3,429 research outputs found
Mini-loop ligation of a bleeding duodenal Dieulafoy's lesion
No full textTwo percent of gastrointestinal hemorrhages are caused by Dieulafoy's lesions, which are located in duodenum in only 15% of cases. There are no recommendations regarding the prime endoscopic treatment technique for this condition. A 61-year-old woman presented with melena without signs of hemodynamic instability. During an urgent upper endoscopy, blood oozing from the normal mucosa of the duodenum was seen and this was classified as a Dieulafoy's lesion. A mini-loop was opened at the rim of a transparent ligation chamber, at the end of the endoscope, and after aspiration of the lesion, closed and detached. Complete hemostasis was achieved without early or postponed complications. In every day clinical practice, mini-loop ligation is rarely used because of possible complications, such as site ulceration, organ perforation, re-bleeding and possible inexperience of the operator. To the best of our knowledge this is the first case of successful treatment of bleeding duodenal Dieulafoy's lesion by mini-loop ligation
Mini Cooper 1961-2000
No full textFrom its launch on 20 September 1961 the Mini Cooper caused a sensation. The world’s first sports saloon, the diminutive Cooper combined the glamour and racing heritage of 1959 and 1960 Formula 1 champions the Cooper Car Company with the outstanding handling and downright practicability of the Austin Mini Seven and Morris Mini Minor. Alec Issigonis’s little people’s car had been launched by the manufacturer, the British Motor Corporation (BMC), two years earlier. A winner almost from the word go, the Mini Cooper not only ruled the racetracks and rally stages of the early and mid-1960s but proved to be a practical and fun sporting family saloon car. After over 100,000 examples were sold between 1961 and 1971, the Mini Cooper is still a practical sporting saloon in the guise of the BMW-owned MINI Cooper sixty years after the introduction of the original model.This remarkable product of the United Kingdom merits a fresh examination as it nears its sixtieth birthday. Based upon over fifty face-to-face interviews carried out by the author over more than a decade, this book quotes the Mini Cooper’s designers, developers, and professional race and rally drivers plus a host of contemporary owners. Here then in the words of its originators, is the story of the Mini Cooper
Self-Assembly of Ion-Containing Block Copolymers with Tailored Ion Transport Properties
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Parametric investigation\of mini-tab for load alleviation
No full textThis thesis investigates a novel load alleviation technique known as mini-tabs, small devices placed on the upper surface of wings to reduce lift. Reynolds-Averaged Navier-Stokes (RANS) simulations were conducted to analyze the impact of geometrical properties on mini-tab performance in reducing the load on a wing.The initial simulations focused on a single mini-tab, varying parameters such as height, aspect ratio, chordwise, and spanwise positions. Results indicate that increasing height or aspect ratio leads to decreased lift due to flow deceleration at the leading edge and expansion of the separated flow region downstream of the mini-tab. This will also increase the pressure drag. Increasing the height or aspect ratio also accelerates the flow at the lower surface, further reducing the lift generated by the wing.Placing mini-tabs closer to the wingtip exhibits similar effects on lift reduction as increasing the height of the mini-tabs. This is because the relative height of the mini-tab with the local chord length increases when the mini-tab is positioned closer to the wingtip. A maximum lift reduction is also achieved when the mini-tab is placed at a 60% chordwise position.Subsequent simulations explored the performance of multiple mini-tabs, revealing that orienting them orthogonal to the wind direction may not be optimal due to gap formation between the mini-tabs that energizes the wake downstream of the mini-tabs and reduces the reduction in lift. Conversely, aligning the mini-tabs with the leading edge has a higher efficiency in the reduction of the lift.Overall, the findings suggest that mini-tabs offer a viable method for reducing wing forces and for load alleviationAerospace Engineerin
Mini-Trials in Alberta
No full textThe Alberta Court of Queen\u27s Bench has been offering the mini-trial, a specialized dispute resolution process, to litigants and the bar for the last four years. The impetus for this move was the length and time often involved in litigation. The attraction of the mini-trial is that it is a method of expediting dispute resolution and that the costs associated with it are considerably less than those for a regular trial.
The author outlines the history of the mini-trial, explaining how it developed in the U.S. as a private dispute resolution mechanism. The Alberta mini-trial is essentially an expanded pre-trial procedure, and is offered by the Court at no cost to participants. There is no rigid, formal procedure to the Alberta mini-trial, and its great strength is in fact flexibility and informality. The only requirement the Court has is that the actual parties must be present for the arguments and at the end of the mini-trial, when the judge gives his or her opinion.
The author outlines the key elements of the mini-trial, as they have evolved to date, including the role of the judge and the nature of the actual process.
The mini-trial has been enormously successful at encouraging settlements, which have followed or resulted from the mini-trial in over 90 percent of cases. Additionally, both counsel and clients appear to be quite pleased with the process. Despite this success, however, it should be noted that the mini-trial may not be appropriate in all cases. The author describes the types of cases to which the mini-trial both is and is not well-suited. He offers a case study, of a mini-trial over which he presided. This mini-trial was successful and led to a settlement. In closing, the author provides information to interested counsel and parties as to how and when they can access the mini-trial. The article closes with a recommendation that mini-trials always be considered as an option in lawsuits
Novel Simulator for Wireline Mini-Fracture Testing
No full textWireline Mini-Fracture testing jobs consist of a short duration, small volume fracturing operation inside an open-hole borehole, where a certain amount of fluid is injected into the formation at constant rate using a Wireline Modular conveyed tool as a source of hydraulic power to pressurize the wellbore. The tool is configured with an inflatable straddle packer and an internal pump, which inflate/deflates the packers and supplies pressure to the formation until a hydraulic fracture is induced. This procedure is used to determine in–situ formation breakdown and closure pressure also known as minimum horizontal closure pressure. This provides vital information regarding hydraulic fracture design, water and gas injection management, fault re-activation, wellbore stability, sand production, rock mechanical properties, casing string design, cap and base rock integrity and gas storage design. Geomechanical and operational parameters such as, elastic properties, poro-elasticity, rock strength, formation pore pressure, far field horizontal stress, permeability/porosity distributions, borehole fluid properties among others, influences the performance of the Mini-Frac Jobs. In many cases poor understanding of the reservoir response to the fracture process, caused that the hydraulic fracture did not propagate deep into the formation. In other cases the pressure applied to the formation might be insufficient to break down the formation, leading to unsatisfactory application of the Mini-Fracture technique in the process. The objective of this thesis is to develop a Mini-Facture application simulator that uses the geomechanical and operational parameters that control the performance of a Mini-Fracture job and estimate the possibility of the occurrence of a tensile failure in the formation. The simulator is then validated by comparing its output with the results of stress test done in the field. With this simulator petrotechnical professionals and field engineers will have a platform that simulates the pressure responses and fracture initialization during Mini-Frac treatments, incorporating all the variables affecting a Wireline Mini-Fracture job, helping the design engineer to make key decisions about the ultimate or required fracture plan. Furthermore the simulator will reduce the uncertainties that limit the reliability of the Wireline Mini-Fracture treatment by allowing the selection of appropriate tool configuration based on the job objectives and the geological environmental conditions. Finally this project demonstrates that combining the appropriate constitutive relations that reflect the coupling among the tool operational performance with wellbore flow, reservoir and geomechanics modelling a Mini-Fracture simulator can be developed.Petroleum EngineeringGeoscience & EngineeringCivil Engineering and Geoscience
Flow boiling of R134a in vertical mini-diameter tubes
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 21/03/2011.The current study is a part of a long term experimental project devoted to investigate flow boiling heat transfer, pressure drop and flow visualization of R134a in small to mini/micro-diameter tubes. The experimental facility was first designed and constructed by X. Huo (2005) with the contribution of L. Chen (2006). In the present study, the experimental facility was upgraded by changing the heating system from AC to DC heating and also upgrading the logging system through using a faster data logger and developing a new Labview program. The objectives of the current study include (i) contribute in identifying the reasons behind the wide scatter in the published flow boiling heat transfer results, (ii) contribute in understanding the fundamentals of flow boiling heat transfer in mini/micro-diameter tubes and (iii) evaluation of the existing heat transfer and pressure drop prediction methods. Two sizes of stainless steel tubes were investigated in the current study; 0.52 mm and 1.1 mm diameter. In the current study, the 0.52 mm tube was roughly called a “micro-tube” whilst the 1.1 mm tubes were called “mini-tubes”.
The present study proposes two possible reasons for the scatter in the published heat transfer results. The first reason is the variations in the heated length from one study to another–there is no criterion for choosing the heated length. The second reason is the variations in the inner surface characteristics of the channels from one study to another. These two important parameters were not taken into consideration by researchers in the past studies. Accordingly, the effect of the heated length was investigated in the current study using a seamless cold drawn tube with diameter of 1.1 mm and heated length ranging from 150 to 450 mm. The effect of the tube inner surface was also tested here by conducting the test in two stainless steel tubes with diameter of 1.1 mm and manufactured by two different processes. The first tube was manufactured by welding technique whilst the second tube was a seamless cold drawn tube. Both tubes were identical in design and dimensions. The inner surface of each tube was examined first using SEM analysis and demonstrated that, the surface morphology is completely different. The local heat transfer coefficient was determined through measuring the local wall temperature using 14 K-type thermocouples attached to the wall using thermally conducting but electrically insulating epoxy supplied by Omega. Pressure drop was measured directly across the heated section and a high speed camera was used for the flow visualization at 1000 frames/s. All measurements were recorded after the system attained steady state. The experimental conditions include mass flux range of 100 – 500 kg/m2 s, system pressure range of 6 – 10 bar, inlet sub-cooling of about 5K and exit quality up to about 0.9.
The most frequently observed flow regimes in the 0.52 mm tube were found to be slug (elongated bubble), transition to annular and annular flow regimes. In the 1.1 mm tube, the observed regimes were found to be slug, churn and annular. The transition from slug flow to annular flow in the 0.52 mm tube occurred smoothly with little disturbances at the liquid vapour interface compared to the 1.1 mm tube. Additionally, increasing the heated length of the 1.1 mm tube was found to shift the transition to annular flow to occur at lower vapour quality.
The heat transfer results demonstrated that the behaviour of the local heat transfer coefficient in the 0.52 mm diameter tube is different compared to that in the 1.1 mm tubes. Also, the tube inner surface characteristics and the heated length were found to strongly influence the local behaviour of the heat transfer coefficient. Flow boiling hysteresis was investigated and the results indicated that hysteresis exists only at very low heat fluxes near the boiling incipience.
Existing heat transfer and pressure drop correlations were examined using the results of the 0.52 and 1.1 mm seamless cold drawn tubes. The pressure drop data were predicted very well using the Muller-Stienhagen and Heck (1986) correlation, the homogeneous flow model and the correlation of Mishima and Hibiki (1996). On the contrary, all macro and microscale heat correlations failed to predict the current experimental data. The mechanistic models failed to predict the data of all tubes with the same accuracy. Accordingly, two heat transfer correlations were proposed in the current study. The first correlation is based on dimensionless groups whilst the second is based on the superposition model of Chen (1966). Both correlations predicted the current experimental data and the data of Huo (2005) and Shiferaw (2008) very well.Egyptian Ministry of Higher Educatio
Twirre: Architecture for autonomous mini-UAVs using interchangeable commodity components
No full textTwirre is a new architecture for mini-UAV platforms designed for autonomous flight in both GPS-enabled and GPS-deprived applications. The architecture consists of low-cost hardware and software components. High-level control software enables autonomous operation. Exchanging or upgrading hardware components is straightforward and the architecture is an excellent starting point for building low-cost autonomous mini-UAVs for a variety of applications. Experiments with an implementation of the architecture are in development, and preliminary results demonstrate accurate indoor navigation
Mini-India
No full textChapter 4 highlights how, as a consequence of migration and place-making processes, the discourses of locality, nation, and community came to be equated with the term ‘Mini-India’. Here, three intersecting meanings of the notion of Mini-India are discussed: The first section describes how the term ‘Mini-India’ is appropriated by the state to encompass diverse ethnic and religious identifications under the nationalist slogan ‘unity in diversity’ and to declare the pluralist Andaman society as a secular example of communal harmony. The second part considers Mini-India as a subaltern consciousness, which the author calls the ‘island mentality’. From this perspective, Mini-India refers to a localized sense of belonging that can also be termed a ‘rural cosmopolitanism’. Thirdly, it is argued that the notion of Mini-India must, at the same time, be regarded as an arena of politics in which ethnic communities compete with each other for funds and recognition by the state.</p
An investigation into the methodology of mini-bus taxi data collection as part of the current public transport record : a case study of Stellenbosch in the Western Cape
No full textIncludes summary.Includes bibliographical references (leaves 80-82).The Cape Winelands District Municipality in Stellenbosch, Cape Town, commissioned Pendulum Consulting to undertake a planning study for a public transport tourism service in their area. The project entails the preparation of a Business Plan to incorporate the existing taxi industry in Stellenbosch in providing tourism transport, as part of their current services. In order to plan this service, it was necessary to have accurate information on the current public transport services in the town, such as passenger demands, minibus taxi routes and other operational data. It was, initially, envisioned that the base data from the existing 'Current Public Transport Record' (CPTR) could be utilised to prepare the business plan for this new service, but after reviewing the most recent CPTR, it was observed that it provided insufficient information regarding the en-route passenger and operational data of the minibus taxi industry. Hence, the shortcomings of the CPTR let to the motivation in conducting the on-board taxi surveys on the majority of the minibus taxi services in the Stellenbosch area. The author was responsible for liaising with the taxi industry, planning and overseeing the on-board survey, as well as the data capturing and analysis of the raw survey data, as part of the tourism project
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