Effect of hot strip processing during direct charging of thin slabs on the properties of cold strip of LC-steel

Direct charging of thin slabs of low carbon steel (0.05%C) was investigated by using laboratory tests on a thin-slab-casting Simulator linked with the hot deformation Simulator (Wumsi). Starting with a different initial thickness of simulated thin slabs (45 down to 25 mm) the total strain ?∑ was varied. Hot deformation schedules (with and without roughing) with different finishing temperatures T_F lead to some differences in the hot strip microstructure. Nevertheless, after cold rolling and batch annealing, a rather uniform pancake-structure and a pronounced {111}-texture were achieved in the cold strip without any significant relation to the processing routs. The measurement of final mechanical properties proved that a good deep drawability of cold strip can be achieved with direct charging of thin slabs, well comparable to that after a conventional cold charging of thick slabs.     

The band areas of proteins determined by fluorescent scanning in the commercial automated gel electrophoresis apparatus

An automated gel electrophoresis apparatus, recently available commercially, allows one to follow the band during electrophoresis in real time, and lends itself therefore to an evaluation of bandwidth as a function of migration time (the dispersion coefficient), resolution and band shape. These determinations assume the constancy of band area with migration time and at various gel concentrations. The purpose of the present study was to verify these assumptions. Representative proteins and sodium dodecyl sulfate (SDS)-proteins, either natively fluorescent or fluorescein carboxylate labeled, were found to exhibit band areas which approach constancy as a function of migration time in both agarose and polyacrylamide gel electrophoresis, provided that (i) the protein concentration under the band was low enough to obviate self-quenching of fluorescence; (ii) the separation of the protein of interest from contaminants had progressed sufficiently during the time at which band areas were measured; (iii) the baseline under the peak was sufficiently well defined. However, band areas decrease with increasing gel concentration. Protein peaks exhibited leading and trailing tails. The ratio of the combined tail area to total area appeared to be near-constant at varying migration times. However, that ratio increases with increasing gel concentration. The tail area does not appear to be an artifact of fluorometric detection since it is reproduced upon fluorimetric analysis of the protein eluted from gel slices after electrophoresis. However, it may be due to photochemical destruction under the conditions of repetitive fluorometric peak detection.     

On copulas, quasicopulas and fuzzy logic

We investigate (quasi)copulas as possible truth functions of fuzzy conjunction which is not necessarily associative and present some axiom systems for such fuzzy logics. In particular, we study an expansion of Łukasiewicz (infinite valued propositional) logic by a new connective interpreted as an arbitrary quasicopula (and also by a new connective interpreted as the residuum of the copula). Main results concern standard completeness.     

Microstructural Aspects and Optimization of Thin Slab Direct Rolling of Steels

By using a thin slab casting simulator combined with the hot deformation simulator WUMSI, laboratory tests were performed to investigate the microstructure processes and mechanical properties in the process of thin slab direct rolling (TSDR). The paper shows the possibilities to improve the initial as‐cast state of microstructure prior to hot rolling (microvoids, dendritic structure, austenite grain size, state of precipitation). The main part of the study is dedicated to the role of microalloying and sulphur for the austenite grain control and for the precipitation hardening in the final structure. On examples of selected low carbon steel grades the effect of the variation of the process parameters of hot rolling and cooling on the microstructure and mechanical properties is presented.     

Near-field optical imaging of unstained bacteria: comparison with normal atomic force and far-field optical microscopy in air and aqueous media

Simultaneous near-field scanning optical and atomic force imaging of bacteria is presented. The bacteria imaged in these studies were unstained. The near-field optical images had excellent signal-to-noise and showed excellent contrast even in these unstained specimens. The images obtained were interpreted in terms of the images that have been obtained by transmission electron microscopy and X-ray imaging. The results show that bacterial near-field optical imaging is going to be a very important tool in the arsenal of the bacteriologist both in terms of understanding the fundamental processes in the life cycle of bacteria with and without cytochemical staining and in terms of clinical diagnostic applications.     

The decrease of lasalocid residue in the edible tissues by silymarin supplementation of chicken diet

Widespread use of coccidiostats, in spite of beneficial control of protozoan infections in poultry, implies a risk of residues in edible tissues, and there is increasing interest in the development of strategies for prevention of veterinary drugs residue in food-producing animals. The aim of this study is assigned to clarify the impact of silymarin addendum in the diet on lasalocid concentration in the liver and breast muscles from the broiler. Four groups of chickens received a feed with lasalocid at levels between 75 and 200 mg kg^?1. Other four groups received a feed with lasalocid (75–200 mg kg^?1) plus silymarin. Significant differences of lasalocid concentrations between the liver and breast muscles were observed. Moreover, the chickens from the groups supplemented with silymarin shown significant decreases of lasalocid concentrations in the analysed tissues. The herbal substance did not counteract the ionophore in the treatment of coccidiosis and did not change biochemical parameters of blood. These findings suggest that silymarin might be used in chicken feeding in order to reduce the risk from lasalocid contamination of the broiler edible tissues.     

Fuzzy measures and generalized Möbius transform

Generalized Möbius transform is recalled and applied in some special cases. The relationship with the standard Möbius transform is shown. By means of the generalized Möbius transform, a general concept of k -order additivity independent of the cardinality of the underlying space is introduced. The relationship of the Choquet integral and the Lebesgue integral by means of the generalized Möbius transform is clarified. Also possibilistic Möbius transform and k -order possibility measures are introduced. Finally, some examples are given, including the characterization of de Finetti's discrete lower probabilities.     

Topographic profiling and refractive-index analysis by use of differential interference contrast with bright-field intensity and atomic force imaging

A methodology is described for phase restoration of an object function from differential interference contrast (DIC) images. The methodology involves collecting a set of DIC images in the same plane with different bias retardation between the two illuminating light components produced by a Wollaston prism. These images, together with one conventional bright-field image, allows for reduction of the phase deconvolution restoration problem from a highly complex nonlinear mathematical formulation to a set of linear equations that can be applied to resolve the phase for images with a relatively large number of pixels. Additionally, under certain conditions, an on-line atomic force imaging system that does not interfere with the standard DIC illumination modes resolves uncertainties in large topographical variations that generally lead to a basic problem in DIC imaging, i.e., phase unwrapping. Furthermore, the availability of confocal detection allows for a three-dimensional reconstruction with high accuracy of the refractive-index measurement of the object that is to be imaged. This has been applied to reconstruction of the refractive index of an arrayed waveguide in a region in which a defect in the sample is present. The results of this paper highlight the synergism of far-field microscopies integrated with scanned probe microscopies and restoration algorithms for phase reconstruction.     

Multiphase microstructure in steel bars produced by dieless drawing

In the dieless drawing technology the drawing dies are replaced by a heating device, generally by an induction coil. Bars of different cross-sections, round or even rectangular, with varying dimensions along the length can be produced. By using a cooling box in connection with the heating device this deformation process may also be employed for a thermomechanical treatment of steels. The special cooling strategy with low cooling rates at high temperatures (during ferrite formation) and higher cooling rates at lower temperatures favours the formation of multiphase microstructures (ferrite - bainite/martensite) with a low yield strength but a strong work hardening effect. The experiments were carried out on rods with a diameter of 16 mm of a plain low carbon steel (0.1%C, 0.7%Mn). The specimens were locally heated up to the maximum temperature ?_max that initiates the dieless drawing process, and subsequently cooled with different coolants. The change in yield strength and tensile strength and the corresponding change in the ratio of both could be achieved by variation of ?_max and the cooling conditions. The multiphase microstructure with desired mechanical properties was produced at a strain of about more than 0.45 within the region of ?_max ≈ 900–1000°C and a finale cooling rate of about 20 K/s.     

Effect of the finish rolling and cooling conditions on the properties of microalloyed plate steels

The processing parameters of finish rolling and cooling of three HSLA steels were varied in a wide range applying the plane strain hot compression simulation test on the hot deformation simulator (Wumsi). Evaluating the flow curves of the deformation steps, some metallurgical phenomena in austenite during hot deformation could be determined. The results of material testing after the simulation experiments exhibit a strong correlation between the finish rolling and cooling conditions and the final mechanical properties of the steels tested. As a way to increase strength, lowering finishing temperatures and/or accelerating cooling after finish rolling proved to be most effective. To improve notch toughness, on the other hand, a high total finishing strain should be applied as well as low finishing temperatures, however, above A_r3.