Selection of master cutter paths in sculptured surface machining by employing curvature principle

In the Isoscallop strategy of sculptured surface machining, one of the surface edges is generally chosen as the Master Cutter Path (MCP)—from which other cutter paths are derived such that the roughness produced is uniform. In this paper, the MCPs have been chosen from the maximum or minimum curvature loci of the surface. Those loci that divide the surface into distinct zones of similar curvature are adopted as MCPs. Secondary cutter path generation is carried out employing standard isoscallop formulation and problems associated with multiple MCPs have been identified and addressed. MCPs along the locus of maximum convex curvature lead to a considerable reduction in machining time while those for minimum curvature (maximum flatness) yield a reduction in CL data file size.     

Association between electrocardiographic ischemic abnormalities and ischemic heart disease risk factors in a Japanese population

This cross-sectional study was undertaken to investigate the association of electrocardiographic (ECG) ischemic abnormalities with ischemic heart disease (IHD) risk factors in a Japanese population. Resting ECGs of 1201 subjects (572 men and 629 women, aged 30 to 89 years), were coded independently by two coders according to the Minnesota Code. Blood pressure (BP) was recorded using a standard sphygmomanometer, and non-fasting serum total cholesterol and high-density lipoprotein cholesterol were measured. Codes 1.1 and 1.2 were classified as myocardial infarction and codes 1.3, 4.1-4.4, 5.1-5.3 and 7.1 were classified as ischemia. Prevalence of ECG with evidence of IHD (IHD ECG) was defined as myocardial infarction and ischemia together. Levels of risk factors were compared between subjects with IHD ECGs and those without IHD ECGs. Multiple logistic regression analysis was used to ascertain the associations between IHD ECG and risk factors. The prevalence of myocardial infarction in the total population was 1.5% and 0.7% in men and women, respectively and the prevalence of IHD ECGs was 10% and 11.3% in men and women, respectively. Systolic blood pressure (SBP) was consistently higher in subjects with IHD ECGs in the total population of both sexes (P < 0.001, P = 0.001 for men and women respectively). Diastolic blood pressure (DBP) was higher only in men with IHD ECGs (P = 0.002). In middle-aged men (aged 30-59 years), total cholesterol was considerably higher in subjects with IHD ECGs, although this relationship was statistically not significant. In multiple logistic regression analysis, SBP was independently associated with IHD ECGs in both sexes (P = 0.001). Associations between IHD ECGs with total cholesterol, alcohol intake and smoking were not statistically significant. This study showed that electro-cardiographic IHD evidences in Japanese are predominantly associated with blood pressure level in both sexes.     

Probing the interface behaviour of injection molded thermoplastics by micro-thermal analysis and temperature-modulated differential scanning calorimetry

Micro-thermal analysis (μTA™) and temperature-modulated differential scanning calorimetry (TMDSC) are emerging as powerful instruments for identifying the existence and quantities of phases in multi-component systems, as well as interfacial properties. In this study, these two complimentary techniques are utilised to probe the interphase behaviour of a polycarbonate/acrylonitrile-styrene-acrylate (PC/ASA) blend as they develop during injection molding. Micro-thermal analysis revealed that parts manufactured at high injection time, pack pressure and melt temperature show a densely packed bulk morphology, a significant amount of particle agglomeration as well as the formation of styrene-acrylonitrile/PC (SAN/PC) interphases. TMDSC qualitatively and quantitatively characterized the PC/ASA's multi-phase morphology and its interfacial properties both before and after injection molding, indicating a greater amount of PC entering the interphase than SAN.     

Institutional organizers and collective action: the case of water users' associations in Gujarat,India

Setting up water users' associations (WUAs) and involving them in the management of delivery systems is an important innovation in improving the performance of public irrigation systems. Most Indian states are in a great hurry to turn over management of “below-the outlet” systems to WUAs. Yet the crucial link between the work done by the institutional organizers who set up these WUAs, the efficacy of the WUAs and the eventual performance of the irrigation systems remains unexplored. This paper attempts to explore this link. It shows that overdrive in the formation of WUAs may reduce their institutional sustainability.     

Preparation and Properties of Halloysite Nanotubes/Poly(ethylene methyl acrylate)-Based Nanocomposites by Variation of Mixing Methods

Halloysite nanotube-based inorganic–organic polymer nanocomposite has been developed with improved mechanical strength in one direction by solution mixing followed by melt mixing. Melt mixing, solution mixing, and melt-cum-solution mixing were performed to optimize the mechanical strength of the nanocomposites. The field emission scanning electron microscopic images and small-angle X-ray scattering spectrum can support the unidirectional array of halloysite nanotubes in the matrix. The tensile properties revealed that solution–melt mixing is the most desired way to develop clay-based nanocomposites. Thermal characterizations implied that thermal stability was improved after nanoclay incorporation. Dynamic mechanical analysis showed the flow properties and the “Payne effect” of the nanocomposites.     

An Agent-Based Connection Management Protocol for Ad Hoc Wireless Networks

Supporting high volume of data transmission in a highly dynamic architecture like Mobile Ad hoc Networks (MANET) still remains a major point of research. In this paper, we have attempted to address the issue of managing an uninterrupted connection between a source and a destination through multiple paths in a temporal domain. We have developed an agent-centric protocol that would accomplish uninterrupted communication over adaptively selected routes. The protocol ensures minimal consumption of network resources. We have organized this work in two logical steps. In the first part, we have described an agent-based framework with its associated protocols and mechanisms. The primary objective of this mobile multiagent framework is to make all nodes in the system topology-aware. We have used the GPS (Global Positioning System) support at each node for the extraction of geographical coordinates, velocity, and direction of movement of each node. The second part of the work attempts to make use of this topology awareness in the context of establishing and managing a connection between two nodes. The agent-enabled proactive replenishment of fresh topology information enables each node to constantly evaluate network conditions and to take decisions on adaptive route selection.