Uranium measurements using laser-induced breakdown spectroscopy in lithium chloride-potassium chloride salt of pyroprocessing

In pyroprocessing,uranium(U) is recovered from molten LiCl-KCl salt,and,for safeguard purposes,it is important to analyze the U and Plutonium(Pu) concentrations in a timely manner.In the present work,salt samples containing U were fabricated.The laser used in the present work was an Nd:YAG laser with a wavelength of 532 nm,a laser energy on the sample of11.5 mJ,and a pulse repetition rate of 10 Hz.The plasma emission light was measured with an Echelle spectrometer.A total of 100 points on the sample surface were measured as the laser incident position was changed.The U and potassium(K) peaks in the spectrum were identified.Univariate and multivariate analyzes were conducted to determine the accuracy and limit of detection(LOD) of the laser-induced breakdown spectroscopy.     

Characterization of functionally gradient epoxy/carbon fibre composite prepared under centrifugal force

Centrifugal force was employed in order to induce a spatial gradient of fibre distribution in the epoxy/carbon fibre system. The gradient structure of the epoxy/carbon fibre composite can be controlled by varying the rotation time and the material parameters, such as fibre length, fibre content and matrix viscosity. The spatial gradient distribution of carbon fibres in an epoxy matrix was achieved by the combined mechanism of packing and settling. The mechanical properties of the functionally gradient epoxy/carbon fibre composite were also investigated. At the same content of carbon fibre, the flexural strength of the functionally gradient composite was higher than that of conventional isotropic composite. This revised version was published online in November 2006 with corrections to the Cover Date.     

GEOMETRICALLY NON-LINEAR AND ELASTOPLASTIC THREE-DIMENSIONAL SHEAR FLEXIBLE BEAM ELEMENT OF VON-MISES-TYPE HARDENING MATERIAL

A three-dimensional elastoplastic beam element being capable of incorporating large displacement and large rotation is developed and examined. Elastoplastic constitutive equations are applied to the beam element based upon the assumption of small deformational strain leading to a material formulation which is completely objective for the application of stress update procedures. The continuum-type equations of plastic model of J₂ mixed hardening are transformed into the beam equations by satisfying beam hypotheses. An effective stress update algorithm is proposed to integrate elastoplastic rate equations by means of the so-called multistep method which is a method of successive control of residuals on yield surfaces. It avoids severe divergence when the displacement increments become large which is usual for the continuation methods. Material tangent stiffness matrix is derived by using consistent elastoplastic modulus resulting from the integration algorithm and is combined with geometric tangent stiffness matrix. Different from other elements, the present element is shear flexible and can satisfy the plasticity condition in a pointwise fashion. A great number of numerical examples are analysed and compared with the literature. The proposed beam element is verified to be not only quite accurate but also very effective for the analyses of pre-buckling and large deflection collapse of spatial framed structures.     

脉冲噪声环境下的恒模盲均衡算法

α稳定分布噪声导致现有的基于梯度下降法的恒模盲均衡算法(SGD-CMA)失效.通过分析厚拖尾噪声对现有算法的影响,给出了2种改造算法,即韧性梯度下降恒模盲均衡算法(SGD-RCMA)和递归最小二乘恒模盲均衡算法(RLS-RCMA).仿真表明2种改造算法比传统的恒模盲均衡算法具有更好的适用性,不仅适用于高斯噪声环境而且适合于脉冲噪声环境.同时RLS-RCMA与SGD-RCMA相比具有更快的收敛速度和更好的码间干扰抑制能力.     

Effect of preparation conditions on the formation of primary ZnO particles in filter expansion aerosol generator

Abstracts are not published in this journal     

EXTENDING THE SHELF LIFE OF SET FISH BALL

Set fish ball is an extruded surimi‐based product that is popular in Singapore and other Southeast Asian countries. Oversetting of set fish ball occurs at chilled temperature during storage. Shelf‐life extension of set fish ball by reducing oversetting conditions and microbial counts were examined. Encapsulated citric acid (CT) and glucono‐delta‐lactone (GDL) were used to reduce oversetting. Acetic acid, GDL and chitosan were used to inhibit the growth of microorganisms. Shelf life was measured for a period of 21 days at 4C. At day 21, a reduction of 46, 56 and 26% in breaking force compared with the control (without additives) was observed for 0.5% GDL, 1.0% GDL and CT, respectively. GDL at 1.0% was shown to be the most effective in controlling the oversetting of set gel. Chitosan (1%) dissolved in acetic acid maintained both aerobic plate and yeast counts at <1 log cfu/g throughout 21 days of storage.     

Solubility of Salmon Myosin as Affected by Conformational Changes at Various Ionic Strengths and pH

The relationship between solubility and conformational changes of salmon ( Oncorhynchus tshawytscha ) myofibrillar proteins at various ionic strengths and pH was investigated using myosin as a model system. Solubility of myosin increased with increased KCl concentration up to 0.5M. Further increasing salt concentration resulted in a gradually reduced solubility. In the absence of salt, myosin was slightly soluble at pH>7 or <4. The increased solubility correlated with the increased surface hydrophobicity and relative sulfhydryl content as well as the decreased α-helicity. At KCl >1.0M, myosin regained its helix structure with a concomitant loss of solubility due to the dominant hydrophobic interaction among nonpolar amino acid residues.