Die Musikkritik - ein schulpädagogisches Aufgabenfeld? Bemerkungen zum Umgang mit Musikkritik im Unterricht der Sekundarstufe I und II

Im Bedingungsgefüge der musikalischen Produktion, Interpretation, Rezeption (bezogen sowohl auf das musikalische Ereignis selbst als auch auf die Aufnahme der musikkritischen Reflexion) und Distribution wirkt die Musikkritik regulierend und stimulierend auf den Kunstprozeß in seiner vielschichtigen sozialen Bestimmung und personellen Bestimmtheit. Die sich hieraus ergebende Wirkungsabsicht der Musikkritik bezüglich einer spezifischen Art der Leser- bzw. Hörerbeeinflussung und -formierung wird von verschiedenen Autoren musikkritischer Darstellungen berechtigt als pädagogische Seite des musikkritischen Schrifttums angesehen. Diesen allgemeinen pädagogischen Ansatzpunkt gilt es weiterzuführen, indem von der Überlegung ausgegangen wird, das musikalische Schrifttum auch für eine beziehungsreiche und effektive Gestaltung von Lernprozessen im Musikunterricht und in der außerunterrichtlichen musikerzieherischen Arbeit an allgemein bildenden Schulen nutzen. (DIPF/Orig.

Microfluidically prepared sensor particles for determination of chloride by fluorescence quenching of matrix-embedded lucigenin

Polyacrylamide sensor particles have been synthesized by using a microfluidic arrangement for generation of microdroplets containing a reaction mixture for forming gel microparticles. The droplets are formed in an inert carrier liquid immiscible with the reaction mixture based on aqueous solutions. Gel particles are formed in situ by photochemical initiation of polymerization inside droplets using an UV-sensitive photoinitiator. In result, water-swellable spheres with submillimetre size are obtained. Those spheres were loaded with N,N′-dimethyl-9,9′-biacridinium dinitrate (lucigenin) as ion selective fluorescence probe for chloride. The particles can be dried, stored and re-swollen. Upon exposure of dried particles to sodium chloride solutions they showed dynamic fluorescence quenching obeying the linear plot of Stern–Volmer-equation between 0 and 130 mM Cl−. Thus, chloride concentrations up to 50 mM could be measured with appropriate accuracy. The particles allow a fast optical determination of chloride in tiny analyte volumes down to below ten microliters

Micro flow photochemical synthesis of ca‐sensitive fluorescent sensor particles

Fluorescence probes have widely been used for detecting and imaging Ca 2+ ‐enriched parts of cells but more rarely for quantitative determination of concentrations. In this study we show how this can be achieved by a novel approach using hydrogel particles. In a microfluidic co‐flow arrangement spherical droplets were generated from an aqueous solution of acrylamide, N,N '‐methylenebisacrylamide crosslinker and photoinitiator and subsequently photo‐cured in situ yielding gel particles in a sub millimeter range. These particles were separated, dried under reduced pressure and re‐swollen in water containing Rhod‐5N tri potassium salt as calcium ion selective fluorescence probe. After that the particles were dried again and stored for further investigations. Upon exposure of dried particles to calcium chloride solutions they swell and take up Ca 2+ ‐ions forming a strong fluorescing complex with Rhod‐5N. Thus, fluorescence intensity increases with calcium ion concentration. Up to ca. 0.50 mM the enhancement effect is strong and then becomes considerably weaker. The intensity‐concentration‐dependence is well described by an equation derived from the equilibrium of the formation of a 1:1 Ca 2+ :Rhod‐5N complex. The particles allow for a fast optical determination of Ca 2+ ‐concentrations up to 0.50 mM in analyte volumes down to below 10 μL

Comparison of a standard CO2 pressure pneumoperitoneum insufflator versus AirSeal™: study protocol of a randomized controlled trial

BACKGROUND: AirSeal™ is a novel class of valve-free insufflation system that enables a stable pneumoperitoneum with continuous smoke evacuation and carbon dioxide (CO(2)) recirculation during laparoscopic surgery. Comparison data to standard CO(2) pressure pneumoperitoneum insufflators is scarce. The aim of this study is to evaluate the potential advantages of AirSeal™ compared to a standard CO(2) insufflator. METHODS/DESIGN: This is a single center randomized controlled trial comparing elective laparoscopic cholecystectomy, colorectal surgery and hernia repair with AirSeal™ (group A) versus a standard CO(2) pressure insufflator (group S). Patients are randomized using a web-based central randomization and registration system. Primary outcome measures will be operative time and level of postoperative shoulder pain by using the visual analog score (VAS). Secondary outcomes include the evaluation of immunological values through blood tests, anesthesiological parameters, surgical side effects and length of hospital stay. Taking into account an expected dropout rate of 5%, the total number of patients is 182 (n = 91 per group). All tests will be two-sided with a confidence level of 95% (P <0.05). DISCUSSION: The duration of an operation is an important factor in reducing the patient’s exposure to CO(2) pneumoperitoneum and its adverse consequences. This trial will help to evaluate if the announced advantages of AirSeal™, such as clear sight of the operative site and an exceptionally stable working environment, will facilitate the course of selected procedures and influence operation time and patients clinical outcome. TRIAL REGISTRATION: ClinicalTrials.gov NCT01740011, registered 23 November 2012

Textured and hierarchically constructed polymer micro- and nanoparticles

Microfluidic techniques allow for the tailored construction of specific microparticles, which are becoming increasingly interesting and relevant. Here, using a microfluidic hole-plate-device and thermal-initiated free radical polymerization, submicrometer polymer particles with a highly textured surface were synthesized. Two types of monomers were applied: (1) methylmethacrylate (MMA) combined with crosslinkers and (2) divinylbenzene (DVB). Surface texture and morphology can be influenced by a series of parameters such as the monomer–crosslinker–solvent composition, surfactants, and additives. Generally, the most structured surfaces with the simultaneously most uniform particles were obtained in the DVB–toluene–nonionic-tensides system. In a second approach, poly-MMA (PMMA) particles were used to build aggregates with bigger polymer particles. For this purpose, tripropyleneglycolediacrylate (TPGDA) particles were synthesized in a microfluidic co-flow arrangement and polymerized by light- irradiation. Then, PMMA particles were assembled at their surface. In a third step, these composites were dispersed in an aqueous acrylamide–methylenebisacrylamide solution, which again was run through a co-flow-device and photopolymerized. As such, entities consisting of particles of three different size ranges—typically 0.7/30/600 µm—were obtained. The particles synthesized by both approaches are potentially suitable for loading with or incorporation of analytic probes or catalysts such as dyes or metals

Geometry and Distortion Prediction of Multiple Layers for Wire Arc Additive Manufacturing with Artificial Neural Networks

Wire arc additive manufacturing (WAAM) is a direct energy deposition (DED) process with high deposition rates, but deformation and distortion can occur due to the high energy input and resulting strains. Despite great efforts, the prediction of distortion and resulting geometry in additive manufacturing processes using WAAM remains challenging. In this work, an artificial neural network (ANN) is established to predict welding distortion and geometric accuracy for multilayer WAAM structures. For demonstration purposes, the ANN creation process is presented on a smaller scale for multilayer beads on plate welds on a thin substrate sheet. Multiple concepts for the creation of ANNs and the handling of outliers are developed, implemented, and compared. Good results have been achieved by applying an enhanced ANN using deformation and geometry from the previously deposited layer. With further adaptions to this method, a prediction of additive welded structures, geometries, and shapes in defined segments is conceivable, which would enable a multitude of applications for ANNs in the WAAM-Process, especially for applications closer to industrial use cases. It would be feasible to use them as preparatory measures for multi-segmented structures as well as an application during the welding process to continuously adapt parameters for a higher resulting component quality

Robust phase unwrapping based on non-coprime fringe pattern periods for deflectometry measurements

Phase-measuring deflectometry is a technique for non-contact inspection of reflective surfaces. A camera setup captures the reflection of a sine-modulated fringe pattern shifted across a screen; the location-dependent measured phase effectively encodes the screen coordinates. As the used fringe patterns are much narrower than the screen dimension, the resulting phase maps are wrapped. The number-theoretical solution uses the Chinese remainder theorem to calculate an unwrapped phase map from repeated measurements with coprime fringe widths. The technique is highly susceptible to phase noise, i.e. small deviations of the measured phase values generally lead to unwrapped phase values with large errors. We propose a modification and show how non-coprime period widths make phase unwrapping robust against phase noise. Measurements with two non-coprime fringe period widths introduce the opportunity to discriminate between “legal” measured phase value pairs, that potentially originate from noise-free measurements, and “illegal” phase value pairs, that necessarily result from noise-affected measurements. Arranged as a matrix, the legal measurements lie on distinct diagonals. This insight not only allows to determine the legality of a measurement, but also to provide a correction by looking for the closest legal matrix entry. We present an experimental comparison of the resulting phase maps with reference phase maps. The presented results include descriptive statistics on the average rate of illegal phase measurements as well as on the deviation from the reference. The measured mean absolute deviation decreases from 1.99 pixels before correction to 0.21 pixels after correction, with a remaining maximum absolute deviation of 0.91 pixels

The effects of pattern screen surface deformation on deflectometric measurements - A simulation study

Phase-measuring deflectometry (PMD) is an optical inspection technique for full-field topography measurements of reflective sample surfaces. The measurement principle relies on the analysis of specific patterns, reflected at the sample surface. Evaluation algorithms often model the respective pattern screen as a planar light source. However, the 32\u27\u27 pattern screen in our inspection setup exhibits a central bulge of its surface of about 2–3 mm. This paper presents a simulation framework for PMD to evaluate the effects of a deformed screen surface. The idea is to simulate image data acquired with screen surface deformations and to examine the effects on the PMD evaluation results. The simulated setup consists of a 32\u27\u27 pattern screen with an adjustable central bulge height of 0–3 mm and two cameras with a field of view (FOV) of approximately 225 mm by 172 mm on the sample surface. A first experiment examines the reconstruction errors for a planar sample surface if the reconstruction algorithm uses perfect calibration data (i.e. the same parameters used for the simulated image acquisition). The reconstructed surfaces exhibit a tilt with a maximum height difference of 174 μm across the FOV. A second experiment repeats the reconstruction process of the same sample surface, using camera parameters determined in a simulated calibration process. The resulting surfaces possess irregular, wave-like errors with amplitudes of up to 9 μm in the FOV. The presented simulation results reveal the accuracy limits if a deformation model of the pattern screen is not explicitly included in the reconstruction process