Influence of gamma radiation on the colour strength and fastness properties of fabric using turmeric (Curcuma longa L.) as natural dye

The effect of gamma radiation on the dyeing of cotton with extract of turmeric (Curcuma longa L.) powder has been investigated. Cotton fabric and turmeric powder were irradiated to absorbed doses of 1, 2, 3, 4 and 6 kGy using Co-60 gamma irradiator. Dyeing parameters such as temperature, pH and mordant concentration were optimized. Dyeing was performed using un-irradiated and irradiated cotton with the extracts of un-irradiated and irradiated turmeric powder in order to investigate the effect of radiation treatment on the colour strength of dyed fabric. The reported data of un-irradiated and irradiated fabrics dyed with un-irradiated and irradiated dyes were obtained using the spectraflash SF-650. The colourfastness to light, rubbing- and washing-fastness properties showed that gamma irradiation has improved the dyeing characteristics from fair to good.     

不同堆构条件下颗粒柱有效质量的涨落

利用静态颗粒特性实验仪研究了不同堆构条件下颗粒柱有效质量的涨落.发现当只有一种颗粒堆构时涨落随着颗粒柱与颗粒的直径比的增大而减小,除此之外,当有不同颗粒堆构时涨落还随着不同大小颗粒的堆构位置而变化,可将这种现象的机理归结为颗粒柱中的颗粒数量的异同以及颗粒柱与限界之间摩擦力方向的不确定性.     

Theoretical study of indirect excitons’ lifetime in coupled AlGaN/GaN quantum wells in the presence of an electrostatic trap

The lifetime of electrostatically trapped indirect excitons in a field-effect structure based on coupled AlGaN/GaN quantum wells has been theoretically studied. Within the plane of a double quantum well, indirect excitons are trapped between the surfaces of the AlGaN/GaN heterostructures and a semitransparent metallic top gate. The trapping mechanism has been assumed to be a combination of the quantum confined Stark effect and local field enhancement. In order to study the trapped exciton lifetime, the binding energy of indirect excitons in coupled quantum wells is calculated by finite difference method in the presence of an electric field. Thus, the lifetime of trapped excitons is computed as a function of well width, AlGaN barrier width, the position of double quantum well in the device and applied voltage.     

Cascade-exciton model analysis of level density parameter dependence in proton induced fission cross sections of some sub-actinide nuclei

Fission cross sections strongly depend on the ratio of the level density parameter in fission to neutron emission, a_f/a_n. In this work, a cascade-exciton model implemented in the code CEM95 has been used to observe this effect for proton induced fission cross sections of tungsten, lead and bismuth. The method was employed using different level density parameter ratios for each fission cross section calculation. The calculated fission cross sections are compared with the available experimental data in the literature. It has been observed that a change of the ratio of the level density parameter, a_f/a_n, is necessary with the incident energy of the proton, to best estimate the fission cross sections in CEM95.     

Novel protecting groups in carbohydrate chemistry

Protecting groups play a pivotal role in carbohydrate chemistry. This review describes a selection of protecting groups and protecting group strategies that have been introduced since the beginning of this century.     

Effect of heat transfer on a third grade fluid in a flat channel

The heat transfer analysis on the laminar flow of an incompressible third grade fluid through a porous flat channel is examined. The lower plate is assumed to be at a higher temperature than the upper plate. Analytical solution for temperature distribution is obtained for various values of the controlling parameters and discussed. The obtained analytical solution is also compared with the numerical solution. The comparison shows the fact that the accuracy is remarkable. Copyright © 2009 John Wiley & Sons, Ltd.     

Characteristics of mass and nuclear charge distributions of229th(nth,f). implications for fission dynamics

The mass and nuclear charge distributions of fission fragments from²²⁹Th(n_{th, f}) have been measured at several kinetic energies with the mass spectrometer Lohengrin (ILL-Grenoble). The average proton e-o effect, which reaches 41%, induces large oscillations in the parameters of the isotopic charge distribution. A comparison of the data from different fissile nuclei shows the importance of the last stage of the process for intrinsic excitations.     

Squeezed flow and heat transfer over a porous surface for viscous fluid

Flow and heat transfer over a permeable sensor surface placed in a squeezing channel is analyzed. A constant transpiration through the sensor surface is assumed. Locally non-similar momentum and energy equations are solved by three different methods, against the transpiration parameter τ, for different values of the squeezing parameter b, and Prandtl number Pr. From the investigation, it is found that when the channel being squeezed, the skin-friction reduces but the heat transfer coefficient increases. Increase in the value of the squeezing parameter onsets reverse flow at the sensor surface when fluid is being injected and the affect is enhanced with the increase of injection through the surface. It is further observed that increase of suction of fluid through the sensor thins the thermal and the momentum boundary layer regions, whereas injection of fluid leads to thickening of both the thermal and the momentum boundary layer regions. Heat transfer from the surface of the sensor increases with the increase of the value of Pr for the entire range of surface mass-flux parameter τ. M. A. Hossain is on leave of absence from University of Dhaka.     

Longitudinal distribution of trace elements in the atmosphere of an industrial area from neutron activation analysis

Industrial units play a significant role in atmospheric pollution. Industrial exhausts deteriorate the atmospheric quality causing unhygienic environment for the people working in the vicinity. This work presents a study of the longitudinal distribution of trace elements of the Sheikhupura industrial area. Three kinds of distribution patterns were observed and are discussed in detail. The results are based on the neutron activation analysis of 16 trace elements.     

Interlaminar hygrothermal stresses in laminated plates

Within the elasticity formulation the most general displacement field for hygrothermal problems of long laminated composite plates is presented. The equivalent single-layer theories are then employed to determine the global deformation parameters appearing in the displacement fields of general cross-ply, symmetric, and antisymmetric angle-ply laminates under thermal and hygroscopic loadings. Reddy’s layerwise theory is subsequently used to determine the local deformation parameters of various displacement fields. An elasticity solution is also developed in order to validate the efficiency and accuracy of the layerwise theory in predicting the interlaminar normal and shear stress distributions. Finally, various numerical results are presented for edge-effect problems of several cross-ply, symmetric, and antisymmetric angle-ply laminates subjected to uniform hygrothermal loads. All results indicate high stress gradients of interlaminar normal and shear stresses near the edges of laminates.