245 research outputs found
Understanding Next-Generation VR: Classifying Commodity Clusters for Immersive Virtual Reality
Commodity clusters offer the ability to deliver higher performance computer graphics at lower prices than traditional graphics supercomputers. Immersive virtual reality systems demand notoriously high computational requirements to deliver adequate real-time graphics, leading to the emergence of commodity clusters for immersive virtual reality. Such clusters deliver the graphics power needed by leveraging the combined power of several computers to meet the demands of real-time interactive immersive computer graphics.However, the field of commodity cluster-based virtual reality is still in early stages of development and the field is currently adhoc in nature and lacks order. There is no accepted means for comparing approaches and implementers are left with instinctual or trial-and-error means for selecting an approach.This paper provides a classification system that facilitates understanding not only of the nature of different clustering systems but also the interrelations between them. The system is built from a new model for generalized computer graphics applications, which is based on the flow of data through a sequence of operations over the entire context of the application. Prior models and classification systems have been too focused in context and application whereas the system described here provides a unified means for comparison of works within the field
Masters Students' Experiences of Learning to Program: An Empirical Model
The investigation reported here examined how Masters students experience learning to program. The phenomenographic research approach adopted permitted the analysis of 1) how students go about learning to program, that is the ‘Act’ of learning to program, and 2) what students understand by ‘programming’, that is the ‘Object’ of learning to program. Analysis of data from twenty-three participants identified five different experiences of the Act of learning to program and five different experiences of the Object of learning to program. Together the findings comprise an empirical model of the learning to program experience amongst the participating students. We suggest how our findings are significant for programming teachers and offer tools to explore students’ views
Immobilization of glucose oxidase on acid activated-bentonite and its performance examination
Glucose oxidase (GOx) was immobilized on acid activated-bentonite. The activation of bentonite was carried out by adding 1-3 M of hydrochloric acid, and the immobilized GOx enzymes were examined for the oxidation of glucose solution under certain conditions. Besides, the effect of pH and working temperature were also investigated. The result showed that the immobilized GOx increased the rate of catalytic reaction. The optimalcatalytic activityof immobilized GOxwas at 30oC and pH 7. The values achieved for the Michaelis-Menten constant (Km) andand maximum reaction rate (Vmax) were 48.01 mM and 5.41 x 10-3mM.min-1, respectively.The result also showed that effectiveness factor was0.68. Immobilization of GOx on acid activated-bentonite also provides a stable matrix shown by the ability to reuse it up to seven times before its activity decreases to a level of 68%. Keywords: bentonite, glucose oxidase, immobilized enzymes, oxidation, glucose.1. IntroductionEnzymes are protein molecules that reduce the activation energy to accelerate chemical reactions in living cells. However, some of these uses require immobilization of molecules. The enzyme molecule is often used without losing its activity and might be used repeatedly and continuously [1,2]. The immobilization development has increased where they are used as biocatalysts in textile industries and other applications [3-6]. The use of immobilized enzymes is preferred because of their repeated use, the ease of harvesting products, and their greater stability. Glucose oxidase enzyme (GOx) is used as a reagent in the glucose determination in blood, though it is always costly [7, 8]. The development of immobilized enzyme technology has always received attention [8]. For instance, explorations relating to immobilized GOxhave been carried out many times in recent years. The process ofimmobilizing biomolecules using insoluble support materials is critical in the fabrication of various functional materials [9]
Laser powder bed fusion of soda lime silica glass: Optimisation of processing parameters and evaluation of part properties
© 2021 The Authors. Published by Elsevier B.V. his is an open access article under the CC BY license. https://creativecommons.org/licenses/by/4.0/Glass has a number of attractive properties, such as transparency, chemical resistance, good thermal stability and high electrical resistivity, that make it a favourable material for a range of applications, including medical technology, electronics, chemical and pharmaceutical industries. However, compared to metals and polymers, the additive manufacturing of glass is still at a primitive stage. The inherent material properties of glass, i.e. its amorphous structure, lack of ductility and high processing temperatures, make processing of glass by additive manufacturing challenging. This paper describes the laser powder bed fusion of a soda lime silica glass. Optimisation of the laser powder bed fusion process was undertaken and the physical and mechanical properties of the manufactured parts were characterised revealing an average porosity of 12%, a mean flexural strength of 6.5 MPa and a fully amorphous structure. Feasibility examples were successfully demonstrated, indicating that geometrically complex shapes are possible. Even though the manufactured parts are opaque, they could potentially find use in applications where the need for chemical inertness and geometrical complexity surpass the need for transparency as in the chemical and pharmaceutical industries e.g. in the form of continuous flow reactors or structured catalysts.Peer reviewedFinal Published versio
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The effects of elevated CO2 and eutrophication on surface elevation gain in a European salt marsh.
Salt marshes can play a vital role in mitigating the effects of global environmental change by dissipating incident storm wave energy and, through accretion, tracking increasing water depths consequent upon sea level rise. Atmospheric CO2 concentrations and nutrient availability are two key variables that can affect the biological processes that contribute to marsh surface elevation gain. We measured the effects of CO2 concentrations and nutrient availability on surface elevation change in intact mixed-species blocks of UK salt marsh using six open-top chambers receiving CO2 -enriched (800Â ppm) or ambient (400Â ppm) air. We found more rapid surface elevation gain in elevated CO2 conditions: an average increase of 3.4Â mm over the growing season relative to ambient CO2 . Boosted regression analysis to determine the relative influence of different parameters on elevation change identified that a 10% reduction in microbial activity in elevated CO2 -grown blocks had a positive influence on elevation. The biomass of Puccinellia maritima also had a positive influence on elevation, while other salt marsh species (e.g. Suaeda maritima) had no influence or a negative impact on elevation. Reduced rates of water use by the vegetation in the high CO2 treatment could be contributing to elevation gain, either directly through reduced soil shrinkage or indirectly by decreasing microbial respiration rates due to lower redox levels in the soil. Eutrophication did not influence elevation change in either CO2 treatment despite doubling aboveground biomass. The role of belowground processes (transpiration, root growth and decomposition) in the vertical adjustment of European salt marshes, which are primarily minerogenic in composition, could increase as atmospheric CO2 concentrations rise and should be considered in future wetland models for the region. Elevated CO2 conditions could enhance resilience in vulnerable systems such as those with low mineral sediment supply or where migration upwards within the tidal frame is constrained.Marie Curie Incoming International Fellowship (Grant ID: FP7-PEOPLE-IIF 623720 STORM)This is the author accepted manuscript. The final version is available from Wiley via https://doi.org/10.1111/gcb.1339
3D printed fluidics with embedded analytic functionality for automated reaction optimisation
Additive manufacturing or ‘3D printing’ is being developed as a novel manufacturing process for the production of bespoke micro- and milliscale fluidic devices. When coupled with online monitoring and optimisation software, this offers an advanced, customised method for performing automated chemical synthesis. This paper reports the use of two additive manufacturing processes, stereolithography and selective laser melting, to create multifunctional fluidic devices with embedded reaction monitoring capability. The selectively laser melted parts are the first published examples of multifunctional 3D printed metal fluidic devices. These devices allow high temperature and pressure chemistry to be performed in solvent systems destructive to the majority of devices manufactured via stereolithography, polymer jetting and fused deposition modelling processes previously utilised for this application. These devices were integrated with commercially available flow chemistry, chromatographic and spectroscopic analysis equipment, allowing automated online and inline optimisation of the reaction medium. This set-up allowed the optimisation of two reactions, a ketone functional group interconversion and a fused polycyclic heterocycle formation, via spectroscopic and chromatographic analysis
Polychlorinated Biphenyl (PCB) Exposure and Diabetes: Results from the Anniston Community Health Survey
Background: Polychlorinated biphenyls (PCBs) manufactured in Anniston, Alabama, from 1929 to 1971 caused significant environmental contamination. The Anniston population remains one of the most highly exposed in the world
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