9,229 research outputs found

    Development of multidimensional fluorescence imaging technology with a view towards the imaging of signalling at the immunological synapse

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    This thesis describes the development and application of multidimensional fluorescence imaging to signalling events at the Natural Killer cell immunological synapse. The primary techniques used in this work are intensity imaging, ratiometric spectral fluorescence imaging and fluorescence lifetime imaging, which have been applied to live and fixed cells. It is shown that although protein accumulation at the immunological synapse can simply be determined by intensity imaging, the presence of protein does not indicate that signalling events are occuring. Signalling at the inhibitory synapse as determined by KIR2DL1 receptor phosphorylation is imaged by means of confocal FLIM. The resolution achievable using this technique is then improved upon by the use of optical tweezers for cell reorientation. A comparison of the sectioning abilities of single point confocal and multiphoton microscopy with multipoint spinning disk based systems is made and a means of achieving an increased rate of imaging for the gold standard of FLIM methods, TCSPC FLIM, is proposed. The proposed multifocal multiphoton TCSPC FLIM system is first simulated and then implemented, with a comparison to widefield time-gated FLIM being carried out. The system is then used to image test samples, and to acquire cell-level metabolic information with the highest time resolution achieved to date via autofluorescence imaging of NADH. Membrane order at activating and inhibitory NK cell immunological synapses is examined by means of ratiometric imaging of a lipid phase-sensitive dye, and software is developed for the analysis of NK cell spreading patterns, and this software was used to demonstrate that the spreading behaviour of NK cells is affected by the type ofligands encountered in terms of the symmetry and dynamics of spreading

    Experimental Research Work to Optimize Process Parameters into Electro Chemical Abrasive Flow Machining using Taguchi Methodology

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    Electrochemical assisted abrasive flow finishing is a newly developed hybrid finishing process which is used to finish the internal parts of work piece having complicated geometry to large extent. In electrochemical assisted abrasive flow machining higher abrasion of the material was detected due to the combine effect of ECM and AFF processes. In Electrochemical aided abrasive flow machining a electrolyte is added to the prepared media .This media consist a kind of polymeric carrier and abrasive particles that are hydrocarbon gel, Al2O3, Silicon based polymer, and NaI Sodium iodide as electrolytic salt. In this experimental research different process parameters such as voltage, abrasive concentration, Number of cycle, molal concentration and diameter of rod were considered at different levels for response characteristic of surface roughness Ra and material removal MR based on Taguchi method using standard L27 orthogonal array OA for the plan of experimentation. To determine the contribution of each parameter analysis of variance was used. Sandeep Singh | Sunil kumar "Experimental Research Work to Optimize Process Parameters into Electro Chemical Abrasive Flow Machining using Taguchi Methodology" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-4 , June 201

    Heavy traffic analysis of open processing networks with complete resource pooling: asymptotic optimality of discrete review policies

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    We consider a class of open stochastic processing networks, with feedback routing and overlapping server capabilities, in heavy traffic. The networks we consider satisfy the so-called complete resource pooling condition and therefore have one-dimensional approximating Brownian control problems. We propose a simple discrete review policy for controlling such networks. Assuming 2+\epsilon moments on the interarrival times and processing times, we provide a conceptually simple proof of asymptotic optimality of the proposed policy.Comment: Published at http://dx.doi.org/10.1214/105051604000000495 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Organizational Decline andTurnaround Management: Empirical Study of a Government Owned AutomobileCompany

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    Performance of an organization is an outcome of its series of action choices in response to the changes in business environment or independently. Such choices are influenced by the leadership characteristics, organizational characteristics and perceived munificence of the environment. Strategic actions such as location of plant, selection of CEO, product-market domain initiatives, expansion, thrust on quality and quantity influence the long term survivability of companies. The paper examines the linkage of action choices with macro organizational variables during decline and turnaround phase of an automobile company.

    Experimental research to Optimize Process Parameters in Machining of Non Conducting Material with hybrid non conconventional machining

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    Among all non conventional micro machining, electrochemical discharge machining ECDM is having high quality of material removal rate with zero residual stress. This machining has been accepted as a highly modern technology in micromachining. In this paper an effort has been done on micro drilling of glass using electrochemical discharge machining ECDM . A fixed tool and a step down transformer have been used to support the steady machining to increase the accuracy of work piece. The input parameters used in this experiment are voltage, concentration of electrolyte, enter electrode gap and ratio of area of electrode. MRR has been investigated over the input parameters. Feed rate and electrolyte temperature has been made constant of 3µm sec and 30°c respectively. Taguchi method is used to optimize the effect of the process parameters on MRR. The signal to noise S N ratio and the ANOVA analysis are employed to find the contributions of input parameters. Vikrant Sharma | Sunil Kumar "Experimental research to Optimize Process Parameters in Machining of Non Conducting Material with hybrid non conconventional machining" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-4 , June 201
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