Parzsweep: A Novel Parallel Algorithm for Volume Rendering of Regular Datasets

The sweep paradigm for volume rendering has previously been successfully applied with irregular grids. This thesis describes a parallel volume rendering algorithm called PARZSweep for regular grids that utilizes the sweep paradigm. The sweep paradigm is a concept where a plane sweeps the data volume parallel to the viewing direction. As the sweeping proceeds in the increasing order of z, the faces incident on the vertices are projected onto the viewing volume to constitute to the image. The sweeping ensures that all faces are projected in the correct order and the image thus obtained is very accurate in its details. PARZSweep is an extension of a serial algorithm for regular grids called RZSweep. The hypothesis of this research is that a parallel version of RZSweep can be designed and implemented which will utilize multiple processors to reduce rendering times. PARZSweep follows an approach called image-based task scheduling or tiling. This approach divides the image space into tiles and allocates each tile to a processor for individual rendering. The sub images are composite to form a complete final image. PARZSweep uses a shared memory architecture in order to take advantage of inherent cache coherency for faster communication between processor. Experiments were conducted comparing RZSweep and PARZSweep with respect to prerendering times, rendering times and image quality. RZSweep and PARZSweep have approximately the same prerendering costs, produce exactly the same images and PARZSweep substantially reduced rendering times. PARZSweep was evaluated for scalability with respect to the number of tiles and number of processors. Scalability results were disappointing due to uneven data distribution

Designing a Waterless Toilet Prototype for Reusable Energy Using a User-Centered Approach and Interviews

User-oriented community engagement can reveal insights into ways of improving a community and solving complex public issues, such as natural resource scarcity. This study describes the early process of co-designing a novel, waterless toilet to respond to the water scarcity problem in the Republic of Korea. It presents how we designed a toilet focusing on three factors???a sanitization function, an ergonomic posture, and clean aesthetics???by conducting focus group interviews as part of a user engagement approach to understand what community users want from a toilet and ways of improving their toilet experiences. The results not only supported the development of an experiential service design project to raise community awareness of water scarcity but also supported scientists and engineers in experimenting with and developing new technologies by collaborating closely with designers

Design of a hybrid fuel burner coupled to a diesel reforming system for energy recovery from waste gas of fuel cell

by Dhanurdhar RamswamyM.Tech

Miscibility studies of HPMC/PEG blends in water by viscosity, density, refractive index and ultrasonic velocity method

Hydroxy propyl methyl cellulose (HPMC)/polyethylene glycol (PEG) blends are edible polymer films used for food packing and directly in foodstuffs. However, they are water-soluble in ordinary temperature and have good mechanical properties. The miscibility of HPMC/PEG blend in water was studied by viscosity, ultrasonic velocity, density and refractive index techniques at 30 and 50 degrees C. Using viscosity data, the interaction parameters mu and alpha were calculated. These values revealed that HPMC/PEG blend is miscible when the HPMC content is more than 60 wt.% in the blend at 30 and 50 degrees C, below which is immiscible. Further the result was also confirmed by ultrasonic velocity, density, refractive index measurements, which also revealed that the change in temperature has no significant effect on the miscibility of HPMC/PEG polymer blend. (C) 2008 Elsevier Ltd. All rights reserved

Secondary structure in solution of two anti-HIV-1 hammerhead ribozymes as investigated by two-dimensional 1H 500 MHz NMR spectroscopy in water

AbstractTwo hammerhead chimeric RNA/DNA ribozymes (HRz) were synthesized in pure form. Both were 30 nucleotides long, and the sequences were such that they could be targeted to cleave the HIV-1 gag RNA. Named HRz-W and HRz-M, the former had its invariable core region conserved, the latter had a uridine in the invariable region replaced by a guanine. Their secondary structures were determined by 2D NOESY 1H 500 MHz NMR spectroscopy in 90% water and 10% D20, following the imino protons. The data show that both HRz-M and HRz-W form identical secondary structures with stem regions consisting of continuous stacks of AT and GT pairs. An energy mimimized computer model of this stem region is provided. The results suggest that the loss of catalytic activity that is known to result when an invariant core residue is replaced is not related to the secondary structure of the ribozymes in the absence of substrate