印度连铸发展概况

尽管印度钢铁工业采用连铸工艺可以追溯到20世纪60年代,但是直到80年代早期,钢铁联合企业才部分选择使用这项技术,它的应用才有突破性进展.从此,连铸在印度有了重大发展,到90年代中期,几乎所有的钢铁联合企业都部分或全部采用这种技术.今天超过65%的印度钢材是通过连铸工艺生产的.同时由于新技术的引进,机械设计和制造工序也经历了重大的变革.2003年,印度钢产量达3180万t,其中有2080万t是通过连铸工艺生产的.现在,印度采用连铸工艺生产的钢材有进一步增长的趋势,尤其是难浇铸钢种、双相钢和其它特种钢.笔者试图对当前印度连铸工艺概况进行全面评价.连铸工艺在印度具有巨大的发展潜力,未来的印度钢材几乎100%将要通过连铸生产.     

Antidiabetic activity and molecular docking of fructooligosaccharides produced by Aureobasidium pullulans in poloxamer-407-induced T2DM rats

This study evaluated the beneficial effects of fructooligosaccharide (FOS) intake from Aureobasidium pullulans using poloxamer-407 (PX-407) induced type 2 diabetes mellitus (T2DM) in rat. Administration of FOS enhanced enzymatic activities of catalase and glutathione reductase in a dose-dependent manner. Significant reduction in fasting plasma triacylglycerol and very low-density lipoprotein level coupled with slight increase in fasting plasma insulin level was observed. Significant decrease in severe glucosuria, proteinuria, blood creatinine, urea and advanced glycation end products was also observed. Supplementation of FOS increased glucagon like peptide-1 content as well as Bifidobacteria and Lactobacilli populations in the caecum. Molecular docking by Gold and Glide software revealed that three sugar types present in the FOS (1-kestose, nystose, and 1-β-fructofuranosyl nystose) are potent dipeptidyl peptidase-IV inhibitors as well as peroxisome proliferator-activated receptor-gamma agonists. This work indicates that FOS can be positioned as a nutraceutical product, beneficial in diabetes-associated metabolic abnormalities.     

On the asymmetry of flow through a bifurcated channel

Summary Results are presented of detailed numerical simulation of spatially developed, three-dimensional laminar flow through a bifurcated channel for different inlet flow conditions. The flow development near the bifurcated part of the channel is observed to be very sensitive to the inlet velocity distribution. For an uniform axial inlet velocity, the flow visualization results indicate the formation of two counter rotating symmetric vortical structures, parallel to the port axis, in the bifurcated part of the channel. When a cross-flow (v-component of velocity) is introduced at the inlet, the flow behaviour near the bifurcated part of the channel changes drastically. For such an inlet flow condition one vortical structure becomes larger at the expense of the other, and the asymmetry prevails in the flow field. The phenomena get intensified with the increase of the Reynolds number. The present numerical prediction of the flow phenomena provides some explanation of the interesting observations reported in the previous experimental investigations.     

Surface-enhanced Raman spectroscopy of self-assembled monolayers: sandwich architecture and nanoparticle shape dependence

Surface enhanced Raman scattering (SERS) spectra of 4-mercaptobenzoic acid (4-MBA) self-assembled monolayers (SAMs) on gold substrates is presented for SAMs onto which gold nanoparticles of various shapes have been electrostatically immobilized. SERS spectra of 4-MBA SAMs are enhanced in the presence of immobilized gold nanocrystals by a factor of 10(7)-10(9) relative to 4-MBA in solution. Large enhancement factors are a likely result of plasmon coupling between the nanoparticles (localized surface plasmon) and the smooth gold substrate (surface plasmon polariton), creating large localized electromagnetic fields at their interface, where 4-MBA molecules reside in this sandwich architecture. Moreover, enhancement factors depend on nanoparticle shape and vary by a factor of 10(2). This SERS geometry offers large surface enhancements for molecules adsorbed onto planar substrates and could be quite useful for determining chemical information for poor Raman scatterers from assays on 2-D substrates.     

Successful Implementation of eRx Systems: Creating Technology–Organization Alignment using the Strategy-Map Approach

The adoption rates of eRx systems continue to be low and their implementation remains uneven. Rooted in the theories of technology–organization alignment and strategy maps, this article develops a framework for successful implementation of eRx systems. The proposed strategy map outlines the key strategic processes that would make implementation of eRx systems not only feasible and successful, but also a profitable venture for healthcare organizations.     

Parameterized Domination in Circle Graphs

A circle graph is the intersection graph of a set of chords in a circle. Keil [Discrete Appl. Math., 42(1):51–63, 1993] proved that Dominating Set, Connected Dominating Set, and Total Dominating Set are NP-complete in circle graphs. To the best of our knowledge, nothing was known about the parameterized complexity of these problems in circle graphs. In this paper we prove the following results, which contribute in this direction:

• Dominating Set, Independent Dominating Set, Connected Dominating Set, Total Dominating Set, and Acyclic Dominating Set are W[1]-hard in circle graphs, parameterized by the size of the solution.
• Whereas both Connected Dominating Set and Acyclic Dominating Set are W[1]-hard in circle graphs, it turns out that Connected Acyclic Dominating Set is polynomial-time solvable in circle graphs.
• If T is a given tree, deciding whether a circle graph G has a dominating set inducing a graph isomorphic to T is NP-complete when T is in the input, and FPT when parameterized by t=|V(T)|. We prove that the FPT algorithm runs in subexponential time, namely $2^{\mathcal{O}(t \cdot\frac{\log\log t}{\log t})} \cdot n^{\mathcal{O}(1)}$ , where n=|V(G)|.

     

Effect of Dispersoid Size and Volume Fraction on Aging Behavior and Mechanical Properties of TiO2-Dispersed AA7075 Alloy Composites

TiO₂-dispersed AA7075 alloy composites were produced by mechanical milling followed by hot uniaxial compaction and sintering. The effects of volume fraction and dispersoid size on precipitation kinetics, densification, and hardness of the composites were studied in detail. While the sinterability of the composites decreases with increasing volume fraction of the particulate reinforcement (dispersoid), the same increases with decreasing particle size of the reinforcement. Microstructural analysis using X-ray diffraction and scanning electron microscopy shows an improvement in the distribution of reinforcement with decreasing particle size. The hardness of the composites increases with increasing volume fraction and decreasing TiO₂ particle size. Further, the reinforced composites do not show age hardenability unlike unreinforced AA7075 alloy. Microstructural analysis reveals the formation of MgTiO₃ and ZnO near the TiO₂-AA7075 interface, which suppresses the formation of Guinier-Preston (GP) zone resulting in no age hardenability of the composites.     

Mathematical modeling of retinal birefringence scanning.

Retinal birefringence scanning (RBS) is a new technique that is used to detect the fixation of the eye remotely and noninvasively. The method is based on analysis of polarization changes induced by the retina. In this study, the principles of RBS were mathematically modeled to facilitate a better understanding of the origins of the signals obtained. Stokes vector analysis and Mueller matrix multiplication were augmented with Poincaré sphere representation. The cornea was modeled as a linear retarder. The foveal area was modeled as a radially symmetric birefringent medium. The model accurately predicted the frequency and phase of RBS signals obtained during central and paracentral fixation. The signal that indicates central fixation during RBS likely results from a combination of the radial birefringence of the Henle fibers and the overlying corneal birefringence.     

Highly flexible and bendable free-standing thin film polymer for battery application

Highly flexible and bendable free-standing polypyrrole (PPy) films were prepared using the electrochemical polymerization method. The paper-like films are soft, lightweight, mechanically robust, and highly electrically conductive. The morphologies and electrochemical behaviour of the free-standing pure PPy films were affected by the electrochemical polymerization conditions. The free-standing films show promise as cathodes for flexible and bendable batteries.