2,419 research outputs found

    Visualisation and Metering of Two Phase Counter-gravity Slurry Flow using ERT

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    Two-phase slurry flow is encountered in many industries such as petroleum, mining and related industries. The abrasiveness of slurry and interaction of solid particles with the carrier liquid make slurry flow measurement one of the most challenging applications in multi-phase flow metering. This paper presents a new method of solid-liquid flow metering, in which the Electrical Resistance Tomography (ERT) is used in combination with a commercial Electromagnetic Flow Meter (EMF) to measure the volumetric flow rate of each phase. A set of experiments were carried out using a mixture of sand particles and tap water as slurry. Two different sand types (coarse and medium), with a particle size range of 53-2330 μm, were pumped through a 50 mm inner-diameter pipeline. The range of throughput solids concentration used in the experiments was 5%-10% and operated the transport velocity was 2-5 m/s. The effect of solids concentration and solids velocity on the measurement scheme is discussed. The measurement results are compared to that of Coriolis mass flow meter and discharge flow measurement system (flow diversion system). The accuracy of the measurement results is assessed and the performance of the applicability of the proposed method is highlighted

    The Impact of Using Lean-centered Model to Increase the Achievement of the Learners in English Language Teaching

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    The suggested Lean centered-model has been designed to increase the achievement of the students in English Language Teaching (ELT). An experimental study was conducted to find the effectiveness of the model in the application of Lean as an innovative method in English language teaching. The participants of the study scored different achievements in both, the control and treatment groups. The end-result of the learners in the experimental group was statistically highly significant in the pre and posttests. The result was also statistically different between the pre-posttests between the two groups. The current model leads the stakeholders of an educational process to finish the syllabus on time,the program finished as it had been planned and resulting a better achievement. The model was a guide to finish the whole program in line with completing every step before starting the next. The lean-centered model helped to meet the needs of the learners. The learners also managed to get high achievements and develop their skills. The students had their roles as theculture of lean allows learners to be an effective part of the process. All the steps were eliminated which existed in the program and added no value to the end-result of the students according to the lean-centered model

    Electrical Conductivity Based Flow Regime Recognition of Two-phase Flows in Horizontal pipeline

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    An experimental method of resolving flow regimes by utilizing the conductivity data measured by Electrical Resistance Tomography (ERT) is presented. The method applies Boolean logic and frequency analysis of the ERT signal in order to identify five typical flow regimes in horizontal pipe namely: bubble, plug, slug, stratified and annular. The relative conductivity signal obtained from the tomograms is converted to binary form in order to perform Boolean logical operation with the binary templates of typical flow patterns. The overall conductivity of the tomogram is used to extract frequency information of the flow. Flow pattern is identified by the statistical analysis of the combination of this information. The recognition method was evaluated using experimental data from horizontal pipeline for different flow conditions. The identification of the flow regimes from the method was verified using the conductivity images from ERT

    Investigation of the Structural Properties of Thermally Evaporated Aluminium Thin Films on Different Polymer Substrates.

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    This paper studies the properties of thermally evaporated 1 μm of aluminium (Al) thin films on polyimide (PI) and polyethylene terephthalate (PET) substrates at room temperature with thermal evaporation in a vacuum of about 3 x 10-5 Torr for use as window materials for solar cells. Effects of substrate types on the structural and electrical characteristics of the films were studied. Sets of experiments were conducted to optimize the deposition of Al films with appropriate deposition parameters. The deposited films were analyzed with atomic force microscopy (AFM), energy dispersive X-ray (EDX), X-ray diffraction (XRD). Energy dispersive X-ray (EDX) spectra shows presence of Al contacts on both PI and PET substrates. X-ray diffraction (XRD) results illustrate proper formation of Al (111) plane at 38.4o with full width at half maximum (FWHM) of 0.1968° on both samples. Atomic force microscope (AFM) images reveal that both samples possess smooth surfaces with surface roughness root mean square (RMS) below 10 nm

    Proper Orthogonal Decomposition as a technique for identifying multiphase flow regime based on Electrical Impedance Tomography

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    Collecting very large amount of data from experimental measurement is a common practice in almost every scientific domain. There is a great need to have specific techniques capable of extracting synthetic information, which is essential to understand and model the specific phenomena. The Proper Orthogonal Decomposition (POD) is one of the most powerful data-analysis methods for multivariate and nonlinear phenomena. Generally, POD is a procedure that takes a given collection of input experimental or numerical data and creates an orthogonal basis constituted by functions estimated as the solutions of an integral eigenvalue problem known as a Fredholm equation. By utilising POD to identify flow structure in horizontal pipeline, specially, for slag, plug and wavy stratified air-water flow regimes, this paper proposes a novel approach, in which POD technique extends the current evaluation procedure of Electrical Impedance Tomography applied on air-water flow measurement. This extension is provided by implementation of the POD as an identifier of typical horizontal multiphase flow regimes. The POD snapshot matrices are reconstructed for EIT measurement domain and specific flow conditions. Direct POD method introduced by Lumley is applied. It is expected that this study may provide new knowledge on two phase flow dynamics in a horizontal pipeline and supportive information for further prediction of multiphase flow regime

    MAGNETIC HILLS AND OPTICAL ILLUSION IN KURDISTAN REGION

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    “Anti-Gravity Hills", or “Magnetic Hills”, are natural places where apparently defying the law of gravity. In some places in Kurdistan region these magnetic hills exist. This type of hills appears to go uphill is really going downhill. The purpose of the present work was to register an unknown magnetic hill, and a water channel of abnormal apparent direction of flow! And to study what types of physical properties are behind these, we investigated that optical illusion, and a false horizon line are behind

    Numerical modelling of gas-liquid flow phenomena in horizontal pipelines

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    Gas-liquid flows are omnipresent in industrial and environmental processes. Examples are the transportation of petroleum products [1, 2], the cooling of nuclear reactors [3, 4], the operation of absorbers [5], distillation columns [6], gas lift pumps [7] and many mores. Different input parameters induce topologically different flow patterns with different flow character and behaviour [7, 8] . The present study concentrate to diabatic incompressible two-phase flow in horizontal pipeline with separated character [9, 10] (Ugas < 10m/s and Uliquid < 0:2m/s) such as stratified wavy flow regime including typical multiphase instability (Kelvin-elmholtz instability) [11, 12]. The Proper Orthogonal Decomposition (POD) [13], introduced by Lumpay (1967) [14] was used to extract synthetic information essential to understand and to model flow dynamics phenomena. POD in this study are used to identify flow structure in the horizontal pipeline specially under transient of separated flow regimes. The snapshot matrix are reconstruct for specific flow sections and regimes. Present decomposition method, in this case used to analyse CFD data, are originally testing and developing for future using to analyse experimental data obtained by process tomography system [15]

    Triangle of Safety Technique: A New Approach to Laparoscopic Cholecystectomy

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    Backgrounds and Study Aims. Common bile duct (CBD) injury is one of the most serious complications of laparoscopic cholecystectomy (LC). Misidentification of the CBD during dissection of the Calot's triangle can lead to such injuries. The aim of the authors in this study is to present a new safe triangle of dissection. Patients and Method. 501 patients under went LC in the following approach; The cystic artery is identified and mobilized from the gall bladder (GB) medial wall down towards the cystic duct which would simultaneously divide the medial GB peritoneal attachment. This is then followed by dividing the lateral peritoneal attachment. The GB will be unfolded and the borders of the triangle of safety (TST) are achieved: cystic artery medially, cystic duct laterally and the gallbladder wall superiorly. The floor of the triangle is then divided to delineate both cystic duct and artery in an area relatively far from CBD. Results. There were little significant immediate or delayed complications. The mean operating time was 68 minutes, nearly equivalent to the conventional method. Conclusions. Dissection at TST appears to be a safe procedure which clearly demonstrates the cystic duct and may help to reduce the CBD injuries

    Make way for the algorithms: symbolic actions and change in a regime of knowing

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    When actors deem technological change undesirable, they may act symbolically by pretending to comply while avoiding real change. In our study of the introduction of an algorithmic technology in a sales organization, we found that such symbolic conformity led unintendedly to the full implementation of the suggested technological change. To explain this surprising outcome we advance a regime-of-knowing lens that helps to analyze deep challenges happening ‘under the surface’ during the process of technology introduction. A regime of knowing guides what is worth knowing, what actions matter to acquire this knowledge, and who has the authority to make decisions around those issues. We found that both the technologists who introduced the algorithmic technology, as well as the incumbent workers whose work was affected by the change, used symbolic actions to either defend the established regime of knowing or to advocate a radical change. While the incumbent workers enacted symbolic conformity by pretending to comply with suggested changes, the technologists performed symbolic advocacy by presenting a positive side of the technological change. Ironically, because the symbolic conformity enabled and was reinforced by symbolic advocacy, reinforcing cycles of symbolic actions yielded a radical change in the sales' regime of knowing: from one focused on a deep understanding of customers via personal contact and strong relationships, to one based upon model predictions from the processing of large datasets. We discuss the theoretical implications of these findings for the introduction of technology at work and for knowing in the workplace.Cambridge Judge Business School internal gran
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