6,380 research outputs found
Empirical measurements of small unmanned aerial vehicle co-axial rotor systems
Small unmanned aerial vehicles (SUAV) are beginning to dominate the area of intelligence, surveillance, target acquisition and reconnaissance (ISTAR) in forward operating battlefield scenarios. Of particular interest are vertical take-off and landing (VTOL) variants. Within this category co-axial rotor designs have been adopted due to their inherent advantages of size and power to weight ratio. The inter-rotor spacing attribute of a co-axial rotor system appears to offer insight into the optimum design characteristic. The H/D ratio has been cited as a significant factor in many research papers, but to date has lacked an empirical value or an optimal dimensionless condition. In this paper the H/D ratio of a SUAV has been explored thoroughly, reviewing the performance of these systems at incremental stages, the findings from this study have shown that a range of H/D ratios in the region of (0.41-0.65) is advantageous in the performance of SUAV systems. This finding lends itself to the theory of inter-rotor spacing as a non-dimensionally similar figure, which cannot be applied across a spectrum of systems; this could be attributed to the viscous losses of flight at low Reynolds Numbers (< 50,000
Revisiting revisitation in computer interaction: organic bookmark management.
According to Milic-Frayling et al. (2004), there are two general ways of user browsing i.e. search (finding a website where the user has never visited before) and revisitation (returning to a website where the user has visited in the past). The issue of search is relevant to search engine technology, whilst revisitation concerns web usage and browser history mechanisms. The support for revisitation is normally through a set of functional built-in icons e.g. History, Back, Forward and Bookmarks. Nevertheless, for returning web users, they normally find it is easier and faster to re-launch an online search again, rather than spending time to find a particular web site from their personal bookmark and history records. Tauscher and Greenberg (1997) showed that revisiting web pages forms up to 58% of the recurrence rate of web browsing. Cockburn and McKenzie (2001) also stated that 81% of web pages have been previously visited by the user. According to Obendorf et al. (2007), revisitation can be divided into four classifications based on time: short-term (72.6% revisits within an hour), medium-term (12% revisits within a day and 7.8% revisits within a week), and long-term (7.6% revisits longer than a week)
Blending arts and sciences: gimmick or necessity?
The shortage of degree qualified engineers in the UK is well documented. On the other hand the surplus of art and design graduates is growing. Whilst acknowledging the shortage in engineering graduates, there is also the need to recognise the breadth and increased skill level that engineering graduates require. Is it therefore possible to convert some of the excess graduates in art and design to careers in design and development engineering? The success of many engineering businesses depends not only on technical excellence but also on understanding of the market needs and the speed of response to this demand. To make this task even harder, businesses are also expected to compete in markets that are open to global competition and are also faced with much more sophisticated consumers. Businesses that are engaged in the manufacture of goods now require a new breed of engineer. These are not only technically competent individuals, but also possess what is known as âsoftâ or âcreativeâ skills traditionally found in graduates of art and design disciplines. This paper details an innovative curriculum model offered at postgraduate level to address the 21 st century needs of engineering businesses. The paper also details rigorous recruitment tools developed and used for selecting students exclusively from the art and design discipline
Product design as a vehicle to integrate arts and sciences in design education
In many parts of the world, Higher Education has often considered arts and sciences as an odd combination and many institutions have avoided this particular mix. Historically, this has been the accepted view; however, this view is changing. This paper provides a detailed account of curriculum development and strategies for enabling arts and science disciplines to blend in an effective way. It shows how strong alliances can be built in line with industry and general design practice expectations through âLive Projectsâ, that is projects sponsored by industry or other clients. The case studies provided in the paper are based on work conducted in the Product Design and Engineering Department at Middlesex University. The paper further demonstrates the importance of industry involvement, and how industrial collaborations can be managed to ensure that the academic provision is both relevant to the sector as well as responding to the needs of students. The paper was presented at the International Association of Societies of Design Research (IASDR07), held at the Hong Kong Polytechnic University. The papers for the conference were reviewed in a double blind review process, and the conference was attended by an audience of over 400 delegates, focusing on emerging trends in design researc
Public Engagement in the Welsh Parliament
This article provides an analysis of public engagement as it is practised and conceptualised by the Welsh Parliament. It does so by applying an interpretive framework to elite interviews and parliamentary committee report forewords, in order to identify institutional narratives of public engagement. These narratives are identified and discussed at three different levels of decision-making (and in ascending levels of âabstractionâ): practice, strategy, and concept. The chosen framework and methodology show the usefulness of narrative at a conceptual and analytical level. The conclusions drawn â regarding 1) the need for a shift from public-facing to public-engaging committee work, 2) a lack of clarity on desired outcomes, and 3) continued tensions around sources of evidence and knowledge â are relevant and applicable to parliaments across a range of contexts
Including design in e-manufacturing
This paper reviews major issues in the implementation of e-manufacturing, particularly the design aspects. It will examine recent progress, drawing out particular issues that are being addressed. Use will be made of the work by the author and colleagues to devise rule-based design and Internet-based control of machines to illustrate how these developments affect the integrated e-manufacturing environment. A dynamic Simulink model of the way e-manufacture is affected by overall design delays is used to evaluate general solutions for partial and complete e-based companies. These models show how changing to improved designs reduces WI
Muon capture in the front end of the IDS neutrino factory
We discuss the design of the muon capture front end of the neutrino factory
International Design Study. In the front end, a proton bunch on a target
creates secondary pions that drift into a capture transport channel, decaying
into muons. A sequence of rf cavities forms the resulting muon beams into
strings of bunches of differing energies, aligns the bunches to (nearly) equal
central energies, and initiates ionization cooling. The muons are then
accelerated to high energy where their decays provide neutrino beams. For the
International Design Study (IDS), a baseline design must be developed and
optimized for an engineering and cost study. We present a baseline design that
can be used to establish the scope of a future neutrino Factory facility.Comment: 3 pp. 1st International Particle Accelerator Conference: IPAC'10,
23-28 May 2010: Kyoto, Japa
Towards achieving Zero Liquid Discharge in process industry
Fresh water is invaluable in supporting life on Earth. It is scarce, cheap, and exploited. A number of initiatives have been taken to reduce the consumption of fresh water, particularly in agricultural and residential situations. In industry, much focus has been placed on pollution control and wastewater minimisation, however attention to source protection and water minimisation is nominal. The ultimate goal of any water management program is achieving Zero Liquid Discharge (ZLD). This research argues that with a current focus on pollution control and wastewater minimisation, ZLD is not attainable. Protection of water sources has recently been identified as the most critical issue preventing sustainability of industrial water management. It is also given the least attention. This thesis argues that incorporating water auditing and water conservation programs into industrial water management programs is a crucial step towards achieving water source protection and ultimately in achieving zero liquid discharge. A water audit of key water using operations at the BP Refinery in Kwinana has been undertaken to test this hypothesis.
The BP Oil Refinery in Kwinana is an example of an industry which has received much attention for its
excellent practice in water management. BP has almost halved its total water consumption from 7ML/day in 1996 to 4ML/day in 2007. It has developed employee awareness-raising programs, on-site recycling and reuse of wastewater and is now in the final stages of using recycled domestic wastewater as a key water source, expected to minimise fresh water consumption even further.
Despite this, detailed analysis of the major water uses at the refinery show a number of poor management
practices and severe wastages of water. In assessing the whole of refinery water use in Chapter 2, we see that poor record keeping and meter reading is commonplace. Major leaks are left unattended and information about major water-loss incidents is often unavailable. In Chapters 3-5 we look more closely at specific water using operations within the refinery. The refinery steam system is one of the largest fresh water users on site and has been commended for its steam trap survey program and the development of condensate return infrastructure, increasing the percentage of condensate returned from 32% in 1998 to a condensate return target of 50% in 2007. Despite this, major losses still occur in the steam system and turnaround time for fixing major leaks can take years. Simple measures can improve the condensate return rate from 50%-75% quite easily, but there are few incentives for the refinery to invest in such a program which offers diminishing returns. The use of water in process units is enormous, particularly the use of scheme water in the Residue Cracking Unit. A number of available tools and techniques, particularly water pinch and water optimisation tools, are widely recognised to reduce water use on such units but have not been investigated at BP. Many water losses on process units occur because of poor operator management and a focus on increasing efficiency of feed throughput which offers the refinery the greatest financial return. Another inefficient water user in the process category is the Waste Management Area Land Farm. The land farm is irrigated to keep the moisture content of waste high. The exceptionally large volumes of water used in this area can be easily reduced, however costs are considered too high. Finally we assess other uses of water at the refinery. Other uses include commercial and domestic uses, safety showers and the staff carwash. Because of the extraordinary volumes of water used in the refining process, these other uses are considered comparatively insignificant. Practically no water efficiency measures have been taken at this level, and enormous wastages of high quality water are witnessed through our case study of the staff carwash. The carwash is an enormous water waste which uses scheme water once before it is discharged to the sewer.
Each of these case studies shows major inefficiencies in current water management at a number of levels at the BP Refinery in Kwinana. It is important not to forget that this refinery has been recognised for its excellence as a leader in water management not only in the Kwinana Industrial Area but also in the global oil refining industry. This reflects the inherent flaws in water management throughout industry. Chapter 6 assesses management implications associated with reducing water use on site and applies these principles and concepts to industry in general. The most significant barriers to closing industrial water loops were found to be neglect of protection of water sources and larger focus on pollution prevention and wastewater minimisation; misconceptions about the true value of water; and poor regulatory drivers to reduce water use. A paradigm shift in industrial water management to incorporate a more holistic approach is required if water scarcity is to be seriously addressed by industry
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