13,485 research outputs found

    Study on characteristics behavior of developing nozzle for aerosol spray

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    A new generation of aerosol technology are expand rapidly where the research and development are focused on the analysis of propellants, packaging and ingredients to make the aerosol has a high performance product. However, there are a few main problems with pressurised aerosol spray, which are the production of VOC and the quality of spraying process. Therefore, in this study the development of an internal nozzle has been investigated to analyse the characterictics of spray by using CFD simulation. The analysis is focused on various pressure supply up to 9bar, where the n-butane and water are applied as a liquid phases material. The simulation is done based on two types of selected nozzle design. The result shows that, the values of velocity, TKE and Reynolds Number for both liquid phases are increase when the pressure supply increased. It was observed that, when comparing the two type of nozzle design, it shown that the value of velocity and Reynolds number is relatively similar for both liquid phases, while the TKE value is more difference due to the material properties and nozzle design. Therefore, the use of water is acceptable as an alternative to substitute the n-butane liquid phase in producing an aerosol spray product

    A practical approach to network-based processing

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    The usage of general-purpose processors externally attached to routers to play virtually the role of active coprocessors seems a safe and cost-effective approach to add active network capabilities to existing routers. This paper reviews this router-assistant way of making active nodes, addresses the benefits and limitations of this technique, and describes a new platform based on it using an enhanced commercial router. The features new to this type of architecture are transparency, IPv4 and IPv6 support, and full control over layer 3 and above. A practical experience with two applications for path characterization and a transport gateway managing multi-QoS is described.Most of this work has been funded by the IST project GCAP (Global Communication Architecture and Protocols for new QoS services over IPv6 networks) IST-1999-10 504. Further development and application to practical scenarios is being supported by IST project Opium (Open Platform for Integration of UMTS Middleware) IST-2001-36063 and the Spanish MCYT under projects TEL99-0988-C02-01 and AURAS TIC2001-1650-C02-01.Publicad

    Iowa 100% E News, February 2002, Vol.2, no.2

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    Newsletter for the Information Technology Departmen

    User-centred design of flexible hypermedia for a mobile guide: Reflections on the hyperaudio experience

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    A user-centred design approach involves end-users from the very beginning. Considering users at the early stages compels designers to think in terms of utility and usability and helps develop the system on what is actually needed. This paper discusses the case of HyperAudio, a context-sensitive adaptive and mobile guide to museums developed in the late 90s. User requirements were collected via a survey to understand visitors’ profiles and visit styles in Natural Science museums. The knowledge acquired supported the specification of system requirements, helping defining user model, data structure and adaptive behaviour of the system. User requirements guided the design decisions on what could be implemented by using simple adaptable triggers and what instead needed more sophisticated adaptive techniques, a fundamental choice when all the computation must be done on a PDA. Graphical and interactive environments for developing and testing complex adaptive systems are discussed as a further step towards an iterative design that considers the user interaction a central point. The paper discusses how such an environment allows designers and developers to experiment with different system’s behaviours and to widely test it under realistic conditions by simulation of the actual context evolving over time. The understanding gained in HyperAudio is then considered in the perspective of the developments that followed that first experience: our findings seem still valid despite the passed time

    Operating-system support for distributed multimedia

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    Multimedia applications place new demands upon processors, networks and operating systems. While some network designers, through ATM for example, have considered revolutionary approaches to supporting multimedia, the same cannot be said for operating systems designers. Most work is evolutionary in nature, attempting to identify additional features that can be added to existing systems to support multimedia. Here we describe the Pegasus project's attempt to build an integrated hardware and operating system environment from\ud the ground up specifically targeted towards multimedia

    Applications of computer communications in education.

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    Applications of computer communications can be used in many ways in education. An overview is given of a number of categories of computer communications applications in learning-related activities. Particular attention is given to a new type of system called a course-support environment. In this type of system a database is integrated with Web-based tools and applications, and used to generate a course-support environment accessed via a standard Web browser. Some examples are given. The article moves on to an overview of various issues confronting the acceptance of computer communication systems in educational settings, and indicates some of the ways in which computer communications engineers will have to deal with those issue

    e-Report Generator Supporting Communications and Fieldwork: A Practical Case of Electrical Network Expansion Projects

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    In this piece of work we present a simple way to incorporate Geographical Information System tools that have been developed using open source software in order to help the different processes in the expansion of the electrical network. This is accomplished by developing a novel fieldwork tool that provides the user with automatically generated enriched e-reports that include information about every one of the involved private real estates in a specific project. These reports are an eco-friendly alternative to paper format, and can be accessed by clients using any kind of personal device with a minimal set of technical requirements

    Assessing and Redesigning Enterprise Networks through NS-2 to Support VoIP

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    AbstractIn the recent past, Voice over IP (VoIP) deployments over data networks are gaining popularity due to the massive growth in the broadband internet access. Successful deployment of these applications depends directly on the performance of the underlying data network. Based on this and the fact that today's data networks are operated to perform many significant applications, network administrators seek out a way to measure the impact of these applications on the existing network performance before deploying them. Occasionally, network redesign is necessity; considering redesign's alterations should preserve most of the existing network characteristics to reduce overall impact of deploying new applications in the network performance. In this paper, we evaluated readiness of the existing enterprise network through NS-2 to support VoIP and based on findings a solution for redesigning the enterprise network is proposed to enhance the new network performance and leaving sufficient capacity for future growth. We applied our approach on a medium size enterprise network as a case study, the results prove improvements in network performance after redesigning the existing enterprise network
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