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Performance Improvement of ED at VGH Using Simulation and OptimizationZhao, Yuancheng 15 September 2013 (has links)
Emergency department(ED) is one of the busiest clinical units in Winnipeg Victoria Gen-eral Hospital (VGH) which faces the challenge of patients’ long waiting-time as increas-ing healthcare demand and limited resources. This research investigates the critical factors of the ED operation to enhance the operational efficiency using simulation modeling and optimization. The contribution of this research is the integration of simulation and optimization for the performance improvement of ED operations. Discrete-events simula-tion (DES) methodology provides a cost-effective tool to analyse the performance of the ED operations and evaluates the potential alternatives. Design of experiments (DOE) and Scatter search (SS) of model optimization are proposed to search the ED potential capaci-ty for waiting-time reduction. The patient-flow is accelerated along with the waiting-time reduction, which results in better efficient patient throughput in the ED. A specific strate-gy is suggested to improve the ED operation based on the simulation model.
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Analytical models for calculating the response of temporary soil-filled walls subjected to blast loadingScherbatiuk, Kevin Daniel 13 January 2010 (has links)
The aims of the thesis were to study the response of temporary soil-filled walls both experimentally and numerically, and to develop an efficient and accurate analytical model to predict 2-D planar response from blast loading which could be used to efficiently calculate a pressure-impulse (P-I) curve. An explicit finite element (FE) formulation was constructed using LS-Dyna software, and two analytical models were also derived and presented: a Rigid-Body Rotation model as a preliminary model, and the Rigid-Body Hybrid model as the proposed model of this thesis. Seven full-scale experiments which consisted of blast loading simple free-standing soil-filled Hesco Bastion (HB) walls are presented.
Apart from comparison of an experimental result where the soil-fill in the wall possessed sizable cohesion, the response of the Rigid-Body Hybrid model was in very good agreement with the experiments overall (within 10 %). A soil sensitivity study was conducted and overall very good agreement was reached between the Rigid-Body Hybrid model in comparison with the FE model in its ability to capture differences in displacement-time histories from differences in soil parameters. Comparison with the FE model for different height-to-width ratios of walls showed that the Rigid-Body Hybrid model was within 10 % for all rotation angles and predictions of critical overturning impulse for height-to-width ratios of walls . P-I curves were developed using the analytical and FE models for the three different wall configurations studied in the experiments. The results demonstrated that the proposed Rigid-Body Hybrid model is useful for calculating a P-I curve for a HB wall efficiently and yielded very accurate results (within 5 % for the impulse asymptotes).
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On the statistical analysis of functional data arising from designed experimentsSirski, Monica 10 April 2012 (has links)
We investigate various methods for testing whether two groups of curves are statistically significantly different, with the motivation to apply the techniques to the
analysis of data arising from designed experiments. We propose a set of tests based on pairwise differences between individual curves. Our objective is to compare the power and robustness of a variety of tests, including a collection of permutation tests, a test based on the functional principal components scores, the adaptive Neyman test and the functional F test. We illustrate the application of these tests in the context of a designed 2^4 factorial experiment with a case study using data provided by NASA. We apply the methods for comparing curves to this factorial data by dividing the data into two groups by each effect (A, B, . . . , ABCD) in turn. We carry out a large simulation study investigating the power of the tests in detecting contamination, location, and shift effects on unimodal and monotone curves. We conclude that the permutation test using the mean of the pairwise differences in L1 norm has the best overall power performance and is a robust test statistic applicable in a wide variety of situations. The advantage of using a permutation test is that it is an exact, distribution-free test that performs well overall when applied to functional data. This test may be extended to more than two groups by constructing test statistics based on averages of pairwise differences between curves from the different groups and, as such, is an important building-block for larger experiments and more complex designs.
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Quantification of Damage in Selected Rocks due to Impact with Tungsten Carbide BitsNariseti, Chanakya 05 December 2013 (has links)
Impact induced dynamic cracks are produced with a Split Hopkinson Pressure Bar (SHPB) apparatus in two rocks (Kuru granite and Flamboro limestone) with impact velocities ranging from 8 to 12 m/s. Impact bit (tungsten carbide) diameters range from 8mm to 15mm. Dye impregnation combined with UV imaging, CAT scans and Optical scans were employed to study the resulting crack patterns. The resulting damage is quantified in terms of radial crack density on impact surface, crater, crushed zone and crack density with depth. In both rocks ‘total’ damage obtained is directly proportional (exponential) with bit diameter and impact velocity. The ‘total’ damage in Kuru granite is found to be greater than Flamboro limestone at all impact velocities; however, the crushed zone in the latter is found to consistently greater than the former. 2D simulations of dynamic fractures with AUTODYN have also been carried out showing good qualitative agreement with experimental results.
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In vivo cell tracking with 52Mn PET: Targetry, Separation, and ApplicationsGraves, S., Lewis, C., Valdovinos, H., Bednarz, B., Cai, W., Barnhart, T., Nickles, R. 19 May 2015 (has links) (PDF)
Introduction
52Mn (t½ =5.59 d, β+ = 29.6%, Eβmax = 0.58 MeV) has great potential as a long lived PET isotope for use in cell tracking studies, observation of immunologic response to disease states, or as an alternative to manganese-based MRI contrast agents. Its favorable max positron energy leads to superb imaging resolution, comparable to that of 18F.[1]
Manganese is naturally taken up by cells via a multitude of pathways including the divalent metal transporter (DMT1), ZIP8, transferrin receptors (TfR), store-operated Ca2+ channels (SOC-Ca2+), and ionotropic glutamate receptor Ca2+ channels (GluR).[2] These natural transport mechanisms make 52Mn an attractive isotope for applications necessitating non-perturbative cell uptake. In particular, cell tracking is critical to the development and translation of stem cell therapies in regenerative medicine. Alternative-ly, 52Mn could be used in immunotherapy techniques such as adoptive cellular therapy (ACT) to evaluate the ability of external immune cells to reach their intended target.
Material and Methods
52Mn was produced by natCr(p,x)52Mn using 16 MeV protons. The average thick target production yield was 0.23 mCi/µA-h with less than 0.25% co-production of 54Mn. Small amounts of 51Cr were observed in the target, but were absent from the radiochemically separated product.
Target construction consisted of a water jet cooled chromium disc (3/4” diameter, 0.4” thick). Targets were purchased from Kamis Inc, and are 99.95% pure. Targets withstood beam currents of 30 µA with no visible aberration.
Chromium targets were etched by concentrated HCl following bombardment. Mn2+ ions were extracted from 9M HCl to 0.8M trioctylamine in cyclohexane leaving the bulk chromium in the aqueous phase. After isolating the organic phase, 0.001M NH4OH was used to back-extract the Mn2+ ions to aqueous phase. This purification cycle was conducted a total of three times for each 52Mn production.
Results and Conclusion
For a starting bulk chromium mass of 456 ± 1 mg, a post-separation chromium mass of 5.35 ± 0.04 ng was measured by microwave plasma atomic emission spectrometry (MP-AES). This mass reduction corresponds to an average separation factor of 440 for a single purification cycle. Each purification cycle had a 52Mn recovery efficiency of 73 ± 7 % (n = 6), resulting in an overall separation efficiency of approximately 35 %. These efficiencies and separation factors agree reasonably well with the work conducted by Lahiri et. al.[3] Prior to use, the product was passed through a C-18 Sep-Pak to remove any residual organic phase.
After four target irradiations and etchings, some pitting became noticeable on the target face. These have not yet compromised the o-ring seal with the target deplater, but it is possible that target replacement after every 6–9 52Mn productions will be necessary moving forward.
Following the successful separation of 52Mn from chromium, in vitro experiments were conducted to demonstrate the uptake of 52Mn by human stem cells and mouse tumor cells. A linear uptake response was observed as a function of the amount of activity exposed to the cells for both cell models. These experiments have shown great promise for 52Mn as a long-lived PET isotope in cell tracking studies. Details will be presented.
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Transport and metabolism of 8(14C)t-Zeatin.Hutton, Margaret Joan. January 1982 (has links)
A review of the literature established that there were
areas of cytokinin transport which needed further investigation,
in order to determine the function and/or
mode of action of cytokinins during certain stages of
plant development. Radioactive zeatin was applied to
plant systems suitable for determining more about specific
problems of cytokinin transport. The metabolism of the
radioactive zeatin was monitored in relation to transport.
The metabolism in, and possible export of, radioactive
zeatin out of immature, mature and senescing Ginkgo biloba
leaves was monitored using explants. The results showed
that approximately the same percentage radioactivity was
exported from the leaves at all three stages of their development.
This indicates that these deciduous leaves
could potentially export cytokinins, but the results were
not regarded as being significant. Cytokinins would not
have been expected to be transported out of expanding
leaves, which rapidly utilize cytokinins, and in comparison
greater cytokinin export would have been expected to occur
from senescing leaves, but this did not occur. The resuIts
could indicate that cytokinin glucosides in deciduous
leaves are primarily inactivation products rather than
storage compounds.
The metabolism and transport of radioactive zeatin, applied
to the leaves of Citrus sinesis trees, was monitored during the flush of new growth following a dormant period.
Some of the radioactive zeatin applied to these leaves
appeared to be utilized in the new shoot growth. This
could imply that accumulated cytokinin glucosides in these
evergreen leaves are exported out of the leaves and reutilized,
and thus fulfil a storage function; although
the extent to which export occurred as opposed to interconversion
and/or catabolic metabolism in the leaves could
not be determined.
The distribution of radioactive zeatin applied to the
xylem and phloem of Phaseolus vulgaris plants at three
stages of development was also monitored. There appeared
to be preferential transport of cytokinins in the transpiration
stream, that is, applied to the xylem. The
vegetative apices, buds and flowers appeared to be the
major sinks for radioactive compounds in the vegetative
and flowering plants, and the leaves were the most important
sink in the fruiting plants. Radioactive zeatin
in the phloem appeared to move passively with the assimilate
stream. The transport of radioactive zeatin applied to
the primary leaves appeared to confirm that cytokinins in
the phloem were transported along with the assimilate
stream. The results also indicated that the accumulated
cytokinin glucosides in these annual leaves were primarily
inactivation products, involved in regulating leaf
metabolism, although some re-utilization of these cytokinins
could potentially take place. could have reflected normal cytokinin transport occurring
in the tissues. The main metabolic pathway, oxidation,
did not, however, appear to be the main metabolic pathway
in the plant tissues and may have been the result of the
exogenous application of zeatin. The fact that metabolism
did not appear to be the normal metabolism of the
tissues, could potentially have affected transport. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1982.
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Performance Improvement of ED at VGH Using Simulation and OptimizationZhao, Yuancheng 15 September 2013 (has links)
Emergency department(ED) is one of the busiest clinical units in Winnipeg Victoria Gen-eral Hospital (VGH) which faces the challenge of patients’ long waiting-time as increas-ing healthcare demand and limited resources. This research investigates the critical factors of the ED operation to enhance the operational efficiency using simulation modeling and optimization. The contribution of this research is the integration of simulation and optimization for the performance improvement of ED operations. Discrete-events simula-tion (DES) methodology provides a cost-effective tool to analyse the performance of the ED operations and evaluates the potential alternatives. Design of experiments (DOE) and Scatter search (SS) of model optimization are proposed to search the ED potential capaci-ty for waiting-time reduction. The patient-flow is accelerated along with the waiting-time reduction, which results in better efficient patient throughput in the ED. A specific strate-gy is suggested to improve the ED operation based on the simulation model.
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Essays on Development and Behavior Economics: An Impact Evaluation of the “Bolsa Família” - Conditional Cash Transfer on Education and the Effect of Leadership Identity on Group Cooperation and Elite CaptureSchaffland, Elke 18 June 2013 (has links)
No description available.
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Habits and Habitats : Crafting Through a Prism of Culture ShockButucariu, Diana January 2014 (has links)
This is a text about a work of art, “The Room”, and about the process that brought it about. The process includes experiments in clay bodies, mixing different elements with the base clay in search of a material both suitable to work with in terms of texture and color, but also rich in less tangible qualities, as I mix in elements which carry a set of values of cultural identity. The text follows the path towards development of the final piece during the two-year course of the master program at Konstfack. During these two years, external factors such as dealing with the issues of culture shock, and searching for a place to live, interfere with my way of thinking, leading to unexpected turns in the direction of my artistic process. Searching for an apartment finds me standing in strangers' apartments as they sell their homes, their ways of life and their house rules. These sometimes awkward meetings provide a good starting point in my research of people's habits and habitats. In trying to understand some elements of Swedish culture, I become aware of the fact of my own culture and start thinking about it from an outside perspective. Eventually, the central question of the essay crystallizes: Who will carry on the traditional craft techniques of my home country? Romania is the rare place in Europe where crafts are still being practiced as they have been for hundreds of years, in the villages by crafts persons leading traditional lives. As the villages are emptied of young people, moving into cities, and as Romania as a whole is drained of a large part of its young and ambitious generation, moving to other European countries for jobs and education, a trend that I am of course part of, the traditions that I have taken for granted, growing up with my grandmother in a traditional village, become threatened. The answer to the question is a simple as it is demanding: I have to be part of the future of Romanian crafts. To document them, understand them, and incorporate them in my art. For this purpose, I undertake an investigative research trip. The text presents my findings about the crafts, and about the people working to document and preserve the traditions. The research trip is also presented in the movie “Six days in Romania”, which I include as an appendix to the essay. Over the course of two years, several short-term art projects have been completed within the master program. They are presented in the form of an interview with myself. Looking back at these projects, they become explained as necessary steps in preparation for the final piece, a viewpoint very different from the utter confusion that was the dominating feeling of at least the first year of the course. The interview tries to give insight into the non-linear process that is the creative work. Finally, in a poetic description of the final piece, I let my art speak for itself in a very literal way. In giving voice to the piece, I try to access truths hidden even to myself, in an effort to be as transparent as possible about the value of my efforts.
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Analytical models for calculating the response of temporary soil-filled walls subjected to blast loadingScherbatiuk, Kevin Daniel 13 January 2010 (has links)
The aims of the thesis were to study the response of temporary soil-filled walls both experimentally and numerically, and to develop an efficient and accurate analytical model to predict 2-D planar response from blast loading which could be used to efficiently calculate a pressure-impulse (P-I) curve. An explicit finite element (FE) formulation was constructed using LS-Dyna software, and two analytical models were also derived and presented: a Rigid-Body Rotation model as a preliminary model, and the Rigid-Body Hybrid model as the proposed model of this thesis. Seven full-scale experiments which consisted of blast loading simple free-standing soil-filled Hesco Bastion (HB) walls are presented.
Apart from comparison of an experimental result where the soil-fill in the wall possessed sizable cohesion, the response of the Rigid-Body Hybrid model was in very good agreement with the experiments overall (within 10 %). A soil sensitivity study was conducted and overall very good agreement was reached between the Rigid-Body Hybrid model in comparison with the FE model in its ability to capture differences in displacement-time histories from differences in soil parameters. Comparison with the FE model for different height-to-width ratios of walls showed that the Rigid-Body Hybrid model was within 10 % for all rotation angles and predictions of critical overturning impulse for height-to-width ratios of walls . P-I curves were developed using the analytical and FE models for the three different wall configurations studied in the experiments. The results demonstrated that the proposed Rigid-Body Hybrid model is useful for calculating a P-I curve for a HB wall efficiently and yielded very accurate results (within 5 % for the impulse asymptotes).
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