83 research outputs found

    Geographie an beruflichen Schulen in Baden-Württemberg zwischen Anspruch und Wirklichkeit – eine aktuelle Bestandsaufnahme von Innen- und Außenansichten

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    Das Schulfach Geographie steht immer wieder in der Diskussion um Stundenreduzierungen in den Bildungsplänen. Das berufliche Schulwesen spielt dabei häufig eine wichtige Vorreiterrolle. In dem Beitrag wird deshalb exemplarisch die aktuelle Situation des Faches Wirtschaftsgeographie an beruflichen Schulen in Baden-Württemberg dargestellt. Im Mittelpunkt steht dabei eine Befragung von Schülern, Eltern und Lehrern an kaufmännischen Gymnasien zu deren Ansichten über die Bedeutung des Faches und geographischer Fragestellungen im schulischen und außerschulischen Kontext. Demnach ist der öffentliche Ruf des Faches Geographie wesentlich besser als erwartet (befürchtet). Besonders die Bedeutung des Faches für die Umwelterziehung, die Orientierung im Raum und die Raumverhaltenskompetenz wird vielfach betont. Der Geographie wird damit eine zentrale Funktion beigemessen, die es in der öffentlichen Diskussion zu stärken gilt

    Origins of the open-circuit voltage in ternary organic solar cells and design rules for minimized voltage losses

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    The power conversion efficiency of ternary organic solar cells (TOSCs), consisting of one host binary blend and one guest component, remains limited by large voltage losses. The fundamental understanding of the open-circuit voltage (V OC) in TOSCs is controversial, limiting rational design of the guest component. In this study, we systematically investigate how the guest component affects the radiative and non-radiative related parts of V OC of a series of TOSCs using the detailed balanced principle. We highlight that the thermal population of charge-transfer and local exciton states provided by the guest binary blend (that is, the guest-component-based binary blend) has a significant influence on the non-radiative voltage losses. Ultimately, we provide two design rules for enhancing the V OC in TOSCs: high emission yield for the guest binary blend and similar charge-transfer-state energies for host/guest binary blends; high miscibility of the guest component with the low gap component in the host binary blend

    Strong light-matter coupling for reduced photon energy losses in organic photovoltaics

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    Funding: Volkswagen Foundation (no.93404) (MCG), individual fellowship of the DeutscheForschungsgemeinschaft (404587082) (AM).Strong light-matter coupling can re-arrange the exciton energies in organic semiconductors. Here, we exploit strong coupling by embedding a fullerene-free organic solar cell (OSC) photo-active layer into an optical microcavity, leading to the formation of polariton peaks and a red-shift of the optical gap. At the same time, the open-circuit voltage of the device remains unaffected. This leads to reduced photon energy losses for the low-energy polaritons and a steepening of the absorption edge. While strong coupling reduces the optical gap, the energy of the charge-transfer state is not affected for large driving force donor-acceptor systems. Interestingly, this implies that strong coupling can be exploited in OSCs to reduce the driving force for electron transfer, without chemical or microstructural modifications of the photo-active layer. Our work demonstrates that the processes determining voltage losses in OSCs can now be tuned, and reduced to unprecedented values, simply by manipulating the device architecture.Publisher PDFPeer reviewe

    Comparative Study of the Sensitivity of Different Diagnostic Methods for the Laboratory Diagnosis of Buruli Ulcer Disease

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    Background. Several diagnostic laboratory methods are available for case confirmation of Buruli ulcer disease. This study assessed the sensitivity of various diagnostic tests in relation to clinical presentation of the disease, type of diagnostic specimen, and treatment history. Methods. Swab samples, 3-mm punch biopsy tissue specimens, and surgically excised tissue specimens from 384 individuals with suspected Buruli ulcer disease were obtained at 9 different study sites in Ghana and were evaluated with dry reagent-based polymerase chain reaction (PCR), microscopic examination, culture, and histopathological analysis. The study subjects presented with nonulcerative and ulcerative lesions and were divided into 3 treatment groups: (1) previously untreated patients scheduled for antimycobacterial treatment, (2) patients treated with surgery alone, and (3) patients treated with surgery in combination with previous antimycobacterial treatment. Results. Of 384 suspected cases of Buruli ulcer disease, 268 were confirmed by at least 1 positive test result. The overall sensitivity of PCR (85%) was significantly higher than that of microscopic examination (57%) and culture (51%). After data were stratified by treatment group, type of lesion, and diagnostic specimen type, analysis revealed that PCR of 3-mm punch biopsy tissue specimens (obtained from previously untreated nonulcerative lesions) and of swab samples (obtained from previously untreated ulcers) had the highest diagnostic sensitivity (94% and 90%, respectively). Although duration of the disease did not significantly influence the sensitivity of any test, previous antimycobacterial treatment was significantly associated with decreased sensitivity of PCR and culture. Conclusions. Across all subgroups, PCR had the highest sensitivity. PCR assessment of 3-mm punch biopsy tissue specimens proved to be the best diagnostic tool for nonulcerative lesions, and PCR assessment of swab samples was the best diagnostic tool for ulcerative lesions. For monitoring of antimycobacterial treatment success within controlled trials, however, only culture is appropriat

    Biomarker-based diagnosis of pacemaker and implantable cardioverter defibrillator pocket infections: A prospective, multicentre, case control evaluation

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    Background: The use of cardiac implantable electronic devices (CIED) has risen steadily, yet the rate of cardiac device infections (CDI) has disproportionately increased. Amongst all cardiac device infections, the pocket infection is the most challenging diagnosis. Therefore, we aimed to improve diagnosis of such pocket infection by identifying relevant biomarkers. Methods: We enrolled 25 consecutive patients with invasively and microbiologically confirmed pocket infection. None of the patients had any confounding conditions. Pre-operative levels of 14 biomarkers were compared in infected and control (n = 50) patients. Our selected biomarkers included white blood cell count (WBC), C-reactive protein (CRP), procalcitonin (PCT), lipopolysaccharide binding protein, high-sensitivity C-reactive protein (HS-CRP), polymorphonuclear-elastase, presepsin, various interleukins, tumor necrosis factor a (TNF-a), and granulocyte macrophage colony-stimulating factor (GM-CSF). Results: Of the 25 patients with isolated pocket infection (70 13years, 76% male, 40% ICDs), none presented with leukocytosis. In contrast, they had higher serum levels of HS-CRP (p = 0.019) and PCT (p = 0.010) than control patients. Median PCT-level was 0.06 ng/mL (IQR 0.03-0.07 ng/mL) in the study group versus 0.03 ng/mL (IQR 0.02-0.04 ng/mL) in controls. An optimized PCT cut-off value of 0.05 ng/mL suggests pocket infection with a sensitivity of 60% and specificity of 82%. In addition TNF-alpha- and GM-CSF-levels were lower in the study group. Other biomarkers did not differ between groups. Conclusion: Diagnosis of isolated pocket infections requires clinical awareness, physical examination, evaluation of blood cultures and echocardiography assessment. Nevertheless, measurement of PCT- and HS-CRP-levels can aid diagnosis. However, no conclusion can be drawn from normal WBC-values

    A cross-cultural study on odor-elicited life stage-associations

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    Associative conceptualization plays an important role in how we perceive and interact with our environment. Particularly odor associations can be highly vivid and often long-lasting due to their close connection with our episodic memory and emotions. Based on the findings of a study conducted in Austria in 2017, this work was carried out to investigate odor-elicited life stage-associations (OELSA) in seven nations and to identify potential similarities and differences in conceptualizing odor impressions across these nations. A total of 1144 adults (aged 21–60) from Austria, Australia, Germany, Switzerland, Thailand, USA, and Vietnam participated in this study. Nine odors (vanilla, orange, lemon, mint, coconut, basil, rose, anise, and hay) were presented to the participants, and they were asked to answer questions about their spontaneous associations with life stages. The results indicate the existence of OELSA in all investigated nations. For example, vanilla was predominantly assigned to children in all nations, while hay was primarily assigned to elder people. While most of the investigated odors were most frequently associated with adults, some significant differences in OELSA were observed between the different nationalities. For instance, mint was more frequently associated with children by Australian participants compared to participants from all other nations, while coconut was more strongly associated with children by the Vietnamese participants compared to all other participants. The results of this study demonstrate the existence of consistent life stage-related associations elicited by certain odors across different nations and cultures and, at the same time points to differences in life stage-related association with certain odors between the nations. Since this work was not designed to identify the reasons for these differences, we can only make assumptions about the potential underlying causes for these behaviors

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    Resorptionshemmung bei Alimentärer Alkoholämie Durch Adrenalin

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    High-resolution global irradiance monitoring from photovoltaic systems

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    Reliable and regional differentiated power forecasts are required to guarantee an efficient and economic energy transition towards renewable energies. Amongst other renewable energy technologies, e.g. wind mills, photovoltaic systems are an essential component of this transition being cost-efficient and simply to install. Reliable power forecasts are however required for a grid integration of photovoltaic systems, which among other data requires high-resolution spatio-temporal global irradiance data. Hence the generation of robust reviewed global irradiance data is an essential contribution for the energy transition
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