input signals to FPSS are considered as change of speed and change in power, and the output signal is considered as a correcting voltage signal. The normalizing factors of these signals are considered as the optimization problem with minimization of integral of square error in single-machine and multi-machine power systems. These factors are optimally determined with bat algorithm (BA and considered as scaling factors of FPSS. The performance of power system with such a designed BA based FPSS (BA-FPSS is compared to that of response with FPSS, Harmony Search Algorithm based FPSS (HSA-FPSS and Particle Swarm Optimization based FPSS (PSO-FPSS. The systems considered are single-machine connected to infinite-bus, two-area 4-machine 10-bus and IEEE New England 10-machine 39-bus power systems for evaluating the performance of BA-FPSS. The comparison is carried out in terms of the integral of time-weighted absolute error (ITAE, integral of absolute error (IAE and integral of square error (ISE of speed response for systems with FPSS, HSA-FPSS and BA-FPSS. The superior performance of systems with BA-FPSS is established considering eight plant conditions of each system, which represents the wide range of operating conditions.

  16. High-stress study of bioinspired multifunctional PEDOT:PSS/nanoclay nanocomposites using AFM, SEM and numerical simulation

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    Alfredo J. Diaz

    2017-10-01

    Full Text Available Bioinspired design has been central in the development of hierarchical nanocomposites. Particularly, the nacre-mimetic brick-and-mortar structure has shown excellent mechanical properties, as well as gas-barrier properties and optical transparency. Along with these intrinsic properties, the layered structure has also been utilized in sensing devices. Here we extend the multifunctionality of nacre-mimetics by designing an optically transparent and electron conductive coating based on PEDOT:PSS and nanoclays Laponite RD and Cloisite Na+. We carry out extensive characterization of the nanocomposite using transmittance spectra (transparency, conductive atomic force microscopy (conductivity, contact-resonance force microscopy (mechanical properties, and SEM combined with a variety of stress-strain AFM experiments and AFM numerical simulations (internal structure. We further study the nanoclay’s response to the application of pressure with multifrequency AFM and conductive AFM, whereby increases and decreases in conductivity can occur for the Laponite RD composites. We offer a possible mechanism to explain the changes in conductivity by modeling the coating as a 1-dimensional multibarrier potential for electron transport, and show that conductivity can change when the separation between the barriers changes under the application of pressure, and that the direction of the change depends on the energy of the electrons. We did not observe changes in conductivity under the application of pressure with AFM for the Cloisite Na+ nanocomposite, which has a large platelet size compared with the AFM probe diameter. No pressure-induced changes in conductivity were observed in the clay-free polymer either.

  17. Psychometric evaluation of Turkish version of the Perceived Stress Scale with Turkish college students.

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    Kaya, Cahit; Tansey, Timothy N; Melekoglu, Macid; Cakiroglu, Orhan; Chan, Fong

    2017-12-20

    The Turkish version of the Perceived Stress Scale (T-PSS-10) measures the extent to which situations in one's life are appraised as stressful. The purpose of this study was to evaluate the measurement structure of T-PSS-10. Two-hundred and thirty-five Turkish university students (93 men and 142 women) completed the T-PSS-10, the Patient Health Questionnaire-9 (PHQ-9), the General Anxiety Disorder 7-Item Scale (GAD-7), and the Inventory of Common Problems (ICP). Confirmatory factor analysis results indicated that a one-factor model did not fit the data, whereas a two-factor correlated model (stress related self-efficacy beliefs, stress related feelings of helplessness) provided a better fit between the model and the data. Significant moderate correlations were found for the stress-related self-efficacy beliefs and stress-related feelings of helplessness factors with depression, anxiety, academic difficulty, relationship problems and health problems. The internal consistency reliability coefficients for the stress-related self-efficacy beliefs and stress-related feelings of helplessness factors were 0.68 and 0.85, respectively. This study provided support for the reliability and validity of T-PSS-10 suggesting that it can be used as a screening instrument by health professionals working with Turkish college students.

  18. PSS Case Book

    DEFF Research Database (Denmark)

    Neugebauer, Line Maria; Mougaard, Krestine; Andersen, Jakob Bejbro

    The transformation process towards a PSS-oriented company is describes, through the presentation of the best practice cases. Each case describes motivations, challenges, business models and PSS offerings....

  19. Psychometric properties of the Chinese version of the Perceived Stress Scale in policewomen.

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    Zhen Wang

    Full Text Available BACKGROUND: The 10-item Perceived Stress Scale (PSS-10 is one of most widely used instruments to measure a global level of perceived stress in a range of clinical and research settings. This study was conducted to examine the psychometric properties of the Simplified Chinese version of the PSS-10 in policewomen. METHODOLOGY: A total of 240 policewomen were recruited in this study. The Simplified Chinese versions of the PSS-10, the Beck Depression Inventory Revised (BDI-II, and the Beck Anxiety Inventory (BAI were administered to all participants, and 36 of the participants were re-tested two weeks after the initial testing. PRINCIPAL FINDINGS: The overall Cronbach's alpha was 0.86, and the test-retest reliability coefficient was 0.68. Exploratory Factor Analysis (EFA yielded 2 factors with eigenvalues of 4.76 and 1.48, accounting for 62.41% of variance. Factor 1 consisted of 6 items representing "negative feelings"; whereas Factor 2 consisted of 4 items representing "positive feelings". The item loadings ranged from 0.72 to 0.83. The Confirmatory factor analysis (CFA indicated a very good fit of this two-factor model to this sample. The PSS-10 significantly correlated with both BDI-II and BAI, indicating an acceptable concurrent validity. CONCLUSIONS: The Simplified Chinese version of the PSS-10 demonstrated adequate psychometric properties for evaluating stress levels. The results support its use among the Chinese population.

  20. Pulse Synchronization System (PSS)

    International Nuclear Information System (INIS)

    1977-06-01

    This document is intended to serve as an operations manual, as well as a documentation of the backup analyses pertinent to the design as delivered. A history of earlier unsuccessful versions of the Pulse Synchronization System (PSS) is not included. The function of the PSS is to synchronize the time of arrival at the fusion target of laser pulses that are propagated through the 20 amplifier chains of the SHIVA laser. The positional accuracy requirement is +-1.5 mm (+-5 psec), and is obtained by the PSS with a wide margin factor

  1. Parental Stress Scale: Validation study with a Portuguese population of parents of children from 3 to 10 years old.

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    Algarvio, Susana; Leal, Isabel; Maroco, João

    2018-01-01

    The aim of this study was to validate the Parental Stress Scale (PSS) for Portuguese parents and to further investigate the scale's criterion-related validity. A two-stage stratified sample of the Portuguese population of parents, with children attending public preschools and primary schools, was obtained, totalizing 3842 parents of children between 3 and 10 years old. Parents completed a Parental Concerns Scale and the Portuguese version of the PSS. Results support the four-factor structure of the Portuguese version of the PSS. Higher levels of parental stress were reported by parents of boys, with lower educational levels; older, divorced or single parents; unemployed mothers; and with a higher number of children. Parental concerns and parental stress' comparative study reported very low correlations between the two constructs. This study supported evidence for the PSS' validity with a stratified sample of Portuguese parents of children between 3 and 10 years old. Moreover, our findings reported the scale's divergent validity with a Parental Concerns Scale. These results point to the importance of assessing both dimensions in family practice.

  2. Evaluation of psychometric properties of the malay version perceived stress scale in two occupational settings in malaysia.

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    Al-Dubai, Sar; Ganasegeran, K; Barua, A; Rizal, Am; Rampal, Kg

    2014-07-01

    The 10-item version of Perceived Stress Scale (PSS-10) is a widely used tool to measure stress. The Malay version of the PSS-10 has been validated among Malaysian Medical Students. However, studies have not been conducted to assess its validity in occupational settings. The aim of this study is to assess the psychometric properties of the Malay version of the PSS-10 in two occupational setting in Malaysia. This study was conducted among 191 medical residents and 513 railway workers. An exploratory factor analysis was performed using the principal component method with varimax rotation. Correlation analyses, Kaiser-Meyer-Olkin, Bartlett's test of Sphericity and Cronbach's alpha were obtained. Statistical analysis was carried out using statistical package for the social sciences version 16 (SPSS, Chicago, IL, USA) software. Analysis yielded two factor structure of the Malay version of PSS-10 in both occupational groups. The two factors accounted for 59.2% and 64.8% of the variance in the medical residents and the railway workers respectively. Factor loadings were greater than 0.59 in both occupational groups. Cronbach's alpha co-efficient was 0.70 for medical residents and 0.71 for railway workers. The Malay version of PSS-10 had adequate psychometric properties and can be used to measure stress among occupational settings in Malaysia.

  3. Review of the Psychometric Evidence of the Perceived Stress Scale

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    Eun-Hyun Lee, RN, PhD

    2012-12-01

    Conclusion: Overall, the PSS is an easy-to-use questionnaire with established acceptable psychometric properties. However, future studies should evaluate these psychometric properties in greater depth, and validate the scale using diverse populations.

  4. The Thai version of the PSS-10: An Investigation of its psychometric properties.

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    Wongpakaran, Nahathai; Wongpakaran, Tinakon

    2010-06-12

    Among the stress instruments that measure the degree to which life events are perceived as stressful, the Perceived Stress Scale (PSS) is widely used. The goal of this study was to examine the psychometric properties of a Thai version of the PSS-10 (T-PSS-10) with a clinical and non-clinical sample. Internal consistency, test-retest reliability, concurrent validity, and the factorial structure of the scale were tested. A total sample of 479 adult participants was recruited for the study: 368 medical students and 111 patients from two hospitals in Northern Thailand. The T-PSS-10 was used along with the Thai version of State Trait Anxiety Inventory (STAI), the Thai Version of the Rosenberg Self-Esteem Scale (RSES), and the Thai Depression Inventory (TDI). Exploratory Factor Analysis (EFA) yielded 2 factors with eigenvalues of 5.05 and 1.60, accounting for 66 percent of variance. Factor 1 consisted of 6 items representing "stress"; whereas Factor 2 consisted of 4 items representing "control". The item loadings ranged from 0.547 to 0.881. Investigation of the fit indices associated with Maximum Likelihood (ML) estimation revealed that the two-factor solution was adequate [chi2 = 35.035 (df = 26, N = 368, p reliability. The Thai version of the PSS-10 demonstrated excellent goodness-of-fit for the two factor solution model, as well as good reliability and validity for estimating the level of stress perception with a Thai population. Limitations of the study are discussed.

  5. The Thai version of the PSS-10: An Investigation of its psychometric properties

    Directory of Open Access Journals (Sweden)

    Wongpakaran Tinakon

    2010-06-01

    Full Text Available Abstract Background Among the stress instruments that measure the degree to which life events are perceived as stressful, the Perceived Stress Scale (PSS is widely used. The goal of this study was to examine the psychometric properties of a Thai version of the PSS-10 (T-PSS-10 with a clinical and non-clinical sample. Internal consistency, test-retest reliability, concurrent validity, and the factorial structure of the scale were tested. Methods A total sample of 479 adult participants was recruited for the study: 368 medical students and 111 patients from two hospitals in Northern Thailand. The T-PSS-10 was used along with the Thai version of State Trait Anxiety Inventory (STAI, the Thai Version of the Rosenberg Self-Esteem Scale (RSES, and the Thai Depression Inventory (TDI. Results Exploratory Factor Analysis (EFA yielded 2 factors with eigenvalues of 5.05 and 1.60, accounting for 66 percent of variance. Factor 1 consisted of 6 items representing "stress"; whereas Factor 2 consisted of 4 items representing "control". The item loadings ranged from 0.547 to 0.881. Investigation of the fit indices associated with Maximum Likelihood (ML estimation revealed that the two-factor solution was adequate [χ2 = 35.035 (df = 26, N = 368, p r = 0.60, p r = 0.55, p r = -0.46, p Conclusions The Thai version of the PSS-10 demonstrated excellent goodness-of-fit for the two factor solution model, as well as good reliability and validity for estimating the level of stress perception with a Thai population. Limitations of the study are discussed.

  6. At-risk and intervention thresholds of occupational stress using a visual analogue scale

    Science.gov (United States)

    Pereira, Bruno; Moustafa, Farès; Naughton, Geraldine; Lesage, François-Xavier; Lambert, Céline

    2017-01-01

    Background The visual analogue scale (VAS) is widely used in clinical practice by occupational physicians to assess perceived stress in workers. However, a single cut-off (black-or-white decision) inadequately discriminates between workers with and without stress. We explored an innovative statistical approach to distinguish an at-risk population among stressed workers, and to establish a threshold over which an action is urgently required, via the use of two cut-offs. Methods Participants were recruited during annual work medical examinations by a random sample of workers from five occupational health centres. We previously proposed a single cut-off of VAS stress in comparison with the Perceived Stress Scale (PSS14). Similar methodology was used in the current study, along with a gray zone approach. The lower limit of the gray zone supports sensitivity (“at-risk” threshold; interpreted as requiring closer surveillance) and the upper limit supports specificity (i.e. “intervention” threshold–emergency action required). Results We included 500 workers (49.6% males), aged 40±11 years, with a PSS14 score of 3.8±1.4 and a VAS score of 4.0±2.4. Using a receiver operating characteristic curve and the PSS cut-off score of 7.2, the optimal VAS threshold was 6.8 (sensitivity = 0.89, specificity = 0.87). The lower and upper thresholds of the gray zone were 5 and 8.2, respectively. Conclusions We identified two clinically relevant cut-offs on the VAS of stress: a first cut-off of 5.0 for an at-risk population, and a second cut-off of 8.2 over which an action is urgently required. Future investigations into the relationships between this upper threshold and deleterious events are required. PMID:28586383

  7. Cross-cultural adaptation and validation of the Danish consensus version of the 10-item Perceived Stress Scale

    DEFF Research Database (Denmark)

    Eskildsen, Anita; Dalgaard, Vita Ligaya; Nielsen, Kent Jacob

    2015-01-01

    with work-related stress complaints. METHODS: A consensus-building process was performed involving the authors of the three previous Danish translations and the consensus version was back-translated into English and pilot-tested. Psychometric properties of the final version were examined in a sample of 64...... patients with work-related stress complaints. RESULTS: The face validity, reliability, and internal consistency of the Danish consensus version of the PSS-10 were satisfactory, and convergent construct validity was confirmed. Receiver operating characteristic (ROC) curves of the change scores showed......OBJECTIVES: The aims of the present study were to (i) cross-culturally adapt a Danish consensus version of the 10-item Perceived Stress Scale (PSS-10) and (ii) evaluate its psychometric properties in terms of agreement, reliability, validity, responsiveness, and interpretability among patients...

  8. PSS: beyond the implementation gap

    NARCIS (Netherlands)

    Geertman, S.C.M.

    2017-01-01

    In the last couple of decades, a large number of papers on planning support systems (PSS) have been published in national and international, scientific and professional journals. What is remarkable about PSS is that for quite some time their history has been dominated by an implementation gap, that

  9. Deciding on PSS: A Framework for PSS Strategies

    DEFF Research Database (Denmark)

    Neugebauer, Line Maria; Mougaard, Krestine; Andersen, Jakob Axel Bejbro

    2013-01-01

    Product/Service-Systems (PSS) are a strategic approach wherein the value proposition covers the performance of a system throughout the whole life cycle. Many industrial companies are challenged on many levels in the transition process towards a PSS oriented approach. Much of the literature has...... until now focused on PSS from a design object perspective, and less focus has been on how the business model of the company must be designed simultaneously with the offering, covering topics as organisational restructuring, value chain collaboration plus a change management focus. This paper presents...

  10. Validity and reliability of the Cohen 10-item Perceived Stress Scale in patients with chronic headache: Persian version.

    Science.gov (United States)

    Khalili, Robabe; Sirati Nir, Masoud; Ebadi, Abbas; Tavallai, Abbas; Habibi, Mehdi

    2017-04-01

    The Cohen Perceived Stress Scale is being used widely in various countries. The present study evaluated the validity and reliability of the Cohen 10-item Perceived Stress Scale (PSS-10) in assessing tension headache, migraine, and stress-related diseases in Iran. This study is a methodological and cross-sectional descriptive investigation of 100 patients with chronic headache admitted to the pain clinic of Baqiyatallah Educational and Therapeutic Center. Convenience sampling was used for subject selection. PSS psychometric properties were evaluated in two stages. First, the standard scale was translated. Then, the face validity, content, and construct of the translated version were determined. The average age of participants was 38 years with a standard deviation (SD) of 13.2. As for stress levels, 12% were within the normal range, 36% had an intermediate level, and 52% had a high level of stress. The face validity and scale content were remarkable, and the KMO coefficient was 0.82. Bartlett's test yielded 0.327 which was statistically significant (pstress and chronic headache. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Assessing product service systems (PSS)

    DEFF Research Database (Denmark)

    Hsuan, Juliana; McAloone, Tim C.; Neugebauer, Line

    We apply a management tool to classify different integrated PSS within the context of Danish maritime industry. We investigate how a firm should organize its operations to manage the transition from being a manufacturing to a servitizing company, and to provide a guideline for strategic positioni...... and planning of the balance between product sales and service activities....

  12. Decohesion Kinetics of PEDOT:PSS Conducting Polymer Films

    KAUST Repository

    Dupont, Stephanie R.; Novoa, Fernando; Voroshazi, Eszter; Dauskardt, Reinhold H.

    2013-01-01

    The highly conductive polymer PEDOT:PSS is a widely used hole transport layer and transparent electrode in organic electronic devices. To date, the mechanical and fracture properties of this conductive polymer layer are not well understood. Notably, the decohesion rate of the PEDOT:PSS layer and its sensitivity to moist environments has not been reported, which is central in determining the lifetimes of organic electronic devices. Here, it is demonstrated that the decohesion rate is highly sensitive to the ambient moisture content, temperature, and mechanical stress. The kinetic mechanisms are elucidated using atomistic bond rupture models and the decohesion process is shown to be facilitated by a chemical reaction between water molecules from the environment and strained hydrogen bonds. Hydrogen bonds are the predominant bonding mechanism between individual PEDOT:PSS grains within the layer and cause a significant loss in cohesion when they are broken. Understanding the decohesion kinetics and mechanisms in these films is essential for the mechanical integrity of devices containing PEDOT:PSS layers and yields general guidelines for the design of more reliable organic electronic devices. Decohesion rate in PEDOT:PSS conducting films is studied under varied environmental conditions. The moisture content in the environment is the most important factor accelerating the decohesion in the PEDOT:PSS layer, which is detrimental for device reliability. The findings on the decohesion rate and mechanisms, elucidated by atomic kinetic models, are essential for the design of more reliable organic electronic devices containting PEDOT:PSS layers. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Decohesion Kinetics of PEDOT:PSS Conducting Polymer Films

    KAUST Repository

    Dupont, Stephanie R.

    2013-10-17

    The highly conductive polymer PEDOT:PSS is a widely used hole transport layer and transparent electrode in organic electronic devices. To date, the mechanical and fracture properties of this conductive polymer layer are not well understood. Notably, the decohesion rate of the PEDOT:PSS layer and its sensitivity to moist environments has not been reported, which is central in determining the lifetimes of organic electronic devices. Here, it is demonstrated that the decohesion rate is highly sensitive to the ambient moisture content, temperature, and mechanical stress. The kinetic mechanisms are elucidated using atomistic bond rupture models and the decohesion process is shown to be facilitated by a chemical reaction between water molecules from the environment and strained hydrogen bonds. Hydrogen bonds are the predominant bonding mechanism between individual PEDOT:PSS grains within the layer and cause a significant loss in cohesion when they are broken. Understanding the decohesion kinetics and mechanisms in these films is essential for the mechanical integrity of devices containing PEDOT:PSS layers and yields general guidelines for the design of more reliable organic electronic devices. Decohesion rate in PEDOT:PSS conducting films is studied under varied environmental conditions. The moisture content in the environment is the most important factor accelerating the decohesion in the PEDOT:PSS layer, which is detrimental for device reliability. The findings on the decohesion rate and mechanisms, elucidated by atomic kinetic models, are essential for the design of more reliable organic electronic devices containting PEDOT:PSS layers. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Thin film free-standing PEDOT:PSS/SU8 bilayer microactuators

    International Nuclear Information System (INIS)

    Taccola, S; Greco, F; Mazzolai, B; Mattoli, V; Jager, E W H

    2013-01-01

    Several smart active materials have been proposed and tested for the development of microactuators. Among these, conjugated polymers are of great interest because miniaturization improves their electrochemical properties, such as increasing the speed and stress output of microactuators, with respect to large-scale actuators. Recently we developed a novel fabrication process to obtain robust free-standing conductive ultra-thin films made of the conjugated polymer poly(3, 4-ethylenedioxythiophene) doped with the polyanion poly(styrenesulfonate) (PEDOT:PSS). These conductive free-standing nanofilms, with thicknesses ranging between a few tens to several hundreds of nm, allow the realisation of new all polymer microactuators using facile microfabrication methods. Here, we report a novel processing method for manufacturing all polymer electrochemical microactuators. We fabricated and patterned free-standing PEDOT:PSS/SU8 bilayer microactuators in the form of microfingers of a variety of lengths using adapted microfabrication procedures. By imposing electrochemical oxidation/reduction cycles on the PEDOT:PSS we were able to demonstrate reversible actuation of the microactuators resulting in bending of the microfingers. A number of possible applications can be envisaged for these small, soft actuators, such as microrobotics and cell manipulation. (technical note)

  15. Psychometric Validation of Stress and Compliance Scale for ...

    African Journals Online (AJOL)

    Keywords: Diabetes mellitus, Malaysia stress scale, Stress and compliance scale for diabetes, Stress, ... and 'Rate your life on current life satisfaction scale!' People rated how often they ..... Handbook of depression in children and adolescents.

  16. Development of the perceived stress scale for people living with HIV/AIDS in China.

    Science.gov (United States)

    Su, Xiaoyou; Lau, Joseph T F; Mak, Winnie W S; Chen, Lin; Feng, Tiejian; Chen, Xi; Liu, Chuliang; Liu, Jun; Liu, De; Cheng, Jinquan

    2008-12-01

    Stress among people living with HIV/AIDS (PLWHA) is associated with psychological morbidity. There are only a few stress scales specially developed for PLWHA and none of them is in Chinese. This study develops and validates a new Chinese Perceived Stress Scale among PLWHA (PSSHIV) in Shenzhen of Guangdong Province and Hengyang of Hunan Province in China during September 2006 through July 2007. In-depth interviews were administered to 58 PLWHA (33 males, mean age, 32) to generate the items, while 215 other PLWHA were interviewed in another survey to validate the instrument (136 males, mean age, 33). Exploratory factor analysis yielded 8 factors (percent variance explained, 71.47%), namely: social/psychological problems, sexual relationship, functional problems, social acceptance/rejection issues, work-related issues, family/offspring issues, accessibility to treatment, and treatment outcomes. The Cronbach alpha values ranged from 0.76 to 0.94 for the overall scale and the 8 subscales. The scores of the overall scale, the social/psychological problems, and functional problems subscales of the PSSHIV were significantly correlated with the Perceived Stress Scale (PSS), Depression, Anxiety and Stress Scale (DASS), and all domains of the Medical Outcomes Study HIV Health Survey (MOS-HIV) (correlation coefficient = 0.50 to 0.71 for positive correlations, and -0.73 to -0.21 for negative correlations, p DASS, and MOS-HIV (correlation coefficient = 0.16 to 0.39 for positive correlation, -0.58 to -0.15 for negative correlation, p < 0.05). This new instrument collected information from the PLWHA from qualitative interviews and the items are specific to the HIV/AIDS context. PSSHIV can be used for assessing the level of stress faced by PLWHA in China.

  17. Layered composites of PEDOT/PSS/nanoparticles and PEDOT/PSS/phthalocyanines as electron mediators for sensors and biosensors

    Directory of Open Access Journals (Sweden)

    Celia García-Hernández

    2016-12-01

    Full Text Available The sensing properties of electrodes chemically modified with PEDOT/PSS towards catechol and hydroquinone sensing have been successfully improved by combining layers of PEDOT/PSS with layers of a secondary electrocatalytic material such as gold nanoparticles (PEDOT/PSS/AuNPs, copper phthalocyanine (PEDOT/PSS/CuPc or lutetium bisphthalocyanine (PEDOT/PSS/LuPc2. Layered composites exhibit synergistic effects that strongly enhance the electrocatalytic activity as indicated by the increase in intensity and the shift of the redox peaks to lower potentials. A remarkable improvement has been achieved using PEDOT/PSS/LuPc2, which exhibits excellent electrocatalytic activity towards the oxidation of catechol. The kinetic studies demonstrated diffusion-controlled processes at the electrode surfaces. The kinetic parameters such as Tafel slopes and charge transfer coefficient (α confirm the improved electrocatalytic activity of the layered electron mediators. The peak currents increased linearly with concentration of catechol and hydroquinone over the range of 1.5 × 10−4 to 4.0 × 10−6 mol·L−1 with a limit of detection on the scale of μmol·L−1. The layered composite hybrid systems were also found to be excellent electron mediators in biosensors containing tyrosinase and laccase, and they combine the recognition and biocatalytic properties of biomolecules with the unique catalytic features of composite materials. The observed increase in the intensity of the responses allowed detection limits of 1 × 10−7 mol·L−1 to be attained.

  18. CNNH_PSS: protein 8-class secondary structure prediction by convolutional neural network with highway.

    Science.gov (United States)

    Zhou, Jiyun; Wang, Hongpeng; Zhao, Zhishan; Xu, Ruifeng; Lu, Qin

    2018-05-08

    Protein secondary structure is the three dimensional form of local segments of proteins and its prediction is an important problem in protein tertiary structure prediction. Developing computational approaches for protein secondary structure prediction is becoming increasingly urgent. We present a novel deep learning based model, referred to as CNNH_PSS, by using multi-scale CNN with highway. In CNNH_PSS, any two neighbor convolutional layers have a highway to deliver information from current layer to the output of the next one to keep local contexts. As lower layers extract local context while higher layers extract long-range interdependencies, the highways between neighbor layers allow CNNH_PSS to have ability to extract both local contexts and long-range interdependencies. We evaluate CNNH_PSS on two commonly used datasets: CB6133 and CB513. CNNH_PSS outperforms the multi-scale CNN without highway by at least 0.010 Q8 accuracy and also performs better than CNF, DeepCNF and SSpro8, which cannot extract long-range interdependencies, by at least 0.020 Q8 accuracy, demonstrating that both local contexts and long-range interdependencies are indeed useful for prediction. Furthermore, CNNH_PSS also performs better than GSM and DCRNN which need extra complex model to extract long-range interdependencies. It demonstrates that CNNH_PSS not only cost less computer resource, but also achieves better predicting performance. CNNH_PSS have ability to extracts both local contexts and long-range interdependencies by combing multi-scale CNN and highway network. The evaluations on common datasets and comparisons with state-of-the-art methods indicate that CNNH_PSS is an useful and efficient tool for protein secondary structure prediction.

  19. AN OBSERVATIONAL CLINICAL STUDY OF ASSESSING THE UTILITY OF PSS (POISON SEVERITY SCORE AND GCS (GLASGOW COMA SCALE SCORING SYSTEMS IN PREDICTING SEVERITY AND CLINICAL OUTCOMES IN OP POISONING

    Directory of Open Access Journals (Sweden)

    S. Chandrasekhar

    2017-05-01

    Full Text Available BACKGROUND Organophosphorus compound poisoning is the most common poisonings in India because of easy availability often requiring ICU care and ventilator support. Clinical research has indicated that respiratory failure is the most important cause of death due to organophosphorus poisoning. It results in respiratory muscle weakness, pulmonary oedema, respiratory depression, increased secretions and bronchospasm. These complications and death can be prevented with timely institution of ventilator support. MATERIALS AND METHODS Hundred consecutive patients admitted with a history of organophosphorus poisoning at Kurnool Medical College, Kurnool, were taken for study after considering the inclusion and exclusion criteria. Detailed history, confirmation of poisoning, examination and other than routine investigations, serum pseudocholinesterase and arterial blood gas analysis was done. The severity and clinical outcomes in OP poisoning is graded by PSS (poison severity score and GCS (Glasgow coma scale scoring systems. RESULTS This study was conducted in 100 patients with male preponderance. Majority of poisoning occurred in 21-30 age group (n=5. Most common compound consumed in our study was methyl parathion and least common was phosphoran. Slightly more than half of the patients consumed less than 50 mL of poison. 21 patients consumed between 50 to 100 mL. Distribution of poison severity score of patients studied showed 45 cases of grade 1 poisoning. 26 cases of grade 2 poisoning, 23 cases of grade 3 poisoning and 6 cases of grade 4 poisoning (death within first 24 hours. Distribution of GCS score of patients studied GCS scores were <10 in 25 patients at admission and 24 patients after 24 hours. GCS scores were ≥10 in 75 patients at admission and 76 patients after 24 hours. Poison severity score is not prognostic, but merely defines severity of OP poisoning at a given time. CONCLUSION Both Glasgow coma scale and poison severity scoring systems

  20. Improved stability of OLEDs with mild oxygen plasma treated PEDOT:PSS

    International Nuclear Information System (INIS)

    Zhou Yunfei; Yuan Yongbo; Cao Lingfang; Zhang Jie; Pang Hongqi; Lian Jiarong; Zhou Xiang

    2007-01-01

    We demonstrate improved stability of OLEDs with mild oxygen plasma-treated poly (3,4-ethylenedioxythiophene) doped with poly (styrenesulfonate) (PEDOT:PSS) as anode buffer layer. The devices with treated PEDOT:PSS layer exhibited dramatically enhanced lifetime by a factor of 9 compared to the control devices. We investigated the substantial changes in surface morphology of PEDOT:PSS layer after the mild oxygen plasma treatment by scanning electron microscopy and atomic force microscopy. We found that the appropriate treatment can form uniformly distributed nano scaled hillocks/islands on the surface of PEDOT:PSS layer, which possibly result in improved contact to hole transport layer and thus enhanced lifetime of the devices

  1. Psychosocial stress as a risk factor for sepsis: a population-based cohort study.

    Science.gov (United States)

    Ojard, Connor; Donnelly, John P; Safford, Monika M; Griffin, Russell; Wang, Henry E

    2015-01-01

    To characterize the relationship between stress and future risk of sepsis. We also evaluated the role of depression in this relationship. We used population-based data on 30,183 participants in the Reasons for Geographic and Racial Differences in Stroke cohort, characterizing stress using the Perceived Stress Scale (PSS) and depressive symptoms using the Center for Epidemiologic Studies Depression Scale (CES-D). We identified incident sepsis events as hospitalizations for a serious infection with the presence of at least two systemic inflammatory response syndrome criteria. We assessed associations between PSS and incidence of sepsis for 1 and 10 years of follow-up, adjusting for demographics and chronic medical conditions and assessing the role of health behaviors and CES-D in these relationships. In 2003 to 2012, 1500 participants experienced an episode of sepsis. Mean PSS and CES-D scores were 3.2 (2.9) and 1.2 (2.1). PSS was associated with increased 1-year adjusted incidence of sepsis (hazard ratio [HR] = 1.21 per PSS standard deviation, 95% confidence interval = 1.06-1.38); multivariable adjustment for health behaviors and CES-D did not change this association (1.20, 1.03-1.39). PSS was also associated with increased 10-year adjusted incidence of sepsis (HR = 1.07 per PSS standard deviation; 95% confidence interval = 1.02-1.13). Multivariable adjustment showed that health behaviors did not affect this long-term association, whereas the addition of CES-D reduced the association between PSS and sepsis during 10-year follow-up (HR = 1.04, 0.98-1.11). Increased stress was associated with higher 1-year adjusted incidence of sepsis, even after accounting for depressive symptoms. The association between stress and 10-year adjusted incidence of sepsis was also significant, but this association was reduced when adjusting for depressive symptoms. Reduction of stress may limit short-term sepsis risk.

  2. Development of a screening measure of stress for parents of children hospitalised in a Paediatric Intensive Care Unit.

    Science.gov (United States)

    Rodríguez-Rey, Rocío; Alonso-Tapia, Jesús

    2016-08-01

    Having a child admitted to intensive care is a highly stressful experience for parents; however there is a lack of screening instruments of parental stress in that context, which would be useful for both, research and clinical purposes. (1) To validate a brief measure of parental stress based on the Parental Stressor Scale: Paediatric Intensive Care Unit (PSS:PICU), (2) to study which environmental factors of the PICU are more stressful in a sample of Spanish parents, and (3) to study which variables are related to higher levels of stress among this group. 196 Spanish parents completed the Abbreviated PSS: PICU (A-PSS:PICU) and a general stress scale (the Perceived Stress Scale) upon their child's discharge to test the convergent validity of the tool. Three months later, they were assessed anxiety and depression using the Hospital Anxiety and Depression Scale, and posttraumatic stress with the Davidson Trauma Scale in order to test the predictive validity of the A-PSS:PICU. Two factors emerged from Confirmatory Factor Analyses, (1) stress due to child's condition and (2) stress related to PICU's staff. The A-PSS:PICU showed adequate reliability and convergent and predictive validity. The most stressful aspects were the behaviours and emotional responses of their child and the loss of their parental role. Age, gender, child's condition, length of admission, spiritual beliefs, and mechanical ventilation were associated to parental stress scores. The A-PSS:PICU is a reliable and valid measure. Parental stress should be screened during a child's PICU admission to identify parents at risk of post-discharge distress. Copyright © 2016 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.

  3. Length scale of secondary stresses in fracture and fatigue

    International Nuclear Information System (INIS)

    Dong, P.

    2008-01-01

    In an attempt to provide a consistent framework for the analysis and treatment of secondary stresses associated with welding and thermal loading in the context of fracture mechanics, this paper starts with an effective stress characterization procedure by introducing a length-scale concept. With it, a traction-based stress separation procedure is then presented to provide a consistent characterization of stresses from various sources based on their length scale. Their relative contributions to fracture driving force are then quantified in terms of their characteristic length scales. Special attention is given to the implications of the length-scale argument on both analysis and treatment of welding residual stresses in fracture assessment. A series of examples is provided to demonstrate how the present developments can be applied for treating not only secondary stresses but also externally applied stresses, as well as their combined effects on the structural integrity of engineering components

  4. Nanostructural optimization of silicon/PEDOT:PSS hybrid solar cells for performance improvement

    International Nuclear Information System (INIS)

    Wang, Yanzhou; Shao, Pengfei; Li, Yali; Li, Junshuai; He, Deyan; Chen, Qiang

    2017-01-01

    In this paper, an inverted silicon (Si) nanopyramid (iSiNP) surface structure with low aspect ratio and remarkable antireflection is developed through sequential treatments of NaOH and HF/CH 3 COOH/HNO 3 solutions to Si nanowire (SiNW)-textured Si wafers, which are prepared by traditional electroless chemical etching. The iSiNP/PEDOT:PSS hybrid solar cell is fabricated through conformally spin-coating poly(3.4-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) onto the iSiNPs; it exhibits enhanced device performance owing to the improved junction and contact quality as compared to the SiNW/PEDOT:PSS counterpart. A power conversion efficiency (PCE) of 9.6% mainly contributed from an increased fill factor (FF) of 0.61 and improved open circuit voltage ( V oc ) of 0.53 V is delivered by the iSiNP/PEDOT:PSS solar cell. As a comparison, the SiNW/PEDOT:PSS structure delivers a 7.1% PCE with a FF of 0.45 and V oc of 0.46 V. Considering the submicro-scale characteristic dimensions, iSiNPs are expected to be applicable to highly efficient thin film Si/PEDOT:PSS hybrid solar cells. (paper)

  5. PSS: An approach to sustainable innovation

    DEFF Research Database (Denmark)

    produktionsomkostninger. Produkt/Service-systemer by-der på en oplagt mulighed for at virksomheder kan sikre sig deres fremtid. Introduktion til Produkt/Service-systemer Produkt/service-systemer (PSS) er en innovationsstrategi, hvor en større integration af produkter og services har potentiale til at afkoble den...... eneste mål for PSS. Der hvor de store effekter kan høstes af PSS, er imidlertid at denne tankegang giver flere frihedsgrader i udviklingsarbejdet. Ved at integrere udvikling af produkter og services kan man få øje på nye måder at opfylde kundernes behov kan opfyldes og grundlag dannes for nye produkter......, services og for-retningsmuligheder....

  6. Scales tell a story on the stress history of fish.

    Science.gov (United States)

    Aerts, Johan; Metz, Juriaan Rogier; Ampe, Bart; Decostere, Annemie; Flik, Gert; De Saeger, Sarah

    2015-01-01

    Fish faced with stressful stimuli launch an endocrine stress response through activation of the hypothalamic-pituitary-interrenal (HPI-) axis to release cortisol into the blood. Scientifically validated biomarkers to capture systemic cortisol exposure over longer periods of time are of utmost importance to assess chronic stress in governmental, wildlife, aquaculture and scientific settings. Here we demonstrate that cortisol in scales of common carp (Cyprinus carpio L.) is the long-sought biomarker for chronic stress. Undisturbed (CTR) and daily stressed (STRESS) carp were compared. Dexamethasone (DEX) or cortisol (CORT) fed fish served as negative and positive controls, respectively. Scale cortisol was quantified with a validated ultra-performance liquid chromatography tandem mass spectrometry method. An increase in scale cortisol content was found in STRESS and CORT but not in CTR and DEX fish. Scale cortisol content reflects its accumulation in a stressor and time dependent manner and validates the scale cortisol content as biomarker for chronic stress. Plasma analyses confirmed that (i) CTR, DEX and CORT treatments were effective, (ii) plasma cortisol of STRESS fish showed no signs of chronic HPI-axis activation, and (iii) plasma cortisol is a poor predictor for chronic stress. The expression of HPI key genes crf, pomc, and star were up-regulated in STRESS fish in the absence of a plasma cortisol response, as was the target gene of cortisol encoding subunit α1 of the Na+/K+-ATPase in gills. When lost, scales of fish regenerate fast. Regenerated scales corroborate our findings, offering (i) unsurpassed time resolution for cortisol incorporation and as such for stressful events, and (ii) the possibility to investigate stress in a well defined and controlled environment and time frame creating novel opportunities for bone physiological research. We conclude that the cortisol content in ontogenetic and regenerated scales is an innovative biomarker for chronic

  7. Understanding the Capacitance of PEDOT:PSS

    DEFF Research Database (Denmark)

    Volkov, Anton V.; Wijeratne, Kosala; Mitraka, Evangelia

    2017-01-01

    Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is the most studied and explored mixed ion-electron conducting polymer system. PEDOT:PSS is commonly included as an electroactive conductor in various organic devices, e.g., supercapacitors, displays, transistors, and energy......-converters. In spite of its long-term use as a material for storage and transport of charges, the fundamentals of its bulk capacitance remain poorly understood. Generally, charge storage in supercapacitors is due to formation of electrical double layers or redox reactions, and it is widely accepted that PEDOT...

  8. Scaling of reactor cavity wall loads and stresses

    International Nuclear Information System (INIS)

    Bohachevsky, I.O.

    1977-11-01

    Scalings of reactor cavity wall loads and stresses are determined by deriving an analytic expression in terms of relevant parameters for each loading induced in the reactor cavity walls by fuel pellet microexplosion and by deriving associated expressions relating resulting stresses to shell thicknesses. Also identified are problems that require additional investigations to obtain satisfactory explicit stress estimates for the reactor cavity walls

  9. A Tool for Conceptualising in PSS development

    DEFF Research Database (Denmark)

    Matzen, Detlef; McAloone, Timothy Charles

    2006-01-01

    This paper introduces a tool for conceptualising in the development of product/servicesystems (PSS), based upon the modelling of service activities. Our argumentation is built on two previous articles by the same author, previously presented at the 16. Symposium “Design for X” [1] and the 9th Int...... the integrated consideration of the customers’ activities, possible PSS offerings and beneficial partnering options (i.e. between different supplier companies) within the delivery value chain.......This paper introduces a tool for conceptualising in the development of product/servicesystems (PSS), based upon the modelling of service activities. Our argumentation is built on two previous articles by the same author, previously presented at the 16. Symposium “Design for X” [1] and the 9th...... International Design Conference [2]. In this contribution, we take the step from a fundamental understanding of the phenomenon to creating a normative exploitation of this understanding for PSS concept development. The developed modelling technique is based on the Customer Activity Cycle (CAC) model...

  10. Construction and preliminary validation of the Barcelona Immigration Stress Scale.

    Science.gov (United States)

    Tomás-Sábado, Joaquín; Qureshi, Adil; Antonin, Montserrat; Collazos, Francisco

    2007-06-01

    In the study of mental health and migration, an increasing number of researchers have shifted the focus away from the concept of acculturation towards the stress present in the migratory experience. The bulk of research on acculturative stress has been carried out in the United States, and thus the definition and measurement of the construct has been predicated on that cultural and demographic context, which is of dubious applicability in Europe in general, and Spain in particular. Further, some scales have focused on international students, which down-played the importance of the migratory process, because it deals with a special subset of people who are not formally immigrating. The Barcelona Immigration Stress Scale was developed to measure acculturative stress appropriate to immigrants in Spain, using expert and focus group review and has 42 items. The scale shows acceptable internal validity, and, consistent with other scales, suggests that immigration stress is a complex construct.

  11. [Nursery Teacher's Stress Scale (NTSS): reliability and validity].

    Science.gov (United States)

    Akada, Taro

    2010-06-01

    This study describes the development and evaluation of the Nursery Teacher's Stress Scale (NTSS), which explores the relation between daily hassles at work and work-related stress. In Analysis 1, 29 items were chosen to construct the NTSS. Six factors were identified: I. Stress relating to child care; II. Stress from human relations at work; III. Stress from staff-parent relations; IV. Stress from lack of time; V. Stress relating to compensation; and VI. Stress from the difference between individual beliefs and school policy. All these factors had high degrees of internal consistency. In Analysis 2, the concurrent validity of the NTSS was examined. The results showed that the NTSS total scores were significantly correlated with the Job Stress Scale-Revised Version (job stressor scale, r = .68), the Pre-school Teacher-efficacy Scale (r = -.21), and the WHO-five Well-Being Index Japanese Version (r = -.40). Work stresses are affected by several daily hassles at work. The NTSS has acceptable reliability and validity, and can be used to improve nursery teacher's mental health.

  12. Degradation and Its Control of Ultraviolet Avalanche Photodiodes Using PEDOT:PSS/ZnSSe Organic-Inorganic Hybrid Structure

    Science.gov (United States)

    Abe, Tomoki; Uchida, Shigeto; Tanaka, Keita; Fujisawa, Takanobu; Kasada, Hirofumi; Ando, Koshi; Akaiwa, Kazuaki; Ichino, Kunio

    2018-05-01

    We investigated device degradation in PEDOT:PSS/ZnSSe organic-inorganic hybrid ultraviolet avalanche photodiodes (UV-APDs). ZnSSe/n-GaAs wafers were grown by molecular beam epitaxy, and PEDOT:PSS window layers were formed by inkjet technique. We observed rapid degradation with APD-mode stress (˜ 30 V) in the N2 (4 N) atmosphere, while we observed no marked change in forward bias current stress and photocurrent stress. In the case of a vacuum condition, we observed no detectable degradation in the dark avalanche current with APD-mode stress. Therefore, the degradation in the PEDOT:PSS/ZnSSe interface under the APD-mode stress was caused by the residual water vapor or oxygen in the N2 atmosphere and could be controlled by vacuum packaging.

  13. An Association between College Students' Health Promotion Practices and Perceived Stress

    Science.gov (United States)

    Li, Ying; Lindsey, Billie J.

    2013-01-01

    This study was undertaken to gain a better understanding of health promotion practices among college students and the relationship of stress and the practice of various health behaviors. Method: In Fall 2008, 319 students from a mid-size university participated in a cross-sectional survey utilizing the Perceived Stress Scale (PSS) and the Health…

  14. The use of self-Reiki for stress reduction and relaxation.

    Science.gov (United States)

    Bukowski, Elaine L

    2015-09-01

    More than one-third of college students reported the desire for stress reduction techniques and education. The purpose of this study was to determine the effects of a 20-week structured self-Reiki program on stress reduction and relaxation in college students. Students were recruited from Stockton University and sessions were conducted in the privacy of their residence. Twenty students completed the entire study consisting of 20 weeks of self-Reiki done twice weekly. Each participant completed a Reiki Baseline Credibility Scale, a Reiki Expectancy Scale, and a Perceived Stress Scale (PSS) after acceptance into the study. The PSS was completed every four weeks once the interventions were initiated. A global assessment questionnaire was completed at the end of the study. Logs summarizing the outcome of each session were submitted at the end of the study. With the exception of three participants, participants believed that Reiki is a credible technique for reducing stress levels. Except for two participants, participants agreed that Reiki would be effective in reducing stress levels. All participants experienced stress within the month prior to completing the initial PSS. There was a significant reduction in stress levels from pre-study to post-study. There was a correlation between self-rating of improvement and final PSS scores. With one exception, stress levels at 20 weeks did not return to pre-study stress levels. This study supports the hypothesis that the calming effect of Reiki may be achieved through the use of self-Reiki.

  15. Construction of the Examination Stress Scale for Adolescent Students

    Science.gov (United States)

    Sung, Yao-Ting; Chao, Tzu-Yang

    2015-01-01

    The tools used for measuring examination stress have three main limitations: sample selected, sample sizes, and measurement contents. In this study, we constructed the Examination Stress Scale (ExamSS), and 4,717 high school students participated in this research. The results indicate that ExamSS has satisfactory reliability, construct validity,…

  16. Pseudospark switches (PSS) for pulsed power applications

    Energy Technology Data Exchange (ETDEWEB)

    Heine, F; Prucker, U; Frank, K; Goertler, A; Schwandner, A; Tkotz, R; Hoffmann, D H.H.; Christiansen, J [Univ. of Erlangen (Germany). Physics Dept. I

    1997-12-31

    Based on the pseudospark discharge, a low pressure gas discharge in a special geometry, fast closing switches for different pulsed power applications have been designed. Medium power PSS ({<=} 30 kA peak current) were used in laser circuits whereas high current PSS are tested successfully in high current pulsed power applications ({<=} 200 kA). For currents of a few kA the discharge is supported by cathode spots on the cold cathode surface. For higher currents, anode activity is observed too. Inserting semiconductor material seems not only to suppress high erosive spot formation but to support diffuse large-area electrode emission. A different approach to solving the problem of lowering the erosion rate is the multichannel PSS (MUPS). In order to distribute the discharge current to more than one single channel, three or more discharge channels are radial or coaxial arranged. With regard to high voltage applications the maximum hold-off voltage was increased by adding an intermediate electrode. (author). 1 figs., 12 refs.

  17. An approach to an acute emotional stress reference scale.

    Science.gov (United States)

    Garzon-Rey, J M; Arza, A; de-la-Camara, C; Lobo, A; Armario, A; Aguilo, J

    2017-06-16

    The clinical diagnosis aims to identify the degree of affectation of the psycho-physical state of the patient as a guide to therapeutic intervention. In stress, the lack of a measurement tool based on a reference makes it difficult to quantitatively assess this degree of affectation. To define and perform a primary assessment of a standard reference in order to measure acute emotional stress from the markers identified as indicators of the degree. Psychometric tests and biochemical variables are, in general, the most accepted stress measurements by the scientific community. Each one of them probably responds to different and complementary processes related to the reaction to a stress stimulus. The reference that is proposed is a weighted mean of these indicators by assigning them relative weights in accordance with a principal components analysis. An experimental study was conducted on 40 healthy young people subjected to the psychosocial stress stimulus of the Trier Social Stress Test in order to perform a primary assessment and consistency check of the proposed reference. The proposed scale clearly differentiates between the induced relax and stress states. Accepting the subjectivity of the definition and the lack of a subsequent validation with new experimental data, the proposed standard differentiates between a relax state and an emotional stress state triggered by a moderate stress stimulus, as it is the Trier Social Stress Test. The scale is robust. Although the variations in the percentage composition slightly affect the score, but they do not affect the valid differentiation between states.

  18. Scale effect in fatigue resistance under complex stressed state

    International Nuclear Information System (INIS)

    Sosnovskij, L.A.

    1979-01-01

    On the basis the of the fatigue failure statistic theory obtained is the formula for calculated estimation of probabillity of failure under complex stressed state according to partial probabilities of failure under linear stressed state with provision for the scale effect. Also the formula for calculation of equivalent stress is obtained. The verification of both formulae using literary experimental data for plane stressed state torsion has shown that the error of estimations does not exceed 10% for materials with the ultimate strength changing from 61 to 124 kg/mm 2

  19. Model Calibration of Exciter and PSS Using Extended Kalman Filter

    Energy Technology Data Exchange (ETDEWEB)

    Kalsi, Karanjit; Du, Pengwei; Huang, Zhenyu

    2012-07-26

    Power system modeling and controls continue to become more complex with the advent of smart grid technologies and large-scale deployment of renewable energy resources. As demonstrated in recent studies, inaccurate system models could lead to large-scale blackouts, thereby motivating the need for model calibration. Current methods of model calibration rely on manual tuning based on engineering experience, are time consuming and could yield inaccurate parameter estimates. In this paper, the Extended Kalman Filter (EKF) is used as a tool to calibrate exciter and Power System Stabilizer (PSS) models of a particular type of machine in the Western Electricity Coordinating Council (WECC). The EKF-based parameter estimation is a recursive prediction-correction process which uses the mismatch between simulation and measurement to adjust the model parameters at every time step. Numerical simulations using actual field test data demonstrate the effectiveness of the proposed approach in calibrating the parameters.

  20. Understanding the Experiences of Women, Graduate Student Stress, and Lack of Marital/Social Support: A Mixed Method Inquiry

    Science.gov (United States)

    Williams-Tolliver, Sarah D.

    2010-01-01

    The purpose of this study was to explore how women attending graduate degree programs in public universities in Virginia were affected by such issues as stress and lack of marital/social support. Utilizing a mixed method approach for data collection, 23 participants completed demographic data, an essay response, and the PSS-10 Stress Scale; 8 were…

  1. Development of the Abbreviated Masculine Gender Role Stress Scale.

    Science.gov (United States)

    Swartout, Kevin M; Parrott, Dominic J; Cohn, Amy M; Hagman, Brett T; Gallagher, Kathryn E

    2015-06-01

    Data gathered from 6 independent samples (n = 1,729) that assessed men's masculine gender role stress in college and community males were aggregated used to determine the reliability and validity of an abbreviated version of the Masculine Gender Role Stress (MGRS) Scale. The 15 items with the highest item-to-total scale correlations were used to create an abbreviated MGRS Scale. Psychometric properties of each of the 15 items were examined with item response theory (IRT) analysis, using the discrimination and threshold parameters. IRT results showed that the abbreviated scale may hold promise at capturing the same amount of information as the full 40-item scale. Relative to the 40-item scale, the total score of the abbreviated MGRS Scale demonstrated comparable convergent validity using the measurement domains of masculine identity, hypermasculinity, trait anger, anger expression, and alcohol involvement. An abbreviated MGRS Scale may be recommended for use in clinical practice and research settings to reduce cost, time, and patient/participant burden. Additionally, IRT analyses identified items with higher discrimination and threshold parameters that may be used to screen for problematic gender role stress in men who may be seen in routine clinical or medical practice. (c) 2015 APA, all rights reserved).

  2. Teacher Stress Inventory: validation of the Greek version and perceived stress levels among 3,447 educators

    OpenAIRE

    Kourmousi N; Darviri C; Varvogli L; Alexopoulos EC

    2015-01-01

    Ntina Kourmousi, Christina Darviri, Liza Varvogli, Evangelos C Alexopoulos School of Medicine, University of Athens, Athens, Greece Background: The Teacher Stress Inventory (TSI) is an instrument for measuring occupational stress in teachers. This study aimed to translate and adapt it for use in Greece, and then assess its reliability and validity. Methods: The Greek versions of the TSI and the 14-item Perceived Stress Scale (PSS-14) were posted on all Greek educators' official sites...

  3. Perceived Stress in Family Caregivers of Individuals With Mental Illness.

    Science.gov (United States)

    Masa'Deh, Rami

    2017-06-01

    The current study aimed to measure the stress levels of family caregivers of individuals with mental illness and compare their stress levels according to the diagnosis and other sociodemographic characteristics. The sample comprised 310 family caregivers of individuals with mental illness in Jordan. Family caregivers completed a demographic checklist and the Arabic version of the Perceived Stress Scale 10-Item (PSS-10) questionnaire. A significant difference was found in PSS-10 levels among family caregivers according to gender, diagnosis of their family member, and time since diagnosis. Female caregivers reported significantly higher stress levels than male caregivers. Family members of individuals with schizophrenia reported the highest stress levels (p family caregivers and time since diagnosis. Investigating stress levels in family members of individuals with mental illness may be helpful when designing interventions to reduce such stress. [Journal of Psychosocial Nursing and Mental Health Services, 55(6), 30-35.]. Copyright 2017, SLACK Incorporated.

  4. Measurement of Perceived Stress Among Pregnant Women: A Comparison of Two Different Instruments.

    Science.gov (United States)

    Solivan, Amber E; Xiong, Xu; Harville, Emily W; Buekens, Pierre

    2015-09-01

    Assess the amount of agreement between the classification of stress from the Perceived Stress Scale (PSS) and the Assessment of Stress portion of the Prenatal Psychosocial Profile (PPP) among pregnant women. A secondary data analysis on a cross-sectional study of 301 pregnant women from the New Orleans and Baton Rouge areas who were exposed to Hurricane Katrina was conducted. Women with complete data (219) were analyzed. Women scoring in the third tertile of each instrument were compared. The kappa statistic was used to assess agreement between instruments. Additional comparisons were made with three instruments that measure other important psychosocial constructs that could be related to stress: the Edinburgh Depression Scale (EDS) and the Assessments of Support (partner and other support) and Self-Esteem from the PPP. No significant difference was found between the two tests. The PSS and the PPP were both statistically significantly correlated to each other (ρ = 0.71, p < 0.01). Thirty-five women were classified discordantly resulting in a Kappa Coefficient of 0.61 (95% CI 0.50-0.72, p < 0.01). No significant differences were found between these two instruments in correlation with the EDS (PPP, r = 0.76; PSS, r = 0.72; p < 0.01 for each), partner support (PPP, r = -0.47; PSS r = -0.46; p < 0.01 for each), other support (PPP, r = -0.31; PSS r = -0.32; p < 0.01 for each) and self-esteem (PPP, r = -0.41; PSS, r = -0.52; p < 0.01 for each), respectively. Given the similarities between the PSS and PPP, researchers are encouraged to choose and administer one instrument to participants, or to use the instruments in combination as an external reliability check.

  5. Directives to support the design of changeable (I)PSS

    NARCIS (Netherlands)

    Pereira Pessoa, Marcus Vinicius; Jauregui Becker, Juan Manuel; Maier, Anja; Skec, Stanko; Kim, Harrison; Kokkolaras, Michael; Oehmen, Josef; Fadel, Georges; Salustri, Filippo; Van der Loos, Mike

    2017-01-01

    Product service models (PSM) benefits are not limited to its providers and costumers, but the whole society might also take advantage from its sustainability impact. Achieving these benefits, though, require changeable product service systems ((I)PSS). Changeability means the (I)PSS' modules have

  6. The Curious Out-of-Plane Conductivity of PEDOT : PSS

    NARCIS (Netherlands)

    van de Ruit, Kevin; Katsouras, Ilias; Bollen, Dirk; van Mol, Ton; Janssen, Rene A. J.; de Leeuw, Dago M.; Kemerink, Martijn

    2013-01-01

    For its application as transparent conductor in light-emitting diodes and photovoltaic cells, both the in-plane and out-of-plane conductivity of PEDOT:PSS are important. However, studies into the conductivity of PEDOT:PSS rarely address the out-of-plane conductivity and those that do, report widely

  7. Bridging scales of crustal stress patterns using the new World Stress Map

    Science.gov (United States)

    Heidbach, O.; Rajabi, M.; Cui, X.; Fuchs, K. W.; Mueller, B.; Reinecker, J.; Reiter, K.; Tingay, M. R. P.; Wenzel, F.; Xie, F.; Ziegler, M.; Zoback, M. D.; Zoback, M. L.

    2017-12-01

    Knowledge of the contemporary crustal stress field is a key parameter for the understanding of geodynamic processes such as global plate tectonics and the earthquake cycle. It is also an essential parameter for our sustainable and safe usage of Earth's resources, which is a major challenge for energy security in the 21st century. Since 1986, the World Stress Map (WSM) project has systematically compiled present-day stress information and provides a unique public domain global database. It is a long-term project based on an international network of partners from academia and industry. All data are public and available on the project website at world-stress-map.org. For the 30th anniversary of the project a new database has been compiled, containing double the amount of data records (n=42,870) including new data records from almost 4,000 deep boreholes. The new compilation focused on areas with previously sparse data coverage in order to resolve the stress pattern on different spatial scales. The significantly higher data density can now be used to resolve stress pattern heterogeneities on regional and local scales, as well as with depth in some regions. We present three results derived from the new WSM compilation: 1.) The global comparison between absolute plate motion and the mean of the orientation of maximum horizontal stress SHmax on a regular grid shows that there is still a correlation for the North and South America plate, but deviations from this general trend are now also clearly resolved. 2.) The variability of the crustal stress pattern changes when zooming in from plate-wide scale down to basin scale at 100 km. We show examples for Eastern Australia, Oklahoma and Central Europe. This regional and local variability of the stress pattern can be used as a proxy to identify and quantify regional and local stress sources by means of geomechanical-numerical models of the 3D stress tensor. 3.) Finally we present briefly the general concept of a multi-stage 3D

  8. The empowerment potential of public sector software (PSS

    Directory of Open Access Journals (Sweden)

    Pradip Ninan Thomas

    2012-03-01

    Full Text Available Investigations into the potential for public sector software (PSS to empower citizens are at a very nascent stage. This article explores the theoretical basis for, and practical advantages of, PSS, in the making of an informed and pro-active citizenry. Using the example of the emerging PSS movement in India and in particular the ICT literacy movement in Kerala, South India, it argues, that access to and use of software based on the principles of free and open source has the potential to contribute to an empowered citizenry. However the very concept of PSS is contested by major private software companies given that they stand to lose from public investments that are based on open standards. The article argues that PSS can contribute to the making of an ‘information commons’ and that the need of the hour is for innovative and creative solutions to the information deficits faced by communities in India and elsewhere.

  9. [Spanish adaptation of the Stress Manifestations Scale of the Student Stress Inventory (SSI-SM)].

    Science.gov (United States)

    Escobar Espejo, Milagros; Blanca, María J; Fernández-Baena, F Javier; Trianes Torres, María Victoria

    2011-08-01

    The aim of the present study was to translate into Spanish and to describe the psychometric properties of the Stress Manifestations Scale of the Student Stress Inventory (SSI-SM), developed by Fimian, Fastenau, Tashner and Cross to identify the main manifestations of stress in adolescents. The scale was applied to a sample of 1,002 pupils from years one and two of Secondary Education. The paper reports the factor structure, an item analysis, the internal consistency, differences by sex and academic year, external evidence of validity, and norms for scoring the scale. The results reveal a factor structure based on three first-order factors (emotional manifestations, physiological manifestations and behavioural manifestations) and one second-order factor (indicative of stress manifestations). In terms of external validity, there was a positive association with measures of perceived stress, aggressiveness, internalized/externalized symptoms, and a negative association with life satisfaction. The results show that the scale is an adequate tool for evaluating stress manifestations in adolescents.

  10. Align and random electrospun mat of PEDOT:PSS and PEDOT:PSS/RGO

    Science.gov (United States)

    Sarabi, Ghazale Asghari; Latifi, Masoud; Bagherzadeh, Roohollah

    2018-01-01

    In this research work we fabricated two ultrafine conductive nanofibrous layers to investigate the materilas composition and their properties for the preparation of supercapacitor materials application. In first layer, a polymer and a conductive polymer were used and second layer was a composition of polymer, conductive polymer and carbon-base material. In both cases align and randomized mat of conductive nanofibers were fabricated using electrospinning set up. Conductive poly (3,4-ethylenedioxythiophene)/ polystyrene sulfonate (PEDOT:PSS) nanofibers were electrospun by dissolving fiber-forming polymer and polyvinyl alcohol (PVA) in an aqueous dispersion of PEDOT:PSS. The effect of addition of reduced graphene oxide (RGO) was considered for nanocomposite layer. The ultrafine conductive polymer fibers and conductive nanocomposite fibrous materials were also fabricated using an electrospinning process. A fixed collector and a rotating drum were used for random and align nanofibers production, respectively. The resulted fibers were characterized and analyzed by SEM, FTIR and two-point probe conductivity test. The average diameter of nanofibers measured by ImageJ software indicated that the average fiber diameter for first layer was 100 nm and for nanocomposite layer was about 85 nm. The presence of PEDOT:PSS and RGO in the nanofibers was confirmed by FT-IR spectroscopy. The conductivity of align and random layers was characterized. The conductivity of PEDOT:PSS nanofibers showed higher enhancement by addition of RGO in aqueous dispersion. The obtained results showed that alignment of fibrous materials can be considered as an engineering tool for tuning the conductivity of fibrous materials for many different applications such as supercapacitors, conductive and transparent materials.

  11. Framing design research for service orientation through PSS approaches

    DEFF Research Database (Denmark)

    Sakao, Tomohiko; Sandström, Gunilla Ölundh; Matzen, Detlef

    2009-01-01

    on the literature analysis, the authors present three crucial dimensions for service oriented design research, i.e. an offer dimension representing products and services, a provider dimension, and a customer/user dimension. In addition, three research targets are proposed; PSS-offer modelling, PSS development......, and PSS potential. Furthermore, several promising future research directions are identified. These include evaluating economic consequences or environmental benefits, establishing terminology, organizational issues, and developing methods and tools to support designers. The boundaries to other research...... fields are getting blurry and many aspects of other professionalisms must be taken into account. Thus, there is especially need in future research to open towards other research areas....

  12. Renal diagnostic nuclear medicine procedures in progressive systemic scleroderma (PSS)

    Energy Technology Data Exchange (ETDEWEB)

    Ammari, B.; Hotze, A.; Gruenwald, F.; Biersack, H.J.; Blitz, H.; Kuester, W.; Kreysel, H.W.

    1989-02-01

    The involvement of kidneys in progressive systemic scleroderma (PSS) is one of the most frequent causes of death in this disease. Using clinical criteria and laboratory tests only the frequency of kidney involvement would be clearly underestimated. Invasive diagnostic procedures such as biopsy and angiography can not be applied in those patients. Nuclear medicine techniques (hippurate clearance, DMSA-scan), however, offer non invasive and sensitive methods in the diagnosis of renal involvement in PSS patients. In our study 46 of 76 patients (60%) revealed pathologic findings. The mentioned diagnostic techniques show a high sensitivity and are in agreement with pathological findings described in PSS.

  13. Renal diagnostic nuclear medicine procedures in progressive systemic scleroderma (PSS)

    International Nuclear Information System (INIS)

    Ammari, B.; Hotze, A.; Gruenwald, F.; Biersack, H.J.; Blitz, H.; Kuester, W.; Kreysel, H.W.

    1989-01-01

    The involvement of kidneys in progressive systemic scleroderma (PSS) is one of the most frequent causes of death in this disease. Using clinical criteria and laboratory tests only the frequency of kidney involvement would be clearly underestimated. Invasive diagnostic procedures such as biopsy and angiography can not be applied in those patients. Nuclear medicine techniques (hippurate clearance, DMSA-scan), however, offer non invasive and sensitive methods in the diagnosis of renal involvement in PSS patients. In our study 46 of 76 patients (60%) revealed pathologic findings. The mentioned diagnostic techniques show a high sensitivity and are in agreement with pathological findings described in PSS. (orig.) [de

  14. Chemical sensing of plant stress at the ecosystem scale

    Directory of Open Access Journals (Sweden)

    T. Karl

    2008-09-01

    Full Text Available Significant ecosystem-scale emissions of methylsalicylate (MeSA, a semivolatile plant hormone thought to act as the mobile signal for systemic acquired resistance (SAR, were observed in an agroforest. Our measurements show that plant internal defence mechanisms can be activated in response to temperature stress and are modulated by water availability on large scales. Highest MeSA fluxes (up to 0.25 mg/m2/h were observed after plants experienced ambient night-time temperatures of ~7.5°C followed by a large daytime temperature increase (e.g. up to 22°C. Under these conditions estimated night-time leaf temperatures were as low as ~4.6°C, likely inducing a response to prevent chilling injury. Our observations imply that plant hormones can be a significant component of ecosystem scale volatile organic compound (VOC fluxes (e.g. as high as the total monoterpene (MT flux and therefore contribute to the missing VOC budget. If generalized to other ecosystems and different types of stresses these findings suggest that semivolatile plant hormones have been overlooked by investigations of the impact of biogenic VOCs on aerosol formation events in forested regions. Our observations show that the presence of MeSA in canopy air serves as an early chemical warning signal indicating ecosystem-scale stresses before visible damage becomes apparent. As a chemical metric, ecosystem emission measurements of MeSA in ambient air could therefore support field studies investigating factors that adversely affect plant growth.

  15. Water stress strengthens mutualism among ants, trees, and scale insects.

    Directory of Open Access Journals (Sweden)

    Elizabeth G Pringle

    2013-11-01

    Full Text Available Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant-plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant-plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism.

  16. Water Stress Strengthens Mutualism Among Ants, Trees, and Scale Insects

    Science.gov (United States)

    Pringle, Elizabeth G.; Akçay, Erol; Raab, Ted K.; Dirzo, Rodolfo; Gordon, Deborah M.

    2013-01-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant–plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant–plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism. PMID:24223521

  17. Water stress strengthens mutualism among ants, trees, and scale insects.

    Science.gov (United States)

    Pringle, Elizabeth G; Akçay, Erol; Raab, Ted K; Dirzo, Rodolfo; Gordon, Deborah M

    2013-11-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant-plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant-plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism.

  18. Autoclave Sterilization of PEDOT:PSS Electrophysiology Devices.

    Science.gov (United States)

    Uguz, Ilke; Ganji, Mehran; Hama, Adel; Tanaka, Atsunori; Inal, Sahika; Youssef, Ahmed; Owens, Roisin M; Quilichini, Pascale P; Ghestem, Antoine; Bernard, Christophe; Dayeh, Shadi A; Malliaras, George G

    2016-12-01

    Autoclaving, the most widely available sterilization method, is applied to poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) electrophysiology devices. The process does not harm morphology or electrical properties, while it effectively kills E. coli intentionally cultured on the devices. This finding paves the way to widespread introduction of PEDOT:PSS electrophysiology devices to the clinic. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Stress analysis and scaling studies of corium crusts

    International Nuclear Information System (INIS)

    Feng, Z.; Engelstad, R.L.; Lovell, E.G.; Corradini, M.L.

    1992-01-01

    In the event of a severe accident in a LWR, water may be input to cool the molten mixture of fuel and concrete. A number of structural models are developed and used to predict whether a crust will be formed and remain stable between the melt and water. Bending stresses and membrane stresses due to pressure loadings and the temperature differential are considered in the analyses to investigate the stability of the crust as a function of the time, thickness and span. The results from parametric studies show the conditions under which a crust could develop, and how such structural models could be used to determine scaling effects and provide correlations to prototypic accident situations. (orig.)

  20. Pressure suppression system (PSS) for nuclear ships. Experimental results obtained at the GKSS PSS-test-facillity

    International Nuclear Information System (INIS)

    Aust, E.; Niemann, H.R.; Schwan, H.; Vollbrandt, J.

    1978-01-01

    The PSS-test facility is shortly presented which was designed to show experimentally the operation of the pressure suppression containment for the NCS 80 concept. The results of the experimental LOCA-simulation tests in the PSS-test facility are illustrated by diagrams. The observed phenomena as chugging and pessure oscillations immediately after vent clearing are reported as well as the thermohydraulic loadings of the total system. Finally a short view is given on the future test program

  1. Enhancement of Thermoelectric Properties of PEDOT:PSS and Tellurium-PEDOT:PSS Hybrid Composites by Simple Chemical Treatment

    Science.gov (United States)

    Jin Bae, Eun; Hun Kang, Young; Jang, Kwang-Suk; Yun Cho, Song

    2016-01-01

    The thermoelectric properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and tellurium-PEDOT:PSS (Te-PEDOT:PSS) hybrid composites were enhanced via simple chemical treatment. The performance of thermoelectric materials is determined by their electrical conductivity, thermal conductivity, and Seebeck coefficient. Significant enhancement of the electrical conductivity of PEDOT:PSS and Te-PEDOT:PSS hybrid composites from 787.99 and 11.01 to 4839.92 and 334.68 S cm-1, respectively was achieved by simple chemical treatment with H2SO4. The power factor of the developed materials could be effectively tuned over a very wide range depending on the concentration of the H2SO4 solution used in the chemical treatment. The power factors of the developed thermoelectric materials were optimized to 51.85 and 284 μW m-1 K-2, respectively, which represent an increase of four orders of magnitude relative to the corresponding parameters of the untreated thermoelectric materials. Using the Te-PEDOT:PSS hybrid composites, a flexible thermoelectric generator that could be embedded in textiles was fabricated by a printing process. This thermoelectric array generates a thermoelectric voltage of 2 mV using human body heat.

  2. Towards assessing Product/Service-Systems (PSS) within the Danish maritime industry: A PSS positioning map

    DEFF Research Database (Denmark)

    Hsuan, Juliana; Andersen, Jakob Axel Bejbro; Bey, Niki

    2012-01-01

    In response to requirements resulting from a changing business landscape from solely physical-product-based value creation towards performance-based value creation, this paper presents a questionnaire-based matrix, the PSS Categorization Matrix, that is developed in order to help organizations find...... their position in terms of the balance between product-related and service-related activities. Judging from a workshop carried out with companies from the maritime industry and researchers in the area, the approach seems promising, but requires improvements on questionnaire and Matrix. These need to incorporate...... further improvements regarding the factor of time and the applicability related to product/service portfolios, as opposed to single product/services. The authors already plan further research on the identified issues....

  3. Patterns and determinants of stress among consultant physicians working in Saudi Arabia.

    Science.gov (United States)

    Alosaimi, Fahad D; Alawad, Hossam S; Alamri, Ayedh K; Saeed, Abdullah I; Aljuaydi, Khalid A; Alotaibi, Alwaleed S; Alotaibi, Khalid M; Alfaris, Eiad A

    2018-01-01

    Physicians experience several work-related stressors that have been mounting up in recent decades. This study aimed to examine perceived stress and its risk factors and consequences among consultant physicians in Saudi Arabia. A cross-sectional study was conducted from November 2014 to March 2015 among physicians who were assigned rank of consultant. The stress level was assessed using perceived stress scale (PSS). A total of 582 consultants participated. The average age was 46.9±7.9 years, 71% were males, 56% were Saudi, 15% were smokers, and 68% slept ≤6 hours per night. The median PSS score was 17 (interquartile range of 14-21), which represented 44% of maximum possible PSS score. The upper tertile of PSS score (represents a high stress level) was significantly associated with being younger, female, and Saudi. The majority (85%) considered job environment to be stressful and ~50% attributed that to a high workload and a noncooperative administration. In the year preceding this study, half of consultants frequently contemplated or even worked toward changing their medical institutes or even moving to work outside Saudi Arabia because of perception of a stressful working environment. Over the previous year, encountering life stressors, considering job environment as stressful and experiencing passive suicidal ideation, were significantly associated with higher levels of stress. In multivariate analysis, the following factors were independently associated with stress: female gender (odds ratio [OR]=2.41, 95% CI 1.58-3.70) and perceived stressful working environment (OR=3.66, 95% CI 1.87-7.17). Consultant physicians in Saudi Arabia experience moderate to high levels of perceived stress that are relatively comparable to physicians worldwide. A significant association was found between stress levels and both female gender and perception of a stressful working environment. Further studies are required to assess physician-based interventions and organization

  4. Energy level and thickness control on PEDOT:PSS layer for efficient planar heterojunction perovskite cells

    Science.gov (United States)

    Wang, Chunhua; Zhang, Chujun; Tong, Sichao; Xia, Huayan; Wang, Lijuan; Xie, Haipeng; Gao, Yongli; Yang, Junliang

    2018-01-01

    Efficient planar heterojunction perovskite solar cells (PHJ-PSCs) with an architecture of ITO/PEDOT:PSS/CH3NH3PbI3/PCBM/Al were fabricated by controlling the energy level and thickness of the PEDOT:PSS layer, where the PEDOT:PSS precursor was diluted with deionized water (H2O) and isopropyl alcohol (IPA), i.e. W-PEDOT:PSS and I-PEDOT:PSS. The performance parameters of the PHJ-PSCs showed soaring enhancement after employing W-PEDOT:PSS or I-PEDOT:PSS instead of pristine PEDOT:PSS (P-PEDOT:PSS), resulting in an increase of the power conversion efficiency (PCE) of W-PEDOT:PSS-based PHJ-PSCs to 15.60% from 11.95% for P-PEDOT:PSS-based PHJ-PSCs. The performance improvement results from two aspects. On the one hand, as compared to P-PEDOT:PSS, the occupied molecular orbital energy (HOMO) level of dilute PEDOT:PSS showed an impressive decrease and can well match the valence band of CH3NH3PbI3 film, resulting in less energy loss and a significant improvement in the open-circuit voltage (V oc). On the other hand, the dilute PEDOT:PSS could produce a thinner film as compared with the P-PEDOT:PSS, which also played an important role in the performance of the PHJ-PSCs. Furthermore, the electrochemical impedance spectroscopy (EIS) results indicated that the interface between perovskite and PEDOT:PSS was greatly improved by employing W-PEDOT:PSS or I-PEDOT:PSS, leading to an obvious decrease in the series resistance (R s) and an increase in the recombination resistance (R rec). The research demonstrated that diluting PEDOT:PSS with a common solvent, such as H2O and IPA, is a feasible low-temperature way of achieving efficient PHJ-PSCs.

  5. Modified stress intensity factor as a crack growth parameter applicable under large scale yielding conditions

    International Nuclear Information System (INIS)

    Yasuoka, Tetsuo; Mizutani, Yoshihiro; Todoroki, Akira

    2014-01-01

    High-temperature water stress corrosion cracking has high tensile stress sensitivity, and its growth rate has been evaluated using the stress intensity factor, which is a linear fracture mechanics parameter. Stress corrosion cracking mainly occurs and propagates around welded metals or heat-affected zones. These regions have complex residual stress distributions and yield strength distributions because of input heat effects. The authors previously reported that the stress intensity factor becomes inapplicable when steep residual stress distributions or yield strength distributions occur along the crack propagation path, because small-scale yielding conditions deviate around those distributions. Here, when the stress intensity factor is modified by considering these distributions, the modified stress intensity factor may be used for crack growth evaluation for large-scale yielding. The authors previously proposed a modified stress intensity factor incorporating the stress distribution or yield strength distribution in front of the crack using the rate of change of stress intensity factor and yield strength. However, the applicable range of modified stress intensity factor for large-scale yielding was not clarified. In this study, the range was analytically investigated by comparison with the J-integral solution. A three-point bending specimen with parallel surface crack was adopted as the analytical model and the stress intensity factor, modified stress intensity factor and equivalent stress intensity factor derived from the J-integral were calculated and compared under large-scale yielding conditions. The modified stress intensity was closer to the equivalent stress intensity factor when compared with the stress intensity factor. If deviation from the J-integral solution is acceptable up to 2%, the modified stress intensity factor is applicable up to 30% of the J-integral limit, while the stress intensity factor is applicable up to 10%. These results showed that

  6. Perceived stress and bruxism in university students.

    Science.gov (United States)

    Cavallo, Pierpaolo; Carpinelli, Luna; Savarese, Giulia

    2016-12-21

    Many studies have shown the correlation between bruxism and stress that affects the quality of life of university students. The present study highlights this correlation-for the first time-in a group of university students in Italy. We have investigated the prevalence of awake and asleep bruxism and its correlation with perceived stress in a group of 278 Italian undergraduate students (117 M). A self report questionnaire was constructed using a socio-demographic test, the Perceived Stress Scale (PSS) and the item n. 8 of the Fonseca Questionnaire for presence of bruxism. The perceived stress score using PSS-10 scale was 32.2 (SD 4.6, 95% CL 31.6-32.7) for all the subjects, with significant gender difference: M = 31.2 and F = 32.9 (P = 0.0019). The prevalence for awake bruxism was 37.9% (F = 40.8%; M = 34.2%,), while for sleep bruxism was 31.8% (F = 33.3%; M = 29.1%), both without significant gender difference. A positive correlation, with significant concordance and dependence, between stress score and awake bruxism was present for male students only. University students showed higher bruxism and stress levels compared to the general population, with higher stress for females, but, even if female students show higher stress, a correlation between stress and bruxism exists only for male gender. Further studies should be performed.

  7. Morphology, conductivity, and wetting characteristics of PEDOT:PSS thin films deposited by spin and spray coating

    Energy Technology Data Exchange (ETDEWEB)

    Zabihi, F.; Xie, Y.; Gao, S.; Eslamian, M., E-mail: Morteza.Eslamian@sjtu.edu.cn

    2015-05-30

    Highlights: • Nanostructure of spun-on and spray-on PEDOT:PSS thin films is studied. • A correlation is established between the film nanostructure and electrical conductivity. • Effect of process parameters is studied on the film characteristics. • A high solution concentration, high process temperature and multiple deposition layers are recommended. - Abstract: The goal of this paper is to study the characteristics of PEDOT:PSS thin films and the effects of varying the processing parameters on the structure, functionality, and surface wetting of spun-on and spray-on PEDOT:PSS thin films. PEDOT:PSS is a polymer mixture, which is electrically conductive and transparent and, therefore, is an attractive material for some optoelectronic applications, such as organic and perovskite solar cells. In this work, the films are fabricated using spin coating (a lab-scale method) and spray coating (an up-scalable method). The effects of spinning speed, drying time, and post-annealing temperature on spun-on samples and the effects of the substrate temperature and number of spray passes (deposition layers) on spray-on samples, as well as the effect of precursor solution concentration on both cases are investigated. Various characterization tools, such as AFM, SEM, XRD, confocal laser scanning microscopy (CLSM), and electrical conductivity measurements are used to determine the film roughness, thickness, structure, and morphology. The solution precursor physical data, such as contact angle on glass substrates, viscosity, and interfacial tension, are also obtained within a practical range of temperatures and concentrations. It is found that in both spin and spray coating routes, only well-controlled operating conditions result in the formation of conductive and defect-free PEDOT:PSS films. The formation of PEDOT:PSS thin films with small grains composed of PEDOT forming the core of the grains and PSS forming a shell or coating, which are evenly distributed in a PSS

  8. Morphology, conductivity, and wetting characteristics of PEDOT:PSS thin films deposited by spin and spray coating

    International Nuclear Information System (INIS)

    Zabihi, F.; Xie, Y.; Gao, S.; Eslamian, M.

    2015-01-01

    Highlights: • Nanostructure of spun-on and spray-on PEDOT:PSS thin films is studied. • A correlation is established between the film nanostructure and electrical conductivity. • Effect of process parameters is studied on the film characteristics. • A high solution concentration, high process temperature and multiple deposition layers are recommended. - Abstract: The goal of this paper is to study the characteristics of PEDOT:PSS thin films and the effects of varying the processing parameters on the structure, functionality, and surface wetting of spun-on and spray-on PEDOT:PSS thin films. PEDOT:PSS is a polymer mixture, which is electrically conductive and transparent and, therefore, is an attractive material for some optoelectronic applications, such as organic and perovskite solar cells. In this work, the films are fabricated using spin coating (a lab-scale method) and spray coating (an up-scalable method). The effects of spinning speed, drying time, and post-annealing temperature on spun-on samples and the effects of the substrate temperature and number of spray passes (deposition layers) on spray-on samples, as well as the effect of precursor solution concentration on both cases are investigated. Various characterization tools, such as AFM, SEM, XRD, confocal laser scanning microscopy (CLSM), and electrical conductivity measurements are used to determine the film roughness, thickness, structure, and morphology. The solution precursor physical data, such as contact angle on glass substrates, viscosity, and interfacial tension, are also obtained within a practical range of temperatures and concentrations. It is found that in both spin and spray coating routes, only well-controlled operating conditions result in the formation of conductive and defect-free PEDOT:PSS films. The formation of PEDOT:PSS thin films with small grains composed of PEDOT forming the core of the grains and PSS forming a shell or coating, which are evenly distributed in a PSS

  9. Cross-cultural validity of the masculine and Feminine Gender Role Stress scales

    NARCIS (Netherlands)

    van Well, S; Kolk, AM; Arrindell, WA

    The objective was to examine the usefulness of Dutch versions of the Masculine Gender Role Stress (MGRS; Eisler & Skidmore, 1987) Scale and the Feminine Gender Role Stress (Gillespie & Eisler, 1992) Scale in The Netherlands. Undergraduate students (N = 2,239) completed both gender role stress

  10. Durability of PEDOT: PSS-pentacene Schottky diode

    International Nuclear Information System (INIS)

    Kang, K S; Lim, H K; Cho, K Y; Han, K J; Kim, Jaehwan

    2008-01-01

    The durability and failure cause of a polymer Schottky diode made with PEDOT : PSS-pentacene were investigated. A polymer Schottky diode was fabricated by dissolving pentacene in N-methylpyrrolidone (NMP) and mixing with PEDOT : PSS. Pentacene solution having a maximum concentration of approximately 9.7 mmoles was prepared by simply stirring the solution at room temperature for 36 h. As the pentacene concentration increased, the absorption of the broad UV regime increased dramatically. However, absorption peaks of pentacene at 301 and 260 nm were not observed for the PEDOT : PSS-pentacene. A three-layered polymer Schottky diode was fabricated and its current-voltage (I-V) characteristic was evaluated. The current was reduced by 7% in the first 50 min and then stabilized during biased electrical field sweeps. After 500 and 800 min, catastrophic failure occurred. FESEM images revealed that the electrode damage caused catastrophic failure of the Schottky diode. (fast track communication)

  11. The Depression Anxiety Stress Scales-21 (DASS-21): further examination of dimensions, scale reliability, and correlates.

    Science.gov (United States)

    Osman, Augustine; Wong, Jane L; Bagge, Courtney L; Freedenthal, Stacey; Gutierrez, Peter M; Lozano, Gregorio

    2012-12-01

    We conducted two studies to examine the dimensions, internal consistency reliability estimates, and potential correlates of the Depression Anxiety Stress Scales-21 (DASS-21; Lovibond & Lovibond, 1995). Participants in Study 1 included 887 undergraduate students (363 men and 524 women, aged 18 to 35 years; mean [M] age = 19.46, standard deviation [SD] = 2.17) recruited from two public universities to assess the specificity of the individual DASS-21 items and to evaluate estimates of internal consistency reliability. Participants in a follow-up study (Study 2) included 410 students (168 men and 242 women, aged 18 to 47 years; M age = 19.65, SD = 2.88) recruited from the same universities to further assess factorial validity and to evaluate potential correlates of the original DASS-21 total and scale scores. Item bifactor and confirmatory factor analyses revealed that a general factor accounted for the greatest proportion of common variance in the DASS-21 item scores (Study 1). In Study 2, the fit statistics showed good fit for the bifactor model. In addition, the DASS-21 total scale score correlated more highly with scores on a measure of mixed depression and anxiety than with scores on the proposed specific scales of depression or anxiety. Coefficient omega estimates for the DASS-21 scale scores were good. Further investigations of the bifactor structure and psychometric properties of the DASS-21, specifically its incremental and discriminant validity, using known clinical groups are needed. © 2012 Wiley Periodicals, Inc.

  12. The Perceived Stress Reactivity Scale: Measurement Invariance, Stability, and Validity in Three Countries

    Science.gov (United States)

    Schlotz, Wolff; Yim, Ilona S.; Zoccola, Peggy M.; Jansen, Lars; Schulz, Peter

    2011-01-01

    There is accumulating evidence that individual differences in stress reactivity contribute to the risk for stress-related disease. However, the assessment of stress reactivity remains challenging, and there is a relative lack of questionnaires reliably assessing this construct. We here present the Perceived Stress Reactivity Scale (PSRS), a…

  13. Towards modeling intergranular stress corrosion cracks on grain size scales

    International Nuclear Information System (INIS)

    Simonovski, Igor; Cizelj, Leon

    2012-01-01

    Highlights: ► Simulating the onset and propagation of intergranular cracking. ► Model based on the as-measured geometry and crystallographic orientations. ► Feasibility, performance of the proposed computational approach demonstrated. - Abstract: Development of advanced models at the grain size scales has so far been mostly limited to simulated geometry structures such as for example 3D Voronoi tessellations. The difficulty came from a lack of non-destructive techniques for measuring the microstructures. In this work a novel grain-size scale approach for modelling intergranular stress corrosion cracking based on as-measured 3D grain structure of a 400 μm stainless steel wire is presented. Grain topologies and crystallographic orientations are obtained using a diffraction contrast tomography, reconstructed within a detailed finite element model and coupled with advanced constitutive models for grains and grain boundaries. The wire is composed of 362 grains and over 1600 grain boundaries. Grain boundary damage initialization and early development is then explored for a number of cases, ranging from isotropic elasticity up to crystal plasticity constitutive laws for the bulk grain material. In all cases the grain boundaries are modeled using the cohesive zone approach. The feasibility of the approach is explored.

  14. A literature review of the application of the Geriatric Depression Scale, Depression Anxiety Stress Scales and Post-traumatic Stress Disorder Checklist to community nursing cohorts.

    Science.gov (United States)

    Allen, Jacqui; Annells, Merilyn

    2009-04-01

    To explore through literature review the appropriateness of three common tools for use by community nurses to screen war veteran and war widow(er) clients for depression, anxiety and post-traumatic stress disorder. War veterans and, to a lesser extent, war widow(er)s, are prone to mental health challenges, especially depression, anxiety and post-traumatic stress disorder. Community nurses do not accurately identify such people with depression and related disorders although they are well positioned to do so. The use of valid and reliable self-report tools is one method of improving nurses' identification of people with actual or potential mental health difficulties for referral to a general practitioner or mental health practitioner for diagnostic assessment and treatment. The Geriatric Depression Scale, Depression Anxiety Stress Scales and Post-traumatic Stress Disorder Checklist are frequently recommended for mental health screening but the appropriateness of using the tools for screening war veteran and war widow(er) community nursing clients who are often aged and have functional impairment, is unknown. Systematic review. Current literature informs that the Geriatric Depression Scale accurately predicts a diagnosis of depression in community nursing cohorts. The three Depression Anxiety Stress Scales subscales of depression, anxiety and stress are valid; however, no studies were identified that compared the performance of the Depression Anxiety Stress Scales in predicting diagnoses of depression or anxiety. The Post-traumatic Stress Disorder Checklist predicts post-traumatic stress disorder in community cohorts although no studies meeting the selection criteria included male participants. This review provides recommendations for the use of the Geriatric Depression Scale, Depression Anxiety Stress Scales and The Post-traumatic Stress Disorder Checklist based on examination of the published evidence for the application of these screening tools in samples

  15. Teacher Stress Inventory: validation of the Greek version and perceived stress levels among 3,447 educators.

    Science.gov (United States)

    Kourmousi, Ntina; Darviri, Christina; Varvogli, Liza; Alexopoulos, Evangelos C

    2015-01-01

    The Teacher Stress Inventory (TSI) is an instrument for measuring occupational stress in teachers. This study aimed to translate and adapt it for use in Greece, and then assess its reliability and validity. The Greek versions of the TSI and the 14-item Perceived Stress Scale (PSS-14) were posted on all Greek educators' official sites during May 2012. A nationwide sample of 3,447 teachers of all levels and specialties completed the questionnaires via the Internet. Reliability was determined by the calculation of Cronbach's alpha coefficient. Confirmatory factor analysis was conducted and validity was further examined by investigating the correlation of the TSI with the PSS-14 and their association with demographics and work-related factors. Satisfactory Cronbach's alpha values (above 0.70) were found for all TSI dimensions. Confirmatory factor analysis confirmed the two-factor construct of TSI (root mean square error of approximation, comparative fit index, and goodness-of-fit index values were 0.079, 0.956, and 0.951, respectively), confirming the pre-established theory for the two latent variables, Stress Sources and Stress Manifestations. Significant correlations were found between TSI subscales, PSS-14 sex, age, lack of support, and students' difficulties. The Greek version of the TSI was found to have satisfactory psychometric properties, and its use for assessing stress in Greek teachers is warranted.

  16. Negative affect mediates effects of psychological stress on disordered eating in young Chinese women.

    Directory of Open Access Journals (Sweden)

    Jue Chen

    Full Text Available BACKGROUND: The bi-relationships between psychological stress, negative affect and disordered eating has been well studied in western culture, while tri-relationship among them, i.e. how some of those factors influence these bi-relationships, has rarely been studied. However, there has been little related study in the different Chinese culture. This study was conducted to investigate the bi-relationships and tri-relationship between psychological stress, negative affect, and disordered eating attitudes and behaviors in young Chinese women. METHODOLOGY: A total of 245 young Chinese policewomen employed to carry out health and safety checks at the 2010 Shanghai World Expo were recruited in this study. The Chinese version of the Perceived Stress Scale (PSS-10, Beck Depression Inventory Revised (BDI-II, Beck Anxiety Inventory (BAI, and Eating Attitude Test (EAT-26 were administered to all participants. PRINCIPAL FINDINGS: The total scores of PSS-10, BDI-II and BAI were all highly correlated with that of EAT-26. The PSS-10 score significantly correlated with both BDI-II and BAI scores. There was no statistically significant direct effect from perceived stress to disordered eating (-0.012, 95%CI: -.038~0.006, p=0.357, however, the indirect effects from PSS-10 via affect factors were statistically significant, e.g. the estimated mediation effects from PSS to EAT-26 via depression and anxiety were 0.036 (95%CI: 0.022~0.044, p<0.001 and 0.015 (95%CI: 0.005~0.023, p<0.01, respectively. CONCLUSIONS: Perceived stress and negative affects of depression and anxiety were demonstrated to be strongly associated with disordered eating. Negative affect mediated the relationship between perceived stress and disordered eating. The findings suggest that effective interventions and preventative programmes for disordered eating should pay more attention to depression and anxiety among the young Chinese female population.

  17. Pseudo-spark switch (PSS) characteristics under different operation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hamad, B. H., E-mail: dr.bassmahussain@gmail.com; Ahmad, A. K., E-mail: ahmad.kamal@sc.nahrainuniv.edu.iq [College of Science, Al Nahrain University, Jadria, Baghdad (Iraq); Lateef, K. H., E-mail: kamalhlatif@yahoo.com [Ministry of Science and Technology, Jadria, Baghdad (Iraq)

    2016-08-15

    The present paper concentrates on the characteristics of the pseudospark switch (PSS) designed in a previous work. The special characteristics of PSS make it a replacement for other high voltage switches such as thyratrons and ordinary high-pressure spark gaps. PSS is characterized by short rise time and small jitter time. The pseudo park chamber consists of two hollow cylindrical electrodes made of a stainless steel material (type 306L) separated by an insulator. The insulator used in our design is a glazed ceramic 70 mm in diameter and 3.5 mm in thickness. A PSS with an anode voltage of 29.2 kV, and a current of 3.6 kA and 11 ns rise time was achieved and used successfully at a repetition rate of about 2.2 kHz. A simple trigger circuit designed, built, and used effectively reaching more than 1.56 kV trigger pulse which is sufficient to ignite the argon gas inside the cathode to cause a breakdown. A non-inductive dummy load is designed to be a new technique to find the accurate value of the PSS inductance. A jitter time of ±10 ns pulses is observed to occur in a reliable manner for more than 6 h of continuous operation. In this research, the important parameters of this switch like rise time, peak current, and anode voltage were studied at various values of charging capacitance. The lifetime of this system is depending on the kind of the electrode material and on the type of insulation material in the main gap of the pseudospark switch.

  18. Buoyancy limits on magnetic viscosity stress-law scalings in quasi stellar object accretion disk models

    International Nuclear Information System (INIS)

    Sakimoto, P.J.

    1985-01-01

    Quasi-Stellar Objects (QSOs) are apparently the excessively bright nuclei of distant galaxies. They are thought to be powered by accretion disks surrounding supermassive black holes: however, proof of this presumption is hampered by major uncertainties in the viscous stress necessary for accretion to occur. Models generally assume an and hoc stress law which scales the stress with the total pressure. Near the black hole, radiation pressure dominates gas pressure; scaling the stress with the radiation pressure results in disk models that are thermally unstable and optically thin. This dissertation shows that a radiation pressure scaling for the stress is not possible if the viscosity is due to turbulent magnetic Maxwell stresses. The argument is one of internal self-consistency. First, four model accretion disks that bound the reasonably expected ranges of viscous stress scalings and vertical structures are constructed. Magnetic flux tubes of various initial field strengths are then placed within these models, nd their buoyancy is modeled numerically. In disks using the radiation pressure stress law scaling, low opacities allow rapid heat flow into the flux tubes: the tubes are extremely buoyant, and magnetic fields strong enough to provide the required stress cannot be retained. If an alternative gas pressure scaling for the stress is assumed, then the disks are optically thick; flux tubes have corresponding lower buoyancy, and magnetic fields strong enough to provide the stress can be retained for dynamically significant time periods

  19. Reliability and preliminary evidence of validity of a Farsi version of the depression anxiety stress scales.

    Science.gov (United States)

    Bayani, Ali Asghar

    2010-08-01

    The internal consistency, test-retest reliability, and construct validity of the Farsi version of the Depression Anxiety Stress Scales were examined, with a sample of 306 undergraduate students (123 men, 183 women) ranging from 18 to 51 years of age (M age = 25.4, SD = 6.1). Participants completed the Satisfaction with Life Scale, Rosenberg Self-esteem Scale, and the Depression Anxiety Stress Scales. The findings confirmed the preliminary reliabilities and preliminary construct validity of the Farsi translation of the Depression Anxiety Stress Scales.

  20. Subgrid-scale stresses and scalar fluxes constructed by the multi-scale turnover Lagrangian map

    Science.gov (United States)

    AL-Bairmani, Sukaina; Li, Yi; Rosales, Carlos; Xie, Zheng-tong

    2017-04-01

    The multi-scale turnover Lagrangian map (MTLM) [C. Rosales and C. Meneveau, "Anomalous scaling and intermittency in three-dimensional synthetic turbulence," Phys. Rev. E 78, 016313 (2008)] uses nested multi-scale Lagrangian advection of fluid particles to distort a Gaussian velocity field and, as a result, generate non-Gaussian synthetic velocity fields. Passive scalar fields can be generated with the procedure when the fluid particles carry a scalar property [C. Rosales, "Synthetic three-dimensional turbulent passive scalar fields via the minimal Lagrangian map," Phys. Fluids 23, 075106 (2011)]. The synthetic fields have been shown to possess highly realistic statistics characterizing small scale intermittency, geometrical structures, and vortex dynamics. In this paper, we present a study of the synthetic fields using the filtering approach. This approach, which has not been pursued so far, provides insights on the potential applications of the synthetic fields in large eddy simulations and subgrid-scale (SGS) modelling. The MTLM method is first generalized to model scalar fields produced by an imposed linear mean profile. We then calculate the subgrid-scale stress, SGS scalar flux, SGS scalar variance, as well as related quantities from the synthetic fields. Comparison with direct numerical simulations (DNSs) shows that the synthetic fields reproduce the probability distributions of the SGS energy and scalar dissipation rather well. Related geometrical statistics also display close agreement with DNS results. The synthetic fields slightly under-estimate the mean SGS energy dissipation and slightly over-predict the mean SGS scalar variance dissipation. In general, the synthetic fields tend to slightly under-estimate the probability of large fluctuations for most quantities we have examined. Small scale anisotropy in the scalar field originated from the imposed mean gradient is captured. The sensitivity of the synthetic fields on the input spectra is assessed by

  1. Teaching PSS in business practice : A win-win-win approach

    NARCIS (Netherlands)

    Keskin, D.; Brezet, J.C.; Diehl, J.C.

    2010-01-01

    This paper presents the findings gained through the implementation of the renewed Product Service Systems (PSS) course within the Design for Sustainability curriculum in 2010. Based upon the outcomes of our recent PSS research projects in practice and evaluation of the earlier PSS courses a new

  2. Perceived stress and reported cognitive symptoms among Georgia patients with systemic lupus erythematosus.

    Science.gov (United States)

    Plantinga, L; Lim, S S; Bowling, C B; Drenkard, C

    2017-09-01

    Objective To examine associations of perceived stress with cognitive symptoms among adults with systemic lupus erythematosus (SLE). Methods Among 777 adult (≥18 years) SLE patients, the association of Perceived Stress Scale (PSS) scores with two self-reported cognitive symptoms was examined: forgetfulness (severe/moderate vs. mild/none; from the Systemic Lupus Activity Questionnaire) and difficulty concentrating (all/most vs. some/little/none of the time; from the Lupus Impact Tracker). The study used multivariable logistic regression to estimate the odds ratios (ORs) per minimal important difference (MID = 0.5*SD) of PSS score and cognitive symptoms. Results Forgetfulness and difficulty concentrating were reported by 41.7% and 29.5%, respectively. Women and those with less education and high disease activity had higher PSS scores and were more likely to report cognitive symptoms than their counterparts. With adjustment for age, race, sex, education, and disease activity, each MID increase in PSS score was associated with higher prevalence of forgetfulness (OR = 1.43, 95% CI 1.29-1.47) and difficulty concentrating (OR = 2.19, 95% CI 1.90-2.52). No substantial differences in this association by age, race, sex, or disease activity were noted. Conclusions SLE patients, particularly those with high disease activity, report a high burden of cognitive symptoms, for which stress may be a modifiable risk factor.

  3. Hair cortisol levels, perceived stress and body mass index in women and children living in socioeconomically disadvantaged neighborhoods: the READI study.

    Science.gov (United States)

    Olstad, Dana Lee; Ball, Kylie; Wright, Craig; Abbott, Gavin; Brown, Erin; Turner, Anne Isabella

    2016-01-01

    Disadvantaged communities provide adverse psychosocial exposures that have been linked to high levels of stress, and this may provide one explanatory pathway linking socioeconomic disadvantage to obesity. This study used hair cortisol analysis to quantify associations between stress and body mass index (BMI), and between hair cortisol and perceived psychological stress levels, in women and children living in socioeconomically disadvantaged neighborhoods. Participants were a volunteer sample of 70 women from the Resilience for Eating and Activity Despite Inequality study, including 30 maternal-child pairs. Women self-reported body weight, height and perceived psychological stress using the Perceived Stress Scale (PSS), and provided hair samples for themselves and their child. Children's body weight and height were measured. Following extraction, hair cortisol levels were measured using enzyme-linked immunosorbent assay. Multiple linear regression models examined associations between stress and BMI, and between hair cortisol and perceived stress levels in women and children. Women's hair cortisol levels were not associated with their BMI or PSS scores. Women's PSS scores were positively associated with their BMI (p = 0.015). Within maternal-child pairs, mothers and children's hair cortisol levels were strongly positively associated (p = 0.006). Maternal hair cortisol levels and PSS scores were unrelated to their child's zBMI. Children's hair cortisol levels were not associated with their zBMI or with their mother's PSS score. Findings suggest that cortisol-based and perceived psychological measures of stress may be distinct among women and children living in disadvantaged neighborhoods. Perceived psychological measures may be more important predictors of weight-related risk.

  4. Examining perceptions of academic stress and its sources among university students: The Perception of Academic Stress Scale

    Directory of Open Access Journals (Sweden)

    Dalia Bedewy

    2015-07-01

    Full Text Available The development of a scale to measure perceived sources of academic stress among university students. Based on empirical evidence and recent literature review, we developed an 18-item scale to measure perceptions of academic stress and its sources. Experts ( n  = 12 participated in the content validation process of the instrument before it was administered to ( n  = 100 students. The developed instrument has internal consistency reliability of 0.7 (Cronbach’s alpha, there was evidence for content validity, and factor analysis resulted in four correlated and theoretically meaningful factors. We developed and tested a scale to measure academic stress and its sources. This scale takes 5 minutes to complete.

  5. COMT Diplotype Amplifies Effect of Stress on Risk of Temporomandibular Pain.

    Science.gov (United States)

    Slade, G D; Sanders, A E; Ohrbach, R; Bair, E; Maixner, W; Greenspan, J D; Fillingim, R B; Smith, S; Diatchenko, L

    2015-09-01

    When measured once, psychological stress predicts development of painful temporomandibular disorder (TMD). However, a single measurement fails to characterize the dynamic nature of stress over time. Moreover, effects of stress on pain likely vary according to biological susceptibility. We hypothesized that temporal escalation in stress exacerbates risk for TMD, and the effect is amplified by allelic variants in a gene, catechol-O-methyltransferase (COMT), regulating catechol neurotransmitter catabolism. We used data from the Orofacial Pain: Prospective Evaluation and Risk Assessment prospective cohort study of 2,707 community-dwelling adults with no lifetime history of TMD on enrollment. At baseline and quarterly periods thereafter, the Perceived Stress Scale (PSS) measured psychological stress. Genotyped DNA from blood samples determined COMT diplotypes. During follow-up of 0.25 to 5.2 y, 248 adults developed examiner-verified incident TMD. PSS scores at baseline were 20% greater (P stress escalation was limited to incident cases with COMT diplotypes coding for low-activity COMT, signifying impaired catabolism of catecholamines. Cox regression models confirmed significant effects on TMD hazard of both baseline PSS (P stress showed that a postbaseline increase of 1.0 standard deviation in PSS more than doubled risk of TMD incidence in subjects with low-activity COMT diplotypes (hazard ratio = 2.35; 95% confidence limits: 1.66, 3.32), an effect not found in subjects with high-activity COMT diplotypes (hazard ratio = 1.42; 95% confidence limits: 0.96, 2.09). Findings provide novel insights into dynamic effects of psychological stress on TMD pain, highlighting that effects are most pronounced in individuals whose genetic susceptibility increases responsiveness to catecholamine neurotransmitters. © International & American Associations for Dental Research 2015.

  6. A Framework for PSS Business Models: Formalization and Application

    OpenAIRE

    Adrodegari, Federico; Saccani, Nicola; Kowalkowski, Christian

    2016-01-01

    In order to successfully move "from products to solutions", companies need to redesign their business model. Nevertheless, service oriented BMs in product-centric firms are under-investigated in the literature: very few works develop a scheme of analysis of such BMs. To provide a first step into closing this gap, we propose a new framework to describe service-oriented BMs, pointing out the main BM components and related PSS characteristics. Thus, the proposed framework aims to help companies ...

  7. Web-Based and Mobile Stress Management Intervention for Employees

    DEFF Research Database (Denmark)

    Heber, E.; Lehr, D.; Ebert, D. D.

    2016-01-01

    Background: Work-related stress is highly prevalent among employees and is associated with adverse mental health consequences. Web-based interventions offer the opportunity to deliver effective solutions on a large scale; however, the evidence is limited and the results conflicting. Objective......: This randomized controlled trial evaluated the efficacy of guided Web-and mobile-based stress management training for employees. Methods: A total of 264 employees with elevated symptoms of stress (Perceived Stress Scale-10, PSS-10 >= 22) were recruited from the general working population and randomly assigned...... to an Internet-based stress management intervention (iSMI) or waitlist control group. The intervention (GET. ON Stress) was based on Lazarus's transactional model of stress, consisted of seven sessions, and applied both well-established problem solving and more recently developed emotion regulation strategies...

  8. Avidin/PSS membrane microcapsules with biotin-binding activity.

    Science.gov (United States)

    Endo, Yoshihiro; Sato, Katsuhiko; Sugimoto, Kentaro; Anzai, Jun-ichi

    2011-08-15

    Polyelectrolyte microcapsules with avidin-poly(styrene sulfonate) (PSS) membrane were prepared by a layer-by-layer deposition technique. The uptake and release of biotin-labeled fluorescein (b-FITC) as well as immobilization of biotin-labeled glucose oxidase (b-GOx) to the microcapsule were studied. The polyelectrolyte microcapsules were prepared by coating the surface of calcium carbonate (CaCO(3)) microparticles with an avidin/PSS multilayer membrane, followed by dissolution of CaCO(3) core in an ethylenediaminetetraacetic acid solution. Inner and outer poly(allylamine)/PSS films were required to isolate the microcapsules, whereas microcapsules could not be formed without the support. The uptake of b-FITC into the microcapsule was highly enhanced through a strong binding of b-FITC to avidin as compared with the uptake of biotin-free FITC. Release of b-FITC from the microcapsule was accelerated upon addition of biotin due to a competitive binding of the added biotin to the binding site of avidin. Similarly, the surface of microcapsule was modified with b-GOx with retaining its catalytic activity. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Psychometric Validation of Stress and Compliance Scale for ...

    African Journals Online (AJOL)

    Purpose: To provide factorial analytical findings, and to construct validation and normative .... participants were asked to fold the questionnaire ... both cross loaded onto both factors. .... Compas B, Grant K. Ey S. Psychosocial stress and child.

  10. Negative affect mediates effects of psychological stress on disordered eating in young Chinese women.

    Science.gov (United States)

    Chen, Jue; Wang, Zhen; Guo, Boliang; Arcelus, Jon; Zhang, Haiyin; Jia, Xiuzhen; Xu, Yong; Qiu, Jianyin; Xiao, Zeping; Yang, Min

    2012-01-01

    The bi-relationships between psychological stress, negative affect and disordered eating has been well studied in western culture, while tri-relationship among them, i.e. how some of those factors influence these bi-relationships, has rarely been studied. However, there has been little related study in the different Chinese culture. This study was conducted to investigate the bi-relationships and tri-relationship between psychological stress, negative affect, and disordered eating attitudes and behaviors in young Chinese women. A total of 245 young Chinese policewomen employed to carry out health and safety checks at the 2010 Shanghai World Expo were recruited in this study. The Chinese version of the Perceived Stress Scale (PSS-10), Beck Depression Inventory Revised (BDI-II), Beck Anxiety Inventory (BAI), and Eating Attitude Test (EAT-26) were administered to all participants. The total scores of PSS-10, BDI-II and BAI were all highly correlated with that of EAT-26. The PSS-10 score significantly correlated with both BDI-II and BAI scores. There was no statistically significant direct effect from perceived stress to disordered eating (-0.012, 95%CI: -.038~0.006, p=0.357), however, the indirect effects from PSS-10 via affect factors were statistically significant, e.g. the estimated mediation effects from PSS to EAT-26 via depression and anxiety were 0.036 (95%CI: 0.022~0.044, peffective interventions and preventative programmes for disordered eating should pay more attention to depression and anxiety among the young Chinese female population.

  11. Gender Effect According to Item Directionality on the Perceived Stress Scale for Adults with Multiple Sclerosis

    Science.gov (United States)

    Gitchel, W. Dent; Roessler, Richard T.; Turner, Ronna C.

    2011-01-01

    Assessment is critical to rehabilitation practice and research, and self-reports are a commonly used form of assessment. This study examines a gender effect according to item wording on the "Perceived Stress Scale" for adults with multiple sclerosis. Past studies have demonstrated two-factor solutions on this scale and other scales measuring…

  12. Perceived stress, reproductive hormones, and ovulatory function: a prospective cohort study

    Science.gov (United States)

    Schliep, Karen C.; Mumford, Sunni L.; Vladutiu, Catherine J.; Ahrens, Katherine A.; Perkins, Neil J.; Sjaarda, Lindsey A.; Kissell, Kerri A.; Prasad, Ankita; Wactawski-Wende, Jean; Schisterman, Enrique F.

    2014-01-01

    Background Stress has been shown to suppress ovulation in experimental models, but its effect on human reproduction at the population level is unclear. Methods Healthy women (n=259), aged 18–44 years from Western New York, were followed for two menstrual cycles (2005–2007). Women completed daily perceived stress assessments, a 4-item Perceived Stress Scale (PSS-4) up to four times each cycle, and a 14-item PSS at baseline. Mixed model analyses were used to assess effects of stress on log reproductive hormone concentrations and sporadic anovulation. Results High versus low daily stress was associated with lower estradiol (-9.5%; 95% confidence interval (CI)= -15.6% to -3.0%), free estradiol (-10.4% [-16.5% to -3.9%]), and LH (-14.8% = [-21.3% to -7.7%]), and higher FSH (6.2% [2.0% to 10.5%]) after adjusting for age, race, percent body fat, depression score, and time-varying hormones and vigorous exercise. High versus low daily stress was also associated with lower luteal progesterone (-10.4% [-19.7% to -0.10%]) and higher odds of anovulation (adjusted OR = 2.2 [95% CI=1.0 to 4.7]). For each unit increase in daily stress level, women had a 70% higher odds of an anovulatory episode (OR=1.7 [1.1 to 2.4]). Similar but attenuated results were found for the association between the PSS-4 and reproductive hormones, while null findings were found for the baseline PSS. Conclusion Daily perceived stress does appear to interfere with menstrual cycle function among women with no known reproductive disorders, warranting further research to explore potential population-level impacts and causal biologic mechanisms. PMID:25643098

  13. The Danish Prostatic Symptom Score (DAN-PSS-1) questionnaire is reliable in stroke patients

    DEFF Research Database (Denmark)

    Tibaek, Sigrid; Jensen, Rigmor; Klarskov, Peter

    2006-01-01

    . The questionnaire consists of 12 questions related to lower urinary tract symptoms (LUTS). The participants were asked to state the frequency and severity of their symptoms (symptom score) and its impact on their daily life (bother score). Seventy-one stroke patients were included and 59 (83%) answered...... the questionnaire twice. The reliability test was done in two aspects: (a) detecting the frequency of each symptom and its bother factor, the scores were reduced to a two-category scale (=0, >0) and simple kappa statistics was used; (b) detecting the severity of each symptom and its bother factor, the total scale...... (kappa(w) = 0.48) to good (kappa(w) = 0.68). CONCLUSIONS: The DAN-PSS-1 questionnaire had acceptable test-retest reliability and may be suitable for measuring the frequency and severity of LUTS and its bother factor in stroke patients....

  14. Stress levels and depressive symptoms in NICU mothers in the early postpartum period.

    Science.gov (United States)

    Alkozei, Anna; McMahon, Erin; Lahav, Amir

    2014-11-01

    This study examined whether particular maternal and infant factors can identify mothers at risk for increased stress upon admission to the neonatal intensive care unit (NICU). Eighty-five mothers of preterm infants (25-34 weeks gestation) were assessed using the Parental Stressor Scale (PSS:NICU) and the Edinburgh Postnatal Depression Scale (EPDS) within 3.24 ± 1.58 d postpartum. Hierarchical linear regression models were used to determine the extent to which maternal stress is influenced by individual factors. Fifty-two percent of mothers experienced increased stress (PSS:NICU score ≥3) and 38% had significant depressive symptoms (EPDS score ≥10). Stress related to alterations in parental role was the most significant source of stress among NICU mothers. Distance from the hospital and married marital status were significant predictors for stress related to alterations in parental role (p = 0.003) and NICU sights and sounds (p = 0.01), respectively. Higher stress levels were associated with higher depressive scores (p = 0.001). Maternal mental health factors, demographic factors, pregnancy factors and infant characteristics were not associated with increased stress. Elevated stress levels and depressive symptoms are already present in mothers of preterm infants upon NICU admission. Being married or living long distance from the hospital is associated with higher stress. Future work is needed to develop effective interventions for alleviating stress in NICU mothers and preventing its potential development into postnatal depression.

  15. Perceived stress, psychological well-being and burnout among female nurses working in government hospitals

    OpenAIRE

    Divinakumar K J; Shivram Bhat Pookala; Ram Chandra Das

    2014-01-01

    Background: Few studies have studied about the Burnout among government employed Female Nurses in India. Methods: A cross sectional survey was done by mailing questionnaires containing Perceived Stress Scale (PSS-10), Copenhagen Burnout Inventory (CBI) and General Health Questionnaire (GHQ-28) to all 603 Nurses posted in thirty government hospitals of central India. Fifty seven percent responded and 298 valid questionnaires were analysed. Results: Sixty three nurses (21%) had GHQ 28 sc...

  16. Machine-Washable PEDOT:PSS Dyed Silk Yarns for Electronic Textiles.

    Science.gov (United States)

    Ryan, Jason D; Mengistie, Desalegn Alemu; Gabrielsson, Roger; Lund, Anja; Müller, Christian

    2017-03-15

    Durable, electrically conducting yarns are a critical component of electronic textiles (e-textiles). Here, such yarns with exceptional wear and wash resistance are realized through dyeing silk from the silkworm Bombyx mori with the conjugated polymer:polyelectrolyte complex PEDOT:PSS. A high Young's modulus of approximately 2 GPa combined with a robust and scalable dyeing process results in up to 40 m long yarns that maintain their bulk electrical conductivity of approximately 14 S cm -1 when experiencing repeated bending stress as well as mechanical wear during sewing. Moreover, a high degree of ambient stability is paired with the ability to withstand both machine washing and dry cleaning. For the potential use for e-textile applications to be illustrated, an in-plane thermoelectric module that comprises 26 p-type legs is demonstrated by embroidery of dyed silk yarns onto a piece of felted wool fabric.

  17. Caracterização de hidrogéis condutores constituídos por PAAm e PEDOT/PSS por meio de planejamento fatorial Characterization of conducting hydrogels made with PAAm and PEDOT/PSS using factorial design

    Directory of Open Access Journals (Sweden)

    Fauze A. Aouada

    2008-06-01

    , maximum compression stress, ionic conductance and relative intensity of light transmitted through the hydrogel. ANOVA was obtained using Statistical Software®. The results of the twelve runs from the factorial design (eight runs from 2³ plus four central point replicates were applied to evaluate the main effects and their interaction, in addition to decide if they are statistically significant. The results demonstrated that mechanical stability of semi-IPN hydrogels is preserved, with PEDOT/PSS creating additional entanglements within the PAAm network. In addition, the optical properties are strongly influenced by the presence of PEDOT/PSS. In summary, hydrogels could be synthesized with controlled hydrophilicity, transparency and mechanical stability, which is important for optical devices.

  18. Perceived Stress After Acute Myocardial Infarction: A Comparison Between Young and Middle-Aged Women Versus Men.

    Science.gov (United States)

    Xu, Xiao; Bao, Haikun; Strait, Kelly M; Edmondson, Donald E; Davidson, Karina W; Beltrame, John F; Bueno, Héctor; Lin, Haiqun; Dreyer, Rachel P; Brush, John E; Spertus, John A; Lichtman, Judith H; DʼOnofrio, Gail; Krumholz, Harlan M

    2017-01-01

    The aim of the study was to examine how psychological stress changes over time in young and middle-aged patients after experiencing an acute myocardial infarction (AMI) and whether these changes differ between men and women. We analyzed data obtained from 2358 women and 1151 men aged 18 to 55 years hospitalized for AMI. Psychological stress was measured using the 14-item Perceived Stress Scale (PSS-14) at initial hospitalization and at 1 month and 12 months after AMI. We used linear mixed-effects models to examine changes in PSS-14 scores over time and sex differences in these changes, while adjusting for patient characteristics and accounting for correlation among repeated observations within patients. Overall, patients' perceived stress decreased over time, especially during the first month after AMI. Women had higher levels of perceived stress than men throughout the 12-month period (difference in PSS-14 score = 3.63, 95% confidence interval = 3.08 to 4.18, p men = 1.74, 95% confidence interval = 1.32 to 2.16, p middle-aged patients with AMI, women reported higher levels of perceived stress than men throughout the first 12 months of recovery. However, women and men had a similar pattern in how perceived stress changed over time.

  19. Stress determination in thermally grown alumina scales using ruby luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Renusch, D.; Veal, B.W.; Koshelev, I.; Natesan, K.; Grimsditch [Argonne National Lab., IL (United States); Hou, P.Y. [Lawrence Berkeley Lab., CA (United States)

    1996-06-01

    By exploiting the strain dependence of the ruby luminescence line, we have measured the strain in alumina scales thermally grown on Fe-Cr- Al alloys. Results are compared and found to be reasonably consistent with strains determined using x rays. Oxidation studies were carried out on alloys Fe - 5Cr - 28Al and Fe - 18Cr - 10Al (at.%). Significantly different levels of strain buildup were observed in scales on these alloys. Results on similar alloys containing a ``reactive element`` (Zr or Hf) in dilute quantity are also presented. Scales on alloys containing a reactive element (RE) can support significantly higher strains than scales on RE-free alloys. With the luminescence technique, strain relief associated with spallation thresholds is readily observed.

  20. Relationship among perceived stress, anxiety, depression and craniocervical pain in nursing professionals under stress at work

    Directory of Open Access Journals (Sweden)

    Daniela Pozzebon

    Full Text Available Abstract Introduction: The appearance and evolution of some clinical pain conditions may be influenced by stress and other psychosocial factors. Face, head and cervical muscles may increase their activity and tension in the presence of stress, leading to craniocervicomandibular pain in individuals exposed to stress. Objective: To assess the relationship among perceived stress, anxiety, depression and craniocervicomandibular pain in nursing professionals under stress at work. Materials and Methods: Forty-three women under stress at work, according to the Job Stress Scale (JSS, were assessed by the Perceived Stress Scale (PSS, the Hospital Anxiety and Depression Scale (HADS, pressure pain threshold, measured by algometry, and muscle sensitivity to hand palpation of the masticatory and cervical muscles. Results: A low moderate level of perceived stress was found in 62.79% of the sample, anxiety in 11.63% and depression in 9.30%. The psychosocial scales correlated with each other. No correlation was found between pressure pain threshold and perceived stress, anxiety and depression. The level of pain to hand palpation correlated with the perceived stress scores. Conclusion: Pressure pain threshold was not influenced by the psychosocial factors assessed. Pain intensity to hand palpation, however, was higher as the perception of stress increased.

  1. Adaptation to Portuguese of the Depression, Anxiety and Stress Scales (DASS)

    OpenAIRE

    Apóstolo,João Luís Alves; Mendes,Aida Cruz; Azeredo,Zaida Aguiar

    2006-01-01

    Objective: to adapt to Portuguese, of Portugal, the Depression, Anxiety and Stress Scales, a 21-item short scale (DASS 21), designed to measure depression, anxiety and stress. Method: After translation and back-translation with the help of experts, the DASS 21 was administered to patients in external psychiatry consults (N=101), and its internal consistency, construct validity and concurrent validity were measured. Results: The DASS 21 properties certify its quality to measure emotional state...

  2. Factor Structure of the Acute Stress Disorder Scale in a Sample of Hurricane Katrina Evacuees

    Science.gov (United States)

    Edmondson, Donald; Mills, Mary Alice; Park, Crystal L.

    2010-01-01

    Acute stress disorder (ASD) is a poorly understood and controversial diagnosis (A. G. Harvey & R. A. Bryant, 2002). The present study used confirmatory factor analysis (CFA) to test the factor structure of the most widely used self-report measure of ASD, the Acute Stress Disorder Scale (R. A. Bryant, M. L. Moulds, & R. M. Guthrie, 2000),…

  3. Experimental determination and theoretical analysis of local residual stress at grain scale

    NARCIS (Netherlands)

    Basu, Indranil; Ocelík, Václav; De Hosson, Jeff Th M.

    2017-01-01

    Grain/phase boundaries contribute significantly to build up of residual stresses, owing to varied plastic/thermal response of different grain orientations or phases during thermomechanical treatment. Hence, accurate quantification of such local scale stress gradients in commercial components is

  4. Direct laser interference patterning of poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT-PSS) thin films

    International Nuclear Information System (INIS)

    Lasagni, Andres F.; Hendricks, Jeffrey L.; Shaw, Charles M.; Yuan, Dajun; Martin, David C.; Das, Suman

    2009-01-01

    We have developed a patterning procedure based on selective ablation using interference patterns with ns-laser pulses to fabricate periodic arrays on large areas of poly(3,4-ethylene dioxythiophene)-poly(4-styrene sulfonic acid) (PEDOT-PSS) thin films over a metallic gold-palladium layer. Single pulse laser-ablation experiments were performed to study the ablation characteristics of the thin films as a function of the film thickness. The ablation threshold fluence of the PEDOT-PSS films was found to be dependent on thickness with values ranging from 43 mJ/cm 2 to 252 mJ/cm 2 . Additionally, fluences at which the PEDOT-PSS films could be ablated without inducing damage in the underlying metallic films were observed (128 mJ/cm 2 and 402 mJ/cm 2 for film thicknesses of 70 nm and 825 nm, respectively). Linear periodic arrays with line spacings of 7.82 μm and 13.50 μm were also fabricated. The surface topography of these arrays was analyzed using scanning electron and atomic force microscopy. For thicker polymeric layers, several peeled sub-layers of the conjugated polymer with average thicknesses of about 165-185 nm were observed in the ablation experiments. The size and scale of structures produced by this technique could be suitable for several biomedical applications and devices in which controlling cell adhesion, promoting cell alignment, or improving biocompatibility are important.

  5. Size-scaling of tensile failure stress in boron carbide

    Energy Technology Data Exchange (ETDEWEB)

    Wereszczak, Andrew A [ORNL; Kirkland, Timothy Philip [ORNL; Strong, Kevin T [ORNL; Jadaan, Osama M. [University of Wisconsin, Platteville; Thompson, G. A. [U.S. Army Dental and Trauma Research Detachment, Greak Lakes

    2010-01-01

    Weibull strength-size-scaling in a rotary-ground, hot-pressed boron carbide is described when strength test coupons sampled effective areas from the very small (~ 0.001 square millimeters) to the very large (~ 40,000 square millimeters). Equibiaxial flexure and Hertzian testing were used for the strength testing. Characteristic strengths for several different specimen geometries are analyzed as a function of effective area. Characteristic strength was found to substantially increase with decreased effective area, and exhibited a bilinear relationship. Machining damage limited strength as measured with equibiaxial flexure testing for effective areas greater than ~ 1 mm2 and microstructural-scale flaws limited strength for effective areas less than 0.1 mm2 for the Hertzian testing. The selections of a ceramic strength to account for ballistically-induced tile deflection and to account for expanding cavity modeling are considered in context with the measured strength-size-scaling.

  6. Evaluation of a Web-Based Holistic Stress Reduction Pilot Program Among Nurse-Midwives.

    Science.gov (United States)

    Wright, Erin M

    2018-06-01

    Work-related stress among midwives results in secondary traumatic stress, posttraumatic stress disorder, and job attrition. The purpose of this pilot project was to evaluate the effectiveness of a holistic, web-based program using holistic modalities for stress reduction and improved coping among certified nurse-midwives. A convenience sample of 10 midwives participated in a web-based holistic stress reduction intervention using yoga, mindfulness-based stress reduction, and meditation for four days each week over 4 weeks. Participants completed pre- and postintervention questionnaires (Perceived Stress Scale [PSS] and the Coping Self-Efficacy Scale [CSES]) for evaluation of effectiveness. The PSS means showed improvement in midwives' stress (16.4-12.3). The CSES means showed improvement in coping (174.8-214.5). Improvement was shown in each subscale of the CSES ("uses problem-focused coping": 19.2%; "stops unpleasant thoughts and emotions": 20.3%; and "gets support from family and friends": 16.6%). Findings suggest the potential for stress reduction and improved coping skills after using holistic techniques in a web-based format within a cohort of nurse-midwives. Further research of web-based, holistic intervention for stress reduction among midwives is warranted.

  7. Reflections on product/service-system (PSS) conceptualisation in a course setting

    DEFF Research Database (Denmark)

    Tan, Adrian; McAloone, Timothy Charles; Lauridsen, Erik Hagelskjær

    2009-01-01

    Product/service-system (PSS) approaches have over the past decade received considerable attention as possible sustainable innovation strategies. This paper presents and reflects upon the background, rationale and experiences behind a PSS design methodology applied with engineering students...... in a project course for the past five years. The methodology proposes four complementary dimensions of PSS: value proposition, product life cycle, activity modelling cycle and actor network, that all seem to comprehensively describe the essential conceptual design perspectives. Each of these dimensions...

  8. The effect of emotional freedom technique on stress and anxiety in nursing students: A pilot study.

    Science.gov (United States)

    Patterson, Susan Librizzi

    2016-05-01

    Stress and anxiety have been identified as significant issues experienced by student nurses during their education. Some studies have suggested that the stress experienced by nursing students is greater than that experienced by medical students, other non-nursing healthcare students, degreed nurses, and the female population in general. A recently introduced energy type therapy, emotional freedom technique (EFT), has shown some success in reducing symptoms of anxiety, stress, and fear in a variety of settings. The purpose of this study was to determine the efficacy of EFT in decreasing anxiety and stress as a potential intervention to assist students in stress management. The study used a mixed method design of both qualitative and quantitative measures. Quantitatively, in a one group pretest-posttest design, participants received group instruction in the technique and were encouraged to repeat it daily. Self-reported anxiety was measured at baseline, and then weekly for four weeks using the Perceived Stress Scale (PSS) and the State-Trait Anxiety Inventory (STAI). The qualitative survey was completed by participants at the end of the study in order to capture a more subjective experience. The pilot study was conducted in a two-year college in the southeastern region of the United States. All enrolled nursing students in an associate degree nursing program were invited to participate. Participation was voluntary, resulting in an original convenience sample of thirty-nine nursing students (N=39). Data collection instruments included a demographic questionnaire, pretest State-Trait Anxiety Inventory (STAI) and Perceived Stress Scale (PSS). A qualitative questionnaire was also administered at the end of the four weeks. STAI and PSS were administered weekly. Data analysis using RMANOVA was performed at the second, third and the fourth week. Decreases in anxiety as measured on both the STAI and PSS were statistically significant (p=.05). For PSS, STAI state and trait

  9. Multiple congenital PSS in a dog: case report and literature review.

    Science.gov (United States)

    Leeman, Jessica J; Kim, Stanley E; Reese, David J; Risselada, Marije; Ellison, Gary W

    2013-01-01

    A 4 yr old spayed female mixed-breed dog presented with a 2 yr history of recurring increases in liver enzymes. Two congenital portosystemic shunts (PSSs) were identified using computed tomography (CT) angiography, which included a portoazygous and portorenal extrahepatic shunt. Double right renal veins were also identified. The shunts were successfully identified and attenuated with cellophane banding. Multiple congenital PSS is a rare phenomenon, but should be considered during exploratory laparotomy for PSS and in dogs with poor response to surgical attenuation of a single PSS. CT proved to be a crucial part of accurate diagnosis and surgical planning for this dog with multiple congenital PSS.

  10. How to Distinguish Patients with pSS among Individuals with Dryness without Invasive Diagnostic Studies

    Directory of Open Access Journals (Sweden)

    Agata Sebastian

    2018-01-01

    Full Text Available In the course of pSS, inflammatory cell infiltration consists mainly of lymphocytes infiltrating exocrine glands, which leads to their impaired function. The characteristic feature is generalized dryness. The aim of this study was to attempt to answer the question whether it is possible to distinguish between patients with pSS and individuals with dryness caused by other pathologies without applying invasive studies. The study included 68 patients with pSS and 43 healthy controls with dryness. FS ≥ 1 was observed in 90% of patients with pSS (with or without dryness, and only in 23% of the control group (only with xerostomia. In the pSS group, anaemia (p=0.0085, lymphocytopenia (p=0.0006, elevated ERS (p=0.001, higher RF titer, and ANA antibodies were noted. Configuration of anti-SSA + SSB + Ro52 antibodies was characteristic for the pSS group. Considering the clinical symptoms, statistically significant differences were noted between pSS patients and the control group in frequency (p=0.02 and severity (p=0.042 of fatigue, lymphadenopathy, major salivary gland involvement, and photosensitivity to UV light. In conclusion, invasive methods are pivotal in pSS diagnosis in this salivary gland biopsy. Chronic fatigue syndrome is more common in pSS patients and can be subjective distinguishing factor in the group of people with dryness.

  11. The Depression Anxiety and Stress Scale (DASS): The Study of Validity and Reliability

    Science.gov (United States)

    Akin, Ahmet; Cetin, Bayram

    2007-01-01

    This study investigated the validity and reliability of the Turkish version of the Depression Anxiety Stress Scale (DASS). The sample of the study consisted of 590 university students, 121 English teachers and 136 emotionally disturbed individuals who sought treatment in various clinics and counseling centers. Factor loadings of the scale ranged…

  12. Stress- and temperature-dependent scaling behavior of dynamic hysteresis in soft PZT bulk ceramics

    International Nuclear Information System (INIS)

    Yimnirun, R; Wongsaenmai, S; Wongmaneerung, R; Wongdamnern, N; Ngamjarurojana, A; Ananta, S; Laosiritaworn, Y

    2007-01-01

    Effects of electric field-frequency, electric field-amplitude, mechanical stress, and temperature on the hysteresis area, especially the scaling form, were investigated in soft lead zirconate titanate (PZT) bulk ceramics. The hysteresis area was found to depend on the frequency and field-amplitude with the same set of exponents as the power-law scaling for both with and without stresses. The inclusion of stresses into the power-law was obtained in the form of σ=0 > ∝ f -0.25 E 0 σ 0.45 which indicates the difference in energy dissipation between the under-stress and stress-free conditions. The power-law temperature scaling relations were obtained for hysteresis area (A) and remanent polarization P r , while the coercivity E C was found to scale linearly with temperature T. The three temperature scaling relations were also field-dependent. At fixed field amplitude E 0 , the scaling relations take the forms of ∝ T -1.1024 , P r ∼T -1.2322 and (E C0 - E C ) ∼T

  13. Stress and coping in parents of children with Prader-Willi syndrome: Assessment of the impact of a structured plan of care.

    Science.gov (United States)

    Tvrdik, Tatiana; Mason, Debbie; Dent, Karin M; Thornton, Lisa; Hornton, Sidney N; Viskochil, David H; Stevenson, David A

    2015-05-01

    Hyperphagia, developmental delays, and maladaptive behaviors are common in Prader-Willi syndrome (PWS) likely resulting in heightened parental stress. Objectives were to evaluate stress, describe usefulness of coping behaviors, and assess the impact of a structured Plan of Care (PC) on parents with children with PWS. Parents answered Perceived Stress Scale (PSS-14), Coping Health Inventory for Parents (CHIP), and narrative/demographic surveys. The PC was introduced to a cohort of parents after completion of the PSS-14 and CHIP and re-administered 4-6 month after the introduction of the PC. Higher parental stress (n = 57) was observed compared to the general population, and associated with parent's age, number of children living at home, and child's age and residential setting. "Maintaining family integration, cooperation, and an optimistic definition of the situation" was the most useful coping pattern. Thirty-eight parents answered the PSS-14 and CHIP after the PC. Parental stress decreased after the PC (P = 0.035). Coping behaviors related to "maintaining family integration" increased after the PC (P = 0.042). Women and men preferred different coping patterns before and after the PC. In conclusion, parental stress is increased in PWS, and a PC decreased stress and increased coping behaviors related to family stability for parents with children with PWS. © 2015 Wiley Periodicals, Inc.

  14. Reducing Stress Among Mothers in Drug Treatment: A Description of a Mindfulness Based Parenting Intervention.

    Science.gov (United States)

    Short, Vanessa L; Gannon, Meghan; Weingarten, Wendy; Kaltenbach, Karol; LaNoue, Marianna; Abatemarco, Diane J

    2017-06-01

    Background Parenting women with substance use disorder could potentially benefit from interventions designed to decrease stress and improve overall psychosocial health. In this study we assessed whether a mindfulness based parenting (MBP) intervention could be successful in decreasing general and parenting stress in a population of women who are in treatment for substance use disorder and who have infants or young children. Methods MBP participants (N = 59) attended a two-hour session once a week for 12 weeks. Within-group differences on stress outcome measures administered prior to the beginning of the MBP intervention and following the intervention period were investigated using mixed-effects linear regression models accounting for correlations arising from the repeated-measures. Scales assessed for pre-post change included the Perceived Stress Scale-10 (PSS) and the Parenting Stress Index-Short Form (PSI). Results General stress, as measured by the PSS, decreased significantly from baseline to post-intervention. Women with the highest baseline general stress level experienced the greatest change in total stress score. A significant change also occurred across the Parental Distress PSI subscale. Conclusions Findings from this innovative interventional study suggest that the addition of MBP within treatment programs for parenting women with substance use disorder is an effective strategy for reducing stress within this at risk population.

  15. Differential Response to Heat Stress in Outer and Inner Onion Bulb Scales.

    Science.gov (United States)

    Galsurker, Ortal; Doron-Faigenboim, Adi; Teper-Bamnolker, Paula; Daus, Avinoam; Lers, Amnon; Eshel, Dani

    2018-05-18

    Brown protective skin formation in onion bulbs can be induced by rapid postharvest heat treatment. Onions that were peeled to different depths and were exposed to heat stress showed that only the outer scale formed dry brown skin, whereas the inner scales maintained high water content and did not change color. Our results reveal that browning of the outer scale during heat treatment is due to an enzymatic process that is associated with high levels of oxidation components, such as peroxidase and quercetin glucoside. De-novo transcriptome analysis revealed differential molecular responses of the outer and inner scales to the heat stress. Genes involved in lipid metabolism, oxidation pathways and cell-wall modification were highly expressed in the outer scale during heating. Defense-response-related genes such as those encoding heat-shock proteins, antioxidative stress defense or production of osmoprotectant metabolites were mostly induced in the inner scale in response to the heat exposure. These transcriptomic data led to a conceptual model that suggests sequential processes for browning development and desiccation of the outer scales versus processes associated with defense response and heat tolerance in the inner scale. Thus, the observed physiological differences between the outer and inner scales is supported by the identified molecular differences.

  16. Maternal stress and distress and child nutritional status.

    Science.gov (United States)

    Rondó, P H C; Rezende, G; Lemos, J O; Pereira, J A

    2013-04-01

    To assess the relationship between maternal stress and distress in pregnancy and 5-8 years postpartum and child nutritional status. Longitudinal cohort study carried out in Jundiai city, Southeast Brazil, involving 409 women followed throughout pregnancy to 5-8 years postpartum, and respective children. Measures of stress and distress were obtained three times in pregnancy (at gestational ages lower than 16 weeks, from 20 to 26 weeks and from 30 to 36 weeks) and 5-8 years postpartum by the Perceived Stress Scale (PSS), General Health Questionnaire (GHQ) and the State-Trait Anxiety Inventories (STAI). The nutritional status of the children was assessed by the World Health Organization body mass index (BMI) z-score for age. The relationship between child BMI z-score for age and scores of the PSS, GHQ and STAI was evaluated by multivariate linear regression, controlling for confounding variables. BMI z-score for age of the children was negatively associated with maternal scores of the PSS 5-8 years postpartum and scores of the GHQ in the second trimester of pregnancy. BMI of the children was positively associated with maternal BMI and birthweight (R(2)=0.13). There was -0.04 (confidence interval -0.07 to -0.9 × 10(-2)) decrease in child BMI per score unit of the PSS increase, and -0.09 (confidence interval -0.18 to -0.6 × 10(-3)) decrease in child BMI per score unit of the GHQ increase. This study detected a relationship between maternal mental and nutritional status and child nutritional status, implying that if the mother is not physically or mentally well, her capacity for caring for her child may be impaired.

  17. A large-scale perspective on stress-induced alterations in resting-state networks

    Science.gov (United States)

    Maron-Katz, Adi; Vaisvaser, Sharon; Lin, Tamar; Hendler, Talma; Shamir, Ron

    2016-02-01

    Stress is known to induce large-scale neural modulations. However, its neural effect once the stressor is removed and how it relates to subjective experience are not fully understood. Here we used a statistically sound data-driven approach to investigate alterations in large-scale resting-state functional connectivity (rsFC) induced by acute social stress. We compared rsfMRI profiles of 57 healthy male subjects before and after stress induction. Using a parcellation-based univariate statistical analysis, we identified a large-scale rsFC change, involving 490 parcel-pairs. Aiming to characterize this change, we employed statistical enrichment analysis, identifying anatomic structures that were significantly interconnected by these pairs. This analysis revealed strengthening of thalamo-cortical connectivity and weakening of cross-hemispheral parieto-temporal connectivity. These alterations were further found to be associated with change in subjective stress reports. Integrating report-based information on stress sustainment 20 minutes post induction, revealed a single significant rsFC change between the right amygdala and the precuneus, which inversely correlated with the level of subjective recovery. Our study demonstrates the value of enrichment analysis for exploring large-scale network reorganization patterns, and provides new insight on stress-induced neural modulations and their relation to subjective experience.

  18. Development of the Family Stigma Stress Scale (FSSS) for Detecting Stigma Stress in Caregivers of People With Mental Illness.

    Science.gov (United States)

    Chang, Chih-Cheng; Su, Jian-An; Chang, Kun-Chia; Lin, Chung-Ying; Koschorke, Mirja; Rüsch, Nicolas; Thornicroft, Graham

    2017-01-01

    People with mental illness and their family caregivers often perceive public stigma, which may lead to stigma-related stress (or stigma stress). However, no instruments have been developed to measure this stress for family caregivers of people with mental illness. We modified an instrument that measures the stigma stress of people with mental illness (i.e., the cognitive appraisal of stigma as a stressor) and examined the psychometric properties of the scores of the newly developed instrument: the Family Stigma Stress Scale (FSSS). Primary family caregivers of people with mental illness in Southern Taiwan ( n = 300; mean age = 53.08 ± 13.80; 136 males) completed the FSSS. An exploratory factor analysis showed that the FSSS score had two factors; both factor scores had excellent internal consistency (α = .913 and .814) and adequate test-retest reliability ( r = .627 and .533; n = 197). Significant correlations between FSSS factor scores and other instruments supported its concurrent validity and the ability of the FSSS to differentiate between clinical characteristics, for example, having been previously hospitalized or not. The FSSS is a brief and effective measure of the stigma stress of family caregivers of people with mental illness.

  19. Vocational satisfaction, coping strategies, and perceived stress as factors of ‘burnout’ in clinical dental students.

    Directory of Open Access Journals (Sweden)

    Francisco Pérez

    2013-12-01

    Full Text Available Having discussed different factors contributing towards “Burnout Syndrome” (BOS in dentistry students, the aim of this project is to analyze the existing relationship between vocational satisfaction, coping strategies and perceived stress as determining factors of burnout in 4th and 5th year dentistry students. Methods: Prospective cohort study (March-December. The relationship between vocational satisfaction, coping strategies and perceived stress as factors towards BOS in 4th and 5th year dentistry students will be determined. All participants will be required to sign a consent form the project will be evaluated by the Ethics Committee. The sociodemographic variables to be measured are: age, gender and socioeconomic status; the psychological variables are: Burnout Syndrome severity, using Maslach Burnout Inventory (MBI, coping strategies by Copyng Strategies Inventory (CSI, perceived stress with Perceived Stress Scale Questionnaire (PSS. All versions above have been validated in Spanish, and vocational satisfaction of the Dentistry Degree will be measured using a questionnaire, with 6 questions for 3 parameters: career choice, current feeling and predicted feeling after graduation. The data collection will be carried out in 4 stages: informed consent obtainment; MBI, CSI, PSS scales and vocational satisfaction questionnaire in March. In the second (June, third (September and fourth (November stages, the questionnaires will be repeated: MBI, PSS and vocational satisfaction. The findings and analysis will be processed in STATA 10/SE including descriptive statistics, regression models, measures and tests of association.

  20. The scaling of stress distribution under small scale yielding by T-scaling method and application to prediction of the temperature dependence on fracture toughness

    International Nuclear Information System (INIS)

    Ishihara, Kenichi; Hamada, Takeshi; Meshii, Toshiyuki

    2017-01-01

    In this paper, a new method for scaling the crack tip stress distribution under small scale yielding condition was proposed and named as T-scaling method. This method enables to identify the different stress distributions for materials with different tensile properties but identical load in terms of K or J. Then by assuming that the temperature dependence of a material is represented as the stress-strain relationship temperature dependence, a method to predict the fracture load at an arbitrary temperature from the already known fracture load at a reference temperature was proposed. This method combined the T-scaling method and the knowledge “fracture stress for slip induced cleavage fracture is temperature independent.” Once the fracture load is predicted, fracture toughness J c at the temperature under consideration can be evaluated by running elastic-plastic finite element analysis. Finally, the above-mentioned framework to predict the J c temperature dependency of a material in the ductile-to-brittle temperature distribution was validated for 0.55% carbon steel JIS S55C. The proposed framework seems to have a possibility to solve the problem the master curve is facing in the relatively higher temperature region, by requiring only tensile tests. (author)

  1. Systematic Approach to Formulate PSS Development Project Proposals in the Fuzzy Front End

    DEFF Research Database (Denmark)

    Barquet, Ana Paula B.; Pigosso, Daniela Cristina Antelmi; Rozenfeld, Henrique

    2013-01-01

    be considered by companies during this definition. The systematization of PSS attributes may help increase the knowledge about different PSS projects that can emerge in the front end, thus leading to the discovery of opportunities that are not apparent in the existing business models and give rise to new ideas...

  2. Business-IT alignment in PSS value networks : a capability-based framework

    NARCIS (Netherlands)

    Bagheri, S.; Kusters, R.J.; Trienekens, J.J.M.; Camarinha-Matos, L.M.; Afsarmanesh, H.

    2014-01-01

    Advanced information technology (IT) is regarded as a foundation for the operation of product-service system (PSS) value networks. This requires alignment between IT and PSS business strategy. Business‐IT alignment (BIA) in a value network can raise the ability of partners to collaborate effectively

  3. Conductivity, work function, and environmental stability of PEDOT:PSS thin films treated with sorbitol

    NARCIS (Netherlands)

    Nardes, A.M.; Kemerink, M.; Kok, de M.M.; Vinken, E.; Maturova, K.; Janssen, R.A.J.

    2008-01-01

    The electrical properties of poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) thin films deposited from aqueous dispersion using different concentrations of sorbitol have been studied in detail. Although it is well known that sorbitol enhances the conductivity of PEDOT:PSS thin

  4. Step-by-step towards PSS – Evaluating, Deciding and Executing

    DEFF Research Database (Denmark)

    Neugebauer, Line Maria; Mougaard, Krestine; McAloone, Tim C.

    2012-01-01

    Successful implementation of product-service system (PSS) as business strategy has proven lucrative through many industry examples. However, companies should tread carefully before committing to a costly restructuring towards PSS business creation. This paper claims that before a company moves fr...

  5. Investigation of independent verification and validation of the servicemen occupational stress scale

    Directory of Open Access Journals (Sweden)

    Jia XU

    2012-12-01

    Full Text Available Objective  To examine the reliability and validity of the servicemen occupational stress scale. Methods  A survey with the servicemen occupational stress scale was carried out on 1100 randomly chosen military personnel in the army, and 106 among them also underwent examination with Chinese Military Mental Health Scale (CMMHS at the same time. Results  The Cronbach's α coefficient of total scale was 0.929, and subscales were 0.731-0.857 (P<0.01; the half reliability of total scale was 0.932, and subscales were 0.465-0.881 (P<0.01. The correlation coefficients among factors and between factors and total scale score were 0.699-0.900 (P<0.01. The factors of the servicemen occupational stress scale showed a significant correlation with most factors of the CMMHS, the correlation coefficients were 0.186-0253. According to the results of exploratory factor analysis, it was showed that the scale of the entries in the collation and factors named were more reasonable. According to the results of confirmatory factor analysis, there was a higher degree of accordance between the sample data and the hypothesized structure of factors, with Chi-Square statistic equal to 8293.0, RMSEA (root mean square error of approximation equal to 0.055, RMR (root mean square residual equal to 0.031, TLI (Tucker-Lewis index, CFI (comparative fit index, IFI (incremental fit index and GFI (goodness of fit index 0.919, 0.926, 0.920, 0.915, respectively. Conclusion  The reliability and validity of the servicemen occupational stress scale meet the standards for scale designing.

  6. Perceived stress in patients with migraine: a case-control study.

    Science.gov (United States)

    Moon, Hye-Jin; Seo, Jong-Geun; Park, Sung-Pa

    2017-12-01

    Perceived stress is the most common trigger for migraine. The objective of this study was to examine the clinical significance of perceived stress in migraine patients. This is a case-control study. Consecutive migraine patients who visited a tertiary care hospital were enrolled for this study. They completed self-reported questionnaires including Perceived Stress Scale (PSS), 12-item Allodynia Symptom Checklist (ASC-12), Migraine Disability Assessment Scale (MIDAS), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), Epworth Sleepiness Scale (ESS), Insomnia Severity Index (ISI), and Migraine-Specific Quality of Life Questionnaire (MSQ). Degree of perceived stress in migraine patients was measured and compared to that in healthy controls. Predictors for perceived stress and their impact on quality of life (QOL) of migraine patients were also determined. A total of 227 migraine patients were eligible for this study, including 103 (45.4%) who had chronic migraine (CM). Mean PSS score was significantly (p migraine is a critical factor for perceived stress. Perceived stress affects QOL of migraine patients.

  7. Human estrogen receptor (ESR) gene locus: PssI dimorphism

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, R T; Taylor, J E; Frossard, P M [California Biotechnology Inc., Mountain View, CA (USA); Shine, J J [Garvan Institute, Darlinghurst (Australia)

    1988-07-25

    pESR-2, a 2.1 kb partial cDNA containing the entire translated sequence of the human estrogen receptor mRNA isolated from MCF-7 human breast cancer cells, was subcloned in the Eco RI site of pBR322. PssI (PuGGNCCPy) identifies a single two-allele polymorphism with bands at either 1.7 or 1.4 kb, as well as invariant bands at 12.6, 9.3, 4.1, 3.7, 2.4, 2.2, and 1.2 kb. Its frequency was studied in 77 unrelated North American Caucasians. The human estrogen receptor gene has been localized to 6q24 -- q27 by in situ hybridization. Co-dominant segregation is demonstrated in one family (8 individuals).

  8. Adaptation to Portuguese of the Depression, Anxiety and Stress Scales (DASS).

    Science.gov (United States)

    Apóstolo, João Luís Alves; Mendes, Aida Cruz; Azeredo, Zaida Aguiar

    2006-01-01

    To adapt to Portuguese, of Portugal, the Depression, Anxiety and Stress Scales, a 21-item short scale (DASS 21), designed to measure depression, anxiety and stress. After translation and back-translation with the help of experts, the DASS 21 was administered to patients in external psychiatry consults (N=101), and its internal consistency, construct validity and concurrent validity were measured. The DASS 21 properties certify its quality to measure emotional states. The instrument reveals good internal consistency. Factorial analysis shows that the two-factor structure is more adequate. The first factor groups most of the items that theoretically assess anxiety and stress, and the second groups most of the items that assess depression, explaining, on the whole, 58.54% of total variance. The strong positive correlation between the DASS 21 and the Hospital Anxiety and Depression scale (HAD) confirms the hypothesis regarding the criterion validity, however, revealing fragilities as to the divergence between theoretically different constructs.

  9. Industry specific PSS: A study of opportunities and barriers for maritime suppliers

    DEFF Research Database (Denmark)

    Andersen, Jakob Axel Bejbro; McAloone, Tim C.; Garcia i Mateu, Adrià

    2013-01-01

    Product-Service System (PSS) business models are finding applications with suppliers and manufacturers across industries, but the models have yet to establish a strong foothold in the maritime sector. A number of metrics for evaluating the attractiveness of PSS business models have been proposed...... in chiefly design research and operations management literature. This paper applies a number of these metrics to the maritime sector using data from a number of maritime suppliers. It is found that the industry is, at least in some aspects, attractive from this PSS metrics standpoint. To explain the inherent...... lack of PSS maturity in the industry despite this metrics-based conclusion, the discussion moves beyond the quantitative factors and considers a number of organisational, structural and cultural issues that stand in the way of PSS. This paper is based on the initial responses provided by maritime...

  10. Sammenhaenge mellem risikoadfaerd for spiseforstyrrelser og Short Form-36 samt selvoplevet stress blandt 16-29-årige danske kvinder

    DEFF Research Database (Denmark)

    Waaddegaard, Mette; Davidsen, Michael; Kjøller, Mette

    2009-01-01

    disorders and also to SF-36 and Perceived Stress Scale (PSS). RESULTS: Women with risk behaviour for eating disorders have a lower score on all subscales of SF-36 than women without risk behaviour. The differences are significant for the subscales for mental health, vitality, social function and general...... health. They also have a higher mean score on PSS than women without risk behaviour. CONCLUSION: Women with risk behaviour for eating disorders have lower mental health-related life quality than women without risk behaviour. They also experience daily life as more unpredictable, stressful and difficult......INTRODUCTION: To improve the early identification of eating disorders the study tested whether women with risk behaviour for eating disorders have lower health-related life quality and more perceived stress than women without risk behaviour. MATERIAL AND METHODS: The study was a representative...

  11. Teacher Stress Inventory: validation of the Greek version and perceived stress levels among 3,447 educators

    Directory of Open Access Journals (Sweden)

    Kourmousi N

    2015-03-01

    Full Text Available Ntina Kourmousi, Christina Darviri, Liza Varvogli, Evangelos C Alexopoulos School of Medicine, University of Athens, Athens, Greece Background: The Teacher Stress Inventory (TSI is an instrument for measuring occupational stress in teachers. This study aimed to translate and adapt it for use in Greece, and then assess its reliability and validity. Methods: The Greek versions of the TSI and the 14-item Perceived Stress Scale (PSS-14 were posted on all Greek educators' official sites during May 2012. A nationwide sample of 3,447 teachers of all levels and specialties completed the questionnaires via the Internet. Reliability was determined by the calculation of Cronbach's alpha coefficient. Confirmatory factor analysis was conducted and validity was further examined by investigating the correlation of the TSI with the PSS-14 and their association with demographics and work-related factors. Results: Satisfactory Cronbach's alpha values (above 0.70 were found for all TSI dimensions. Confirmatory factor analysis confirmed the two-factor construct of TSI (root mean square error of approximation, comparative fit index, and goodness-of-fit index values were 0.079, 0.956, and 0.951, respectively, confirming the pre-established theory for the two latent variables, Stress Sources and Stress Manifestations. Significant correlations were found between TSI subscales, PSS-14 sex, age, lack of support, and students' difficulties. Conclusion: The Greek version of the TSI was found to have satisfactory psychometric properties, and its use for assessing stress in Greek teachers is warranted. Keywords: TSI, reliability, validity, Greek educators, occupational stress, psychosocial factors

  12. Changes in stress and coping from a randomized controlled trial of a three-month stress management intervention

    DEFF Research Database (Denmark)

    Willert, M.V.; Thulstrup, A.M.; Hertz, J.

    2009-01-01

    Objectives The aim of this study was to investigate whether it group-based stress management intervention, based on principles from cognitive behavior therapy, call reduce stress and alter coping strategies in an occupationally diverse population with extensive symptoms of work-related stress....... Methods Using a randomized wait list control design, 102 participants were divided into two groups: intervention and wait list control. The intervention was a three-month group-based stress management program. Outcomes measures were the Perceived Stress Scale (PSS-10, range 0-40 points) and five......% Cl -0.89-0.07) favouring the intervention. The gains achieved during treatment were maintained when followed up three months later. Conclusions Treatment is Superior to the control condition in positively affecting perceived stress and positive reframing. When followed up, the gains achieved...

  13. The psychometric properties of the Perceived Stress Scale-10 among patients with systemic lupus erythematosus.

    Science.gov (United States)

    Mills, S D; Azizoddin, D; Racaza, G Z; Wallace, D J; Weisman, M H; Nicassio, P M

    2017-10-01

    Objective Systemic lupus erythematosus (SLE) is a chronic, multisystem autoimmune disease characterized by periods of remission and recurrent flares, which have been associated with stress. Despite the significance of stress in this disease, the Perceived Stress Scale-10 has yet to be psychometrically evaluated in patients with SLE. Methods Exploratory factor analysis was used to examine the structural validity of the Perceived Stress Scale-10 among patients with SLE ( N = 138) receiving medical care at Cedars Sinai Medical Center. Cronbach's coefficient alpha was used to examine internal consistency reliability, and Pearson product-moment correlations were used to examine convergent validity with measures of anxiety, depression, helplessness, and disease activity. Results Exploratory factor analysis provided support for a two-factor structure (comparative fit index = .95; standardized root mean residual = .04; root mean square error of approximation = .08). Internal consistency reliability was good for both factors (α = .84 and .86). Convergent validity was evidenced via significant correlations with measures of anxiety, depression, and helplessness. There were no significant correlations with the measure of disease activity. Conclusion The Perceived Stress Scale-10 can be used to examine perceived stress among patients with SLE.

  14. Homogeneity of small-scale earthquake faulting, stress, and fault strength

    Science.gov (United States)

    Hardebeck, J.L.

    2006-01-01

    Small-scale faulting at seismogenic depths in the crust appears to be more homogeneous than previously thought. I study three new high-quality focal-mechanism datasets of small (M angular difference between their focal mechanisms. Closely spaced earthquakes (interhypocentral distance scales, the crustal stress orientation and fault strength (coefficient of friction) are inferred to be homogeneous as well, to produce such similar earthquakes. Over larger length scales (???2-50 km), focal mechanisms become more diverse with increasing interhypocentral distance (differing on average by 40-70??). Mechanism variability on ???2- to 50 km length scales can be explained by ralatively small variations (???30%) in stress or fault strength. It is possible that most of this small apparent heterogeneity in stress of strength comes from measurement error in the focal mechanisms, as negligibble variation in stress or fault strength (<10%) is needed if each earthquake is assigned the optimally oriented focal mechanism within the 1-sigma confidence region. This local homogeneity in stress orientation and fault strength is encouraging, implying it may be possible to measure these parameters with enough precision to be useful in studying and modeling large earthquakes.

  15. Stress and adhesion of chromia-rich scales on ferritic stainless steels in relation with spallation

    Directory of Open Access Journals (Sweden)

    A. Galerie

    2004-03-01

    Full Text Available The relation between chromia scale spallation during oxidation or cooling down of ferritic stainless steels is generally discussed in terms of mechanical stresses induced by volume changes or differential thermal expansion. In the present paper, growth and thermal stress measurements in scales grown on different ferritic steel grades have shown that the main stress accumulation occurs during isothermal scale growth and that thermal stresses are of minor importance. However, when spallation occurs, it is always during cooling down. Steel-oxide interface undulation seems to play a major role at this stage, thus relating spallation to the metal mechanical properties, thickness and surface preparation. A major influence on spallation of the minor stabilizing elements of the steels was observed which could not be related to any difference in stress state. Therefore, an original inverted blister test was developed to derive quantitative values of the metal-oxide adhesion energy. These values clearly confirmed that this parameter was influenced by scale thickness and by minor additions, titanium greatly increasing adhesion whereas niobium decreased it.

  16. Large-Scale Parallel Finite Element Analysis of the Stress Singular Problems

    International Nuclear Information System (INIS)

    Noriyuki Kushida; Hiroshi Okuda; Genki Yagawa

    2002-01-01

    In this paper, the convergence behavior of large-scale parallel finite element method for the stress singular problems was investigated. The convergence behavior of iterative solvers depends on the efficiency of the pre-conditioners. However, efficiency of pre-conditioners may be influenced by the domain decomposition that is necessary for parallel FEM. In this study the following results were obtained: Conjugate gradient method without preconditioning and the diagonal scaling preconditioned conjugate gradient method were not influenced by the domain decomposition as expected. symmetric successive over relaxation method preconditioned conjugate gradient method converged 6% faster as maximum if the stress singular area was contained in one sub-domain. (authors)

  17. Product/Service-System Origins and Trajectories: A Systematic Literature Review of PSS Definitions and their Characteristics

    DEFF Research Database (Denmark)

    Haase, Ronja P.; Pigosso, Daniela Cristina Antelmi; McAloone, Tim C.

    2017-01-01

    Literature provides multiple definitions on Product/Service-Systems (PSS), and as the field develops, certain trajectories emerge. The purpose ofthis article is to provide an overview of the stabilization of PSS definitions within PSS research, by presenting the most prominent PSS definitionsand...... their interrelationships. As the result of a strict protocol, the paper identifies 52 prominent definitions related to PSS, where the citationrelations between the prominent definitions are studied and graphically illustrated. The definitions are furthermore analyzed to identify commonPSS definition characteristics...... and eleven different characteristics identified. Descriptive analysis is carried out on the identified PSS definitioncharacteristics, to determine commonalties and differences in the field. Even though the literature provides many different variations of PSS definitions, there is certain convergence...

  18. Characteristics of the Residual Stress tensor when filter width is larger than the Ozmidov scale

    Science.gov (United States)

    de Bragança Alves, Felipe Augusto; de Bruyn Kops, Stephen

    2017-11-01

    In stratified turbulence, the residual stress tensor is statistically anisotropic unless the smallest resolved length scale is smaller than the Ozmidov scale and the buoyancy Reynolds number is sufficiently high for there to exist a range of scales that is statistically isotropic. We present approximations to the residual stress tensor that are derived analytically. These approximations are evaluated by filtering data from direct numerical simulations of homogeneous stratified turbulence, with unity Prandtl number, resolved on up to 8192 × 8192 × 4096 grid points along with an isotropic homogeneous case resolved on 81923 grid points. It is found that the best possible scaling of the strain rate tensor yields a residual stress tensor (RST) that is less well statistically aligned with the exact RST than a randomly generated tensor. It is also found that, while a scaling of the strain rate tensor can dissipate the right amount of energy, it produces incorrect anisotropic dissipation, removing energy from the wrong components of the velocity vector. We find that a combination of the strain rate tensor and a tensor related to energy redistribution caused by a Newtonian fluid viscous stress yields an excellent tensorial basis for modelling the RST.

  19. Patterns and determinants of stress among consultant physicians working in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Alosaimi FD

    2018-03-01

    Full Text Available Fahad D Alosaimi,1 Hossam S Alawad,2 Ayedh K Alamri,2 Abdullah I Saeed,2 Khalid A Aljuaydi,2 Alwaleed S Alotaibi,2 Khalid M Alotaibi,2 Eiad A Alfaris3 1Department of Psychiatry, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia; 2Department of Psychiatry, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia; 3King Saud University Chair for the Development of Medical Education, Department of Family and Community Medicine, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia Background: Physicians experience several work-related stressors that have been mounting up in recent decades. This study aimed to examine perceived stress and its risk factors and consequences among consultant physicians in Saudi Arabia. Methods: A cross-sectional study was conducted from November 2014 to March 2015 among physicians who were assigned rank of consultant. The stress level was assessed using perceived stress scale (PSS.Results: A total of 582 consultants participated. The average age was 46.9±7.9 years, 71% were males, 56% were Saudi, 15% were smokers, and 68% slept ≤6 hours per night. The median PSS score was 17 (interquartile range of 14–21, which represented 44% of maximum possible PSS score. The upper tertile of PSS score (represents a high stress level was significantly associated with being younger, female, and Saudi. The majority (85% considered job environment to be stressful and ~50% attributed that to a high workload and a noncooperative administration. In the year preceding this study, half of consultants frequently contemplated or even worked toward changing their medical institutes or even moving to work outside Saudi Arabia because of perception of a stressful working environment. Over the previous year, encountering life stressors, considering job environment as stressful and experiencing passive suicidal ideation, were significantly associated with higher levels of stress

  20. Groundwater development stress: Global-scale indices compared to regional modeling

    Science.gov (United States)

    Alley, William; Clark, Brian R.; Ely, Matt; Faunt, Claudia

    2018-01-01

    The increased availability of global datasets and technologies such as global hydrologic models and the Gravity Recovery and Climate Experiment (GRACE) satellites have resulted in a growing number of global-scale assessments of water availability using simple indices of water stress. Developed initially for surface water, such indices are increasingly used to evaluate global groundwater resources. We compare indices of groundwater development stress for three major agricultural areas of the United States to information available from regional water budgets developed from detailed groundwater modeling. These comparisons illustrate the potential value of regional-scale analyses to supplement global hydrological models and GRACE analyses of groundwater depletion. Regional-scale analyses allow assessments of water stress that better account for scale effects, the dynamics of groundwater flow systems, the complexities of irrigated agricultural systems, and the laws, regulations, engineering, and socioeconomic factors that govern groundwater use. Strategic use of regional-scale models with global-scale analyses would greatly enhance knowledge of the global groundwater depletion problem.

  1. Work-related stress and role of personality in a sample of Italian bus drivers.

    Science.gov (United States)

    Bergomi, Margherita; Modenese, Alberto; Ferretti, Enrica; Ferrari, Angela; Licitra, Giuseppe; Vivoli, Roberto; Gobba, Fabriziomaria; Aggazzotti, Gabriella

    2017-01-01

    Several studies have shown that professional drivers are at risk of developing work-related stress. Stress may be responsible for a variety of adverse effects and may also be associated with an increased number of accidents. Perform an integrated, objective and subjective evaluation of work-related stress in bus drivers, that also considered the role of personality traits. Salivary α-amylase and cortisol were measured in 42 bus drivers. Subjective stress evaluation was performed with the Perceived Stress Scale (PSS-10) and Driver Stress Inventory (DSI). To evaluate personality traits, we administered the Eysenck Personality Questionnaire-Revised (EPQ-R) and the Impulsivity Inventory (IVE). Salivary biomarkers showed no associations with PSS-10 and personality traits. Cortisol levels were positively correlated with fatigue (r = 0.44) at the middle of the work-shift and with aggression (r = 0.51) at the end of a day off. At the end of the work-shift, cortisol levels were negatively correlated with hazard monitoring (r = -0.37) and salivary α-amylase was positively correlated with thrill-seeking (r = 0.36). Neuroticism (β= 0.44) and impulsiveness (β= 0.38) were predictors of perceived stress by multiple regression. An integrated method, considering both objective and subjective indicators, seems adequate to evaluate work-related stress in professional drivers. Personality traits are relevant in determining perception of stress.

  2. Validation of the Minority Stress Scale Among Italian Gay and Bisexual Men.

    Science.gov (United States)

    Pala, Andrea Norcini; Dell'Amore, Francesca; Steca, Patrizia; Clinton, Lauren; Sandfort, Theodorus; Rael, Christine

    2017-12-01

    The experience of sexual orientation stigma (e.g., homophobic discrimination and physical aggression) generates minority stress, a chronic form of psychosocial stress. Minority stress has been shown to have a negative effect on gay and bisexual men's (GBM's) mental and physical health, increasing the rates of depression, suicidal ideation, and HIV risk behaviors. In conservative religious settings, such as Italy, sexual orientation stigma can be more frequently and/or more intensively experienced. However, minority stress among Italian GBM remains understudied. The aim of this study was to explore the dimensionality, internal reliability, and convergent validity of the Minority Stress Scale (MSS), a comprehensive instrument designed to assess the manifestations of sexual orientation stigma. The MSS consists of 50 items assessing (a) Structural Stigma, (b) Enacted Stigma, (c) Expectations of Discrimination, (d) Sexual Orientation Concealment, (e) Internalized Homophobia Toward Others, (f) Internalized Homophobia toward Oneself, and (g) Stigma Awareness. We recruited an online sample of 451 Italian GBM to take the MSS. We tested convergent validity using the Perceived Stress Questionnaire. Through exploratory factor analysis, we extracted the 7 theoretical factors and an additional 3-item factor assessing Expectations of Discrimination From Family Members. The MSS factors showed good internal reliability (ordinal α > .81) and good convergent validity. Our scale can be suitable for applications in research settings, psychosocial interventions, and, potentially, in clinical practice. Future studies will be conducted to further investigate the properties of the MSS, exploring the association with additional health-related measures (e.g., depressive symptoms and anxiety).

  3. Construction and evaluation of a self rating scale for stress-induced exhaustion disorder, the Karolinska Exhaustion Disorder Scale.

    Science.gov (United States)

    Besèr, Aniella; Sorjonen, Kimmo; Wahlberg, Kristina; Peterson, Ulla; Nygren, Ake; Asberg, Marie

    2014-02-01

    Prolonged stress (≥ six months) may cause a condition which has been named exhaustion disorder (ED) with ICD-10 code F43.8. ED is characterised by exhaustion, cognitive problems, poor sleep and reduced tolerance to further stress. ED can cause long term disability and depressive symptoms may develop. The aim was to construct and evaluate a self-rating scale, the Karolinska Exhaustion Disorder Scale (KEDS), for the assessment of ED symptoms. A second aim was to examine the relationship between self-rated symptoms of ED, depression, and anxiety using KEDS and the Hospital Anxiety and Depression Scale (HAD). Items were selected based on their correspondence to criteria for ED as formulated by the Swedish National Board of Health and Welfare (NBHW), with seven response alternatives in a Likert-format. Self-ratings performed by 317 clinically assessed participants were used to analyse the scale's psychometric properties. KEDS consists of nine items with a scale range of 0-54. Receiver operating characteristics analysis demonstrated that a cut-off score of 19 was accompanied by high sensitivity and specificity (each above 95%) in the discrimination between healthy subjects and patients with ED. Reliability was satisfactory and confirmatory factor analysis revealed that ED, depression and anxiety are best regarded as different phenomena. KEDS may be a useful tool in the assessment of symptoms of Exhaustion Disorder in clinical as well as research settings. There is evidence that the symptom clusters of ED, anxiety and depression, respectively, reflect three different underlying dimensions. © 2013 The Authors. Scandinavian Journal of Psychology published by Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  4. Depression, Anxiety and Stress Scale (DASS): The Study of Validity and Reliability

    Science.gov (United States)

    Basha, Ertan; Kaya, Mehmet

    2016-01-01

    The purpose of this study is to examine validity and reliability of the Albanian version of the Depression, Anxiety and Stress Scale (DASS), which is developed by Lovibond and Lovibond (1995). The sample of this study is consisted of 555 subjects who were living in Kosovo. The results of confirmatory factor analysis indicated 42 items loaded on…

  5. Psychometric Properties of the Depression Anxiety and Stress Scale-21 in Older Primary Care Patients

    OpenAIRE

    Gloster, Andrew T.; Rhoades, Howard M.; Novy, Diane; Klotsche, Jens; Senior, Ashley; Kunik, Mark; Wilson, Nancy; Stanley, Melinda A.

    2008-01-01

    The Depression Anxiety Stress Scale (DASS) was designed to efficiently measure the core symptoms of anxiety and depression and has demonstrated positive psychometric properties in adult samples of anxiety and depression patients and student samples. Despite these findings, the psychometric properties of the DASS remain untested in older adults, for whom the identification of efficient measures of these constructs is especially important.

  6. Suitability of the Depression, Anxiety, and Stress Scale in Parkinson's Disease.

    Science.gov (United States)

    Johnson, Andrew R; Lawrence, Blake J; Corti, Emily J; Booth, Leon; Gasson, N; Thomas, Meghan G; Loftus, A M; Bucks, Romola S

    2016-05-27

    The Depression, Anxiety, and Stress Scale -21 (DASS-21) is a frequently used measure of emotional disturbance symptoms in Parkinson's disease (PD). However, the factor structure of the DASS-21 in PD has yet to be explored. To assess whether the scale is measuring these symptoms in PD in the same way as the general population. The present study fit a series of established DASS-21 factor structures with both confirmatory factor analysis (CFA) and exploratory structural equation modelling (ESEM) using data from 251 participants with PD. The 3-factor ESEM provided the best fit. The depression and stress scales fit well, however, few items on the anxiety subscale loaded clearly, with several items significantly loading onto the depression or stress factors. Whilst the depression and stress subscales appear suitable in PD, poor loadings and internal consistency indicate the anxiety subscale may not accurately assess anxiety symptomology in PD. This may be due to the scale's reliance on physiological symptoms as indicators of anxiety, when many of these are present in PD. Thus, the anxiety subscale of the DASS-21 may not be a suitable measure of anxiety in PD.

  7. Using the Depression, Anxiety, Stress Scales-21 with U.S. Adolescents: An Alternate Models Analysis

    Science.gov (United States)

    Moore, Stephanie A.; Dowdy, Erin; Furlong, Michael J.

    2017-01-01

    As part of universal screening efforts in schools, validated measures that identify internalizing distress are needed. One promising available measure, the Depression, Anxiety, and Stress Scales-21 (DASS-21), has yet to be thoroughly investigated with adolescents in the United States. This study investigated the underlying factor structure of the…

  8. The MMPI-2 Restructured Clinical Scales in the Assessment of Posttraumatic Stress Disorder and Comorbid Disorders

    Science.gov (United States)

    Wolf, Erika J.; Miller, Mark W.; Orazem, Robert J.; Weierich, Mariann R.; Castillo, Diane T.; Milford, Jaime; Kaloupek, Danny G.; Keane, Terence M.

    2008-01-01

    This study examined the psychometric properties of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Restructured Clinical Scales (RCSs) in individuals with posttraumatic stress disorder (PTSD) receiving clinical services at Department of Veterans Affairs medical centers. Study 1 included 1,098 men who completed the MMPI-2 and were…

  9. EARLY PROGNOSTIC SCREENING FOR POSTTRAUMATIC STRESS DISORDER WITH THE DAVIDSON TRAUMA SCALE AND THE SPAN

    NARCIS (Netherlands)

    Sijbrandij, Marit; Olff, Miranda; Opmeer, Brent C.; Carlier, Ingrid V. E.; Gersons, Berthold P. R.

    2008-01-01

    Background: This study examined the accuracy of the 17-item. Dutch version of the Davidson Trauma Scale (DTS) and the four-item SPAN (Startle, Physiological Arousal, Anger and Numbness) to detect survivors at risk for posttraumatic stress disorder (PTSD) within the first 2 weeks after the trauma.

  10. Psychometric Properties of an Arabic Version of the Depression Anxiety Stress Scales (DASS)

    Science.gov (United States)

    Moussa, Miriam Taouk; Lovibond, Peter; Laube, Roy; Megahead, Hamido A.

    2017-01-01

    Objective: To translate and evaluate the psychometric properties of an Arabic-language version of the Depression Anxiety Stress Scales (DASS). Method: The items were translated, back translated, refined, and tested in an Australian immigrant sample (N = 220). Results: Confirmatory factor analysis showed that the Arabic DASS discriminates between…

  11. Chinese version of the Perceived Stress Scale-10: A psychometric study in Chinese university students.

    Science.gov (United States)

    Lu, Wei; Bian, Qian; Wang, Wenzheng; Wu, Xiaoling; Wang, Zhen; Zhao, Min

    2017-01-01

    Chinese university students often suffer from acute stress, which can affect their mental health. We measured and evaluated perceived stress in this population using the Simplified Chinese version of the 10-item Perceived Stress Scale (SCPSS-10). The SCPSS-10, Patient Health Questionnaire (PHQ), and Generalized Anxiety Disorder 7-item scale (GAD-7) were conducted in 1096 university students. Two weeks later, 129 participants were re-tested using the SCPSS-10. Exploratory factor analysis yielded two factors with Eigen values of 4.76 and 1.48, accounting for 62.41% of the variance. Confirmatory factor analysis demonstrated good fit of this two-factor model. The internal consistency reliability, as measured by Cronbach's α, was 0.85. The test-retest reliability coefficient was 0.7. The SCPSS-10 exhibited high correlation with the PHQ-9 and GAD-7, indicating an acceptable concurrent validity. The SCPSS-10 exhibited satisfactory psychometric properties in Chinese university students.

  12. Enhanced thermoelectric properties of PEDOT/PSS/Te composite films treated with H2SO4

    International Nuclear Information System (INIS)

    Song, Haijun; Cai, Kefeng; Shen, Shirley

    2016-01-01

    Firstly, tellurium (Te) nanorods with a high Seebeck coefficient have been integrated into a conducting polymer PEDOT/PSS to form PEDOT/PSS/Te composite films. The Seebeck coefficient of the PEDOT/PSS/Te (90 wt.%) composite films is ~191 μV/K, which is about 13 times greater than that of pristine PEDOT/PSS. Then, H 2 SO 4 treatment has been used to further tune the thermoelectric properties of the composite films by adjusting the doping level and increasing the carrier concentration. After the acid treatment, the electrical conductivity of the composite films has increased from 0.22 to 1613 S/cm due to the removal of insulating PSS and the structural rearrangement of PEDOT. An optimized power factor of 42.1 μW/mK 2 has been obtained at room temperature for a PEDOT/PSS/Te (80 wt.%) sample, which is about ten times larger than that of the untreated PEDOT/PSS/Te composite film.

  13. Nozzle Printed-PEDOT:PSS for Organic Light Emitting Diodes with Various Dilution Rates of Ethanol

    Directory of Open Access Journals (Sweden)

    Dai Geon Yoon

    2018-01-01

    Full Text Available In this study, we investigated the ink formulation of poly(3,4-ethylenedioxythiophene polystyrene sulfonate (PEDOT:PSS as the hole injection layer (HIL in an organic light emitting diode (OLED structure. Generally, in a PEDOT:PSS solution, water is incorporated in the solution for the solution process. However, the fabrication of thin film which contained the water, main solvent, could not easily form by using printing technology except spin-coating process because of the high surface tension of water. On the other hand, mixing PEDOT:PSS solution and ethanol (EtOH, a dilution solvent, could restrain the non-uniform layer that forms by the high surface tension and low volatility of water. Therefore, we printed a PEDOT:PSS solution with various concentrations of EtOH by using a nozzle printer and obtained a uniform pattern. The line width of PEDOT:PSS diluted with 90% (volume ratio ehtanol was measured as about 4 mm with good uniformity with a 0.1 mm nozzle. Also, imaging software and a scanning electron microscope (SEM were used to measure the uniformity of PEDOT:PSS coated on a substrate. Finally, we fabricated a green phosphorescent OLED device with printed-PEDOT:PSS with specific concentrations of EtOH and we achieved a current efficiency of 27 cd/A with uniform quality of luminance in the case of device containing 90% EtOH.

  14. PEDOT:PSS-Containing Nanohydroxyapatite/Chitosan Conductive Bionanocomposite Scaffold: Fabrication and Evaluation

    Directory of Open Access Journals (Sweden)

    Alireza Lari

    2016-01-01

    Full Text Available Conductive poly(3,4-ethylenedioxythiophene-poly(4-styrene sulfonate (PEDOT:PSS was incorporated into nanohydroxyapatite/chitosan (nHA/CS composite scaffolds through a freezing and lyophilization technique. The bionanocomposite conductive scaffold was then characterized using several techniques. A scanning electron microscope image showed that the nHA and PEDOT:PSS were dispersed homogeneously in the chitosan matrix, which was also confirmed by energy-dispersive X-ray (EDX analysis. The conductive properties were measured using a digital multimeter. The weight loss and water-uptake properties of the bionanocomposite scaffolds were studied in vitro. An in vitro cell cytotoxicity test was carried out using mouse fibroblast (L929 cells cultured onto the scaffolds. Using a freezing and lyophilization technique, it was possible to fabricate three-dimensional, highly porous, and interconnected PEDOT:PSS/nHA/CS scaffolds with good handling properties. The porosity was 74% and the scaffold’s conductivity was 9.72±0.78 μS. The surface roughness was increased with the incorporation of nHA and PEDOT:PSS into the CS scaffold. The compressive mechanical properties increased significantly with the incorporation of nHA but did not change significantly with the incorporation of PEDOT:PSS. The PEDOT:PSS-containing nHA/CS scaffold exhibited significantly higher cell attachment. The PEDOT:PSS/nHA/CS scaffold could be a potential bionanocomposite conductive scaffold for tissue engineering.

  15. Emotional intelligence, perceived stress and academic performance of Sri Lankan medical undergraduates.

    Science.gov (United States)

    Ranasinghe, P; Wathurapatha, W S; Mathangasinghe, Y; Ponnamperuma, G

    2017-02-20

    Previous research has shown that higher Emotional Intelligence (EI) is associated with better academic and work performance. The present study intended to explore the relationship between EI, perceived stress and academic performance and associated factors among medical undergraduates. This descriptive cross-sectional research study was conducted among 471 medical undergraduates of 2nd, 4th and final years of University of Colombo, Sri Lanka. Students were rated on self administered Perceived Stress Scale (PSS) and Schutte Self-Report Emotional Intelligence Test (SEIT). Examination results were used as the dichotomous outcome variable in a logistic regression analysis. Females had higher mean EI scores (p = 0.014). A positive correlation was found between the EI score and the number of extracurricular activities (r = 0.121, p = 0.008). Those who were satisfied regarding their choice to study medicine, and who were planning to do postgraduate studies had significantly higher EI scores and lower PSS scores (p <0.001). Among final year undergraduates, those who passed the Clinical Sciences examination in the first attempt had a higher EI score (p <0.001) and a lower PSS score (p <0.05). Results of the binary logistic-regression analysis in the entire study population indicated that female gender (OR:1.98) and being satisfied regarding their choice of the medical undergraduate programme (OR:3.69) were significantly associated with passing the examinations. However, PSS Score and engagement in extracurricular activities were not associated with 'Examination Results'. Higher EI was associated with better academic performance amongst final year medical students. In addition a higher EI was observed in those who had a higher level of self satisfaction. Self-perceived stress was lower in those with a higher EI. Enhancing EI might help to improve academic performance among final year medical student and also help to reduce the stress levels and cultivate

  16. Geomechanical effects of stress shadow created by large-scale destress blasting

    Directory of Open Access Journals (Sweden)

    Isaac Vennes

    2017-12-01

    Full Text Available This study aims to determine if large-scale choked panel destress blasting can provide sufficient beneficial stress reduction in highly-stressed remnant ore pillar that is planned for production. The orebody is divided into 20 stopes over 2 levels, and 2 panels are choke-blasted in the hanging wall to shield the ore pillar by creating a stress shadow around it. A linear-elastic model of the mining system is constructed with finite difference code FLAC3D. The effect of destress blasting in the panels is simulated by applying a fragmentation factor (α to the rock mass stiffness and a stress reduction factor (β to the current state of stress in the region occupied by the destress panels. As an extreme case, the destress panel is also modeled as a void to obtain the maximum possible beneficial effects of destressing and stress shadow. Four stopes are mined in the stress shadow of the panels in 6 lifts and then backfilled. The effect of destress blasting on the remnant ore pillar is quantified based on stress change and brittle shear ratio (BSR in the stress shadow zone compared to the base case without destress blasting. To establish realistic rock fragmentation and stress reduction factors, model results are compared to measured stress changes reported for case studies at Fraser and Brunswick mines. A 1.5 MPa immediate stress decrease was observed 20 m away from the panel at Fraser Mine, and a 4 MPa immediate stress decrease was observed 25 m away at Brunswick Mine. Comparable results are obtained from the current model with a rock fragmentation factor α of 0.2 and a stress reduction factor β of 0.8. It is shown that a destress blasting with these parameters reduces the major principal stress in the nearest stopes by 10–25 MPa. This yields an immediate reduction of BSR, which is deemed sufficient to reduce volume of ore at risk in the pillar.

  17. COMPI Fertility Problem Stress Scales is a brief, valid and reliable tool for assessing stress in patients seeking treatment

    DEFF Research Database (Denmark)

    Sobral, Maria P.; Costa, Maria E.; Schmidt, Lone

    2017-01-01

    comparability of fertility-related stress across genders and countries. STUDY DESIGN SIZE, DURATION Cross-sectional study. First, we tested the structure of the COMPI-FPSS. Then, reliability and validity (convergent and discriminant) were examined for the final model. Finally, measurement invariance both across...... genders and cultures was tested. PARTICIPANTS/MATERIALS, SETTING, METHODS Our final sample had 3923 fertility patients (1691 men and 2232 women) recruited in clinical settings from seven different countries: Denmark, China, Croatia, Germany, Greece, Hungary and Sweden. Participants had a mean age of 34......STUDY QUESTION Are the Copenhagen Multi‐Centre Psychosocial Infertility research program Fertility Problem Stress Scales (COMPI-FPSS) a reliable and valid measure across gender and culture? SUMMARY ANSWER The COMPI-FPSS is a valid and reliable measure, presenting excellent or good fit...

  18. Facile Preparation and Enhanced Capacitance of the Ag-PEDOT:PSS/Polyaniline Nanofiber Network for Supercapacitors

    International Nuclear Information System (INIS)

    Patil, Dipali S.; Pawar, Sachin A.; Kim, Jin Hyeok; Patil, Pramod S.; Shin, Jae Cheol

    2016-01-01

    Graphical abstract: Fig. shows the steps involved in the development of the AgNW-PEDOT:PSS/PANI electrode. The bright silver nanocubes were observed onto the PANI nanofibers. This means that during the electrodeposition of PANI, there is an electrostatic interaction between AgNWs and PANI; the AgNWs are segmented into the small nanocubes. These nanocubes are distributed equally all over the interconnected network of the PANI nanofibers. This provides a continuous path for the electrons during the charge/discharge process. - Highlights: • Ag-PEDOT:PSS/PANI hybrid nanostructure was prepared. • Dip coating and electrodeposition techniques are used for electrodes preparation. • Symmetric supercapacitor based on AgNW-PEDOT:PSS/PANI was developed. • The positive synergistic effect of AgNW, PEDOT:PSS and PANI was observed. - Abstract: This paper reports the synthesis of a silver − Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)/Polyaniline(Ag-PEDOT:PSS/PANI)hybrid nanostructure using a simple dip coating technique followed by potentiodynamic electrodeposition to achieve an electrochemical supercapacitor with excellent electrochemical performance. In this sandwich type structure, the Ag nanostructure-blended PEDOT: PSS acts as a current collector, where electrons can be transferred easily through this network to the PANI nanofibers and vice versa. The AgNW-PEDOT:PSS/PANI showed a specific capacitance of 643 Fg −1 at 10 mVs −1 and an energy density of 86.19 Whkg −1 at 0.1 mA, indicating the positive synergistic effect of silver nanowires (AgNW), PEDOT:PSS and PANI. The Ag nanostructure incorporated PEDOT:PSS helps to improve the electronic conductivity and the electrochemical stability of the PANI electrodes. Promising electrochemical properties achieved from the measurement of symmetric device demonstrate the ideal capacitive behavior of our prepared electrodes.

  19. Development of an Innovation Model Based on a Service-Oriented Product Service System (PSS

    Directory of Open Access Journals (Sweden)

    Seungkyum Kim

    2015-10-01

    Full Text Available Recently, there have been many attempts to cope with increasingly-diversified and ever-changing customer needs by combining products and services that are critical components of innovation models. Although not only manufacturers, but also service providers, try to integrate products and services, most of the previous studies on Product Service System (PSS development deal with how to effectively integrate services into products from the product-centric point of view. Services provided by manufacturers’ PSSes, such as delivery services, training services, disposal services, and so on, offer customers ancillary value, whereas products of service providers’ PSSes enrich core value by enhancing the functionality and quality of the service. Thus, designing an effective PSS development process from the service-centric point of view is an important research topic. Accordingly, the purpose of this paper is to propose a service-oriented PSS development process, which consists of four stages: (1 strategic planning; (2 idea generation and selection; (3 service design; and (4 product development. In the proposed approach, the PSS development project is initiated and led by a service provider from a service-centric point of view. From the perspective of methodology, customer needs are converted into product functions according to Quality Function Deployment (QFD, while Analytic Hierarchy Process (AHP is employed to prioritize the functions. Additionally, this paper illustrates a service-oriented PSS development that demonstrates the application of the proposed process. The proposed process and illustration are expected to serve as a foundation for research on service-oriented PSS development and as a useful guideline for service providers who are considering the development of a service-oriented PSS.

  20. COMFORT scale: a reliable and valid method to measure the amount of stress of ventilated preterm infants

    NARCIS (Netherlands)

    Wielenga, J. M.; de Vos, R.; de Leeuw, R.; de Haan, R. J.

    2004-01-01

    OBJECTIVE: Assessment of clinimetric properties and diagnostic quality of a stress measurement scale (COMFORT scale). DESIGN: Sample of an open population. SETTING: Neonatology department (Neonatal Intensive Care Unit), Academic Medical Centre/Emma Children's Hospital, Amsterdam, The Netherlands.

  1. Thermal Stress FE Analysis of Large-scale Gas Holder Under Sunshine Temperature Field

    Science.gov (United States)

    Li, Jingyu; Yang, Ranxia; Wang, Hehui

    2018-03-01

    The temperature field and thermal stress of Man type gas holder is simulated by using the theory of sunshine temperature field based on ASHRAE clear-sky model and the finite element method. The distribution of surface temperature and thermal stress of gas holder under the given sunshine condition is obtained. The results show that the thermal stress caused by sunshine can be identified as one of the important factors for the failure of local cracked oil leakage which happens on the sunny side before on the shady side. Therefore, it is of great importance to consider the sunshine thermal load in the stress analysis, design and operation of large-scale steel structures such as the gas holder.

  2. The Arabic Version of The Depression Anxiety Stress Scale-21: Cumulative scaling and discriminant-validation testing.

    Science.gov (United States)

    Ali, Amira Mohammed; Ahmed, Anwar; Sharaf, Amira; Kawakami, Norito; Abdeldayem, Samia M; Green, Joseph

    2017-12-01

    This study aimed to examine the validity of the Arabic version of the Depression Anxiety Stress Scale-21 (DASS-21) in 149 illicit drug users. We calculated α coefficient, inter-item and item-total correlations, coefficients of reproducibility and scalability (CR and CS), item difficulty and discrimination indices. The DASS-21 had an acceptable reliability; but values of the CR and the CS were less than acceptable. Items varied in difficulty and discrimination; some items are candidates for elimination. The DASS-21 is a probabilistic and not a deterministic measure of distress; it has problematic items and needs further investigations. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Depression, Anxiety and Stress Scale in patients with tinnitus and hearing loss.

    Science.gov (United States)

    Gomaa, Mohammed Abdel Motaal; Elmagd, Manal Hassan Abo; Elbadry, Mohammed Mohammed; Kader, Rafeek Mohammed Abdel

    2014-08-01

    The study was proposed to evaluate co-morbid depression, anxiety and stress associated with tinnitus patients. The study was done on 196 subjects: 100 patients suffering from subjective tinnitus associated with hearing loss (tinnitus group), 45 patients suffering from hearing loss only (hearing loss group) and 50 healthy subjects not suffering from tinnitus or hearing loss (control group); the age ranges from 20 to 60 years old. The studied sample was subjected to full ear, nose and throat examinations and audiological evaluation. Depression, Anxiety and Stress Scale (DASS) was developed by Levibond H and Levibond F to assess three self-report scales designed to measure the negative emotional status of depression, anxiety and stress. All patients and control group were evaluated by DASS. (1) Depression: males were affected more than females. All patients over 60 years were affected by depression. The duration of tinnitus seems correlating with the severity of depression. Only 2 patients (4.3 %) of the hearing loss group suffer from depression. (2) Anxiety: 90 % of males suffer from anxiety as compared to 83.3 % females. The age group 20-29 years old suffers more than other age groups. Only 4 patients (8.7 %) of hearing loss group suffer from anxiety. (3) Stress: females seem to be affected by the stress (76.7 %) more than males (67.5). Patients in age group 30-39 suffer the most from the disease. There is a direct correlation between duration of tinnitus and severity of stress. No one of the hearing loss group suffers from stress. In conclusion, depression, anxiety and stress should be taken into consideration in the treatment of patients suffering from tinnitus.

  4. Immobilization of lipases in PSS/PEO blends and applications in esters synthesis

    International Nuclear Information System (INIS)

    Vecchia, Roberto D.; Nascimento, Maria G.; Soldi, Valdir

    2001-01-01

    Various lipases were immobilized in PSS/PEO blends and used as bio catalysts in the esterification reaction of lauric acid with n-pentanol, in hexane as a solvent for 24 h at 35 deg C. The best results in the ester conversion, were obtained by using lipase from Rhryzopus oryzae immobilized in PSS/PEO 80:20 blend. The data are in agreement with DSC and TGA values, which showed that these systems (blend/lipase) were very stable with low mass loss. No product was obtained by using lipase FAP-15 immobilized in PSS film , showing the strong influence of the polymer on enzyme activity. (author)

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

  7. Research on fatigue behavior and residual stress of large-scale cruciform welding joint with groove

    International Nuclear Information System (INIS)

    Zhao, Xiaohui; Liu, Yu; Liu, Yong; Gao, Yuan

    2014-01-01

    Highlights: • The fatigue behavior of the large-scale cruciform welding joint with groove was studied. • The longitudinal residual stress of the large-scale cruciform welding joint was tested by contour method. • The fatigue fracture mechanism of the large-scale cruciform welding joint with groove was analyzed. - Abstract: Fatigue fracture behavior of the 30 mm thick Q460C-Z steel cruciform welded joint with groove was investigated. The fatigue test results indicated that fatigue strength of 30 mm thick Q460C-Z steel cruciform welded joint with groove can reach fatigue level of 80 MPa (FAT80). Fatigue crack source of the failure specimen initiated from weld toe. Meanwhile, the microcrack was also found in the fusion zones of the fatigue failure specimen, which was caused by weld quality and weld metal integrity resulting from the multi-pass welds. Two-dimensional map of the longitudinal residual stress of 30 mm thick Q460C-Z steel cruciform welded joint with groove was obtained by using the contour method. The stress nephogram of Two-dimensional map indicated that longitudinal residual stress in the welding center is the largest

  8. [Two scales for job stress and psychological health investigation: type-A personality and job satisfaction].

    Science.gov (United States)

    Batigün, Ayşegül Durak; Sahin, Nesrin H

    2006-01-01

    The purpose of the present study is to investigate the psychometric properties of two instruments developed to measure Type-A behaviors and job satisfaction, two important variables mentioned in the stress literature. The data were collected from two different samples, one composed of 426 bank personnel, the other composed of 94 adults working in a private company. The findings are presented separately under the titles Study I and Study II. In both of the studies the assessment instruments used were: Stress Audit (Symptoms), Stress Audit (Vulnerability), Stress Coping Behaviors, Job Satisfaction Scale, and Type-A Behaviors Inventory. For both of the instruments, the studies were based on factor analyses. For Type-A Behaviors Inventory the analyses revealed 4 factors, while for Job Satisfaction Scale they revealed 6 factors. The factor subscales developed from these factors were found to have satisfactory Cronbach's alphas. For Type-A Behaviors Inventory they ranged between .40 and .90; whereas for Job Satisfaction Inventory these values were between .53 and .94. Both studies also included correlational analyses to specify the criterion validity values of the two instruments. The findings revealed that both of the instruments had satisfactory psychometric values, indicating that they can be reliably used in health psychology and job stress studies.

  9. [Depression, anxiety and stress scales: DASS--A screening procedure not only for pain patients].

    Science.gov (United States)

    Nilges, P; Essau, C

    2015-12-01

    The assessment of mental distress is a central aspect in pain research and treatment. Particularly for depression the comorbidity with pain poses methodological and conceptual challenges. This study examined the psychometric properties of the short version of the depression, anxiety and stress scale (DASS), used in both pain research and treatment and constructed to overcome the particular problems by omitting somatic items and concentrating on the psychological core aspects of depression, anxiety and stress. The psychometric properties of the DASS-21 were compared between patients with pain and various people without any pain problems (N = 950). The DASS has three subscales, depression, anxiety and stress, each with seven items. The construct validity of the DASS was examined using the hospital anxiety and depression scale (HADS) for anxiety and depression and the general depression scale (Allgemeine Depressionsskala, ADS) for depression. The sensitivity and specificity for depression were determined against a structured interview for diagnostic and statistical manual of mental disorders (DSM-IV) and compared with the Center for Epidemiological Studies depression scale (CESD) and HADS in pain patients. Cronbach's alpha of the DASS for the depression subscale was at least 0.91, while the anxiety and stress subscales had Cronbach alphas of 0.78-0.82 and 0.81-0.89, respectively. Although the depression subscale has only 7 items, it is just as reliable as the ADS with 21 items. It also has a better sensitivity and specificity than the HADS in identifying clinical patients with depression. The DASS is a reliable questionnaire, free to use and brief to administer; therefore, it is an alternative to the previously used instruments for the screening of depression. Furthermore, the subscale stress measures irritability and tension, which are important aspects of pain experience but underused in assessment procedures for the diagnosis and treatment evaluation of patients

  10. The interplay of stress and sleep impacts BDNF level.

    Science.gov (United States)

    Giese, Maria; Unternaehrer, Eva; Brand, Serge; Calabrese, Pasquale; Holsboer-Trachsler, Edith; Eckert, Anne

    2013-01-01

    Sleep plays a pivotal role in normal biological functions. Sleep loss results in higher stress vulnerability and is often found in mental disorders. There is evidence that brain-derived neurotrophic factor (BDNF) could be a central player in this relationship. Recently, we could demonstrate that subjects suffering from current symptoms of insomnia exhibited significantly decreased serum BDNF levels compared with sleep-healthy controls. In accordance with the paradigm indicating a link between sleep and BDNF, we aimed to investigate if the stress system influences the association between sleep and BDNF. Participants with current symptoms of insomnia plus a former diagnosis of Restless Legs Syndrome (RLS) and/or Periodic Limb Movement (PLM) and sleep healthy controls were included in the study. They completed questionnaires on sleep (ISI, Insomnia Severity Index) and stress (PSS, Perceived Stress Scale) and provided a blood sample for determination of serum BDNF. We found a significant interaction between stress and insomnia with an impact on serum BDNF levels. Moreover, insomnia severity groups and score on the PSS each revealed a significant main effect on serum BDNF levels. Insomnia severity was associated with increased stress experience affecting serum BDNF levels. Of note, the association between stress and BDNF was only observed in subjects without insomnia. Using a mediation model, sleep was revealed as a mediator of the association between stress experience and serum BDNF levels. This is the first study to show that the interplay between stress and sleep impacts BDNF levels, suggesting an important role of this relationship in the pathogenesis of stress-associated mental disorders. Hence, we suggest sleep as a key mediator at the connection between stress and BDNF. Whether sleep is maintained or disturbed might explain why some individuals are able to handle a certain stress load while others develop a mental disorder.

  11. The interplay of stress and sleep impacts BDNF level.

    Directory of Open Access Journals (Sweden)

    Maria Giese

    Full Text Available BACKGROUND: Sleep plays a pivotal role in normal biological functions. Sleep loss results in higher stress vulnerability and is often found in mental disorders. There is evidence that brain-derived neurotrophic factor (BDNF could be a central player in this relationship. Recently, we could demonstrate that subjects suffering from current symptoms of insomnia exhibited significantly decreased serum BDNF levels compared with sleep-healthy controls. In accordance with the paradigm indicating a link between sleep and BDNF, we aimed to investigate if the stress system influences the association between sleep and BDNF. METHODOLOGY/PRINCIPAL FINDINGS: Participants with current symptoms of insomnia plus a former diagnosis of Restless Legs Syndrome (RLS and/or Periodic Limb Movement (PLM and sleep healthy controls were included in the study. They completed questionnaires on sleep (ISI, Insomnia Severity Index and stress (PSS, Perceived Stress Scale and provided a blood sample for determination of serum BDNF. We found a significant interaction between stress and insomnia with an impact on serum BDNF levels. Moreover, insomnia severity groups and score on the PSS each revealed a significant main effect on serum BDNF levels. Insomnia severity was associated with increased stress experience affecting serum BDNF levels. Of note, the association between stress and BDNF was only observed in subjects without insomnia. Using a mediation model, sleep was revealed as a mediator of the association between stress experience and serum BDNF levels. CONCLUSIONS: This is the first study to show that the interplay between stress and sleep impacts BDNF levels, suggesting an important role of this relationship in the pathogenesis of stress-associated mental disorders. Hence, we suggest sleep as a key mediator at the connection between stress and BDNF. Whether sleep is maintained or disturbed might explain why some individuals are able to handle a certain stress load while

  12. Reliability and validity analysis of modified Nursing Stress Scale for Indian population.

    Science.gov (United States)

    Pathak, Vasundhara; Chakraborty, Tania; Mukhopadhyay, Suman

    2013-01-01

    The original Nursing Stress Scale (NSS) was structurally modified according to results of factorial analysis and a new scale was named as modified nursing stress scale (MNSS). This is the first study to modify and validate NSS for Indian nursing population. Factorial analysis showed different factor loading for two subscales and items were shifted according to their loading to provide a more meaningful structure. After relocation of Items 13, 14, and 15 into first factor, this factor was renamed as "emotional and painful conditions of patients" to provide a more appropriate name to the first factor. Items 24, 25, 26, 27, 28, and 29 were found to be distributed under two different factors; one of these two was renamed as "unpredictable changes" and another retained its original name (i.e., workload). This distribution was also supported by rational analysis. All other items were distributed under factors as in the original scale. Rest of the validity assessment was done with the modified scale. Thus, with minor changes in structure, the scale was found to have better content validity.

  13. Nanoscale Roughness of Faults Explained by the Scale-Dependent Yield Stress of Geologic Materials

    Science.gov (United States)

    Thom, C.; Brodsky, E. E.; Carpick, R. W.; Goldsby, D. L.; Pharr, G.; Oliver, W.

    2017-12-01

    Despite significant differences in their lithologies and slip histories, natural fault surfaces exhibit remarkably similar scale-dependent roughness over lateral length scales spanning 7 orders of magnitude, from microns to tens of meters. Recent work has suggested that a scale-dependent yield stress may result in such a characteristic roughness, but experimental evidence in favor of this hypothesis has been lacking. We employ an atomic force microscope (AFM) operating in intermittent-contact mode to map the topography of the Corona Heights fault surface. Our experiments demonstrate that the Corona Heights fault exhibits isotropic self-affine roughness with a Hurst exponent of 0.75 +/- 0.05 at all wavelengths from 60 nm to 10 μm. If yield stress controls roughness, then the roughness data predict that yield strength varies with length scale as λ-0.25 +/ 0.05. To test the relationship between roughness and yield stress, we conducted nanoindentation tests on the same Corona Heights sample and a sample of the Yair Fault, a carbonate fault surface that has been previously characterized by AFM. A diamond Berkovich indenter tip was used to indent the samples at a nominally constant strain rate (defined as the loading rate divided by the load) of 0.2 s-1. The continuous stiffness method (CSM) was used to measure the indentation hardness (which is proportional to yield stress) and the elastic modulus of the sample as a function of depth in each test. For both samples, the yield stress decreases with increasing size of the indents, a behavior consistent with that observed for many engineering materials and recently for other geologic materials such as olivine. The magnitude of this "indentation size effect" is best described by a power-law with exponents of -0.12 +/- 0.06 and -0.18 +/- 0.08 for the Corona Heights and Yair Faults, respectively. These results demonstrate a link between surface roughness and yield stress, and suggest that fault geometry is the physical

  14. Discriminating Malingered from Genuine Civilian Posttraumatic Stress Disorder: A Validation of Three MMPI-2 Infrequency Scales (F, Fp, and Fptsd)

    Science.gov (United States)

    Elhai, Jon D.; Naifeh, James A.; Zucker, Irene S.; Gold, Steven N.; Deitsch, Sarah E.; Frueh, B. Christopher

    2004-01-01

    The Infrequency-Posttraumatic Stress Disorder scale (Fptsd), recently created for the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), has demonstrated incremental validity over other MMPI-2 scales in malingered posttraumatic stress disorder (PTSD) detection. Fptsd was developed with combat-exposed PTSD patients, potentially limiting its…

  15. Nonvolatile write-once-read-many-times memory device with functionalized-nanoshells/PEDOT:PSS nanocomposites

    International Nuclear Information System (INIS)

    Avila-Nino, J.A.; Segura-Cardenas, E.; Sustaita, A.O.; Cruz-Cruz, I.; Lopez-Sandoval, R.; Reyes-Reyes, M.

    2011-01-01

    We have investigated the memory effect of the nanocomposites of functionalized carbon nanoshells (f-CNSs) mixed with poly(3,4-ethylenedioxythiophene) doped with polystyrenesulfonate (PEDOT:PSS) polymer. The f-CNSs were synthesized by the spray pyrolysis method and functionalized in situ with functional groups (OH, COOH, C-H, C-OH) with the aim of improving their compatibility in the aqueous dispersion of PEDOT:PSS. The current-voltage (I-V) sweep curves at room temperature for the Al/f-CNSs, for certain concentrations range, embedded in a PEDOT:PSS layer/Al devices showed electrical bistability for write-once-read-many-times (WORM) memory devices. The memory effect observed in the devices can be explained due to the existence of trapped charges in the f-CNSs/PEDOT:PSS layer. The carrier transport mechanisms for the memory devices is studied and discussed.

  16. Nonvolatile write-once-read-many-times memory device with functionalized-nanoshells/PEDOT:PSS nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Avila-Nino, J.A.; Segura-Cardenas, E. [Universidad Autonoma de San Luis Potosi, Instituto de Investigacion en Comunicacion Optica, Alvaro Obregon 64 Zona Centro, 78000 SLP (Mexico); Sustaita, A.O. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216, San Luis Potosi (Mexico); Cruz-Cruz, I. [Universidad Autonoma de San Luis Potosi, Instituto de Investigacion en Comunicacion Optica, Alvaro Obregon 64 Zona Centro, 78000 SLP (Mexico); Lopez-Sandoval, R. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216, San Luis Potosi (Mexico); Reyes-Reyes, M., E-mail: reyesm@iico.uaslp.mx [Universidad Autonoma de San Luis Potosi, Instituto de Investigacion en Comunicacion Optica, Alvaro Obregon 64 Zona Centro, 78000 SLP (Mexico)

    2011-03-25

    We have investigated the memory effect of the nanocomposites of functionalized carbon nanoshells (f-CNSs) mixed with poly(3,4-ethylenedioxythiophene) doped with polystyrenesulfonate (PEDOT:PSS) polymer. The f-CNSs were synthesized by the spray pyrolysis method and functionalized in situ with functional groups (OH, COOH, C-H, C-OH) with the aim of improving their compatibility in the aqueous dispersion of PEDOT:PSS. The current-voltage (I-V) sweep curves at room temperature for the Al/f-CNSs, for certain concentrations range, embedded in a PEDOT:PSS layer/Al devices showed electrical bistability for write-once-read-many-times (WORM) memory devices. The memory effect observed in the devices can be explained due to the existence of trapped charges in the f-CNSs/PEDOT:PSS layer. The carrier transport mechanisms for the memory devices is studied and discussed.

  17. Charge injection and accumulation in organic light-emitting diode with PEDOT:PSS anode

    Energy Technology Data Exchange (ETDEWEB)

    Weis, Martin, E-mail: martin.weis@stuba.sk [Institute of Electronics and Photonics, Slovak University of Technology, Ilkovičova 3, Bratislava 81219 (Slovakia); Otsuka, Takako; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@ome.pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2015-04-21

    Organic light-emitting diode (OLED) displays using flexible substrates have many attractive features. Since transparent conductive oxides do not fit the requirements of flexible devices, conductive polymer poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) has been proposed as an alternative. The charge injection and accumulation in OLED devices with PEDOT:PSS anodes are investigated and compared with indium tin oxide anode devices. Higher current density and electroluminescence light intensity are achieved for the OLED device with a PEDOT:PSS anode. The electric field induced second-harmonic generation technique is used for direct observation of temporal evolution of electric fields. It is clearly demonstrated that the improvement in the device performance of the OLED device with a PEDOT:PSS anode is associated with the smooth charge injection and accumulation.

  18. Microtexturing of the conductive PEDOT:PSS Polymer for superhydrophobic organic electrochemical transistors

    KAUST Repository

    Gentile, Francesco; Coppedè , Nicola; Tarabella, Giuseppe; Villani, Marco; Calestani, Davide; Candeloro, Patrizio; Iannotta, Salvatore; Di Fabrizio, Enzo M.

    2014-01-01

    and materials science to obtain an advanced device where, on account of the superhydrophobicity of the system, the solutions of interest can be manipulated and, on account of the conductive PEDOT:PSS polymer, the charged molecules dispersed inside can

  19. Tailoring the Electrochemical and Mechanical Properties of PEDOT:PSS Films for Bioelectronics

    KAUST Repository

    Elmahmoudy, Mohammed; Inal, Sahika; Charrier, Anne; Uguz, Ilke; Malliaras, George G.; Sanaur, Sé bastien

    2017-01-01

    The effect of 3-glycidoxypropyltrimethoxysilane (GOPS) content in poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) dispersions on the properties of films spun cast from these formulations is investigated. It has been found out

  20. Relationship between depression anxiety stress scale (DASS) and urinary hydroxyproline and proline concentrations in hospital workers.

    Science.gov (United States)

    Lee, Keou Won; Kim, Soo Jeong; Park, Jae Beom; Lee, Kyung Jong

    2011-01-01

    Although increased reactive oxygen species (ROS) is caused by stress accelerates collagen degradation, there was no data on the relationship between stress and urinary hydroxyproline (Hyp) and proline (Pro), a good marker of collagen degradation. The purpose of this study was to evaluate the relationship between depression, anxiety, and stress (DAS) and concentrations of urinary Hyp and Pro. 97 hospital employees aged 20 to 58 were asked to fill out comprehensive self-administrated questionnaires containing information about their medical history, lifestyle, length of the work year, shift-work and DAS. depression anxiety stress scale (DASS) was applied to evaluate chronic mental disorders. Urine samples were analyzed using high performance liquid chromatography (HPLC) with double derivatization for the assay of hydroxyproline and proline. The mean value of Hyp and Pro concentration in all subjects was 194.1 ± 113.4 μmol/g and 568.2 ± 310.7 μmol/g. DASS values and urinary Pro concentrations were differentiated by sex (female > male, p others, p < 0.05). In the stepwise multiple linear regressions, urinary Hyp and Pro concentrations were influenced by stress (Adjusted r2 = 0.051) and anxiety and job (Adjusted r2 = 0.199), respectively. We found that stress and anxiety were correlated with urinary Hyp and Pro concentrations. To identifying a definite correlation, further study in large populations will be needed.

  1. Reliability and validity of the Perceived Stress Scale-10 in Hispanic Americans with English or Spanish language preference.

    Science.gov (United States)

    Baik, Sharon H; Fox, Rina S; Mills, Sarah D; Roesch, Scott C; Sadler, Georgia Robins; Klonoff, Elizabeth A; Malcarne, Vanessa L

    2017-01-01

    This study examined the psychometric properties of the Perceived Stress Scale-10 among 436 community-dwelling Hispanic Americans with English or Spanish language preference. Multigroup confirmatory factor analysis examined the factorial invariance of the Perceived Stress Scale-10 across language groups. Results supported a two-factor model (negative, positive) with equivalent response patterns and item intercepts but different factor covariances across languages. Internal consistency reliability of the Perceived Stress Scale-10 total and subscale scores was good in both language groups. Convergent validity was supported by expected relationships of Perceived Stress Scale-10 scores to measures of anxiety and depression. These results support the use of the Perceived Stress Scale-10 among Hispanic Americans.

  2. Towards a Lean Product Service Systems (PSS) Design: State of the Art, Opportunities and Challenges

    OpenAIRE

    Sassanelli, Claudio; Pezzotta, Giuditta; Rossi, Monica; Terzi, Sergio; Cavalieri, Sergio

    2015-01-01

    As for conventional products, the profit generation and the market success of Product Service Systems (PSS) critically depend on the decisions taken during the initial lifecycle stages, when PSSs are conceptualized, designed, developed and engineered. Successful cases show the adoption of lean techniques in the early stages of products development, impelling the authors to assess the application of the same approaches also to PSS development. For this reasons the paper aims to report the stat...

  3. Residual stress measurement of large scaled welded pipe using neutron diffraction method. Effect of SCC crack propagation and repair weld on residual stress distribution

    International Nuclear Information System (INIS)

    Suzuki, Hiroshi; Katsuyama, Jinya; Tobita, Tohru; Morii, Yukio

    2011-01-01

    The RESA-1 neutron engineering diffractometer in the JRR-3 (Japan Research Reactor No.3) at the Japan Atomic Energy Agency, which is used for stress measurements, was upgraded to realize residual stress measurements of large scaled mechanical components. A series of residual stress measurements was made to obtain through-thickness residual stress distributions in a Type 304 stainless steel butt-welded pipe of 500A-sch.80 using the upgraded RESA-1 diffractometer. We evaluated effects of crack propagation such as stress corrosion cracking (SCC) and a part-circumference repair weld on the residual stress distributions induced by girth welding. Measured residual stress distributions near original girth weld revealed good agreement with typical results shown in some previous works using finite element method, deep hole drilling as well as neutron diffraction. After introducing a mock crack with 10 mm depth in the heat affected zone on the inside wall of the pipe by electro discharge machining, the axial residual stresses were found to be released in the part of the mock crack. However, changes in the through-wall bending stress component and the self-equilibrated stress component were negligible and hence the axial residual stress distribution in the ligament was remained in the original residual stresses near girth weld without the mock crack. Furthermore, changes in hoop and radial residual stress were also small. The residual stress distributions after a part repair welding on the outer circumference of the girth weld were significantly different from residual stress distributions near the original girth weld. The through-thickness average axial residual stress was increased due to increase of the tensile membrane stress and mitigation of the bending stress after repair welding. Throughout above studies, we evidenced that the neutron diffraction technique is useful and powerful tool for measuring residual stress distributions in large as well as thick mechanical

  4. Comparison of intelligent fuzzy based AGC coordinated PID controlled and PSS controlled AVR system

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, V. [Department of Electrical Engineering, Asansol Engineering College, Asansol, West Bengal (India); Ghoshal, S.P. [Department of Electrical Engineering, National Institute of Technology, Durgapur, West Bengal (India)

    2007-11-15

    This paper attempts to investigate the performance of intelligent fuzzy based coordinated control of the Automatic Generation Control (AGC) loop and the excitation loop equipped with Proportional Integral Derivative (PID) controlled Automatic Voltage Regulator (AVR) system and Power System Stabilizer (PSS) controlled AVR system. The work establishes that PSS controlled AVR system is much more robust in dynamic performance of the system over a wide range of system operating configurations. Thus, it is revealed that PSS equipped AVR is much more superior than PID equipped AVR in damping the oscillation resulting in improved transient response. The paper utilizes a novel class of Particle Swarm Optimization (PSO) termed as Craziness based Particle Swarm Optimization (CRPSO) as optimizing tool to get optimal tuning of PSS parameters as well as the gains of PID controllers. For on-line, off-nominal operating conditions Takagi Sugeno Fuzzy Logic (TSFL) has been applied to obtain the off-nominal optimal gains of PID controllers and parameters of PSS. Implementation of TSFL helps to achieve very fast dynamic response. Fourth order model of generator with AVR and high gain thyristor excitation system is considered for PSS controlled system while normal gain exciter is considered for PID controlled system. Simulation study also reveals that with high gain exciter, PID control is not at all effective. Transient responses are achieved by using modal analysis. (author)

  5. Genome-scale cold stress response regulatory networks in ten Arabidopsis thaliana ecotypes

    DEFF Research Database (Denmark)

    Barah, Pankaj; Jayavelu, Naresh Doni; Rasmussen, Simon

    2013-01-01

    available from Arabidopsis thaliana 1001 genome project, we further investigated sequence polymorphisms in the core cold stress regulon genes. Significant numbers of non-synonymous amino acid changes were observed in the coding region of the CBF regulon genes. Considering the limited knowledge about......BACKGROUND: Low temperature leads to major crop losses every year. Although several studies have been conducted focusing on diversity of cold tolerance level in multiple phenotypically divergent Arabidopsis thaliana (A. thaliana) ecotypes, genome-scale molecular understanding is still lacking....... RESULTS: In this study, we report genome-scale transcript response diversity of 10 A. thaliana ecotypes originating from different geographical locations to non-freezing cold stress (10°C). To analyze the transcriptional response diversity, we initially compared transcriptome changes in all 10 ecotypes...

  6. Depression Anxiety and Stress Scales (DASS-21): psychometric analysis across four racial groups.

    Science.gov (United States)

    Norton, Peter J

    2007-09-01

    Growing cross-cultural awareness has led researchers to examine frequently used research instruments and assessment tools in racially diverse populations. The present study was conducted to assess the psychometric characteristics of the 21-item version of the Depression, Anxiety, and Stress Scales (DASS-21) among different racial groups. The DASS-21 was chosen because it appears to be a reliable and easy to administer measure, ideal for both clinical and research purposes. Results suggest that the internal consistency, and convergent and divergent validity of the DASS-21 are similar across racial groups. Multigroup CFA, however, indicated that item loadings were invariant, while scale covariances were not invariant. This suggests that, although the items may load similarly on the depression, anxiety and stress constructs, these constructs may be differentially inter-related across groups. Implications for application in clinical practice are discussed.

  7. Depression Anxiety Stress Scale: is it valid for children and adolescents?

    Science.gov (United States)

    Patrick, Jeff; Dyck, Murray; Bramston, Paul

    2010-09-01

    The Depression Anxiety Stress Scale (Lovibond & Lovibond, 1995) is used to assess the severity of symptoms in child and adolescent samples although its validity in these populations has not been demonstrated. The authors assessed the latent structure of the 21-item version of the scale in samples of 425 and 285 children and adolescents on two occasions, one year apart. On each occasion, parallel analyses suggested that only one component should be extracted, indicating that the test does not differentiate depression, anxiety, and stress in children and adolescents. The results provide additional evidence that adult models of depression do not describe the experience of depression in children and adolescents. (c) 2010 Wiley Periodicals, Inc.

  8. Psychometric properties and validation of Nepali version of the Depression Anxiety Stress Scales (DASS-21).

    Science.gov (United States)

    Tonsing, Kareen N

    2014-04-01

    This study investigated the reliability of the Nepali version of the 21-item Depression Anxiety Stress Scale (DASS-21) among non-clinical sample. The purpose of this paper is to report the dimensionality and internal consistency of the DASS-21in a sample of non-clinical adults. This study was conducted in Hong Kong among 212 Nepali adults, aged 18-60 years. Life satisfaction was assessed with the Life Satisfaction Scale. The dimensionality of the DASS-21 scale was investigated using exploratory factor analysis. Construct validity was evaluated using the life satisfaction scale. The intercorrelation among depression, anxiety and stress subscales indicates that symptoms of psychological distress as measured by the DASS-21-N can distinguished between the three constructs in adult community sample. The results also showed inverse correlation among DASS-21-N and life satisfaction scale, supporting the assumption that the higher the life satisfaction, the lower the psychological distress. The results of this study indicate that the Nepali version of the DASS-21 demonstrate adequate psychometric properties in relation to internal consistency and validity, lending support to prior studies and suggest that the DASS-21 can be utilized among diverse groups with confidence. It supports the reliability of the 3-factorial dimensionality of the DASS-21, and highlight that it is a valid and useful tool that can distinguish between depression and anxiety. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. High Mobility, Hole Transport Materials for Highly Efficient PEDOT:PSS Replacement in Inverted Perovskite Solar Cells

    KAUST Repository

    Neophytou, Marios

    2017-04-24

    Perovskite solar cells are one of the most promising photovoltaic technologies, due to their rapid increase in power conversion efficiency (3.8% to 21.1%) in a very short period of time and the relative ease of their fabrication compared to traditional inorganic solar cells. One of the drawbacks of perovskite solar cells is their limited stability in non-inert atmospheres. In the inverted device configuration this lack of stability can be attributed to the inclusion of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate(PEDOT:PSS) as the hole transporting layer. Herein we report the synthesis of two new triarylamine based hole transporting materials, synthesised from readily available starting materials. These new materials show increased power conversion efficiencies, of 13.0% and 12.1%, compared to PEDOT:PSS (10.9%) and exhibit increased stability achieving lifetimes in excess of 500 hours. Both molecules are solution processible at low temperatures and offer potential for low cost, scalable production on flexible substrates for large scale perovskite solar cells.

  10. High Mobility, Hole Transport Materials for Highly Efficient PEDOT:PSS Replacement in Inverted Perovskite Solar Cells

    KAUST Repository

    Neophytou, Marios; Griffiths, Jack; Fraser, James; Kirkus, Mindaugas; Chen, Hu; Nielsen, Christian; McCulloch, Iain

    2017-01-01

    Perovskite solar cells are one of the most promising photovoltaic technologies, due to their rapid increase in power conversion efficiency (3.8% to 21.1%) in a very short period of time and the relative ease of their fabrication compared to traditional inorganic solar cells. One of the drawbacks of perovskite solar cells is their limited stability in non-inert atmospheres. In the inverted device configuration this lack of stability can be attributed to the inclusion of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate(PEDOT:PSS) as the hole transporting layer. Herein we report the synthesis of two new triarylamine based hole transporting materials, synthesised from readily available starting materials. These new materials show increased power conversion efficiencies, of 13.0% and 12.1%, compared to PEDOT:PSS (10.9%) and exhibit increased stability achieving lifetimes in excess of 500 hours. Both molecules are solution processible at low temperatures and offer potential for low cost, scalable production on flexible substrates for large scale perovskite solar cells.

  11. Time-variable stress transfer across a megathrust from seismic to Wilson cycle scale

    Science.gov (United States)

    Rosenau, Matthias; Angiboust, Samuel; Moreno, Marcos; Schurr, Bernd; Oncken, Onno

    2013-04-01

    During the lifetime of a convergent plate margin stress transfer across the plate interface (a megathrust) can be expected to vary at multiple timescales. At short time scales (years to decades), a subduction megathrust interface appears coupled (accumulating shear stress) at shallow depth (seismogenic zone proportional to effective normal load but also to relative shear stress. For areas of near complete stress drop locking might systematically decrease over the interseismic period from >80-95 % shortly after an earthquake to backslip at significant fractions of plate convergence rate (non-volcanic tremor and slow slip below the seismogenic zone represent short term episodes of metamorphic fluid infiltration into the shallow megathrust. A megathrust fault valve mechanism clocked by the greatest earthquakes then accounts for cyclic fluid pressure build up and drainage at sub-seismic cycle scale. As pore pressure dynamics are controlled primarily by permeability which in turn is controlled by structure and material properties, then more long term coupling transients associated with structural evolution of the plate margin can be implied. Fluid controlled transients might interfere with transients and secular trends resulting from changes in material strength and plate tectonic forces over the Wilson cycle resulting in a multispectral stress-transfer pattern associated with convergent margin evolution. Because of the viscous damping effect of the underlying asthenosphere, however, only longterm transients (periods >1-10 ka) are transmitted into the engaged plates. We therefore speculate that the multispectral nature of stress transfer across a megathrust filtered through the asthenosphere explains transient fault activity in some intraplate settings.

  12. The relationship between event-related potentials, stress perception and personality type in patients with multiple sclerosis without cognitive impairment: A pilot study.

    Science.gov (United States)

    Waliszewska-Prosół, Marta; Nowakowska-Kotas, Marta; Kotas, Roman; Bańkowski, Tomasz; Pokryszko-Dragan, Anna; Podemski, Ryszard

    2018-06-08

    The clinical course of multiple sclerosis (MS) can vary significantly among patients and is affected by exogenous and endogenous factors. Among these, stress and personality type have been gaining more attention. The aim of this study was to investigate the parameters of event-related potentials (ERPs) with regards to stress perception and personality type, as well as cognitive performance in MS patients. The study group consisted of 30 MS patients and 26 healthy controls. Auditory ERPs were performed in both groups, including an analysis of P300 and N200 response parameters. The Perceived Stress Scale (PSS) was used in the MS group to measure the perception of stress. The D-type Scale (DS14) scale was used to determine the features of Type D personality, characterized by social inhibition and negative affectivity. The score on the PSS corresponded with a moderate or high level of stress perception in 63% of MS patients, while 23% of patients presented with a Type D personality. P300 latencies were significantly longer (p = 0.001), N200 amplitudes were significantly higher (p = 0.004), and N200 latencies were longer in MS patients than in the controls. Strong positive correlations were found between N200 and P300 amplitudes, as well as between the DS14 and PSS results. Most MS patients experience moderate to severe stress. ERP abnormalities were found in MS patients who did not have overt cognitive impairment and showed correlations with stress levels and negative affectivity. Event-related potentials may be useful in assessing the influence of stress and emotions on the course of MS.

  13. Energy and Environmental Drivers of Stress and Conflict in Multi scale Models of Human Social Behavior

    Science.gov (United States)

    2017-10-31

    resolved by the recognition that cities are first and foremost self- organizing social networks embedded in space and enabled by urban infrastructure and...AUTHORS 7. PERFORMING ORGANIZATION NAMES AND ADDRESSES 15. SUBJECT TERMS b. ABSTRACT 2. REPORT TYPE 17. LIMITATION OF ABSTRACT 15. NUMBER OF PAGES 5d...Report: Energy and Environmental Drivers of Stress and Conflict in Multi-scale Models of Human Social Behavior The views, opinions and/or findings

  14. Adaptation and validation of the depression, anxiety and stress scale (DASS) to Brazilian Portuguese.

    Science.gov (United States)

    Vignola, Rose Claudia Batistelli; Tucci, Adriana Marcassa

    2014-02-01

    Depression and anxiety have been associated with a range of symptoms that often overlap. Depression, Anxiety and Stress Scale-21 (DASS-21) is a single instrument to assess symptoms of depression, anxiety and stress. This study aimed to adapt and validate the DASS-21 for use in the Brazilian Portuguese language. The DASS-21 has been adapted following the translation-back translation methodology from English to Portuguese. 242 subjects completed the following assessments: the DASS-21, the Beck Depression Index (BDI), Beck Anxiety Index (BAI) and the Inventory of Stress Symptoms of Lipp (ISSL). The Kaiser-Meyer-Olkin (KMO) result was .949, indicating that the adequacy of the model was high. Cronbach's alpha was .92 for the depression, .90 for the stress, and .86 for the anxiety, indicating a good internal consistency for each subscale. The correlations between DASS scale and BDI scale, BAI scale and ISSL inventory were strong. The factorial analysis and distribution of factors among the subscales indicated that the structure of three distinct factors is adequate. Older subjects over 65 years of age were not largely represented in this sample. A study specific to this elderly population should be conducted. Another limitation of the study was education level. The impact of low education in its applicability should be considered. The findings support the validity of the Brazilian Portuguese version of the DASS-21 and add to the evidence of the DASS-21 quality and ability to assess emotional states separately, eliminating the use of different instruments to assess these states. © 2013 Published by Elsevier B.V.

  15. Psychometric evaluation of the Nursing Stress Scale (NSS) among Chinese nurses in Taiwan.

    Science.gov (United States)

    Lee, Mei-Hua; Holzemer, William L; Faucett, Julia

    2007-01-01

    The purpose of this study was to translate the Nursing Stress Scale (NSS) into Chinese and test its reliability and validity among Chinese nurses in Taiwan. Potential participants were asked to self-administer a Chinese version of the NSS. The agreement estimation was used to determine the equivalence of the meaning between the Chinese and original English versions and was rated by five bilingual nurses as 92% accurate for the 34 items. The test-retest reliability for the NSS at 2 weeks was .71 (p = .022, n=10). Internal consistency reliability and factor analysis were tested with 770 nurses from 65 inpatient units at a medical center in Taiwan. The internal consistency of the Chinese version of the NSS for an overall coefficient alpha is .91 for the total scale, and ranges from .67 to .79 for the subscales. The Chinese version of the NSS explains 53.77% of the variance in work stressors among Chinese nurses in Taiwan. Overall, the Chinese version of the NSS is internally consistent but may not be stable over 2 weeks. There was adequate evidence of the reliability and validity of the NSS-Chinese as an instrument appropriate to measure work stress among Chinese nurses. The translated NSS could be a useful tool for examining the frequency and major sources of stress experienced by Chinese nurses in hospital settings, and for the development of appropriate interventions for stress reduction.

  16. Development of the Seasonal Migrant Agricultural Worker Stress Scale in Sanliurfa, Southeast Turkey.

    Science.gov (United States)

    Simsek, Zeynep; Ersin, Fatma; Kirmizitoprak, Evin

    2016-01-01

    Stress is one of the main causes of health problems, especially mental disorders. These health problems cause a significant amount of ability loss and increase cost. It is estimated that by 2020, mental disorders will constitute 15% of the total disease burden, and depression will rank second only after ischemic heart disease. Environmental experiences are paramount in increasing the liability of mental disorders in those who constantly face sustained high levels of stress. The objective of this study was to develop a stress scale for seasonal migrant agricultural workers aged 18 years and older. The sample consisted of 270 randomly selected seasonal migrant agricultural workers. The average age of the participants was 33.1 ± 14, and 50.7% were male. The Cronbach alpha coefficient and test-retest methods were used for reliability analyses. Although the factor analysis was performed for the structure validity of the scale, the Kaiser-Meyer-Olkin coefficient and Bartlett test were used to determine the convenience of the data for the factor analysis. In the reliability analyses, the Cronbach alpha coefficient of internal consistency was calculated as .96, and the test-retest reliability coefficient was .81. In the exploratory factor analysis for validity of the scale, four factors were obtained, and the factors represented workplace physical conditions (25.7% of the total variance), workplace psychosocial and economic factors (19.3% of the total variance), workplace health problems (15.2% of the total variance), and school problems (10.1% of the total variance). The four factors explained 70.3% of the total variance. As a result of the expert opinions and analyses, a stress scale with 48 items was developed. The highest score to be obtained from the scale was 144, and the lowest score was 0. The increase in the score indicates the increase in the stress levels. The findings show that the scale is a valid and reliable assessment instrument that can be used in

  17. Exercise Maintains Dendritic Complexity in an Animal Model of Posttraumatic Stress Disorder.

    Science.gov (United States)

    Hoffman, Jay R; Cohen, Hadas; Ostfeld, Ishay; Kaplan, Zeev; Zohar, Joseph; Cohen, Hagit

    2016-12-01

    This study examined the effect of endurance exercise on dendritic arborization in the dentate gyrus subregion in rodents exposed to a predator scent stress (PSS). Sprague-Dawley rats were randomly assigned to one of four treatment groups. In two of the groups, rats were unexposed to PSS but either remained sedentary (SED + UNEXP) or were exercised (EX + UNEXP). In the other two groups, rats were exposed to the PSS but either remained sedentary (SED + PSS) or were exercised (EX + PSS). After 6 wk of either exercise or sedentary lifestyle, rats were exposed to either the PSS or a sham protocol. During exercise, the animals ran on a treadmill at 15 m·min, 5 min·d gradually increasing to 20 min·d, 5 d·wk for 6 wk. Eight days after exposure to either PSS or sham protocol, changes in the cytoarchitecture (dendritic number, dendritic length, and dendrite spine density) of the dentate gyrus subregion of the hippocampus were assessed. No differences (P = 0.493) were noted in dendritic number between the groups. However, dendritic length and dendrite spine density for SED + PSS was significantly smaller (P animals in SED + PSS had significantly fewer (P stress. This provides further evidence for supporting the inclusion of an exercise regimen for reducing the risk of posttraumatic stress disorder.

  18. Large scale structures in a turbulent boundary layer and their imprint on wall shear stress

    Science.gov (United States)

    Pabon, Rommel; Barnard, Casey; Ukeiley, Lawrence; Sheplak, Mark

    2015-11-01

    Experiments were performed on a turbulent boundary layer developing on a flat plate model under zero pressure gradient flow. A MEMS differential capacitive shear stress sensor with a 1 mm × 1 mm floating element was used to capture the fluctuating wall shear stress simultaneously with streamwise velocity measurements from a hot-wire anemometer traversed in the wall normal direction. Near the wall, the peak in the cross correlation corresponds to an organized motion inclined 45° from the wall. In the outer region, the peak diminishes in value, but is still significant at a distance greater than half the boundary layer thickness, and corresponds to a structure inclined 14° from the wall. High coherence between the two signals was found for the low-frequency content, reinforcing the belief that large scale structures have a vital impact on wall shear stress. Thus, estimation of the wall shear stress from the low-frequency velocity signal will be performed, and is expected to be statistically significant in the outer boundary layer. Additionally, conditionally averaged mean velocity profiles will be presented to assess the effects of high and low shear stress. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1315138.

  19. Wafer scale lead zirconate titanate film preparation by sol-gel method using stress balance layer

    International Nuclear Information System (INIS)

    Lu Jian; Kobayashi, Takeshi; Yi Zhang; Maeda, Ryutaro; Mihara, Takashi

    2006-01-01

    In this paper, platinum/titanium (Pt/Ti) film was introduced as a residual stress balance layer into wafer scale thick lead zirconate titanate (PZT) film fabrication by sol-gel method. The stress developing in PZT film's bottom electrode as well as in PZT film itself during deposition were analyzed; the wafer curvatures, PZT crystallizations and PZT electric properties before and after using Pt/Ti stress balance layer were studied and compared. It was found that this layer is effective to balance the residual stress in PZT film's bottom electrode induced by thermal expansion coefficient mismatch and Ti diffusion, thus can notably reduce the curvature of 4-in. wafer from - 40.5 μm to - 12.9 μm after PZT film deposition. This stress balance layer was also found effective to avoid the PZT film cracking even when annealed by rapid thermal annealing with heating-rate up to 10.5 deg. C/s. According to X-ray diffraction analysis and electric properties characterization, crack-free uniform 1-μm-thick PZT film with preferred pervoskite (001) orientation, excellent dielectric constant, as high as 1310, and excellent remanent polarization, as high as 39.8 μC/cm 2 , can be obtained on 4-in. wafer

  20. A cross-country comparative study on stress and quality of life in nursing students.

    Science.gov (United States)

    Labrague, Leodoro J; McEnroe-Petitte, Denise M; Papathanasiou, Ioanna V; Edet, Olaide B; Tsaras, Konstantinos; Christos, Kleisiaris F; Fradelos, Evangelos C; Rosales, Rheajane A; Cruz, Jonas P; Leocadio, Michael; Lucas, Katherine Vera S

    2017-10-27

    This study was conducted to compare perceptions of stress and quality of life (QoL) among nursing students from three countries (the Philippines, Greece, and Nigeria) and to examine the impact of stress on their QoL. A comparative, cross-sectional research design was used in this study. Data were collected from 547 nursing students from three countries using the perceived stress scale (PSS) and the quality of life evaluation skill (QOLES). Students' perceptions of stress and QoL were different across the three countries. Furthermore, higher stress perceptions were identified from taking care of patients, the clinical environment, and faculty, peer, and staff encounters, which predicted a negative QoL. The findings emphasized the need for empirically tested and culturally tailored interventions to effectively reduce stress and enhance the QoL in nursing students. © 2017 Wiley Periodicals, Inc.

  1. Factor structure and validity of the Depression, Anxiety and Stress Scale-21 in Swedish translation.

    Science.gov (United States)

    Alfonsson, S; Wallin, E; Maathz, P

    2017-03-01

    WHAT IS KNOWN ON THE SUBJECT?: The Depression, Anxiety and Stress Scale-21 (DASS-21) is a widely used measurement for psychological symptoms and distress. Some previous studies have shown that the DASS-21 can accurately measure symptoms of anxiety, depression and stress, while other studies have indicated that the DASS-21 mainly measures overall distress. The factor structure of the DASS-21 is important and debated since if affects interpretations of findings. WHAT DOES THIS PAPER ADD TO EXISTING KNOWLEDGE?: In this study, the DASS-21 was translated into Swedish and evaluated in three diverse samples. The DASS-21 subscales of Depression and Anxiety correlated significantly with corresponding criteria instruments. The DASS-21 Stress subscale showed more diverse associations with psychological distress. The analyses supported a bifactor model of the DASS-21 with three specific factors of depression, anxiety and stress as well as a general distress factor. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: The results show that the DASS-21 may be used to measure unique symptoms of depression, anxiety and, with some caveat, stress as well as overall psychological distress. This study confirms that the DASS-21 is theoretically sound instrument that is feasible for both research and clinical practice. The DASS-21 can be an accessible tool for screening and evaluation in first-line mental health services. Introduction There is a constant need for theoretically sound and valid self-report instruments for measuring psychological distress. Previous studies have shown that the Depression, Anxiety and Stress Scale-21 (DASS-21) is theoretically sound, but there have been some inconsistent results regarding its factor structure. Aims The aim of the present study was to investigate and elucidate the factor structure and convergent validity of the DASS-21. Methods A total of 624 participants recruited from student, primary care and psychotherapy populations. The factor structure of the DASS

  2. Grit, anxiety, and stress in emergency physicians.

    Science.gov (United States)

    Wong, Matthew L; Anderson, Jared; Knorr, Thomas; Joseph, Joshua W; Sanchez, Leon D

    2018-02-26

    The personality traits of emergency physicians are infrequently studied, though interest in physician wellness is increasing. The objective of this study is to acquire pilot data about the amount of grit, anxiety, and stress in emergency physicians using established psychological survey instruments, and to examine their associations of each of these traits with each other. Thirty-six emergency medicine resident and attending physicians from an urban academic medical center consented for enrollment. Participants were administered the Duckworth 12-point Grit Scale, the State-Trait Anxiety Inventory (STAI), and the Perceived Stress Scale (PSS), which measure grit, anxiousness, and perceived stress, respectively. These are the gold standard psychological instruments for each of their areas. We analyzed the results with descriptive statistics, Spearman correlations, and linear regression. Nineteen residents and 17 attending physicians completed the surveys during the first quarter of a new academic year. The mean grit score was 3.7 (95% CI 3.5-3.8, SD: 0.56), the mean trait-anxiety score was 32.61 (95% CI 30.15-35.07, SD: 7.26), and the mean PSS score was 12.28 (95% CI 10.58-13.97, SD: 4.99). Only trait-anxiety and perceived stress were significantly correlated (Spearman's rho: 0.70, panxious reported more stress. Levels of grit were not associated with trait-anxiety. These psychological concepts should be studied further as they relate to the function and health of emergency medicine providers. Copyright © 2018. Published by Elsevier Inc.

  3. Investigation Effect of Shift Work on Job Burnout and Depression, Anxiety, Stress Scale in Military Personnel

    Directory of Open Access Journals (Sweden)

    Ayoub Ghanbary Sartang

    2018-06-01

    Full Text Available Shift work has been recognized as an important tool for organizing of work in developing countries. The disturbed depression, stress accident are the most common health‐related effects of shift work. The military personnel shift worker during work, are exposed to stress and psychological pressure that certainly affect the efficiency of their work. The aim of this study was to Investigation Effect of shift work on job burnout and Depression, Anxiety, Stress Scale in military personnel. This cross-sectional study was carried out on 100 military personnel male in Southern Iran. Respondents were divided into two groups based on their working schedule (50 shift work personnel / 50 day work personnel. Data collection tools were a Depression, Anxiety, and Stress Scale (DASS-21, demographic characteristics and Maslach job burnout questionnaire. Convenience sampling was used as sampling method. Finally, Data analysis was performed with SPSS (version 20, descriptive statistics, One Way Anova test, ANCOVA and t-independent test. The results of showed that shift work has an impact on burnout and DASS-21 and mean obtained score for DASS-21 and job burnout in shift workers are more day work individuals. Analysis of variance test showed significant difference between job burnout in day workers and shift workers and job burnout were more in shift workers. Also significant difference between DASS-21 in day workers and shift workers and DASS-21 was more in shift workers. This study showed that shift work has an impact on burnout and scale DASS-21 shall is taken to Intervention actions in shift works.

  4. The association of perceived stress and verbal memory is greater in HIV-infected versus HIV-uninfected women.

    Science.gov (United States)

    Rubin, Leah H; Cook, Judith A; Weber, Kathleen M; Cohen, Mardge H; Martin, Eileen; Valcour, Victor; Milam, Joel; Anastos, Kathryn; Young, Mary A; Alden, Christine; Gustafson, Deborah R; Maki, Pauline M

    2015-08-01

    In contrast to findings from cohorts comprised primarily of HIV-infected men, verbal memory deficits are the largest cognitive deficit found in HIV-infected women from the Women's Interagency HIV Study (WIHS), and this deficit is not explained by depressive symptoms or substance abuse. HIV-infected women may be at greater risk for verbal memory deficits due to a higher prevalence of cognitive risk factors such as high psychosocial stress and lower socioeconomic status. Here, we investigate the association between perceived stress using the Perceived Stress Scale (PSS-10) and verbal memory performance using the Hopkins Verbal Learning Test (HVLT) in 1009 HIV-infected and 496 at-risk HIV-uninfected WIHS participants. Participants completed a comprehensive neuropsychological test battery which yielded seven cognitive domain scores, including a primary outcome of verbal memory. HIV infection was not associated with a higher prevalence of high perceived stress (i.e., PSS-10 score in the top tertile) but was associated with worse performance on verbal learning (p memory (p stress was associated with poorer performance in those cognitive domains (p's stress interaction was found only for the verbal memory domain (p = 0.02); among HIV-infected women only, high stress was associated with lower performance (p's memory measure in particular. These findings suggest that high levels of perceived stress contribute to the deficits in verbal memory observed in WIHS women.

  5. Rasch model analysis of the Depression, Anxiety and Stress Scales (DASS).

    Science.gov (United States)

    Shea, Tracey L; Tennant, Alan; Pallant, Julie F

    2009-05-09

    There is a growing awareness of the need for easily administered, psychometrically sound screening tools to identify individuals with elevated levels of psychological distress. Although support has been found for the psychometric properties of the Depression, Anxiety and Stress Scales (DASS) using classical test theory approaches it has not been subjected to Rasch analysis. The aim of this study was to use Rasch analysis to assess the psychometric properties of the DASS-21 scales, using two different administration modes. The DASS-21 was administered to 420 participants with half the sample responding to a web-based version and the other half completing a traditional pencil-and-paper version. Conformity of DASS-21 scales to a Rasch partial credit model was assessed using the RUMM2020 software. To achieve adequate model fit it was necessary to remove one item from each of the DASS-21 subscales. The reduced scales showed adequate internal consistency reliability, unidimensionality and freedom from differential item functioning for sex, age and mode of administration. Analysis of all DASS-21 items combined did not support its use as a measure of general psychological distress. A scale combining the anxiety and stress items showed satisfactory fit to the Rasch model after removal of three items. The results provide support for the measurement properties, internal consistency reliability, and unidimensionality of three slightly modified DASS-21 scales, across two different administration methods. The further use of Rasch analysis on the DASS-21 in larger and broader samples is recommended to confirm the findings of the current study.

  6. Validity of the Depression Anxiety Stress Scales in assessing depression and anxiety following traumatic brain injury.

    Science.gov (United States)

    Dahm, Jane; Wong, Dana; Ponsford, Jennie

    2013-10-01

    Anxiety and depression following traumatic brain injury (TBI) are associated with poorer outcomes. A brief self-report questionnaire would assist in identifying those at risk, however validity of such measures is complicated by confounding symptoms of the injury. This study investigated the validity of the Depression Anxiety Stress Scales (DASS) and Hospital Anxiety and Depression Scale (HADS), in screening for clinical diagnoses of anxiety and mood disorders following TBI. One hundred and twenty-three participants with mild to severe TBI were interviewed using the SCID (Axis I) and completed the DASS and HADS. The DASS, DASS21 and HADS scales demonstrated validity compared with SCID diagnoses of anxiety and mood disorders as measured by Area Under ROC Curve, sensitivity and specificity. Validity of the DASS depression scale benefited from items reflecting symptoms of devaluation of life, self-deprecation, and hopelessness that are not present on the HADS. Validity of the HADS anxiety scale benefited from items reflecting symptoms of tension and worry that are measured separately for the DASS on the stress scale. Participants were predominantly drawn from a rehabilitation centre which may limit the extent to which results can be generalized. Scores for the DASS21 were derived from the DASS rather than being administered separately. The DASS, DASS21 and HADS demonstrated validity as screening measures of anxiety and mood disorders in this TBI sample. The findings support use of these self-report questionnaires for individuals with TBI to identify those who should be referred for clinical diagnostic follow-up. © 2013 Elsevier B.V. All rights reserved.

  7. Rasch model analysis of the Depression, Anxiety and Stress Scales (DASS)

    Science.gov (United States)

    Shea, Tracey L; Tennant, Alan; Pallant, Julie F

    2009-01-01

    Background There is a growing awareness of the need for easily administered, psychometrically sound screening tools to identify individuals with elevated levels of psychological distress. Although support has been found for the psychometric properties of the Depression, Anxiety and Stress Scales (DASS) using classical test theory approaches it has not been subjected to Rasch analysis. The aim of this study was to use Rasch analysis to assess the psychometric properties of the DASS-21 scales, using two different administration modes. Methods The DASS-21 was administered to 420 participants with half the sample responding to a web-based version and the other half completing a traditional pencil-and-paper version. Conformity of DASS-21 scales to a Rasch partial credit model was assessed using the RUMM2020 software. Results To achieve adequate model fit it was necessary to remove one item from each of the DASS-21 subscales. The reduced scales showed adequate internal consistency reliability, unidimensionality and freedom from differential item functioning for sex, age and mode of administration. Analysis of all DASS-21 items combined did not support its use as a measure of general psychological distress. A scale combining the anxiety and stress items showed satisfactory fit to the Rasch model after removal of three items. Conclusion The results provide support for the measurement properties, internal consistency reliability, and unidimensionality of three slightly modified DASS-21 scales, across two different administration methods. The further use of Rasch analysis on the DASS-21 in larger and broader samples is recommended to confirm the findings of the current study. PMID:19426512

  8. Rasch model analysis of the Depression, Anxiety and Stress Scales (DASS

    Directory of Open Access Journals (Sweden)

    Tennant Alan

    2009-05-01

    Full Text Available Abstract Background There is a growing awareness of the need for easily administered, psychometrically sound screening tools to identify individuals with elevated levels of psychological distress. Although support has been found for the psychometric properties of the Depression, Anxiety and Stress Scales (DASS using classical test theory approaches it has not been subjected to Rasch analysis. The aim of this study was to use Rasch analysis to assess the psychometric properties of the DASS-21 scales, using two different administration modes. Methods The DASS-21 was administered to 420 participants with half the sample responding to a web-based version and the other half completing a traditional pencil-and-paper version. Conformity of DASS-21 scales to a Rasch partial credit model was assessed using the RUMM2020 software. Results To achieve adequate model fit it was necessary to remove one item from each of the DASS-21 subscales. The reduced scales showed adequate internal consistency reliability, unidimensionality and freedom from differential item functioning for sex, age and mode of administration. Analysis of all DASS-21 items combined did not support its use as a measure of general psychological distress. A scale combining the anxiety and stress items showed satisfactory fit to the Rasch model after removal of three items. Conclusion The results provide support for the measurement properties, internal consistency reliability, and unidimensionality of three slightly modified DASS-21 scales, across two different administration methods. The further use of Rasch analysis on the DASS-21 in larger and broader samples is recommended to confirm the findings of the current study.

  9. Total dynamic response of a PSS vehicle negotiating asymmetric road excitations

    Science.gov (United States)

    Zhu, Jian Jun; Khajepour, Amir; Esmailzadeh, Ebrahim

    2012-12-01

    A planar suspension system (PSS) is a novel automobile suspension system in which an individual spring-damper strut is implemented in both the vertical and longitudinal directions, respectively. The wheels in a vehicle with such a suspension system can move back and forth relative to the chassis. When a PSS vehicle experiences asymmetric road excitations, the relative longitudinal motion of wheels with respect to the chassis in two sides of the same axle are not identical, and thus the two wheels at one axle will not be aligned in the same axis. The total dynamic responses, including those of the bounce, pitch and the roll of the PSS vehicle, to the asymmetric road excitation may exhibit different characteristics from those of a conventional vehicle. This paper presents an investigation into the comprehensive dynamic behaviour of a vehicle with the PSS, in such a road condition, on both the straight and curved roads. The study was carried out using an 18 DOF full-car model incorporating a radial-spring tyre-ground contact model and a 2D tyre-ground dynamic friction model. Results demonstrate that the total dynamic behaviour of a PSS vehicle is generally comparable with that of the conventional vehicle, while PSS exhibits significant improvement in absorbing the impact forces along the longitudinal direction when compared to the conventional suspension system. The PSS vehicle is found to be more stable than the conventional vehicle in terms of the directional performance against the disturbance of the road potholes on a straight line manoeuvre, while exhibiting a very similar handling performance on a curved line.

  10. Using the Depression Anxiety Stress Scale 21 (DASS-21) across cultures.

    Science.gov (United States)

    Oei, Tian P S; Sawang, Sukanlaya; Goh, Yong Wah; Mukhtar, Firdaus

    2013-01-01

    The DASS-21 is a well-established instrument for measuring depression, anxiety, and stress with good reliability and validity reported from Hispanic American, British, and Australian adults. However, the lack of appropriate validation among Asian populations continues to pose concerns over the use of DASS-21 in Asian samples. Cultural variation may influence the individual's experience and emotional expression. Thus, when researchers and practitioners employ Western-based assessments with Asian populations by directly translating them without an appropriate validation, the process can be challenging. We conducted a series of rigorous statistical tests and minimized any potential confounds from the demographic information. Following factor analyses, we performed multigroup analysis across six nations to demonstrate consistency of our findings. The advantages of this revised DASS-18 stress scale are twofold. First, it possesses fewer items, which results in a cleaner factorial structure. Second, it has a smaller interfactor correlation. With these justifications, the revised DASS-18 stress scale is potentially more suitable for Asian populations. Nonetheless, given limitations, findings should be considered preliminary.

  11. Clinical validity of a relocation stress scale for the families of patients transferred from intensive care units.

    Science.gov (United States)

    Oh, HyunSoo; Lee, Seul; Kim, JiSun; Lee, EunJu; Min, HyoNam; Cho, OkJa; Seo, WhaSook

    2015-07-01

    This study was conducted to develop a family relocation stress scale by modifying the Son's Relocation Stress Syndrome Scale, to examine its clinical validity and reliability and to confirm its suitability for measuring family relocation stress. The transfer of ICU patients to general wards is a significant anxiety-producing event for family members. However, no relocation stress scale has been developed specifically for families. A nonexperimental, correlation design was adopted. The study subjects were 95 family members of 95 ICU patients at a university hospital located in Incheon, South Korea. Face and construct validities of the devised family relocation stress scale were examined. Construct validity was examined using factor analysis and by using a nomological validity test. Reliability was also examined. Face and content validity of the scale were verified by confirming that its items adequately measured family relocation stress. Factor analysis yielded four components, and the total variance explained by these four components was 63·0%, which is acceptable. Nomological validity was well supported by significant relationships between relocation stress and degree of preparation for relocation, patient self-care ability, family burden and satisfaction with the relocation process. The devised scale was also found to have good reliability. The family relocation stress scale devised in this study was found to have good validity and reliability, and thus, is believed to offer a means of assessing family relocation stress. The findings of this study provide a reliable and valid assessment tool when nurses prepare families for patient transfer from an ICU to a ward setting, and may also provide useful information to those developing an intervention programme for family relocation stress management. © 2015 John Wiley & Sons Ltd.

  12. Exploring stress levels, job satisfaction, and quality of life in a sample of police officers in Greece.

    Science.gov (United States)

    Alexopoulos, Evangelos C; Palatsidi, Vassiliki; Tigani, Xanthi; Darviri, Christina

    2014-12-01

    The ongoing economic crisis in Greece has affected both stress and quality of life (QoL) at all socioeconomic levels, including professionals in the police force. The aim of this study was to examine perceived stress, job satisfaction, QoL, and their relationships in a sample of police officers in Greece. A cross-sectional study was conducted during the first trimester of 2011 in 23 police stations in the greater Athens area. A total of 201 police officers agreed to participate (response rate 44.6%). The General Health Questionnaire-28 (GHQ-28) was used to assess general health, and the World Health Organization Quality of Life-BREF Questionnaire and Perceived Stress Scale-14 (PSS-14) questionnaires were used to assess QoL and perceived stress, respectively. The PSS and GHQ subscales and total scores exhibited strong, positive, and significant correlations coefficients (r): 0.52 for somatic disturbances, 0.56 for stress and insomnia, 0.40 for social dysfunction, and 0.37 for depression, yielding an r equal to 0.57 for the total GHQ score. A higher level of perceived stress was related to a lower likelihood of being satisfied with their job; in this regard, male participants and higher ranked officers reported lower job satisfaction. The PSS and GHQ scores were inversely, consistently, and significantly related to almost all of the QoL aspects, explaining up to 34% of their variability. Parenthood had a positive effect on QoL related to physical health, and women reported lower QoL related to psychological health. Higher levels of stress are related to an increased risk of reporting suboptimal job satisfaction and QoL. The magnitude of these associations varied depending on age, gender, and rank, highlighting the need for stress-management training.

  13. Association of academic stress with sleeping difficulties in medical students of a Pakistani medical school: a cross sectional survey

    Directory of Open Access Journals (Sweden)

    Ahmed Waqas

    2015-03-01

    Full Text Available Introduction. Medicine is one of the most stressful fields of education because of its highly demanding professional and academic requirements. Psychological stress, anxiety, depression and sleep disturbances are highly prevalent in medical students.Methods. This cross-sectional study was undertaken at the Combined Military Hospital Lahore Medical College and the Institute of Dentistry in Lahore (CMH LMC, Pakistan. Students enrolled in all yearly courses for the Bachelor of Medicine and Bachelor of Surgery (MBBS degree were included. The questionnaire consisted of four sections: (1 demographics (2 a table listing 34 potential stressors, (3 the 14-item Perceived Stress Scale (PSS-14, and (4 the Pittsburgh Quality of Sleep Index (PSQI. Logistic regression was run to identify associations between group of stressors, gender, year of study, student’s background, stress and quality of sleep.Results. Total response rate was 93.9% (263/280 respondents returned the questionnaire. The mean (SD PSS-14 score was 30 (6.97. Logistic regression analysis showed that cases of high-level stress were associated with year of study and academic-related stressors only. Univariate analysis identified 157 cases with high stress levels (59.7%. The mean (SD PSQI score was 8.1 (3.12. According to PSQI score, 203/263 respondents (77% were poor sleepers. Logistic regression showed that mean PSS-14 score was a significant predictor of PSQI score (OR 1.99, P < 0.05.Conclusion. We found a very high prevalence of academic stress and poor sleep quality among medical students. Many medical students reported using sedatives more than once a week. Academic stressors contributed significantly to stress and sleep disorders in medical students.

  14. Assessing health-related quality of life in primary Sjögren's syndrome-The PSS-QoL.

    Science.gov (United States)

    Lackner, Angelika; Stradner, Martin H; Hermann, Josef; Unger, Julia; Stamm, Tanja; Graninger, Winfried B; Dejaco, Christian

    2017-11-27

    To develop a questionnaire for the assessment of health-related quality of life (HRQL) in primary Sjögren's syndrome (PSS), and to test its psychometric properties. Based on the concepts of a previous qualitative study, a questionnaire for the assessment of HRQL in PSS (PSS-QoL) was developed. Psychometric testing of PSS-QoL was performed after revising the first draft with feedback of patients (n = 6) and clinicians (n = 4). Convergent construct validity was assessed by correlating the score with the EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI), EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) and Euro-QoL 5D (EQ-5D). Reliability was examined by asking patients to complete the questionnaire twice 1-2 weeks apart. An English Version of the PSS-QoL was developed by using standard methodology with forward and back translation. Out of the 75 PSS patients, 91% were female, mean (±SD) age was 58.5 ± 12.5 years. PSS-QoL consists of 25 questions and can be divided into two main categories: physical (discomfort and dryness) and psychosocial. The internal consistency of the PSS-QoL revealed a Crohnbach's α of 0.892. Strong and moderate correlations were found between the PSS-QoL and ESSPRI (corr coeff = 0.755) and EQ. 5D-pain/discomfort (corr coeff = 0.531). Reproducibility of the PSS-QoL was high, yielding an ICC of 0.958 (95% CI: 0.926-0.981). The PSS-QoL is the first specific tool for the assessment of patients' HRQL in PSS and showed good psychometric properties. It may serve as a novel patient-reported outcome measure in future clinical studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Effect of Secondary Doping Using Sorbitol on Structure and Transport Properties of PEDOT-PSS Thin Films

    Science.gov (United States)

    Khasim, Syed; Pasha, Apsar; Roy, Aashish S.; Parveen, Ameena; Badi, Nacer

    2017-07-01

    Poly(3,4-ethylene dioxythiophene):poly(styrenesulphonate) (PEDOT-PSS) in the recent past has emerged as one of the most fascinating conducting polymers for many device applications. The unique feature of PEDOT-PSS is its transparency in the entire visible spectrum with excellent thermal stability. The PEDOT-PSS as prepared as an aqueous dispersion has very low conductivity, and it hinders the performance of a device. In this work we report the conductivity enhancement of PEDOT-PSS thin films through secondary doping using a polar organic solvent such as sorbitol. The mechanism of conductivity enhancement was studied through various physical and chemical characterizations. The effect of sorbitol concentration on structure and transport properties of PEDOT-PSS thin films was investigated in detail. The structural and morphological modifications in PEDOT-PSS due to the addition of sorbitol was studied through Fourier transform spectroscopy, Ultra Violet-visible spectroscopy, theromogravimetric analysis, scanning electron microscopy and atomic force microscopy. The interactions resulting from conformational changes of PEDOT chains that changes from coiled to linear structure due to the sorbitol treatment significantly improves the conductivity of PEDOT-PSS films. The secondary doping of sorbitol reduces the energy barrier that facilitates the charge carrier hopping leading to enhanced conductivity. We have observed that the conductivity of PEDOT-PSS thin films was increased by two fold due to sorbitol treatment when compared to conductivity of pure PEDOT-PSS. We have carried out detailed analysis of dielectric parameters of sorbitol-treated PEDOT-PSS films and found that sorbitol treatment has a significant effect on various dielectric attributes of PEDOT-PSS films. Hence, secondary doping using sorbitol could be a useful way to effectively tailor the conductivity and dielectric properties of PEDOT-PSS thin films that can be used as flexible electrodes in

  16. Size scale dependence of compressive instabilities in layered composites in the presence of stress gradients

    DEFF Research Database (Denmark)

    Poulios, Konstantinos; Niordson, Christian Frithiof

    2016-01-01

    The compressive strength of unidirectionally or layer-wise reinforced composite materials in direction parallel to their reinforcement is limited by micro-buckling instabilities. Although the inherent compressive strength of a given material micro-structure can easily be determined by assessing its...... compressive stress but also on spatial stress or strain gradients, rendering failure initiation size scale dependent. The present work demonstrates and investigates the aforementioned effect through numerical simulations of periodically layered structures withnotches and holes under bending and compressive...... loads, respectively. The presented results emphasize the importance of the reinforcing layer thickness on the load carrying capacity of the investigated structures, at a constant volumetric fraction of the reinforcement. The observed strengthening at higher values of the relative layer thickness...

  17. The Femininity Ideology Scale (FIS): dimensions and its relationship to anxiety and feminine gender role stress.

    Science.gov (United States)

    Richmond, Katherine; Levant, Ronald; Smalley, Bryant; Cook, Stephen

    2015-01-01

    The purpose of this study was to conduct a confirmatory factor analytic investigation of the Femininity Ideology Scale (FIS) and to assess whether feminine gender role stress mediated the relationship between femininity ideology and anxiety. During the 2010-2011 academic year, a convenience sample of 606 college women were recruited from three universities and one college. Confirmatory factor analysis supported a four- versus the hypothesized five-factor model, resulting in the elimination of the Dependency/Deference factor. Mediation analysis using structural equation modeling indicated no direct relationship between Femininity Ideology and Anxiety, although an indirect one was observed, mediated through Feminine Gender Role Stress. The results are discussed in terms of possible changes in contemporary notions of femininity, and the utility of using the FIS in applied therapeutic settings.

  18. Versão brasileira da Escala de Estresse Percebido: tradução e validação para idosos Brazilian version of the Perceived Stress Scale: translation and validation for the elderly

    Directory of Open Access Journals (Sweden)

    Caroline Di Bernardi Luft

    2007-08-01

    translated version was applied, by means of interview, to 76 elders aged on average 70.04 years (SD=6.34; range: 60-84. The internal consistency was verified by means of the Cronbach's alpha coefficient and the construct validity was analyzed by means of factorial exploratory analysis with varimax rotation. Full and shortened score means were analyzed comparing the perceived stress in terms of self-assessment of health, perceived socioeconomic condition, marital status, and living conditions, among others. RESULTS: As for reliability, the full version has showed similar internal consistency (r=0.82 compared to the shortened one (r=0.83. The factorial analysis found two factors for the full and one factor for the shortened scale. Question 12 showed the lowest factorial loads. When analyzing PSS likelihood of differentiating the perceived stress in terms of the study variables, it was found the full scale had greater differences in perceived stress than the shortened scale. CONCLUSIONS: The Perceived Stress Scale proved to be a clear and reliable tool to measure the perceived stress of Brazilian elderly, showing suitable psychometric performance.

  19. Preparation of 2D MoSe2/PEDOT:PSS composite and its thermoelectric properties

    Science.gov (United States)

    Li, Xia; Liu, Congcong; Wang, Tongzhou; Wang, Wenfang; Wang, Xiaodong; Jiang, Qinglin; Jiang, Fengxing; Xu, Jingkun

    2017-11-01

    Nowadays, inorganic/polymer composites have attracted significant interest in thermoelectric field, since the composite materials usually achieve their respective advantages complementary to each other. In this work, molybdenum diselenide (MoSe2) was synthesized by a facile hydrothermal method. Solution processible two-dimensional (2D) MoSe2 nanosheets (NSs) were successfully obtained using dimethylsulfoxide (DMSO) solvent or lithium intercalation procedure. Combined with Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), MoSe2/PEDOT:PSS composite thin films were fabricated by direct vacuum-filtration method. Thermoelectric properties of composite thin films were investigated systematically and found that 2D MoSe2 NSs and PEDOT:PSS have the synergistic effect on improving thermoelectric properties. The maximum power factor was calculated to be 48.6 µW m-1 K-2 with 5 wt% 2D MoSe2 NSs embedding into PEDOT:PSS matrix, which is almost 69% higher than that of pure PEDOT:PSS. These results demonstrate that 2D inorganic/polymer composite method is one of promising strategies to get high-performance polymer-based thermoelectric composites.

  20. Spray-deposited PEDOT:PSS for inverted organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Weickert, Jonas; Sun, Haiyan; Palumbiny, Claudia; Hesse, Holger Christian; Schmidt-Mende, Lukas [Ludwig-Maximilians-University Munich, Department of Physics and Center for NanoScience (CeNS), Amalienstr. 54, 80799 Munich (Germany)

    2010-12-15

    The method of spray-depositing PEDOT:PSS allows the fabrication of thin films with controlled thickness on polymer layers. PEDOT:PSS is used in inverted ITO/TiO{sub 2}/P3HT:PCBM/PEDOT:PSS/Ag solar cells to optimize the work function of the hole-collecting electrode. The interlayer is also found to protect the organic layer during metal top deposition and improve the contact between P3HT-PCBM and the Ag electrode, which is confirmed using two different metal-deposition techniques; thermal evaporation and sputtering. Cells with PEDOT:PSS show full V{sub OC} and efficiency immediately after fabrication, whereas devices without PEDOT:PSS exhibit low performance in the beginning and improve significantly during the first 10 days after production. Devices are long-term stable if stored in the dark and in ambient air and show no significant performance decrease after 80 days. No inert nitrogen atmosphere is needed for any fabrication step, thus reducing the potential production costs since no glove box has to be used. (author)

  1. Low-Temperature Cross-Linking of PEDOT:PSS Films Using Divinylsulfone.

    Science.gov (United States)

    Mantione, Daniele; Del Agua, Isabel; Schaafsma, Wandert; ElMahmoudy, Mohammed; Uguz, Ilke; Sanchez-Sanchez, Ana; Sardon, Haritz; Castro, Begoña; Malliaras, George G; Mecerreyes, David

    2017-05-31

    Recent interest in bioelectronics has prompted the exploration of properties of conducting polymer films at the interface with biological milieus. Poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS) from a commercially available source has been used as a model system for these studies. Different cross-linking schemes have been used to stabilize films of this material against delamination and redispersion, but the cost is a decrease in the electrical conductivity and/or additional heat treatment. Here we introduce divinylsulfone (DVS) as a new cross-linker for PEDOT:PSS. Thanks to the higher reactiveness of the vinyl groups of DVS, the cross-linking can be performed at room temperature. In addition, DVS does not reduce electronic conductivity of PEDOT:PSS but rather increases it by acting as a secondary dopant. Cell culture studies show that PEDOT:PSS:DVS films are cytocompatible and support neuroregeneration. As an example, we showed that this material improved the transconductance value and stability of an organic electrochemical transistor (OECT) device. These results open the way for the utilization of DVS as an effective cross-linker for PEDOT:PSS in bioelectronics applications.

  2. Psychometric properties of the Depression Anxiety Stress Scales (DASS) in depressed clinical samples.

    Science.gov (United States)

    Page, Andrew C; Hooke, Geoffrey R; Morrison, David L

    2007-09-01

    The psychometric properties of the Depression Anxiety Stress Scales (DASS; Lovibond & Lovibond, 1995a) were examined in depressed psychiatric hospital samples. Three studies administered the DASS and other symptom measures at admission and discharge to consecutive adult hospital patients with a primary diagnosis of depression. Study 3 aimed to address problems with the DASS by extending the response options. Study 1 found that the DASS had good reliability and validity, was moderately sensitive to change, but the Depression Scale exhibited a ceiling effect. In Study 2, confirmatory factor analysis supported a three-factor structure and the DASS continued to demonstrate good psychometric properties, but the ceiling effect was replicated. Study 3 found that by extending the response scale to include an additional option, the factor structure of the instrument as a whole was maintained, the sensitivity to treatment was increased, but the ceiling effect was only marginally reduced. The psychometric properties of the DASS were sound in clinically depressed samples, but the Depression Scale exhibited a ceiling effect that could not be resolved with minor changes to the scale. Suggestions for revisions of the DASS are made.

  3. Effect of incorporation of silver nanoparticles in PEDOT:PSS layer on performance of organic solar cell

    Science.gov (United States)

    Singh, Joginder; Nirwal, Varun Singh; Bhatnagar, P. K.; Peta, Koteswara Rao

    2018-05-01

    Solution processable organic solar cells have attracted significant interest in scientific community due to their easy processability, flexibility and eco friendly fabrication. In these organic solar cells structure, PEDOT:PSS layer has major importance as it used as hole transporting layer. In the present work, we have analyzed the effect of incorporation of silver nanoparticles (AgNPs) in PEDOT:PSS layer for P3HT:PCBM based organic solar cells. The presence of Ag nanoparticles in PEDOT:PSS film is confirmed by atomic force microscopy (AFM) images. It has been observed that PEDOT:PSS layer with AgNPs has ˜5.4% more transmittance than PEDOT:PSS layer in most of the visible region, which helps in reaching more light on active layer. Finally, solar cell with structure ITO/PEDOT:PSS:AgNPs/Al is fabricated and J-V characteristics are plotted under illumination. It is observed that there is a significant (˜10%) enhancement in short circuit current and slight increment in open circuit voltage with addition of AgNPs in PEDOT:PSS layer. The calculated value of power conversion efficiency (PCE) of fabricated device without AgNPs in PEDOT:PSS was 1.67%, which increased to 2.02% after addition of AgNPs in PEDOT:PSS layer.

  4. Effects of chronic stress and interleukin-10 gene polymorphisms on antibody response to tetanus vaccine in family caregivers of patients with Alzheimer's disease.

    Science.gov (United States)

    Li, Jian; Cowden, Linda G; King, Janice D; Briles, David A; Schroeder, Harry W; Stevens, Alan B; Perry, Rodney T; Chen, Zuomin; Simmons, Micah S; Wiener, Howard W; Tiwari, Hemant K; Harrell, Lindy E; Go, Rodney C P

    2007-01-01

    To assess the effects of psychological stress on the antibody response to tetanus vaccine adjusting for cytokine gene polymorphisms and other nongenetic factors in caregivers of patients with Alzheimer's disease (AD). A family-based follow-up study was conducted in 119 spouses and offspring of community-dwelling patients with AD. Psychological stress was measured by the Perceived Stress Scale (PSS) and the Center for Epidemiologic Studies Depression (CES-D) scale at baseline and 1 month after the vaccination. Nutritional status, health behaviors, comorbidity, and stress-buffering factors were assessed by self-administered questionnaires, 10 single nucleotide polymorphisms (SNP) from six selected cytokines genotyped, and anti-tetanus toxoid immunoglobulin G (IgG) concentrations tested using enzyme-linked immunosorbent assays. The effects of stress and other potential confounders were assessed by mixed models that account for familial correlations. The baseline PSS score, the baseline CES-D score, the interleukin-10-1082 A>G SNP GG genotype, and the baseline anti-tetanus IgG were inversely associated with antibody fold increase. Both psychological stress and cytokine gene polymorphisms affected antibody fold increase. The study provided additional support for the detrimental effects of psychological stress on the antibody response to tetanus vaccine.

  5. Recovery from work-related stress: a randomized controlled trial of a stress management intervention in a clinical sample.

    Science.gov (United States)

    Glasscock, David J; Carstensen, Ole; Dalgaard, Vita Ligaya

    2018-05-28

    Randomized controlled trials (RCTs) of interventions aimed at reducing work-related stress indicate that cognitive behavioural therapy (CBT) is more effective than other interventions. However, definitions of study populations are often unclear and there is a lack of interventions targeting both the individual and the workplace. The aim of this study was to determine whether a stress management intervention combining individual CBT and a workplace focus is superior to no treatment in the reduction of perceived stress and stress symptoms and time to lasting return to work (RTW) in a clinical sample. Patients with work-related stress reactions or adjustment disorders were randomly assigned to an intervention group (n = 57, 84.2% female) or a control group (n = 80, 83.8% female). Subjects were followed via questionnaires and register data. The intervention contained individual CBT and the offer of a workplace meeting. We examined intervention effects by analysing group differences in score changes on the Perceived Stress Scale (PSS-10) and the General Health Questionnaire (GHQ-30). We also tested if intervention led to faster lasting RTW. Mean baseline values of PSS were 24.79 in the intervention group and 23.26 in the control group while the corresponding values for GHQ were 21.3 and 20.27, respectively. There was a significant effect of time. 10 months after baseline, both groups reported less perceived stress and improved mental health. 4 months after baseline, we found significant treatment effects for both perceived stress and mental health. The difference in mean change in PSS after 4 months was - 3.09 (- 5.47, - 0.72), while for GHQ it was - 3.91 (- 7.15, - 0.68). There were no group differences in RTW. The intervention led to faster reductions in perceived stress and stress symptoms amongst patients with work-related stress reactions and adjustment disorders. 6 months after the intervention ended there were no longer differences between

  6. The Psychometric Properties of Turkish Version of Depression Anxiety Stress Scale-21 (DASS-21) in Community and Clinical Samples

    OpenAIRE

    Hakan SARICAM

    2018-01-01

    This paper presented the Turkish version of the Depression Anxiety Stress Scale-21 (DASS-21) in community and clinical samples, examined its psychometric properties. Construct validity and concurrent validity were conducted in validity studies. Depression Anxiety Stress Scale-42 (DASS-42) was used for concurrent validity. In reliability analysis, the instruments internal consistency and re-test reliability were studied. Results of explanatory factor analyses demonstrated that 21 items yielded...

  7. Short version of the Depression Anxiety Stress Scale-21: is it valid for Brazilian adolescents?

    Science.gov (United States)

    Silva, Hítalo Andrade da; Passos, Muana Hiandra Pereira Dos; Oliveira, Valéria Mayaly Alves de; Palmeira, Aline Cabral; Pitangui, Ana Carolina Rodarti; Araújo, Rodrigo Cappato de

    2016-01-01

    To evaluate the interday reproducibility, agreement and validity of the construct of short version of the Depression Anxiety Stress Scale-21 applied to adolescents. The sample consisted of adolescents of both sexes, aged between 10 and 19 years, who were recruited from schools and sports centers. The validity of the construct was performed by exploratory factor analysis, and reliability was calculated for each construct using the intraclass correlation coefficient, standard error of measurement and the minimum detectable change. The factor analysis combining the items corresponding to anxiety and stress in a single factor, and depression in a second factor, showed a better match of all 21 items, with higher factor loadings in their respective constructs. The reproducibility values for depression were intraclass correlation coefficient with 0.86, standard error of measurement with 0.80, and minimum detectable change with 2.22; and, for anxiety/stress: intraclass correlation coefficient with 0.82, standard error of measurement with 1.80, and minimum detectable change with 4.99. The short version of the Depression Anxiety Stress Scale-21 showed excellent values of reliability, and strong internal consistency. The two-factor model with condensation of the constructs anxiety and stress in a single factor was the most acceptable for the adolescent population. Avaliar a reprodutibilidade interdias, a concordância e a validade do construto da versão reduzida da Depression Anxiety Stress Scale-21 aplicada a adolescentes. A amostra foi composta por adolescentes de ambos os sexos, com idades entre 10 e 19 anos, recrutados de escolas e centros esportivos. A validade de construto foi realizada por análise fatorial exploratória, e a confiabilidade foi calculada para cada construto, por meio de coeficiente de correlação intraclasse, erro padrão de medida e mudança mínima detectável. A análise fatorial combinando os itens correspondentes a ansiedade e estresse em um

  8. Oscillation Control in a Synchronous Machine using a Neural based PSS

    Directory of Open Access Journals (Sweden)

    Sandra Milena Pérez Londoño

    2008-01-01

    Full Text Available En este artículo se presenta el diseño y la prueba en laboratorio de un estabilizador de potencia (PSS, basado en redes neuronales. La arquitectura propuesta del PSS utiliza dos redes neuronales, la primera es un controlador que efectúa un control suplementario del sistema de excitación, y una segunda red utilizada para mejorar el desempeño del controlador anterior. Para garantizar la correcta operación del PSS propuesto, éste ha sido entrenado utilizando datos obtenidos a partir de varias condiciones de operación de la máquina, y una amplia variedad de disturbios. La efectividad del método propuesto se confirma a partir de los resultados de las pruebas con máquinas síncronas utilizadas en laboratorio.

  9. Supporting the Development of Environmentally Sustainable PSS by Means of the Ecodesign Maturity Model

    DEFF Research Database (Denmark)

    Pigosso, Daniela Cristina Antelmi; McAloone, Tim C.

    2015-01-01

    best practice for ecodesign implementation and management. The Ecodesign Maturity Model (EcoM2) is a management framework that supports manufacturing companies to consistently and systematicallyimplement ecodesign, based on a step-by-step approach. EcoM2 contains a database containing more than 600...... practices, categorized into management practices, operational practices and methods &tools. Currently, only two management practices of theEcoM2address PSS development. This paper aims to identify the best practices for PSS development, based on a literature review, followed by a presentation of a proposal......Despite their substantial potential for enabling increased environmental performance, product/service-systems (PSS) are not intrinsically environmentally sustainable. In order to ensure increased sustainability performance, PSSand related business models needs to be developed taking into account...

  10. 0268 Is perceived stress related to an increase in salivary cortisol

    DEFF Research Database (Denmark)

    Fink, Samuel; Peter Bonde, Jens; Agergaard Vammen, Marianne

    2014-01-01

    OBJECTIVES: Perceived Stress is a suspected cause of many psychological and physical illnesses. However it remains to be discovered what physiological measures are involved. While it is widely known that acute stress leads to an increase in cortisol levels, the findings in prolonged stress research...... have not been consistent. This study explores the association between Perceived Stress and salivary cortisol levels using the largest population ever used in this field. METHOD: 4467 public employees in the PRISME cohort in 2007. 3217 of those did a similar follow up study in 2009. A 4-item Danish...... version of the PSS-scale was used to measure perceived stress and operationalized as the average score. Salivary cortisol samples were taken at 30 min post awakening and at 8 pm. A mean value of cortisol was calculated. In our analysis we applied logarithmic transformation to the concentrations. RESULTS...

  11. Development and validation of the Acculturative Stress Scale for Chinese College Students in the United States (ASSCS).

    Science.gov (United States)

    Bai, Jieru

    2016-04-01

    Chinese students are the biggest ethnic group of international students in the United States. This study aims to develop a reliable and valid scale to accurately measure their acculturative stress. A 72-item pool was sent online to Chinese students and a five-factor scale of 32 items was generated by exploratory factor analysis. The five factors included language insufficiency, social isolation, perceived discrimination, academic pressure, and guilt toward family. The Acculturative Stress Scale for Chinese Students demonstrated high reliability and initial validity by predicting depression and life satisfaction. It was the first Chinese scale of acculturative stress developed and validated among a Chinese student sample in the United States. In the future, the scale can be used as a diagnostic tool by mental health professionals and a self-assessment tool by Chinese students. (c) 2016 APA, all rights reserved.

  12. Adaptation to Portuguese of the Depression, Anxiety and Stress Scales (DASS) Adaptación para la lengua portuguesa de la Depression, Anxiety and Stress Scale (DASS) Adaptação para a língua portuguesa da Depression, Anxiety and Stress Scale (DASS)

    OpenAIRE

    João Luís Alves Apóstolo; Aida Cruz Mendes; Zaida Aguiar Azeredo

    2006-01-01

    Objective: to adapt to Portuguese, of Portugal, the Depression, Anxiety and Stress Scales, a 21-item short scale (DASS 21), designed to measure depression, anxiety and stress. Method: After translation and back-translation with the help of experts, the DASS 21 was administered to patients in external psychiatry consults (N=101), and its internal consistency, construct validity and concurrent validity were measured. Results: The DASS 21 properties certify its quality to measure emotional state...

  13. Canonical Modeling of the Multi-Scale Regulation of the Heat Stress Response in Yeast

    Directory of Open Access Journals (Sweden)

    Luis L. Fonseca

    2012-02-01

    Full Text Available Heat is one of the most fundamental and ancient environmental stresses, and response mechanisms are found in prokaryotes and shared among most eukaryotes. In the budding yeast Saccharomyces cerevisiae, the heat stress response involves coordinated changes at all biological levels, from gene expression to protein and metabolite abundances, and to temporary adjustments in physiology. Due to its integrative multi-level-multi-scale nature, heat adaptation constitutes a complex dynamic process, which has forced most experimental and modeling analyses in the past to focus on just one or a few of its aspects. Here we review the basic components of the heat stress response in yeast and outline what has been done, and what needs to be done, to merge the available information into computational structures that permit comprehensive diagnostics, interrogation, and interpretation. We illustrate the process in particular with the coordination of two metabolic responses, namely the dramatic accumulation of the protective disaccharide trehalose and the substantial change in the profile of sphingolipids, which in turn affect gene expression. The proposed methods primarily use differential equations in the canonical modeling framework of Biochemical Systems Theory (BST, which permits the relatively easy construction of coarse, initial models even in systems that are incompletely characterized.

  14. Development and validation of a Thai stressful life events rating scale for patients with a diagnosis of schizophrenic methamphetamine abuse

    Directory of Open Access Journals (Sweden)

    Ek-uma Imkome

    2017-04-01

    Full Text Available This study aimed to psychometrically test a Thai Stressful Life Events Rating Scale (TSLERS. Factor analysis was done on data collected from 313 patients with schizophrenia and methamphetamine abuse in Thailand from April to May, 2015. Results identified the following problems impacting physical and mental health: social relationship and social concerns, money, family life, life security, and career. Evaluation of the psychometric scale properties demonstrated acceptable validity and reliability. TSLERS provided scientific and empirical data about stressful life events of patients with schizophrenia and methamphetamine abuse, and was suitable for stress detection and suggesting further innovations.

  15. Characterization of doped PEDOT: PSS and its influence on the performance and degradation of organic solar cells

    International Nuclear Information System (INIS)

    Singh, Vinamrita; Sharma, Vishal; Tandon, R P; Arora, Swati; Arora, Manoj

    2014-01-01

    The present work is a detailed study of the optical, morphological and electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), PEDOT:PSS, films doped with ethylene glycol (EG) and multi-walled carbon nanotubes (MWCNT). The conductivity of PEDOT:PSS films doped with EG and MWCNT is higher than pristine PEDOT:PSS film. The optical transparency of PEDOT:PSS film decreases insignificantly after addition of MWCNT and EG. The films were further studied using atomic force microscopy,  x-ray diffraction, Raman spectroscopy and Kelvin probe work function measurement, after which films of PEDOT:PSS with EG and MWCNT were optimized for the fabrication of solar cells. The optimized film was used as a hole extracting layer in a typical ITO/PEDOT:PSS/P3HT:PCBM/Al solar cell. The suitable concentration for an optimized film was found to be 4% MWCNT and 1:4 ratio of EG to PEDOT:PSS. The performance of the device with doped PEDOT:PSS was found to improve in terms of short circuit current density (J SC ) and efficiency (η). The solar cell with a doped PEDOT:PSS layer showed higher J SC  and η due to the increase in the interchains among PEDOT chains along with the introduction of MWCNT channels in PEDOT:PSS matrix. The degradation behavior of the cells was studied and it was found that both pristine and doped PEDOT:PSS cells showed similar trends of degradation. The performance degradation with time was also studied under variable environmental conditions, which showed different aging rates for the two devices. (paper)

  16. EXPLORING PHYSICIANS' DISSATISFACTION AND WORK-RELATED STRESS: DEVELOPMENT OF THE PhyDis SCALE

    Directory of Open Access Journals (Sweden)

    Monica Pedrazza

    2016-08-01

    Full Text Available Research, all over the world, is starting to recognize the potential impact of physicians’ dissatisfaction and burnout on their productivity, that is, on their intent to leave the job, on their work ability, on the amount of sick leave days, on their intent to continue practicing, and last but not least, on the quality of the services provided, which is an essential part of the general medical care system. It was interest of the provincial medical board’s ethical committee to acquire information about physician’s work-related stress and dissatisfaction. The research group was committed to define the indicators of dissatisfaction and work-related stressors. Focus groups were carried out, 21 stressful experience’s indicators were identified; we developed an online questionnaire to assess the amount of perceived stress relating to each indicator at work (3070 physicians were contacted by e-mail; quantitative and qualitative data analysis were carried out. The grounded theory perspective was applied in order to assure the most reliable procedure to investigate the concepts’ structure of work-related stress. We tested the five dimensions' model of the stressful experience with a confirmatory factor analysis: Personal Costs; Decline in Public Image and Role Uncertainty; Physician's Responsibility toward hopelessly ill Patients; Relationship with Staff and Colleagues; Bureaucracy. We split the sample according to attachment style (secure and insecure -anxious and avoidant-. Results show the complex representation of physicians’ dissatisfaction at work also with references to the variable of individual difference of attachment security/insecurity. The discriminant validity of the scale was tested. The original contribution of this paper lies on the one hand in the qualitative in depth inductive analysis of physicians’ dissatisfaction starting from physicians’ perception, on the other hand, it represents the first attempt to analyze the

  17. Exploring Physicians' Dissatisfaction and Work-Related Stress: Development of the PhyDis Scale.

    Science.gov (United States)

    Pedrazza, Monica; Berlanda, Sabrina; Trifiletti, Elena; Bressan, Franco

    2016-01-01

    Research, all over the world, is starting to recognize the potential impact of physicians' dissatisfaction and burnout on their productivity, that is, on their intent to leave the job, on their work ability, on the amount of sick leave days, on their intent to continue practicing, and last but not least, on the quality of the services provided, which is an essential part of the general medical care system. It was interest of the provincial medical board's ethical committee to acquire information about physician's work-related stress and dissatisfaction. The research group was committed to define the indicators of dissatisfaction and work-related stressors. Focus groups were carried out, 21 stressful experience's indicators were identified; we developed an online questionnaire to assess the amount of perceived stress relating to each indicator at work (3070 physicians were contacted by e-mail); quantitative and qualitative data analysis were carried out. The grounded theory perspective was applied in order to assure the most reliable procedure to investigate the concepts' structure of "work-related stress." We tested the five dimensions' model of the stressful experience with a confirmatory factor analysis: Personal Costs; Decline in Public Image and Role Uncertainty; Physician's Responsibility toward hopelessly ill Patients; Relationship with Staff and Colleagues; Bureaucracy. We split the sample according to attachment style (secure and insecure -anxious and avoidant-). Results show the complex representation of physicians' dissatisfaction at work also with references to the variable of individual difference of attachment security/insecurity. The discriminant validity of the scale was tested. The original contribution of this paper lies on the one hand in the qualitative in depth inductive analysis of physicians' dissatisfaction starting from physicians' perception, on the other hand, it represents the first attempt to analyze the physicians' dissatisfaction with

  18. The Psychometric Properties of Turkish Version of Depression Anxiety Stress Scale-21 (DASS-21 in Community and Clinical Samples

    Directory of Open Access Journals (Sweden)

    Hakan SARICAM

    2018-04-01

    Full Text Available This paper presented the Turkish version of the Depression Anxiety Stress Scale-21 (DASS-21 in community and clinical samples, examined its psychometric properties. Construct validity and concurrent validity were conducted in validity studies. Depression Anxiety Stress Scale-42 (DASS-42 was used for concurrent validity. In reliability analysis, the instrument’s internal consistency and re-test reliability were studied. Results of explanatory factor analyses demonstrated that 21 items yielded three-factors. Results of confirmatory factor analyses for three-dimensional model showed that acceptable fit index values in community sample and perfect fit index values in clinical sample. Factor loadings ranged from .42 to .72. In the concurrent validity, significant positive relationships were found between DASS-42 and DASS-21. Cronbach alpha internal consistency coefficient was found as α= .87 for depression sub-scale, α= .85 for anxiety sub-scale and α= .81 for stress sub-scale in clinical sample. Moreover, test-retest reliability coefficient was obtained as r=.68 for depression sub-scale, r=.66 for anxiety sub-scale and r=.61 for stress sub-scale in community sample, and corrected item-total correlations ranged from .43 to .77 in clinical sample. In second study, DASS-21 discriminated the patients (depression mean score=10.83; anxiety mean score=10.39; stress mean score=11.85 from the healthy subjects (depression mean score=5.88; anxiety mean score=5.37; stress mean score=7.90 well (U=5310.50; 4748.50; 5562.50, p=0.00. According to psychometric properties, DASS-21 is a reliable and valid instrument in the assessment of depression, anxiety, stress levels. [JCBPR 2018; 7(1.000: 19-30

  19. Anxiety, Anxiety Sensitivity, and Perceived Stress as Predictors of Recent Drinking, Alcohol Craving, and Social Stress Response in Heavy Drinkers.

    Science.gov (United States)

    McCaul, Mary E; Hutton, Heidi E; Stephens, Mary Ann C; Xu, Xiaoqiang; Wand, Gary S

    2017-04-01

    Stress and anxiety are widely considered to be causally related to alcohol craving and consumption, as well as development and maintenance of alcohol use disorder (AUD). However, numerous preclinical and human studies examining effects of stress or anxiety on alcohol use and alcohol-related problems have been equivocal. This study examined relationships between scores on self-report anxiety, anxiety sensitivity, and stress measures and frequency and intensity of recent drinking, alcohol craving during early withdrawal, as well as laboratory measures of alcohol craving and stress reactivity among heavy drinkers with AUD. Media-recruited, heavy drinkers with AUD (N = 87) were assessed for recent alcohol consumption. Anxiety and stress levels were characterized using paper-and-pencil measures, including the Beck Anxiety Inventory (BAI), the Anxiety Sensitivity Index-3 (ASI-3), and the Perceived Stress Scale (PSS). Eligible subjects (N = 30) underwent alcohol abstinence on the Clinical Research Unit; twice daily measures of alcohol craving were collected. On day 4, subjects participated in the Trier Social Stress Test; measures of cortisol and alcohol craving were collected. In multivariate analyses, higher BAI scores were associated with lower drinking frequency and reduced drinks/drinking day; in contrast, higher ASI-3 scores were associated with higher drinking frequency. BAI anxiety symptom and ASI-3 scores also were positively related to Alcohol Use Disorders Identification Test total scores and AUD symptom and problem subscale measures. Higher BAI and ASI-3 scores but not PSS scores were related to greater self-reported alcohol craving during early alcohol abstinence. Finally, BAI scores were positively related to laboratory stress-induced cortisol and alcohol craving. In contrast, the PSS showed no relationship with most measures of alcohol craving or stress reactivity. Overall, clinically oriented measures of anxiety compared with perceived stress were more

  20. [Organizational well-being and work-related stress in health care organizations: validation of the Work-related Stress Assessment Scale].

    Science.gov (United States)

    Coluccia, Anna; Lorini, Francesca; Ferretti, Fabio; Pozza, Andrea; Gaetani, Marco

    2015-01-01

    The issue of the assessment of work-related stress has stimulated in recent years, the production of several theoretical paradigms and assessment tools. In this paper we present a new scale for the assessment of organizational well-being and work-related stress specific for healthcare organizations (Work-related Stress Assessment Scale - WSAS). The goal of the authors is to examine the psychometric properties of the scale, so that it can be used in the healthcare setting as a work-related stress assessment tool. The answers of 230 healthcare professionals belonging to different roles have been analyzed. The study was realized in 16 Units of the University Hospital "S. Maria alle Scotte "of Siena. The exploratory factor analysis (EFA) revealed the presence of five factors with good internal consistency and reliability, "relationship to the structure of proximity" (α = 0.93) "change" (α = 0.92), "organization of work "(α = 0.81)," relationship with the company / Governance "(α = 0.87)" working environment "(α = 0.83). The analysis of SEM (Structural Equation Models) has confirmed the goodness of the factor solution (NNFI = 0.835, CFI = 0.921, RMSEA = 0.060). The good psychometric qualities, the shortness and simplicity of the scale WSAS makes it a useful aid in the assessment of work-related stress in health care organizations.

  1. Measuring grandparenthood stress and reward: Developing a scale based on perceptions by grandparents with adolescent grandchildren in Hong Kong.

    Science.gov (United States)

    Wei-Qun, Lou Vivian; Chi, Iris

    2008-12-01

    To develop a Grandparent Stress and Reward Scale (GSRS) for grandparents with adolescent grandchildren in a Chinese context. Twenty-three grandparents with adolescent grandchildren were given in-depth interviews on perceived grandparenthood stress and reward to develop the GSRS. The GSRS was then tested on 107 older adults (mean age, 75.8 years) whose youngest grandchildren were aged 12 or older, living in the community, and were recruited from elderly service agencies. Face-to-face interviews were conducted with a standardized questionnaire which included the GSRS, Life Satisfaction Scale for Chinese Elders (LSS-C), a single-item measure on grandparenthood stress, and demographic measures. The GSRS has satisfactory structure validity. It measures three aspects of reward (self-esteem and life satisfaction, life-long learning opportunity, and grandchildren support), and two aspects of stress (relationship-oriented stress and grandchildren-oriented stress). GSRS was correlated with LSS-C and perceived grandparenthood stress as theoretically expected, which supported its criteria-related validity. It also had satisfactory reliability based on the internal consistency coefficient. The GSRS was a valid and reliable measure that assesses meaning given to grandparents' perception on reward and stress in relations with adolescent grandchildren in a Chinese context. The underlying construct of the scale suggested that the meaning given to grandparenthood in the Chinese context was still influenced by the Confucian tradition.

  2. Experimental determination of the micro-scale strength and stress-strain relation of an epoxy resin

    DEFF Research Database (Denmark)

    Zike, Sanita; Sørensen, Bent F.; Mikkelsen, Lars Pilgaard

    2016-01-01

    An approach is developed for determining the stress-strain law and a failure stress appropriate for micro-mechanical models of polymer materials. Double cantilever beam test specimens, made of an epoxy polymer with notches having finite root radius, were subjected to pure bending moments in an en......An approach is developed for determining the stress-strain law and a failure stress appropriate for micro-mechanical models of polymer materials. Double cantilever beam test specimens, made of an epoxy polymer with notches having finite root radius, were subjected to pure bending moments......-scale (5–6%). The hardening exponent of a power law hardening material was obtained by the use of the J-integral, estimating the strain energy density around the notch. The hardening exponent was found to be within the range of 5–6 and the corresponding micro-scale failure stress was in the range of 220...

  3. Reynolds stress scaling in pipe flow turbulence-first results from CICLoPE.

    Science.gov (United States)

    Örlü, R; Fiorini, T; Segalini, A; Bellani, G; Talamelli, A; Alfredsson, P H

    2017-03-13

    This paper reports the first turbulence measurements performed in the Long Pipe Facility at the Center for International Cooperation in Long Pipe Experiments (CICLoPE). In particular, the Reynolds stress components obtained from a number of straight and boundary-layer-type single-wire and X-wire probes up to a friction Reynolds number of 3.8×10 4 are reported. In agreement with turbulent boundary-layer experiments as well as with results from the Superpipe, the present measurements show a clear logarithmic region in the streamwise variance profile, with a Townsend-Perry constant of A 2 ≈1.26. The wall-normal variance profile exhibits a Reynolds-number-independent plateau, while the spanwise component was found to obey a logarithmic scaling over a much wider wall-normal distance than the other two components, with a slope that is nearly half of that of the Townsend-Perry constant, i.e. A 2,w ≈A 2 /2. The present results therefore provide strong support for the scaling of the Reynolds stress tensor based on the attached-eddy hypothesis. Intriguingly, the wall-normal and spanwise components exhibit higher amplitudes than in previous studies, and therefore call for follow-up studies in CICLoPE, as well as other large-scale facilities.This article is part of the themed issue 'Toward the development of high-fidelity models of wall turbulence at large Reynolds number'. © 2017 The Author(s).

  4. Stress

    Science.gov (United States)

    ... can be life-saving. But chronic stress can cause both physical and mental harm. There are at least three different types of stress: Routine stress related to the pressures of work, family, and other daily responsibilities Stress brought about ...

  5. Large area ITO-free flexible white OLEDs with Orgacon™ PEDOT:PSS and printed metal shunting lines

    NARCIS (Netherlands)

    Harkema, S.; Mennema, S.; Barink, M.; Rooms, H.C.A.; Wilsona, J.S.; Mol, A.M.B. van; Bollen, D.

    2009-01-01

    We demonstrate the feasibility of white organic light-emitting diodes that exclude the transparent conductor indium-tinoxide. Instead, a highly conductive Orgacon™ PEDOT:PSS material in combination with a metal support structure is used as transparent anode and hole-injection layer. The PEDOT:PSS

  6. Business-IT alignment in PSS value networks linking customer knowledge management to social customer relationship management

    NARCIS (Netherlands)

    Bagheri, S.; Kusters, R.J.; Trienekens, J.J.M.; Hammoudi, S.; Cordeiro, J.; Maciaszek, L.

    2015-01-01

    Offering a PSS that is based on co-creating value with customer, starts with understanding customer needs. Customer understanding is realized through the process of managing customer knowledge across a PSS value network. In this respect, customer knowledge management (CKM) is seen as a core business

  7. Environmentally Friendly Plasma-Treated PEDOT:PSS as Electrodes for ITO-Free Perovskite Solar Cells.

    Science.gov (United States)

    Vaagensmith, Bjorn; Reza, Khan Mamun; Hasan, Md Nazmul; Elbohy, Hytham; Adhikari, Nirmal; Dubey, Ashish; Kantack, Nick; Gaml, Eman; Qiao, Qiquan

    2017-10-18

    Solution processed poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) transparent electrodes (TEs) offer great potential as a low cost alternative to expensive indium tin oxide (ITO). However, strong acids are typically used for enhancing the conductivity of PEDOT:PSS TEs, which produce processing complexity and environmental issues. This work presents an environmentally friendly acid free approach to enhance the conductivity of PEDOT:PSS using a light oxygen plasma treatment, in addition to solvent blend additives and post treatments. The plasma treatment was found to significantly reduce the sheet resistance of PEDOT:PSS TEs from 85 to as low as 15 Ω sq -1 , which translates to the highest reported conductivity of 5012 S/cm for PEDOT:PSS TEs. The plasma treated PEDOT:PSS TE resulted in an ITO-free perovskite solar cell efficiency of 10.5%, which is the highest reported efficiency for ITO-free perovskite solar cells with a PEDOT:PSS electrode that excludes the use of acid treatments. This research presents the first demonstration of this technology. Moreover, the PEDOT:PSS TEs enabled better charge extraction from the perovskite solar cells and reduced hysteresis in the current density-voltage (J-V) curves.

  8. An HPLC Method for Microanalysis and Pharmacokinetics of Marine Sulfated Polysaccharide PSS-Loaded Poly Lactic-co-Glycolic Acid (PLGA Nanoparticles in Rat Plasma

    Directory of Open Access Journals (Sweden)

    Hua-Shi Guan

    2013-04-01

    Full Text Available This study was aimed at developing a sensitive and selective HPLC method with postcolumn fluorescence derivatization for the detection of propylene glycol alginate sodium sulfate (PSS in rat plasma. Plasma samples were prepared by a simple and fast ultrafiltration method. PSS was extracted from rat plasma with d-glucuronic acid as internal standard. Isocratic chromatographic separation was performed on a TSKgel G2500 PWxL column with the mobile phase of 0.1 M sodium sulfate at a flow rate of 0.5 mL/min. Analyte detection was achieved by fluorescence detection (FLD at 250 nm (excitation and 435 nm (emission using guanidine hydrochloride as postcolumn derivatizing reagent in an alkaline medium at 120 °C. The calibration curve was linear over a concentration range of 1–500 μg/mL, and the lower limit of detection (LLOD was found to be 250 ng/mL. This validated method was applied successfully to the pharmacokinetic study of PSS and PSS-loaded poly lactic-co-glycolic acid (PLGA nanoparticles (PSS-NP in rat plasma after a single intravenous (PSS only and oral administration (PSS and PSS-NP. Significant differences in the main pharmacokinetic parameters of PSS and PSS-NP were observed. The relative bioavailability of PSS-NP was 190.10% compared with PSS which shows that PSS-NP can improve oral bioavailability.

  9. Psychometric properties of the Depression Anxiety and Stress Scale-21 in older primary care patients.

    Science.gov (United States)

    Gloster, Andrew T; Rhoades, Howard M; Novy, Diane; Klotsche, Jens; Senior, Ashley; Kunik, Mark; Wilson, Nancy; Stanley, Melinda A

    2008-10-01

    The Depression Anxiety Stress Scale (DASS) was designed to efficiently measure the core symptoms of anxiety and depression and has demonstrated positive psychometric properties in adult samples of anxiety and depression patients and student samples. Despite these findings, the psychometric properties of the DASS remain untested in older adults, for whom the identification of efficient measures of these constructs is especially important. To determine the psychometric properties of the DASS 21-item version in older adults, we analyzed data from 222 medical patients seeking treatment to manage worry. Consistent with younger samples, a three-factor structure best fit the data. Results also indicated good internal consistency, excellent convergent validity, and good discriminative validity, especially for the Depression scale. Receiver operating curve analyses indicated that the DASS-21 predicted the diagnostic presence of generalized anxiety disorder and depression as well as other commonly used measures. These data suggest that the DASS may be used with older adults in lieu of multiple scales designed to measure similar constructs, thereby reducing participant burden and facilitating assessment in settings with limited assessment resources.

  10. Development of short questionnaire to measure an extended set of role expectation conflict, coworker support and work-life balance: The new job stress scale

    Directory of Open Access Journals (Sweden)

    Abhishek Shukla

    2016-12-01

    Full Text Available This study aimed to investigate the reliability and validity of a new version of job stress scale, which measures the extended set of psychosocial stressors by adding new scales to the current version of the job stress scale. Additional scales were extensively collected from theoretical job stress models and similar questionnaire from different countries. Items were tested in workplace and refined through a pilot survey (n = 400 to examine the reliability and construct validity. Most scales showed acceptable levels of internal consistency, intra-class reliability, and test–retest reliability. Factor analysis and correlation analysis showed that these scales fit the theoretical expectations. These findings provided enough evidences that the new job stress scale is reliable and valid. Although confirmatory analysis should be examined in future studies. The new job stress scale is a useful instrument for organization and academicians to evaluate job stress in modern Indian workplace.

  11. Higher stress scores for female medical students measured by the Kessler Psychological Distress Scale (K10 in Pakistan

    Directory of Open Access Journals (Sweden)

    Khadija Qamar

    2014-10-01

    Full Text Available The aim of this study was to determine the stress level of medical students and the relationship between stress and academic year. A cross-sectional, descriptive study was conducted at an undergraduate medical school with a five-year curriculum, in Pakistan, from January 2014 to April 2014. Medical students in the first four years were included in the study. The Kessler Psychological Distress Scale (K10, a self-administered questionnaire, was distributed to the students. A total of 445 medical students completed the questionnaire. The average stress score was 19.61 (SD = 6.76 with a range from 10 to 43. Stress was experienced by 169 students (41.7%. The scores of female students were higher than scores of males, indicating a higher stress level (P = 0.011. The relationship between stress and academic year was insignificant (P = 0.392.

  12. Effect of assertiveness training on levels of stress and assertiveness experienced by nurses in Taiwan, Republic of China.

    Science.gov (United States)

    Lee, S; Crockett, M S

    1994-01-01

    The purpose of the study was to examine the effectiveness of assertiveness training in improving self-perceived levels of stress and assertiveness among nurses in Taiwan, Republic of China. The two-group experimental design was conducted in a 2,000-bed veteran general hospital. A sample of 60 volunteer Chinese-speaking nurses participated in the study. Subjects were randomly assigned to one of two treatments: assertiveness training (AT) or alternate treatment control (ATC), which served as a control and contained updated knowledge of new computer technology for in patient settings. Subjects in each group participated in six 2-hour workshops in the same two-week period. All subjects were pre-, post-, and follow-up posttested for stress and assertiveness with the Perceived Stress Scale (PSS) and Rathus Assertiveness Schedule (RAS), respectively. Results revealed the following: (1) subjects in both groups of pretest were clearly subassertive and under considerable stress; (2) by the end of training, the AT group scored significantly higher on the rating of assertiveness than those in the ATC group, and had successfully maintained their improvement by the 4-week follow-up; and (3) by the end of training, the AT group reported significantly lower levels of stress than the ATC group as indicated on the PSS, and successfully maintained their improvements at the 4-week follow-up. Overall, the results indicate clear support for the effectiveness of assertiveness training for treating subassertive behaviors and stress in a population of professional nurses in Taiwan.

  13. Pain grade and sleep disturbance in older adults: evaluation the role of pain, and stress for depressed and non-depressed individuals.

    Science.gov (United States)

    Eslami, Vahid; Zimmerman, Molly E; Grewal, Trishdeep; Katz, Mindy; Lipton, Richard B

    2016-05-01

    The aim of this paper was to assess the relationship between pain and sleep in older adults taking depression, stress, and medical comorbidities into account. A cross-sectional analysis was performed using Einstein Aging Study, a community-based cohort study of adults aged 70 years and older. Ratings of pain intensity and interference from the Medical Outcomes Study (MOS) Short-Form 36 were used to assign individuals to low-pain versus high-pain severity. Sleep disturbance was assessed using the nine-item sleep problems index from the Medical Outcomes Study Sleep Scale. Other measures included the Geriatric Depression Scale and Perceived Stress Scale (PSS). Linear regression models were used to assess the association between pain grade and sleep disturbance adjusted for demographics, PSS, Geriatric Depression Scale, and other comorbidities. Five hundred sixty-two eligible participants with a mean age of 78.22 years (standard deviation = 5.43) were included; 64% were women. Pain grade [β = 5.40, 95% confidence interval (CI) 2.56-8.21, p pain grade (β = 3.08, 95% CI 0.32-5.85, p = 0.03) and PSS (β = 0.57, 95% CI 0.39-0.75, p pain and sleep by 34%. Depression, when added to previous model, was also associated with sleep (β = 2.17, 95% CI 1.48-2.85, p pain (β = 2.41, 95% CI -0.25 to 5.08, p = 0.07) and sleep by 22%. Stratified for depression, we found that pain, stress, and other medical comorbidities were significantly associated with sleep disturbance in non-depressed individuals but not individuals with depression. Pain, stress, and medical comorbidities are associated with sleep disturbance, especially in non-depressed older adults. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Towards assessing Product/Service Systems (PSS) within the Danish Maritime Industry

    DEFF Research Database (Denmark)

    Hsuan, Juliana; Andersen, Jakob B.; Bey, Niki

    2012-01-01

    In response to requirements resulting from a changing business landscape from solely physical-product-based value creation towards perfoprmance-based value creation, this paper presents a questionaire-based matrix, the PSS Categorization Matric, that is developed in order to help organizations fi...

  15. Simulation-Based Business Case for PSS: A System Dynamics Framework

    DEFF Research Database (Denmark)

    Rodrigues, Vinicius Picanco; Pigosso, Daniela Cristina Antelmi; McAloone, Tim C.

    2017-01-01

    of a business case for PSS implementation and management, based on a System Dynamics simulation framework. With amaturity-oriented theoretical perspective and the associated capability concepts, the study provides insights into how the development of PSScapabilities can potentially affect corporate performance...

  16. Measuring Malaysia School Resource Centers' Standards through iQ-PSS: An Online Management Information System

    Science.gov (United States)

    Zainudin, Fadzliaton; Ismail, Kamarulzaman

    2010-01-01

    The Ministry of Education has come up with an innovative way to monitor the progress of 9,843 School Resource Centers (SRCs) using an online management information system called iQ-PSS (Quality Index of SRC). This paper aims to describe the data collection method and analyze the current state of SRCs in Malaysia and explain how the results can be…

  17. PSS and TCSC damping controller coordinated design using PSO in multi-machine power system

    Energy Technology Data Exchange (ETDEWEB)

    Shayeghi, H., E-mail: hshayeghi@gmail.co [Technical Engineering Department, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of); Safari, A.; Shayanfar, H.A. [Center of Excellence for Power System Automation and Operation, Electrical Engineering Department, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

    2010-12-15

    The paper develops a new design procedure for simultaneous coordinated designing of the thyristor controlled series capacitor (TCSC) damping controller and power system stabilizer (PSS) in multi-machine power system. The coordinated design problem of PSS and TCSC damping controllers over a wide range of loading conditions is converted to an optimization problem with the time domain-based objective function that is solved by a particle swarm optimization (PSO) technique which has a strong ability to find the most optimistic results. By minimizing the proposed fitness function in which oscillatory characteristics between areas are included and thus the interactions among the TCSC controller and PSS under transient conditions in the multi-machine power system are improved. To ensure the robustness of the proposed stabilizers, the design process takes a wide range of operating conditions into account. The effectiveness of the proposed controller is demonstrated through the nonlinear time-domain simulation and some performance indices studies. The results of these studies show that the proposed coordinated controllers have an excellent capability in damping power system inter-area oscillations and enhance greatly the dynamic stability of the power system. Moreover, it is superior to both the uncoordinated designed stabilizers of the PSS and the TCSC damping controller.

  18. Fully Textile, PEDOT:PSS Based Electrodes for Wearable ECG Monitoring Systems.

    Science.gov (United States)

    Pani, Danilo; Dessi, Alessia; Saenz-Cogollo, Jose F; Barabino, Gianluca; Fraboni, Beatrice; Bonfiglio, Annalisa

    2016-03-01

    To evaluate a novel kind of textile electrodes based on woven fabrics treated with PSS, through an easy fabrication process, testing these electrodes for biopotential recordings. Fabrication is based on raw fabric soaking in PSS using a second dopant, squeezing and annealing. The electrodes have been tested on human volunteers, in terms of both skin contact impedance and quality of the ECG signals recorded at rest and during physical activity (power spectral density, baseline wandering, QRS detectability, and broadband noise). The electrodes are able to operate in both wet and dry conditions. Dry electrodes are more prone to noise artifacts, especially during physical exercise and mainly due to the unstable contact between the electrode and the skin. Wet (saline) electrodes present a stable and reproducible behavior, which is comparable or better than that of traditional disposable gelled Ag/AgCl electrodes. The achieved results reveal the capability of this kind of electrodes to work without the electrolyte, providing a valuable interface with the skin, due to mixed electronic and ionic conductivity of PSS. These electrodes can be effectively used for acquiring ECG signals. Textile electrodes based on PSS represent an important milestone in wearable monitoring, as they present an easy and reproducible fabrication process, very good performance in wet and dry (at rest) conditions and a superior level of comfort with respect to textile electrodes proposed so far. This paves the way to their integration into smart garments.

  19. Impact of PSS and SVC on the Power System Transient Stability

    Directory of Open Access Journals (Sweden)

    Mohammed Omar Benaissa

    2017-06-01

    Full Text Available The Static Var Compensator (SVC is used to improve the stability of the power system because of its role in injecting or absorbing the reactive power in the electrical transmission lines. The Power System Stabilizer (PSS is also a control device which ensures maximum power transfer and thus the stability of the power system enhancement. The PSS has been widely used to damp electromechanical oscillations occur in power systems. If no adequate damping is available, the oscillations will increase leading to instability. The present work is an original contribution to the problem of transient stability in the electrical power system, the authors have made some efforts to illustrate the flexibility and the importance of inserting the SVC alone or with the PSS the fact that maintain the characteristics of the system within acceptable limits in a very short time. The results show that the system has been developed successfully in terms of transient stability in a bi-machine transmission system only with the presence of PSS when a single-phase fault has been occurred, while the presence of SVC is more than essential when a three-phase fault is occurred.

  20. Microscopic understanding of the anisotropic conductivity of PEDOT:PSS thin films

    NARCIS (Netherlands)

    Nardes, A.M.; Kemerink, M.; Janssen, R.A.J.; Bastiaansen, J.J.A.M.; Kiggen, N.M.M.; Langeveld, B.M.W.; Breemen, A.J.J.M. van; Kok, M.M. de

    2007-01-01

    The anisotropic conductivity of spin-coated poly(3,4- ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thin films by temperature-dependent conductivity measurements, has been analyzed. A detailed 3D morphological model was derived from topographic scanning tunneling microscopy (STM) and

  1. The electronic properties of the interface between nickel phthalocyanine and a PEDOT:PSS film

    Czech Academy of Sciences Publication Activity Database

    Petraki, F.; Kennou, S.; Nešpůrek, Stanislav

    2008-01-01

    Roč. 103, č. 3 (2008), 033710/1-033710/6 ISSN 0021-8979 R&D Projects: GA AV ČR KAN401770651; GA MŠk OC 138 Institutional research plan: CEZ:AV0Z40500505 Keywords : NiPC * PEDOT:PSS * XPS Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.201, year: 2008

  2. [Construction of the Time Management Scale and examination of the influence of time management on psychological stress response].

    Science.gov (United States)

    Imura, Tomoya; Takamura, Masahiro; Okazaki, Yoshihiro; Tokunaga, Satoko

    2016-10-01

    We developed a scale to measure time management and assessed its reliability and validity. We then used this scale to examine the impact of time management on psychological stress response. In Study 1-1, we developed the scale and assessed its internal consistency and criterion-related validity. Findings from a factor analysis revealed three elements of time management, “time estimation,” “time utilization,” and “taking each moment as it comes.” In Study 1-2, we assessed the scale’s test-retest reliability. In Study 1-3, we assessed the validity of the constructed scale. The results indicate that the time management scale has good reliability and validity. In Study 2, we performed a covariance structural analysis to verify our model that hypothesized that time management influences perceived control of time and psychological stress response, and perceived control of time influences psychological stress response. The results showed that time estimation increases the perceived control of time, which in turn decreases stress response. However, we also found that taking each moment as it comes reduces perceived control of time, which in turn increases stress response.

  3. Validity and Reliability of the Turkish Version of the DSM-5 Posttraumatic Stress Symptom Severity Scale-Child Form.

    Science.gov (United States)

    Yalin Sapmaz, Şermin; Ergin, Dilek; Özek Erkuran, Handan; Şen Celasin, Nesrin; Öztürk, Masum; Karaarslan, Duygu; Köroğlu, Ertuğrul; Aydemir, Ömer

    2017-09-01

    This study assessed the validity and reliability of the Turkish version of the DSM-5 Posttraumatic Stress Symptom Severity Scale-Child Form for use among the Turkish population. The study group consisted of 30 patients that had been treated in a child psychiatry unit and diagnosed with posttraumatic stress disorder and 83 healthy volunteers that were attending middle or high school during the study period. For reliability analyses, the internal consistency coefficient and the test-retest correlation coefficient were measured. For validity analyses, the exploratory factor analysis and correlation analysis with the Child Posttraumatic Stress Reaction Index for concurrent validity were measured. The Cronbach's alpha (the internal consistency coefficient) of the scale was 0.909, and the test-retest correlation coefficient was 0.663. One factor that could explain 58.5% of the variance was obtained and was congruent with the original construct of the scale. As for concurrent validity, the scale showed high correlation with the Child Posttraumatic Stress Reaction Index. It was concluded that the Turkish version of the DSM-5 Posttraumatic Stress Symptom Severity Scale-Child Form can be used as a valid and reliable tool.

  4. A scaled underwater launch system accomplished by stress wave propagation technique

    International Nuclear Information System (INIS)

    Wei Yanpeng; Wang Yiwei; Huang Chenguang; Fang Xin; Duan Zhuping

    2011-01-01

    A scaled underwater launch system based on the stress wave theory and the slip Hopkinson pressure bar (SHPB) technique is developed to study the phenomenon of cavitations and other hydrodynamic features of high-speed submerged bodies. The present system can achieve a transient acceleration in the water instead of long-time acceleration outside the water. The projectile can obtain a maximum speed of 30 m/s in about 200 μs by the SHPB launcher. The cavitation characteristics in the stage of acceleration and deceleration are captured by the high-speed camera. The processes of cavitation inception, development and collapse are also simulated with the business software FLUENT, and the results are in good agreement with experiment. There is about 20-30% energy loss during the launching processes, the mechanism of energy loss is also preliminary investigated by measuring the energy of the incident bar and the projectile. (authors)

  5. Physical modelling of granular flows at multiple-scales and stress levels

    Science.gov (United States)

    Take, Andy; Bowman, Elisabeth; Bryant, Sarah

    2015-04-01

    The rheology of dry granular flows is an area of significant focus within the granular physics, geoscience, and geotechnical engineering research communities. Studies performed to better understand granular flows in manufacturing, materials processing or bulk handling applications have typically focused on the behavior of steady, continuous flows. As a result, much of the research on relating the fundamental interaction of particles to the rheological or constitutive behaviour of granular flows has been performed under (usually) steady-state conditions and low stress levels. However, landslides, which are the primary focus of the geoscience and geotechnical engineering communities, are by nature unsteady flows defined by a finite source volume and at flow depths much larger than typically possible in laboratory experiments. The objective of this paper is to report initial findings of experimental studies currently being conducted using a new large-scale landslide flume (8 m long, 2 m wide slope inclined at 30° with a 35 m long horizontal base section) and at elevated particle self-weight in a 10 m diameter geotechnical centrifuge to investigate the granular flow behavior at multiple-scales and stress levels. The transparent sidewalls of the two flumes used in the experimental investigation permit the combination of observations of particle-scale interaction (using high-speed imaging through transparent vertical sidewalls at over 1000 frames per second) with observations of the distal reach of the landslide debris. These observations are used to investigate the applicability of rheological models developed for steady state flows (e.g. the dimensionless inertial number) in landslide applications and the robustness of depth-averaged approaches to modelling dry granular flow at multiple scales. These observations indicate that the dimensionless inertial number calculated for the flow may be of limited utility except perhaps to define a general state (e.g. liquid

  6. Cross-cultural validation of the Depression Anxiety Stress Scale-21 in China.

    Science.gov (United States)

    Wang, Kui; Shi, Hai-Song; Geng, Fu-Lei; Zou, Lai-Quan; Tan, Shu-Ping; Wang, Yi; Neumann, David L; Shum, David H K; Chan, Raymond C K

    2016-05-01

    The gap between the demand and delivery of mental health services in mainland China can be reduced by validating freely available and psychometrically sound psychological instruments. The present research examined the Chinese version of the 21-item Depression Anxiety Stress Scales (DASS-21). Study 1 administered the DASS-21 to 1,815 Chinese college students and found internal consistency indices (Cronbach's alpha) of .83, .80, and .82 for the Depression, Anxiety, and Stress subscales, respectively, and .92 for the total DASS total. Test-retest reliability over a 6-month interval was .39 to .46 for each of the 3 subscales and .46 for the total DASS. Moderate convergent validity of the Depression and Anxiety subscales was demonstrated via significant correlations with the Chinese Beck Depression Inventory (r = .51 at Time 1 and r = .64 at Time 2) and the Chinese State-Trait Anxiety Inventory (r = .41), respectively. Confirmatory factor analyses supported the original 3-factor model with 1 minor change (nonnormed fit index [NNFI] = .964, comparative fit index [CFI] = .968, and root mean square error of approximation [RMSEA] = .079). Study 2 examined the clinical utility of the Chinese DASS-21 in 166 patients with schizophrenia and 90 matched healthy controls. Patients had higher Depression and Anxiety but not Stress subscale scores than healthy controls. A discriminant function composed of the linear combination of 3 subscale scores correctly discriminated 69.92% of participants, which again supported the potential clinical utility of the DASS in mainland China. Taken together, findings in these studies support the cross-cultural validity of the DASS-21 in China. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  7. Comparison of exposure to stress and analysis of ways of coping with stress among freight transport and public transport drivers

    Directory of Open Access Journals (Sweden)

    Katarzyna Urbańska

    2016-08-01

    Full Text Available Background: Fast progress in a lot of economic sectors has greatly contributed to a growing role of road transportation systems, including freight transport and passenger transport. The job of professional drivers is regarded as extremely hard and dangerous, it is associated with high risk of health loss and even life loss. This profession is also associated with mental burden, the main cause of the absence at work and alarming number of road accidents. The aim of study was to compare exposure to stress, check the level of stress and ways to cope with stress in 2 groups of drivers (N = 187. Material and Methods: The study was carried out among public transport drivers and freight transport drivers. The authors’ own questionnaire and 2 psychological tests: Perceived Stress Scale (PSS-10 and Posttraumatic Growth Inventory and Inventory to Measure Coping Strategies with Stress (Mini-COPE were used as the study tools. Results: The level of stress is high in both groups, mostly due to a similar type of work. Both groups practice similar ways to cope with stress, but active ways predominate. Conclusions: The work of a professional driver is considered as extremely stressful. The level of stress among professional drivers should be under continuous control. Employers should introduce preventive programs and educate employees about some professional ways to cope with stress. Med Pr 2016;67(4:455–466

  8. Depression Anxiety Stress Scales (DASS-21): Factor Structure in Traumatic Brain Injury Rehabilitation.

    Science.gov (United States)

    Randall, Diane; Thomas, Matt; Whiting, Diane; McGrath, Andrew

    To confirm the construct validity of the Depression Anxiety Stress Scales-21 (DASS-21) by investigating the fit of published factor structures in a sample of adults with moderate to severe traumatic brain injury (posttraumatic amnesia > 24 hours). Archival data from 504 patient records at the Brain Injury Rehabilitation Unit at Liverpool Hospital, Australia. Participants were aged between 16 and 71 years and were engaged in a specialist rehabilitation program. The DASS-21. Two of the 6 models had adequate fit using structural equation modeling. The data best fit Henry and Crawford's quadripartite model, which comprised a Depression, Anxiety and Stress factor, as well as a General Distress factor. The data also adequately fit Lovibond and Lovibond's original 3-factor model, and the internal consistencies of each factor were very good (α = 0.82-0.90). This study confirms the structure and construct validity of the DASS-21 and provides support for its use as a screening tool in traumatic brain injury rehabilitation.

  9. Testing measurement invariance of the Depression, Anxiety, and Stress Scales (DASS-21) across four countries.

    Science.gov (United States)

    Scholten, Saskia; Velten, Julia; Bieda, Angela; Zhang, Xiao Chi; Margraf, Jürgen

    2017-11-01

    The rising burden of mental and behavioral disorders has become a global challenge (Murray et al., 2012). Measurement invariant clinical instruments are necessary for the assessment of relevant symptoms across countries. The present study tested the measurement invariance of the 21-item version of the Depression, Anxiety, and Stress Scales (DASS; Lovibond & Lovibond, 1995b) in Poland, Russia, the United Kingdom (U.K.), and the United States of America (U.S.). Telephone interviews were conducted with population-based samples (nPL = 1003, nRU = 3020, nU.K. = 1002, nU.S. = 1002). The DASS-21 shows threshold measurement invariance. Comparisons of latent means did not indicate differences between U.K. and U.S. However, Polish and Russian samples reported more depressive symptoms compared with U.K. and U.S. samples; the Russian sample had the highest levels of anxiety symptoms and the Polish sample demonstrated the highest stress levels. The DASS-21 can be recommended to meaningfully compare the relationships between variables across groups and to compare latent means in Polish-, Russian-, and English-speaking populations. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  10. Prevalence of Depression, Anxiety and Stress as Measured by the Depression, Anxiety, and Stress Scale (DASS-42) among Secondary School Girls in Abha, Saudi Arabia.

    Science.gov (United States)

    Al-Gelban, Khalid S; Al-Amri, Hasan S; Mostafa, Ossama A

    2009-08-01

    To determine the prevalence of symptoms of depression, anxiety and stress among secondary school girls. A cross- sectional study was carried out on secondary school girls in Abha city, Aseer Region, Saudi Arabia, using the Arabic version of the Depression, Anxiety, and Stress Scale (DASS-42). Of 545 female students recruited in this study, 73.4% had the symptoms of at least one of the three studied disorders; 50.1% had at least two disorders. The prevalence of symptoms of depression, anxiety and stress was 41.5 %, 66.2% and 52.5% respectively. The majority of symptoms were mild to moderate in severity. The scores for depression, anxiety, and stress were positively and significantly correlated. No significant association was found between the girls' sociodemographic characteristics and the scores of the three studied disorders. One of the most important aspects of a primary care physician's care of females is to screen for and treat common mental disorders.

  11. Stress effects in cylindrical tubes of austenitic and ferritic/martensitic steels with oxide scales. Materials selection for a HPLWR

    International Nuclear Information System (INIS)

    Steiner, H.

    2002-11-01

    In the frame of the studies for a high performance concept of a light water reactor (LWR) different materials for the cladding are investigated, among them are austenitic and ferritic/martensitic (f/m) steels of different Cr content. Due to the envisaged very extended life times of the fuel elements in the reactor, corrosion problems may arise. Thus, cracking and/or spalling effects in oxide scales on metallic components may play an important role in the corrosion process as they lead, in general, to a drastic enhancement in the oxidation rates. Analytical models for different fundamental stress problems in the compound oxide scale/metallic substrate have been developed and implemented in the computer code OXSPA. These models concern the growth stresses in the cylindrical tubes, the stresses due to temperature changes and radial temperature gradients and the stresses due to inside and outside pressures. (orig.)

  12. Factorial Validity and Internal Consistency of Malaysian Adapted Depression Anxiety Stress Scale - 21 in an Adolescent Sample

    OpenAIRE

    Hairul Anuar Hashim; Freddy Golok; Rosmatunisah Ali

    2011-01-01

    Background: Psychometrically sound measurement instrument is a fundamental requirement across broad range of research areas. In negative affect research, Depression Anxiety Stress Scale (DASS) has been identified as a psychometrically sound instrument to measure depression, anxiety and stress, especially the 21-item version. However, its psychometric properties in adolescents have been less consistent. Objectives: Thus, the present study sought to examine the factorial validity and internal c...

  13. Interventions to reduce postpartum stress in first-time mothers: a randomized-controlled trial.

    Science.gov (United States)

    Osman, Hibah; Saliba, Matilda; Chaaya, Monique; Naasan, Georges

    2014-10-15

    The postpartum period can be a challenging time particularly for first-time mothers. This study aimed to assess two different interventions designed to reduce stress in the postpartum among first-time mothers. Healthy first-time mothers with healthy newborns were recruited from hospitals in Beirut, Lebanon after delivery. The two interventions were a 20-minute film addressing common stressors in the postpartum period and a 24-hour telephone support hotline. Participants were randomized to one of four study arms to receive either the postpartum support film, the hotline service, both interventions, or a music CD (control). Participants were interviewed at eight to twelve weeks postpartum for assessment of levels of stress as measured by the Cohen Perceived Stress Scale (PSS-10). Of the 632 eligible women, 552 (88%) agreed to participate in the study. Of those, 452 (82%) completed the study. Mean PSS-10 scores of mothers who received the film alone (15.76) or the film with the hotline service (15.86) were significantly lower than that of the control group (18.93) (p-value film and the 24-hour telephone hotline service reduced stress in the postpartum period in first-time mothers. These simple interventions can be easily implemented and could have an important impact on the mental wellbeing of new mothers. The trial was registered with clinicaltrials.gov (identifier # NCT00857051) on March 5, 2009.

  14. New moment magnitude scale, evidence of stress drop magnitude scaling and stochastic ground motion model for the French West Indies

    Science.gov (United States)

    Drouet, Stéphane; Bouin, Marie-Paule; Cotton, Fabrice

    2011-12-01

    In this study we analyse records from the 'Les Saintes' seismic sequence following the Mw= 6.3 earthquake of 2004 November 11, which occurred close to Guadeloupe (French West Indies). 485 earthquakes with magnitudes from 2 to 6, recorded at distances between 5 and 150 km are used. S-waves Fourier spectra are analysed to simultaneously determine source, path and site terms. The results show that the duration magnitude routinely estimated for the events that occurred in the region underestimate moment magnitude by 0.5 magnitude units over the whole magnitude range. From the inverted seismic moments and corner frequencies, we compute Brune's stress drops. We show that stress drops increase with increasing magnitude. The same pattern is observed on apparent stresses (i.e. the seismic energy-to-moment ratio). However, the rate of increase diminishes at high magnitudes, which is consistent with a constant stress drop model for large events. Using the results of the inversions, we perform ground motion simulations for the entire data set using the SMSIM stochastic simulation tool. The results show that a good fit (σ= 0.25) with observed data is achieved when the source is properly described by its moment magnitude and stress drop, and when site effects are taken into account. Although the magnitude-dependent stress drop model is giving better results than the constant stress drop model, the interevent variability remains high, which could suggest that stress drop depends on other parameters such as the depth of the hypocentre. In any case, the overall variability is of the same order of magnitude as usually observed in empirical ground motion prediction equations.

  15. [The scale and application of the norm of occupational stress on the professionals in Chengdu and Chongqing area].

    Science.gov (United States)

    Zeng, Fan-Hua; Wang, Zhi-Ming; Wang, Mian-Zhen; Lan, Ya-Jia

    2004-12-01

    To establish the scale of the norm of occupational stress on the professionals and put it into practice. T scores were linear transformations of raw scores, derived to have a mean of 50 and a standard deviation of 10. The scale standard of the norm was formulated in line with the principle of normal distribution. (1) For the occupational role questionnaire (ORQ) and personal strain questionnaire (PSQ) scales, high scores suggested significant levels of occupational stress and psychological strain, respectively. T scores >/= 70 indicated a strong probability of maladaptive stress, debilitating strain, or both. T scores in 60 approximately 69 suggested mild levels of maladaptive stress and strain, and in 40 approximately 59 were within one standard deviation of the mean and should be interpreted as being within normal range. T scores /= 60) indicated increasingly strong coping resources. (2) This study provided raw score to T-score conversion tables for each OSI-R scale for the total normative sample as well as for gender, and several occupational groups, including professional engineer, professional health care, economic business, financial business, law, education and news. OSI-R profile forms for total normative samples, gender and occupation were also offered according to the conversion tables. The norm of occupational stress can be used as screening tool, organizational/occupational assessment, guide to occupational choice and intervention measures.

  16. Chronic Psychological Stress Was Not Ameliorated by Omega-3 Eicosapentaenoic Acid (EPA

    Directory of Open Access Journals (Sweden)

    Joanne Bradbury

    2017-10-01

    Full Text Available Background: Chronic psychological stress and mental health disorders are endemic in Western culture where population dietary insufficiencies of omega-3 fatty acids (n-3FA from seafood have been observed.Objective: This study was designed to test for a causal relationship between one of the most active components of fish oil, eicosapentaenoic acid (EPA, and chronic psychological stress.Method: A randomized double-blind, placebo-controlled clinical trial with parallel-assignment to two groups was designed (Trial Id: ACTRN12610000404022. The interventions were four EPA-rich fish oil capsules per day, delivering 2.2 g/d EPA (and 0.44 g/d DHA, or identical placebo (low-phenolic olive oil capsules with 5% fish oil to aid blinding. The primary outcome was the between-group difference on the Perceived Stress Scale (PSS-10 after 12 weeks supplementation. An a priori power analysis determined that group sizes of 43 would provide 80% power to detect a significant between-group difference of 12.5%, at α = 0.05. Ninety community members (64 females, 26 males reporting chronic work stress were recruited via public advertising in northern NSW, Australia.Results: At baseline the omega-3 index (EPA + DHA as % to total fatty acids in red blood cell membranes was 5.2% in both groups (SD = 1.6% control group; 1.8% active group. After supplementation this remained stable at 5.3% (SD = 1.6% for the control group but increased to 8.9% (SD = 1.5% for the active group, demonstrating successful incorporation of EPA into cells. Intention-to-treat (ITT analysis found no significant between-group differences in PSS outcome scores post-intervention (b = 1.21, p = 0.30 after adjusting for sex (b = 2.36, p = 0.079, baseline PSS (b = 0.42, p = 0.001 and baseline logEPA [b = 1.41, p = 0.185; F(3, 86 = 8.47, p < 0.01, n = 89, R-square = 0.243].Discussion: Treatment increased cell membrane EPA but, contrary to the hypothesis, there was no effect on perceived stress. Limitations

  17. Fabrication of water-dispersible and highly conductive PSS-doped PANI/graphene nanocomposites using a high-molecular weight PSS dopant and their application in H2S detection

    Science.gov (United States)

    Cho, Sunghun; Lee, Jun Seop; Jun, Jaemoon; Kim, Sung Gun; Jang, Jyongsik

    2014-11-01

    This work describes the fabrication of poly(4-styrenesulfonic acid)-doped polyaniline/graphene (PSS-doped PANI/graphene) nanocomposites and their use as sensing elements for hydrogen sulfide (H2S) detection. PSS with a weight-average molecular weight (Mw) of 1.96 × 106 was synthesized using low-temperature free-radical polymerization. The PSS was used as both a doping agent and a binding agent for the polymerization of aniline monomers in a biphasic system (water-chloroform) at -50 °C. The high Mw of PSS resulted in relatively large particle sizes and smooth surfaces of the PSS-doped PANI. These physical characteristics, in turn, resulted in low interparticle resistance and high conductivity. In addition, the PSS allowed homogeneous dispersion of reduced graphene sheets through electrostatic repulsion. The prepared PSS-doped PANI/graphene solutions showed good compatibility with flexible poly(ethylene terephthalate) (PET) substrates, making them suitable for flexible sensor electrodes. Changes in the charge-transport properties, such as protonation level, conjugation length, crystalline structure, and charge-transfer resistance, of the electrode materials were the main factors influencing the electrical and sensor performance of the PSS-doped PANI-based electrodes. PSS-doped PANI/graphene composites containing 30 wt% graphene showed the highest conductivity (168.4 S cm-1) and the lowest minimum detection level (MDL) for H2S gas (1 ppm). This result is consistent with the observed improvements in charge transport in the electrode materials via strong π-π stacking interactions between the PANI and the graphene sheets.This work describes the fabrication of poly(4-styrenesulfonic acid)-doped polyaniline/graphene (PSS-doped PANI/graphene) nanocomposites and their use as sensing elements for hydrogen sulfide (H2S) detection. PSS with a weight-average molecular weight (Mw) of 1.96 × 106 was synthesized using low-temperature free-radical polymerization. The PSS was

  18. Perceived Stress and Professional Quality of Life in Neonatal Intensive Care Unit Nurses in Gujarat, India.

    Science.gov (United States)

    Amin, Amee A; Vankar, Jagdish R; Nimbalkar, Somashekhar M; Phatak, Ajay G

    2015-11-01

    To study the levels of perceived stress in Neonatal Intensive Care Unit (NICU) nurses and its association with professional quality of life domains viz. compassion satisfaction, burnout and secondary trauma. In this multicenter, cross sectional study, data was collected by surveying 129 nurses from nine NICUs across six cities of Gujarat, India using demographic questionnaire, Perceived Stress Scale (PSS14) and Professional Quality of Life Scale (ProQOL5) during July to September 2013. Descriptive statistics, correlation coefficient and multiple regression were used for analysis. The mean (SD) age of participants was 28.37 (8.20) y. Most were single, satisfied with salary benefits and reported 'good' to 'excellent' relationships at work. The mean (SD) duration of duty hours was 8.12 (0.76) h and 43.6% were attending to more than 4 patients/shift. The mean (SD) perceived stress level was 22.19 (7.17) [Range: 3 to 39]. High compassion satisfaction, high burnout, and high secondary traumatic stress were reported by 25 (19.4%), 30 (23.3%) and 30 (23.3%) nurses respectively. PSS14 was negatively correlated with compassion satisfaction (r = -0.28) and positively correlated with burnout (r = 0.43) and secondary traumatic stress (r = 0.24). Most of the nurses (91, 70.5%) were identified as perceiving moderate to high stress. Professional quality of life domains correlated with perceived stress. There is further need to study domains influencing NICU nurses' professional QOL. Identifying stress and QOL issues in NICU nurses can help formulate relevant policies.

  19. Enhanced thermoelectric properties of PEDOT/PSS/Te composite films treated with H{sub 2}SO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Song, Haijun; Cai, Kefeng, E-mail: kfcai@tongji.edu.cn [Tongji University, Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, School of Materials Science and Engineering (China); Shen, Shirley [CSIRO Manufacturing (Australia)

    2016-12-15

    Firstly, tellurium (Te) nanorods with a high Seebeck coefficient have been integrated into a conducting polymer PEDOT/PSS to form PEDOT/PSS/Te composite films. The Seebeck coefficient of the PEDOT/PSS/Te (90 wt.%) composite films is ~191 μV/K, which is about 13 times greater than that of pristine PEDOT/PSS. Then, H{sub 2}SO{sub 4} treatment has been used to further tune the thermoelectric properties of the composite films by adjusting the doping level and increasing the carrier concentration. After the acid treatment, the electrical conductivity of the composite films has increased from 0.22 to 1613 S/cm due to the removal of insulating PSS and the structural rearrangement of PEDOT. An optimized power factor of 42.1 μW/mK{sup 2} has been obtained at room temperature for a PEDOT/PSS/Te (80 wt.%) sample, which is about ten times larger than that of the untreated PEDOT/PSS/Te composite film.

  20. A mindfulness training program based on brief practices (M-PBI) to reduce stress in the workplace: a randomised controlled pilot study.

    Science.gov (United States)

    Arredondo, M; Sabaté, M; Valveny, N; Langa, M; Dosantos, R; Moreno, J; Botella, L

    2017-01-01

    Work stress is a major contributor to absenteeism and reduced work productivity. A randomised and controlled study in employee-volunteers (with Perceived Stress Scale [PSS-14]>22) was performed to assess a mindfulness program based on brief integrated mindfulness practices (M-PBI) with the aim of reducing stress in the workplace. The PSS-14 of the employees before and after 8-weeks M-PBI program, as well as after a 20-week follow-up, was assessed (primary endpoint). The employees also carried the following questionnaires (secondary endpoints): Five Facet Mindfulness Questionnaire (FFMQ), Self-Compassion Scale (SCS), Experiences Questionnaire-Decentering (EQ-D), and Maslach Burnout Inventory-General Survey (MBI-GS). Heart Rate Variability (HRV) was measured during each session in a subgroup of employees (n = 10) of the interventional group randomly selected. A total of 40 employees (77.5% female median [SD] age of 36.6 [5.6] years) took part in this study: 21 and 19 in the intervention and control group, respectively. No differences in baseline characteristics were encountered between the groups. Results show a significant decrease in stress and increase in mindfulness over time in the intervention group (PSS-14 and FFMQ; p < 0.05 both). Additionally, an improvement in decentering (EQ-D), self-compassion (SCS) and burnout (MBI-GS) were also observed compared to the control group (p < 0.05 in all). HRV measurement also showed an improvement. In conclusion, a brief practices, 8-weeks M-BIP program is an effective tool to quickly reduce stress and improve well-being in a workplace.

  1. NiS(NPs)-PEDOT-PSS composite counter electrode for a high efficiency dye sensitized solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Maiaugree, Wasan [Integrated Nanotechnology Research Center, Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Center for Alternative Energy Research and Development, Khon Kaen University, Khon Kaen 40002 (Thailand); Pimparue, Pachara; Jarernboon, Wirat [Integrated Nanotechnology Research Center, Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Pimanpang, Samuk [Department of Physics, Faculty of Science, Srinakharinwirot University, Bangkok 10110 (Thailand); Amornkitbamrung, Vittaya [Integrated Nanotechnology Research Center, Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Swatsitang, Ekaphan, E-mail: ekaphan@kku.ac.th [Integrated Nanotechnology Research Center, Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Center for Alternative Energy Research and Development, Khon Kaen University, Khon Kaen 40002 (Thailand)

    2017-06-15

    Graphical abstract: Figure(a) and (b) represent models depict PEDOT-PSS counter electrodes of DSSC without and with NiS NPs modification, respectively. The active surface area of PEDOT-PSS polymer can be improved by combining with NiS(NPs). The I-V curves in figure (c) show the superior photovoltaic conversion efficiency of 8.18% for NiS(NPs)/PEDOT-PSS DSSC. - Highlights: • Active surface area of PEDOT-PSS CE can be improved by mixing with NiS(NPs). • Electrocatalytic activity of mixed NiS(NPs)/PEDOT-PSS polymer is also improved. • NiS(NPs)/PEDOT-PSS CE shows a very low charge transfer resistance of 0.46 Ω. • In this work, the high photovoltaic conversion efficiency of 8.18% is achieved. - Abstract: Nickel sulfide (NiS) nanoparticles (NPs) (NiS(NPs)) were prepared by the hydrothermal method. X-ray diffraction (XRD) results indicate the hexagonal structure of NiS(NPs). SEM micrographs reveal the agglomeration of irregular hexagonal – shaped NiS(NPs) with estimated particle size in the range of 50–150 nm. Counter electrodes (CEs) of dye-sensitized solar cells (DSSCs) were prepared by coating the composite slurry of different NiS(NPs) loadings and Poly (3, 4-Ethylendioxythiophene) – Poly (Styrene Sulfonate) (PEDOT-PSS) on fluoride-doped tin oxide (FTO) substrates using a doctor blading technique. Cyclic voltammetry (CV) results indicate that the composites of NiS(NPs) and PEDOT-PSS (NiS(NPs)/PEDOT-PSS) films could function as a catalyst for I{sub 3}{sup −} reduction with a maximum cell efficiency of 8.18% for a cell of 0.3 g NiS(NPs) loading.

  2. Cross-Culture Validation of the HIV/AIDS Stress Scale: The Development of a Revised Chinese Version.

    Science.gov (United States)

    Niu, Lu; Qiu, Yangyang; Luo, Dan; Chen, Xi; Wang, Min; Pakenham, Kenneth I; Zhang, Xixing; Huang, Zhulin; Xiao, Shuiyuan

    2016-01-01

    Being HIV-infected is a stressful experience for many individuals. To assess HIV-related stress in the Chinese context, a measure with satisfied psychometric properties is yet underdeveloped. This study aimed to examine the psychometric characteristics of a simplified Chinese version of the HIV/AIDS Stress Scale (SS-HIV) among people living with HIV/AIDS in central China. A total of 667 people living with HIV (92% were male) were recruited from March 1st 2014 to August 31th 2015 by consecutive sampling. A standard questionnaire package containing the Chinese HIV/AIDS Stress Scale (CSS-HIV), the Chinese Patient Health Questionnaire-9 (PHQ-9), and the Chinese Generalized Anxiety Disorder Scale (GAD-7) were administered to all participants, and 38 of the participants were selected randomly to be re-tested in four weeks after the initial testing. Our data supported that a revised 17-item CSS-HIV had adequate psychometric properties. It consisted of 3 factors: emotional stress (6 items), social stress (6 items) and instrumental stress (5 items). The overall Cronbach's α was 0.906, and the test-retest reliability coefficient was 0.832. The revised CSS-HIV was significantly correlated with the number of HIV-related symptoms, as well as scores on the PHQ-9 and GAD-7, indicating acceptable concurrent validity. The 17-item Chinese version of the SS-HIV has potential research and clinical utility in identifying important stressors among the Chinese HIV-infected population and in understanding the effects of stress on adjustment to HIV.

  3. Organismal climatology: analyzing environmental variability at scales relevant to physiological stress.

    Science.gov (United States)

    Helmuth, Brian; Broitman, Bernardo R; Yamane, Lauren; Gilman, Sarah E; Mach, Katharine; Mislan, K A S; Denny, Mark W

    2010-03-15

    Predicting when, where and with what magnitude climate change is likely to affect the fitness, abundance and distribution of organisms and the functioning of ecosystems has emerged as a high priority for scientists and resource managers. However, even in cases where we have detailed knowledge of current species' range boundaries, we often do not understand what, if any, aspects of weather and climate act to set these limits. This shortcoming significantly curtails our capacity to predict potential future range shifts in response to climate change, especially since the factors that set range boundaries under those novel conditions may be different from those that set limits today. We quantitatively examine a nine-year time series of temperature records relevant to the body temperatures of intertidal mussels as measured using biomimetic sensors. Specifically, we explore how a 'climatology' of body temperatures, as opposed to long-term records of habitat-level parameters such as air and water temperatures, can be used to extrapolate meaningful spatial and temporal patterns of physiological stress. Using different metrics that correspond to various aspects of physiological stress (seasonal means, cumulative temperature and the return time of extremes) we show that these potential environmental stressors do not always occur in synchrony with one another. Our analysis also shows that patterns of animal temperature are not well correlated with simple, commonly used metrics such as air temperature. Detailed physiological studies can provide guidance to predicting the effects of global climate change on natural ecosystems but only if we concomitantly record, archive and model environmental signals at appropriate scales.

  4. Development and validation of a Thai stressful life events rating scale for patients with a diagnosis of schizophrenic methamphetamine abuse

    OpenAIRE

    Ek-uma Imkome; JintanaYunibhand; Waraporn Chaiyawat

    2017-01-01

    This study aimed to psychometrically test a Thai Stressful Life Events Rating Scale (TSLERS). Factor analysis was done on data collected from 313 patients with schizophrenia and methamphetamine abuse in Thailand from April to May, 2015. Results identified the following problems impacting physical and mental health: social relationship and social concerns, money, family life, life security, and career. Evaluation of the psychometric scale properties demonstrated acceptable validity ...

  5. Residual stress relaxation measurements across interfaces at macro-and micro-scales using slitting and DIC

    Energy Technology Data Exchange (ETDEWEB)

    Blair, A; Daynes, N; Hamilton, D; Horne, G; Hodgson, D Z L; Shterenlikht, A [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR (United Kingdom); Heard, P J; Scott, T B, E-mail: mexas@bristol.ac.u [Interface Analysis Centre, University of Bristol, Bristol BS2 8BS (United Kingdom)

    2009-08-01

    In this paper digital image correlation is used to measure relaxation of residual stresses across an interface. On the macro scale the method is applied to a tri-layer bonded aluminium sample, where the middle layer is in tension and the top and the bottom layers are in compression. High contrast speckle pattern was sprayed onto the surface. The relaxation was done with the slitting saw. Three dimensional image correlation was used. On the micro scale the technique was applied to a heat treated large grain brass loaded in tension. Mechanical and electro polishing was used for surface preparation. A focused ion beam was used for slitting across a grain boundary and for imaging. Grain orientation was measured using electron back-scattering diffraction. Two dimensional image correlation was employed. In all macro- and micro-scale experiments the range of measured relaxation was sub-pixel, almost at the limit of the resolution of the image correlation algorithms. In the macro-scale experiments, the limiting factor was low residual stress, due to low shear strength of the Araldite glue used for bonding. Finite element simulation of the relaxation agreed only qualitatively with the experimental results at both size scales. The methodology is intended for use with inverse methods, i.e. the measured relaxation is applied as the boundary conditions to an appropriate FE model which produces stresses equal to the relaxed residual stresses, but with opposite sign. The main conclusion is that the digital image correlation method could be used to measure relaxation caused by slitting in heterogeneous materials and structures at both macro- and micro-scales. However, the repeatability of the techniques needs to be improved before residual stresses can be determined confidently. Acknowledgments The authors gratefully acknowledge Airbus UK for provision of materials. They thank Dr Richard Burguete, Airbus UK, and Prof Peter Flewitt, Department of Physics, University of Bristol, for

  6. Residual stress relaxation measurements across interfaces at macro-and micro-scales using slitting and DIC

    International Nuclear Information System (INIS)

    Blair, A; Daynes, N; Hamilton, D; Horne, G; Hodgson, D Z L; Shterenlikht, A; Heard, P J; Scott, T B

    2009-01-01

    In this paper digital image correlation is used to measure relaxation of residual stresses across an interface. On the macro scale the method is applied to a tri-layer bonded aluminium sample, where the middle layer is in tension and the top and the bottom layers are in compression. High contrast speckle pattern was sprayed onto the surface. The relaxation was done with the slitting saw. Three dimensional image correlation was used. On the micro scale the technique was applied to a heat treated large grain brass loaded in tension. Mechanical and electro polishing was used for surface preparation. A focused ion beam was used for slitting across a grain boundary and for imaging. Grain orientation was measured using electron back-scattering diffraction. Two dimensional image correlation was employed. In all macro- and micro-scale experiments the range of measured relaxation was sub-pixel, almost at the limit of the resolution of the image correlation algorithms. In the macro-scale experiments, the limiting factor was low residual stress, due to low shear strength of the Araldite glue used for bonding. Finite element simulation of the relaxation agreed only qualitatively with the experimental results at both size scales. The methodology is intended for use with inverse methods, i.e. the measured relaxation is applied as the boundary conditions to an appropriate FE model which produces stresses equal to the relaxed residual stresses, but with opposite sign. The main conclusion is that the digital image correlation method could be used to measure relaxation caused by slitting in heterogeneous materials and structures at both macro- and micro-scales. However, the repeatability of the techniques needs to be improved before residual stresses can be determined confidently. Acknowledgments The authors gratefully acknowledge Airbus UK for provision of materials. They thank Dr Richard Burguete, Airbus UK, and Prof Peter Flewitt, Department of Physics, University of Bristol, for

  7. Spatio-temporal characteristics of large scale motions in a turbulent boundary layer from direct wall shear stress measurement

    Science.gov (United States)

    Pabon, Rommel; Barnard, Casey; Ukeiley, Lawrence; Sheplak, Mark

    2016-11-01

    Particle image velocimetry (PIV) and fluctuating wall shear stress experiments were performed on a flat plate turbulent boundary layer (TBL) under zero pressure gradient conditions. The fluctuating wall shear stress was measured using a microelectromechanical 1mm × 1mm floating element capacitive shear stress sensor (CSSS) developed at the University of Florida. The experiments elucidated the imprint of the organized motions in a TBL on the wall shear stress through its direct measurement. Spatial autocorrelation of the streamwise velocity from the PIV snapshots revealed large scale motions that scale on the order of boundary layer thickness. However, the captured inclination angle was lower than that determined using the classic method by means of wall shear stress and hot-wire anemometry (HWA) temporal cross-correlations and a frozen field hypothesis using a convection velocity. The current study suggests the large size of these motions begins to degrade the applicability of the frozen field hypothesis for the time resolved HWA experiments. The simultaneous PIV and CSSS measurements are also used for spatial reconstruction of the velocity field during conditionally sampled intense wall shear stress events. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1315138.

  8. Development of Kossel micro-diffraction for strain and stress analysis at the micrometer scale: applications to crystalline materials

    International Nuclear Information System (INIS)

    Bouscaud, D.

    2012-01-01

    X-ray diffraction is a non-destructive method frequently used in materials science to analyse the stress state at a macroscopic scale. Due to the growing complexity of new materials and their applications, it is necessary to know the strain and stress state at a lower scale. Thus, a Kossel micro-diffraction experimental set-up was developed inside a scanning electron microscope. It allows to obtain the crystallographic orientation as well as the strains and stresses within a volume of a few cubic micrometers. Some experiments were also performed using a synchrotron radiation. An experimental procedure was developed to optimize the acquisition of Kossel line patterns and their post-processing. The stress calculation from Kossel patterns was validated by comparing the stress state of single crystals during in situ mechanical loading, obtained by Kossel micro-diffraction and with classical diffraction methods. Then Kossel micro-diffraction was applied to polycrystalline samples by gradually decreasing the grain size. Intergranular stress heterogeneities were for example measured in an interstitial-free steel. Experiments were finally carried out in thin layer samples representative of microelectronic components. (author)

  9. The Short Version of the Depression Anxiety Stress Scales (DASS-21): Factor Structure in a Young Adolescent Sample

    Science.gov (United States)

    Szabo, Marianna

    2010-01-01

    This study explored the factor structure of the short form of the Depression Anxiety Stress Scales (DASS-21; Lovibond & Lovibond, 1995b) in a young adolescent sample. A group of 484 high school students ("Mean" age = 13.62 years, Min = 11.83, Max = 15.67 years, 52 % boys) completed the DASS-21. Several models were tested using Confirmatory Factor…

  10. Hybrid organic/inorganic position-sensitive detectors based on PEDOT:PSS/n-Si

    Science.gov (United States)

    Javadi, Mohammad; Gholami, Mahdiyeh; Torbatiyan, Hadis; Abdi, Yaser

    2018-03-01

    Various configurations like p-n junctions, metal-semiconductor Schottky barriers, and metal-oxide-semiconductor structures have been widely used in position-sensitive detectors. In this report, we propose a PEDOT:PSS/n-Si heterojunction as a hybrid organic/inorganic configuration for position-sensitive detectors. The influence of the thickness of the PEDOT:PSS layer, the wavelength of incident light, and the intensity of illumination on the device performance are investigated. The hybrid PSD exhibits very high sensitivity (>100 mV/mm), excellent nonlinearity (0.995) with a response time of heterojunction are very promising for developing a new class of position-sensitive detectors based on the hybrid organic/inorganic junctions.

  11. Relation between secondary doping and phase separation in PEDOT:PSS films

    Energy Technology Data Exchange (ETDEWEB)

    Donoval, Martin; Micjan, Michal; Novota, Miroslav; Nevrela, Juraj; Kovacova, Sona; Pavuk, Milan; Juhasz, Peter; Jagelka, Martin; Kovac, Jaroslav; Jakabovic, Jan [Institute of Electronics and Photonics, Slovak University of Technology, Ilkovičova 3, Bratislava 81219 (Slovakia); Cigan, Marek [Institute of Chemistry, Faculty of Natural Science, Comenius University, Mlynska dolina CH-2, Ilkovicova 6, Bratislava 84215 (Slovakia); Weis, Martin, E-mail: martin.weis@stuba.sk [Institute of Electronics and Photonics, Slovak University of Technology, Ilkovičova 3, Bratislava 81219 (Slovakia)

    2017-02-15

    Highlights: • Surface morphology of highly conductive polymer was investigated. • Phase separation due to secondary doping is an origin of conductivity enhancement. • Phase separation is not dependent on secondary dopant type. - Abstract: Conductive copolymer poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) has been proposed as an alternative to transparent conductive oxides because of its flexibility, transparency, and low-cost production. Four different secondary dopants, namely N,N-dimethylformamide, ethyleneglycol, sorbitol, and dimethyl sulfoxide, have been used to improve the conductivity. The relation between the structure changes and conductivity enhancement is studied in detail. Atomic force microscopy study of the thin film surface reveals the phase separation of PEDOT and PSS. We demonstrate that secondary doping induces the phase separation as well as the conductivity enhancement.

  12. MnO2-Graphene Oxide-PEDOT:PSS Nanocomposite for an Electrochemical Supercapacitor

    Science.gov (United States)

    Patil, Dipali S.; Pawar, Sachin A.; Shin, Jae Cheol; Kim, Hyo Jin

    2018-04-01

    A ternary nanocomposite with poly (3,4 ethylene dioxythiophene:poly(styrene sulfonate) (PEDOT:PSS)-MnO2 nanowires-graphene oxide (PMn-GO) was synthesized by using simple chemical route. The formation of the nanocomposite was analyzed by using X-ray diffraction and X-ray photoelectron spectroscopy. Field-emission scanning microscopy (FESEM) revealed the formation of MnO2 nanowires and graphene oxide nanosheets. The highest specific capacitance (areal capacitance) of 841 Fg -1 (177 mFcm -2) at 10 mVs -1 and energy density of 0.593 kWhkg -1 at 0.5 mA were observed for PMn-GO, indicating a constructive synergistic effect of PEDOT:PSS, MnO2 nanowires and graphene oxide. The achieved promising electrochemical characteristics showed that this ternary nanocomposite is a good alternative as an electrode material for supercapacitor.

  13. Silver Nanowires Modified with PEDOT: PSS and Graphene for Organic Light-Emitting Diodes Anode.

    Science.gov (United States)

    Xu, Yilin; Wei, Xiang; Wang, Cong; Cao, Jin; Chen, Yigang; Ma, Zhongquan; You, Ying; Wan, Jixiang; Fang, Xiaohong; Chen, Xiaoyuan

    2017-03-28

    Silver nanowires (AgNWs) networks are promising candidates for the replacement of indium tin oxide (ITO). However, the surface roughness of the AgNWs network is still too high for its application in optoelectronic devices. In this work, we have reduced the surface roughness of the AgNWs networks to 6.4 nm, compared to 33.9 nm of the as-deposited AgNWs network through the hot-pressing process, treatment with poly (3,4ethylenedioxythiophene)-poly (styrenesulfanate), and covered with graphene films. Using this method, we are able to produce AgNWs/PEDOT: PSS/SLG composite films with the transmittance and sheet resistance of 88.29% and 30 Ω/□, respectively. The OLEDs based on the AgNWs/PEDOT: PSS/SLG anodes are comparable to those based on ITO anodes.

  14. Bringing service design to manufacturing companies: integrating PSS and service design approaches

    DEFF Research Database (Denmark)

    Costa, Nina; Patrício, Lia; Morelli, Nicola

    2018-01-01

    in a manufacturing industry. This paper details how the application supports the design of product–service system solutions from the exploration to the implementation stages, highlighting the physical evidence of service, and contributes to advance design research at the intersection of PSS and Service Design.......Manufacturing companies increasingly try to innovate in their offers to consumers by creating more complete solutions that combine product and service components. However, shifting from a product-centric perspective to a solution-oriented perspective is challenging. The present study adopted...... a design research methodology and built on Service-Dominant logic, integrating the human-oriented perspective of Service Design with an organizational network-oriented perspective of Product–Service System. It creates a new Integrative PSS approach, evolves design models, and provides an application...

  15. A framework for conceptualisation of PSS solutions: On network-based development models

    DEFF Research Database (Denmark)

    Mougaard, Krestine

    of the Danish Innovation Consortium PROTEUS (PRoduct-service/system-Tools to Ensure User centred Services), was carried out at the Technical University of Denmark at the Section of Engineering Design and Product Development. The project’s aim was to investigate how to support the Danish maritime industry...... in this upheaval and change towards a new mode of business- and product development. The research presented in this thesis is based on action-research, involving all ten companies participating in the PROTEUS consortium, plus a comparative case study of MAN PrimeServ Frederikshavn and Alfa Laval Aalborg. The main...... and verified in case companies.Three new PSS tools to support PSS conceptualisation. Contributions to the PROTEUS Workbook series – communicating the results of the PROTEUS research consortium to both academics and industry practitioners....

  16. Planar silver nanowire, carbon nanotube and PEDOT:PSS nanocomposite transparent electrodes

    Science.gov (United States)

    Stapleton, Andrew J.; Yambem, Soniya D.; Johns, Ashley H.; Afre, Rakesh A.; Ellis, Amanda V.; Shapter, Joe G.; Andersson, Gunther G.; Quinton, Jamie S.; Burn, Paul L.; Meredith, Paul; Lewis, David A.

    2015-04-01

    Highly conductive, transparent and flexible planar electrodes were fabricated using interwoven silver nanowires and single-walled carbon nanotubes (AgNW:SWCNT) in a PEDOT:PSS matrix via an epoxy transfer method from a silicon template. The planar electrodes achieved a sheet resistance of 6.6 ± 0.0 Ω/□ and an average transmission of 86% between 400 and 800 nm. A high figure of merit of 367 Ω-1 is reported for the electrodes, which is much higher than that measured for indium tin oxide and reported for other AgNW composites. The AgNW:SWCNT:PEDOT:PSS electrode was used to fabricate low temperature (annealing free) devices demonstrating their potential to function with a range of organic semiconducting polymer:fullerene bulk heterojunction blend systems.

  17. Revisiting PSS and service design in the light of the SD-logic

    DEFF Research Database (Denmark)

    Costa, Nina; Patrício, Lia; Morelli, Nicola

    2016-01-01

    are only means to an end. Also, different approaches, methods and tools have been developed to design value propositions however they still lack to explicit the SDlogic principles. The design of solutions that provide value-in-use is at the centre of both Product Service System (PSS) approach and service...... comprehensive discussion about these two approaches and proposes a conceptual framework for integrating PSS organizational point of view; and SD human-centred focus to design better service.......Researchers and practitioners have increasingly recognized the importance of offering value propositions to customers that enable value co-creation as discussed in the service dominant logic (SD-logic). SD-logic recognizes customers as active co-creators and posits that products and services...

  18. The Border Community & Immigration Stress Scale: A Preliminary Examination of a Community Responsive Measure in Two Southwest Samples

    Science.gov (United States)

    Carvajal, Scott C.; Rosales, Cecilia; Rubio-Goldsmith, Raquel; Sabo, Samantha; Ingram, Maia; McClelland, Debra Jean; Redondo, Floribella; Torres, Emma; Romero, Andrea J.; Oleary, Anna Ochoa; Sanchez, Zoila; de Zapien, Jill Guernsey

    2015-01-01

    Background Understanding contemporary socio-cultural stressors may assist educational, clinical and policy-level health promotion efforts. This study presents descriptive findings on a new measure, the Border Community & Immigration Stress Scale (BCISS). Methods The data were from two community surveys as part of community based participatory projects conducted in the Southwestern US border region. This scale includes stressful experiences reflected in extant measures, with new items reflecting heightened local migration pressures and health care barriers. Results Stressors representing each main domain, including novel ones, were reported with frequency and at high intensity in the predominantly Mexican-descent samples. Total stress was also significantly associated with mental and physical health indicators. Discussion The study suggests particularly high health burdens tied to the experience of stressors in the US border region. Further, many of the stressors are also likely relevant for other communities within developed nations also experiencing high levels of migration. PMID:22430894

  19. Prevalence and association of perceived stress, substance use and behavioral addictions: a cross-sectional study among university students in France, 2009-2011.

    Science.gov (United States)

    Tavolacci, Marie Pierre; Ladner, Joel; Grigioni, Sebastien; Richard, Laure; Villet, Herve; Dechelotte, Pierre

    2013-08-06

    University students face multiple stressors such as academic overload, constant pressure to succeed, competition with peers as well as concerns about the future. Stress should not be considered on its own, but should be associated with potential risk behaviors leading to onset of substance use and related problems heightened during the university period. The aim of this study was to determine the prevalence of main substance use and behavioral addictions among students in higher education in France and to examine the relationship with perceived stress. A self-administered questionnaire was filled out by university student volunteers from Upper Normandy (France) either by anonymous online questionnaire or by paper questionnaire. Data collected included socio-economic characteristics, Perceived Stress Scale (PSS), substance use (tobacco, alcohol, and cannabis) and hazardous behaviors: alcohol abuse problems, smoking, consumption of cannabis, eating disorders, and cyber addiction. A total of 1876 students were included. Mean PSS score was 15.9 (standard deviation = 7.2). Highly stressed students (4th quartile) were compared with lesser stressed students (1st quartile). A positive relation was observed between female gender, regular smokers, alcohol abuse problems, risk of cyberaddiction and especially eating disorders (AOR = 5.45, 95% CI = 3.42-8.69), and increasing PSS score. PSS score however, was not significantly related to the curriculum, regular alcohol use, drunkenness or binge drinking even after additional controlling for use of other substances. We found a significant negative association between stress and practice of sport: students with the most physical activity were less likely to report perceived stress (4th quartile: AOR = 0.57, 95% CI = 0.39-0.80). This cross-sectional study among university students in France revealed that perceived stress was associated not only with known risks such as alcohol misuse, but also with new risks

  20. Functional solid additive modified PEDOT:PSS as an anode buffer layer for enhanced photovoltaic performance and stability in polymer solar cells

    Science.gov (United States)

    Xu, Binrui; Gopalan, Sai-Anand; Gopalan, Anantha-Iyengar; Muthuchamy, Nallal; Lee, Kwang-Pill; Lee, Jae-Sung; Jiang, Yu; Lee, Sang-Won; Kim, Sae-Wan; Kim, Ju-Seong; Jeong, Hyun-Min; Kwon, Jin-Beon; Bae, Jin-Hyuk; Kang, Shin-Won

    2017-01-01

    Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is most commonly used as an anode buffer layer in bulk-heterojunction (BHJ) polymer solar cells (PSCs). However, its hygroscopic and acidic nature contributes to the insufficient electrical conductivity, air stability and restricted photovoltaic (PV) performance for the fabricated PSCs. In this study, a new multifunctional additive, 2,3-dihydroxypyridine (DOH), has been used in the PEDOT: PSS buffer layer to obtain modified properties for PEDOT: PSS@DOH and achieve high PV performances. The electrical conductivity of PEDOT:PSS@DOH films was markedly improved compared with that of PEDOT:PSS. The PEDOT:PSS@DOH film exhibited excellent optical characteristics, appropriate work function alignment, and good surface properties in BHJ-PSCs. When a poly(3-hexylthiohpene):[6,6]-phenyl C61-butyric acid methyl ester blend system was applied as the photoactive layer, the power conversion efficiency of the resulting PSCs with PEDOT:PSS@DOH(1.0%) reached 3.49%, outperforming pristine PEDOT:PSS, exhibiting a power conversion enhancement of 20%. The device fabricated using PEDOT:PSS@DOH (1.0 wt%) also exhibited improved thermal and air stability. Our results also confirm that DOH, a basic pyridine derivative, facilitates adequate hydrogen bonding interactions with the sulfonic acid groups of PSS, induces the conformational transformation of PEDOT chains and contributes to the phase separation between PEDOT and PSS chains. PMID:28338088

  1. The Bahasa Melayu version of the Nursing Stress Scale among nurses: a reliability study in Malaysia.

    Science.gov (United States)

    Rosnawati, Muhamad Robat; Moe, Htay; Masilamani, Retneswari; Darus, A

    2010-10-01

    The Nursing Stress Scale (NSS) has been shown to be a valid and reliable instrument to assess occupational stressors among nurses. The NSS, which was previously used in the English version, was translated and back-translated into Bahasa Melayu. This study was conducted to assess the reliability of the Bahasa Melayu version of the NSS among nurses for future studies in this country. The reliability of the NSS was assessed after its readministration to 30 nurses with a 2-week interval. The Spearman coefficient was calculated to assess its stability. The internal consistency was measured through 4 measures: Cronbach's α, Spearman-Brown, Guttman split-half, and standardized item α coefficients. The total response rate was 70%. Test-retest reliability showed remarkable stability (Spearman's ρ exceeded .70). All 4 measures of internal consistency among items indicated a satisfactory level (coefficients in the range of .68 to .87). In conclusion, the Bahasa Melayu version of the NSS is a reliable and useful instrument for measuring the possible stressors at the workplace among nurses.

  2. On the dimensionality of the stress-related growth scale: one, three, or seven factors?

    Science.gov (United States)

    Roesch, Scott C; Rowley, Anthony A; Vaughn, Allison A

    2004-06-01

    We examined the factorial validity and dimensionality of the Stress-Related Growth Scale (SRGS; Park, Cohen, & Murch, 1996) using a large multiethnic sample (n = 1,070). Exploratory and confirmatory factor analyses suggested that a multidimensional representation of the SRGS fit better than a unidimensional representation. Specifically, we cross-validated both a 3-factor model and a 7-factor model using confirmatory factor analysis and were shown to be invariant across gender and ethnic groups. The 3-factor model was represented by global dimensions of growth that included rational/mature thinking, affective/emotional growth, and religious/spiritual growth. We replicated the 7-factor model of Armeli, Gunthert, and Cohen (2001) and it represented more specific components of growth such as Self-Understanding and Treatment of Others. However, some factors of the 7-factor model had questionable internal consistency and were strongly intercorrelated, suggesting redundancy. The findings support the notion that the factor structure of both the original 1-factor and revised 7-factor models are unstable and that the 3-factor model developed in this research has more reliable psychometric properties and structure.

  3. A facile micropatterning method for a highly flexible PEDOT:PSS on SU-8

    KAUST Repository

    Cho, Nam Chul; Diekhans, Justin; Steward, Malia; Bakr, Osman; Choi, Seungkeun

    2016-01-01

    We report the micropatterning of conducting polymer on the epoxy-based photoresist to demonstrate fully organic, conducting and flexible electrodes. We show that polystyrene sulfonic acid can be covalently linked to the surface of the photoresist (SU-8) by forming sulfonyl ester at the interfaces. We also present an application of the patterned PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate)/SU-8 to the electroplating of metal electrodes. © 2016 Elsevier B.V.

  4. Electromechanical properties of polyamide/lycra fabric treated with PEDOT:PSS

    Science.gov (United States)

    Tadesse, M. G.; Mengistie, D. A.; Loghin, C.; Chen, Y.; Wang, L.; Catalin, D.; Müller, C.; Nierstrasz, V.

    2017-10-01

    One of the challenges in smart textiles is to develop suitable multifunctional materials that can address simultaneously several characteristics such as durability, stretchability, lightweight, and conductivity. Conductive polymers which showed success in different technological fields like polymer solar cells and light emitting diodes are promising in many smart textile applications. In this work, we treated a common polyamide/lycra knitted fabric with PEDOT:PSS for stretchable e-textiles. PEDOT:PSS, with DMSO as a conductivity enhancer and different ratios of water-based polyurethane dispersions as a binder, was applied to the fabric with simple immersion and coating applications. The effect of different application methods and binder ratio on the surface resistance of the fabric was monitored with four point probe electrical surface resistance measurement systems. Samples prepared by immersion technique are more uniform and have higher conductivity than those prepared by a coating technique. SEM images showed that PEDOT:PSS is incorporated into the structure in the immersion method while in the coating it is majorly present on the surface of the fabric. The tensile measurement showed that the acidic PEDOT:PSS and polyurethane dispersion coating has no adverse effect on the tensile strength of the fabric. The coated samples can be stretched up to 700% while still reasonably conductive. The resistance increases only by a small amount when samples were stretched cyclically by stretching 100%. Generally, samples prepared by the immersion method maintained better conductivity while stretching than those by a coating method. The washing fastness of the samples was also assessed.

  5. A facile micropatterning method for a highly flexible PEDOT:PSS on SU-8

    KAUST Repository

    Cho, Nam Chul

    2016-04-17

    We report the micropatterning of conducting polymer on the epoxy-based photoresist to demonstrate fully organic, conducting and flexible electrodes. We show that polystyrene sulfonic acid can be covalently linked to the surface of the photoresist (SU-8) by forming sulfonyl ester at the interfaces. We also present an application of the patterned PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate)/SU-8 to the electroplating of metal electrodes. © 2016 Elsevier B.V.

  6. Energy level alignment at C{sub 60}/DTDCTB/PEDOT:PSS interfaces in organic photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jisu; Jung, Kwanwook; Jeong, Junkyeong; Hyun, Gyeongho [Institute of Physics and Applied Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722 (Korea, Republic of); Lee, Hyunbok, E-mail: hyunbok@kangwon.ac.kr [Department of Physics, Kangwon National University, Chuncheon-si, Gangwon-do 24341 (Korea, Republic of); Yi, Yeonjin, E-mail: yeonjin@yonsei.ac.kr [Institute of Physics and Applied Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722 (Korea, Republic of)

    2017-04-30

    Highlights: • The interfacial energy level alignment of C{sub 60}/DTDCTB/PEDOT:PSS was determined via in situ UPS and IPES measurements. • A large photovoltaic gap of 1.30 eV was evaluated between the DTDCTB donor and C{sub 60} acceptor. • A low hole extraction barrier of 0.42 eV from DTDCTB to PEDOT:PSS was evaluated. • The excellent electronic properties of DTDCTB with a narrow band gap were the source of its high OPV power conversion efficiencies. - Abstract: The electronic structure of a narrow band gap small molecule ditolylaminothienyl–benzothiadiazole–dicyanovinylene (DTDCTB), possessing a donor-acceptor-acceptor configuration, was investigated with regard to its application as an efficient donor material in organic photovoltaics (OPVs). The interfacial orbital alignment of C{sub 60}/DTDCTB/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was determined using in situ ultraviolet photoelectron and inverse photoelectron spectroscopic methods. The ionization energy and electron affinity values of DTDCTB were measured to be 5.27 eV and 3.65 eV, respectively, and thus a very small transport gap of 1.62 eV was evaluated. Large band bending of DTDCTB on PEDOT:PSS was observed, resulting in a low hole extraction barrier. Additionally, the photovoltaic gap between the highest occupied molecular orbital level of the DTDCTB donor and the lowest unoccupied molecular orbital level of the C{sub 60} acceptor was estimated to be 1.30 eV, which is known to be the theoretical maximum open-circuit voltage in OPVs employing the C{sub 60}/DTDCTB active layer. The unique electronic structures of DTDCTB contributed toward the recently reported excellent power conversion efficiencies of OPVs containing a DTDCTB donor material.

  7. P-doped organic semiconductor: Potential replacement for PEDOT:PSS in organic photodetectors

    Energy Technology Data Exchange (ETDEWEB)

    Herrbach, J.; Revaux, A., E-mail: amelie.revaux@cea.fr [University of Grenoble Alpes, CEA-LITEN, Grenoble 38000 (France); Vuillaume, D. [IEMN, CNRS, University of Lille, Villeneuve d' Ascq 59652 (France); Kahn, A. [Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

    2016-08-15

    In this work, we present an alternative to the use of PEDOT:PSS as hole transport and electron blocking layers in organic photodetectors processed by solution. As Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) is known to be sensitive to humidity, oxygen, and UV, removing this layer is essential for lifetime improvements. As a first step to achieving this goal, we need to find an alternative layer that fulfills the same role in order to obtain a working diode with similar or better performance. As a replacement, a layer of poly[(4,8-bis-(2-ethylhexyloxy)-benzo(1,2-b:4,5-b′)dithiophene)-2, 6-diyl-alt-(4-(2-ethylhexanoyl)-thieno[3,4-b]thiophene-)-2-6-diyl)] (PBDTTT-c) p-doped with the dopant tris-[1-(trifluoroethanoyl)-2-(trifluoromethyl)ethane-1,2-dithiolene] (Mo(tfd-COCF{sub 3}){sub 3}) is used. This p-doped layer effectively lowers the hole injection barrier, and the low electron affinity of the polymer prevents the injection of electrons into the active layer. We show similar device performance under light and the improvements of detection performance with the doped layer in comparison with PEDOT:PSS, leading to a detectivity of 1.9 × 10{sup 13} cm (Hz){sup 1/2} (W){sup −1}, competitive with silicon diodes used in imaging applications. Moreover, contrary to PEDOT:PSS, no localization of the p-doped layer is needed, leading to a diode active area defined by the patterned electrodes.

  8. The Development, Evaluation, and Validation of a Financial Stress Scale for Undergraduate Students

    Science.gov (United States)

    Northern, Jebediah J.; O'Brien, William H.; Goetz, Paul W.

    2010-01-01

    Financial stress is commonly experienced among college students and is associated with adverse academic, mental health, and physical health outcomes. Surprisingly, no validated measures of financial stress have been developed for undergraduate populations. The present study was conducted to generate and evaluate a measure of financial stress for…

  9. Analysis of the PEDOT:PSS/Si nanowire hybrid solar cell with a tail state model

    Science.gov (United States)

    Ho, Kuan-Ying; Li, Chi-Kang; Syu, Hong-Jhang; Lai, Yi; Lin, Ching-Fuh; Wu, Yuh-Renn

    2016-12-01

    In this paper, the electrical properties of the poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS)/silicon nanowire hybrid solar cell have been analyzed and an optimized structure is proposed. In addition, the planar PEDOT:PSS/c-Si hybrid solar cell is also modeled for comparison. We first developed a simulation software which is capable of modeling organic/inorganic hybrid solar cells by including Gaussian shape density of states into Poisson and drift-diffusion solver to present the tail states and trap states in the organic material. Therefore, the model can handle carrier transport, generation, and recombination in both organic and inorganic materials. Our results show that at the applied voltage near open-circuit voltage (Voc), the recombination rate becomes much higher at the PEDOT:PSS/Si interface region, which limits the fill factor and Voc. Hence, a modified structure with a p-type amorphous silicon (a-Si) layer attached on the interface of Si layer and an n+-type Si layer inserted near the bottom contact are proposed. The highest conversion efficiency of 16.10% can be achieved if both structures are applied.

  10. Theoretical considerations regarding the existence of PsO and PsS+

    International Nuclear Information System (INIS)

    Farazdel, A.; Cade, P.E.

    1977-01-01

    It has been proposed from experimental studies and in analogy with hydrogen compounds that PsO may be an entity of some importance, or an intermediate, in the reaction of positronium, Ps, with aqueous oxyacid species such as H 2 PO 4 - , HSO 4 - , ClO 4 - , and NO 3 - . This communication explores the stability of PsO and PsS, or [O - :e + ] and [S - :e + ], respectively, relative to dissociation into Ps and O( 3 P) or S( 3 P) on the basis of restricted Hartree-Fock calculations for the PsO and PsS systems and certain correlation correction arguments. A reasonable lower estimate of the dissociation energy to Y+Ps of >-0.47 eV for PsO and >0.70 eV for PsS is obtained. It is suggested that a modest correlation correction to the positron affinity (PA) of O - would very probably lead to a bound state system for PsO. (Auth.)

  11. Results of RNV studies and /sup 201/Tl myocardial scintigraphy in patients with progressive systemic scleroderma (PSS)

    Energy Technology Data Exchange (ETDEWEB)

    Ammari, B.; Hotze, A.; Gruenwald, F.; Biersack, H.J.; Biltz, H.; Kuester, W.

    1988-12-01

    Prognosis of progressive systemic scleroderma (PSS) depends directly on the extent of visceral organ involvement, and in particular, on the cardiac, renal and pulmonary appearance. Therapeutic approaches therefore require periodic followup with non-invasive methods to evaluate the actual course of disease and the success of therapy. Tl-201 scintigraphy showed pathologic heart abnormalities in 47% and RNV in 23% of the PSS patients. Our results and published data reveal the sensitivity of both myocardial scans and RNV in the evaluation of patients with PSS. Other current methods for the diagnosis of heart diseases, however, such as echocardiography should also be performed. In patients with PSS coronary angiography, however, usually shows normal coronary vessels.

  12. Assessing emotional status following acquired brain injury: the clinical potential of the depression, anxiety and stress scales.

    Science.gov (United States)

    Ownsworth, Tamara; Little, Trudi; Turner, Ben; Hawkes, Anna; Shum, David

    2008-10-01

    To investigate the clinical potential of the Depression, Anxiety and Stress Scales (DASS 42) and its shorter version (DASS 21) for assessing emotional status following acquired brain injury. Participants included 23 individuals with traumatic brain injury (TBI), 25 individuals with brain tumour and 29 non-clinical controls. Investigations of internal consistency, test-re-test reliability, theory-consistent differences, sensitivity to change and concurrent validity were conducted. Internal consistency of the DASS was generally acceptable (r > 0.70), with the exception of the anxiety scale for the TBI sample. Test-re-test reliability (1-3 weeks) was sound for the depression scale (r > 0.75) and significant but comparatively lower for other scales (r = 0.60-0.73, p scale (p DASS in the context of hospital discharge was demonstrated for depression and stress (p 0.05). Concurrent validity with the Hospital Anxiety and Depression Scale was significant for all scales of the DASS (p DASS following ABI, further research examining the factor structure of existing and modified versions of the DASS is recommended.

  13. Stress

    Science.gov (United States)

    ... taking care of an aging parent. With mental stress, the body pumps out hormones to no avail. Neither fighting ... with type 1 diabetes. This difference makes sense. Stress blocks the body from releasing insulin in people with type 2 ...

  14. Yoga reduces perceived stress and exhaustion levels in healthy elderly individuals.

    Science.gov (United States)

    Lindahl, Eric; Tilton, Katherine; Eickholt, Nicole; Ferguson-Stegall, Lisa

    2016-08-01

    This study investigated whether a 7-week yoga intervention could improve physical function, perceived stress, and mental/emotional wellness in elderly participants. 8 participants (66.5 ± 0.3 years) attended 2 60-min Hatha yoga sessions/week for 7 weeks, and performed pre- and post-intervention assessments. Balance was assessed using a 5-test battery. Flexibility was measured by sit-and-reach and shoulder flexibility tests. Functional mobility tests included 8-ft up-and-go, 5 chair stands, and 4-m walk. Participants completed SF-12, exhaustion level, and Perceived Stress Scale (PSS) questionnaires. SF-12 Mental Component Summary scores, exhaustion levels, and PSS scores improved post-intervention. No differences were found for physical function measures. Yoga participation can improve mental/emotional wellness, exhaustion levels, and stress levels in elderly individuals, even without measurable improvements in physical function. Clinicians and health practitioners who work with the elderly should consider yoga as a potential therapeutic modality for improving important aspects of quality of life in this population. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Association of CD4+ T cell subpopulations and psychological stress measures in women living with HIV.

    Science.gov (United States)

    Rehm, Kristina E; Konkle-Parker, Deborah

    2017-09-01

    Psychological stress is a known immunomodulator. In individuals with HIV, depression, the most common manifestation of increased psychological stress, can affect immune function with lower CD4+ T cell counts correlating with higher levels of depression. It is unknown how other forms of psychological stress can impact immune markers in people living with HIV. We conducted a cross-sectional study to determine how CD4+ T cell subpopulations correlated with different forms of psychological stress. We recruited 50 HIV-positive women as part of the Women's Interagency HIV Study. We assessed perceived stress, worry, acute anxiety, trait anxiety, and depression through self-report questionnaires and CD4+ T cell subpopulations using flow cytometry. Our sample was 96% African-American with a mean ± SD age and body mass index of 42 ± 8.8 years and 36.6 ± 11.5 kg/m 2 , respectively. The mean ± SD scores on the psychological measures were as follows: Perceived Stress Scale (PSS), 16.5 ± 6.4; Penn State Worry Questionnaire (PSWQ), 47.7 ± 13.8; State-Trait Anxiety Inventory - State (STAIS), 39.1 ± 12.3; State-Trait Anxiety Inventory - Trait (STAIT), 40.2 ± 11.4; Center for Epidemiological Studies Depression Scale (CES-D), 15.6 ± 11.4. The mean + SD values for the immune parameters were as follows: regulatory T cells (Treg), 1.25% ± 0.7; T helper 1 (Th1), 14.9% ± 6.1; T helper 2 (Th2), 3.8% ± 2; Th1/Th2 ratio, 4.6 ± 3; and CD4+ T cell count (cells/mm 3 ), 493 ± 251. Treg levels positively correlated with PSS, STAIS, and STAIT. CD4+ T cell count negatively correlated with PSS, PSWQ, STAIS, STAIT, and CES-D. These data suggest that immune function may be impacted by various forms of psychological stress in HIV-positive women. Interventions that target stress reduction may be useful in improving immune parameters and quality of life.

  16. Effect of Pedot-Pss on Electrical and Photovoltaic Properties of ITO/MEH-PPV:PCBM/Al Organic Diodes

    International Nuclear Information System (INIS)

    Gunduz, B.

    2008-01-01

    The photovoltaic and electrical properties of ITO/MEH-PPV:PCBM/Al and ITO/PEDOT-PSS/MEHPPV:PCBM/Al organic diodes have been investigated. The ideality factor, series resistance and shunt resistance values of ITO/MEH-PPV:PCBM/Al and ITO/PEDOT-PSS/MEHPPV:PCBM/Al diodes were found to be 4.6, 6.84x10 6 Ω, 2.2x10 8 Ω and 4.02, 5.8x10 5 Ω, 2x10 7 Ω respectively. The electronic parameters of the ITO/MEH-PPV:PCBM/Al diode were improved using PEDOT-PSS conducting polymer. ITO/MEH-PPV:PCBM/Al and ITO/PEDOT-PSS/MEHPPV:PCBM/Al organic diodes indicate a photovoltaic behaviour with a maximum open circuit voltage V o c and short-circuit current I s c. The photoconductivity sensitivity and responsivity properties of the organic diodes have been characterized by transient-current measurements. The obtained electrical and photovoltaic results indicate that ITO/MEH-PPV:PCBM/Al and ITO/PEDOT-PSS/MEHPPV:PCBM/Al structures are the organic photodiodes with calculated electronic parameters and the electrical properties of the ITO/MEH-PPV:PCBM/Al diode have been improved with PEDOT-PSS conducting polymer

  17. Damping Torsional Torques in Turbine-Generator Shaft by Novel PSS Based on Genetic Algorithm and Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Abbas Shoulaie

    2010-07-01

    Full Text Available Torsional torques on turbine-generator shaft which are yields of disturbances in power systems, can reduce the useful lifetime of shaft. In this paper, these oscillations will be damped and controlled by novel Power System Stabilizers (PSSs. Complex PSS which is used in this paper will act on the excitation system in generator set and also on the controller of in High Voltage Direct Current (HVDC system. This PSS uses three terms (generator angle deviation, frequency oscillation and capacitor voltage deviation in HVDC system of the study system which includes two ties AC and DC. This is the reason that this PSS is named novel one against the conventional PSSs. In order to adjust the PSS parameters to damp the oscillations, genetic algorithm is used. To improve the application of this PSS, fuzzy logic control methods are also used which has notable effect on controlling the oscillations in study system. The simulation results show the effectiveness of designed PSS in controlling the torsional torques in turbine-generator shaft.

  18. Prenatal stress perception and coping strategies: Insights from a longitudinal prospective pregnancy cohort.

    Science.gov (United States)

    Goletzke, J; Kocalevent, R-D; Hansen, G; Rose, M; Becher, H; Hecher, K; Arck, P C; Diemert, A

    2017-11-01

    Prenatal distress has been linked to pregnancy complications and poor offspring's health, despite the fact that longitudinal assessments of various stress dimensions are still lacking. Hence, we aimed to assess perceived stress over the course of pregnancy. Moreover, we examined whether social support and coping styles are linked to prenatal stress trajectories. Data from 543 women participating in the PRINCE (Prenatal Identification of Children Health) study, a prospective population-based cohort study, was used for the present analyses. Once per trimester the women completed questionnaires regarding different psychometric measures, including the Perceived Stress Scale (PSS). Linear mixed regression models were used to examine perceived stress development longitudinally and to relate social support and coping styles to stress trajectories during pregnancy. A significant decrease of perceived stress was observed over the course of pregnancy. Stratifying the study sample according to parity, women delivering their first child had continuously lower perceived stress scores compared to women having already one or more children, and a significant decrease during pregnancy was exclusively observed in primiparous women. Both, positive coping strategies and higher perceived and received social support were independently associated with lower perceived stress, while evasive coping strategies were associated with higher levels of perceived stress. Our study reveals stress perception trajectories during pregnancies in primi- and multiparous women. Our findings underscore the need for intervention strategies aiming to improve social support and positive coping strategies especially in multiparous women in order to reduce the risks for adverse pregnancy outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Correlation between stresses and adhesion of oxide scales on Si and Ti containing NiCrAlY alloys

    International Nuclear Information System (INIS)

    Vosberg, V.; Quadakkers, W.J.; Schubert, F.; Nickel, H.

    1998-09-01

    The relation between mechanical stresses and the adhesion of alumina scales on Si- and Ti-containing NiCrAlY alloys has been investigated. Therefore the Si and Ti contents in model alloys with the base composition Ni-20Cr-10Al-Y, which were cast to achieve high purity, were varied from 0 to 2 m/0 . These solid samples were subjected to cyclic oxidation in the temperature range from 950 to 1100 C. Growth and spallation of the oxide scale were observed by gravimetry. The stresses, present at ambient temperature, were periodically determined by X-ray stress evaluation. Using these results a reasoning of the mechanisms for stress relief and damage of the scale was carried out. The addition of Silicon as well as of titanium has an evident influence on phase composition of Ni-20Cr-10Al-Y type alloys. Due to the variation of phase stability regions the thermal expansion is affected by these additions in the range from 950 to 1100 C. The expansion is enlarged by the addition of Si and lowered with increasing Ti content. (orig.)

  20. Perceived psychosocial stress and gestational weight gain among women with gestational diabetes.

    Directory of Open Access Journals (Sweden)

    Ai Kubo

    Full Text Available Growing evidence links perceived stress-a potentially modifiable psychosocial risk factor-with health behaviors and obesity. Yet little is known about the relationship between stress during pregnancy and gestational weight gain, particularly among women with pregnancy complications. We conducted a cross-sectional analysis to examine associations between psychosocial stress during pregnancy and gestational weight gain among women with gestational diabetes. We used baseline data from the Gestational Diabetes's Effects on Moms (GEM study: 1,353 women with gestational diabetes who delivered a term singleton within Kaiser Permanente Northern California were included. Perceived stress near the time of gestational diabetes diagnosis was measured using the validated Perceived Stress Scale (PSS10. Gestational weight gain was categorized according to the 2009 Institute of Medicine recommendations. Binomial regression analyses adjusted for gestational age and maternal age at the time of gestational diabetes diagnosis, and race/ethnicity and estimated rate ratios (RR and their 95% confidence interval (CI. Among women with a normal pregravid Body Mass Index (BMI 18.5-24.9 kg/m2, there was a significant association between high (Q4 PSS score and risk of both exceeding and gaining below the Institute of Medicine recommendations compared to those with lower stress (Q1 [adjusted RR = 2.16 95% CI 1.45-3.21; RR = 1.39 95% CI 1.01-1.91, respectively.] Among women with pregravid overweight/obesity (BMI≥25 kg/m2, there was no association. Although the temporal relationship could not be established from this study, there may be a complex interplay between psychosocial stress and gestational weight gain among women with gestational diabetes. Further studies examining stress earlier in pregnancy, risk of developing gestational diabetes and excess/inadequate gestational weight gain are warranted to clarify these complex relationships.

  1. Predictors of parenting stress among Malaysian mothers of children with Down syndrome.

    Science.gov (United States)

    Norizan, A; Shamsuddin, K

    2010-11-01

    Having children with intellectual disability can be stressful for most parents. Currently there are very few studies focusing on parenting stress among mothers of children with Down syndrome (DS) in Asia. The present study examined the level of parenting stress experienced by Malaysian mothers of children with DS and evaluated the child and maternal factors that contributed to parenting stress based on Hill's ABC-X Model (Hill 1949). We conducted a cross-sectional study of mothers of children with DS between the ages of 2-12 years during February-June 2008 in Kedah, a state in Peninsular Malaysia. We used self-administered questionnaires to gather data on parenting stress, child's birth history and current behavioural problems, as well as the maternal sociodemographic characteristics, coping styles and psychological well-being. Parental Stress Scale (PSS) was used to assess parenting stress. Measures of child's behavioural problem using Pediatric Symptom Checklist, mother's coping style using Carver et al. (1989) COPE inventory and their psychological well-being using Lovibond and Lovibond (1995) DASS21, a scale assessing depression, anxiety and stress were also carried out. The 147 mothers who participated in the study had an average age of 43.1 years (SD = 7.6 years), of whom 94.6% were married, 57.1% had secondary level education and 28.6% were working outside their home. Based on PSS, mean parenting stress was 37.6 (SD = 8.1). Parenting stress was significantly higher among mothers who reported having children with behavioural problems. However, parenting stress was modified by positive coping styles and negative maternal psychological well-being. The final model based on hierarchical regression analysis identified maternal depression and lack of acceptance as significant predictors of parenting stress rather than child's behavioural problems. Mean parenting stress among mothers of children with DS significantly differed by behavioural problems in their

  2. Morphology Dependent Flow Stress in Nickel-Based Superalloys in the Multi-Scale Crystal Plasticity Framework

    Directory of Open Access Journals (Sweden)

    Shahriyar Keshavarz

    2017-11-01

    Full Text Available This paper develops a framework to obtain the flow stress of nickel-based superalloys as a function of γ-γ’ morphology. The yield strength is a major factor in the design of these alloys. This work provides additional effects of γ’ morphology in the design scope that has been adopted for the model developed by authors. In general, the two-phase γ-γ’ morphology in nickel-based superalloys can be divided into three variables including γ’ shape, γ’ volume fraction and γ’ size in the sub-grain microstructure. In order to obtain the flow stress, non-Schmid crystal plasticity constitutive models at two length scales are employed and bridged through a homogenized multi-scale framework. The multi-scale framework includes two sub-grain and homogenized grain scales. For the sub-grain scale, a size-dependent, dislocation-density-based finite element model (FEM of the representative volume element (RVE with explicit depiction of the γ-γ’ morphology is developed as a building block for the homogenization. For the next scale, an activation-energy-based crystal plasticity model is developed for the homogenized single crystal of Ni-based superalloys. The constitutive models address the thermo-mechanical behavior of nickel-based superalloys for a large temperature range and include orientation dependencies and tension-compression asymmetry. This homogenized model is used to obtain the morphology dependence on the flow stress in nickel-based superalloys and can significantly expedite crystal plasticity FE simulations in polycrystalline microstructures, as well as higher scale FE models in order to cast and design superalloys.

  3. Assessment of the Depression, Anxiety, and Stress Scale (DASS-21) in untreated obstructive sleep apnea (OSA).

    Science.gov (United States)

    Nanthakumar, Shenooka; Bucks, Romola S; Skinner, Timothy C; Starkstein, Sergio; Hillman, David; James, Alan; Hunter, Michael

    2017-10-01

    The assessment of depression in obstructive sleep apnea (OSA) is confounded by symptom overlap. The Depression, Anxiety, and Stress Scale-short form (DASS-21) is a commonly used measure of negative affect, but it not known whether the DASS-21 is suitable for use in an OSA sample. This study compared the fit of Lovibond and Lovibond's (1995) correlated 3-factor structure of the DASS-21 and measurement invariance between a non-OSA and an OSA sample using confirmatory factor analysis. As measurement invariance was not found, to determine the source of non-invariance differential item functioning (DIF) was examined using dMACS. The correlated 3-factor structure (with correlated errors) of the DASS-21 was a better fit in the non-OSA sample. dMACS indicated that there was a degree of DIF for each of the subscales, especially for the Anxiety subscale, in which 2 symptoms (that are also physiological symptoms of OSA) produced lower severity scores in the OSA sample compared with the non-OSA sample. However, the degree of DIF for each of the subscales is not sufficient to cause concern when using the DASS-21; therefore, the total DASS-21 is suitable for use in an OSA sample. Interestingly, the impact of symptom overlap in anxiety symptoms may be reducing anxiety scores because of DIF, which contrasts with the proposed effect of symptom overlap in depression, where it leads to the inflation of depression scores in OSA. This deserves greater consideration in relation to OSA and other clinical disorders or chronic illness conditions with different patterns of overlapping symptoms. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  4. Emotional intelligence, perceived stress and academic performance of Sri Lankan medical undergraduates

    Directory of Open Access Journals (Sweden)

    P. Ranasinghe

    2017-02-01

    Full Text Available Abstract Background Previous research has shown that higher Emotional Intelligence (EI is associated with better academic and work performance. The present study intended to explore the relationship between EI, perceived stress and academic performance and associated factors among medical undergraduates. Methods This descriptive cross-sectional research study was conducted among 471 medical undergraduates of 2nd, 4th and final years of University of Colombo, Sri Lanka. Students were rated on self administered Perceived Stress Scale (PSS and Schutte Self-Report Emotional Intelligence Test (SEIT. Examination results were used as the dichotomous outcome variable in a logistic regression analysis. Results Females had higher mean EI scores (p = 0.014. A positive correlation was found between the EI score and the number of extracurricular activities (r = 0.121, p = 0.008. Those who were satisfied regarding their choice to study medicine, and who were planning to do postgraduate studies had significantly higher EI scores and lower PSS scores (p <0.001. Among final year undergraduates, those who passed the Clinical Sciences examination in the first attempt had a higher EI score (p <0.001 and a lower PSS score (p <0.05. Results of the binary logistic-regression analysis in the entire study population indicated that female gender (OR:1.98 and being satisfied regarding their choice of the medical undergraduate programme (OR:3.69 were significantly associated with passing the examinations. However, PSS Score and engagement in extracurricular activities were not associated with ‘Examination Results’. Conclusions Higher EI was associated with better academic performance amongst final year medical students. In addition a higher EI was observed in those who had a higher level of self satisfaction. Self-perceived stress was lower in those with a higher EI. Enhancing EI might help to improve academic performance among final year medical

  5. Scales

    Science.gov (United States)

    Scales are a visible peeling or flaking of outer skin layers. These layers are called the stratum ... Scales may be caused by dry skin, certain inflammatory skin conditions, or infections. Examples of disorders that ...

  6. Stress and coping strategies among nursing students: an international study.

    Science.gov (United States)

    Labrague, Leodoro J; McEnroe-Petitte, Denise M; Papathanasiou, Ioanna V; Edet, Olaide B; Tsaras, Konstantinos; Leocadio, Michael C; Colet, Paolo; Kleisiaris, Christos F; Fradelos, Evangelos C; Rosales, Rheajane A; Vera Santos-Lucas, Katherine; Velacaria, Pearl Irish T

    2017-12-20

    Mounting literature on stress and coping in nursing students are available; however, most of the findings are confined to a single cultural group. This study was conducted to determine the level of stress, its sources and coping strategies among nursing students from three countries: Greece, the Philippines and Nigeria. Using a descriptive, comparative research design, 547 nursing students (161 Greek nursing students, 153 Filipino nursing students, 233 Nigerian nursing students) participated in the study from August 2015 to April 2016. Two standardized instruments were used, the Perceived Stress Scale (PSS) and the Coping Behavior Inventory (CBI). Findings revealed that the degree of stress and the type of stressors and coping styles utilized by nursing students differ according to the country of origin. The year of study predicted overall stress (β = -0.149, p stress and lessen its impact such as stress management counseling, counseling programs, establishing peer and family support systems, and formulating hospital policies that will support nursing students.

  7. Stress Related Overeating Among College Students: Development of a Mood Eating Scale.

    Science.gov (United States)

    Jackson, Linda J.; Hawkins, Raymond C.

    The hypothesis that negative emotional life states accompanying life stresses are associated with overeating and weight gain cannot be adequately tested solely by laboratory analogue studies. Naturalistic, short-term longitudinal designs are needed in which individuals susceptible to mood eating can be identified prior to a stressful event and…

  8. Perceived stress and quality of life in dementia patients and their caregiving spouses: does dyadic coping matter?

    Science.gov (United States)

    Häusler, Andreas; Sánchez, Alba; Gellert, Paul; Deeken, Friederike; Rapp, Michael A; Nordheim, Johanna

    2016-11-01

    Given the well-established association between perceived stress and quality of life (QoL) in dementia patients and their partners, our goal was to identify whether relationship quality and dyadic coping would operate as mediators between perceived stress and QoL. 82 dyads of dementia patients and their spousal caregivers were included in a cross-sectional assessment from a prospective study. QoL was assessed with the Quality of Life in Alzheimer's Disease scale (QoL-AD) for dementia patients and the WHO Quality of Life-BREF for spousal caregivers. Perceived stress was measured with the Perceived Stress Scale (PSS-14). Both partners were assessed with the Dyadic Coping Inventory (DCI). Analyses of correlation as well as regression models including mediator analyses were performed. We found negative correlations between stress and QoL in both partners (QoL-AD: r = -0.62; p stress and QoL in spousal caregivers (z = 0.28; p = 0.02), but not in dementia patients. Likewise, relationship quality significantly mediated the relationship between stress and QoL in caregivers only (z = -2.41; p = 0.02). This study identified dyadic coping as a mediator on the relationship between stress and QoL in (caregiving) partners of dementia patients. In patients, however, we found a direct negative effect of stress on QoL. The findings suggest the importance of stress reducing and dyadic interventions for dementia patients and their partners, respectively.

  9. Comparison of Reliability and Validity of the Breast Cancer depression anxiety stress scales (DASS- 21) with the Beck Depression Inventory-(BDI-II) and Hospital Anxiety and Depression Scale (HADS)

    OpenAIRE

    Bener A; Alsulaiman R; Doodson LG; El Ayoubi HR

    2016-01-01

    Background: No study has been conducted to determine the reliability and validity of the Depression, Anxiety and Stress Scale (DASS-21), Hospital Anxiety and Depression [HADS] and Beck Depression Inventory (BDI-II) among the Arab Breast Cancer population. Aim: The aim of this study was to compare the reliability and validity of the Depression, Anxiety, and Stress scale (DASS-21), the Beck Depression Inventory-(BDI-II) and Hospital Anxiety and Depression Scale (HADS) among Breast Cancer women ...

  10. Posttraumatic stress disorder in new mothers: results from a two-stage U.S. national survey.

    Science.gov (United States)

    Beck, Cheryl Tatano; Gable, Robert K; Sakala, Carol; Declercq, Eugene R

    2011-09-01

    Prevalence rates of women in community samples who screened positive for meeting the DSM-IV criteria for posttraumatic stress disorder after childbirth range from 1.7 to 9 percent. A positive screen indicates a high likelihood of this postpartum anxiety disorder. The objective of this analysis was to examine the results that focus on the posttraumatic stress disorder data obtained from a two-stage United States national survey conducted by Childbirth Connection: Listening to Mothers II (LTM II) and Listening to Mothers II Postpartum Survey (LTM II/PP). In the LTM II study, 1,373 women completed the survey online, and 200 mothers were interviewed by telephone. The same mothers were recontacted and asked to complete a second questionnaire 6 months later and of those, 859 women completed the online survey and 44 a telephone interview. Data obtained from three instruments are reported in this article: Posttraumatic Stress Disorder Symptom Scale-Self Report (PSS-SR), Postpartum Depression Screening Scale (PDSS), and the Patient Health Questionnaire-2 (PHQ-2). Nine percent of the sample screened positive for meeting the diagnostic criteria of posttraumatic stress disorder after childbirth as determined by responses on the PSS-SR. A total of 18 percent of women scored above the cutoff score on the PSS-SR, which indicated that they were experiencing elevated levels of posttraumatic stress symptoms. The following variables were significantly related to elevated posttraumatic stress symptoms levels: low partner support, elevated postpartum depressive symptoms, more physical problems since birth, and less health-promoting behaviors. In addition, eight variables significantly differentiated women who had elevated posttraumatic stress symptom levels from those who did not: no private health insurance, unplanned pregnancy, pressure to have an induction and epidural analgesia, planned cesarean birth, not breastfeeding as long as wanted, not exclusively breastfeeding at 1 month

  11. Do levels of perceived stress increase with increasing age after age 65? A population-based study.

    Science.gov (United States)

    Osmanovic-Thunström, Almira; Mossello, Enrico; Åkerstedt, Torbjörn; Fratiglioni, Laura; Wang, Hui-Xin

    2015-09-01

    psychological and health-related stressors often occur in advanced ages, but little is known about perceived stress in adults aged 65 and over. This study aimed to test the hypothesis that levels of perceived stress increase with increasing age and to detect factors that may account for the association. a dementia-free cohort of 1,656 adults aged 66-97 years living at home or in institutions, participating in the Swedish National Aging and Care study, Kungsholmen (SNAC-K) was assessed for levels of perceived stress using the 10-item perceived stress scale (PSS). prevalence of high stress according to the top tertile of the population (PSS score 20+) was 7.8% in adults aged 81+ years, 7.5% in adults aged 72-78 and 6.2% in adults aged 66 years (P = 0.020). More women than men reported high stress, 8.3 versus 5.4% (P = 0.001). Levels of stress increased with increasing age (P = 0.001) in the linear regression model. This association remained after adjustment for demographic and psychosocial factors, but no longer was present after adjusting for health-related factors. health-related stress is highly prevalent in older adults and seems to play an important role in the association between levels of perceived stress and age in older adults. © The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. PSS431

    Data.gov (United States)

    Department of Veterans Affairs — Returns a list of Unit Dose medications from data in the UNIT DOSE sub-file (#55.06) of the PHARMACY PATIENT file (#55) and dispensed drugs from the DISPENSE DRUG...

  13. Climate-related environmental stress in intertidal grazers: scaling-up biochemical responses to assemblage-level processes

    Directory of Open Access Journals (Sweden)

    Elena Maggi

    2016-10-01

    Full Text Available Background Organisms are facing increasing levels of environmental stress under climate change that may severely affect the functioning of biological systems at different levels of organization. Growing evidence suggests that reduction in body size is a universal response of organisms to global warming. However, a clear understanding of whether extreme climate events will impose selection directly on phenotypic plastic responses and how these responses affect ecological interactions has remained elusive. Methods We experimentally investigated the effects of extreme desiccation events on antioxidant defense mechanisms of a rocky intertidal gastropod (Patella ulyssiponensis, and evaluated how these effects scaled-up at the population and assemblage levels. Results With increasing levels of desiccation stress, limpets showed significant lower levels of total glutathione, tended to grow less and had reduced per capita interaction strength on their resources. Discussion Results suggested that phenotypic plasticity (i.e., reduction in adults’ body size allowed buffering biochemical responses to stress to scale-up at the assemblage level. Unveiling the linkages among different levels of biological organization is key to develop indicators that can anticipate large-scale ecological impacts of climate change.

  14. Psychological assessment of ICU survivors: a comparison between the Hospital Anxiety and Depression scale and the Depression, Anxiety and Stress scale.

    Science.gov (United States)

    Sukantarat, K T; Williamson, R C N; Brett, S J

    2007-03-01

    Recovery from a critical illness can be delayed by persistent anxiety and depression. To identify such patients, a new self-report questionnaire (the Depression, Anxiety and Stress scale, DASS) was used alongside an established instrument (the Hospital Anxiety and Depression scale, HADS) in those who had spent a minimum of 3 days (median 9 days) in a general intensive care unit. Fifty-one patients were studied 3 months later, and 45 survivors were reviewed at 9 months. High Cronbach alpha values (0.92-0.95) for each subscale of DASS confirmed its internal consistency, and likewise for HADS (0.82-0.86). HADS and DASS correlated strongly at each time point both for anxiety (r = 0.88) and depression (r = 0.93), with few discrepant values on a Bland and Altman plot. DASS performs as consistently as HADS in screening for anxiety and depression, and its psychometric properties support its use in an intensive care setting.

  15. Layered sulfur/PEDOT:PSS nano composite electrodes for lithium sulfur cell applications

    Science.gov (United States)

    Anilkumar, K. M.; Jinisha, B.; Manoj, M.; Pradeep, V. S.; Jayalekshmi, S.

    2018-06-01

    Lithium-Sulfur (Li-S) cells are emerging as the next generation energy storage devices owing to their impressive electrochemical properties with high theoretical specific capacity of 1675 mAh/g. Lack of electronic conductivity of sulfur, its volume expansion during high lithium intake and the shuttling effect due to the formation of soluble polysulfides are the main limitations, delaying the commercialization of this technology. To address these challenges, in the present work, the conducting polymer PEDOT:PSS is used as the covering matrix over the sulfur particles to improve their Li storage properties. The sulfur/PEDOT:PSS nanocomposite is synthesised using the hydrothermal process and its formation with the polymer coating over sulfur nanoparticles is established from the XRD, Raman spectroscopy, FE-SEM and TEM studies. The electrochemical studies show that the cells assembled using the sulfur/PEDOT:PSS nanocomposite as the cathode, with the components taken in the weight ratio of 9:1, offer a reversible capacity of 1191 mAh g-1 at 0.1C rate. These cells display stable electrochemical capacities over 200 cycles at gradually increasing current rates. The polymer layer facilitates electronic conduction and suppresses the polysulfide formation and the volume expansion of sulfur. A reversible capacity of 664 mAh g-1 is observed after 200 cycles at 1C rate with the capacity retention of 75 % of the initial stable capacity. The highlight of the present work is the possibility to achieve high discharge capacities at high C rates and the retention of a good percentage of the initial capacity over 200 cycles, for these Li-S cells.

  16. Comparing LCC with LCA to assess PSS sustainability: the case of the eco-box

    DEFF Research Database (Denmark)

    Chong, K.N.; Dreijer, L.S.; Howard, Thomas J.

    2014-01-01

    Product/Service-Systems strategies are increasingly proving to be a source of competitive advantage and environmental improvement for engineering companies, the main hypothesis being that PSS should allow to decouple functionality, user satisfaction and financial income on the one hand, from the ...... the total environmental impact of the function-delivering technology on the other. This paper describes an integration of Life Cycle Assessment (LCA) and Life Cycle Costing (LCC), in an attempt to see if the two life cycle elements are related....

  17. Capacitated vehicle routing problem for PSS uses based on ubiquitous computing: An emerging markets approach

    OpenAIRE

    Alberto Ochoa-Ortíz; Francisco Ornelas-Zapata; Lourdes Margain-Fuentes; Miguel Gastón Cedillo-Campos; Jöns Sánchez-Aguilar; Rubén Jaramillo-Vacio; Isabel Ávila

    2015-01-01

    El problema de ruteo de vehículos bajo las limitaciones de capacidad y basado en computación ubicua desde una perspectiva relacionada con PSS (Producto-Servicio de Sistemas) para desarrollar configuraciones para el transporte urbano de mercancías es abordado. Éste trabajo considera las especificidades de la logística urbana bajo un contexto de mercados emergentes. En este caso, involucra: i) bajas competencias logísticas de los tomadores de decisiones; ii) la limitada disponibilidad de datos;...

  18. Highly porous scaffolds of PEDOT:PSS for bone tissue engineering.

    Science.gov (United States)

    Guex, Anne Géraldine; Puetzer, Jennifer L; Armgarth, Astrid; Littmann, Elena; Stavrinidou, Eleni; Giannelis, Emmanuel P; Malliaras, George G; Stevens, Molly M

    2017-10-15

    Conjugated polymers have been increasingly considered for the design of conductive materials in the field of regenerative medicine. However, optimal scaffold properties addressing the complexity of the desired tissue still need to be developed. The focus of this study lies in the development and evaluation of a conductive scaffold for bone tissue engineering. In this study PEDOT:PSS scaffolds were designed and evaluated in vitro using MC3T3-E1 osteogenic precursor cells, and the cells were assessed for distinct differentiation stages and the expression of an osteogenic phenotype. Ice-templated PEDOT:PSS scaffolds presented high pore interconnectivity with a median pore diameter of 53.6±5.9µm and a total pore surface area of 7.72±1.7m 2 ·g -1 . The electrical conductivity, based on I-V curves, was measured to be 140µS·cm -1 with a reduced, but stable conductivity of 6.1µS·cm -1 after 28days in cell culture media. MC3T3-E1 gene expression levels of ALPL, COL1A1 and RUNX2 were significantly enhanced after 4weeks, in line with increased extracellular matrix mineralisation, and osteocalcin deposition. These results demonstrate that a porous material, based purely on PEDOT:PSS, is suitable as a scaffold for bone tissue engineering and thus represents a promising candidate for regenerative medicine. Tissue engineering approaches have been increasingly considered for the repair of non-union fractions, craniofacial reconstruction or large bone defect replacements. The design of complex biomaterials and successful engineering of 3-dimensional tissue constructs is of paramount importance to meet this clinical need. Conductive scaffolds, based on conjugated polymers, present interesting candidates to address the piezoelectric properties of bone tissue and to induce enhanced osteogenesis upon implantation. However, conductive scaffolds have not been investigated in vitro in great measure. To this end, we have developed a highly porous, electrically conductive scaffold

  19. Photovoltaic performance of hybrid ITO/PEDOT:PSS/n-SnS/Al solar cell structure

    Science.gov (United States)

    Jain, Priyal; Arun, P.

    2016-07-01

    The present paper discusses the performance of ITO/PEDOT:PSS/n-SnS/Al structured solar cells fabricated by thermal evaporation. The performance characterizing parameters such as the open circuit voltage, short circuit current density, series resistance, parallel resistance, ideality factor and the overall efficiency were found to be dependent on the SnS grain size in the nano-meter regime and incident light intensity. The experimental work directly reconfirms the theoretical results and ideas raised in the literature by early researchers.

  20. Electrical characterization of the ITO/NiPc/PEDOT : PSS junction diode

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Mutabar; Sayyad, M H; Karimov, Kh S; Wahab, Fazal, E-mail: mutabar_shah@hotmail.co, E-mail: mutabarshah@gmail.co [Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Topi, District Swabi, Khyber Pakhtunkhwa 23640 (Pakistan)

    2010-10-13

    This paper reports on the fabrication and characterization of an ITO/NiPc/PEDOT : PSS junction diode. A thin film of nickel phthalocyanine (NiPc) was deposited by the thermal vacuum deposition method on indium tin oxide (ITO) used as a substrate. The current-voltage characteristics of the diode were measured at room temperature under dark condition and showed rectifying behaviour. The values of several electrical parameters such as ideality factor, barrier height, conductivity, and series and shunt resistances were calculated.

  1. The Effectiveness of Parent-Child Play Therapy on Decreasing Depression Symptoms in Children with Cancer, Decreasing Perceived Stress on Their Mothers and Improving Parent-Child Relationship

    Directory of Open Access Journals (Sweden)

    رویا سادات علویان

    2017-01-01

    Full Text Available Present study, aimed to assess the effect of parent-child play therapy on decreasing depression symptoms in children with cancer, decreasing perceived stress of their mothers and improving the parent-child relationship. A total of 14 children diagnosed with cancer were selected, among the patients of Dr. Sheikh Hospital in the city of Mashhad, and randomly assigned into two groups of intervention and control. Mothers completed the Perceived Stress Scale (PSS and the Parent-Child Relationship Scale (PCRS, the children completed the Child Depression Inventory (CDI, both in pre-test and post-test. Eight sessions of parent-child play therapy were adminstered separately for every pair of mother-child from intervention group. Data were analyzed by using analysis of covariance. Compared to the control group, CDI scores of intervention group reduced significantly from pre to post test. Also scores of PCRS increased significantly for the intervention group. PSS Scores of intervention groups was not significantly different from control group. As a result, parent-child play therapy can be effective in reducing depression symptoms of children with cancer, and improving the parent-child relationship; while, it was not effective for reducing mothers' level of perceived stress.

  2. Posttraumatic stress symptomatology as a mediator of the relationship between warzone exposure and physical health symptoms in men and women.

    Science.gov (United States)

    Wachen, Jennifer Schuster; Shipherd, Jillian C; Suvak, Michael; Vogt, Dawne; King, Lynda A; King, Daniel W

    2013-06-01

    The mediating role of posttraumatic stress symptomatology (PSS) on the association between warzone exposure and physical health symptoms in 7 bodily systems (cardiovascular, dermatological, gastrointestinal, genitourinary, musculoskeletal, neurological, and pulmonary) was examined. We also examined if mediation effects varied as a function of sex. A sample of 317 U.S. Gulf war veterans was assessed for warzone exposure, PSS, and physical health symptoms 10 years after deployment. PSS was significantly associated with postdeployment physical health in all symptom categories when accounting for predeployment health (with effect sizes ranging from a 1.27-1.64 increase in the likelihood of postdeployment physical health symptoms with a 1 standard deviation increase in the PSS symptoms). PSS severity mediated the relationship between warzone exposure and postdeployment symptoms in all physical health domains (with percent mediation ranging 44%-75%). A significant Warzone Exposure × PSS interaction emerged for 5 outcomes such that the effect of PSS on physical health was stronger for veterans reporting lower warzone exposure. No significant interactions with sex emerged. These findings suggest the important influence of PSS on physical health symptoms for both men and women. Published 2013. This article is a US Government work and is in the public domain in the USA.

  3. A mixed multiscale model better accounting for the cross term of the subgrid-scale stress and for backscatter

    Science.gov (United States)

    Thiry, Olivier; Winckelmans, Grégoire

    2016-02-01

    In the large-eddy simulation (LES) of turbulent flows, models are used to account for the subgrid-scale (SGS) stress. We here consider LES with "truncation filtering only" (i.e., that due to the LES grid), thus without regular explicit filtering added. The SGS stress tensor is then composed of two terms: the cross term that accounts for interactions between resolved scales and unresolved scales, and the Reynolds term that accounts for interactions between unresolved scales. Both terms provide forward- (dissipation) and backward (production, also called backscatter) energy transfer. Purely dissipative, eddy-viscosity type, SGS models are widely used: Smagorinsky-type models, or more advanced multiscale-type models. Dynamic versions have also been developed, where the model coefficient is determined using a dynamic procedure. Being dissipative by nature, those models do not provide backscatter. Even when using the dynamic version with local averaging, one typically uses clipping to forbid negative values of the model coefficient and hence ensure the stability of the simulation; hence removing the backscatter produced by the dynamic procedure. More advanced SGS model are thus desirable, and that better conform to the physics of the true SGS stress, while remaining stable. We here investigate, in decaying homogeneous isotropic turbulence, and using a de-aliased pseudo-spectral method, the behavior of the cross term and of the Reynolds term: in terms of dissipation spectra, and in terms of probability density function (pdf) of dissipation in physical space: positive and negative (backscatter). We then develop a new mixed model that better accounts for the physics of the SGS stress and for the backscatter. It has a cross term part which is built using a scale-similarity argument, further combined with a correction for Galilean invariance using a pseudo-Leonard term: this is the term that also does backscatter. It also has an eddy-viscosity multiscale model part that

  4. Effects of pentacene-doped PEDOT:PSS as a hole-conducting layer on the performance characteristics of polymer photovoltaic cells

    OpenAIRE

    Kim, Hyunsoo; Lee, Jungrae; Ok, Sunseong; Choe, Youngson

    2012-01-01

    We have investigated the effect of pentacene-doped poly(3,4-ethylenedioxythiophene:poly(4-styrenesulfonate) [PEDOT:PSS] films as a hole-conducting layer on the performance of polymer photovoltaic cells. By increasing the amount of pentacene and the annealing temperature of pentacene-doped PEDOT:PSS layer, the changes of performance characteristics were evaluated. Pentacene-doped PEDOT:PSS thin films were prepared by dissolving pentacene in 1-methyl-2-pyrrolidinone solvent and mixing with PEDO...

  5. Recognizing Academic Performance, Sleep Quality, Stress Level, and Mental Health using Personality Traits, Wearable Sensors and Mobile Phones.

    Science.gov (United States)

    Sano, Akane; Phillips, Andrew J; Yu, Amy Z; McHill, Andrew W; Taylor, Sara; Jaques, Natasha; Czeisler, Charles A; Klerman, Elizabeth B; Picard, Rosalind W

    2015-06-01

    What can wearable sensors and usage of smart phones tell us about academic performance, self-reported sleep quality, stress and mental health condition? To answer this question, we collected extensive subjective and objective data using mobile phones, surveys, and wearable sensors worn day and night from 66 participants, for 30 days each, totaling 1,980 days of data. We analyzed daily and monthly behavioral and physiological patterns and identified factors that affect academic performance (GPA), Pittsburg Sleep Quality Index (PSQI) score, perceived stress scale (PSS), and mental health composite score (MCS) from SF-12, using these month-long data. We also examined how accurately the collected data classified the participants into groups of high/low GPA, good/poor sleep quality, high/low self-reported stress, high/low MCS using feature selection and machine learning techniques. We found associations among PSQI, PSS, MCS, and GPA and personality types. Classification accuracies using the objective data from wearable sensors and mobile phones ranged from 67-92%.

  6. Development of a coping with stress scale for a non-western population of children and adolescents.

    Science.gov (United States)

    Gökler DanIşman, Ilgın; Yıldız, Nejla; Yiğit, İbrahim

    2017-11-01

    In the related literature numerous instruments have been developed to measure children and adolescents' coping with stress. Considering the cultural differences in individuals' choice for coping strategies, along with the limitations of the existing measures of coping for children and adolescents (e.g., being derived from coping measures developed for adults; unrepresentative samples with limited age range, etc.), the current study aimed to construct a self-report coping scale for a non-western population of children and adolescents. The study design included both qualitative and quantitative methodology. Three consecutive studies were conducted for the development and validation of the Children and Adolescents' Coping with Stress Scale (CACSS), a self-report measure assessing coping strategies of children and adolescents aged from 9 to 18 in response to self-identified stressors. Exploratory and confirmatory factor analyses resulted in a 61-item CACSS with 10 factors. The scale appears to have a clear factor structure; sufficient temporal stability; and good convergent, discriminant, and construct validity. By addressing limitations of existing coping scales, CACSS is believed to contribute to the literature as a developmentally appropriate and multidimensional tool.

  7. Extending the utility of the Depression Anxiety Stress scale by examining its psychometric properties in Chinese settings.

    Science.gov (United States)

    Chan, Raymond C K; Xu, Ting; Huang, Jia; Wang, Yi; Zhao, Qing; Shum, David H K; O'Gorman, John; Potangaroa, Regan

    2012-12-30

    The Depression Anxiety Stress scale (DASS) is a widely used instrument for assessing mental health status, but the construct validity of the Chinese version of the test has not been demonstrated. The current study recruited three independent samples of Chinese participants to examine its reliability, factor structure, and utility in differentiating groups expected to show high and low scores on the scales. The first sample comprised 605 undergraduate student volunteers from Beijing, the second sample comprised 138 residents from the Sichuan Province who had experienced the 2008 earthquake there, and the third sample comprised 86 Beijing residents. Cronbach's alpha values in excess of 0.80 were found for all samples and all scales. Confirmatory factor analysis with the student sample supported a three-factor latent structure for the DASS (depression, anxiety, and stress). Substantially higher scores on all scales were found for the Sichuan earthquake sample compared with the Beijing resident's sample. Implications of these findings for the assessment of mental status using the DASS in China are discussed. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  8. A paper-based electrode using a graphene dot/PEDOT:PSS composite for flexible solar cells

    KAUST Repository

    Lee, Chuan-Pei

    2017-04-22

    We have synthesized a metal-free composite ink that contains graphene dots (GDs) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) that can be used on paper to serve as the counter electrode in a flexible dye-sensitized solar cell (DSSC). This paper-based GD/PEDOT:PSS electrode is low-cost, light-weight, flexible, environmentally friendly, and easy to cut and process for device fabrication. We determined the GD/PEDOT:PSS composite effectively fills the dense micro-pores in the paper substrate, which leads to improved carrier transport in the electrode and a 3-fold enhanced cell efficiency as compared to the paper electrode made with sputtered Pt. Moreover, the DSSC with the paper electrode featuring the GD/PEDOT:PSS composite did not fail in photovoltaic tests even after bending the electrode 150 times, whereas the device made with the Pt-based paper electrode decreased in efficiency by 45% after such manipulation. These exceptional properties make the metal-free GD/PEDOT:PSS composite ink a promising electrode material for a wide variety of flexible electronic applications.

  9. Silicon surface passivation by PEDOT: PSS functionalized by SnO2 and TiO2 nanoparticles.

    Science.gov (United States)

    García-Tecedor, M; Karazhanov, S Zh; Vásquez, G C; Haug, H; Maestre, D; Cremades, A; Taeño, M; Ramírez-Castellanos, J; González-Calbet, J M; Piqueras, J; You, C C; Marstein, E S

    2018-01-19

    In this paper, we present a study of silicon surface passivation based on the use of spin-coated hybrid composite layers. We investigate both undoped poly(3,4-ethylenedioxythiophene)/poly-(styrenesulfonate) (PEDOT:PSS), as well as PEDOT:PSS functionalized with semiconducting oxide nanomaterials (TiO 2 and SnO 2 ). The hybrid compound was deposited at room temperature by spin coating-a potentially lower cost, lower processing time and higher throughput alternative compared with the commonly used vacuum-based techniques. Photoluminescence imaging was used to characterize the electronic properties of the Si/PEDOT:PSS interface. Good surface passivation was achieved by PEDOT:PSS functionalized by semiconducting oxides. We show that control of the concentration of semiconducting oxide nanoparticles in the polymer is crucial in determining the passivation performance. A charge carrier lifetime of about 275 μs has been achieved when using SnO 2 nanoparticles at a concentration of 0.5 wt.% as a filler in the composite film. X-ray diffraction (XRD), scanning electron microscopy, high resolution transmission electron microscopy (HRTEM), energy dispersive x-ray in an SEM, and μ-Raman spectroscopy have been used for the morphological, chemical and structural characterization. Finally, a simple model of a photovoltaic device based on PEDOT:PSS functionalized with semiconducting oxide nanoparticles has been fabricated and electrically characterized.

  10. In Situ Complementary Doping, Thermoelectric Improvements, and Strain-Induced Structure within Alternating PEDOT:PSS/PANI Layers.

    Science.gov (United States)

    Andrei, Virgil; Bethke, Kevin; Madzharova, Fani; Bronneberg, Aafke Cecile; Kneipp, Janina; Rademann, Klaus

    2017-09-27

    Although the deposition of alternating layers from poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and polyaniline (PANI) salts has recently provided a breakthrough in the field of conductive polymers, the cause for the conductivity improvement has remained unclear. In this work, we report a cooperative doping effect between alternating PANI base and PEDOT:PSS layers, resulting in electrical conductivities of 50-100 S cm -1 and power factors of up to 3.0 ± 0.5 μW m -1 K -2 , which surpass some of the recent values obtained for protonated PANI/PEDOT:PSS multilayers by a factor of 20. In this case, the simultaneous improvement in the electrical conductivity of both types of layers is caused by the in situ protonation of PANI, which corresponds to the removal of the excess acidic PSS chains from the PEDOT:PSS grains. The interplay between the functional groups' reactivity and the supramolecular chain reorganization leads to an array of preparation-dependent phenomena, including a stepwise increase in the film thickness, an alternation in the electrical conductivity, and the formation of a diverse surface landscape. The latter effect can be traced to a buildup of strain within the layers, which results in either the formation of folds or the shrinkage of the film. These results open new paths for designing nanostructured thin-film thermoelectrics.

  11. High Performance of PEDOT:PSS/n-Si Solar Cells Based on Textured Surface with AgNWs Electrodes

    Science.gov (United States)

    Jiang, Xiangyu; Zhang, Pengbo; Zhang, Juan; Wang, Jilei; Li, Gaofei; Fang, Xiaohong; Yang, Liyou; Chen, Xiaoyuan

    2018-02-01

    Hybrid heterojunction solar cells (HHSCs) have gained extensive research and attention due to simple device structure and low-cost technological processes. Here, HHSCs are presented based on a highly transparent conductive polymer poly(3,4ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) directly spin-coated on an n-type crystalline silicon with microscale surface textures, which are prepared by traditional chemical etching. We have studied interface properties between PEDOT:PSS and textured n-Si by varying coating conditions. Final power conversion efficiency (PCE) could arrive at 8.54% by these simple solution-based fabrication processes. The high conversion efficiency is attributed to the fully conformal contact between PEDOT:PSS film and textured silicon. Furthermore, the reflectance of the PEDOT:PSS layer on textured surface is analyzed by changing film thickness. In order to improve the performance of the device, silver nanowires were employed as electrodes because of its better optical transmittance and electrical conductivity. The highest PCE of 11.07% was achieved which displayed a 29.6% enhancement compared with traditional silver electrodes. These findings imply that the combination of PEDOT:PSS film and silver nanowire transparent electrodes pave a promising way for realizing high-efficiency and low-cost solar cells.

  12. Surface analysis of the selective excimer laser patterning of a thin PEDOT:PSS film on flexible polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Schaubroeck, David, E-mail: David.Schaubroeck@elis.ugent.be [Center for Microsystems Technology (CMST), imec and Ghent University, Technologiepark 15, B-9052 Ghent (Belgium); De Smet, Jelle; Willems, Wouter [Center for Microsystems Technology (CMST), imec and Ghent University, Technologiepark 15, B-9052 Ghent (Belgium); Cools, Pieter; De Geyter, Nathalie; Morent, Rino [Research Unit Plasma Technology (RUPT), Department of Applied Physics, Faculty of Engineering, Ghent University, Sint-Pietersnieuwstraat 41, B-9000 Ghent (Belgium); De Smet, Herbert; Van Steenbeerge, Geert [Center for Microsystems Technology (CMST), imec and Ghent University, Technologiepark 15, B-9052 Ghent (Belgium)

    2016-07-15

    Highlights: • Laser patterning of thin film PEDOT:PSS on polymer foils is characterized in great detail. • PEDOT:PSS does not need to be fully removed to create electrically insulating patterns. • The underlying polymer foil influences the ablation behavior. - Abstract: Fast patterning of highly conductive polymers like PEDOT:PSS (poly (3,4-ethylene dioxythiophene): polystyrene sulfonate) with lasers can contribute to the development of industrial production of liquid crystal displays on polymer foils. In this article, the selective UV laser patterning of a PEDOT:PSS film on flexible polymer films is investigated. Based on their optical properties, three polymer films are investigated: polyethylene terephthalate (PET), polymethyl methacrylate (PMMA) and cellulose triacetate (TAC). Ablation parameters for a 110 nm PEDOT:PSS film on these polymer films are optimized. A detailed study of the crater depth, topography and surface composition are provided using optical profilometry, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The electrical insulation of the lines is measured and correlated to the crater analyses for different laser settings. Finally, potential ablation parameters for each of the polymer films are derived.

  13. Enhanced photoelectrochemical performance of inorganic–organic hybrid consisting of BiVO{sub 4} and PEDOT:PSS

    Energy Technology Data Exchange (ETDEWEB)

    Trzciński, K. [Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk (Poland); Szkoda, M., E-mail: mariusz-szkoda@wp.pl [Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk (Poland); Siuzdak, K.; Sawczak, M. [Centre for Plasma and Laser Engineering, The Szewalski Institute of Fluid Flow Machinery, Fiszera 14, 80-231 Gdańsk (Poland); Lisowska-Oleksiak, A., E-mail: alo@pg.gda.pl [Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk (Poland)

    2016-12-01

    Highlights: • Bismuth vanadate layers were prepared using pulsed laser deposition technique. • The modification method of BiVO{sub 4} by PEDOT:PSS was developed. • Modified layers exhibited higher photoactivity than bare BiVO{sub 4}. • Prepared material can act as semiconducting layer in photoelectrochemical cells. - Abstract: The PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)) was electrodeposited on a thin layer of bismuth vanadate (BiVO{sub 4}) prepared using the pulsed laser deposition technique onto FTO. The inorganic–organic junction was characterized by Raman spectroscopy, UV–vis spectroscopy and scanning electron microscopy. Chronoamperometry curves, recorded under simulated solar light illumination, were performed to determine generated photocurrent during water and hydroquinone oxidation at the electrode surface. Experiments were performed for three types of electrode materials: (i) FTO/BiVO{sub 4}, (ii) FTO/PEDOT:PSS and (iii) FTO/BiVO{sub 4}/PEDOT:PSS in aqueous electrolyte. Almost 5 times higher photocurrent in electrolyte containing hole scavenger was generated after modification of BiVO{sub 4} photoanode with electrodeposited polymer. It is noteworthy that anodic photocurrent was stable even after 4 h of illumination. Cyclic voltammetry curves of FTO/BiVO{sub 4}/PEDOT:PSS recorded before and after experiments performed under electrode illumination indicated that the organic part in tested junction is photo-corrosion resistant.

  14. Screening of current post-traumatic stress disorder in patients with substance use disorder using the Depression, Anxiety and Stress Scale (DASS-21): a reliable and convenient measure.

    Science.gov (United States)

    Kok, Tim; de Haan, Hein A; van der Meer, Margreet; Najavits, Lisa M; De Jong, Cor A J

    2015-01-01

    Several instruments have been developed and validated as screens for post-traumatic stress disorder (PTSD) in substance use disorder (SUD) patients. Unfortunately, many of these instruments have one or several disadvantages (e.g. low specificity, low sensitivity or high costs). No research has been conducted on instruments that screen simultaneously for other psychiatric disorders, which would be a potentially time-saving and cost-effective approach. In the current study we tested the psychometric properties of the Depression, Anxiety and Stress Scale (DASS) as a screen for PTSD. The DASS was assessed in an inpatient facility during intake with 58 patients and again 4 weeks after admission. Another 138 patients were assessed 4 weeks after admission only. The results were compared to the Clinician-Administered PTSD Scale (CAPS) that was also administered after 4 weeks of abstinence. ROC curve analyses showed an area under the curve of 0.84 for the DASS at intake and 0.78 for the DASS after 4 weeks' abstinence. The DASS is therefore a reliable and convenient measure to use as a screen for PTSD in SUD patients. © 2014 S. Karger AG, Basel.

  15. Person-environment fit: using commensurate scales to predict student stress.

    Science.gov (United States)

    Puccio, G J; Talbot, R J; Joniak, A J

    1993-11-01

    The relationship between person-environment fit and stress was examined for two samples of university students (N = 55 and 79). The Kirton Adaption-Innovation Inventory (KAI) was modified to assess the students' perceptions of the adaptor-innovator style required by their course, the styles they exhibited in the course, and their ideal style preferences. To ascertain fit, the KAI total scores and subscale scores (Originality, Efficiency, and Rule/Group Conformity) were used to classify students on three dimensions: (1) perception of what style their course required, adaptive or innovative; (2) congruence between the style the course required and the style they exhibited in the course; and (3) the magnitude of the difference, if any, between the required style and the exhibited style. Points two and three are measures of fit. The dependent variable was stress. Also the students' ideal style scores, KAI total and subscales, were substituted for the exhibited scores and the classification and analyses were repeated. Analysis of the total scores revealed that a course requiring adaptive behaviours was perceived as more stressful than a course requiring innovative behaviours. Similarly, an analysis of the Rule/Group Conformity scores revealed that the greater the conformity required the greater the stress. Also the less originality demanded in the course the greater was the perceived stress. For the KAI total scores and Rule/Group Conformity scores, the two measures of fit (incongruity and magnitude of the incongruity) were not related to stress. However, analyses of the Originality and Efficiency subscales supported the importance of the P-E fit position. For both subscales, stress was associated with the magnitude of the difference between what was required in the course and what students exhibited in the course. Educational implications derived from these findings as well as recommendations for future research are discussed.

  16. Efficient and Air-Stable Planar Perovskite Solar Cells Formed on Graphene-Oxide-Modified PEDOT:PSS Hole Transport Layer

    Science.gov (United States)

    Luo, Hui; Lin, Xuanhuai; Hou, Xian; Pan, Likun; Huang, Sumei; Chen, Xiaohong

    2017-10-01

    As a hole transport layer, PEDOT:PSS usually limits the stability and efficiency of perovskite solar cells (PSCs) due to its hygroscopic nature and inability to block electrons. Here, a graphene-oxide (GO)-modified PEDOT:PSS hole transport layer was fabricated by spin-coating a GO solution onto the PEDOT:PSS surface. PSCs fabricated on a GO-modified PEDOT:PSS layer exhibited a power conversion efficiency (PCE) of 15.34%, which is higher than 11.90% of PSCs with the PEDOT:PSS layer. Furthermore, the stability of the PSCs was significantly improved, with the PCE remaining at 83.5% of the initial PCE values after aging for 39 days in air. The hygroscopic PSS material at the PEDOT:PSS surface was partly removed during spin-coating with the GO solution, which improves the moisture resistance and decreases the contact barrier between the hole transport layer and perovskite layer. The scattered distribution of the GO at the PEDOT:PSS surface exhibits superior wettability, which helps to form a high-quality perovskite layer with better crystallinity and fewer pin holes. Furthermore, the hole extraction selectivity of the GO further inhibits the carrier recombination at the interface between the perovskite and PEDOT:PSS layers. Therefore, the cooperative interactions of these factors greatly improve the light absorption of the perovskite layer, the carrier transport and collection abilities of the PSCs, and especially the stability of the cells.

  17. Substrate treatment and drying conditions effect on the properties of roll-to-roll gravure printed PEDOT:PSS thin films

    International Nuclear Information System (INIS)

    Koidis, C.; Logothetidis, S.; Kapnopoulos, C.; Karagiannidis, P.G.; Laskarakis, A.; Hastas, N.A.

    2011-01-01

    Highlights: → Drying conditions effect on the optical, electrical and structural characteristics of R2R gravure printed PEDOT:PSS thin films → Insight on microstructural, compositional and electrical characteristics of the PEDOT:PSS films by Spectroscopic Ellipsometry combined with the AFM results → Drying temperature increase leads to less remained water volume fraction, smaller particles, lower film roughness and finally better conductivity → Transformation of spherical particles in solution to pancakes in thin films is attributed to the drying process → The increase of corona efficiency leads to a deeper PET surface modification without affecting the adhesion of PEDOT:PSS - Abstract: The optical, structural and electrical properties of poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonic acid) (PEDOT:PSS) thin films printed by roll-to-roll gravure have been investigated. Corona treatment has been applied to enhance the adhesion of PEDOT:PSS on PolyEthylene Terephthalate (PET) web. It has been found that there was a stronger in-depth surface modification of PET with the increase of corona efficiency; however, the adhesion of PEDOT:PSS was not actually affected. Also, Spectroscopic Ellipsometry and Atomic Force Microscopy have been used to extract information on the mechanisms that define PEDOT:PSS properties. The increase of the drying temperature of the PEDOT:PSS films has been found to reduce the remaining water inside the films and lead to the decrease of the PEDOT:PSS particles size.

  18. Effects of pentacene-doped PEDOT:PSS as a hole-conducting layer on the performance characteristics of polymer photovoltaic cells.

    Science.gov (United States)

    Kim, Hyunsoo; Lee, Jungrae; Ok, Sunseong; Choe, Youngson

    2012-01-05

    We have investigated the effect of pentacene-doped poly(3,4-ethylenedioxythiophene:poly(4-styrenesulfonate) [PEDOT:PSS] films as a hole-conducting layer on the performance of polymer photovoltaic cells. By increasing the amount of pentacene and the annealing temperature of pentacene-doped PEDOT:PSS layer, the changes of performance characteristics were evaluated. Pentacene-doped PEDOT:PSS thin films were prepared by dissolving pentacene in 1-methyl-2-pyrrolidinone solvent and mixing with PEDOT:PSS. As the amount of pentacene in the PEDOT:PSS solution was increased, UV-visible transmittance also increased dramatically. By increasing the amount of pentacene in PEDOT:PSS films, dramatic decreases in both the work function and surface resistance were observed. However, the work function and surface resistance began to sharply increase above the doping amount of pentacene at 7.7 and 9.9 mg, respectively. As the annealing temperature was increased, the surface roughness of pentacene-doped PEDOT:PSS films also increased, leading to the formation of PEDOT:PSS aggregates. The films of pentacene-doped PEDOT:PSS were characterized by AFM, SEM, UV-visible transmittance, surface analyzer, surface resistance, and photovoltaic response analysis.

  19. Enhancement of UV photodetector properties of ZnO nanorods/PEDOT:PSS Schottky junction by NGQD sensitization along with conductivity improvement of PEDOT:PSS by DMSO additive

    Science.gov (United States)

    Dhar, Saurab; Majumder, Tanmoy; Chakraborty, Pinak; Mondal, Suvra Prakash

    2018-04-01

    Schottky junction ultraviolet (UV) photodetector was fabricated by spin coating a hole conducting polymer, poly 3,4-ethylenedioxythiophene: polystyrene sulfonate (PEDOT:PSS) on hydrothermally grown zinc oxide (ZnO) nanorod arrays. The UV detector performance was significantly improved two step process. Firstly, ZnO nanorods were modified by sensitizing N doped grapheme quantum dots (NGQDs) for better photoresponce behavior. Afterwards, the junction properties as well as photoresponse was enhanced by modifying electrical conductivity of PEDOT:PSS layer with organic solvent (DMSO). Our NGQD decorated ZnO NRs/DMSO-PEDOT:PSS Schottky junction device demonstrated superior external quantum efficiency (EQE ˜ 90063 %) and responsivity (Rλ˜247 A/W) at 340 nm wavelength and -1V external bias. The response and recovery times of the final photodetector device was very fast compared to GQD as well as NGQD modified and pristine ZnO nanorod based detectors.

  20. Stress predictors in two Asian dental schools with an integrated curriculum and traditional curriculum.

    Science.gov (United States)

    Nguyen, T T T; Seki, N; Morio, I

    2018-05-01

    This study explored stress predictors and the role of instructional methods and institutional differences in perceived stress levels amongst students at two Asian dental schools. An anonymous questionnaire was distributed to undergraduate dental students at Tokyo Medical and Dental University (TMDU), Japan and the University of Medicine and Pharmacy (UMP), Hochiminh City, Vietnam in 2016. Data concerning the students' demographic information and grades, and responses to the Perceived Stress Scale (PSS) and Dental Environment Stress questionnaire (DES) were collected. The questionnaires were prepared in English and translated into Japanese and Vietnamese following a forward-backward translation process. Altogether 684 students answered the questionnaire with a response rate of 97% for TMDU and 89% for UMP. The mean DES score of UMP students was significantly higher than TMDU (P stress scores in several areas than UMP preclinical students. Having dentistry as their first choice of educational programme was a significant stress predictor for Japanese students whilst the clinical practicum was a significant stress predictor for Vietnamese students. Previous academic performance was not a significant stress predictor for students at either dental school. Dental students of an integrated, active-learning curriculum reported lower stress levels than students of a traditional, discipline-based curriculum. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. The Influence of Exercise Empowerment on Life Stress

    Directory of Open Access Journals (Sweden)

    Tonya M. Parker

    2017-10-01

    Full Text Available Background: Psychological stress – when an individual perceives that the environment exceeds their ability to meet the demands placed on them - is common in college students and exercise, and specifically instructional physical activity courses, is frequently cited as a one method of stress reduction. Objective: Determine any relationship between exercise empowerment and perceived life stress for those participating in instructional physical activity courses (IPAC. Methods: All undergraduate students (n = 3388 enrolled in IPAC in 15-week IPAC at a large university were surveyed on perceived life stress (PSS, empowerment in exercise (EES, and specific demographic variables. Results: 944 of 3388 enrolled students (Nov. 2015, April 2016 completed the survey. The data revealed GPA (p < 0.002, sex (p < 0.000, and EES (p < 0.001 showed differences for PSS. It was determined that EES, sex, and GPA predicted PSS differently for students according to their year in college. Conclusions: For freshman and seniors, sex and lower GPA were a stronger predictor of PSS with no mitigating effect of exercise empowerment. For sophomores and juniors the level of life stress was lower at higher levels of exercise empowerment. These findings support a complex relationship between exercise empowerment and life stress. While exercise is cited as a method for stress reduction the relationship between exercise empowerment and life stress for college-aged students is not as straightforward as it may seem.

  2. Stress

    DEFF Research Database (Denmark)

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  3. Stress !!!

    OpenAIRE

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten. Opvallend is dat mannelijke studenten uit Twente zich veel minder druk lijken te maken over hun studie. Onder vrouwen ligt de stress juist erg hoog ten opzichte van het landelijk gemiddelde.

  4. Optoelectronic Evaluation and Loss Analysis of PEDOT:PSS/Si Hybrid Heterojunction Solar Cells.

    Science.gov (United States)

    Yang, Zhenhai; Fang, Zebo; Sheng, Jiang; Ling, Zhaoheng; Liu, Zhaolang; Zhu, Juye; Gao, Pingqi; Ye, Jichun

    2017-12-01

    The organic/silicon (Si) hybrid heterojunction solar cells (HHSCs) have attracted considerable attention due to their potential advantages in high efficiency and low cost. However, as a newly arisen photovoltaic device, its current efficiency is still much worse than commercially available Si solar cells. Therefore, a comprehensive and systematical optoelectronic evaluation and loss analysis on this HHSC is therefore highly necessary to fully explore its efficiency potential. Here, a thoroughly optoelectronic simulation is provided on a typical planar polymer poly (3,4-ethylenedioxy thiophene):polystyrenesulfonate (PEDOT:PSS)/Si HHSC. The calculated spectra of reflection and external quantum efficiency (EQE) match well with the experimental results in a full-wavelength range. The losses in current density, which are contributed by both optical losses (i.e., reflection, electrode shield, and parasitic absorption) and electrical recombination (i.e., the bulk and surface recombination), are predicted via carefully addressing the electromagnetic and carrier-transport processes. In addition, the effects of Si doping concentrations and rear surface recombination velocities on the device performance are fully investigated. The results drawn in this study are beneficial to the guidance of designing high-performance PEDOT:PSS/Si HHSCs.

  5. Polymeric Flexible Immunosensor Based on Piezoresistive Micro-Cantilever with PEDOT/PSS Conductive Layer

    Directory of Open Access Journals (Sweden)

    Rui Zhao

    2018-02-01

    Full Text Available In this paper, a fully polymeric micro-cantilever with the surface passivation layer of parylene-C and the strain resistor of poly(3,4-ethylenedioxythiophene/poly (styrene sulfonate (PEDOT/PSS was proposed and demonstrated for immunoassays. By optimizing the design and fabrication of the polymeric micro-cantilever, a square resistance of 220 Ω/□ for PEDOT/PSS conductive layer have been obtained. The experimental spring constant and the deflection sensitivity were measured to be 0.017 N/m and 8.59 × 10−7 nm−1, respectively. The biological sensing performances of polymeric micro-cantilever were investigated by the immunoassay for human immunoglobulin G (IgG. The immunosensor was experimentally demonstrated to have a linear behavior for the detection of IgG within the concentrations of 10~100 ng/mL with a limit of detection (LOD of 10 ng/mL. The experimental results indicate that the proposed polymeric flexible conductive layer-based sensors are capable of detecting trace biological substances.

  6. Microtexturing of the conductive PEDOT:PSS Polymer for superhydrophobic organic electrochemical transistors

    KAUST Repository

    Gentile, Francesco

    2014-01-22

    Superhydrophobic surfaces are bioinspired, nanotechnology artifacts, which feature a reduced friction coefficient, whereby they can be used for a number of very practical applications including, on the medical side, the manipulation of biological solutions. In this work, we integrated superhydrophobic patterns with the conducting polymer PEDOT:PSS, one of the most used polymers in organic electronics because highly sensitive to ionized species in solution. In doing so, we combined geometry and materials science to obtain an advanced device where, on account of the superhydrophobicity of the system, the solutions of interest can be manipulated and, on account of the conductive PEDOT:PSS polymer, the charged molecules dispersed inside can be quantitatively measured. This original substrate preparation allowed to perform electrochemical measurements on ionized species in solution with decreasing concentration down to 10 -7 molar. Moreover, it was demonstrated the ability of the device of realizing specific, combined time and space resolved analysis of the sample. Collectively, these results demonstrate how a tight, interweaving integration of different disciplines can provide realistic tools for the detection of pathologies. The scheme here introduced offers breakthrough capabilities that are expected to radically improve both the pace and the productivity of biomedical research, creating an access revolution. 2014 Francesco Gentile et al.

  7. Electrochemical Impedance Analysis of a PEDOT:PSS-Based Textile Energy Storage Device

    Directory of Open Access Journals (Sweden)

    Ida Nuramdhani

    2017-12-01

    Full Text Available A textile-based energy storage device with electroactive PEDOT:PSS (poly(3,4-ethylenedioxythiophene/poly(4-styrenesulfonate polymer functioning as a solid-state polyelectrolyte has been developed. The device was fabricated on textile fabric with two plies of stainless-steel electroconductive yarn as the electrodes. In this study, cyclic voltammetry and electrochemical impedance analysis were used to investigate ionic and electronic activities in the bulk of PEDOT:PSS and at its interfaces with stainless steel yarn electrodes. The complex behavior of ionic and electronic origins was observed in the interfacial region between the conductive polymer and the electrodes. The migration and diffusion of the ions involved were confirmed by the presence of the Warburg element with a phase shift of 45° (n = 0.5. Two different equivalent circuit models were found by simulating the model with the experimental results: (QR(QR(QR for uncharged and (QR(QR(Q(RW for charged samples. The analyses also showed that the further the distance between electrodes, the lower the capacitance of the cell. The distribution of polymer on the cell surface also played important role to change the capacitance of the device. The results of this work may lead to a better understanding of the mechanism and how to improve the performance of the device.

  8. Tailoring the Electrochemical and Mechanical Properties of PEDOT:PSS Films for Bioelectronics

    KAUST Repository

    Elmahmoudy, Mohammed

    2017-02-21

    The effect of 3-glycidoxypropyltrimethoxysilane (GOPS) content in poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) dispersions on the properties of films spun cast from these formulations is investigated. It has been found out that the concentration of GOPS has a tremendous, yet gradual impact on the electrical, electrochemical, and mechanical properties of the PEDOT:PSS/GOPS films and that there is an optimum concentration which maximizes a particular feature of the film such as its water uptake or elasticity. The benefits of aqueous stability and mechanical strength with GOPS are to be compensated by an increase in the electrochemical impedance. GOPS aids obtaining excellent mechanical integrity in aqueous media with still highly conducting properties. Moreover, active devices like organic electrochemical transistors that contain 1 wt% GOPS, which is a concentration that leads to film with high electrical conductivity with sufficient mechanical stability and softness, exhibit steady performance over three weeks. These results suggest that variations in the concentration of such an additive like GOPS can enable a facile co-optimization of electrical and mechanical properties of a conducting polymer film for in vivo bioelectronics application.

  9. Hybrid device based on GaN nanoneedles and MEH-PPV/PEDOT:PSS polymer

    International Nuclear Information System (INIS)

    Shin, Min Jeong; Gwon, Dong-Oh; Lee, Chan-Mi; Lee, Gang Seok; Jeon, In-Jun; Ahn, Hyung Soo; Yi, Sam Nyung; Ha, Dong Han

    2015-01-01

    Highlights: • A hybrid device was demonstrated by using MEH-PPV, PEDOT:PSS, and GaN nanoneedles. • I–V curve of the hybrid device showed its rectification behaviour, similar to a diode. • EL peak originated by the different potential barriers at MEH-PPV and GaN interface. - Abstract: A hybrid device that combines the properties of organic and inorganic semiconductors was fabricated and studied. It incorporated poly[2-methoxy-5-(2-ethylhexyloxy)- 1,4-phenylenevinylene] (MEH-PPV) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as organic polymers and GaN nanoneedles as an inorganic semiconductor. Layers of the two polymers were spin coated on to the GaN nanoneedles. The one peak in the electroluminescence spectrum originated from the MEH-PPV layer owing to the different potential barriers of electrons and holes at its interface with the GaN nanoneedles. However, the photoluminescence spectrum showed peaks due to both GaN nanoneedles and MEH-PPV. Such hybrid structures, suitably developed, might be able to improve the efficiency of optoelectronic devices

  10. Hybrid device based on GaN nanoneedles and MEH-PPV/PEDOT:PSS polymer

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Min Jeong; Gwon, Dong-Oh; Lee, Chan-Mi; Lee, Gang Seok [Department of Applied Science, Korea Maritime and Ocean University, Busan 606-791 (Korea, Republic of); Jeon, In-Jun [Department of Nano-semiconductor Engineering, Korea Maritime and Ocean University, Busan 606-791 (Korea, Republic of); Ahn, Hyung Soo [Department of Applied Science, Korea Maritime and Ocean University, Busan 606-791 (Korea, Republic of); Department of Nano-semiconductor Engineering, Korea Maritime and Ocean University, Busan 606-791 (Korea, Republic of); Yi, Sam Nyung, E-mail: snyi@kmou.ac.kr [Department of Applied Science, Korea Maritime and Ocean University, Busan 606-791 (Korea, Republic of); Department of Nano-semiconductor Engineering, Korea Maritime and Ocean University, Busan 606-791 (Korea, Republic of); Ha, Dong Han [Division of Convergence Technology, Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of)

    2015-08-15

    Highlights: • A hybrid device was demonstrated by using MEH-PPV, PEDOT:PSS, and GaN nanoneedles. • I–V curve of the hybrid device showed its rectification behaviour, similar to a diode. • EL peak originated by the different potential barriers at MEH-PPV and GaN interface. - Abstract: A hybrid device that combines the properties of organic and inorganic semiconductors was fabricated and studied. It incorporated poly[2-methoxy-5-(2-ethylhexyloxy)- 1,4-phenylenevinylene] (MEH-PPV) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as organic polymers and GaN nanoneedles as an inorganic semiconductor. Layers of the two polymers were spin coated on to the GaN nanoneedles. The one peak in the electroluminescence spectrum originated from the MEH-PPV layer owing to the different potential barriers of electrons and holes at its interface with the GaN nanoneedles. However, the photoluminescence spectrum showed peaks due to both GaN nanoneedles and MEH-PPV. Such hybrid structures, suitably developed, might be able to improve the efficiency of optoelectronic devices.

  11. Planning Support Systems (PSS-Based Spatial Plan Alternatives and Environmental Assessment

    Directory of Open Access Journals (Sweden)

    Hee-Sun Choi

    2016-03-01

    Full Text Available Spatial planning is at the core of national land and urban development. Many countries and cities seek sustainable development through various means such as coordinated environmental planning, environmental assessment, and internalization of environmental analysis and planning. A Planning Support System (PSS is a GIS (Geographic Information System-based, spatial decision-making support system that incorporates a variety of theories and pertinent models. This study adopted the “What if?” model to design an alternative spatial plan that includes generation of predictive scenarios and is relatively easy to use. In the cities studied, we identified a total of six scenarios based on the main drivers of development—namely, population and spatial policies. Subsequently, we assessed the alternatives for their environmental impact, preparing sensitivity maps for each major environmental issue in the target area (natural ecosystem, air and microclimate, natural disasters. One projected advantage of the “What if?” model is that its digital visualization of proposed plans may improve public awareness and involvement. Furthermore, the tool is expected to be highly useful in ensuring the objectivity of quantitative analyses. However, it is necessary to develop a PSS that is both standardized and tailored to the particular needs of each area. Finally, the development of an e-governance system will be beneficial in ensuring public access to the decision making process.

  12. Polymeric Flexible Immunosensor Based on Piezoresistive Micro-Cantilever with PEDOT/PSS Conductive Layer.

    Science.gov (United States)

    Zhao, Rui; Sun, Ying

    2018-02-03

    In this paper, a fully polymeric micro-cantilever with the surface passivation layer of parylene-C and the strain resistor of poly(3,4-ethylenedioxythiophene)/poly (styrene sulfonate) (PEDOT/PSS) was proposed and demonstrated for immunoassays. By optimizing the design and fabrication of the polymeric micro-cantilever, a square resistance of 220 Ω/□ for PEDOT/PSS conductive layer have been obtained. The experimental spring constant and the deflection sensitivity were measured to be 0.017 N/m and 8.59 × 10 -7 nm -1 , respectively. The biological sensing performances of polymeric micro-cantilever were investigated by the immunoassay for human immunoglobulin G (IgG). The immunosensor was experimentally demonstrated to have a linear behavior for the detection of IgG within the concentrations of 10~100 ng/mL with a limit of detection (LOD) of 10 ng/mL. The experimental results indicate that the proposed polymeric flexible conductive layer-based sensors are capable of detecting trace biological substances.

  13. Influence of Egyptian electrical grid and nuclear power plants under disturbances based on PSS/E

    International Nuclear Information System (INIS)

    Shaat, M. K.; Kotb, S. A.; Mahmoud, H. M.

    2012-12-01

    The capacity of the electrical power system in Egypt will increase rapidly in the coming twenty years. In year 2018, power generation will be connecting to the Egyptian electrical grid. Consequently, the interaction of nuclear power plants and other systems become a very important issue, and a detailed nuclear power model for the medium-term and long-term power system stability should be developed. However, there is no nuclear unit model that can describe the detailed characteristics of the nuclear unit in the available commercial power system simulation software. In this paper, a detailed pressurized water reactor (PWR) nuclear unit model for medium-term and long-term power system transient stability is proposed. The model is implemented by a user defined program in PSS/E through PSS/E Mat lab Seamanlike interface. Also this paper proposes a design of power plant rector controller for the nuclear power plant. This model can be used to analyze the difference influences between the Egyptian electrical grid and nuclear power plants for examples transient fault on electrical grid and outage of nuclear power plant. The simulation results show that the proposed model is valid. (Author)

  14. LOFT facility PSS experiments: analysis of wet well vertical loads resulting from transient initiation

    International Nuclear Information System (INIS)

    Berta, V.T.

    1977-05-01

    Fourteen experiments on the Loss-of-Fluid Test (LOFT) facility pressure suppression system (PSS) are analyzed in relation to the vertical load generated on the suppression tank in the first 0.5 sec of the transient. Variations in principle parameters affecting the generation of vertical loads were included in the experiments. The internal and external vent submergences are identified from the analysis as being parameters which are first order in influencing the magnitude of the vertical load. These parameters are geometric in nature and depend only on PSS design. Physical parameters of total energy input and rate of energy input to the dry well, which influence the dry well pressurization, also are identified as being first order in influencing the magnitude of the vertical loads. The vertical load magnitude is a direct function of these geometric and physical parameters. The analysis indicates that a small value in any one of the parameters will cause the vertical load to be small and to have little dependence on the magnitude of the other parameters. In addition, the phenomena of nonuniform nonsynchronized vent inlet pressures, which have origins that are either geometric, physical, or a combination of both, act as a significant vertical load reduction mechanism

  15. Development of a Flexible Strain Sensor Based on PEDOT:PSS for Thin Film Structures

    Directory of Open Access Journals (Sweden)

    Alexandra El Zein

    2017-06-01

    Full Text Available The aim of this study was to develop and optimize a reproducible flexible sensor adapted to thin low-density polyethylene (LDPE films and/or structures to enable their deformation measurements. As these deformations are suspected to be weak (less than 10%, the developed sensor needs to be particularly sensitive. Moreover, it is of prime importance that sensor integration and usability do not modify the mechanical behavior of its LDPE substrate. The literature review allowed several materials to be investigated and an elastomer/intrinsically conductive polymer PEDOT:PSS (CleviosTM filled composite was selected to simultaneously combine mechanical properties and electrical conductivity. This composite (made of PEDOT:PSS and silicone Bluesil® presented satisfying compatibilities with piezoresistive effects, negative temperature performances (in a range from −60 °C to 20 °C, as well as elongation properties (until the elastic limit of the substrate was reached. The method used for creating the sensor is fully described, as are the optimization of the sensor manufacture in terms of used materials, the used amount of materials where the percolation theory aspects must be considered, the adhesion to the substrate, and the manufacturing protocol. Electromechanical characterization was performed to assess the gauge factor (K of the sensor on its substrate.

  16. Measuring Social Capital Investment: Scale Development and Examination of Links to Social Capital and Perceived Stress

    Science.gov (United States)

    Wegner, Rhiana; Gong, Jie; Fang, Xiaoyi; Kaljee, Linda

    2014-01-01

    Individuals with greater social capital have better health outcomes. Investment in social capital likely increases one’s own social capital, bearing great implications for disease prevention and health promotion. In this study, the authors developed and validated the Social Capital Investment Inventory (SCII). Direct effects of social capital investment on perceived stress, and indirect effects through social capital were examined. 397 Participants from Beijing and Wuhan, China completed surveys. Analyses demonstrated that the SCII has a single factor structure and strong internal consistency. Structural equation modeling showed that individuals who invested more in social capital had greater bonding social capital, and subsequently less perceived stress. Results suggest that disease prevention and health promotion programs should consider approaches to encourage social capital investment; individuals may be able to reduce stress by increasing their investment in social capital. Future research is needed to provide additional empirical support for the SCII and observed structural relationships. PMID:25648725

  17. Preparation of graphene oxide/poly (3,4-ethylenedioxytriophene): Poly (styrene sulfonate) (PEDOT:PSS) electrospun nanofibers

    International Nuclear Information System (INIS)

    Efelina, Vita; Widianto, Eri; Rusdiana, Dadi; Nugroho, A. A.; Kusumaatmaja, Ahmad; Triyana, Kuwat; Santoso, Iman

    2016-01-01

    Graphene oxide (GO)/Poly (3,4-Ethylenedioxytriophene):Poly (styrene Sulfonate) (PEDOT:PSS) nanofibers have been successfully fabricated by a simple electrospinning technique to develop conductive nanofibers with polyvinyl alcohol (PVA) act as a carrier solution. Graphene oxide has been synthesized by Hummer’s method and has been confirmed by Raman Spectroscopy, FTIR and UV-Vis Spectroscopy. GO/PEDOT:PSS composite nanofibers. The structural and morphological properties were characterized by Scanning Electron Microscopy (SEM). The result of SEM show that GO/PEDOT:PSS nanofibers has a relatively uniform morphology nanofiber with diameter between 180 nm - 340 nm with smooth nanofiber surface. The produced nanofibers from this study can be utilized for various applications such as flexible, conductive and transparent electrode.

  18. Impact of PSS and STATCOM Devices to the Dynamic Performance of a Multi-Machine Power System

    Directory of Open Access Journals (Sweden)

    G. Shahgholian

    2017-12-01

    Full Text Available This paper studies the impact of leveraging both static syn­ch­ron­ous compensator (STATCOM and power system stabilizer (PSS on multi-machine power systems. Considering a sta­ndard IEEE 9-bus test power network, classic and intelligent controllers are applied to achieve the desirable system performance. Simulated tests show the usefulness of STATCOM on network power quality in terms of voltage profile. In addition, it is shown that it can significantly improve the damping oscillations of synchronous generator under normal and abnormal network conditions. As shown, the PSS also contributes to improving the synch­ron­o­u­s generator parameters. It is also observed that using intelligent controllers with STATCOM and PSS leads to a better perfor­ma­nc­e relative to the classic controllers.

  19. Surface analysis of the selective excimer laser patterning of a thin PEDOT:PSS film on flexible polymer films

    Science.gov (United States)

    Schaubroeck, David; De Smet, Jelle; Willems, Wouter; Cools, Pieter; De Geyter, Nathalie; Morent, Rino; De Smet, Herbert; Van Steenbeerge, Geert

    2016-07-01

    Fast patterning of highly conductive polymers like PEDOT:PSS (poly (3,4-ethylene dioxythiophene): polystyrene sulfonate) with lasers can contribute to the development of industrial production of liquid crystal displays on polymer foils. In this article, the selective UV laser patterning of a PEDOT:PSS film on flexible polymer films is investigated. Based on their optical properties, three polymer films are investigated: polyethylene terephthalate (PET), polymethyl methacrylate (PMMA) and cellulose triacetate (TAC). Ablation parameters for a 110 nm PEDOT:PSS film on these polymer films are optimized. A detailed study of the crater depth, topography and surface composition are provided using optical profilometry, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The electrical insulation of the lines is measured and correlated to the crater analyses for different laser settings. Finally, potential ablation parameters for each of the polymer films are derived.

  20. Deposition of PEDOT: PSS Nanoparticles as a Conductive Microlayer Anode in OLEDs Device by Desktop Inkjet Printer

    Directory of Open Access Journals (Sweden)

    S. Ummartyotin

    2011-01-01

    Full Text Available A simple microfabrication technique for delivering macromolecules and patterning microelectrode arrays using desktop inkjet printer was described. Aqueous solution of nanoparticle of poly (3,4-ethylenedioxythiophene (PEDOT doped with polystyrene sulfonic acid (PSS was prepared while its particle size, the surface tension, and the viscosity of the solution were adjusted to be suitable for deposition on a flexible cellulose nanocomposite substrate via inkjet printer. The statistical average of PEDOT: PSS particle size of 100 nm was observed. The microthickness, surface morphology, and electrical conductivity of the printed substrate were then characterized by profilometer, atomic force microscope (AFM, and four-point probe electrical measurement, respectively. The inkjet deposition of PEDOT: PSS was successfully carried out, whilst retained its transparency feature. Highly smooth surface (roughness ~23–44 nm was achieved.

  1. Stable angular emission spectra in white organic light-emitting diodes using graphene/PEDOT:PSS composite electrode.

    Science.gov (United States)

    Cho, Hyunsu; Lee, Hyunkoo; Lee, Jonghee; Sung, Woo Jin; Kwon, Byoung-Hwa; Joo, Chul-Woong; Shin, Jin-Wook; Han, Jun-Han; Moon, Jaehyun; Lee, Jeong-Ik; Cho, Seungmin; Cho, Nam Sung

    2017-05-01

    In this work, we suggest a graphene/ poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) composite as a transparent electrode for stabilizing white emission of organic light-emitting diodes (OLEDs). Graphene/PEDOT:PSS composite electrodes have increased reflectance when compared to graphene itself, but their reflectance is still lower than that of ITO itself. Changes in the reflectance of the composite electrode have the advantage of suppressing the angular spectral distortion of white emission OLEDs and achieving an efficiency of 16.6% for white OLEDs, comparable to that achieved by graphene-only electrodes. By controlling the OLED structure to compensate for the two-beam interference effect, the CIE color coordinate change (Δxy) of OLEDs based on graphene/PEDOT:PSS composite electrodes is 0.018, less than that based on graphene-only electrode, i.e.,0.027.

  2. Preparation of graphene oxide/poly (3,4-ethylenedioxytriophene): Poly (styrene sulfonate) (PEDOT:PSS) electrospun nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Efelina, Vita; Widianto, Eri [Department of Physics, Universitas Gadjah Mada, Sekip Utara BLS.21 Yogyakarta, 55281 Indonesia (Indonesia); Rusdiana, Dadi [Department of Physical Education, Universitas Pendidikan Indonesia, Bandung (Indonesia); Nugroho, A. A. [Department of Physics, Institut Teknologi Bandung, Jl. Ganesha 10 Bandung (Indonesia); Kusumaatmaja, Ahmad; Triyana, Kuwat; Santoso, Iman, E-mail: iman.santoso@ugm.ac.id [Department of Physics, Universitas Gadjah Mada, Sekip Utara BLS.21 Yogyakarta, 55281 Indonesia (Indonesia); Nanomaterials Research Group, Universitas Gadjah Mada,, Sekip Utara, Yogyakarta (Indonesia)

    2016-04-19

    Graphene oxide (GO)/Poly (3,4-Ethylenedioxytriophene):Poly (styrene Sulfonate) (PEDOT:PSS) nanofibers have been successfully fabricated by a simple electrospinning technique to develop conductive nanofibers with polyvinyl alcohol (PVA) act as a carrier solution. Graphene oxide has been synthesized by Hummer’s method and has been confirmed by Raman Spectroscopy, FTIR and UV-Vis Spectroscopy. GO/PEDOT:PSS composite nanofibers. The structural and morphological properties were characterized by Scanning Electron Microscopy (SEM). The result of SEM show that GO/PEDOT:PSS nanofibers has a relatively uniform morphology nanofiber with diameter between 180 nm - 340 nm with smooth nanofiber surface. The produced nanofibers from this study can be utilized for various applications such as flexible, conductive and transparent electrode.

  3. Depression and anxiety in patients with rheumatoid arthritis: prevalence rates based on a comparison of the Depression, Anxiety and Stress Scale (DASS) and the hospital, Anxiety and Depression Scale (HADS)

    OpenAIRE

    Covic Tanya; Cumming Steven R; Pallant Julie F; Manolios Nick; Emery Paul; Conaghan Philip G; Tennant Alan

    2012-01-01

    Abstract Background While it is recognised that depression is prevalent in Rheumatoid Arthritis (RA), recent studies have also highlighted significant levels of anxiety in RA patients. This study compared two commonly used scales, the Depression Anxiety and Stress Scale (DASS) and the Hospital Anxiety and Depression Scale (HADS), in relation to their measurement range and cut points to consider the relative prevalence of both constructs, and if prevalence rates may be due to scale-specific ca...

  4. Do Exercisers With Musculoskeletal Injuries Report Symptoms of Depression and Stress?

    DEFF Research Database (Denmark)

    Lichtenstein, Mia Beck; Gudex, Claire; Andersen, Kjeld

    2018-01-01

    on somatic symptoms. OBJECTIVE: The primary aim of this study was to estimate the prevalence of depression and emotional stress, and measure self-rated health in regular exercisers presenting to a sports medicine clinic with musculoskeletal injury. The secondary aim was to identify psychosocial factors...... associated with depression in injured exercisers and the potential need for psychological counselling. DESIGN: A cross-sectional survey study. SETTING: A sports medicine clinic for injuries of the foot, knee, or shoulder. PARTICIPANTS: Regular exercisers with present injuries (n=694) and exercisers without...... completed the Major Depression Inventory (MDI), Perceived Stress Scale (PSS), health-related quality of life (EQ-5D-5L), and questions on sociodemographics, exercise habits, and injury history. RESULTS: Symptoms of depression were reported by 12% of injured exercisers and 5% of non-injured controls (p

  5. Reliability and validity of the Japanese version of the Resilience Scale and its short version.

    Science.gov (United States)

    Nishi, Daisuke; Uehara, Ritei; Kondo, Maki; Matsuoka, Yutaka

    2010-11-17

    The clinical relevance of resilience has received considerable attention in recent years. The aim of this study is to demonstrate the reliability and validity of the Japanese version of the Resilience Scale (RS) and short version of the RS (RS-14). The original English version of RS was translated to Japanese and the Japanese version was confirmed by back-translation. Participants were 430 nursing and university psychology students. The RS, Center for Epidemiologic Studies Depression Scale (CES-D), Rosenberg Self-Esteem Scale (RSES), Social Support Questionnaire (SSQ), Perceived Stress Scale (PSS), and Sheehan Disability Scale (SDS) were administered. Internal consistency, convergent validity and factor loadings were assessed at initial assessment. Test-retest reliability was assessed using data collected from 107 students at 3 months after baseline. Mean score on the RS was 111.19. Cronbach's alpha coefficients for the RS and RS-14 were 0.90 and 0.88, respectively. The test-retest correlation coefficients for the RS and RS-14 were 0.83 and 0.84, respectively. Both the RS and RS-14 were negatively correlated with the CES-D and SDS, and positively correlated with the RSES, SSQ and PSS (all p reliability, and relatively low concurrent validity. RS-14 was equivalent to the RS in internal consistency, test-retest reliability, and concurrent validity. Low scores on the RS, a positive correlation between the RS and perceived stress, and a relatively low correlation between the RS and depressive symptoms in this study suggest that validity of the Japanese version of the RS might be relatively low compared with the original English version.

  6. Reliability and validity of the Japanese version of the Resilience Scale and its short version

    Directory of Open Access Journals (Sweden)

    Kondo Maki

    2010-11-01

    Full Text Available Abstract Background The clinical relevance of resilience has received considerable attention in recent years. The aim of this study is to demonstrate the reliability and validity of the Japanese version of the Resilience Scale (RS and short version of the RS (RS-14. Findings The original English version of RS was translated to Japanese and the Japanese version was confirmed by back-translation. Participants were 430 nursing and university psychology students. The RS, Center for Epidemiologic Studies Depression Scale (CES-D, Rosenberg Self-Esteem Scale (RSES, Social Support Questionnaire (SSQ, Perceived Stress Scale (PSS, and Sheehan Disability Scale (SDS were administered. Internal consistency, convergent validity and factor loadings were assessed at initial assessment. Test-retest reliability was assessed using data collected from 107 students at 3 months after baseline. Mean score on the RS was 111.19. Cronbach's alpha coefficients for the RS and RS-14 were 0.90 and 0.88, respectively. The test-retest correlation coefficients for the RS and RS-14 were 0.83 and 0.84, respectively. Both the RS and RS-14 were negatively correlated with the CES-D and SDS, and positively correlated with the RSES, SSQ and PSS (all p Conclusions This study demonstrates that the Japanese version of RS has psychometric properties with high degrees of internal consistency, high test-retest reliability, and relatively low concurrent validity. RS-14 was equivalent to the RS in internal consistency, test-retest reliability, and concurrent validity. Low scores on the RS, a positive correlation between the RS and perceived stress, and a relatively low correlation between the RS and depressive symptoms in this study suggest that validity of the Japanese version of the RS might be relatively low compared with the original English version.

  7. The kinesin AtPSS1 promotes synapsis and is required for proper crossover distribution in meiosis.

    Directory of Open Access Journals (Sweden)

    Yann Duroc

    2014-10-01

    Full Text Available Meiotic crossovers (COs shape genetic diversity by mixing homologous chromosomes at each generation. CO distribution is a highly regulated process. CO assurance forces the occurrence of at least one obligatory CO per chromosome pair, CO homeostasis smoothes out the number of COs when faced with variation in precursor number and CO interference keeps multiple COs away from each other along a chromosome. In several organisms, it has been shown that cytoskeleton forces are transduced to the meiotic nucleus via KASH- and SUN-domain proteins, to promote chromosome synapsis and recombination. Here we show that the Arabidopsis kinesin AtPSS1 plays a major role in chromosome synapsis and regulation of CO distribution. In Atpss1 meiotic cells, chromosome axes and DNA double strand breaks (DSBs appear to form normally but only a variable portion of the genome synapses and is competent for CO formation. Some chromosomes fail to form the obligatory CO, while there is an increased CO density in competent regions. However, the total number of COs per cell is unaffected. We further show that the kinesin motor domain of AtPSS1 is required for its meiotic function, and that AtPSS1 interacts directly with WIP1 and WIP2, two KASH-domain proteins. Finally, meiocytes missing AtPSS1 and/or SUN proteins show similar meiotic defects suggesting that AtPSS1 and SUNs act in the same pathway. This suggests that forces produced by the AtPSS1 kinesin and transduced by WIPs/SUNs, are required to authorize complete synapsis and regulate maturation of recombination intermediates into COs. We suggest that a form of homeostasis applies, which maintains the total number of COs per cell even if only a part of the genome is competent for CO formation.

  8. Pore-Scale Investigation on Stress-Dependent Characteristics of Granular Packs and Their Impact on Multiphase Fluid Distribution

    Science.gov (United States)

    Torrealba, V.; Karpyn, Z.; Yoon, H.; Hart, D. B.; Klise, K. A.

    2013-12-01

    The pore-scale dynamics that govern multiphase flow under variable stress conditions are not well understood. This lack of fundamental understanding limits our ability to quantitatively predict multiphase flow and fluid distributions in natural geologic systems. In this research, we focus on pore-scale, single and multiphase flow properties that impact displacement mechanisms and residual trapping of non-wetting phase under varying stress conditions. X-ray micro-tomography is used to image pore structures and distribution of wetting and non-wetting fluids in water-wet synthetic granular packs, under dynamic load. Micro-tomography images are also used to determine structural features such as medial axis, surface area, and pore body and throat distribution; while the corresponding transport properties are determined from Lattice-Boltzmann simulations performed on lattice replicas of the imaged specimens. Results are used to investigate how inter-granular deformation mechanisms affect fluid displacement and residual trapping at the pore-scale. This will improve our understanding of the dynamic interaction of mechanical deformation and fluid flow during enhanced oil recovery and geologic CO2 sequestration. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  9. In-silico analysis of water and carbon relations under stress conditions. A multi-scale perspective centered on fruit

    Directory of Open Access Journals (Sweden)

    Valentina eBALDAZZI

    2013-12-01

    Full Text Available Fruit development, from its early stages, is the result of a complex network of interacting processes, at different scales. These include cell division, cell expansion but also nutrient transports from the plant and exchanges with the environment. In the presence of nutrients limitation, in particular, the plant reacts as whole, by modifying its architecture, metabolism and reproductive strategy, determining the resources available for fruits development, which in turn affects the overall source-sink balance of the system.Here we present an integrated model of tomato that explicitly accounts for early developmental changes (from cell division to harvest, and use it to investigate the impact of water deficit and carbon limitation on nutrient fluxes and fruit growth, in both dry and fresh mass. Variability in fruit response is analyzed at two different scales: among trusses, at the plant level and within the cells population, at the fruit scale. Results show that the effect of stress on individual cells strongly depends on their age, size and uptake capabilities and that the timing of stress application, together with the fruit position on the plant, is crucial to determine the final phenotypic outcome. Water deficit and carbon depletion impacted either source size, source activity or sink strength with contrasted effects on fruit growth. An important prediction of the model is the major role of symplasmic transport of carbon in early stage of fruit development, as a catalyst of cells and fruit growth.

  10. Reach-scale land use drives the stress responses of a resident stream fish.

    Science.gov (United States)

    Blevins, Zachary W; Wahl, David H; Suski, Cory D

    2014-01-01

    Abstract To date, relatively few studies have tried to determine the practicality of using physiological information to help answer complex ecological questions and assist in conservation actions aimed at improving conditions for fish populations. In this study, the physiological stress responses of fish were evaluated in-stream between agricultural and forested stream reaches to determine whether differences in these responses can be used as tools to evaluate conservation actions. Creek chub Semotilus atromaculatus sampled directly from forested and agricultural stream segments did not show differences in a suite of physiological indicators. When given a thermal challenge in the laboratory, creek chub sampled from cooler forested stream reaches had higher cortisol levels and higher metabolic stress responses to thermal challenge than creek chub collected from warmer and more thermally variable agricultural reaches within the same stream. Despite fish from agricultural and forested stream segments having different primary and secondary stress responses, fish were able to maintain homeostasis of other physiological indicators to thermal challenge. These results demonstrate that local habitat conditions within discrete stream reaches may impact the stress responses of resident fish and provide insight into changes in community structure and the ability of tolerant fish species to persist in agricultural areas.

  11. Medical Yoga for Patients with Stress-Related Symptoms and Diagnoses in Primary Health Care: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Monica Köhn

    2013-01-01

    Full Text Available An increasing number of patients are suffering from stress-related symptoms and diagnoses. The purpose of this study was to evaluate the medical yoga treatment in patients with stress-related symptoms and diagnoses in primary health care. A randomized controlled study was performed at a primary health care centre in Sweden from March to June, 2011. Patients were randomly allocated to a control group receiving standard care or a yoga group treated with medical yoga for 1 hour, once a week, over a 12-week period in addition to the standard care. A total of 37 men and women, mean age of 53±12 years were included. General stress level (measured using Perceived Stress Scale (PSS, burnout (Shirom-Melamed Burnout Questionnaire (SMBQ, anxiety and depression (Hospital Anxiety and Depression Scale (HADS, insomnia severity (Insomnia Severity Index (ISI, pain (visual analogue scale (VAS, and overall health status (Euro Quality of Life VAS (EQ-VAS were measured before and after 12 weeks. Patients assigned to the Yoga group showed significantly greater improvements on measures of general stress level (P<0.000, anxiety (P<0.019, and overall health status (P<0.018 compared to controls. Treatment with medical yoga is effective in reducing levels of stress and anxiety in patients with stress-related symptoms in primary health care.

  12. Medical yoga for patients with stress-related symptoms and diagnoses in primary health care: a randomized controlled trial.

    Science.gov (United States)

    Köhn, Monica; Persson Lundholm, Ulla; Bryngelsson, Ing-Liss; Anderzén-Carlsson, Agneta; Westerdahl, Elisabeth

    2013-01-01

    An increasing number of patients are suffering from stress-related symptoms and diagnoses. The purpose of this study was to evaluate the medical yoga treatment in patients with stress-related symptoms and diagnoses in primary health care. A randomized controlled study was performed at a primary health care centre in Sweden from March to June, 2011. Patients were randomly allocated to a control group receiving standard care or a yoga group treated with medical yoga for 1 hour, once a week, over a 12-week period in addition to the standard care. A total of 37 men and women, mean age of 53 ± 12 years were included. General stress level (measured using Perceived Stress Scale (PSS)), burnout (Shirom-Melamed Burnout Questionnaire (SMBQ)), anxiety and depression (Hospital Anxiety and Depression Scale (HADS)), insomnia severity (Insomnia Severity Index (ISI)), pain (visual analogue scale (VAS)), and overall health status (Euro Quality of Life VAS (EQ-VAS)) were measured before and after 12 weeks. Patients assigned to the Yoga group showed significantly greater improvements on measures of general stress level (P < 0.000), anxiety (P < 0.019), and overall health status (P < 0.018) compared to controls. Treatment with medical yoga is effective in reducing levels of stress and anxiety in patients with stress-related symptoms in primary health care.

  13. Relationships between occupational functioning and stress among radio journalists--Assessment by means of the Psychosocial Risk Scale.

    Science.gov (United States)

    Najder, Anna; Merecz-Kot, Dorota; Wójcik, Aleksandra

    2016-01-01

    Job characteristics and the consequences of everyday stress among radio journalists who are not exposed to traumatic events have not been studied sufficiently before. We aimed at determining the most common job characteristics and their stressfulness; relationships between stress exposure, health and occupational functioning; differences between radio journalists and other journalists, and also the psychosocial risk for health and functioning in this group. The studied group involved 208 journalists, 134 of whom worked in radio stations. The respondents filled in the Psychosocial Risks Scale (PRS) developed by the Department of Health and Work Psychology of the Nofer Institute of Occupational Medicine, Łódź, Poland. Requirement of mental effort and readiness to response quickly for most of the time as well as limited possibilities for promotion were the most frequent journalists' complaints. We confirmed that higher levels of stress resulted in worse functioning--the radio journalists who experienced lower stress assessed their health status and ability to work better, were more satisfied with particular aspects of their work, and were more involved in their work. They also presented a significantly lower turnover intention. Moreover, the radio journalists were more involved in their work than other journalists, but experienced lower satisfaction, took more sick leaves and had more days of absence. Well-known relationships between stress level, satisfaction and occupational functioning were confirmed. The most important conclusion refers to the fact that psychosocial risks and stress analysis should be based on the understanding of specificity of each occupation or even position. It is so, because the same job characteristic may pose a challenge for one person, while for another--it can result in extreme discomfort and anxiety--such an attitude broadens understanding of the phenomenon. We also confirmed that the PRS is a well-designed method, appropriate to

  14. The Critical Choice of PEDOT: PSS Additives for Long Term Stability of Roll‐to‐Roll Processed OPVs

    DEFF Research Database (Denmark)

    Roth, Bérenger; Benatto, Gisele Alves dos Reis; Corazza, Michael

    2015-01-01

    The impact of additives mixed with poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) on the stability of organic photovoltaic modules is investigated for fully ambient roll-to-roll (R2R) processed indium tin oxide free modules. Four different PEDOT:PSS inks from two different...... on organic photovoltaic stability (ISOS). For the harsh indoor test (ISOS-L-3) only a slight difference in stability is observed between the different modules. During both ISOS-L-3 and ISOS-D-3 one new failure mode is observed as a result of tiny air inclusions in the barrier foil and a R2R method...

  15. Does a modified mindfulness-based cognitive therapy (MBCT) course have the potential to reduce stress and burnout in NHS GPs? Feasibility study.

    Science.gov (United States)

    Hamilton-West, Kate; Pellatt-Higgins, Tracy; Pillai, Neil

    2018-04-19

    AimTo explore, for the first time, whether a modified mindfulness-based cognitive therapy (MBCT) course has the potential to reduce stress and burnout among National Health Service (NHS) General Practitioners. There is a crisis of low morale among NHS GPs, with most describing their workload as 'unmanageable'. MBCT has been demonstrated to improve stress and burnout in other populations, but has not yet been evaluated in a cohort of NHS GPs. NHS GPs in South East England (n=22) attended a modified version of the MBCT course approved by National Institute for Health and Care Excellence for prevention of depressive relapse. This comprised eight weekly 2-h sessions with homework (mindfulness practice) between sessions. Participants completed the Maslach Burnout Inventory (MBI) and Perceived Stress Scale (PSS) before (baseline) and then again one month (T2) and three months (T3) after attending the course. We also obtained qualitative data on participants' experiences of the course.FindingsCompliance with the intervention was very high. All GPs attended at least six sessions and all completed baseline questionnaires. At T2, data were obtained from 21 participants (95%); PSS scores were significantly lower than at baseline (P<0.001), as were MBI emotional exhaustion (P<0.001) and depersonalization scores (P=0.0421). At T3 we obtained data for 13 participants (59%); PSS scores and MBI emotional exhaustion scores were significantly lower (P<0.001; P=0.0024, respectively) and personal accomplishment scores were significantly higher (P<0.001) than at baseline. Participants reported that the course helped them to manage work pressures, feel more relaxed, enjoy their work and experience greater empathy and compassion (for self, colleagues and patients). Findings of this preliminary evaluation are promising. Further research is needed to evaluate this approach within a larger randomized-controlled trial.

  16. Using the Social, Attitudinal, Familial, and Environmental (S.A.F.E.) Acculturation Stress Scale to Assess the Adjustment Needs of Hispanic College Students.

    Science.gov (United States)

    Fuertes, Jairo N.; Westbrook, Franklin D.

    1996-01-01

    Reexamined the validity and reliability of the 24-item S.A.F.E. scale and found it to be a reliable measure of Hispanics' acculturation stress. Also studied the effect of generational status, gender, and socioeconomic status on the levels of acculturation stress experienced by this sample. (RJM)

  17. Child Behavior Checklist Juvenile Bipolar Disorder (CBCL-JBD) and CBCL Posttraumatic Stress Problems (CBCL-PTSP) Scales Are Measures of a Single Dysregulatory Syndrome

    Science.gov (United States)

    Ayer, Lynsay; Althoff, Robert; Ivanova, Masha; Rettew, David; Waxler, Ellen; Sulman, Julie; Hudziak, James

    2009-01-01

    Background: The Child Behavior Checklist Juvenile Bipolar Disorder (CBCL-JBD) profile and Posttraumatic Stress Problems (CBCL-PTSP) scale have been used to assess juvenile bipolar disorder (JBD) and posttraumatic stress disorder (PTSD), respectively. However, their validity is questionable according to previous research. Both measures are…

  18. Hair cortisol and self-reported stress in healthy, working adults.

    Science.gov (United States)

    Gidlow, Christopher J; Randall, Jason; Gillman, Jamie; Silk, Steven; Jones, Marc V

    2016-01-01

    Chronic stress can be important in the pathology of chronic disease. Hair cortisol concentrations (HCC) are proposed to reflect long term cortisol secretion from exposure to stress. To date, inconsistencies in the relationship between HCC and self-reported stress have been attributed to variation and limitations of perceived stress measurement. We report data from employees of two large public sector worksites (n=132). Socio-demographic, health, lifestyle, perceived stress scale (PSS), and work-related effort reward imbalance (ERI) were collected at baseline. Participants were asked to respond to mobile text messages every two days, asking them to report current stress levels (Ecological momentary assessment, EMA), and mean stress was determined overall, during work hours, and out of work hours. At 12 weeks, the appraisal of stressful life events scale (ALES) was completed and 3 cm scalp hair samples were taken, from which HCC was determined (to reflect cortisol secretion over the past 12 weeks). Mean response rate to EMA was 81.9 ± 14.9%. Associations between HCC and the various self-reported stress measures (adjusted for use of hair dye) were weak (allwork hours (ρ=.196, p=.013) and ALES Loss subscale (ρ=.241, p=.003), and two individual items from ERI (relating to future work situation). In regression analysis adjusting for other possible confounders, only the HCC-ALES Loss association remained significant (p=.011). Overall, our study confirms that EMA provides a useful measurement tool that can gather perceived stress measures in real-time. But, there was no relationship between self-reported stress collected in this way, and HCC. The modest association between HCC and stress appraisal does however, provide some evidence for the role of cognitive processes in chronic stress. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Scales of North Atlantic wind stress curl determined from the comprehensive ocean-atmosphere data set

    Science.gov (United States)

    Ehret, Laura L.; O'Brien, James J.

    1989-01-01

    Nineteen years of wind data over the North Atlantic are used to calculate a field of wind stress curl. An empirical orthogonal function (EOF) analysis is performed on this field, resulting in spatial patterns of wind stress curl and associated time series. A Monte Carlo technique is used to establish the statistical significance of each spatial pattern, and the associated time series are spectrally analyzed. The first four statistically significant EOF modes represent more than 50 percent of the curl variance, and the spatial patterns of curl associated with these modes exhibit the major elements of North Atlantic climatology. Most of the time series spectral variance is contained in annual and semiannual frequencies. The features observed include the individual annual variation of the subtropical high and the subpolar low, the annual oscillation of intensity between pressure centers, the influence of localized strong SST gradients and associated cyclogenesis regions, and the constant nature of the trades.

  20. Development of a micrometre-scale radiographic measuring method for residual stress analysis

    International Nuclear Information System (INIS)

    Moeller, D.

    1999-01-01

    The radiographic method described uses micrometre X-ray diffraction for high-resolution residual stress analysis in single crystals. The focus is on application of two x-ray optics (glass capillaries) for shaping a sufficiently fine and intensive primary beam. Due to application of a proper one-grain measuring and analysis method, the resolution results are applicable to the characteristic grain sizes of many materials. (orig.) [de

  1. Stress !!!

    NARCIS (Netherlands)

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten.

  2. Comparative Analysis of GF-1 and HJ-1 Data to Derive the Optimal Scale for Monitoring Heavy Metal Stress in Rice.

    Science.gov (United States)

    Wang, Dongmin; Liu, Xiangnan

    2018-03-06

    Remote sensing can actively monitor heavy metal contamination in crops, but with the increase of satellite sensors, the optimal scale for monitoring heavy metal stress in rice is still unknown. This study focused on identifying the optimal scale by comparing the ability to detect heavy metal stress in rice at various spatial scales. The 2 m, 8 m, and 16 m resolution GF-1 (China) data and the 30 m resolution HJ-1 (China) data were used to invert leaf area index (LAI). The LAI was the input parameter of the World Food Studies (WOFOST) model, and we obtained the dry weight of storage organs (WSO) and dry weight of roots (WRT) through the assimilation method; then, the mass ratio of rice storage organs and roots (SORMR) was calculated. Through the comparative analysis of SORMR at each spatial scale of data, we determined the optimal scale to monitor heavy metal stress in rice. The following conclusions were drawn: (1) SORMR could accurately and effectively monitor heavy metal stress; (2) the 8 m and 16 m images from GF-1 were suitable for monitoring heavy metal stress in rice; (3) 16 m was considered the optimal scale to assess heavy metal stress in rice.

  3. Correlation between the fine structure of spin-coated PEDOT:PSS and the photovoltaic performance of organic/crystalline-silicon heterojunction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Funda, Shuji; Ohki, Tatsuya; Liu, Qiming; Hossain, Jaker; Ishimaru, Yoshihiro; Ueno, Keiji; Shirai, Hajime [Graduate School of Science and Engineering, Saitama University, Saitama 338-8570 (Japan)

    2016-07-21

    We investigated the relationship between the fine structure of spin-coated conductive polymer poly(3,4-ethylenedioxythiphene):poly(styrene sulfonate) (PEDOT:PSS) films and the photovoltaic performance of PEDOT:PSS crystalline-Si (PEDOT:PSS/c-Si) heterojunction solar cells. Real-time spectroscopic ellipsometry revealed that there were two different time constants for the formation of the PEDOT:PSS network. Upon removal of the polar solvent, the PEDOT:PSS film became optically anisotropic, indicating a conformational change in the PEDOT and PSS chain. Polarized Fourier transform infrared attenuated total reflection absorption spectroscopy and Raman spectroscopy measurements also indicated that thermal annealing promoted an in-plane π-conjugated C{sub α} = C{sub β} configuration attributed to a thiophene ring in PEDOT and an out-of-plane configuration of -SO{sub 3} groups in the PSS chain with increasing composition ratio of oxidized (benzoid) to neutral (quinoid) PEDOT, I{sub qui}/I{sub ben}. The highest power conversion efficiency for the spin-coated PEDOT:PSS/c-Si heterojunction solar cells was 13.3% for I{sub qui}/I{sub ben} = 9–10 without employing any light harvesting methods.

  4. Highly Conductive PEDOT:PSS Films with 1,3-Dimethyl-2-Imidazolidinone as Transparent Electrodes for Organic Light-Emitting Diodes.

    Science.gov (United States)

    Kim, Jin Hee; Joo, Chul Woong; Lee, Jonghee; Seo, Yoon Kyung; Han, Joo Won; Oh, Ji Yoon; Kim, Jong Su; Yu, Seunggun; Lee, Jae Hyun; Lee, Jeong-Ik; Yun, Changhun; Choi, Bum Ho; Kim, Yong Hyun

    2016-09-01

    Highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PSS) films as transparent electrodes for organic light-emitting diodes (OLEDs) are doped with a new solvent 1,3-dimethyl-2-imidazolidinone (DMI) and are optimized using solvent post-treatment. The DMI doped PSS films show significantly enhanced conductivities up to 812.1 S cm(-1) . The sheet resistance of the PSS films doped with DMI is further reduced by various solvent post-treatment. The effect of solvent post-treatment on DMI doped PSS films is investigated and is shown to reduce insulating PSS in the conductive films. The solvent posttreated PSS films are successfully employed as transparent electrodes in white OLEDs. It is shown that the efficiency of OLEDs with the optimized DMI doped PSS films is higher than that of reference OLEDs doped with a conventional solvent (ethylene glycol). The results present that the optimized PSS films with the new solvent of DMI can be a promising transparent electrode for low-cost, efficient ITO-free white OLEDs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Management of journalists professional stress

    Directory of Open Access Journals (Sweden)

    Rvović Jelena J.

    2014-01-01

    Full Text Available This research has been conducted with the purpose of identifying the causes of stress (stressors within the journalists' work in Serbia, their intensity and frequency, as well as their negative impact on health on one hand, and on the other hand to identify what is the role of Human Resources Management within the media in overcoming journalists' stress caused by identified stressors. . The research method, a Questionnaire (N=60 was created as a combination of modified pSS (perceived Stress Scale and a Questionnaire proposed by Cousins et al. (2004 for measuring of work-related stress intensity, adapted to the specific features of this research. Results have revealed a large number of stressors that can and must be managed; therefore the specific goal of this research would include the creation of a draft template for management of journalists' professional stress. If the media in Serbia wish to be organizations that care about their journalists' health, they will have to adopt certain activities through a department of HR management to prevail over stress at work, due to permanent exposure of journalists to their great professional demands. However, human resources management in the media can not protect the health of their journalists most efficiently by one activity only, considering that a large number of stressors have been identified in the research. The proposed activities of HR management in overcoming the work-related stress represent only a macro-framework for outlining this phenomenon in Serbia, because we shall not be able to ascertain that the proposed template for journalists' professional stress management is completely efficient, before its application is proven empirically, i.e. in practice. This should not be regarded as a limitation to this research, considering that only a small number of credible studies in the world are using quantified data for verifying their conclusions. In any case the need for a study based on evidence

  6. Confirmatory factor analysis of the portuguese Depression Anxiety Stress Scales-21 Análisis factorial confirmatoria de la versión portuguesa de la Depression Anxiety Stress Scale-21 Análise fatorial confirmatória da versão portuguesa da Depression Anxiety Stress Scale-21

    Directory of Open Access Journals (Sweden)

    João Luís Alves Apóstolo

    2012-06-01

    Full Text Available To determine which of three published models best characterizes the factor structure of the Portuguese version of the Depression Anxiety Stress Scales-21 and to assess its validity and reliability. Confirmatory factor analysis of Depression Anxiety and Stress Scale-21 for 1,297 adult, primary care outpatients (66.7% female, Mage = 48.57 years comparing 3 models. The relationship between the Depression Anxiety Stress Scales-21 and the Positive and Negative Affect Schedule was analyzed. The correlated 3-factor model fit the data best. The scale demonstrated good internal consistency, with alpha scores of the subscales ranging from 0.836 to 0.897. Correlation with the Positive and Negative Affect Schedule was positive and moderate with the negative affect scale; it was negative and limited with the positive affect. These findings support the correlated 3-factor structure. The test demonstrated adequate reliability and construct validity, which supports its use for screening in primary care settings with Portuguese speakers.El objetivo de este estudio fue determinar cual de los tres modelos publicados mejor caracteriza la estructura factorial de la versión portuguesa de la Depression Anxiety Stress Scale-21 (DASS-21 y evaluar su validez y confiabilidad. Se compararon los tres modelos a través de análisis factorial confirmatoria de la DASS-21, aplicada el 1.297 pacientes adultos, del servicio de atención básica (66,7% mujeres; edad Media=48,57 años. La relación entre la DASS-21 y la Positive and Negative Affect Schedule (PANAS también fue analizada. El modelo de tres factores correlacionados se ajusta mejor a los datos. La escala presentó buena consistencia interna con valores alfa observados en las subescalas, variando de 0,836 a 0,897. La correlación con la PANAS fue positiva y comedida con la escala de afecto negativa, y negativa y limitada con la escala de afecto positivo. Esos resultados corroboran la estructura de tres factores. La

  7. Conversion of fracture toughness testing values from small scale three point bending test specimens to small scale yielding state (SSY) by elastic-plastic stress analysis

    International Nuclear Information System (INIS)

    Ikonen, K.

    1993-07-01

    The report describes the work performed for achieving readiness to calculate fracture toughness dependence on dimension effects and loading conditions in fracture test specimens and real structures. In the report two- and three-dimensional computer codes developed and calculational methods applied are described. One of the main goals is to converse fracture toughness from small scale three point bending test specimens to case of a depth crack in plane strain i.e. to small scale yielding state (SSY) by numerical elastic-plastic stress analysis. Thickness effect of a test specimens and effect of a crack depth are separately investigated. Tests of three point bending specimens with and without sidegrooves and curved crack front are numerically simulated and experimental and computed results are compared. J-integral is calculated along crack front and also from force-deflection dependence of the beam. For the analyses the computing system was thoroughly automatized. Measuring capacity of three point bending test specimens was tried to evaluate. (orig.) (7 refs., 54 figs.)

  8. PSS Support for Maritime Technology Ventures: From Exploration to Methodology and Theory

    DEFF Research Database (Denmark)

    Andersen, Jakob Axel Bejbro

    -efficient, competitive Eastern suppliers. The Danish suppliers - by some considered the world leaders in terms of technological knowledge - are faced with a difficult choice: Either try to survive by cutting costs and competing on price or attempt to leverage their unique knowledge of technology to the market and build...... new business ventures, which are not dependent on cost as a competitive factor. The recommendation of this thesis is to pursue the latter option and adopt entrepreneurial strategies as a means to future prosperity. To achieve this goal, the area of Product/Service-Systems (PSS) is introduced...... to validate an existing theory for entrepreneurship process against the data. This study fails to find proof for or against the assertions of the theory. In the last study, a grounded theory approach is used for building a conceptual framework for entrepreneurship processes. As such, the framework is entirely...

  9. Timing and Targeting of PSS Methods and Tools: An Empirical Study amongst Academic Contributors

    DEFF Research Database (Denmark)

    Nøhr Hinz, Hector; Bey, Niki; McAloone, Tim C.

    2013-01-01

    The emergence of product/service-systems has meant that development methods for such systems have emerged from academia. This paper investigates existing methods that are aimed at developing product/service-systems. Two aspects are determined for each examined method. The first aspect that has been...... surveyed is when a given method is meant to be used in the development of a product/service-system. This aspect has been determined through a qualitative assessment of each method. The second aspect surveyed is which persons in an organisation who are seen as the main drivers in the use of the methods....... To gain this insight a questionnaire for each method has been conducted with the authors of the methods as participants. The main finding indicates that current PSS methods cannot thoroughly support the development of product/ service-systems as their specificity is too low and that the methods need...

  10. Robust Coordinated Design of PSS and TCSC using PSO Technique for Power System Stability Enhancement

    Directory of Open Access Journals (Sweden)

    S. Panda

    2007-06-01

    Full Text Available Power system stability improvement by coordinated design of a Power System Stabilizer (PSS and a Thyristor Controlled Series Compensator (TCSC controller is addressed in this paper. Particle Swarm Optimization (PSO technique is employed for optimization of the parameterconstrained nonlinear optimization problem implemented in a simulation environment. The proposed controllers are tested on a weakly connected power system. The non-linear simulation results are presented for wide range of loading conditions with various fault disturbances and fault clearing sequences as well as for various small disturbances. The eigenvalue analysis and simulation results show the effectiveness and robustness of proposed controllers to improve the stability performance of power system by efficient damping of low frequency oscillations under various disturbances.

  11. The Roll of NaPSS Surfactant on the Ceria Nanoparticles Embedding in Polypyrrole Films

    Directory of Open Access Journals (Sweden)

    Simona Popescu

    2016-01-01

    Full Text Available Cerium oxide nanoparticles (CeO2 NPs in crystalline form have been synthesized by a coprecipitation method. CeO2 nanoparticles were then embedded in polypyrrole (PPy films during the electropolymerization of pyrrole (Py on titanium substrate. The influence of poly(sodium 4-styrenesulfonate (NaPSS surfactant used during polymerization on the embedding of CeO2 NPs in polypyrrole films was investigated. The new films were characterized in terms of surface analysis, wettability, electrochemical behaviour, and antibacterial effect. The surface and electrochemical characterization revealed the role of surfactant on PPy doping process cerium oxide incorporation. In the presence of surfactant, CeO2 NPs are preferentially embedded in the polymeric film while, without surfactant, the ceria nanoparticles are quasiuniformly spread as agglomerates onto polymeric films. The antibacterial effect of studied PPy films was substantially improved in the presence of cerium oxide and depends by the polymerization conditions.

  12. Stability improvement of wind turbine penetrated using power system stabilizer (PSS) on South Sulawesi transmission system

    Science.gov (United States)

    Siswanto, Agus; Gunadin, Indar Chaerah; Said, Sri Mawar; Suyuti, Ansar

    2018-03-01

    The purpose of this research is to improve the stability of interconnection of South Sulawesi system caused by penetration new wind turbine in Sidrap area on bus 2 and in Jeniponto area on bus 34. The method used in this research was via software Power System analysis Toolbox (PSAT) under MATLAB. In this research, there are two problems that are evaluated, the stability of the system before and after penetration wind turbine into the system South Sulawesi system. From the simulation result shows that penetration of wind turbine on bus 2 Sidrap, bus 37 Jeniponto give effect oscillation on the system. The oscillation was damped by installation of Power System Stabilizer (PSS) on bus 29 area Sungguminasa, that South Sulawesi system stable according to normal condition.

  13. Psychometric properties of the Turkish version of the 42 item Depression Anxiety Stress Scale (DASS-42) in a clinical sample.

    Science.gov (United States)

    Hekimoglu, Levent; Altun, Zeren Ozturk; Kaya, Emine Zeynep; Bayram, Nuran; Bilgel, Nazan

    2012-01-01

    To study the psychometric properties of the Turkish translation of the Depression Anxiety and Stress Scale (DASS-42) in a clinical group. Outpatients diagnosed with anxiety (n = 138; mean age = 44.5 years; 74.6% female) or depression (n = 112; mean age = 46.2 years; 77.7% female) from the psychiatric outpatient clinic of a public hospital were evaluated. A group of non-clinical volunteers (n = 250; mean age = 37 years; 68% female) served as a community group for comparison. The participants completed the Turkish versions of the DASS-42, the Beck Depression Inventory (BDI), and the Beck Anxiety Inventory (BAI). The structure of the DASS-42 was analyzed in the clinical sample using principal components extraction. The three-factor solution accounted for 56% of the total variance, with eigenvalues of 17.6, 3.0, and 2.6. The range of factor loadings was 0.55-0.85 for depression, 0.47-0.62 for anxiety, and 0.49-0.74 for stress. The Cronbach alpha values for the DASS depression, anxiety, and stress subscales were 0.94, 0.88, 0.94 respectively. The concurrent validity of the DASS was satisfactory. The non-clincal participants scored lower on all three subscales than the individuals in all of the clinical groups. The Turkish version of the DASS-42 appears to be an excellent instrument for measuring features of depression, hyperarousal, and tension in clinical groups.

  14. Topography on a subcellular scale modulates cellular adhesions and actin stress fiber dynamics in tumor associated fibroblasts

    Science.gov (United States)

    Azatov, Mikheil; Sun, Xiaoyu; Suberi, Alexandra; Fourkas, John T.; Upadhyaya, Arpita

    2017-12-01

    Cells can sense and adapt to mechanical properties of their environment. The local geometry of the extracellular matrix, such as its topography, has been shown to modulate cell morphology, migration, and proliferation. Here we investigate the effect of micro/nanotopography on the morphology and cytoskeletal dynamics of human pancreatic tumor-associated fibroblast cells (TAFs). We use arrays of parallel nanoridges with variable spacings on a subcellular scale to investigate the response of TAFs to the topography of their environment. We find that cell shape and stress fiber organization both align along the direction of the nanoridges. Our analysis reveals a strong bimodal relationship between the degree of alignment and the spacing of the nanoridges. Furthermore, focal adhesions align along ridges and form preferentially on top of the ridges. Tracking actin stress fiber movement reveals enhanced dynamics of stress fibers on topographically patterned surfaces. We find that components of the actin cytoskeleton move preferentially along the ridges with a significantly higher velocity along the ridges than on a flat surface. Our results suggest that a complex interplay between the actin cytoskeleton and focal adhesions coordinates the cellular response to micro/nanotopography.

  15. The Italian version of the Depression Anxiety Stress Scales-21: Factor structure and psychometric properties on community and clinical samples.

    Science.gov (United States)

    Bottesi, Gioia; Ghisi, Marta; Altoè, Gianmarco; Conforti, Erica; Melli, Gabriele; Sica, Claudio

    2015-07-01

    The Depression Anxiety Stress Scales-21 (DASS-21) is the short version of a self-report measure that was originally developed to provide maximum differentiation between depressive and anxious symptoms. Despite encouraging evidence, the factor structure and other features of the DASS-21 are yet to be firmly established. A community sample of 417 participants and two clinical groups (32 depressive patients and 25 anxious patients) completed the Italian version of the DASS-21 along with several measures of psychopathology. Confirmatory factor analyses suggested that the DASS-21 is a measure of general distress plus three additional orthogonal dimensions (anxiety, depression, and stress). The internal consistency and temporal stability of the measure were good; each DASS-21 scale correlated more strongly with a measure of a similar construct, demonstrating good convergent and divergent validity. Lastly, the DASS-21 demonstrated good criterion-oriented validity. The validity of the Italian DASS-21 and its utility, both for community and clinical individuals, are supported. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. The Depression Anxiety Stress Scales (DASS): normative data and latent structure in a large non-clinical sample.

    Science.gov (United States)

    Crawford, John R; Henry, Julie D

    2003-06-01

    To provide UK normative data for the Depression Anxiety and Stress Scale (DASS) and test its convergent, discriminant and construct validity. Cross-sectional, correlational and confirmatory factor analysis (CFA). The DASS was administered to a non-clinical sample, broadly representative of the general adult UK population (N = 1,771) in terms of demographic variables. Competing models of the latent structure of the DASS were derived from theoretical and empirical sources and evaluated using confirmatory factor analysis. Correlational analysis was used to determine the influence of demographic variables on DASS scores. The convergent and discriminant validity of the measure was examined through correlating the measure with two other measures of depression and anxiety (the HADS and the sAD), and a measure of positive and negative affectivity (the PANAS). The best fitting model (CFI =.93) of the latent structure of the DASS consisted of three correlated factors corresponding to the depression, anxiety and stress scales with correlated error permitted between items comprising the DASS subscales. Demographic variables had only very modest influences on DASS scores. The reliability of the DASS was excellent, and the measure possessed adequate convergent and discriminant validity Conclusions: The DASS is a reliable and valid measure of the constructs it was intended to assess. The utility of this measure for UK clinicians is enhanced by the provision of large sample normative data.

  17. Simulations of stress evolution and the current density scaling of electromigration-induced failure times in pure and alloyed interconnects

    Science.gov (United States)

    Park, Young-Joon; Andleigh, Vaibhav K.; Thompson, Carl V.

    1999-04-01

    An electromigration model is developed to simulate the reliability of Al and Al-Cu interconnects. A polynomial expression for the free energy of solution by Murray [Int. Met. Rev. 30, 211 (1985)] was used to calculate the chemical potential for Al and Cu while the diffusivities were defined based on a Cu-trapping model by Rosenberg [J. Vac. Sci. Technol. 9, 263 (1972)]. The effects of Cu on stress evolution and lifetime were investigated in all-bamboo and near-bamboo stud-to-stud structures. In addition, the significance of the effect of mechanical stress on the diffusivity of both Al and Cu was determined in all-bamboo and near-bamboo lines. The void nucleation and growth process was simulated in 200 μm, stud-to-stud lines. Current density scaling behavior for void-nucleation-limited failure and void-growth-limited failure modes was simulated in long, stud-to-stud lines. Current density exponents of both n=2 for void nucleation and n=1 for void growth failure modes were found in both pure Al and Al-Cu lines. Limitations of the most widely used current density scaling law (Black's equation) in the analysis of the reliability of stud-to-stud lines are discussed. By modifying the input materials properties used in this model (when they are known), this model can be adapted to predict the reliability of other interconnect materials such as pure Cu and Cu alloys.

  18. Large-Scale, Continuous-Flow Production of Stressed Biomass (Desulfovibrio vulgaris Hildenborough)

    Energy Technology Data Exchange (ETDEWEB)

    Geller, Jil T.; Borglin, Sharon E.; Fortney, Julian L.; Lam, Bonita R.; Hazen, Terry C.; Biggin, Mark D.

    2010-05-01

    The Protein Complex Analysis Project (PCAP, http://pcap.lbl.gov/), focuses on high-throughput analysis of microbial protein complexes in the anaerobic, sulfate-reducing organism, DesulfovibriovulgarisHildenborough(DvH).Interest in DvHas a model organism for bioremediation of contaminated groundwater sites arises from its ability to reduce heavy metals. D. vulgarishas been isolated from contaminated groundwater of sites in the DOE complex. To understand the effect of environmental changes on the organism, midlog-phase cultures are exposed to nitrate and salt stresses (at the minimum inhibitory concentration, which reduces growth rates by 50percent), and compared to controls of cultures at midlogand stationary phases. Large volumes of culture of consistent quality (up to 100 liters) are needed because of the relatively low cell density of DvHcultures (one order of magnitude lower than E. coli, for example) and PCAP's challenge to characterize low-abundance membrane proteins. Cultures are grown in continuous flow stirred tank reactors (CFSTRs) to produce consistent cell densities. Stressor is added to the outflow from the CFSTR, and the mixture is pumped through a plug flow reactor (PFR), to provide a stress exposure time of 2 hours. Effluent is chilled and held in large carboys until it is centrifuged. A variety of analyses -- including metabolites, total proteins, cell density and phospholipidfatty-acids -- track culture consistency within a production run, and differences due to stress exposure and growth phase for the different conditions used. With our system we are able to produce the requisite 100 L of culture for a given condition within a week.

  19. Stretchable and Hydrophobic Electrochromic Devices Using Wrinkled Graphene and PEDOT:PSS

    Directory of Open Access Journals (Sweden)

    Srinivasa Kartik Nemani

    2018-01-01

    Full Text Available We present an electrochromic device (ECD fabricated using PEDOT:PSS and graphene as active conductive electrode films and a flexible compliant polyurethane substrate with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonylimide (EMI-TSFI additive, as ionic medium. This device with a docile, elastic intermediate substrate along with a transparency controlled PEDOT:PSS film provides a wide color contrast and fast switching rate. We harness wrinkling instability of graphene to achieve a hydrophobic nature without compromising transparency of the ECD. This mechanical self-assembly approach helps in controlling the wavelength of wrinkles generated by inducing measured prestrain conditions and regulating the modulus contrast by selection of underlying materials used, hereby controlling the extent of transparency. The reduction and oxidation switching times for the device were analyzed to be 5.76 s and 5.34 s for a 90% transmittance change at an operating DC voltage of 15 ± 0.1 V. Strain dependent studies show that the performance was robust with the device retaining switching contrasts even at 15% uniaxial strain conditions. Our device also exhibits superior antiwetting properties with an average water contact angle of 110°  ± 2° at an induced radial prestrain of 30% in the graphene film. A wide range color contrast, flexibility, and antiwetting nature of the device envision its uses in smart windows, visors, and other wearable equipment where these functionalities are of outmost importance for developing new generation of smart interactive devices.

  20. Scaling up ITO-Free solar cells

    NARCIS (Netherlands)

    Galagan, Y.O.; Coenen, E.W.C.; Zimmermann, B.; Slooff, L.H.; Verhees, W.J.H.; Veenstra, S.C.; Kroon, J.M.; Jørgensen, M.; Krebs, F.C.; Andriessen, H.A.J.M.

    2014-01-01

    Indium-tin-oxide-free (ITO-free) polymer solar cells with composite electrodes containing current-collecting grids and a semitransparent poly(3,4-ethylenedioxythiophene):polystyrenesulfonate) (PEDOT:PSS) conductor are demonstrated. The up-scaling of the length of the solar cell from 1 to 6 cm and

  1. Versão resumida da "job stress scale": adaptação para o português Short version of the "job stress scale": a Portuguese-language adaptation

    Directory of Open Access Journals (Sweden)

    Márcia Guimarães de Mello Alves

    2004-04-01

    Full Text Available OBJETIVO: Descrever o processo de adaptação, para o português, da versão resumida da "job stress scale", originalmente elaborada em inglês. MÉTODOS: Foram avaliados seis aspectos de equivalência entre a escala original e a versão para o português: as equivalências conceitual, semântica, operacional, de itens, de medidas e funcional. Tomou-se por base um estudo de confiabilidade teste-reteste com 94 indivíduos selecionados. RESULTADOS: O estudo de confiabilidade teste-reteste entre 94 indivíduos permitiu estimativas de reprodutibilidade (coeficientes de correlação intraclasse para as dimensões de "demanda", "controle" e "apoio social" da escala de 0,88, 0,87 e 0,85, respectivamente. Para as mesmas dimensões, as estimativas de consistência interna (alpha de Cronbach foram, respectivamente, 0,79, 0,67 e 0,85. CONCLUSÕES: Os resultados sugerem que o processo de adaptação da escala foi bem sucedido, indicando que seu uso no contexto sociocultural da população de estudo (Estudo Pró-Saúde é apropriado.OBJECTIVE: To describe the adaptation to Portuguese of the short version of the "job stress scale", originally in English. METHODS: We evaluate six aspects of equivalence between the original scale and the Portuguese version: conceptual, semantic, operational, item, measurement, and functional equivalences. A reliability test-retest study was conducted with 94 selected subjects. RESULTS: Reproducibility (interclass correlation coefficients for the 'demand', 'control', and 'social support' dimensions of the scale was estimated at 0.88, 0.87, and 0.85, respectively. Internal consistency (Cronbach's alpha estimates for these same dimensions were 0.79, 0.67, and 0.85, respectively. CONCLUSIONS: Our results suggest that the adaptation of the scale was successful, and indicate that its use in the sociocultural context of the studied population (Pró-Saúde survey is appropriate.

  2. The impact of self-reported psychological stress levels on changes to peripheral blood immune biomarkers in recreational marathon runners during training and recovery.

    Science.gov (United States)

    Rehm, Kristina E; Elci, Okan U; Hahn, Kathryn; Marshall, Gailen D

    2013-01-01

    Marathon training is both physically and psychologically stressful, both of which can lead to altered immunity. The purpose of this study was to determine if the overall immunoregulatory changes associated with the physical stress of marathon training are affected by psychological stress. Nineteen recreational marathoners completed the Perceived Stress Scale (PSS), State-Trait Anxiety Inventory (STAI) and Penn State Worry Questionnaire (PSWQ), and had levels of T cell subpopulations and cytokine (IFNγ, IL4 and IL10) production determined 4 weeks before (baseline), 24-48 h before (prerace) and 1 week after (recovery) participation in a marathon. PSS scores decreased at the prerace visit compared to baseline and remained low at recovery. Compared to baseline, there were significant changes to numerous immune measures at the prerace visit, including decreases in Th1/Th2 ratio, Tc1/Tc2 ratio, Tr1 and Th3 cell populations as well as decreases in IFNγ/IL4 cytokine ratio and IL10 production. Most immune parameters had returned to near baseline values at the recovery visit. Higher levels of perceived stress, anxiety and worry exacerbated many of the alterations in immunity that were observed at the prerace visit. Higher levels of perceived stress and worry had significant effects on changes to Treg, IL4 production and the IFNγ/IL4 cytokine ratio. Stress had an additional impact on changes in IL10 production. High anxiety levels resulted in significant changes to Treg, Tr1 and Th3. These data suggest that recreational marathon runners with higher levels of psychological stress may be more at risk for the immune alterations that are common during periods of prolonged physical training. Copyright © 2013 S. Karger AG, Basel.

  3. Graphene oxide/PEDOT:PSS composite hole transport layer for efficient and stable planar heterojunction perovskite solar cells.

    Science.gov (United States)

    Lee, Da-Young; Na, Seok-In; Kim, Seok-Soon

    2016-01-21

    We investigated a graphene oxide (GO)/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) ( PSS) composite as a promising candidate for the practical application of a 2-D carbonaceous hole transport layer (HTL) to planar heterojunction perovskite solar cells (PeSCs) consisting of a transparent electrode/HTL/perovskite/fullerene/metal electrode. Both the insulating properties of GO and the non-uniform coating of the transparent electrode with GO cause the poor morphology of perovskite induced low power conversion efficiency (PCE) of 6.4%. On the other hand, PeSCs with a GO/PEDOT:PSS composite HTL, exhibited a higher PCE of 9.7% than that of a device fabricated with conventional PSS showing a PCE of 8.2%. The higher performance is attributed to the decreased series resistance (RS) and increased shunt resistance (RSh). The well-matched work-function between GO (4.9 eV) and PSS (5.1 eV) probably results in more efficient charge transport and an overall decrease in RS. The existence of GO with a large bandgap of ∼3.6 eV might induce the effective blocking of electrons, leading to an increase of RSh. Moreover, improvement in the long-term stability under atmospheric conditions was observed.

  4. A paper-based electrode using a graphene dot/PEDOT:PSS composite for flexible solar cells

    KAUST Repository

    Lee, Chuan-Pei; Lai, Kun-Yu; Lin, Chin-An; Li, Chun-Ting; Ho, Kuo-Chuan; Wu, Chih-I; Lau, Shu-Ping; He, Jr-Hau

    2017-01-01

    We have synthesized a metal-free composite ink that contains graphene dots (GDs) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) that can be used on paper to serve as the counter electrode in a flexible dye-sensitized solar

  5. HSA/PSS coated gold nanorods as thermo-triggered drug delivery vehicles for combined cancer photothermal therapy and chemotherapy

    Science.gov (United States)

    Tu, Ting-Yu; Yang, Shu-Jyuan; Wang, Chung-Hao; Lee, Shin-Yu; Shieh, Ming-Jium

    2018-02-01

    Drug delivery systems combined multimodal therapy strategies are very promising in cancer theranostic applications. In this work, a new drug-delivery vehicles based on human serum albumin (HSA)-coated gold nanorods (GNR/PSS/HSA NPs) was developed. The success of coating was verified by transmission electron microscopy (TEM), zeta potential and fourier transform infrared spectroscopy (FTIR). Furthermore, it is demonstrated that doxorubicin (DOX) is successfully loaded among multilayered gold nanorods by the electrostatic and hydrophobic force, and DOX@GNR/PSS/HSA NPs were highly biocompatible and stable in various physiological solutions. The NPs possess strong absorbance in nearinfrared (NIR) region, and high photothermal conversion efficiency for outstanding photothermal therapy applications. A bimodal drug release triggered by proteinase or NIR irradiation has been revealed, resulting in a significant chemotherapeutic effect in tumor sites because of the preferential drug accumulation and triggered release. Importantly, the in vitro and in vivo experiments demonstrated that DOX@GNR/PSS/HSA NPs, which combined photothermal and chemotherapy for cancer therapy, revealing a remarkably superior synergistic anticancer effect over either monotherapy. All these results suggested a considerable potential of DOX@GNR/PSS/HSA NPs nano-platform for antitumor therapy.

  6. PEDOT:PSS incorporated silver nanoparticles prepared by gamma radiation for the application in organic solar cells

    Directory of Open Access Journals (Sweden)

    Omayma A. Ghazy

    2015-04-01

    Full Text Available Poly(3,4-ethylenedioxythiophene:Polystyrene sulfonate (PEDOT:PSS is a dispersion used as a buffer layer on the ITO electrode in the organic solar cells. Silver nanoparticles (Ag NPs are incorporated to the dispersion using two different strategies. The first is by reduction of silver ions in the PEDOT:PSS dispersion. Chemical reduction of silver ions using sodium borohydried is compared with reduction using gamma radiation. The TEM and UV-visible spectra indicates that smaller Ag NPs are obtained for the chemical reduction method than those obtained from the radiochemical. The second strategy, is by preparing Ag NPs in polyvinyl pyrolidone (PVP solution using gamma irradiation then adding them to the PEDOT:PSS dispersion. Layers of the PEDOT:PSS incorporated different concentrations of Ag NPs (1, 2, 4, 6, 8, 10% are formed. The SEM and AFM studies of the layers morphology reveal that smooth morphology on the obtained for layers containing Ag NPs up to concentrations of 4%.

  7. Vacuum-assisted bilayer PEDOT:PSS/cellulose nanofiber composite film for self-standing, flexible, conductive electrodes.

    Science.gov (United States)

    Ko, Youngsang; Kim, Dabum; Kim, Ung-Jin; You, Jungmok

    2017-10-01

    Sustainable cellulose nanofiber (CNF)-based composites as functional conductive materials have garnered considerable attention recently for their use in soft electronic devices. In this work, self-standing, highly flexible, and conductive PEDOT:PSS-CNF composite films were developed using a simple vacuum-assisted filtration method. Two different composite films were successfully fabricated and then tested: 1) a single-layer composite composed of a mixture of PEDOT:PSS and CNF phases and 2) a bilayer composite composed of an upper PEDOT:PSS membrane layer and a CNF matrix sub-layer. The latter composite was constructed by electrostatic/hydrogen bonding interactions between PEDOT:PSS and CNFs coupled with sequential vacuum-assisted filtration. Our results demonstrated that the resultant bilayer composite film exhibited a competitive electrical conductivity (ca. 22.6Scm -1 ) compared to those of previously reported cellulose-based composites. Furthermore, decreases in the electrical properties were not observed in the composite films when they were bent up to 100 times at an angle of 180° and bent multiple times at an angle of 90°, clearly demonstrating their excellent mechanical flexibility. This study provides a straightforward method of fabricating highly flexible, lightweight, and conductive films, which have the potential to be used in high-performance soft electronic systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Handheld and automated ultrasonic spray deposition of conductive PEDOT:PSS films and their application in AC EL devices

    NARCIS (Netherlands)

    Ely, Fernando; Matsumoto, Agatha; Zoetebier, Bram; Peressinotto, Valdirene S.; Hirata, Marcelo Kioshi; de Sousa, Douglas A.; Maciel, Rubens

    2014-01-01

    In this contribution we explore the spray deposition technique to achieve smooth films based on the conductive polymer PEDOT:PSS. Two different spray systems were used and compared namely: (a) handheld airbrush and (b) automated ultrasonic spray system. For each system a number of parameters were

  9. Sheet resistance, transmittance, and chromatic property of CNTs coated with PEDOT:PSS films for transparent electrodes of touch screen panels

    International Nuclear Information System (INIS)

    Kim, Bu-Jong; Han, Sang-Hoon; Park, Jin-Seok

    2014-01-01

    This study demonstrates hybrid-type transparent electrodes based on carbon nanotubes (CNTs) that possess characteristics desirable for touch screen panels. This has been accomplished by depositing CNTs via spray-coating and then depositing thin conductive polymer (such as PEDOT:PSS) films on the CNTs via spin-coating. For all of the samples such as CNTs, PEDOT:PSS, and hybrid (i.e., PEDOT:PSS-coated CNTs), their surface morphologies, sheet resistances, visible transmittances, and chromatic properties are characterized as functions of their preparation conditions. In the PEDOT:PSS-coated CNTs, the PEDOT:PSS particles fill up the voids between tubes in CNTs, forming a conduction bridge for electron transfer and eventually decreasing the sheet resistance of the hybrid electrode. Also, the hybrid electrode reveals a superior color property compared with that of CNTs or the PEDOT:PSS single electrode due to the complementary color relation between CNTs and PEDOT:PSS. Experimental results show that the fabricated hybrid-type electrodes can simultaneously satisfy the requirements necessary for transparent electrodes of touch screen panels such as the sheet resistance requiring to be lower than 100 Ω/sq, visible transmittance higher than 80%, and yellowness approaching to zero. - Highlights: • Hybrid-type (PEDOT:PSS-coated CNTs) electrodes for touch panels are fabricated. • PEDOT:PSS films are coated via spin-coating on spray-deposited CNTs. • Hybrid electrodes are fabricated by varying the thickness of CNTs and PEDOT:PSS. • The resistance, transmittance, and color properties have been analyzed. • Hybrid electrodes satisfy electrical and optical properties for touch panels

  10. Sheet resistance, transmittance, and chromatic property of CNTs coated with PEDOT:PSS films for transparent electrodes of touch screen panels

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bu-Jong; Han, Sang-Hoon; Park, Jin-Seok

    2014-12-01

    This study demonstrates hybrid-type transparent electrodes based on carbon nanotubes (CNTs) that possess characteristics desirable for touch screen panels. This has been accomplished by depositing CNTs via spray-coating and then depositing thin conductive polymer (such as PEDOT:PSS) films on the CNTs via spin-coating. For all of the samples such as CNTs, PEDOT:PSS, and hybrid (i.e., PEDOT:PSS-coated CNTs), their surface morphologies, sheet resistances, visible transmittances, and chromatic properties are characterized as functions of their preparation conditions. In the PEDOT:PSS-coated CNTs, the PEDOT:PSS particles fill up the voids between tubes in CNTs, forming a conduction bridge for electron transfer and eventually decreasing the sheet resistance of the hybrid electrode. Also, the hybrid electrode reveals a superior color property compared with that of CNTs or the PEDOT:PSS single electrode due to the complementary color relation between CNTs and PEDOT:PSS. Experimental results show that the fabricated hybrid-type electrodes can simultaneously satisfy the requirements necessary for transparent electrodes of touch screen panels such as the sheet resistance requiring to be lower than 100 Ω/sq, visible transmittance higher than 80%, and yellowness approaching to zero. - Highlights: • Hybrid-type (PEDOT:PSS-coated CNTs) electrodes for touch panels are fabricated. • PEDOT:PSS films are coated via spin-coating on spray-deposited CNTs. • Hybrid electrodes are fabricated by varying the thickness of CNTs and PEDOT:PSS. • The resistance, transmittance, and color properties have been analyzed. • Hybrid electrodes satisfy electrical and optical properties for touch panels.

  11. Modification of the Highly Conductive PEDOT:PSS Layer for Use in Silver Nanogrid Electrodes for Flexible Inverted Polymer Solar Cells.

    Science.gov (United States)

    Wang, Jie; Fei, Fei; Luo, Qun; Nie, Shuhong; Wu, Na; Chen, Xiaolian; Su, Wenming; Li, Yuanjie; Ma, Chang-Qi

    2017-03-01

    Silver nanogrid based flexible transparent electrode is recognized as the most promising alternative to ITO electrode for organic electronics, owing to its low production cost and excellent flexibility. Typically, a highly conductive thin film coating layer, such as highly conductive PEDOT:PSS (HC-PEDOT:PSS) is usually deposited onto the Ag-grid electrode to smooth the surface and to minimize the sheet resistance. In this paper, we found that inverted flexible polymer solar cells with structure of Ag-grid/HC-PEDOT:PSS/ZnO/photoactive layer/MoO 3 /Al generally exhibits strong S-shaped J-V curves, which could be eliminated by light-soaking treatment. Kelvin probe force microscope (KPFM) measurement proved that a large work function (WF) difference (0.70 eV) between HC-PEDOT:PSS and ZnO is the main reason for the formation of S-shape. White light soaking of the Ag-grid/HC-PEDOT:PSS gradually decreased the WF of HC-PEDOT:PSS from 5.10 to 4.60 eV, leading to a reduced WF difference between HC-PEDOT:PSS and ZnO from 0.70 to 0.38 eV. Such a WF difference decrease was believed to be the working mechanism for the light-soaking effect in this flexible device. Based on this finding, the HC-PEDOT:PSS solution was then modified by doping with polyethylenimine (PEI) and aqueous ammonia. The modified PEDOT:PSS film is characteristic of adjusting WF through varying PEI doping concentrations. By using such a modified PEDOT:PSS layer, light-soaking-free flexible inverted polymer solar cell with a power conversion efficiency of 6.58% was achieved for PTB7-Th:PC 71 BM cells. The current work provides a useful guideline for interfacial modification for Ag-grid based flexible electrode.

  12. Development and Validation of the Coping with Acculturative Stress in American Schools (Casas-A) Scale on a Latino Adolescent Sample

    Science.gov (United States)

    Castro-Olivo, Sara M.; Palardy, Gregory J.; Albeg, Loren; Williamson, Ariel A.

    2014-01-01

    The psychometric properties of the Coping With Acculturative Stress in American Schools (CASAS-A) scale were examined using a sample of 148 Latino middle school students. CASAS-A is a self-report scale designed to identify students in need of culturally responsive social-emotional interventions due to having high levels of school-related…

  13. High performance silicon–organic hybrid solar cells via improving conductivity of PEDOT:PSS with reduced graphene oxide

    International Nuclear Information System (INIS)

    Jiang, Xinyu; Wang, Zilei; Han, Wenhui; Liu, Qiming; Lu, Shuqi; Wen, Yuxiang; Hou, Juan; Huang, Fei; Peng, Shanglong; He, Deyan; Cao, Guozhong

    2017-01-01

    Highlights: • The fabricated Si–organic hybrid solar cells with 2 mg/ml rGO addition yielded a power conversion efficiency of 11.95% with a J_s_c of 31.94 mA cm"−"2, a V_o_c of 579 mV and a FF of 0.648, about 27.8% increase from 9.35% in pristine hybrid solar cells. • The electrical conductivity of PEDOT:PSS improved 35% when appropriate amount rGO was added to PEDOT:PSS, the electron recombination at the junction interface of the device was suppressed by the appropriate amount rGO flakes addition. • The rGO flakes also serve as an antireflection coating to further reduce the reflectance in the wavelength range of 300–550 nm, leading to further enhanced performances of hybrid solar cells. - Abstract: The optical and electrical properties of PEDOT:PSS organic layer play a very important role in determining the power conversion efficiency (PCE) of Si–organic hybrid solar cells (HSCs). In the present study, properties of PEDOT:PSS thin films with reduced graphene oxide (rGO) and their impacts on the performances of the resultant Si–organic HSCs have been systematically investigated. The electrical conductivity of PEDOT:PSS improved 35% when rGO was added to PEDOT:PSS, and the fabricated HSCs with 2 mg/ml rGO addition yielded an PCE of 11.95% with a J_s_c of 31.94 mA cm"−"2, a V_o_c of 579 mV and a FF of 0.648. However, excess rGO would deteriorate the solar cells performances and it might create additional defects and prevent carriers being collected. The Raman spectroscopy, sheet resistance and EQE analyses with rGO suggested that the interaction between the conductive rGO flakes and the aromatic PEDOT most probably not only provide additional charge transport pathways in hole transport layer to improve carrier mobility leading to a higher carrier collection efficiency, but also suppress the electron recombination at the junction interface. In addition, the rGO serve as an antireflection coating to reduce the reflectance of PEDOT:PSS thin film

  14. High performance silicon–organic hybrid solar cells via improving conductivity of PEDOT:PSS with reduced graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xinyu; Wang, Zilei; Han, Wenhui; Liu, Qiming; Lu, Shuqi; Wen, Yuxiang [School of Physical Science and Technology, Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Hou, Juan [School of Science, Key Laboratory of Ecophysics, Shihezi University, Xinjiang 832003 (China); Huang, Fei [Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195-2120 (United States); Peng, Shanglong, E-mail: pengshl@lzu.edu.cn [School of Physical Science and Technology, Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); He, Deyan [School of Physical Science and Technology, Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Cao, Guozhong, E-mail: gzcao@u.washington.edu [Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195-2120 (United States)

    2017-06-15

    Highlights: • The fabricated Si–organic hybrid solar cells with 2 mg/ml rGO addition yielded a power conversion efficiency of 11.95% with a J{sub sc} of 31.94 mA cm{sup −2}, a V{sub oc} of 579 mV and a FF of 0.648, about 27.8% increase from 9.35% in pristine hybrid solar cells. • The electrical conductivity of PEDOT:PSS improved 35% when appropriate amount rGO was added to PEDOT:PSS, the electron recombination at the junction interface of the device was suppressed by the appropriate amount rGO flakes addition. • The rGO flakes also serve as an antireflection coating to further reduce the reflectance in the wavelength range of 300–550 nm, leading to further enhanced performances of hybrid solar cells. - Abstract: The optical and electrical properties of PEDOT:PSS organic layer play a very important role in determining the power conversion efficiency (PCE) of Si–organic hybrid solar cells (HSCs). In the present study, properties of PEDOT:PSS thin films with reduced graphene oxide (rGO) and their impacts on the performances of the resultant Si–organic HSCs have been systematically investigated. The electrical conductivity of PEDOT:PSS improved 35% when rGO was added to PEDOT:PSS, and the fabricated HSCs with 2 mg/ml rGO addition yielded an PCE of 11.95% with a J{sub sc} of 31.94 mA cm{sup −2}, a V{sub oc} of 579 mV and a FF of 0.648. However, excess rGO would deteriorate the solar cells performances and it might create additional defects and prevent carriers being collected. The Raman spectroscopy, sheet resistance and EQE analyses with rGO suggested that the interaction between the conductive rGO flakes and the aromatic PEDOT most probably not only provide additional charge transport pathways in hole transport layer to improve carrier mobility leading to a higher carrier collection efficiency, but also suppress the electron recombination at the junction interface. In addition, the rGO serve as an antireflection coating to reduce the reflectance of

  15. Positive Effects of a Stress Reduction Program Based on Mindfulness Meditation in Brazilian Nursing Professionals: Qualitative and Quantitative Evaluation.

    Science.gov (United States)

    dos Santos, Teresa Maria; Kozasa, Elisa Harumi; Carmagnani, Isabel Sampaio; Tanaka, Luiza Hiromi; Lacerda, Shirley Silva; Nogueira-Martins, Luiz Antonio

    2016-01-01

    Mindfulness meditation has been shown to effectively mitigate the negative effects of stress among nursing professionals, but in countries like Brazil, these practices are relatively unexplored. To evaluate the effects of a Stress Reduction Program (SRP) including mindfulness and loving kindness meditation among nursing professionals working in a Brazilian hospital setting. Pilot study with a mixed model using quantitative and qualitative methods was used to evaluate a group of participants. The quantitative data were analyzed at three different time points: pre-intervention, post-intervention, and follow-up. The qualitative data were analyzed at post-intervention. Hospital São Paulo (Brazil). Sample 13 nursing professionals, including nurses, technicians, and nursing assistants working in a hospital. Participants underwent mindfulness and loving kindness meditation during a period of six weeks. Perceived Stress Scale (PSS), Maslach Burnout Inventory (MBI), Beck Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), Satisfaction With Life Scale (SWLS), Self-Compassion Scale (SCS), WHOQOL-BREF quality of life assessment, and Work Stress Scale (WSS). Qualitative data were collected via a group interview following six weeks participation in the SRP. The quantitative analyses revealed a significant reduction (P stress, burnout, depression, and anxiety (trait). These variables showed no significant differences between post-intervention and follow-up scores. The WHOQOL-BREF revealed significant increase (P nursing activities. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Large scale parallel FEM computations of far/near stress field changes in rocks

    Czech Academy of Sciences Publication Activity Database

    Blaheta, Radim; Byczanski, Petr; Jakl, Ondřej; Kohut, Roman; Kolcun, Alexej; Krečmer, Karel; Starý, Jiří

    2006-01-01

    Roč. 22, č. 4 (2006), s. 449-459 ISSN 0167-739X R&D Projects: GA ČR(CZ) GA105/02/0492; GA AV ČR(CZ) 1ET400300415 Institutional research plan: CEZ:AV0Z30860518 Keywords : large scale finite element analysis Subject RIV: BA - General Mathematics Impact factor: 0.722, year: 2006

  17. Flexible, high performance Two-Ply Yarn Supercapacitors based on irradiated Carbon Nanotube Yarn and PEDOT/PSS

    International Nuclear Information System (INIS)

    Su, Fenghua; Miao, Menghe

    2014-01-01

    Graphical abstract: - Highlights: • Two-ply supercapacitors based on CNT yarn were prepared by a simple method. • The two-ply supercapacitors are high-performance, flexible and thread-like. • Gamma irradiation of CNT yarn improves the capacitance of the resulting supercapacitor. • PEDOT/PSS coated on the yarn surface further improve the capacitance of supercapacitors. • The two-ply supercapacitors can be easily woven or knitted into conventional textile fabrics. - Abstract: We present a simple design and a fabrication method for a high-performance, flexible, two-ply yarn supercapacitor based on irradiated CNT yarn and conductive polymer Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT/PSS). The CNT yarn is treated with gamma irradiation and the yarn surface is coated with the PEDOT/PSS to improve the energy storage capacitance of the as-spun yarn supercapacitor. A layer of PVA gel is coated on the surfaces of the CNT yarn and the composite yarn to form a separation layer containing electrolyte. The results show that the gamma irradiation greatly increases the electrical conductivity and improved the gram capacitance of the as-spun CNT two-ply yarn supercapacitor. The coating of PEDOT/PSS on the surface of the pure and irradiated CNT yarns further significantly improves the capacitance of the supercapacitors. The two-ply yarn supercapacitor constructed from the irradiation CNT yarn coated by PEDOT/PSS exhibits the large capacitance and high cyclic charge-discharge stability. Moreover, these two-ply yarn supercapacitors with fine diameters are highly flexible and can be easily woven or knitted into textile fabrics for uses in wearable electronics

  18. Adaptation to Portuguese of the Depression, Anxiety and Stress Scales (DASS Adaptación para la lengua portuguesa de la Depression, Anxiety and Stress Scale (DASS Adaptação para a língua portuguesa da Depression, Anxiety and Stress Scale (DASS

    Directory of Open Access Journals (Sweden)

    João Luís Alves Apóstolo

    2006-12-01

    Full Text Available Objective: to adapt to Portuguese, of Portugal, the Depression, Anxiety and Stress Scales, a 21-item short scale (DASS 21, designed to measure depression, anxiety and stress. Method: After translation and back-translation with the help of experts, the DASS 21 was administered to patients in external psychiatry consults (N=101, and its internal consistency, construct validity and concurrent validity were measured. Results: The DASS 21 properties certify its quality to measure emotional states. The instrument reveals good internal consistency. Factorial analysis shows that the two-factor structure is more adequate. The first factor groups most of the items that theoretically assess anxiety and stress, and the second groups most of the items that assess depression, explaining, on the whole, 58.54% of total variance. The strong positive correlation between the DASS 21 and the Hospital Anxiety and Depression scale (HAD confirms the hypothesis regarding the criterion validity, however, revealing fragilities as to the divergence between theoretically different constructs.Objetivo: adaptar a la lengua portuguesa, de Portugal, la Depression, Anxiety and Stress Scale, versión corta de 21 ítems, (DASS-21, que permite evaluar depresión, ansiedad y estrés. Método: Después de haber sido traducida y retrovertida, con la ayuda de peritos, la DASS-21 fue administrada a enfermos en consulta externa de psiquiatría (N=101, y fue evaluada la consistencia interna, la validez de constructo y la validez concurrente. Resultados: Las propiedades de la DASS-21 atestiguan su calidad para evaluar estados emocionales. El instrumento reveló buena consistencia interna. El análisis factorial muestra que la estructura de dos factores es la más ajustada. El primer factor agrupa la mayoría de los ítems que teóricamente evalúan ansiedad y estrés, y el segundo agrupa la mayoría de los ítems que evalúan depresión, explicando en su conjunto el 58,54% de la variaci

  19. The contribution of personal and seniority variables to the presence of stress symptoms among Israeli UAV operators.

    Science.gov (United States)

    Gal, Shiri; Shelef, Leah; Oz, Idit; Yavnai, Nirit; Carmon, Erez; Gordon, Shirley

    2016-01-01

    The exposure to war scenes via screens, despite offering a degree of detachment, can be stressful for the operator. The aim of the current study is to examine the existence of anxiety, depression, and post traumatic stress disorder (PTSD) symptoms among unmanned aerial vehicle (UAV) Israeli operators. Participants comprised 41 UAV operators (87.2% male), aged 22-38 ( M age  = 26.05, SD  = 3.54). Most (78.0%) reported having viewed battlefield scenes. All participants completed a total of five questionnaires: Beck Depression Inventory, State-Trait Anxiety Inventory, and three questionnaires of PTSD: Post Trauma Questionnaire (CAPS), the Post-Traumatic Cognition Inventory (CTPI), and the Post-Traumatic Symptom Scale (PSS). Mean scores of depression and anxiety were found significantly lower than diagnosis cut-off points ( p  UAV operators are highly beneficial for preventing psychopathology.

  20. Reliability and Validity of the Korean Version of the Symptom Checklist-Post-Traumatic Stress Disorder Scale

    Science.gov (United States)

    2016-01-01

    The Symptom Checklist - Post-Traumatic Stress Disorder Scale (SCL-PTSD), also known as Crime-Related PTSD Scale has been validated in survivors of interpersonal trauma in the general population. However, the psychometric properties have not been investigated in a clinical setting for patients with PTSD from diverse traumatic events. This study investigates the reliability and validity of the Korean version of the SCL-PTSD among 104 psychiatric outpatients with PTSD, caused by interpersonal (n = 50) or non-interpersonal trauma (n = 54). Self-report data of the SCL-PTSD, Beck Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), and Impact of Events Scale-Revised (IES-R) were gathered. The Korean version of the SCL-PTSD showed excellent internal consistency and moderate-to-good four-week temporal stability in both the interpersonal and non-interpersonal trauma groups. In comparison with other diagnostic groups, the scores of the SCL-PTSD were significantly higher compared to those of adjustment disorder, depression, other anxiety disorders, and schizophrenia, demonstrating its criteria-related validity. Convergent validity was confirmed because the scores of the SCL-PTSD were significantly correlated with BDI, SAI and TAI scores. Concurrent validity was demonstrated by significant correlation with the IES-R score. This study demonstrated the favorable psychometric prosperities of the Korean version of the SCL-PTSD, supporting its use in clinical research and practice. PMID:27134501

  1. Stress.

    Science.gov (United States)

    Chambers, David W

    2008-01-01

    We all experience stress as a regular, and sometimes damaging and sometimes useful, part of our daily lives. In our normal ups and downs, we have our share of exhaustion, despondency, and outrage--matched with their corresponding positive moods. But burnout and workaholism are different. They are chronic, dysfunctional, self-reinforcing, life-shortening habits. Dentists, nurses, teachers, ministers, social workers, and entertainers are especially susceptible to burnout; not because they are hard-working professionals (they tend to be), but because they are caring perfectionists who share control for the success of what they do with others and perform under the scrutiny of their colleagues (they tend to). Workaholics are also trapped in self-sealing cycles, but the elements are ever-receding visions of control and using constant activity as a barrier against facing reality. This essay explores the symptoms, mechanisms, causes, and successful coping strategies for burnout and workaholism. It also takes a look at the general stress response on the physiological level and at some of the damage American society inflicts on itself.

  2. Tool for Predicting Medical Student Burnout From Sustained Stress Levels: Factor Analysis of the Medical Education Hassles Scale-R.

    Science.gov (United States)

    Johnson, Jane C; Degenhardt, Brian F; Smith, Carol K; Wolf, Thomas M; Peterson, D Fred

    2018-03-01

    Acute stress during medical school affects the health of students and is associated with burnout. The Medical Education Hassles Scale-R (MEHS-R) is designed to measure acute stress among medical students. Researchers using the MEHS-R primarily report overall hassles scores, which are unable to discriminate between different categories of hassles encountered. The present study examined the factor structure of the MEHS-R to identify subscales that would be useful to categorize hassles for research and assessment purposes. Longitudinal, observational study. Two osteopathic medical schools. Five hundred six first-year medical students. The MEHS-R was administered at orientation and 9 to 10 times throughout the first year, classified into examination, vacation, and routine medical school activity periods. Students rated the 101 items on a 4-point scale (0=none to 3=a great deal) to indicate how much of a hassle each item had been during the previous week. Demographic subgroups were males, females, married students, single students, whites, and ethnic minorities. Exploratory factor analysis was conducted on data collected at the first school during orientation. Seven subscales were identified: Academic and Time Pressures, Financial, Social, External Influences, Day-to-Day Functioning, Relationships With Immediate Family, and Health. Cronbach α were ≥0.75. Stability of these subscales was examined using confirmatory factor analysis. Both of the fit indices used indicated the 7-subscale model for the MEHS-R adequately fit the data obtained during examination and routine medical school activity periods, one fit index indicated adequate fit for the vacation period, and neither indicated adequate fit for the data from the second school. Of the 7 subscales, 5 had a strong correspondence with categories identified by the scale developers. Fit indices also indicated the 7-subscale model was adequately generalizable to the demographic subgroups with the exception of the ethnic

  3. The thrill of being violent as an antidote to posttraumatic stress disorder in Rwandese genocide perpetrators

    Directory of Open Access Journals (Sweden)

    Roland Weierstall

    2011-11-01

    Full Text Available The cumulative exposure to life-threatening events increases the risk for posttraumatic stress disorder (PTSD. However, over the course of evolutionary adaptation, intra-species killing may have also evolved as an inborn strategy leading to greater reproductive success. Assuming that homicide has evolved as a profitable strategy in humans, a protective mechanism must prevent the perpetrator from getting traumatised by self-initiated violent acts. We thus postulate an inverse relation between a person's propensity toward violence and PTSD. We surveyed a sample of 269 Rwandan prisoners who were accused or convicted for crimes related to the 1994 genocide. In structured interviews we assessed traumatic event types, types of crimes committed, the person's appetitive violence experience with the Appetitive Aggression Scale (AAS and PTSD symptom severity with the PSS-I. Using path-analysis, we found a dose-response effect between the exposure to traumatic events and the PTSD symptom severity (PSS-I. Moreover, participants who had reported that they committed more types of crimes demonstrated a higher AAS score. In turn, higher AAS scores predicted lower PTSD symptom severity scores. This study provides first empirical support that the victim's struggling can be an essential rewarding cue for perpetrators. The results also suggest that an appetitive aggression can inhibit PTSD and trauma-related symptoms in perpetrators and prevent perpetrators from getting traumatised by their own atrocities.

  4. Measuring Multiple Minority Stress: The LGBT People of Color Microaggressions Scale

    Science.gov (United States)

    Balsam, Kimberly F.; Molina, Yamile; Beadnell, Blair; Simoni, Jane; Walters, Karina

    2014-01-01

    Lesbian, gay, and bisexual individuals who are also racial/ethnic minorities (LGBT-POC) are a multiply marginalized population subject to microaggressions associated with both racism and heterosexism. To date, research on this population has been hampered by the lack of a measurement tool to assess the unique experiences associated with the intersection of these oppressions. To address this gap in the literature, we conducted a three-phase, mixed method empirical study to assess microaggressions among LGBT-POC. The LGBT People of Color Microaggressions Scale is an 18-item self-report scale assessing the unique types of microaggressions experienced by ethnic minority LGBT adults. The measure includes three subscales: (a) Racism in LGBT communities, (b) Heterosexism in Racial/Ethnic Minority Communities, and (c) Racism in Dating and Close Relationships, that are theoretically consistent with prior literature on racial/ethnic minority LGBTs and have strong psychometric properties including internal consistency and construct validity in terms of correlations with measures of psychological distress and LGBT-identity variables. Men scored higher on the LGBT-PCMS than women, lesbians and gay men scored higher than bisexual women and men, and Asian Americans scored higher than African Americans and Latina/os. PMID:21604840

  5. Stress distribution retrieval in granular materials: A multi-scale model and digital image correlation measurements

    Science.gov (United States)

    Bruno, Luigi; Decuzzi, Paolo; Gentile, Francesco

    2016-01-01

    The promise of nanotechnology lies in the possibility of engineering matter on the nanoscale and creating technological interfaces that, because of their small scales, may directly interact with biological objects, creating new strategies for the treatment of pathologies that are otherwise beyond the reach of conventional medicine. Nanotechnology is inherently a multiscale, multiphenomena challenge. Fundamental understanding and highly accurate predictive methods are critical to successful manufacturing of nanostructured materials, bio/mechanical devices and systems. In biomedical engineering, and in the mechanical analysis of biological tissues, classical continuum approaches are routinely utilized, even if these disregard the discrete nature of tissues, that are an interpenetrating network of a matrix (the extra cellular matrix, ECM) and a generally large but finite number of cells with a size falling in the micrometer range. Here, we introduce a nano-mechanical theory that accounts for the-non continuum nature of bio systems and other discrete systems. This discrete field theory, doublet mechanics (DM), is a technique to model the mechanical behavior of materials over multiple scales, ranging from some millimeters down to few nanometers. In the paper, we use this theory to predict the response of a granular material to an external applied load. Such a representation is extremely attractive in modeling biological tissues which may be considered as a spatial set of a large number of particulate (cells) dispersed in an extracellular matrix. Possibly more important of this, using digital image correlation (DIC) optical methods, we provide an experimental verification of the model.

  6. The role of perceived threat during emergency department cardiac evaluation and the age-posttraumatic stress disorder link.

    Science.gov (United States)

    Meli, Laura; Kautz, Marin; Julian, Jacob; Edmondson, Donald; Sumner, Jennifer A

    2018-06-01

    Evaluation for acute coronary syndrome (ACS) can trigger posttraumatic stress symptoms (PSS). Research suggests that younger, versus older, individuals may be at elevated risk for PSS after ACS evaluation. It has been proposed that younger individuals may be at greater risk because they perceive the suspected ACS event as more threatening than their older counterparts; however, this has yet to be tested. We examined whether perceived threat during ACS evaluation mediated the association between age and PSS after ACS evaluation in an observational cohort study of patients presenting to the emergency department (ED) with suspected ACS. Demographics and perceived threat were assessed in the ED. PSS were measured upon inpatient transfer or by phone 3 days later. The analytic sample comprised 871 adult participants. Multiple linear regression was used to examine (1) associations of age and perceived threat with PSS and (2) whether perceived threat mediated the association. Bootstrapping with percentile-based confidence intervals (CIs) was used to test the indirect effect. Each year of age was associated with lower PSS (b = - 0.12, p age was associated with lower perceived threat during ACS evaluation (b = - 0.05, p age differences in PSS development risk and the potential impact of age on threat perceptions may help inform ED treatment.

  7. Validação da escala de estresse no trabalho Validation of the work stress scale

    Directory of Open Access Journals (Sweden)

    Tatiane Paschoal

    2004-04-01

    Full Text Available Este trabalho teve como objetivo construir e validar um instrumento de estresse ocupacional geral, de fácil aplicação e que pudesse ser utilizado em diversos ambientes de trabalho e para ocupações variadas. A Escala de Estresse no Trabalho (EET, inicialmente composta por 31 itens, foi aplicada a 437 trabalhadores de diferentes organizações, públicas e privadas, sendo 249 homens e 188 mulheres. A análise fatorial revelou a existência de um único fator que, após eliminação de itens com carga fatorial abaixo de 0,45, ficou composto por 23 itens e obteve um coeficiente alfa de Cronbach equivalente a 0,91. Uma versão reduzida da escala, com 13 itens e alfa de 0,85 foi proposta. Com base nos parâmetros psicométricos satisfatórios da EET, conclui-se que esta é uma alternativa para investigações empíricas e trabalhos aplicados em organizações, podendo orientar medidas que visem à qualidade de vida dos trabalhadores.The objective of this study was to develop and to validate a general instrument to evaluate occupational stress, easily administered, used in different work environments and for a variety of occupations. The Work Stress Scale (WSS initially composed of 31 items was applied to 437 workers, 249 men and 188 women, of public and private organizations. The factor analysis detected only one factor. After the elimination of the items with a factor loading below .45, the final version of the scale was composed of 23 items and had a Cronbach's coefficient of .91. A reduced version of the scale with 13 items and a Cronbach's coefficient of .85 has been proposed. Based on the satisfactory psychometric parameters of the scale, it is concluded that the WSS is useful as an alternative in empirical investigations and organizational diagnostics. The results obtained can be useful indicators for organizational decisions in relation to the life quality of the workers.

  8. The Optical Properties of Thin Film Reduced Graphene Oxide/Poly (3,4 Ethylenedioxtriophene):Poly (Styrene Sulfonate)(PEDOT:PSS) Fabricated by Spin Coating

    Science.gov (United States)

    Rokmana, Arinta W.; Asriani, A.; Suhendar, H.; Triyana, K.; Kusumaatmaja, A.; Santoso, I.

    2018-04-01

    Reduced Graphene Oxide (rGO) has been successfully synthesized from Graphite powder through chemical process using modified Hummers method by removing NaNO3 from reaction formula. Hydrazine hydrate 80 wt% has been chosen as reductor to eliminate the epoxy group in GO. FTIR and Uv-Vis spectroscopy result showed that Graphene Oxide (GO) and rGO were formed. Our produced rGO then used to fabricated the composite thin film rGO/PEDOT:PSS by spin coating at room temperature. The optical constant of thin film rGO/PEDOT:PSS were calculated from the absorbance spectrum of Uv-Visible spectra. The result showed that the value of coefficient absorbance of rGO dropped from 4.7×106 m-1 to 1.3×106 m-1 after doped with 0.02 mL PEDOT:PSS, then increase with the addition volume concentration of PEDOT:PSS. The value of extinction coefficient decrease from 0.31 to 0.08 after rGO doped with 0.02 ml PEDOT:PSS and then increase with the addition concentration of PEDOT:PSS. Our result show that thin film rGO/PEDOT:PSS was more transparent than that of thin film rGO.

  9. Fabrication of flexible conductive films derived from poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonic acid) (PEDOT:PSS) on the nonwoven fabrics substrate

    International Nuclear Information System (INIS)

    Wu, Chieh-Han; Shen, Hsiu-Ping; Don, Trong-Ming; Chiu, Wen-Yen

    2013-01-01

    In this research, conducting poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonic acid) (PEDOT:PSS) aqueous dispersion was synthesized at first via chemical oxidative polymerization and followed by mixing it with poly(styrene-r-butyl acrylate) P(St-BA) aqueous latex, creating a conductive material with outstanding stretchability. The elastic conductive composite were then film formed on the glass and poly(ethylene terephthalate) (PET) nonwoven fabric substrate by spin coating and dip coating, respectively. Composite films with various contents of PEDOT:PSS polymer (10–100 wt.%) had been prepared. From the conductivity measurements, the conductivity was still kept as high as 88 S cm −1 even the PEDOT:PSS content was lowered to 10 wt.%. Furthermore, the elasticity of conductive films on the PET-nonwoven fabric substrate was evaluated by the 180° bending test repeating 100 times. With introducing soft P(St-BA) material in the PEDOT:PSS phase, the surface resistance increased merely 3–6 times after bending 100 times, while the surface resistance for pure PEDOT:PSS film could reach 18–20 times. - Highlights: • Flexible PEDOT:PSS based material had been coated on the PET-nonwoven fabrics. • The integrity of conductive circuit on fabrics was evaluated by bending test. • With adding rubbery material, the flexibility of PEDOT:PSS coating was enhanced

  10. Fabrication of flexible conductive films derived from poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonic acid) (PEDOT:PSS) on the nonwoven fabrics substrate

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chieh-Han [Institute of Polymer Science and Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Shen, Hsiu-Ping [Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Don, Trong-Ming, E-mail: tmdon@mail.tku.edu.tw [Department of Chemical and Materials Engineering, Tamkang University, New Taipei 251, Taiwan, ROC (China); Chiu, Wen-Yen, E-mail: ycchiu@ntu.edu.tw [Institute of Polymer Science and Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China)

    2013-12-16

    In this research, conducting poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonic acid) (PEDOT:PSS) aqueous dispersion was synthesized at first via chemical oxidative polymerization and followed by mixing it with poly(styrene-r-butyl acrylate) P(St-BA) aqueous latex, creating a conductive material with outstanding stretchability. The elastic conductive composite were then film formed on the glass and poly(ethylene terephthalate) (PET) nonwoven fabric substrate by spin coating and dip coating, respectively. Composite films with various contents of PEDOT:PSS polymer (10–100 wt.%) had been prepared. From the conductivity measurements, the conductivity was still kept as high as 88 S cm{sup −1} even the PEDOT:PSS content was lowered to 10 wt.%. Furthermore, the elasticity of conductive films on the PET-nonwoven fabric substrate was evaluated by the 180° bending test repeating 100 times. With introducing soft P(St-BA) material in the PEDOT:PSS phase, the surface resistance increased merely 3–6 times after bending 100 times, while the surface resistance for pure PEDOT:PSS film could reach 18–20 times. - Highlights: • Flexible PEDOT:PSS based material had been coated on the PET-nonwoven fabrics. • The integrity of conductive circuit on fabrics was evaluated by bending test. • With adding rubbery material, the flexibility of PEDOT:PSS coating was enhanced.

  11. Linking Landscape-Scale Disturbances to Stress and Condition of Fish: Implications for Restoration and Conservation.

    Science.gov (United States)

    Jeffrey, Jennifer D; Hasler, Caleb T; Chapman, Jacqueline M; Cooke, Steven J; Suski, Cory D

    2015-10-01

    Humans have dramatically altered landscapes as a result of urban and agricultural development, which has led to decreases in the quality and quantity of habitats for animals. This is particularly the case for freshwater fish that reside in fluvial systems, given that changes to adjacent lands have direct impacts on the structure and function of watersheds. Because choices of habitat have physiological consequences for organisms, animals that occupy sub-optimal habitats may experience increased expenditure of energy or homeostatic overload that can cause negative outcomes for individuals and populations. With the imperiled and threatened status of many freshwater fish, there is a critical need to define relationships between land use, quality of the habitat, and physiological performance for resident fish as an aid to restoration and management. Here, we synthesize existing literature to relate variation in land use at the scale of watersheds to the physiological status of resident fish. This examination revealed that landscape-level disturbances can influence a host of physiological properties of resident fishes, ranging from cellular and genomic levels to the hormonal and whole-animal levels. More importantly, these physiological responses have been integrated into traditional field-based monitoring protocols to provide a mechanistic understanding of how organisms interact with their environment, and to enhance restoration. We also generated a conceptual model that provides a basis for relating landscape-level changes to physiological responses in fish. We conclude that physiological sampling of resident fish has the potential to assess the effects of landscape-scale disturbances on freshwater fish and to enhance restoration and conservation. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  12. Gate length scaling trends of drive current enhancement in CMOSFETs with dual stress overlayers and embedded-SiGe

    International Nuclear Information System (INIS)

    Flachowsky, S.; Wei, A.; Herrmann, T.; Illgen, R.; Horstmann, M.; Richter, R.; Salz, H.; Klix, W.; Stenzel, R.

    2008-01-01

    Strain engineering in MOSFETs using tensile nitride overlayer (TOL) films, compressive nitride overlayer (COL) films, and embedded-SiGe (eSiGe) is studied by extensive device experiments and numerical simulations. The scaling behavior was analyzed by gate length reduction down to 40 nm and it was found that drive current strongly depends on the device dimensions. The reduction of drain-current enhancement for short-channel devices can be attributed to two competing factors: shorter gate length devices have increased longitudinal and vertical stress components which should result in improved drain-currents. However, there is a larger degradation from external resistance as the gate length decreases, due to a larger voltage dropped across the external resistance. Adding an eSiGe stressor reduces the external resistance in the p-MOSFET, to the extent that the drive current improvement from COL continues to increase even down the shortest gate length studied. This is due to the reduced resistivity of SiGe itself and the SiGe valence band offset relative to Si, leading to a smaller silicide-active contact resistance. It demonstrates the advantage of combining eSiGe and COL, not only for increased stress, but also for parasitic resistance reduction to enable better COL drive current benefit

  13. Relationship between Maternal General and Specific-Pregnancy Stress, Anxiety, and Depression Symptoms and Pregnancy Outcome.

    Science.gov (United States)

    Hasanjanzadeh, Parvin; Faramarzi, Mahbobeh

    2017-04-01

    Despite scientific advances in the field of physical problems during pregnancy, the effect of mental problems on the health of pregnant women is still an important issue that needs further research. To determine the association of symptoms of stress, anxiety and depression during pregnancy and there effect on the pregnancy outcome. This was a descriptive correlational study. The population included 200 pregnant women of the urban and rural health centers affiliated with Babol University of Medical Sciences. There were 100 each in second and third trimester. Convenience multi stage cluster sampling was performed. Data collection was received through the Hospital Anxiety Depression Scale (HADS), Pregnancy Distress Questionnaire (PDQ), and Perceived Stress Scale (PSS-14) questionnaires. The correlation results showed a significant difference between variables of depression, stress, and anxiety with birth weight, birth height and head circumference and infants' APGAR score (prelationships on prediction of infant weight (B=-0.324), anxiety on prediction of infant height (B=-0.197), stress on prediction of head circumference (B=-0.350) and depression on prediction of APGAR score (B=-0.323) are effective (pdepression, anxiety and stress in pregnancy, and scheduling to avoid adverse consequences of the pregnancy outcome.

  14. Flexible nonvolatile memory devices based on Au/PMMA nanocomposites deposited on PEDOT:PSS/Ag nanowire hybrid electrodes

    International Nuclear Information System (INIS)

    Sung, Sihyun; Kim, Tae Whan

    2017-01-01

    Highlights: • Flexible nonvolatile memory (NVM) devices fabricated utilizing Au nanoparticles (AuNPs) embedded in a PMMA layer were fabricated. • The insertion of the PEDOT:PSS layer enhanced the surface uniformity of the AgNW bottom electrode, resulting in improved device performances. • Current-voltage curves for the Al/PMMA:AuNP/PEDOT:PSS/AgNW/PET devices showed clockwise current hysteresis behaviors. • ON/OFF ratio of 1 × 10 3 was maintained for retention times longer than 1 × 10 4 s. • Memory characteristics of the NVM devices before and after bending were similar. - Abstract: Flexible nonvolatile memory (NVM) devices fabricated utilizing Au nanoparticles (AuNPs) embedded in a poly(methylmethacrylate) (PMMA) layer were fabricated on a silver nanowire (AgNW) or a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/AgNW coated on poly(ethylene terephthalate) (PET) substrates. The transmittance and the sheet resistance of the PEDOT:PSS/AgNW hybrid layer were approximately 89% and 50 Ω/sq, respectively, which were comparable to the values for commercial indium-tin-oxide (ITO) electrodes. Current-voltage curves for the Al/PMMA:AuNP/PEDOT:PSS/AgNW/PET devices at 300 K showed clockwise current hysteresis behaviors due to the existence of the AuNPs. The endurance number of ON/OFF switching for the NVM devices was above 30 cycles. An ON/OFF ratio of 1 × 10 3 was maintained for retention times longer than 1 × 10 4 s. The maximum memory margins of the NVM devices before and after bending were approximately 3.4 × 10 3 and 1.4 × 10 3 , respectively. The retention times of the devices before and after bending remained same 1 × 10 4 s. The memory margin and the stability of flexible NVMs fabricated on AgNW electrodes were enhanced due to the embedded PEDOT:PSS buffer layer.

  15. Flexible nonvolatile memory devices based on Au/PMMA nanocomposites deposited on PEDOT:PSS/Ag nanowire hybrid electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Sihyun; Kim, Tae Whan, E-mail: twk@hanyang.ac.kr

    2017-07-31

    Highlights: • Flexible nonvolatile memory (NVM) devices fabricated utilizing Au nanoparticles (AuNPs) embedded in a PMMA layer were fabricated. • The insertion of the PEDOT:PSS layer enhanced the surface uniformity of the AgNW bottom electrode, resulting in improved device performances. • Current-voltage curves for the Al/PMMA:AuNP/PEDOT:PSS/AgNW/PET devices showed clockwise current hysteresis behaviors. • ON/OFF ratio of 1 × 10{sup 3} was maintained for retention times longer than 1 × 10{sup 4} s. • Memory characteristics of the NVM devices before and after bending were similar. - Abstract: Flexible nonvolatile memory (NVM) devices fabricated utilizing Au nanoparticles (AuNPs) embedded in a poly(methylmethacrylate) (PMMA) layer were fabricated on a silver nanowire (AgNW) or a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/AgNW coated on poly(ethylene terephthalate) (PET) substrates. The transmittance and the sheet resistance of the PEDOT:PSS/AgNW hybrid layer were approximately 89% and 50 Ω/sq, respectively, which were comparable to the values for commercial indium-tin-oxide (ITO) electrodes. Current-voltage curves for the Al/PMMA:AuNP/PEDOT:PSS/AgNW/PET devices at 300 K showed clockwise current hysteresis behaviors due to the existence of the AuNPs. The endurance number of ON/OFF switching for the NVM devices was above 30 cycles. An ON/OFF ratio of 1 × 10{sup 3} was maintained for retention times longer than 1 × 10{sup 4} s. The maximum memory margins of the NVM devices before and after bending were approximately 3.4 × 10{sup 3} and 1.4 × 10{sup 3}, respectively. The retention times of the devices before and after bending remained same 1 × 10{sup 4} s. The memory margin and the stability of flexible NVMs fabricated on AgNW electrodes were enhanced due to the embedded PEDOT:PSS buffer layer.

  16. Damage assessment in the stress field of scale, comparability and transferability

    Directory of Open Access Journals (Sweden)

    Assmann André

    2016-01-01

    Full Text Available Damage assessment is an important task requested in very different contexts. On the one hand very detailed studies are required for cost benefit analysis, on the other hand vulnerability and risk needs to be evaluated for political decisions and emergency situations (i.e. loss estimation of a large scale flood event. Even though a lot of studies have been performed and a lot of different methods are available by now, it is very difficult to use the results in the decision making process, as many methods are poorly described or are based on very special data, and therefore cannot be compared to each other. The attempt of regional (German federal state level standardizations based on very detailed object based approaches are shown. Additionally, a European wide data set for asset mapping is described and a set of application examples is given. It is designed to enable users to compare the impact of different types of hazard. To take it one step further, a global map for vulnerability is presented that can be used to set up a monetary based data set if detailed statistical data is not available. Every type of data set and methodology has its special tasks to fulfil but there is also a high demand for harmonisation and comparability between different studies to enable better decision making. The next demand on data sets and methodologies is to perform time sequence analyses, therefore all data sets and methods presented fulfil the requirement of being updated regularly.

  17. Surface stress and large-scale self-organization at organic-metal interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Pollinger, Florian

    2009-01-22

    The role of elastic interactions, particularly for the self-organized formation of periodically faceted interfaces, was investigated in this thesis for archetype organic-metal interfaces. The cantilever bending technique was applied to study the change of surface stress upon formation of the interface between 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) and Ag(111). The main focus of this work was on the investigation of the formation of the long-range ordered, self-organized faceted PTCDA/Ag(10 8 7) interface. Reciprocal space maps of this interface were recorded both by spot profile analysis low energy electron diffraction (SPA-LEED) and low energy electron microscopy (LEEM) in selected area LEED mode. Complementary to the reciprocal data, also microscopic real-space LEEM data were used to characterize the morphology of this interface. Six different facet faces ((111), (532), (743), (954), (13 9 5), and (542)) were observed for the preparation path of molecular adsorption on the substrate kept at 550 K. Facet-sensitive dark-field LEEM localized these facets to grow in homogeneous areas of microscopic extensions. The temperature-dependence of the interface formation was studied in a range between 418 K and 612 K in order to learn more about the kinetics of the process. Additional steeper facets of 27 inclination with respect to the (111) surface were observed in the low temperature regime. Furthermore, using facet-sensitive dark-field LEEM, spatial and size distributions of specific facets were studied for the different temperatures. Moreover, the facet dimensions were statistically analyzed. The total island size of the facets follows an exponential distribution, indicating a random growth mode in absence of any mutual facet interactions. While the length distribution of the facets also follows an exponential distribution, the width distribution is peaked, reflecting the high degree of lateral order. This anisotropy is temperature-dependent and occurs

  18. kISMET: Stress analysis and intermediate-scale hydraulic fracturing at the Sanford Underground Research Facility

    Science.gov (United States)

    Dobson, P. F.; Oldenburg, C. M.; Wu, Y.; Cook, P. J.; Kneafsey, T. J.; Nakagawa, S.; Ulrich, C.; Siler, D. L.; Guglielmi, Y.; Ajo Franklin, J. B.; Rutqvist, J.; Daley, T. M.; Birkholzer, J. T.; Wang, H. F.; Lord, N.; Haimson, B. C.; Sone, H.; Vigilante, P.; Roggenthen, W.; Doe, T.; Lee, M.; Ingraham, M. D.; Huang, H.; Mattson, E.; Johnson, T. C.; Zhou, J.; Zoback, M. D.; Morris, J.; White, J. A.; Johnson, P. A.; Coblentz, D. D.; Heise, J.

    2017-12-01

    In 2015, we established a field test facility at the Sanford Underground Research Facility (SURF), and in 2016 we carried out in situ hydraulic fracturing experiments to characterize the stress field, understand the effects of crystalline rock fabric on fracturing, and gain experience in monitoring using geophysical methods. The kISMET (permeability (k) and Induced Seismicity Management for Energy Technologies) project test site was established in the West Access Drift at the 4850 ft level, 1478 m below ground in phyllite of the Precambrian Poorman Formation. The kISMET team drilled and cored five near-vertical boreholes in a line on 3 m spacing, deviating the two outermost boreholes slightly to create a five-spot pattern around the test borehole centered in the test volume 40 m below the drift invert (floor) at a total depth of 1518 m. Laboratory measurements of core from the center test borehole showed P-wave velocity heterogeneity along each core indicating strong, fine-scale ( 1 cm or smaller) changes in the mechanical properties of the rock. Tensile strength ranges between 3‒7.5 MPa and 5‒12 MPa. Pre-fracturing numerical simulations with a discrete element code were carried out to predict fracture size and magnitude of microseismicity. Field measurements of the stress field were made using hydraulic fracturing, which produced remarkably uniformly oriented fractures suggesting rock fabric did not play a significant role in controlling fracture orientation. Electrical resistivity tomography (ERT) and continuous active seismic source monitoring (CASSM) were deployed in the four monitoring boreholes, and passive seismic accelerometer-based measurements in the West Access Drift were carried out during the generation of a larger fracture (so-called stimulation test). ERT was not able to detect the fracture created, nor did the accelerometers in the drift, but microseismicity was detected for the first (deepest) hydraulic-fracturing stress measurement. Analytical

  19. Three-dimensional shape transformations of hydrogel sheets induced by small-scale modulation of internal stresses

    Science.gov (United States)

    Wu, Zi Liang; Moshe, Michael; Greener, Jesse; Therien-Aubin, Heloise; Nie, Zhihong; Sharon, Eran; Kumacheva, Eugenia

    2013-03-01

    Although Nature has always been a common source of inspiration in the development of artificial materials, only recently has the ability of man-made materials to produce complex three-dimensional (3D) structures from two-dimensional sheets been explored. Here we present a new approach to the self-shaping of soft matter that mimics fibrous plant tissues by exploiting small-scale variations in the internal stresses to form three-dimensional morphologies. We design single-layer hydrogel sheets with chemically distinct, fibre-like regions that exhibit differential shrinkage and elastic moduli under the application of external stimulus. Using a planar-to-helical three-dimensional shape transformation as an example, we explore the relation between the internal architecture of the sheets and their transition to cylindrical and conical helices with specific structural characteristics. The ability to engineer multiple three-dimensional shape transformations determined by small-scale patterns in a hydrogel sheet represents a promising step in the development of programmable soft matter.