Effects of processing parameters on the mechanical properties of polypropylene random copolymer

The mechanical properties of polypropylene random copolymer (PP-R) with different processing parameters were studied. Special attention is devoted to the investigation of the influence of masterbatch addition on the variation in the mechanical properties of injection moulded PP-R. Tensile, instrumented Charpy impact, Shore D hardness, differential scanning calorimeter (DSC) and Vicat softening temperature (VST) tests were conducted on the test samples containing different colour masterbatches varying from 0.5 to 10 wt%. The observed changes in the mechanical behaviour are explained by the type and level of masterbatch content. The natural UV weathering performance of the PP-R material was studied from the masterbatch type point of view. The effect of processing parameters on material performance was studied on samples which were directly obtained from extruded pipes and on injection moulded samples.

Finally, the effects of storage time on the polymer properties were investigated.     

Analytical and approximate solutions of(2+1)-dimensional time-fractional Burgers-Kadomtsev-Petviashvili equation

In this paper, we applied the sub-equation method to obtain a new exact solution set for the extended version of the time-fractional Kadomtsev-Petviashvili equation, namely BurgersKadomtsev-Petviashvili equation(Burgers-K-P) that arises in shallow water waves.Furthermore, using the residual power series method(RPSM), approximate solutions of the equation were obtained with the help of the Mathematica symbolic computation package. We also presented a few graphical illustrations for some surfaces. The fractional derivatives were considered in the conformable sense. All of the obtained solutions were replaced back in the governing equation to check and ensure the reliability of the method. The numerical outcomes confirmed that both methods are simple, robust and effective to achieve exact and approximate solutions of nonlinear fractional differential equations.     

Viscous dissipation effect on heat transfer characteristics of rectangular microchannels under slip flow regime and H1 boundary conditions

Viscous dissipation effect on heat transfer characteristics of a rectangular microchannel is studied. Flow is governed by the Navier–Stokes equations with the slip flow and temperature jump boundary conditions. Integral transform technique is applied to derive the temperature distribution and Nusselt number. The velocity distribution is taken from literature. The solution method is verified for the case where viscous dissipation is neglected. It is found that, the viscous dissipation is negligible for gas flows in microchannels, since the contribution of this effect on Nu number is about 1%. However, this effect should be taken into account for much more viscous flows, such as liquid flows. Neglecting this effect for a flat microchannel with an aspect ratio of 0.1 for Br=0.04 underestimates the Nu number about 5%.     

Search for top quark FCNC couplings in Z′ models at the LHC and CLIC

The top quark is the heaviest particle to date discovered, with a mass close to the electroweak symmetry breaking scale. It is expected that the top quark would be sensitive to the new physics at the TeV scale. One of the most important aspects of the top quark physics can be the investigation of the possible anomalous couplings. Here, we study the top quark flavor changing neutral current (FCNC) couplings via the extra gauge boson Z′ at the Large Hadron Collider (LHC) and the Compact Linear Collider (CLIC) energies. We calculate the total cross sections for the signal and the corresponding Standard Model (SM) background processes. For an FCNC mixing parameter x=0.2 and the sequential Z′ mass of 1 TeV, we find the single top quark FCNC production cross sections 0.38(1.76) fb at the LHC with $\sqrt{s_{pp}}=7(14)$ TeV, respectively. For the resonance production of sequential Z′ boson and decays to single top quark at the Compact Linear Collider (CLIC) energies, including the initial state radiation and beamstrahlung effects, we find the cross section to be 27.96(0.91) fb at $\sqrt{s_{e^{+}e^{-}}}=1(3)$ TeV, respectively. We make the analysis to investigate the parameter space (mixing-mass) through various Z′ models. It is shown that the results benefit from the flavor tagging.     

Phenolic compounds from Scorzonera latifolia (Fisch. & Mey.) DC

A new 3-benzylphthalide, scorzoveratrin 4'-O-β-glucoside (1), together with the known 3-benzylphthalides, scorzoveratrin (2) and scorzoveratrozit (3), the caffeoyl derivatives, chlorogenic acid methyl ester (4), 4,5-dicaffeoylquinic acid (5), 4,5-dicaffeoylquinic acid methyl ester (6), 3,5-dicaffeoylquinic acid (7) and caffeic acid (8) were isolated from the subaerial parts of Scorzonera latifolia (Fisch. & Mey.) DC. All secondary metabolites were assigned using physicochemical and spectroscopic data. The known compounds 2-8 were isolated for the first time from this species.     

新型二氧代氮杂茂并[3’,4’-d]N-甲基异噁唑四氯化铁酸盐衍生物的合成及其生物活性

硫酸二甲酯作为N-甲基化试剂,与相应的异噁唑啉反应,并在盐酸中三氯化铁作为阴离子交换试剂,合成了15个未见文献报道的2-甲基-3-(1’,2’-二-O-环亚己基二氧乙基)-5-芳基-3a,6a-二氢-4,6-二氧代氮杂茂并[3’,4’-d]异噁唑四氯化铁酸盐衍生物4a～4o.化合物4a～4o结构结构经1H NMR,IR和元素分析确证,并进行了初步药物活性筛选,大部分化合物显示了不同程度的抗癌和抗炎症性及免疫性疾病活性.体外抗癌活性试验表明,当样品浓度为20μg/mL时,除了4h无活性外,其余化合物对细胞分裂周期磷酸酯酶Cdc25B的抑制率为≥97.55%.此外,体外白细胞共同抗原活性试验表明,当样品浓度为20μg/mL时,所有化合物4a～4o对白细胞共同抗原CD45蛋白酪氨酸磷酸酶A具有良好的抑制活性,其抑制率为68.41%～93.38%.在此基础上,初步讨论了该类化合物的构效关系.     

In Vitro Inhibition Effect of Some Dihydroxy Coumarin Compounds on Purified Human Serum Paraoxonase 1 (PON1)

Human serum paraoxonase 1 (PON1; EC 3.1.8.1) is a high-density lipoprotein associated, calcium-dependent enzyme that hydrolyses aromatic esters, organophosphates and lactones and can protect the low-density lipoprotein against oxidation. In this study, in vitro inhibition effect of some dihydroxy coumarin compounds namely 6,7-dihydroxy-3-(2-methylphenyl)-2H-chromen-2-one (A), 6,7-dihydroxy-3-(3-methylphenyl)-2H-chromen-2-one (B) and 6,7-dihydroxy-3-(4-methylphenyl)-2H-chromen-2-one (C) on purified PON1 were investigated by using paraoxon as a substrate. PON1 was purified using two-step procedures, namely ammonium sulphate precipitation and Sepharose-4B-l-tyrosine-1-naphthylamine hydrophobic interaction chromatography. The purified enzyme had a specific activity of 11.76?U/mg. The dihydroxy coumarin derivatives of A and B compounds inhibited PON1 enzyme activity in a noncompetitive inhibition manner with K _i of 0.0080?±?0.256 and 0.0003?±?0.018?mM values, respectively. C compound exerted an uncompetitive inhibition of PON1 enzyme activity with K _i of 0.0010?±?0.173?mM. Moreover, dihydroxy coumarin derivatives of A, B and C compounds were effective inhibitors on purified human serum PON1 activity with IC₅₀ of 0.012, 0.022 and 0.003?mM values, respectively. IC₅₀ value of unsubstituted 6,7 dihydroxy coumarin was found as 0.178?mM. The present study has demonstrated that PON1 activity is very highly sensitive to studied coumarin derivatives.     

On an inverse scattering problem for a class of Dirac operators with spectral parameter in the boundary condition

In this work, we consider the inverse scattering problem for a class of one dimensional Dirac operators on the semi-infinite interval with the boundary condition depending polynomially on a spectral parameter. The scattering data of the given problem is defined and its properties are examined. The main equation is derived, its solvability is proved and it is shown that the potential is uniquely recovered in terms of the scattering data. A generalization of the Marchenko method is given for a class of Dirac operator.