Nucleation and growth of the electrodeposited iron layers in the presence of an external magnetic field

The effect of an uniform magnetic field with a flux density up to 1 T and different configurations relative to the electrode surface on the electrocrystallization of Fe on polycrystalline Au(1 1 1) from acidic sulphate electrolyte has been investigated. It was found, irrespective of the applied parameters, that the deposition proceeds through successive nucleation and growth steps. The first one related to 2D growth was followed by a second nucleation and 3D diffusion controlled growth. At potential of −1500 and −1550 mV_MSE nucleation proceeds via a progressive mode, while at −1650 mV_MSE it follows an instantaneous mode. A strong influence of the parallel-to-electrode magnetic field on the nucleation processes was found for the progressive mode, which leads to the increase of the growth rate and as a consequence to retardation of the nucleation rate of the 3D step. Additionally, in this configuration at a sufficiently high magnetic flux density a third nucleation step could be observed (3D), which was found to be also affected by a magnetic field. No effect of a perpendicular-to-electrode magnetic field on the nucleation has been observed. The effects of a magnetic field on the nucleation and growth processes are discussed with respect to the magnetohydrodynamic effect (MHD) and confirmed by rotating disc electrode (RDE) experiments.     

Characteristics of carcass composition,fat metabolism and meat quality of genetically different pigs

The aim of the study was to quantify the differences in meat and fat quality and lipid metabolism of pigs with either high or medium capacity for lipid accretion. A total of 58 castrated males of the breeds German Saddle Back (SB) and German Landrace (DL) were included in the experiment. Animals were housed individually and fed twice daily semi ad libitum. Saddle Back pigs indicated a lower lean meat content (41.4% vs 52.6%) and a higher fat percentage (40.9% vs 28.2%) in comparison to DL as a result of high lipid accumulation. The larger fat content of SB was related to an increased intramuscular fat concentration of longissimus muscle. A significant correlation between intramuscular fat content and fatty acid composition was estimated in both breeds. The relative concentration of saturated fatty acids was significantly increased in SB pigs. The percentage of polyunsaturated fatty acids (8.3%) in SB muscle fat was significantly lower than in DL muscle fat (10.7%). The de novo biosynthesis of fatty acids resulted in mostly saturated fatty acids and oleic acid. The higher activities of lipogenetic enzymes in backfat of SB proved a higher lipogenetic capacity. There were no significant differences in meat quality traits of longissimus muscle between the two breeds.     

In situ analysis of three-dimensional electrolyte convection evolving during the electrodeposition of copper in magnetic gradient fields

A novel three-dimensional particle tracking velocimetry technique was used to examine the flow during electrodeposition of Cu. For the first time electrode-normal, circumferential, and radial velocities were spatially resolved during deposition in superimposed low and high magnetic gradient fields. In this way the complex interaction of magnetic field gradient force and Lorentz force induced convective effects could be measured and analyzed. Magnetic field gradient force induced electrolyte flow was detected only in high gradient magnetic fields, and it was found to be directed toward regions of gradient maxima. Since this electrode-normal flow causes enhanced transport of Cu(2+) ions from the bulk electrolyte to those regions of the working electrode where maxima of magnetic gradients are present, a structured deposit is formed during diffusion-limited electrodeposition. Lorentz force driven convection was observed during deposition in the low and the high magnetic gradient experiments. The overall fluid motion and the convection near the working electrode were determined experimentally and discussed with regard to the acting magnetic forces and numerical simulations.     

Role of vitamin A elimination or supplementation diets during postnatal development on the allergic sensitisation in mice

Vitamin A (VA) and its derivatives, the retinoids, are important factors for the development of the immune system. It has been shown in adult animals that proliferation of lymphocyte populations and antibody secretion are retinoid dependent, while little is known about the effects of retinoids during postnatal development. The aim of this study was to investigate the role of VA on allergic sensitisation during lactation and after weaning using an in vivo system for postnatal allergic sensitisation in mice. Different VA diets (basal/VA elimination/VA (as retinyl palmitate) supplemented) were fed to the dams throughout lactation and directly to the pups after weaning. Allergic sensitisation was induced with a single peritoneal ovalbumin (OVA) injection at day 28 after weaning. The phenotype of lymphocytes was analysed by flow cytometry and functional data were obtained by analysis of (IL-4/IFN-gamma) cytokine production and antibody production (OVA-specific IgG1 and IgE) in the offspring. VA/retinyl palmitate supplementation during lactation and after weaning decreased CD3+, CD4+, CD8+ and B220+ populations in splenic lymphocytes but also significantly enhanced IL-4 production and OVA-specific IgE after sensitisation. In contrast, mice fed VA-elimination diet displayed no significant alteration of lymphocyte numbers and a slightly increased IL-4 production. Our results showed that a single allergen injection during postnatal development induces allergic sensitisation whose degree is modified by the VA content of the maternal diet during lactation and the diet of the pups after weaning, indicating an important role of VA on the severity of the allergic sensitisation.     

Electrocrystallisation of metallic films under the influence of an external homogeneous magnetic field—Early stages of the layer growth

The effects of a uniform magnetic field on the early stages of Ag, Fe and CoFe alloys electrocrystallisation have been investigated. It was found for Fe and CoFe alloys, irrespective of the applied parameters, that early stages of the layer growth can be characterised by a nucleation and 3D diffusion controlled growth. The influence of the deposition parameters on the nucleation behaviour was studied on the basis of the Sharifker-Mostany (SM) model. A modification to the existing model has been proposed in order to model alloy systems. It is reported that a magnetic field superposed parallel to the electrode surface has a significant influence on the early stages of Fe and CoFe alloys growth. The growth of the nuclei is enhanced by the Lorentz-force-driven convection, while the nucleation processes remain unaffected. The hydrodynamic origin of these phenomena is confirmed by independent rotating disk electrode (RDE) investigations. Moreover, the proposed mechanism of a magnetic field influence on the 3D diffusion controlled growth is supported by a microscopic investigation of Ag deposits. It was found that Ag deposits obtained without a magnetic field superposition are characterised by a relatively large number of small 3D growth centres, whereas the deposits obtained in a field show fewer 3D centres but their size is greatly increased.     

Zur genäherten Integration von Anfangsrandwertproblemen der Wärmeleitung

Zusammenfassung Zur genäherten Integration instationärer Wärmeleitungsvorgänge wird ein Verfahren angegeben, dem eine für instationäre Probleme erweiterteGreensche Formel zugrunde liegt. Durch einen die Zeitvariable separierenden Lösungsansatz wird die Anfangsrandwertaufgabe auf ein Anfangswertproblem für zu ermittelnde Zeitfunktionen zurückgeführt, dessen Differentialsysteme durch Orthogonalisierung der Koordinatenfunktionen des Ansatzes entkoppelt werden können. Es werden für die Koordinatenfunktionen Bedingungen angegeben, unter denen die Eigenwertnäherungen dasselbe Vorzeichen erhalten wie die exakten Eigenwerte.

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Summary A method is presented, based on a generalizedGreen's formula, for the approximate integration of non-stationary problems of heat conduction. By separating the time-variable the problem is reduced to an initial value problem whose differential system can be decoupled using orthogonalisation of the coordinate functions. Conditions are given for these functions to have approximate and exact eigenvalues take on the same sign.

     

Immunoglobulin E-reactivity of wheat-allergic subjects (baker's asthma, food allergy, wheat-dependent, exercise-induced anaphylaxis) to wheat protein fractions with different solubility and digestibility

Baker's asthma, food allergy to wheat, and wheat-dependent, exercise-induced anaphylaxis (WDEIA) are different clinical forms of wheat allergy. We investigated the correlation of solubility and digestion stability of wheat allergens with the IgE-reactivity patterns of different patient groups. Three wheat protein fractions were extracted according to their solubility: salt-soluble albumins and globulins, ethanol-soluble gliadins, and glutenins soluble only after treatment with detergents and reducing reagents. Sera from subjects with history of each variant of wheat allergy were characterized by CAP FEIA and immunoblotting. There was a high degree of heterogeneity of recognized allergens between the different subject groups as well as within these groups. However, subjects with WDEIA showed similar immunoglobulin E (IgE)-reactivity patterns to gliadins and especially to a 65 kDa protein. Subjects with baker's asthma as well as the food-allergic subjects had the most intense IgE-reactivity to the albumin/globulin fraction. The latter group additionally showed IgE-reactivity to the other fractions. Divergent results of immunoblotting and CAP-FEIA demonstrated that the detection of wheat-specific IgE highly depends on the applied method, thus the diagnostic tool must be carefully chosen. Most wheat allergens were rapidly digested as analyzed by determination of IgE-reactivity on immunoblots to wheat extracts after simulation of gastric and duodenal digestion. However, ethanol-soluble gliadins were stable to gastric enzymes and exhibit low solubility in gastric and duodenal fluids. Therefore, they are likely to be important in food allergy to wheat.     

The Sensitivity of the Relative Effectiveness of Job Shop Dispatching Rules with Respect to Various Arrival Distributions

The study investigates the effects which various arrival rate distributions may have on the relative success of implementing various job shop heuristic dispatching rules. Sixteen different arrival rate distributions are tested on ten dispatching rules. General conclusions imply that the distribution with respect to shape and range of the arrival rate for incoming jobs is not a significant variable in evaluating the relative effectiveness of dispatching rules.     

A simple fluorescence-spectroscopic membrane translocation assay

We have established a combination of fluorescence-spectroscopic uptake, release, and dilution experiments as a powerful tool for studying the translocation of fluorescent compounds across lipid membranes, demonstrating this through intrinsic tryptophan fluorescence for the interaction of the cell-penetrating peptide penetratin with phospholipid membranes, for which conflicting results have been reported. We found that penetratin is not membrane-permeant under the conditions used here. To confirm this finding and to validate the approach, we also employed an established titration-calorimetric method, the results of which were in excellent agreement with a thermodynamic analysis of the fluorescence-spectroscopic experiments. Further support was provided by a comparison with published data obtained under similar conditions by using a variety of techniques. Unlike these methods, however, the new approach allows consistent and simultaneous assessment of membrane binding and transbilayer movement without depending on extrinsic labels attached to the molecule of interest or on reporter moieties inserted into the lipid membrane.