Characterization of Gas-to-Liquid (GTL) and Alaska North Slope Crude (ANSC) Oil Blend Properties for Flow Through the Trans Alaska Pipeline System (TAPS) by Density and Viscosity Measurements

As part of a major project on studying the transportation of gas-to-liquids (GTL) through the existing Trans Alaska Pipeline System (TAPS), the density and viscosity of GTL and the Alaskan North Slope Crude (ANSC) and their blends were measured. All density and viscosity measurements were performed, using the Anton-Paar vibrating tube densitometer and a cone and plate viscometer respectively, at temperatures ranging from 20 ^oC to 60 °C at atmospheric pressure. The accuracy of the measured data has been ascertained. In addition to the density and viscosity data, other data reported for GTL and ANSC include compositions. Finally, generalized dens ty and viscosity correlations for the measured data are presented.     

Screening of Oil Pools on Alaskan North Slope and Phase Behavior Study of Viscous Oil and CO2 System in Conjunction with CO2 Sequestration

Carbon dioxide gas, a greenhouse gas (GHG), is released in the atmosphere by combustion of solid waste, wood, and fossil fuels for energy generation. Due to conspicuous absence of CO₂ sequestration studies for Alaska, the study of CO₂ sequestration options on North Slope has a very important role to play. The screening of the oil reservoirs to evaluate the technical feasibility with respect to their CO₂-EOR potential was performed by calculating the rank of the oil reservoirs with parametric approach. CMG-WinProp® simulator was used to predict phase behavior for CO₂ injection in viscous oil by tuning the equation-of-state.     

FPGA-Accelerated Deformable Image Registration for Improved Target-Delineation During CT-Guided Interventions

Minimally invasive image-guided interventions (IGIs) are time and cost efficient, minimize unintended damage to healthy tissue, and lead to faster patient recovery. With the advent of multislice computed tomography (CT), many IGIs are now being performed under volumetric CT guidance. Registering pre-and intraprocedural images for improved intraprocedural target delineation is a fundamental need in the IGI workflow. Earlier approaches to meet this need primarily employed rigid body approximation, which may not be valid because of nonrigid tissue misalignment between these images. Intensity-based automatic deformable registration is a promising option to correct for this misalignment; however, the long execution times of these algorithms have prevented their use in clinical workflow. This article presents a field-programmable gate array-based architecture for accelerated implementation of mutual information (Ml)-based deformable registration. The reported implementation reduces the execution time of MI-based deformable registration from hours to a few minutes. This work also demonstrates successful registration of abdominal intraprocedural noncontrast CT (iCT) images with preprocedural contrast-enhanced CT (preCT) and positron emission tomography (PET) images using the reported solution. The registration accuracy for this application was evaluated using 5 iCT-preCT and 5 iCT-PET image pairs. The registration accuracy of the hardware implementation is comparable with that achieved using a software implementation and is on the order of a few millimeters. This registration accuracy, coupled with the execution speed and compact implementation of the reported solution, makes it suitable for integration in the IGI-workflow.     

Distribution of SIV infection in the gastrointestinal tract of rhesus macaques at early and terminal stages of AIDS

Intestinal tissues from SIV-infected rhesus macaques with subclinical as well as with terminal SIV disease were evaluated for SIV infection. SIV-infected mononuclear cells were detected throughout the gastrointestinal tract in all animals. In early infection, SIV-infected cells were diffusely distributed in lymphoid tissue and lamina propria, whereas in late stages of the disease, the viral infection was more severe and widely disseminated. Lymphoid cells of the lamina propria and gut-associated lymphoid tissue were the primary targets of SIV.     

Numerical analysis of elastic contact problems using the boundary integral equation method. Part 1: Theory

A boundary integral equation formulation for the analysis of two-dimensional elastic contact problems with friction is developed. In this formulation, the contact equations are written explicitly with both tractions and displacements retained as unknowns. These equations are arranged such that a blocked coefficient matrix results. An incremental and iterative procedure is discussed which, in the case of proportional loading, modifies only the equations in the potential contact zone.     

Numerical analysis of elastic contact problems using the boundary integral equation method. Part 2: Results

This paper gives solutions to various frictionless and frictional contact problems using the boundary integral formulation developed in Part 1. A range of problems is considered in order to demonstrate the applicability of the approach. In most cases equal size linear elements are found to give best results. In the case of frictional problems the arrangement of strick-slip zones is affected by the node locations and a relatively large number of elements may be required to produce satisfactory results. In all cases, the boundary integral equation method yields numerical solutions that are in very good agreement with the analytical solutions to which they are compared.     

REACTION FRONT PROPAGATION CHARACTERISTICS IN NON-CATALYTIC EXOTHERMIC GAS-SOLID SYSTEMS

Synthesis of transition metal nitrides and hydrides can be accomplished in the self propagating high temperature regime. A one dimensional model is proposed to study the effects of various operating parameters on the stability of the combustion front, to which gaseous oxidizer is fed by a process of filtration through the permeable solid. Different propagation phenomena can exist depending on the pressure of the gaseous reactant. The stability criteria derived for solid-solid systems can be extended for gas-solid systems at high pressures. At very low pressures filtration combustion is always stable. Systems which show unstable front propagation under adiabatic conditions have been observed to become more unstable due to heat losses.