Microstructure and Compression Strength of Novel TRIP‐Steel/Mg‐PSZ Composites

Novel composites on basis of austenitic stainless TRIP‐steel as matrix with reinforcements of Mg‐PSZ are presented. Compact rods were produced by cold isostatic pressing and sintering, square honeycomb samples by the ceramic extrusion technique. The samples are characterized by optical and scanning electron microscopy before and after deformation, showing the microstructure and the deformation‐ induced martensite formation. The mechanical properties of samples with 5 vol% zirconia are superior compared to zirconia‐free samples and composites with higher zirconia contents in terms of bending and compression tests. The honeycomb samples exhibit extraordinary high specific energy absorption in compression.     

Beckmann's Studio Computers Specified for Early Computer Art

When the pioneers of computer art started to produce their works by programming mainframes, using plotters for output, the Austrian sculptor Otto Beckmann took a different path. He used a special computer constructed by his son Oskar Beckmann. This article describes the technical context of early computer art, Beckmann's interdisciplinary team ars intermedia, and the development of nonconventional studio computers.     

Effects of sprayer configuration on efficacy for the control of scab on crabapple using electron beam analysis

Foliar diseases like apple scab result in significant economic losses to growers each year. Assessment in past studies involved only macroscopic disease ratings. More complete knowledge of the fate and behavior of fungicide has been needed to reduce pesticide use with less off‐target contamination. Field studies were conducted in a production nursery for over 4 years. A moderately susceptible cultivar of ornamental crabapple, Malus spp. cv “Candied Apple”, was sprayed with a fungicide using two sprayer/nozzle configurations. The fungicide used in this study was Mankocide, combination of Cu(OH)₂ and mancozeb that permitted electron beam analysis (EBA) identification based on the presence of Cu, MN and Zn in the molecule and formulation. EBA was conducted using a cold field emission scanning electron microscopy and energy dispersive x‐ray microanalyzer. Fresh leaf samples were placed on sticky stubs after each fungicide treatment. The presence or absence of fungal conidia and fungicide residue were measured. EBA permitted direct visualization and identification of the pathogens, morphologically, and chemical characterization of fungicide present. EBA was useful to quantify disease control related to fungicide coverage, sprayer configuration and treatment efficacy. SCANNING 31: 24–27, 2009. Published 2009 by Wiley Periodicals, Inc.     

Computational algorithms for networks of queues with rejection blocking

Summary Open, closed and mixed queueing networks with reversible routing, multiple job classes and rejection blocking are investigated. In rejection blocking networks blocking event occurs when upon completion of its service of a particular station's server, a job attempts to proceed to its next station. If, at that moment, its destination station is full, the job is rejected. The job goes back to the server of the source station and immediately receives a new service. This is repeated until the next station releases a job and a place becomes available. In the model jobs may change their class membership and general service time distributions depending on the job class are allowed. Two station types are considered: Either the scheduling discipline is symmetric, in which case the service time distributions are allowed to be general and dependent on the job class or the service time distributions at a station are all identical exponential distributions, in which case more general scheduling disciplines are allowed. An exact product form solution for equilibrium state probabilities is presented. Using the exact product form solution of the equilibrium state distribution, algorithms for computation of performance measures, such as mean number of jobs and throughputs, are derived. The complexity of the algorithms is discussed.     

Use of the finite elements method for modelling the dynamic load impact on hydraulic leg equipped with gas accumulator

Procedures of preparation of numerical analysis, consisting in a simulation of cooperation of three different media: steel, liquid and gas undergoes dynamic load were discussed. Modelling of the initial static load of the mechanical system was presented. By using the MSC. Software products the following exemplary computer simulations were made: dynamic load impact on the hydraulic leg as well as effectiveness of the hydraulic leg protection against overload with help of gas accumulator.     

Diffusion of ammonia in silicalite studied by QENS and PFG NMR

Ammonia diffusivities in silicalite have been studied by quasi-elastic neutron scattering (QENS) and pulsed-field gradient (PFG) NMR for temperatures between 200 and 500 K and loadings from 1.5 up to 4.3 molecules per unit cell. The diffusion coefficients obtained by both techniques increase with increasing ammonia concentration. The QENS diffusivities refer to only a certain fraction of molecules, because during the time scale of the measurement the other part of molecules is essentially immobile, in interaction with silanol groups. During the much larger time scale of the PFG NMR experiment, ammonia molecules assume both states of mobility, leading to an average diffusivity which is smaller than the diffusivity of the mobile molecules recorded by QENS. The difference between the diffusivities derived from both techniques decreases when the proportion of immobile molecules is taken into account. The residence time of ammonia in interaction with silanol groups is about two orders of magnitude longer than with oxygen atoms.     

Bücherschau

Ohne Zusammenfassung VDI     

Composition and quality attributes of conventionally and organically farmed Pangasius fillets (Pangasius hypophthalmus) on the German market

A range of conventionally and organically farmed Pangasius or sutchi catfish fillets available on the German market were analysed to compare both composition and quality. Differentiation of Pangasius hypophthalmus from Pangasius bocourti was achieved by RFLP-SSCP analysis. The protein content of conventionally farmed fillets ranged between 13.3 and 15.7%, whereas organically produced fillets had significantly higher protein contents of between 17.0 and 17.4%. No difference in the fat content between farming methods was observed, which varied between 1.4 and 3.2%. Polyunsaturated fatty acids represented about 24% of the total fatty acids with a high level of linoleic acid. The comparison of the proximate composition indicated that water was added to most of the conventionally farmed products, in different amounts, as well as water-binding capacity enhancing additives. Differential scanning calorimetry was used to demonstrate the presence of polyphosphate on muscle proteins. Differences in texture, water-binding capacity and colour are discussed.