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Pollack Periodica
Authors: Iulia Tuca, Viorel Ungureanu, Adrian Ciutina, and Dan Dubina

-formed shear panels under monotonic and cyclic loading, Part I, Experimental Research, Thin Walled Structures , Vol. 42, No. 2, 2004, pp. 321–338. Dubina D. Performance of wall-stud cold

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, S. P. , Zhou , P. and Yu , D. S. , Ultimate generalization for monotonicity for uniform convergence of trigonometric series , arXiv: math.CA/0611805 v1 November 27, 2006 , preprint; Science China , 53 ( 2010 ), 1853 – 1862

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remark on “two-sided” monotonicity condition: an application to L p convergence, Acta Math. Hungar. 113 (2006), no. 1–2, 159–169. MR 2007f :42006 Le R. J. A remark on

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Abstract  

A copper, zinc and aluminium mixed oxides sample having the nominal composition 0.25 CuO/0.03 ZnO/Al2O3 was prepared by impregnating Al(OH)3 with copper and zinc nitrate solutions, drying at 100 °C then heating in air at 600 °C. The obtained solid was exposed to different doses of -rays (20–160 Mrad). The surface characteristics namelyS BETVP andr of different treated adsorbents were determined from N2 adsorption isothems measured at –196 °C. The catalytic activity of various irradiated solids was determined by following up the kinetics of CO-oxidation by O2 at 150–200 °C. The results showed that the doses up to 80 Mrad resulted in no significant change in theS BET but increased slightly theV P (20%) of the treated adsorbents. The irradiation at 160 Mrad caused an increase of 20% in theS BET of the irradiated solid sample. The catalytic activity increased progressively by increasing the dose, a dose of 160 Mrad brought about an increase of 140% in the catalyst's activity. The apparent activation energy of the catalytic reaction decreased monotonically by increasing the absorbed dose of -rays which was attributed to a parallel induced decrease in the value of pre-exponential term of the Arrhenius equation. The observed increase in the catalytic activity due to -irradiation has been interpreted as a result of increasing the concentration of catalytically-active sites contributing in chemisorption and catalysis of CO-oxidation via a possible fragmentation of CuO crystallites.

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The instantaneous elastic moduli for a nylon-6 monofilament were derived on strain recoveries right after creep, stress relaxation, and rapid elongation,E c,E s andE e, respectively. It was found that during strain recoveryE s(>E e) andE e increase monotonically with increasing load,m 1, on the sample. The extrapolated value of Es atm 1=0 g is almost equal to Young's modulus, 4.06 GPa. The value ofE c also increased with increasingm 1, and atm 1=600 g (1.93 t cm−2) reached about 14 GPa. The endothermic heat change right after creep, stress relaxation or rapid elongation,Q, was negligibly small. For comparison,E s,E c andQ were also investigated for silicone rubber. It was found thatE s (53.8 M Pa at the draw ratioD=1.2) decreased abruptly atD=1.3. In the range ofD=1.4–1.9,E s was only 22.6 MPa. In the case of stress relaxation,Q increased with increasingD from 4 J mol−1 (atD=1.2) to 56 J mol−1 (atD=1.9). FurthermoreE c (5.58 MPa atm 1=133.8 g (429.4 kg cm−2)) increased gradually with increasing m1 and attained 16.6 MPa atm 1=548.4 g (1.76 t cm−2). In the case of creep,Q was in the range of 0–11.5 J mol−1 and larger when larger loads,m 2 were removed during the later stages of creep.

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Abstract  

Flow birefringence (FB) has been investigated in solutions of products of hydrolytic degradation of poly(naphthoyleneimide benzimidazole) (PNIB) in 96% sulphuric acid PNIB solutions have previously been subjected to heating at various temperatures from 65 to 120°C and then investigated at 22°C by FB and viscometry. A monotonic decrease in intrinsic viscosity and the molecular weightM of thermal degradation products with increasing degradation temperature was detected. At the same time, the shear optical coefficients in series of products with decreasingM first increases and then, at treatment temperatures exceeding 90°C, decreases with decreasing [ν] in accordance with decreasingM of the product. Possible reasons for the detected anomaly have been discussed.

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Abstract  

The influence of heat treatment of a liquid phase on “melting-crystallization” processes of silver thiogallate (AgGaS2) having chalcopyrite structure I
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\bar{4}2{\text{d}}$$ \end{document}
, has been studied by the method of statistical thermal analysis (STA). It is shown that the melting temperature of solid phase (T m) increases non-monotonic from 970 °C due to rise in the preliminary melt overheating, and T m reaches asymptotically 1010 °C. The equilibrium melting-crystallization temperature (
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$T_{\text{m}}^{\text{o}}$$ \end{document}
) has been defined as 989.2 °C. It is also found an extreme dependence of the melt supercooling on its overheating. The two curves of irregular dependence of nucleation rate on melt supercooling have been plotted at different melt overheating.
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Journal of Thermal Analysis and Calorimetry
Authors: R. De Lisi, G. Lazzara, S. Milioto, and N. Muratore

Abstract  

Macromolecule/laponite nanomaterials were studied by DSC and X-ray diffraction techniques. The matrices are poly(ethylene) glycols at various molecular masses and poly(ethylene oxides)-poly(propylene oxides)-poly(ethylene oxides) tri-block copolymers. The latter were tuned by modulating the molecular masses, at constant hydrophilic/hydrophobic ratio, and the hydrophilicity. For all the investigated systems, the enthalpy of melting (ΔH m) is nearly constant up to a given composition thereafter it increases monotonically reaching the value of the pure macromolecule. We proposed a model to interpret the DSC data. Briefly, it was invoked a mechanism of interaction following which some segments of the adsorbed macromolecule are anchored to the laponite (RD) particles and the remaining segments are radiating away from the surface. The portion of the macromolecule in contact with RD does not contribute to ΔH m whereas that radiating away from the clay does. Once that the RD surface is saturated, the excess of the macromolecule behaves like the pure one. The proposed model allowed to compute successfully the ΔH m values. The X-ray diffraction experiments ruled out the polymer intercalation between the silicate sheets.

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Abstract  

The Hg-, Cd- and UO2-targets bombarded by protons have been treated using the sublimation and evaporation techniques. The Hg and Cd nuclei have been separated from non-isotopic products by distillation in the hydrogen stream. The separation of the groups of Re, Os, Ir, Mo, Tc and Ru oxides has been carried out in the air stream. No monotonic temperature dependence of the Tl, Ru, Mo, Tc, Te, Pb and Po release has been observed in the oxidation of the UO2-ceramics in the air stream. The values of (−ΔH a 0 ) of volatile products adsorbed on quartz have been determined from the chromatographic data. The relation between the adsorption heat (−ΔH a 0 ) and the standard sublimation heat (ΔH 298 0 subl.) has been found to be linear, i.e. −ΔH a 0 =(4.04±1.97)+(0.69±0.04)ΔH 298 0 (subl.). As an example of the thermochromatographic generator of isotopes, the separation of99Mo to99mTc has been investigated.

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Dual-steel structural systems, in which mild carbon steel is used in dissipative members while high strength steel is used in non-dissipative ‘elastic’ members, can be very reliable and cost efficient. Because present seismic design codes do not cover this specific configuration, a research project started with the aim to investigate and evaluate the seismic performance of dual-steel building frames. The frames are considered to be moment resisting frames, dual concentrically braced frames and dual eccentrically braced frames. The paper makes a short description of the research project and the experimental program to be performed at the ‘Politehnica’ University of Timisoara.A number of numerical simulations have been performed for the beam-to-column joints that will be tested with the aim to assess their behavior under monotonic as well as cyclic loading. The material model used in the numerical simulations was calibrated based on the results from tensile tests. The assumptions considered in the modeling of the specimens, the loading procedure, as well as the results from the numerical analysis are finally presented.

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