88 search hits
-
Überlegungen und Konzepte eines Produktivitätsindexes für Krankenhäuser
(2011)
-
Cornelius P. Tillmann
Ricarda B. Bouncken
- Neben dem moralischen Zwang aus dem Gebot der Menschlichkeit erleben die Dienstleister des Gesundheitsbereiches eine weitere Notwendigkeit der Sicherung hoher Qualität und Produktivität. Geöffnete Märkte, sich wandelnde Rahmenbedingungen wie ein entgeltorientiertes Vergütungssystem und sich dadurch verändernde Marktdynamiken erhöhen den Druck, unter dem Diktat sinkenden Kosten eine gleichbleibende, ja sogar steigende Qualität der medizinischen Versorgung sicherzustellen. Der Produktivität kommt dabei eine entscheidende Rolle zu. Doch nicht die Steigerung eben dieser soll Thema sein; Ziel dieser Abfassung ist vielmehr, eine Einordnung und einen Überblick über Konzepte zur Messung der Produktivität im Krankenhaus zu geben. Dabei wird auf die Herleitung zur Bildung eines Produktivitätsindexes hingearbeitet. Dieser muss sowohl weiche als auch harte Faktoren medizinischer Dienstleistungen erfassen. Das dabei erarbeitete Konzept wird diesem Anspruch insofern gerecht, als dass ein Ansatz formuliert wird, der in der Lage ist, auf theoretische Weise Qualität und Produktivität im Krankenhaus zu operationalisieren und damit mess- und vergleichbar zu machen. Denn erst, wenn Prozesse messbar sind, können sie, z.B. durch ein in- bzw. externes Benchmarking, verglichen werden. Dazu werden Kennzahlen entwickelt, die in einem entsprechenden Index zusammengefasst werden und damit in der Lage sind, umfassend über Qualität und Produktivität eines Prozesses im Krankenhaus Auskunft zu geben. Des Weiteren werden Limitationen des Modells aufgezeigt und Ideen und Ansätze, die der Weiterentwicklung des Konzeptes dienen, diskutiert.
-
Complex TERRain and ECOlogical Heterogeneity (TERRECO);WP 1-02: Spatial assessment of atmosphere-ecosystem exchanges via micrometeorological measurements, footprint modeling and mesoscale simulations ; Documentation of the Observation Period May 12th to Nov. 8th, 2010, Haean, South Korea
(2011)
-
Peng Zhao
Johannes Lüers
Johannes Olesch
Thomas Foken
- no abstract
-
Holographic Investigation of Azobenzene-Containing Low-Molecular-Weight Compounds
(2011)
-
Hubert Audorff
- In the present thesis, holographic volume and surface relief gratings in azobenzene-containing low-molecular-weight compounds are investigated to obtain a broader understanding of this new class of material. Azobenzene chromophores undergo light-induced trans-cis-trans isomerization cycles leading to a reorientation of the long axis of the chromophores. If linearly polarized light is incident on the sample, these isomerizations result in a reorientation of this axis perpendicular to the light polarization. A holographic light grating, which can be formed by the interference of two coherent laser beams, leads to the inscription of a refractive-index modulation in the material. The azobenzene-containing low-molecular-weight compounds studied in this thesis consist of different building blocks: the core unit, the azobenzene chromophores with substituents, and the spacer and the linkage group between chromophore and core unit. These components can be used in a modular-design principle to synthesize a large library of low-molecular-weight compounds. Surprisingly, some of the investigated low-molecular-weight compounds form also a liquid-crystalline phase besides the amorphous phase as evidenced by polarized microscopy. If these liquid-crystalline compounds are prepared as solid films, however, they are quenched to an amorphous state. Upon reorientation of the azobenzene chromophores by illumination with a holographic light grating, a phase transition from the amorphous to an ordered state can be induced. This phase change in the latent liquid-crystalline low-molecular-weight compounds is very interesting for applications. The latent liquid-crystalline low-molecular-weight compounds show a post-development of the refractive-index modulation after the writing process. The holographic gratings are even stable at temperatures higher than the glass transition temperature, which further proves the light-induced formation of an ordered domain. In contrast to their polymeric counterparts, molecular materials are expected to show a faster response to light because of the absence of polymer chain entanglements. Therefore, molecular glasses can be used as blending material for photo-addressable polymers to improve the photo-sensitivity of the blend as compared to the pure polymer. The influence of the core and the substituent was investigated in low-molecular-weight compounds which do not form liquid-crystalline phases. An azobenzene-containing diblock copolymer for holographic data storage consists of an inert majority block and a minority block containing the covalently bound photo-sensitive azobenzene chromophores. Blending a few weight percent of the optimized molecular glass to the diblock copolymer leads to an increase of sensitivity with increasing content of the molecular glass, mainly because the writing time to the maximum of the refractive-index modulation decreased. The increase of the sensitivity is much larger than the observed rise of the refractive-index modulation due to the higher concentration of azobenzene chromophores. It was demonstrated that the shorter writing times are not caused by thermal effects, the molecules of the molecular glass in the inert block, or by changes of the free volume or the morphology, but that they are due to the azobenzene chromophores of the molecular glass in the minority block. They reorient faster than the chromophores attached to the polymer backbone and, thereby create free volume. Additionally, they can assist the reorientation of the azobenzene chromophores bound to the polymer by cooperative effects, i.e. dipolar and steric interactions. Both effects result in shorter writing time and higher sensitivity of the system. In a blend containing two weight percent of the molecular glass, the inscribed gratings are still long-term stable and the sensitivity increases by a factor of 1.7 as compared to the pure diblock copolymer. Upon illumination of an azobenzene-containing material with a holographic light grating, besides the volume grating, also a surface relief grating can develop. Surface modulations with heights of up to 600 nm were achieved in molecular glasses. It was found that the build-up of the surface relief grating depends on the electrical susceptibility of the material at the optical frequency of the laser and the polarization of the laser beams. These experimental findings are in agreement with the gradient force model. According to this theory, the macroscopic material transport results from the forces on the polarized material in the electrical field gradient caused by the holographic light grating. For many applications it is important that the holographically produced surface relief gratings can be transferred to polymer surfaces. Replica molding can be used to easily copy the surface modulations to e.g. polycarbonate.
-
Tibet Plateau Atmosphere-Ecology-Glaciology Cluster Joint Kobresia Ecosystem Experiment: Documentation of the first Intensive Observation Period Summer 2010 in Kema, Tibet
(2011)
-
Tobias Biermann
Thomas Leipold
- no abstract
-
La sensibilisation contre le VIH/sida en Afrique de l'Ouest: Aspects linguistiques et communicatifs
(2011)
-
Martina Drescher
- Le but de cette contribution est de présenter les résultats d'une recherche sur les aspects linguistiques et interactionnels de la sensibilisation contre le VIH/sida au Burkina Faso. L'étude se base sur des enregistrements vidéo de cours de formation pour futurs pairs éducateurs. Les analyses s'inscrivent dans les approches théoriques de l'analyse de discours et de l'analyse interactionnelle. Elles se situent à deux niveaux différents et poursuivent un double objectif: Premièrement, il s'agit de reconstituer les différents discours – au sens de Foucault – présents dans les interactions. Ici, on opposera notamment le discours biomédical, de portée globale, aux discours locaux. Une analyse détaillée des dispositifs énonciatifs permettra de faire des hypothèses quant à la légitimité de ces discours et aux structures de pouvoirs sous-jacentes. Deuxièmement, on s'intéressera aux interactions en classe en focalisant sur les différents aspects de la transmission et de l'appropriation des savoirs relatifs au VIH/sida. Partant de l'idée que le transfert de savoir n'est pas un processus unilatéral, mais une négociation qui implique autant les apprenants que le formateur, un accent particulier sera mis sur les explications qui jouent un rôle clef parmi les techniques employées pour assurer le partage des savoirs.
-
Qualifizierung in der Zeitarbeit - Defizite, Rahmenbedingungen und Handlungsempfehlungen im Lichte empirischer Untersuchungen
(2011)
-
Hajo Fischer
Ricarda B. Bouncken
- Mitarbeiterqualifizierung ist schon lange ein zentrales Thema für Unternehmen. Mehr und mehr, aber immer noch zu wenig, entdeckt dies auch die Zeitarbeitsbranche. Obwohl Qualifizierung für Zeitarbeitnehmer Verleihfirmen einen deutlichen Nutzen bringt, besitzen Zeitarbeitsnehmer gegenüber Normalbeschäftigten immer noch wesentlich schlechtere Qualifizierungschancen. Dieser Beitrag zeigt anhand der Analyse bestehender empirischer Untersuchungen die Ursachen dafür auf. Dabei kristallisieren sich spezifische strukturelle Rahmenbedingungen sowie unklare Kosten-Nutzenzuordnungen in der Zeitarbeitsbranche heraus. Der Beitrag erarbeitet für Tarifpartner, Gesetzgeber und Unternehmen Möglichkeiten, diese Situation zu verbessern. Dazu werden Regelungen, finanzielle Anreize und Kooperationsansätze vorgeschlagen.
-
Modulation of Incommensurately Modulated Structures Studied by the Maximum Entropy Method
(2011)
-
Li Liang
- In this thesis, modulated properties of incommensurately modulated crystals are studied by the Maximum Entropy Method (MEM). This was done exemplarily on the compounds Rubidium tetrachlorozincate and Chromium pyrophosphate. To do so, the MEM derived (3+1)-dimensional superspace electron density was analysed to receive information on atomic positions and their modulation, and structure refinement by the method of least-squares and interpretation of the difference-Fourier maps were performed to better describe the atomic displacement parameters (ADPs) and to improve the applied structural models. All the MEM calculations are done by the computer program BayMEM. The analysis of this MEM reconstructed density map is done by the computer program EDMA. Our results suggest that the modulation of harmonic ADPs, anharmonic ADPs and its modulation form an intrinsic part of incommensurately modulated structures. We have shown that with a data set of certain resolution and satellite reflections of higher order, the inclusion of modulation of harmonic ADPs, the anharmonic ADPs and the modulation of anharmonic ADPs can significantly improve the fit of the structure model to the diffraction data. Such model then better represents the true nature of the structure under investigation.
-
Pedogenic carbonates in loess formation rates, formation conditions and source apportionment assessed by isotopes and molecular proxies
(2011)
-
Martina Gocke
- Interest in secondary (pedogenic) carbonates as an archive for paleoclimatic reconstructions in arid and semiarid regions has increased during recent decades. Their carbon (C) isotope composition represents the conditions prevailing during their formation because they are formed by precipitation of Ca2+ from soil solution with dissolved CO2 from soil air originating from root and rhizomicrobial respiration. Thus, pedogenic carbonates are an important tool for estimation of age of pedogenesis and for reconstruction of the local paleovegetation. Potential reequilibration of pedogenic carbonates with younger soil CO2 can entail loss of chronological and paleoenvironmental information. Although methodological resolution of these studies depends on the time scale of pedogenic carbonate formation and recrystallization, its rates and periods remain unknown. The first objective therefore was the first-time assessment of the time frame of pedogenic CaCO3 formation and recrystallization under controlled conditions. The other aim was to reveal the potential of rhizoliths, a special form of pedogenic carbonates (calcified roots), from a loess-paleosol sequence for paleoenvironmental studies. In loess as a common soil parent material, initial CaCO3 recrystallization rates were successfully determined with the 14C isotopic exchange approach by exposing loess to artificially labeled 14CO2 and subsequent quantification of 14C incorporated in secondary (recrystallized) CaCO3. Within the range of natural soil CO2 concentrations, recrystallization rates increased strongly with CO2 concentration. In further studies, loess was exposed to 14CO2 respired by roots and rhizomicrobial organisms of plants labeled in 14CO2 atmosphere, to estimate the effects of several factors (root vicinity, temperature, accumulation depth) on the recrystallization rate. Rates from planted loess were two orders of magnitude higher than those from unplanted loess, mostly in the range of 10-5 day-1. Significantly higher CaCO3 recrystallization rates in rhizosphere than in loess distant from roots were attributed to three factors: high CO2 concentration from root and rhizomicrobial respiration, low pH caused by release of CO2 and root exudates, and high Ca2+ and HCO3- concentration caused by water uptake by roots. Considerable influence of the latter was demonstrated by low CaCO3 recrystallization rates at low temperatures and vice versa, reflecting the increasing transpirational pull with increasing temperatures. Assuming repeated recrystallization of both primary and secondary CaCO3, extrapolation of initial CaCO3 recrystallization rates showed that at least 102 – 103 years are necessary for complete recrystallization of CaCO3 in ‘root-free’ loess by formation of secondary CaCO3, depending on length of the growing season. Increasing temperature promoted CaCO3 recrystallization rates, but the contrast was compensated for recrystallization periods because of the negative effect of increasing temperature on length of the growing season. In contrast, pedogenic carbonates can form much faster close to roots (101 – 102 years) because of mass flow to the roots leading to rhizolith formation. As a consequence of this wide temporal spectrum of pedogenic carbonate formation, variable methodological resolution has to be considered in paleoenvironmental studies based on stable isotope composition of pedogenic carbonates, depending on climatic factors and formation of carbonate concretions. Rhizoliths, formed by encrustation of roots with secondary CaCO3, yield high potential for paleoenvironmental studies. At the late Pleistocene loess-paleosol sequence of Nussloch, SW Germany, rhizolith CaCO3 was completely secondary and not contaminated by postsegregational alteration. Radiocarbon dating of one rhizolith sample reinforced the assumption of potential postsedimentary formation of rhizoliths. In the investigated profile, stable C isotope composition indicated C3 source vegetation for organic matter (OM) of both loess and rhizoliths, but lipid molecular proxies revealed grass biomass as origin of loess OM, and shrub or tree roots as source of rhizoliths. Moreover, OM in loess adjacent to rhizoliths was considerably contaminated by rhizomicrobial and root remains at least up to a distance of 5 cm. Alteration of loess OM and its isotope composition by postsedimentary penetration of deep-rooting plants might entail uncertainties for paleoenvironmental studies based on loess OM. In summary, the important role of vegetation on pedogenic CaCO3 formation and recrystallization was shown under controlled and field conditions. Plant roots and associated microorganisms have direct influence on these processes, while further factors of pedogenesis like climate exert an indirect effect, but on the long term probably are of greater importance than effects on the rhizosphere scale.
