221 research outputs found
Stakeholderpartizipation in der Schule: ein Beitrag zu einer Organisationstheorie der Schule aus mikropolitischer Perspektive
"Partizipation ist Ausdruck von Schulkultur und prägt diese zugleich. Dieses Buch geht der Frage nach, inwieweit Stakeholder, die in und von der Organisation Schule betroffen sind, an dieser partizipieren. Vor dem Hintergrund einer mikropolitischen Analysefolie wird die Fragestellung anhand einer qualitativen Einzelfallstudie untersucht, die an einer berufsbildenden mittleren bzw. höheren Schule in Österreich durchgeführt wurde. Diese Arbeit stellt einen Beitrag zur Diskussion zum Umgang mit pädagogischen Innovationen in Schulen dar und schließt mit einem Ansatz einer Organisationstheorie für Schulen, der die Besonderheiten und Spezifika von Schulen - bspw. pädagogischer und gesellschaftlicher Auftrag - berücksichtigt. Der diskutierte Ansatz kann als Ausgangspunkt dienen, um strukturelle Änderungen und deren Auswirkungen auf schulische Handlungen zu analysieren und zu thematisieren." (Autorenreferat
A novel synthesis of the N-13 labeled atmospheric trace gas peroxynitric acid
Radioactively labeled trace gases have been successfully used to study heterogeneous chemistry of atmospheric relevance. Here we present anew synthesis of gas-phase peroxynitric acid labeled with 13N (H13NO4) to study the interaction of HNO4 with ice and snow surfaces. Ayield of about 30% for HNO4 was determined. The main by-products were HNO3 and HNO2. Exposure of an ice packed bed flow tube to these species revealed that the interaction with the surface scale in the order HNO3ߙ>ߙHNO4ߙ=ߙHNO2ߙ>ߙNO
Record-light weight c-Si modules based on the small unit compound approach : mechanical load tests and general results
The “small unit compound” (SUC) concept allows the preparation of very light weight c-Si solar laminates utilizing thin glass or plastic materials. A main difference to the common module type is the replacement of the frame at the laminates fringe by a lattice-like structure at the rear or at the rear and front side. Due to the small distances between the mechanical supporting elements which prevent the dishing of the laminate, the stiffness of the laminate itself can be reduced to a minimum. This enables the use of thin glass or alternative materials such as polymer foils. In this paper we present results of mechanical tests with such modules and discuss general results concerning the module lay-out. The paper has a focus on glass/glass and glass/backsheet laminates with glass thicknesses of 0.8, 1.1, 1.6 and 2 mm. A 60 cell glass/backsheet module 0.8 mm front glass with a weight of as low as 6.3 kg (without junction box and cables) has been fabricated. According to our knowledge this is the lowest weight for 60-cell c-Si modules with front glass ever reported. First hail resistance tests show that these modules may surpass the IEC 61215 norm. Only slightly lower weights are possible if alternative materials are used instead of glass for the front side cover
Production and use of 13N labeled N2O5 to determine gas-aerosol interaction kinetics
Dinitrogen pentoxide has aroused significant interest in atmospheric chemistry because of its importance in the night time chemistry of nitrogen oxides to influence the tropospheric oxidation capacity. We have used an established method of 13N production to synthesize 13N labeled N2O5 for the first time in order to study N2O5 uptake kinetics on aerosol particles. 13N is produced via the 16O(p, α)13N reaction in a gas target attached to the IP2 endstation of the Injector 2 cyclotron at PSI. The 13NO produced in the gas target is transported to a laboratory where it is mixed, under dry conditions, with non-labeled NO and O3 in a gas reactor, giving 13NNO5. The N2O5 thus produced is fed into an aerosol flow tube together with a humidified aerosol gas flow. The gaseous species present in the resulting gas flow are selectively separated via a narrow parallel plate diffusion denuder system, while aerosol particles can be trapped on a particle filter placed at the end of the denuder system. The activity of the 13N labeled species trapped on the denuder plates and in the particle filter can be monitored via scintillation counters. A system for the routine online production of 13N labeled N2O5 has been assembled and used to assess the conformity of the results by kinetic modeling of gas phase N2O5 chemistry, showing good agreement. A few exemplary experiments of uptake of labelled N2O5 to ammonium sulfate and citric acid particles are presented that are in good agreement with results obtained with other methods reported in the literatur
Estimating the uptake of traffic-derived NO2 from 15N abundance in Norway spruce needles
The 15N ratio of nitrogen oxides (NOx) emitted from vehicles, measured in the air adjacent to a highway in the Swiss Middle Land, was very high [δ15N(NO2) = +5.7‰]. This high 15N abundance was used to estimate long-term NO2 dry deposition into a forest ecosystem by measuring δ15N in the needles and the soil of potted and autochthonous spruce trees [Picea abies (L.) Karst] exposed to NO2 in a transect orthogonal to the highway. δ15N in the current-year needles of potted trees was 2.0‰ higher than that of the control after 4 months of exposure close to the highway, suggesting a 25% contribution to the N-nutrition of these needles. Needle fall into the pots was prevented by grids placed above the soil, while the continuous decomposition of needle litter below the autochthonous trees over previous years has increased δ15N values in the soil, resulting in parallel gradients of δ15N in soil and needles with distance from the highway. Estimates of NO2 uptake into needles obtained from the δ15N data were significantly correlated with the inputs calculated with a shoot gas exchange model based on a parameterisation widely used in deposition modelling. Therefore, we provide an indication of estimated N inputs to forest ecosystems via dry deposition of NO2 at the receptor level under field conditions
Bactericidal Activity of N-Chlorotaurine against Biofilm-Forming Bacteria Grown on Metal Disks
Many orthopedic surgeons consider surgical irrigation and debridement with prosthesis retention as a treatment option for postoperative infections. Usually, saline solution with no added antimicrobial agent is used for irrigation. We investigated the activity of N-chlorotaurine (NCT) against various biofilm-forming bacteria in vitro and thereby gained significant information on its usability as a soluble and well-tolerated active chlorine compound in orthopedic surgery. Biofilms of Staphylococcus aureus were grown on metal alloy disks and in polystyrene dishes for 48 h. Subsequently, they were incubated for 15 min to 7 h in buffered solutions containing therapeutically applicable concentrations of NCT (1%, 0.5%, and 0.1%; 5.5 to 55 mM) at 37°C. NCT inactivated the biofilm in a time- and dose-dependent manner. Scanning electron microscopy revealed disturbance of the biofilm architecture by rupture of the extracellular matrix. Assays with reduction of carboxanilide (XTT) showed inhibition of the metabolism of the bacteria in biofilms. Quantitative cultures confirmed killing of S. aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa biofilms on metal alloy disks by NCT. Clinical isolates were slightly more resistant than ATCC type strains, but counts of CFU were reduced at least 10-fold by 1% NCT within 15 min in all cases. NCT showed microbicidal activity against various bacterial strains in biofilms. Whether this can be transferred to the clinical situation should be the aim of future studies
A psychoeducational intervention reduces the need for anesthesia during radiotherapy for young childhood cancer patients
<p>Abstract</p> <p>Background</p> <p>Radiotherapy (RT) has become an important treatment modality in pediatric oncology, but its delivery to young children with cancer is challenging and general anesthesia is often needed.</p> <p>Methods</p> <p>To evaluate whether a psychoeducational intervention might reduce the need for anesthesia, 223 consecutive pediatric cancer patients receiving 4141 RT fractions during 244 RT courses between February 1989 and January 2006 were studied. Whereas in 154 RT courses corresponding with 2580 RT fractions patients received no psychoeducational intervention (group A), 90 RT courses respectively 1561 RT fractions were accomplished by using psychoeducational intervention (group B). This tailored psychoeducational intervention in group B included a play program and interactive support by a trained nurse according to age to get familiar with staff, equipment and procedure of radiotherapy.</p> <p>Results</p> <p>Group A did not differ significantly from group B in age at RT, gender, diagnosis, localization of RT and positioning during RT. Whereas 33 (21.4%) patients in group A got anesthesia, only 8 (8.9%) patients in group B needed anesthesia. The median age of cooperating patients without anesthesia decreased from 3.2 to 2.7 years. In both uni- and multivariate analyses the psychoeducational intervention significantly and independently reduced the need for anesthesia.</p> <p>Conclusion</p> <p>We conclude that a specifically tailored psychoeducational intervention is able to reduce the need for anesthesia in children undergoing RT for cancer. This results in lower costs and increased cooperation during RT.</p
Photochemical formation of nitrite/nitrous acid (HONO) upon irradiation of nitrophenols in aqueous solution and in viscous secondary organic aerosol proxy
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Evaluated kinetic and photochemical data for atmospheric chemistry: Volume VII-Criegee intermediates
This article, the seventh in the series, presents kinetic and photochemical data sheets evaluated by the IUPAC Task Group on Atmospheric Chemical Kinetic Data Evaluation. It covers an extension of the gas-phase and photochemical reactions related to Criegee intermediates previously published in Atmospheric Chemistry and Physics (ACP) in 2006 and implemented on the IUPAC website up to 2020. The article consists of an introduction, description of laboratory measurements, a discussion of rate coefficients for reactions of O3 with alkenes producing Criegee intermediates, rate coefficients of unimolecular and bimolecular reactions and photochemical data for reactions of Criegee intermediates, and an overview of the atmospheric chemistry of Criegee intermediates. Summary tables of the recommended kinetic and mechanistic parameters for the evaluated reactions are provided. Data sheets summarizing information upon which the recommendations are based are given in two files, provided as a Supplement to this article. © Author(s) 2020
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