The project is a research on liquid methane. It is stored in a standing and static pressure vessel specially calculated for cryogenic purposes. All the simulations have been done using the finite element method.  The  finite  element  method  (FEM)  or  finite  element  analysis  (FEA)  is  a  numerical technique to find approximate solutions for partial differential equations and it is used to simulate the strength of materials. FEM allows the user to visualize the distribution of stresses and displacements. There is a wide range of software to do FEM simulations, the software chosen for the project is Pro/Engineer Wildfire 4.0.  Pro-Engineer  is  a  CAD/CAM/CAE  software  developed  by  Parametric  Technology Corporation (PTC).  It provides solid modeling, assembly modeling and finite element analysis.  The  results  obtained  in  the  mechanical  analysis  executed  with  the  application  Pro-mechanica show that the designed container holds the loads applied and stands stable.  The thermal analysis of the insulation verifies that the amount of heat exchanged with the environment is on acceptable levels. Finally, to protect the integrity of the structure the proper paints have been selected.

Blood is a dense suspension of flexible red blood cells. In response to a background flow, these cells distribute themselves non-uniformly throughout the vessel. As a result, material properties that are well defined in homogeneous fluids, such as viscosity, are no longer so, and depend upon the flow geometry along with the particle properties. Using a simple model that accounts for the steady-state particle distribution in vessel flow, we derive an expression for the effective viscosity of blood and the suspension flow velocity field in a pressure-driven tube flow. <br /><br /> We derive the steady-state particle distribution from a conservation equation with convective flux arising from particle deformation in the flow. We then relate the particle microstructure to the overall flow through a generalized Newtonian stress-tensor, with the particle volume fraction appearing in the expression for the local viscosity. Comparing with experimental data, we show that the model quantitatively reproduces the observed rheology of blood in tube flow. <br /><br /> We reconsider the problem in an alternate geometry corresponding to the flow between two concentric cylinders. The steady-state particle distribution, suspension velocity field and the measured effective viscosity are all very different from their counterparts in tube flow, casting serious doubt upon the practice of using data from a Couette viscometer to parameterize constitutive models applied to vascular blood flow. <br /><br /> Finally, we calculate the effect of random fluctuations in the particle velocity on the averaged behaviour of the particle conservation equation. Using a smoothing method for linear stochastic differential equations, we derive a correction to the free Einstein-Stokes diffusion coeffcient that is due to the interaction of the particles with their neighbours.

Fluidized bed dryers (FBDs) are used in the pharmaceutical industry to remove excess moisture from granule prior to tablet formation. As granule moisture content is reduced from its initial to final state, the velocity required to fully fluidize the granule decreases and the bed voidage decreases. The change in these fluidization properties are attributed to the decrease in the interparticle force load created by a reduction in liquid bridging as moisture is removed. During constant velocity drying, these fluidization properties result in a bubbling fluidization state, which evolves into a bubble coalescing regime as drying proceeds. This behaviour was identifiable using pressure fluctuation time-series analysis techniques.<p> Distributor design studies using dry and wet granule in a conical fluidized bed suggest that the punched plate design limits bubble coalescence when compared to the perforated plate and Dutch weave mesh designs. Furthermore, the Dutch weave results in extensive segregation, which is undesirable from a fluidization perspective. Local drying hydrodynamic measurements using x-ray densitometry found that the punched and perforated plates generate a centralized bubbling core region during drying with a defluidized bed periphery. This fluidized core region grows as drying proceeds until the defluidized region disappears. Under the same operating conditions, a porous plate distributor creates extensive channelling and defluidization across the entire bed cross-section during the constant rate period of drying. These poor fluidization characteristics are a result of the porous plate introducing the gas into the bed as a fine dispersion.<p> Lastly, the hydrodynamics associated with the conical vessel geometry improves the circulation and mixing patterns in fluidized bed dryers. This is especially the case in the entry region of the conical bed where the high inlet gas velocity prevents defluidization around the periphery of the bed. The straight walled geometry of the cylindrical bed resulted in defluidization in this area. As a result, the hydrodynamics associated with bubbling differ significantly between the geometries over the course of drying.

In this study, we explored the antecedents, consequences, and boundaries of team effectiveness and organizational performance. Specifically, we examined the relationship between team leadership and team effectiveness, and the relationships between team and organizational performance. We collected data from 15 ocean vessel teams and four executive & middle-level managers. The results showed that both team climate and team leaderships had a positive effect on team effectiveness. In addition, team effectiveness was positively related to organizational performance.

Design options have been evaluated for the Modular Helium Reactor (MHR) for higher temperature operation. An alternative configuration for the MHR coolant inlet flow path is developed to reduce the peak vessel temperature (PVT). The coolant inlet path is shifted from the annular path between reactor core barrel and vessel wall through the permanent side reflector (PSR). The number and dimensions of coolant holes are varied to optimize the pressure drop, the inlet velocity, and the percentage of graphite removed from the PSR to create this inlet path. With the removal of ~10% of the graphite from PSR the PVT is reduced from 541 0C to 421 0C. A new design for the graphite block core has been evaluated and optimized to reduce the inlet coolant temperature with the aim of further reduction of PVT. The dimensions and number of fuel rods and coolant holes, and the triangular pitch have been changed and optimized. Different packing fractions for the new core design have been used to conserve the number of fuel particles. Thermal properties for the fuel elements are calculated and incorporated into these analyses. The inlet temperature, mass flow and bypass flow are optimized to limit the peak fuel temperature (PFT) within an acceptable range. Using both of these modifications together, the PVT is reduced to ~350 0C while keeping the outlet temperature at 950 0C and maintaining the PFT within acceptable limits. The vessel and fuel temperatures during low pressure conduction cooldown and high pressure conduction cooldown transients are found to be well below the design limits. The reliability and availability studies for coupled nuclear hydrogen production processes based on the sulfur iodine thermochemical process and high temperature electrolysis process have been accomplished. The fault tree models for both these processes are developed. Using information obtained on system configuration, component failure probability, component repair time and system operating modes and conditions, the system reliability and availability are assessed. Required redundancies are made to improve system reliability and to optimize the plant design for economic performance. The failure rates and outage factors of both processes are found to be well below the maximum acceptable range.

[First published online] 2010-11-22 / 名古屋大学博士学位論文 学位の種類 : 博士(医学)(課程) 学位授与年月日:平成23年3月25日 澤井晶穂氏の博士論文として提出された

Thesis (Ph.D)--Biomedical Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Elliot Chaikof; Committee Member: Marc Levenston; Committee Member: Robert Nerem; Committee Member: Vincent Conticello; Committee Member: Yadong Wang. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Coronary arteries are the blood vessels supplying oxygen-rich blood to the heart muscles. Coronary artery calcium (CAC), which is the total amount of calcium deposited in these arteries, indicates the presence or the future risk of coronary artery diseases. Quantification of CAC is done by using computed tomography (CT) scan which uses attenuation of x-ray by different tissues in the body to generate three-dimensional images. Calcium can be easily spotted in the CT images because of its higher opacity to x-ray compared to that of the surrounding tissue. However, the arteries cannot be identified easily in the CT images. Therefore, a second scan is done after injecting a patient with an x-ray opaque dye known as contrast material which makes different chambers of the heart and the coronary arteries visible in the CT scan. This procedure is known as computed tomography angiography (CTA) and is performed to assess the morphology of the arteries in order to rule out any blockage in the arteries. The CT scan done without the use of contrast material (non-contrast-enhanced CT) can be eliminated if the calcium can be quantified accurately from the CTA images. However, identification of calcium in CTA images is difficult because of the proximity of the calcium and the contrast material and their overlapping intensity range. In this dissertation first we compare the calcium quantification by using a state-of-the-art non-contrast-enhanced CT scan method to conventional methods suggesting optimal quantification parameters. Then we develop methods to accurately quantify calcium from the CTA images. The methods include novel algorithms for extracting centerline of an artery, calculating the threshold of calcium adaptively based on the intensity of contrast along the artery, calculating the amount of calcium in mixed intensity range, and segmenting the artery and the outer wall. The accuracy of the calcium quantification from CTA by using our methods is higher than the non-contrast-enhanced CT thus potentially eliminating the need of the non-contrast-enhanced CT scan. The implications are that the total time required for the CT scan procedure, and the patient's exposure to x-ray radiation are reduced.

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Slėginiams indams ir įrangai keliami griežti stiprumo ir patikimumo reikalavimai, kurie reglamentuojami tarptautinių ir vietinių standartų. Keičiant slėginio indo eksploatavimo sąlygas ir parametrus, būtina atlikti jo stiprumo įvertinimą. Tiriama talpykla, kurioje numatyta laikyti emulsinį kurą, esant atitinkamo dydžio vidiniam slėgiui. Tyrimas atliekamas naudojant baigtinių elementų metodo programinį paketą SolidWorks Simulation, kuris leidžia modeliuoti talpyklą kevaliniais elementais ir įvertinti skirtingų apkrovimo būdų įtaką bendram konstrukcijos įtempių būviui. Tyrimas parodė, kad pavojingiausiose vietose įtempiai neviršija reglamentuojamų leidžiamų įtempių reikšmių ir talpykla yra tinkama, esant naujoms eksploatavimo sąlygoms. / The requirements of strength and reliability for pressure vessel and equipment are defined by international and local standarts and codes. In case of change of working condition and parameters, it is necessary to define the strength of the structure. The vessel under consideration is projected to contain emulsified fuel under internal pressure. The finite element software package SolidWorks Simulation is used for research. It allows to model the pressure vessel by shell elements. The combined classes of stress due to a combination of loads are deffined. The research shows that the stress intensity in the ares of maximum identified stresses does not exceed the allowable stress and the pressure vessel is proper for operation.