Exponential and Logarithmic Functions Using Standard CMOS 0.8 μm Technology

The integration of various mathematical functions in ananalogue mode is a growing concern, e.g., for image processingapplications. Specific cells using CMOS technology which performarithmetical operations [1,2] have already been designed. This paperdescribes an extension of the previous cells performing the two mostfundamental transcendental functions: logarithm and exponential. Thedesign of this extension and technological issues are detailed in thispaper. The exponential function is based on MOS transistors operatingin the weak inversion region, in order to behave like bipolar transistors while remaining in a standard CMOS technology.     

2D Model of Guide Vane for Low Head Hydraulic Turbine： Analytical and Numerical Solution of Inverse Problem

Low-head hydraulic turbines are the subjects to individual approach of design. This comes from the fact that hydrological conditions are not of a standard character. Therefore, the design method of the hydraulic turbine stage has a great importance for those who may be interested in such an investment. As a first task in a design procedure the guide vane is considered. The proposed method is based on the solution of the inverse problem within the flame of 2D model. By the inverse problem authors mean a design of the blade shapes for given flow conditions. In the paper analytical solution for the simple cylindrical shape of a guide vane is presented. For the more realistic cases numerical solutions according to the axis-symmetrical model of the flow are also presented. The influence of such parameters as the inclination of trailing edge, the blockage factor due to blade thickness, the influence of loss due to dissipation are shown for the chosen simple geometrical example.     

白化菌对TMP和溶解浆厂运行的影响

生物技术与木材化学、真菌学、生物化学和遗传学结合为制浆造纸工业开发出一种白化真菌产品,在制浆前用其预处理木片,能够降低木材中的树脂含量并提高木片的整体白度,减轻树脂障碍,降低纸浆的漂白要求.有人提出白化菌预处理还能起到纤维改性的作用.最初开发的用于树脂降解的真菌产品Cartapip97,由美国多种Ophiostoma piliferum隔离种群中分离出的囊孢子经传统交配而得到.全球的森林、木片堆和工厂都已经发现腐生子囊菌Ophiostoma piliferum,该真菌通常被看作一种木材变色菌.这种无色真菌的商品名为"CartapipTM97",是一个纯粹的白化菌,没有任何变色作用,已被证实不会对木材或纸浆产生任何有害影响.     

白化菌对TMP和溶解桨厂运行的影响

生物技术与术材化学、真菌学、生物化学和遗传学结合为制浆造纸工业开发出一种白化真菌产品．在制浆前用其预处理木片，能够降低水材中的树脂含量并提高术片的整体白度，减轻树脂障碍．降低纸浆的漂白要求。有人提出白化菌预处理还能起到纤维改性的作用。     

Nuclear microscopy in biomedical analysis with special emphasis on clinical metal biology

Nuclear microscopy based upon developments in high energy ion beam techniques is by now an accepted technique in many fields of research. The advancements into the biomedical field have, however, been slower than expected. A major factor explaining this tendency is the availability of nuclear microscopy. This paper reviews briefly the biomedical work using nuclear microscopy that has been carried out since the 4^th International Conference on Nuclear Microprobe Technology and Applications held in Shanghai. Nuclear microscopy of isolated individual blood cells from patients adversely affected by metal exposure from dental amalgam has been performed both before and after removal of the metallic fillings. The elemental profile of blood cells was more or less normalised after treatment. Some of these results will be presented to illustrate a medical application. Results from bulk analysis by ICP-MS of erythrocytes and plasma before and after treatment will also be presented to illustrate the difference in information content between these two approaches as well as the need for complementary information in solving biomedical problems. As part of a larger study of acute porphyria, nuclear microscopy of blood cells was included among the 78 laboratory tests. The approach in this study was unbiased in the sense that no hypothesis was formulated as to which laboratory parameters would be the most explanatory for health or disease. Multivariate discriminant analysis was applied to the large amounts of data acquired. This approach led to the hypothesis that oxidative stress increased the synthesis of manganese-dependent superoxide dismutase in the mitochondria of polymorphonuclear leukocytes, explaining the increase of manganese in these cells. Antioxidant therapy was therefore applied to a couple of patients with porphyria, however, without clinical success.     

Traumatic Acid Reduces Oxidative Stress and Enhances Collagen Biosynthesis in Cultured Human Skin Fibroblasts

Traumatic acid (TA) is a plant hormone (cytokinin) that in terms of chemical structure belongs to the group of fatty acids derivatives. It was isolated from Phaseolus vulgaris. TA activity and its influence on human cells and organism has not previously been the subject of research. The aim of this study was to examine the effects of TA on collagen content and basic oxidative stress parameters, such as antioxidative enzyme activity, reduced glutathione, thiol group content, and lipid peroxidation in physiological conditions. The results show a stimulatory effect of TA on tested parameters. TA caused a decrease in membrane phospholipid peroxidation and exhibited protective properties against ROS production. It also increases protein and collagen biosynthesis and its secretion into the culture medium. The present findings reveal that TA exhibits multiple and complex activity in fibroblast cells in vitro. TA, with its activity similar to unsaturated fatty acids, shows antioxidant and stimulatory effects on collagen biosynthesis. It is a potentially powerful agent with applications in the treatment of many skin diseases connected with oxidative stress and collagen biosynthesis disorders.     

Potentiometric studies of oxidation–reduction reactions with redox copolymers

Polymeric oxidants in the bead form that were macroporous styrene/divinylbenzene copolymers containing N‐chlorosulfonamide functional groups (in sodium or hydrogen form) or N‐bromosulfonamide groups (in sodium form) were synthesized and investigated to determine their oxidizing powers. The redox potentials of the N‐chlorosulfonamide/sulfonamide and N‐bromosulfonamide/sulfonamide systems were determined by potentiometric studies at different pH values with aqueous solutions of Na₂SO₃, KCN, and KSCN as reducers. The formal redox potentials of the N‐chlorosulfonamide copolymers were 0.79, 0.44, and ?0.12 V at pH's of 1.8, 8.45, and 13.6, respectively. The formal redox potential of the N‐bromosulfonamide copolymer was about 100 mV higher in comparable conditions and in solutions over pH = 5 (e.g., 0.56 V at pH = 8.56). The comparatively higher oxidizing power of the N‐bromosulfonamide copolymer was particularly evident in a strong alkaline medium (in which the N‐chlorosulfonamide copolymer was not reactive). In contrast, the N‐chlorosulfonamide copolymer showed strong oxidative properties in acidic media (in which the N‐bromosulfonamide copolymer decomposed itself). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Diffusion of electrolytes across inhomogeneous permselective membranes

Permeability of sulphuric acid through cation-exchange membranes of different inhomogeneity has been investigated. It has been found that the diffusion coefficient of the acid within the membrane D _i is related to that in the aqueous solution D_0,i by the equation: where V is the membrane volume fraction inaccessible for diffusion. This volume was calculated as the sum of the polymer volume fraction V_p and the volume fraction of the internal solution V_G with the local concentration of the ionogenic groups equal or higher than the concentration of the external electrolyte. Introducing the volume V into the equations by Meares, Prager and Yasuda it is possible to find a high correlation between D _i and f(V), which is related to the membrane structure and their inhomogeneity. The best results have been obtained with the equation of Prager; the calculated diffusion coefficients D_0,i for different membranes are then close to the coefficient of H₂SO₄ in a free aqueous solution.