Modelling water cooling of steel strip during hot rolling

Several tests of water cooling of steel samples are presented in the paper. The water spray and quenching conditions are considered. The temperature variations during the tests are monitored using the thermocouples embedded in the side of the samples. The experimental time – temperature profiles are compared with the results of calculations based on the finite element model. Comparison of the theoretical and experimental results allowed to suggest heat transfer coefficients of 10000 W/m²K for water in quenching, 6000 W/m²K for the top surface during water spray cooling and 4000 W/m²K for the bottom surface during water spray cooling.     

Nanoscale mechanical properties of polymers irradiated by UV

The application of depth sensing nanoindentation to determine mechanical properties of three different polymers is described in this work using three different techniques to calibrate the measurement system. The nano-hardness and the elastic indentation modulus of polyvinyl chloride, polyethylene oxide and polyacrylic acid were inferred from nanomechanical tests, and the influence of ultraviolet irradiation on the mechanical properties of measured polymers is studied. A multicycling test—a sequence of several loading and unloading procedures—allowed the measurement of changes in the sample viscoelasticity. The nano-hardness of the polymers is shown to increase with radiation dose while the viscoelasticity decreases.     

Application of monodispersive anion exchangers in sorption and separation of y3+ from Nd3+ and Sm3+ complexes with dcta

Rare earth complexes with trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (DCTA) of the Ln(dcta)- ype exhibited an unusual sequence of affinity on the polystyrene anion exchangers: pm3 >Nd3 >Sm3 >pr3 >Ce3 >Eu3 >Gd3 >La3 >Sc3 >Tb3 >Dy3 >Ho3 >y3 >Er3 >Tm3 >yb3 >Lu3 [1]. Taking into account the position of Y3 , Sm3 , and Nd3 in this affinity series, for the monodispersive polystyrene anion exchangers, Lewafit MonoPlus M 500, Lewatit MonoPlus M 600, Lewatit MonoPlus MP 500, Lewatit MonoPlus MP 64,and for the heterodispersive anion exchanger, Lewatit MP 62, the weight (Dg,) and bed (Dv) distribution coefficients of these complexes and working ion exchange capacities (Cw) were determined. Based on these values, purifications of Y3 from Nd3 and y3 from Sm3 in the macro-micro component system on these anion exchangers were studied. The application potential of this method was highlighted for the separation of yz3 in the presence of Nd3 and Sm3 . With 1 L of monodispersive and strongly basic polystyrene gel anion exchanger Lewatit MonoPlus M 500 in the acetate form, it is possible to obtain approximately 79 g Y2O3 purified from Nd2O3 and 70 g Y2O3 purified from Sm2O3 in the same process condition.     

Anomalous behavior of near fields calculated by the method of moments

The method of moments can be used to find solutionsJof the equationX(J) = lambda R(J), whereRandXare the real and imaginary parts (respectively) of theZ(impedance) operator of a perfectly conducting body. These solutions, called the characteristic currents, are characterized by an important near-field feature-the resulting free-space electric fields tangential to the body are constant in phase over the entire body. Although the method of moments is often used to solve electromagnetic problems where the far radiation fields of the solution currents are of interest, general moment-method theory indicates that the technique should also yield current solutions exhibiting accurate near-field behavior as the dimension of the solution space is increased. The near-field phase characteristics of resonant thin-wire characteristic current distribution, as calculated by several familiar moment-methods schemes, are presented. The ensuing discussion reveals several anomalies concerning the near-field behavior of the fields resulting from these currents. These anomalies are then discussed in light of the basic rudiments of the method of moments.     

Antioxidative and Bactericidal Properties of Phenolic Compounds in Rapeseeds

Antioxidative and bactericidal properties were investigated in isolated and fractionated phenolic compounds of rapeseeds. Among the investigated groups of compounds (phenolic acids, sinapine and the products of its hydrolysis) phenolic acids, and especially sinapic acid, were found to be the most active. Due to valuable properties of these compounds they can be considered to be applied for food and fodder preserving.     

Synthesis and characterization of poly[2-(10-undecenoyloxy)ethyl methacrylate]

Summary By Schotten-Baumann's esterification of poly(2-hydroxyethyl methacrylate) with 10-undecenoyl chloride a new multimonomer - poly[2-(10-undecenoyloxy)ethyl methacrylate] was prepared. Based on the results of elemental analysis, FTIR, ¹H-NMR and ¹³C-NMR spectra, the structure of the multimonomer was proposed. The thermal properties of the multimonomer were studied by DSC and TG. The rate of disappearance of double bonds in the multimonomer during UV irradiation was examined in the solid state to obtain a crosslinked product. Received: 17 September 2001/Revised version: 5 February 2002/ Accepted: 7 March 2002     

Comparative study of the protein patterns of some rapeseed (Brassica napus L.) varieties by means of polyacrylamide gel electrophoresis and high-performance liquid chromatography

Seven rapeseed varieties were characterized by investigation of the patterns of buffer soluble proteins using polyacrylamide gel electrophoresis and high-performance liquid chromatography (size-exclusion and cation-exchange chromatography). Most pronounced differences were found in proteins not belonging to 12 S and 2 S storage proteins having presumably metabolic functions. Quantitative variations dominate within the low molecular mass 2 S storage proteins.     

Sialic Acid—Modified Nanoparticles—New Approaches in the Glioma Management—Perspective Review

The cell surface is covered by a dense and complex network of glycans attached to the membrane proteins and lipids. In gliomas, the aberrant sialylation, as the final stage of glycosylation, is an important regulatory mechanism of malignant cell behavior and correlates with worse prognosis. Better understanding of the role of sialylation in cellular and molecular processes opens a new way in the development of therapeutic tools for human brain tumors. According to the recent clinical observation, the cellular heterogeneity, activity of brain cancer stem cells (BCSCs), immune evasion, and function of the blood–brain barrier (BBB) are attractive targets for new therapeutic strategies. In this review, we summarize the importance of sialic acid-modified nanoparticles in brain tumor progression.     

Application of √t-type, logarithmic and half-time methods in desorptive measurements of diffusivity in narrow humidity ranges

This paper concerns the use of non-stationary desorptive measurement techniques for defining the mass diffusivity of cement based materials. Three different procedures are presented: √t-type calculation; logarithmic; and half-time procedures. Cement mortars of different water to cement ratios (w / c), equal to 0.50, 0.65 and 0.80 were selected as the model environment for testing the usability of the above-mentioned desorptive techniques. The study was carried out at the temperature (T) of 20 °C within narrow relative humidity (φ) ranges: from φ₁ = 30% to φ₂ = 12%, and 50% → 30%, 75% → 50%, 85% → 75%, 97% → 85%. The results obtained are used to evaluate the conformity of these methods. The conformity is analyzed with regard to each mortar in all the above humidity ranges Δφ. The values of diffusivity D_m, defined by means of the √t-type calculation and the logarithmic procedure, demonstrated rather high conformity, all relative differences between D_m(√t) and D_m(ln) did not exceeded 20%. However, the half-time procedure can be applied for rough estimation of the diffusivity only. That is because deviations between D_m(t_1 / 2) and the values found by means of the two other methods were too large.