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Title: IMPACT OF DATA SHAPE, FIDELITY, AND INTER-OBSERVER REPRODUCIBILITY ON CARDIAC MAGNETIC RESONANCE IMAGE PIPELINES
Creator: Obioma, Blessing Ngozi
Date: 2020
Description: Artificial Intelligence (AI) holds a great promise in the healthcare. It provides a variety of advantages with its application in clinical...
Show moreArtificial Intelligence (AI) holds a great promise in the healthcare. It provides a variety of advantages with its application in clinical diagnosis, disease prediction, and treatment, with such interests intensifying in the medical image field. AI can automate various cumbersome data processing techniques in medical imaging such as segmentation of left ventricular chambers and image-based classification of diseases. However, full clinical implementation and adaptation of emerging AI-based tools face challenges due to the inherently opaque nature of such AI algorithms based on Deep Neural Networks (DNN), for which computer-trained bias is not only difficult to detect by physician users but is also difficult to safely design in software development. In this work, we examine AI application in Cardiac Magnetic Resonance (CMR) using an automated image classification task, and thereby propose an AI quality control framework design that differentially evaluates the black-box DNN via carefully prepared input data with shape and fidelity variations to probe system responses to these variations. Two variants of the Visual Geometric Graphics with 19 neural layers (VGG19) was used for classification, with a total of 60,000 CMR images. Findings from this work provides insights on the importance of quality training data preparation and demonstrates the importance of data shape variability. It also provides gateway for computation performance optimization in training and validation time.
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Title: A Network Analysis to Examine the Construct of Acculturative Stress in Mexican Americans
Creator: Mosqueda, Andrea I
Date: 2020
Description: Acculturative stress (AS) is a negative consequence of acculturation and occurs when acculturation is problematic for the individual. There is...
Show moreAcculturative stress (AS) is a negative consequence of acculturation and occurs when acculturation is problematic for the individual. There is a substantial variation in AS phenomena across different cultural/ethnic groups, across individual variables (e.g., sex, age, education, attitude, cognitive style), and across social variables (e.g., contact, social support, status). There does not seem to be one specific way in which AS affects all groups or individuals. Elevated levels of AS are associated with multiple manifest difficulties, including family dysfunction, geographical separation from family, low-income levels, and non-positive expectations for the future. AS has been associated with outcomes such as anxiety, depression, suicidal ideation, and feelings of isolation and alienation. Using a network analysis approach, this exploratory study examined the structure of the construct of AS as represented in the Social, Attitudinal, Familial, and Environmental (SAFE) AS Scale, a measure used to assess the AS construct across four contexts. Results of the network analysis of AS aspects suggest that the AS construct is best understood as a latent variable rather than as a network of interacting AS aspects, and that distress is related to particular aspects of AS. The present study findings suggest a particular model of relations between latent AS, its manifest aspects, and clinical outcomes. Further research can help to better understand the relationship between individual AS aspects (i.e., treatment targets) and treatment goals of impacting AS-related outcomes (e.g., distress), as well as the mechanisms of change.
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Title: EFFECTIVENESS OF CLEANING STRATEGIES FOR REMOVING MILK CHOCOLATE FROM PILOT-SCALE PIPE/VALVE ASSEMBLY AND CHOCOLATE PROCESSING EQUIPMENT
Creator: Zhang, Liyun
Date: 2019
Description: Dark chocolate manufactured on shared processing lines with milk chocolate is a high-risk food for consumers with milk allergy. Inadequate...
Show moreDark chocolate manufactured on shared processing lines with milk chocolate is a high-risk food for consumers with milk allergy. Inadequate cleaning of shared chocolate manufacturing equipment can result in milk contamination of subsequent products, and product recalls. Limited information is available on the effectiveness of different cleaning procedures for preventing the transfer of milk to dark chocolate processed on shared equipment. Pilot-scale experiments investigated the effectiveness of three dry cleaning methods: 1) no cleaning, 2) pig purging, and 3) a cocoa butter flush (40°C, 1 hour) for removing milk chocolate residue from a heated (40ºC) standard (1.5” OD) sanitary stainless steel pipe (30.5 cm length) and attached butterfly or ball valve. After cleaning, milk-free dark chocolate (~27 kg, 40°C) was pumped through the pipe/valve combination. Dark chocolate push-through samples were collected and analyzed for milk concentrations with a Neogen Veratox total milk ELISA kit. Experiments with no cleaning resulted in initial milk concentrations up to 6,070 (9.6% CV) ppm milk and up to 14,900 (0.3% CV) ppm milk for the pipe/butterfly valve and the pipe/ball valve, respectively. Cocoa butter recirculation through the pipe/butterfly valve decreased initial milk concentrations to 680 (10.3% CV) – 2720 (2.6% CV) ppm milk. Use of a pig purging dramatically reduced milk levels to 45 (4.3% CV) – 180 (15.7% CV) for the pipe/butterfly valve and below limit of quantification of ELISA (LOQ, 2.5 ppm milk) for the pipe/ball valve. After most cleaning treatments, > 14 kg of dark chocolate push-through was required to obtain milk levels < LOQ.A second set of pilot-scale experiments determined the efficacy of cleaning procedures for removing milk chocolate from selected chocolate processing equipment. Three cleaning methods explored removal of milk chocolate from a ball mill and conche: 1) no cleaning, 2) a cocoa butter flush (40°C, 5 min), and 3) wet cleaning (detergent-rinse-air dry). After cleaning, three batches of milk-free dark chocolate (40°C) were processed in the ball mill (~0.35 kg) and conche (2.5 kg), and each batch was collected and analyzed for milk. Milk chocolate (1.5 kg) was processed on a 3-roll refiner, followed by push-through with dark chocolate (~8 kg), with 0.3 kg samples collected at 5-min intervals. Milk was not detected (Show less

Title: Synthesis and Processing of NaSICON Membranes with High Ionic Conductivity and Good Mechanical Strength
Creator: Chiang, Shan-Ju
Date: 2019
Description: Natrium super ion conductors (NaSICONs), Na1+xZr2SixP3-xO12 (0 ≤ x ≤ 3) are compounds that commonly used as solid electrolytes and membranes...
Show moreNatrium super ion conductors (NaSICONs), Na1+xZr2SixP3-xO12 (0 ≤ x ≤ 3) are compounds that commonly used as solid electrolytes and membranes of sodium based batteries, or in gas sensors and fuel cells due to their high sodium ion conductivity, low thermal expansion, and ability to accommodate ions in the lattice. However, NaSICON with high relative density (> 97%) and minimum impurity phases is found to be very difficult to obtain. Furthermore, the cost of the general synthesis methods is a serious drawback. Multi-high-temperature heating procedures is often employed to increase the density and to attain the single phase NaSICON because the particle size and free ZrO2 are better reduced. This research explores the possibility of densification and synthesis of NaSICON in one high-temperature reaction through a novel process termed Integrated Mechanical and Thermal Activation (IMTA) and the co-sintering behavior as well as the NaSICON composite membranes from tape casting. The sintering temperature of NaSICON was decreased by mechanical activation at room temperature using high-energy ball milling. Sintered NaSICON-based materials showed highest total ionic conductivity of 1.45 × 10-3 S cm-1 at room temperature and high density of 3.155 g cm-3 (96.5%). An alternative to obtaining full densification (99%) of NaSICON ceramics was developed utilizing traditional solid-state reaction. This sintered NaSICON without any sintering aid exhibited the total conductivity, 6.59 × 10-4 S cm-1 at 25 °C, and the highest density of 3.238 g cm-3, a better than 2.6% enhancement from the original samples.The second part of the work has comprised of successful fabrication of NaSICON/polymer composite membranes and bi-layered NaSICON/stainless steel membranes to enhance the mechanical flexibility of pure NaSICON films. The effect of different particle sizes of stainless steel on the sintering behavior and shrinkage rate were studied systematically. The effect of solid content in the slurry was also studied to control the density of both support layer and NaSICON body. The affect structural ratios have on co-sintered tapes along with ionic conductivity was investigated using Electrochemical Impedance Spectroscopy (EIS). The co-sintered membrane exhibited a total conductivity as high as 4.580 × 10-4 S/cm at room temperature. EIS results showed the high Na-ions conductivity strongly depends on the feature of grain boundary and the high densification of NaSICON layer.
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Title: An aircraft hangar and the study of long-span metal structures
Creator: Sharpe, David C. (David Carold)
Date: 1962-06
Description: The study of long-span structures developed from a design problem for an aircraft hangar. The problem of the aircraft hangar was concerned...
Show moreThe study of long-span structures developed from a design problem for an aircraft hangar. The problem of the aircraft hangar was concerned with the development of a reasonable structurtal type into an architectural solution. Several types were considered; the truss, the arch, a rigid frame system in prestressed concrete. These were discarded in favor of a rigid frame system of steel that seemed to give the best visual solution.
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