Chinese-Indian-German Collaboration Results that Provided the Impetus for the Foundation of COLLNET

The collaboration model of Kretschmer was applied to the co-authorshipnetwork of Indian medicine with the aim of being able to observe changes instructure over a period of 30 years. The idea of Liang, on her “Distributionof Major Scientific and Cultural Achievements in Terms of Age” was putin relation to the collaboration model by Kretschmer. This revised version was published online in June 2006 with corrections to the Cover Date.     

A design framework for e-business infrastructure integration andresource management

One of the challenges faced by an enterprise with employees in multiple locations is to design a high performance, secure and interoperable distributed computing system (DCS) to interconnect all locations and operations. The problem is computationally hard; hence, subcomponents of it have been studied in detail. These tend to be complex, predominantly theoretical, and somewhat limited from a practical standpoint in terms of providing an integrated solution. Researchers have indicated the need to study the integrated DCS design problem. We merge the complex components and demonstrate that this intrinsically hard problem can be modeled using a component-wise iterative approach. We present a methodology for resource planning and integration that is simple and practical, and can be applied to real-life problems. The methodology includes performance, cost, security and interoperability issues as DCS design objectives. It distributes data and application systems across multiple locations, and aids in security and interoperability configuration, such that the overall design objectives are satisfied. This is one of the first attempts at combining the various components of DCS design and applying it to a real-life problem. The design framework has been successfully used to design a distributed training system for a large, geographically dispersed organization     

Pressure induced order-disorder transition in a diblock copolymer

Polymers are known to undergo order↔order and order↔disorder transitions, when subjected to a change of pressure, temperature, solvent, pH of the medium etc. The molecular processes, which alter the volume of the system, are found to be highly sensitive to the pressure. In the present communication Zimm and Bragg model of helix↔coil transition has been modified to interpret the experimental data of pressure induced phase transition in polystyrene-polybutadiene [PS-PB] at different pressurization rates, as reported by Migler and Han, utilizing the Birefringence and small angle neutron scattering technique. An expression for the degree of order is obtained from the grand partition function for the entire chain in terms of nucleation parameter, which controls the transition width. The nucleation parameter σ increases with the increase in the ODT temperatures of the system. The phenomenon of hysteresis has been discussed in relation to the pressurization rate, which increases/decreases with the corresponding increase/decrease in the pressurization rate. The theoretical transition curves are found to be in good agreement with experimental data.     

Static hole in a two-dimensional antiferromagnet

The energetics of static hole in a 2D antiferromagnetic (AF) is studied. AF is described by magnon operators in the LSW approximation, while the holes by fermionic operators. The energy spectrum of the magnons in the presence of the hole is determined from the perturbed Green’s function.     

Microgrinding of deep micro grooves with high table reversal speed

Recent progress in the miniaturization of electronic items introduces manufacturing challenges for achieving both better surface integrity and high throughput. Controlled thermal interaction processes physically vaporize the material for producing the miniature components but the poor surface and sub-surface characteristics introduce a niche for thermo-mechanical processes, particularly microgrinding. Prior microgrinding attempts have focussed on axi-symmetrical components of hard-brittle materials. For non-axi-symmetrical, high-aspect ratio miniature components, edge chipping was encountered. This paper reports a new grinding method that uses “high table reversal speeds” for reducing the “grit cut load” and hence facilitates the microgrinding process. An arrangement that functions on the principles of four bar linkage with a sliding and rotating pair was devised. This arrangement was designed to reciprocate between 300–1000 strokes/min for a stroke length of 10–70 mm. As a result the table feed rate range was increased from the conventional 300–20 000 mm/min to 5000–55 000 mm/min.Process characterization of the new grinding method was observed for hard-brittle materials. A physical model was developed which links the process parameters with appropriate boundary conditions and the model was verified experimentally. The experimental model was used to explain the mechanism of grinding while employing high table reversal speeds. Process characterization includes grinding force, grinding-ratio, grinding wheel topography, surface finish and SEM study. Also, the process was applied to produce mold-insert which in turn was used for molding the micro-mechanical cantilever sensor parts. Deep slots of size: 1.2×0.1×1.5 mm with an aspect ratio of 15 was successfully produced with this method. The new grinding device and method promote microgrinding through integration to an existing grinder and therefore reduces the additional cost on the capital resources.     

Synthetic and Biological Studies of Sesquiterpene Polygodial: Activity of 9‐Epipolygodial against Drug‐Resistant Cancer Cells

Polygodial, a terpenoid dialdehyde isolated from Polygonum hydropiper L., is a known agonist of the transient receptor potential vanilloid 1 (TRPV1). In this investigation a series of polygodial analogues were prepared and investigated for TRPV1‐agonist and anticancer activities. These experiments led to the identification of 9‐epipolygodial, which has antiproliferative potency significantly exceeding that of polygodial. 9‐Epipolygodial was found to maintain potency against apoptosis‐resistant cancer cells as well as those displaying the multidrug‐resistant (MDR) phenotype. In addition, the chemical feasibility for the previously proposed mechanism of action of polygodial, involving the formation of a Paal–Knorr pyrrole with a lysine residue on the target protein, was demonstrated by the synthesis of a stable polygodial pyrrole derivative. These studies reveal rich chemical and biological properties associated with polygodial and its direct derivatives. These compounds should inspire further work in this area aimed at the development of new pharmacological agents, or the exploration of novel mechanisms of covalent modification of biological molecules with natural products.     

Sinterability of Forsterite Prepared via Solid‐State Reaction

In this work, the sinterability of forsterite powder synthesized via solid‐state reaction was investigated. X‐ray diffraction (XRD) analyses indicate that the synthesized powder possessed peaks that correspond to stoichiometric forsterite. Scanning electron micrographs revealed that the powders were formed agglomerates, which were made up of loosely packed fine particles. Subsequently, the forsterite powders were cold isostatically pressed into a disk shape under 200 MPa and sintered in air at temperature ranging from 1200°C to 1500°C (interval of 50°C) with ramp rate of 10°C/min and dwelling time of 2 h. The sinterability of each sintered samples was examined in terms of phase stability, relative density, Vickers hardness, fracture toughness, and microstructural examination. XRD examination on all the sintered samples exhibited pure forsterite, in which the generated peaks were found to be in a good agreement with JCPDS card no. 34‐0189. The densification of forsterite progressed to reach a maximum relative density of ~91% at 1500°C. This study also revealed that high‐strength forsterite ceramic can be synthesized via solid‐state reaction as forsterite attained favorable mechanical properties, having fracture toughness of 4.88 MPam^1/2 and hardness of 7.11 GPa at 1400°C.     

Effect of different plasticizer on structural and electrical properties of PEMA-based polymer electrolytes

Plasticized poly(vinyl chloride)/poly(ethyl methacrylate) PVC/PEMA-based blend polymer electrolyte films containing lithium perchlorate (LiClO₄) as a salt were prepared by solvent casting technique. The effects of the plasticization on structural, thermal and electrical properties of the plasticized polymer blend electrolytes were investigated. The changes in the structural and complex formation properties of the materials were studied by XRD and FTIR techniques. Dielectric relaxation studies of the polymer electrolyte have been undertaken, and the results are discussed. TG/DTA technique is used to study the thermal stability. Complex impedance analysis is used to calculate the bulk resistance of the complexes. The effect of different plasticizer on the structural and physical properties of polymer blend electrolyte is well correlated.