Generation-dependent charge carrier transport in Cu(In,Ga)Se 2/CdS/ZnO thin-film solar-cells

The following article appeared in Journal of Applied Physics 113.4 (2013): 044515 and may be found at http://scitation.aip.org/content/aip/journal/jap/113/4/10.1063/1.4788827Cross section electron-beam induced current (EBIC) and illumination- dependent current voltage (IV) measurements show that charge carrier transport in Cu(In,Ga)Se2 (CIGSe)/CdS/ZnO solar-cells is generation-dependent. We perform a detailed analysis of CIGSe solar cells with different CdS layer thicknesses and varying Ga-content in the absorber layer. In conjunction with numerical simulations, EBIC and IV data are used to develop a consistent model for charge and defect distributions with a focus on the heterojunction region. The best model to explain our experimental data is based on a p+ layer at the CIGSe/CdS interface leading to generation-dependent transport in EBIC at room temperature. Acceptor-type defect states at the CdS/ZnO interface cause a significant reduction of the photocurrent in the red-light illuminated IV characteristics at low temperatures (red kink effect). Shallow donor-type defect states at the p+ layer/CdS interface of some grains of the absorber layer are responsible for grain specific, i.e., spatially inhomogeneous, charge carrier transport observed in EBIC

Requirements for blockchain applications in manufacturing small and medium sized enterprises

Blockchain technology is rising towards the peak of inflated expectations according to Gartner's 2016 Hype Cycle for Emerging Technologies. A public ledger that enables low cost, near real-time, secure and timestamped transactions in a peer-to-peer network of participants without the need for a trusted third party offers great potentials for networks of cooperating companies of the manufacturing industry. Therefore, in this paper presents a definition and recent developments of the blockchain technology as well as evaluates existing applications with respect to the suitability for manufacturing companies. Furthermore, requirements for implementation of applications in manufacturing SMEs are derived to support the advancing digitization of industries

Impact of psychologically tailored hand hygiene interventions on nosocomial infections with multidrug-resistant organisms: results of the cluster-randomized controlled trial PSYGIENE

Abstract Background Professional hand hygiene compliance represents a multifaceted behaviour with various determinants. Thus, it has been proposed to apply psychological frameworks of behaviour change to its promotion. However, randomized controlled trials of such approaches, which also assess nosocomial infections (NIs), are rare. This study analyses data of the PSYGIENE-trial (PSYchological optimized hand hyGIENE promotion), which has shown improvements in compliance after interventions tailored based on the Health Action Process Approach (HAPA), on rates of NIs with multidrug-resistant organisms (MDROs). Methods A parallel-group cluster-randomized controlled trial was conducted on all 10 intensive care units and two hematopoietic stem cell transplantation units at Hannover Medical School, a German tertiary care hospital. Educational training sessions for physicians and nurses (individual-level intervention) and feedback discussions with clinical managers and head nurses (cluster-level) were implemented in 2013. In the “Tailoring”-arm (n = 6 wards), interventions were tailored based on HAPA-components, which were empirically assessed and addressed by behaviour change techniques. As active controls, n = 6 wards received untailored educational sessions of the local “Clean Care is Safer Care”-campaign (Aktion Saubere Hände: “ASH”-arm). From 2013 to 2015 compliance was assessed by observation following the World Health Organization, while alcohol-based hand rub usage (AHRU) and NIs with multidrug-resistant gram-negative bacteria, Methicillin-resistant Staphylococcus aureus or Vancomycin-resistant Enterococcus were assessed following national surveillance protocols. Data were analysed at cluster-level. Results In the “Tailoring”-arm, interventions led to a decrease of 0.497 MDRO-infections per 1000 inpatient days from 2013 to 2015 (p = 0.015). This trend was not found in the “ASH”-arm (− 0 . 022 infections; p = 0.899). These patterns corresponded inversely to the trends in compliance but not in AHRU. Conclusions While interventions tailored based on the HAPA-model did not lead to a significantly lower incidence rate of MDRO-infections compared to control wards, a significant reduction, compared to baseline, was found in the second follow-up year in the “Tailoring”- but not the "ASH"-arm. This indicates that HAPA-tailored hand hygiene interventions may contribute to the prevention of NIs with MDRO. Further research should focus on addressing compliance by interventions tailored not only to wards, but also leaders, teams, and individuals. Trial registration German Clinical Trials Register/International Clinical Trials Registry Platform, DRKS00010960. Registered 19 August 2016-Retrospectively registered, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00010960. http://apps.who.int/trialsearch/Trial2.aspx?TrialID=DRKS00010960

Determinants of orthopedic physicians’ self-reported compliance with surgical site infection prevention: results of the WACH-trial’s pilot survey on COM-B factors in a German university hospital

Background: Prevention of surgical site infections (SSIs), which due to their long-term consequences are especially critical in orthopedic surgery, entails compliance with over 20 individual measures. However, little is known about the psychosocial determinants of such compliance among orthopedic physicians, which impedes efforts to tailor implementation interventions to improve compliance. Thus, for this professional group, this pilot survey examined psychosocial determinants of self-reported compliance, which have been theoretically derived from the COM-B (Capability, Opportunity, Motivation and Behavior) model. Methods: In 2019, a cross-sectional survey was conducted in a tertiary care university orthopedic clinic in Hannover, Germany, as a pilot for the WACH-trial ('Wundinfektionen und Antibiotikaverbrauch in der Chirurgie' [Wound Infections and Antibiotics Consumption in Surgery]). Fifty-two physicians participated (38 surgeons, 14 anesthesiologists; response rate: 73.2%). The questionnaire assessed self-reported compliance with 26 SSI preventive measures, and its psychosocial determinants (COM-B). Statistical analyses included descriptive, correlational, and linear multiple regression modeling. Results: Self-reported compliance rates for individual measures varied from 53.8 to 100%, with overall compliance (defined for every participant as the mean of his or her self-reported rates for each individual measure) averaging at 88.9% (surgeons: 90%, anesthesiologists: 85.9%; p = 0.097). Of the components identified in factor analyses of the COM-B items, planning, i.e., self-formulated conditional plans to comply, was the least pronounced (mean = 4.3 on the 7-point Likert scale), while motivation was reported to be the strongest (mean = 6.3). Bi-variately, the overall compliance index co-varied with all four COM-B-components, i.e., capabilities (r = 0.512, p < 0.001), opportunities (r = 0.421, p = 0.002), planning (r = 0.378, p = 0.007), and motivation (r = 0.272, p = 0.051). After mutual adjustment and adjustment for type of physician and the number of measures respondents felt responsible for, the final backward regression model included capabilities (beta = 0.35, p = 0.015) and planning (beta = 0.29, p = 0.041) as COM-B-correlates. Conclusion: Though based on a small sample of orthopedic physicians in a single hospital (albeit in conjunction with a high survey response rate), this study found initial evidence for positive correlations between capabilities and planning skills with self-reported SSI preventive compliance in German orthopedic physicians. Analyses of the WACH-trial will further address the role of these factors in promoting SSI preventive compliance in orthopedic surgery