bluuebunny/crossref_metadata_2025 huggingface dataset:
Advancing and sustaining a clinical teacher preparation partnership
Authors:   , Garrido Melissa Downey , Bureau W. Edward
Published: July 2021

The national call to "turn [teacher education] upside down" (National Council for Accreditation of Teacher Education, Report of the Blue Ribbon Panel on Clinical Preparation and Partnerships for Improved Student Learning [NCATE], 2010, p. ii) and states' subsequent commitments to pilot recommendations necessitates study of successful clinical teacher preparation partnerships (CTPP). The purpose of this study was to discover what is/was required to advance and sustain one successful urban southern California CTPP. A qualitative case study was applied, and semi-structured interviews were conducted with nine school-university CTPP developers and sustainers. Two interview protocols, unique to the role of the interviewee, were developed utilizing Bolman and Deal's (2003) Four Frames: a) structural, b) human resources, c) political, and d) symbolic. Pertinent to each frame, interviewees were asked to address a) strategies or protocols, b) approaches for managing and supporting these strategies and challenges encountered, and c) recommendations for others embarking on a CTPP. A qualitative software program was utilized to code interview transcripts. Field notes from interviews/CTPP site visits and artifacts, including CTPP promotional materials, published CTPP studies, written student teacher testimonials, and photographs of relevant CTPP documentation were collected and underwent aggregate case study analysis. Four themes emerged from the findings a) collaboration, b) belief, c) autonomy, and d) relationships. Results included Symbolic-Purposeful partnerships prioritizing urban children seemed to provide an ideal canvas for advancing and sustaining CTPP; Structural-Professional autonomy seemed necessary to navigate institutional bureaucracy and organically develop CTPP's infrastructure; Political-The prime mover's unyielding belief and placid persistence to create a successful Pilot CTPP seemed to spur a critical mass of player buy-in. Recruitment efforts seemed most successful when delivered by CTPP student teachers; and Human Resource-A university presence and tenacious attention to the multiple inter-institutional and intra-university relationships seemed key to sustaining the partnership. A people-focused field supervisor, paired student teachers and large cohorts in centralized school sites, appeared to optimally support relationships. Collaboration was suggested in all four vantage points as key to sustaining and advancing the CTPP. While there is currently no blueprint for clinical teacher preparation partnerships, this case study can provide an advisory template for scale-up efforts to transform teacher education programs in California and on a national scale.
Quantum dot intermediate band solar cells
Authors:   , Jenks Steven Evans , Gilmore Robert
Published: July 2021

The main limitation of the conventional solar conversion device is that low energy photons cannot excite charge carriers to the conduction band, therefore do not contribute to the devices's current, and high energy photons are not efficiently used due to a poor match of the solar spectrum to the energy gap. However, if intermediate levels are introduced into the energy gap of a conventional device, then low energy photons can be used to promote charge carriers in a stepwise manner to the conduction band thereby enhancing the current while maintaining a large open-circuit voltage. This concept is called the intermediate band solar cell and increases the efficiency beyond the thermodynamic limits of the conventional device. A device based on the confined electron levels of quantum dots called the quantum dot intermediate band solar cell is a physical realization of the intermediate band solar cell. In this work, we propose design criteria and optimal material systems that are considered candidates for the quantum dot intermediate band solar cell. To search for optimal materials, the finite element method is developed and MATLAB code is designed in the context of quantum and continuum mechanics with the sophistication necessary to allow for three dimensional numerical simulations that incorporate realistic assumptions about the quantum dot. The materials considered in this work are the technologically important III-V compound semiconductors and their alloys. Numerical simulations are carried out on quantum dot geometries that have been experimentally observed during self-assembled growth, the technology proposed to achieve the quantum dot intermediate band solar cell, and those material systems that have properties that match those of the intermediate band solar cell with efficiency greater than 46% for unconcentrated light and greater than 62% for fully concentrated light are identified as optimal materials for the quantum dot intermediate band solar cell.
An examination of an acceptance-based behavioral intervention for obesity prevention in at risk college females
Authors:   , Katterman Shawn Nicole , Lowe Michael R.
Published: July 2021

Given the limits of obesity treatment, cost-effective obesity prevention programs are clearly indicated. Epidemiological data suggest that young adult women are prone to weight gain, particularly those who are already overweight. The current study examined the efficacy of an acceptance-based behavioral approach for obesity prevention in female college students with above average, but non-obese BMIs (BMI of 23-30 kg/m2). Fifty-eight participants were randomized to an experimental group who attended eight small-group sessions over 16 weeks (n = 29), or an assessment-only control group (n = 29). Group sessions included behavioral (e.g., monitor weight and calories, increase exercise) and acceptance-based (e.g., distress tolerance, willingness to experience cravings) strategies for long-term weight control. Participants were assessed at baseline, 6 weeks, and 16 weeks. At baseline, psychological flexibility (i.e., the ability to choose from a full repertoire of behavior including that which engenders uncomfortable internal experiences), was inversely related to BMI, weight self-efficacy, and emotional eating (p-values all < .01). The intervention significantly reduced weight in the experimental group by 1.92 kg (SD = 3.57) and the control group gained 0.09 kg (SD = 2.34) at 16 weeks, F(1,40) = 5.282, p = .027, [eta]2 = 0.117. The intervention also increased weight self-efficacy, physical activity, and psychological flexibility related to physical activity at 6 weeks compared to controls, but group differences did not persist to 16 weeks. The current study was the first to examine weight gain prevention in this at risk population and results indicate that a brief behavioral intervention utilizing acceptance-based strategies produces weight reduction over 16 weeks. Additionally, the study was the first to examine acceptance-based variables in this group and indicates that several weight related outcomes are cross-sectionally related to psychological flexibility. The lack of significant group differences in behavioral and psychological variables at 16 weeks suggests that intervention participants may have used different strategies to achieve the weight reduction and/or the intervention may need to meet more frequently to show continued effects on behavioral and psychological variables. Regardless, results from this novel study indicate that the current intervention has promise as a cost-effective obesity prevention intervention. Future research should examine mechanisms of change and longer term follow up.
Essays in mergers and acquisitions
Authors:   , Ouyang Wenjing , Szewczyk Samuel Hideyo
Published: July 2021

Mergers and acquisitions are one of the most important corporate investment decisions that are often strategic. During the decision making, managers and shareholders are exposed to all sorts of information sets regarding merger opportunities and deal evaluation. In this dissertation, I examine whether managers and shareholders use valuable information from financial advisors and the financial market and disregard potentially misleading information from financial advisors when making merger investment decisions. The first essay is titled "Do Shareholders Listen? M&A Advisor Opinions and Shareholder Voting. Recent studies find that merger advisors, in particular those of the acquirer, often face conflicts of interest and present overly optimistic opinions about a deal. It is not clear, however, how shareholders react to these opinions. Using a sample of mergers announced from 2000 to 2006, we examine whether target and acquirer advisors' opinions (valuation of target equity, long-term earnings forecasts, and affiliated analyst recommendations) impact how acquirer shareholders vote on mergers. Our results indicate that target advisor opinions, but not those of acquirer advisors, significantly impact shareholder voting. Further, if a deal receives higher shareholder support, the merger advisor is more likely to be retained in future deals. Finally, acquirer advisor opinions are negatively related to post-merger performance. We conclude that shareholders are able to discern the potential conflict of interest of merger advisors and follow the advice of the less-optimistic target advisors. Our study provides important evidence for the ongoing debate about regulatory reform governing investment banking transactions. The second essay is titled "Stock Price Idiosyncratic Information and Merger Investment Decisions". I define stock price idiosyncratic information (SPII) as investors' firm-specific information impounded into stock price through informed trading. My study examines whether SPII provides managers the new information about the value of growth opportunities and improves merger investment decisions. Focusing on 2,018 major merger transactions announced during the period from 1990 to 2006, I find the acquirer SPII increases the sensitivity of merger investment to q. It is positively associated with acquirer announcement return, combined merger return, long-run abnormal return, and post-merger operating performance. Furthermore, these relations are mainly driven by acquirers with high q or blockholder ownership. My main results are robust to the endogeneity issue and the inclusion of manager's private information. Overall, these results support my learning hypothesis. Further, management learning efficiency is positively related with firm growth opportunities, management quality, and corporate governance. My study provides important evidence that managers learn from the stock market in making merger investment decisions.
Structural identification of a complex structure using both conventional and multiple model approaches
Authors:   , Weidner Jeffrey Scott , Moon Franklin L.
Published: July 2021

The confluence of a debilitated, often obsolete bridge population nearing the end of its design life with a massive shortfall of funding for rehabilitation and replacement has led to an unsustainable balancing act for bridge owners. One tool for addressing this issue is Structural Identification (St-Id), a six-step process for effectively integrating subjective information from visual inspections, with analytical modeling and experimental investigations to provide a more robust and defendable foundation for decision-making regarding constructed systems. In an effort to understand and document St-Id from a global perspective, the International Bridge Study (IBS) brought researchers from all over the world to demonstrate various techniques and technologies on a single test specimen in New Jersey. Through this application a comprehensive documentation of a best-practices application of St-Id was developed and numerous advances to each step of the process and their integration were achieved. These advances included formalization of the criteria for bridge selection as a candidate for St-Id, development of a framework for instrumentation design considering safety and test objectives, design and implementation of a distributed data acquisition system with a real-time visualization interface and spatially-correlated data interpretation. As part of this application some shortcomings associated with conventional model-experiment correlation approaches were identified. The second phase of the research aimed to develop and validate rigorous methods to mitigate these shortcomings. This research examined multiple-model approaches such Markov Chain Monte Carlo (MCMC) and multi-dimensional MCMC methods through both a benchmark numerical problem and the IBS Bridge. The primary findings in this phase included the difficulty in framing the problem to fully map the model space using Reversible Jump MCMC, an alternative approach through a multi-dimensional MCMC method, the difficulty in applying MCMC to actual bridges due to the complexity of the likelihood space and that MCMC can implicitly account for interaction between parameters through covariance and correlation coefficients. In general, the response predictions from the MCMC chains were more robust and informative than the results from the single model correlation.
Correlating the structure and properties of highly plastic segmented polyurethane nanocomposites containing low silicon dioxide filler weight fractions
Authors:   , Hood Matthew Allen , Li Christopher Y.
Published: July 2021

Segmented polyurethanes (SPUs), as a class of elastomers, display a large degree of toughness and elasticity. To modify the mechanical properties of an SPU matrix, high elastic modulus fillers may be added. In this work we systematically correlated the relationship between silicon dioxide (silica) particles size and functionality on the resulting mechanical properties of the SPU-silica composites. SPU was synthesized of poly(tetramethylene glycol) soft segments, which contribute to the extensibility of the SPU, and hexamethylene diisocyanate-butanediol hard segments (HS), which contribute to the SPUs modulus and toughness. Blends of SPU with 25 wt% HS and silica nanoparticles, micrometer-sized silica particles and methyl modified silica nanoparticles were prepared. SPU-silica particle composites were also evaluated when silica particles were covalently attached to the SPU matrix. The HS concentration of in situ SPU-silica particle composites was also increased to 35 wt% and 45 wt%. Blended composites displayed poor mechanical properties due to a weak interaction of silica particles with the SPU matrix and poor control over silica particle location within the composite. Covalently attached silica particles were relegated to HS-rich domains, introduced an astonishing 10-fold increase in strain-at-break (from 200 % for the pristine SPU to >2100 % with addition of 0.5 wt% and 1.0 wt% silica nanoparticles concentrations). A decrease in elastic modulus was observed due to disruption of the HS crystallinity. In situ SPU-amine modified silica nanoparticle composites displayed the greatest increase in strain-at-break over the largest range of silica nanoparticle concentrations. The variation in properties for SPU-amine modified silica nanoparticles composites was due to a difference in reactivity and nature of the amine functional silica nanoparticles compared to that of the unmodified silica nanoparticles. Micrometer-sized silica particles and di- and octa-functional polyhedral oligomeric silsesquioxane (POSS) molecules were added to an SPU matrix in situ. Mechanical reinforcement was not observed for di-functional POSS, which did not act as a cross-linking agent. We have established a correlation between silica particle placement within an SPU matrix and the structure-properties relationship of the final polymer composites. A molecular level representation of the SPU chains near the silica fillers was proposed for the SPU-silica filler composites. A cause for the extraordinary increase in strain-at-break with in situ addition of the silica fillers at low weight concentrations is proposed.
The Experience of Migration and Acculturation for International Students As Expressed in the Handmade Book
Authors:   , Camilleri Marya Frieda , Gerber Nancy E.
Published: July 2021

The purpose of this research study was to explore the lived experience of migration and acculturation for international students as expressed through the handmade book and open-ended responsive interview. A review of the literature included a historical background of immigration in the United States, an explanation of culture and cultural adjustment processes, a review of acculturation concerns that have been experienced by international students in the United States, a review of this population's utilization of services and preferences for culturally relevant approaches, and an explanation of art therapy-and the handmade book in particular-as a culturally relevant technique for addressing migration, acculturation, and other life transitions. The literature review revealed that there is a need for more systematic research on the use of art therapy methods-particularly the handmade book-with international students. This study used a phenomenological method to collect and analyze data, and enrolled four international students. All participants described their ethnicity or ancestry as Asian. The sample consisted of one female participant from Korea, and two female participants and one male participant from India. Participants ranged in age from 22 to 26, and they had lived in the U.S. for a range of approximately 1 to 6 years. Each participant created a handmade book about his or her migration and acculturation experiences and then participated in an open-ended responsive interview. The data analysis resulted in the identification of five composite essential structures. The artwork and verbal responses of all four participants reflected experiences of (a) remaining strongly rooted in family, values, and culture of origin, while branching out and adapting to a new culture; (b) sacrificing comfort and protection to explore, discover, achieve, and gain independence; (c) coping with transition and distance from family through social supports and new experiences; (d) integrating diverse personality traits and experiences into one piece of artwork; and (e) finding a voice through metaphors. Based on the composite essential structures, recommendations for applications of the handmade book include culturally relevant support services for international students on college campuses. The handmade book is also recommended for immigrants, refugees, and other individuals, groups, couples, or families experiencing life transitions. Future studies on the handmade book are recommended, with larger, more diverse samples of participants.
Exploration of the effects of electrospray deposition spraying parameters and incident laser wavelength on matrix assisted laser desorption ionization time-of-flight mass spectrometry
Authors:   , Haulenbeek Jonathan R. , Owens Kevin Glenn
Published: July 2021

This thesis investigates the use of electrospray deposition (ESD) as a sample preparation technique for matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) and laser wavelength effects on the MALDI-TOFMS signal. A brief description of critical ESD parameters is provided and studies aimed at understanding the parameters that define the spraying diameter are presented. The experimental data suggest that the solvent and solute identity, solute concentration, spraying flow rate and spraying distance all affect the final sprayed sample diameter and the morphology of the amorphous particles deposited on the sample surface. The invention of a controlled ESD technique is described and both the gross sample morphology and sprayed particle morphology are discussed. Key spraying parameters of the controlled ESD technique are investigated using a combination of scanning electron microscopy, laser confocal microscopy and MALDI-TOFMS. Samples sprayed for longer time periods and sprayed from a larger spraying distance yielded MALDI samples with increased analyte sensitivity. A MALDI-TOFMS instrument equipped with two lasers operating at 355 and 337nm was used to investigate analyte response at the two wavelengths. Solid state and solution phase UV-visible absorption spectroscopy and a quartz-crystal micro-balance were also used to investigate the differences in absorption and desorption of MALDI matrix compounds at both wavelengths. Common MALDI matrix compounds were shown to have similar absorbance at both wavelengths in the solid state, however, the mass of desorbed material per laser shot was shown to be greater when using a 355nm laser. The absolute analyte signal at the optimal matrix-to-analyte molar ratio is greater when using an incidence wavelength of 355nm. The effect of dissolution solvent on MALDI signal was investigated using the ESD technique. The addition of acetonitrile into solutions of methanol was shown to decrease the observed analyte signal. A mixture of chloroform and methanol produced analyte signals greater than those generated by a solution of methanol alone. The data suggest that acetonitrile quenches the MALDI signal when using ESD as a sample preparation technique. The addition of chloroform as a co-solvent may affect the particle morphology of the sprayed samples leading to the increased analyte signal.
Wastewater tracer study utilizing carbamazepine, triclocarban and triclosan in the Philadelphia waterway
Authors:   , Alshouli Michele M. , Foley Joe Preston
Published: July 2021

Pharmaceuticals and personal care products (PPCPs) are chemicals that are manufactured and used extensively throughout the world. PPCPs end up in the wastewater system due to disposal or human waste. When treated wastewater is released back to the river, trace amounts of these chemicals are found in source water, which contaminate drinking water and pose a concern of unknown potential harm to the aquatic environment. Recent studies show PPCPs are an environmental hazard to aquatic organisms and humans as well. Since their detection in clean water in the late 1990s, many methods are being developed for analysis of PPCPs in the aquatic environment.1 The present study establishes a useful analytical method for PPCPs and uses selected PPCPs as tracers to investigate the impact of wastewater discharge on the waterways and to estimate the occurrence of PPCPs. This thesis entails three main objectives; first, to develop a sensitive and robust method for three chemical tracers; second, to quantitate these tracers in the Philadelphia watershed; and third, to develop a monitoring program in the Philadelphia watershed to survey the impact that wastewater has on source water. A method was developed for the simultaneous analysis of Carbamazepine (CBZ), Triclocaban (TCS), and Triclosan (TCS) by solid-phase extraction (SPE) followed by high performance liquid chromatography (HPLC) with diode array detection (DAD). The calibration range was from 1-100 ug/L. All compounds had a coefficient of determination (r2) > 0.9951, based on a minimum of 7 data points used in the regression of the calibration curve. Procedural recoveries with this method were 90%, 85%, and 80% for Carbamazepine, Triclocarban and Triclosan, respectively. Precision of the method was assessed by comparing repeatability and intermediate precision results with pre-determined criteria. For repeatability for intra-day precision, an RSD less than %16 was achieved. For intermediate precision, an RSD less than 9% was obtained. Procedural RSD was also determined to be less than 12%. The fate of the chemical tracers was quantitated after the treatment process to assess their use as tracers. All three tracers were detected before and after wastewater treatment. Detections in wastewater effluent were in the ranges of 0.4 - 5.0 ug/L for Carbamazepine, 0.05-0.09 for Triclocarban, and 0.29-0.47 ug/L for Triclosan. It was shown that Carbamazepine, Triclocarban, and Triclosan are removed through the wastewater treatment by 43% to 93%, 86 to 89%, and 71 to 83%, respectively. Concentrations found in source water are in the ranges of 0.006-1.1 ug/L for Carbamazepine, 0.004 - 0.48 ug/L for Triclocarban, and 0.02-0.058 ug/L for Triclosan.
Electrospun cartilage glycosaminoglycans for biomimetic scaffolds
Authors:   , Dowd Sean Michael , Schauer Caroline L.
Published: July 2021

Osteoarthritis is a condition through which cartilage is broken down by the human body (1). Osteoarthritis of the knee affects approximately 84.5 million people over the age of 45 in the US alone, or over 27% of the entire population (1). In order to help combat such a debilitating condition, this study investigated electrospinning natural polymers that are found in human cartilage: hyaluronic acid and chondroitin sulfate. Polymer fibers were created using two different solvent systems: aqueous N,N - dimethylformamide and acetic acid. Optimization tests were performed on each sample to attempt to control factors such as fiber diameter and polymer concentration. In order to understand which system would be better for the human body, crosslinking and solubility studies were performed. When attempting to spin, it was discovered that only the solution containing aqueous N,N - dimethylformamide and an excess of HA could be successfully be electrospun and crosslinked.
Biotemplated nanostructured surfaces for enhanced two-phase heat transfer
Authors:   , King Stephen M. , McCarthy Matthew
Published: July 2021

The Leidenfrost phenomenon is the stable film boiling of a liquid droplet in proximity to a surface whose temperature is much higher than the boiling point of the liquid; caused by rapid vaporization of the droplet before it can come in contact with the surface. This scenario makes conduction through insulating vapor the only means of evaporating the droplet. It is desirable to offset or delay the onset of this occasion of poor heat transfer, the Leidenfrost point, in situations where droplet-to-surface contact is paramount; namely, nuclear reactor safety. Increasing surface hydrophilicity through the implementation of micro, nano, and hierarchical structures has been shown to increase phase-change heat transfer across a surface. In this work, attempts to delay the Leidenfrost phenomenon by tailoring surface wettability with various microstructures conformally coated with novel Tobacco mosaic virus-templated nickel nanostructures are made. Because of a solution based fabrication process, Tobacco mosaic virus nanostructures are potentially more integratable into real-world systems than traditionally fabricated nanostructures. Micropost arrays are patterned in such a way to determine whether the time limiting mechanism in Leidenfrost droplet evaporation is heat transfer or mass transfer dependent. In all, seven patterns (28 samples) with varying thermal conductivities, two-dimensional permeabilities, and heights are: fabricated from SU-8 (photolithography) and silicon (deep reactive-ion etching); tested to determine each surfaces' Leidenfrost point, i.e. the longest droplet evaporation time, through the use of a high-speed camera in concert with a stopwatch; and compared to the performance of flat and nanostructured only surfaces. SU-8 hierarchical posts outperform silicon hierarchical posts, increasing the Leidenfrost point by 175°C (20[mu]m tall) and 250°C (40[mu]m tall) over flat samples, with silicon hierarchies showing only modest improvement, < 100°C. Increase in two-dimensional permeability shows no extractable trend in Leidenfrost point; however, contact angle and post height appear to have less of an effect on the Leidenfrost point as two-dimensional permeability increases. Leidenfrost temperatures decrease with increasing effective thermal conductivity and there also appears to be a trend of increasing Leidenfrost point with increasing thermal resistance of post arrays. A model derived from the Navier-Stokes equations has been developed which predicts mass transfer as the limiting mechanism in Leidenfrost droplet evaporation. While this model does not accurately predict the values of evaporation times, it does predict the overall trend of decreasing evaporation time with increasing surface porosity.
Super-porous PVA hydrogels with controlled release of IGF-1 for cartilage tissue engineering
Authors:   , Martin Claire Elizabeth , Spiller Kara Lorraine , Zhou Guangdong , Liu Wei , Lowman Anthony M.
Published: July 2021

Repair or regeneration of articular cartilage remains one of the most difficult challenges in orthopedic medicine. Poly(vinyl alcohol) (PVA) hydrogels have shown promise as synthetic cartilage replacement materials, especially those that allow sustained release of insulin-like growth factor 1 (IGF-1). The goal of this study was to increase the porosity of the previously designed hydrogels that had an average pore size of 60 to 100[mu]m and a porosity of 60 to 70%, while maintaining IGF-1 release in order to increase infiltration of chondrocytes from surrounding cartilage. The hydrogels were prepared using a previously established, single step, double emulsion technique based on a water-oil-water (W1/O/W2) composition. IGF-1 was encapsulated in degradable poly(lactic-co-glycolic acid) (PLGA) microparticles (W1/O) embedded in non-degradable poly(vinyl alcohol) (PVA) hydrogels (W2). The effects of processing parameters such as volume and composition of the water and oil phases were evaluated towards increasing hydrogel porosity. Hydrogels of various formulations had interconnected pores from 40 to 600um and average pore size of up to 337 ± 205[mu]m, and porosities of 76% to 84%, all of which were increases over the previous design. The controlled release system sustained release of IGF-1 for 73 days in vitro, with an initial burst on the first day of 1.82 ± 1.15[mu]g/ml. In order to study the controlled release of IGF-1 on cartilage tissue engineering in vivo, the hydrogels were seeded with chondrocytes and implanted subcutaneously into the backs of nude mice and harvested after two and five weeks in vivo. The introduction of high levels of porosity to PVA hydrogels resulted in a reduction in mechanical properties but an increase in cartilage growth within the hydrogels. This study shows that the sustained release of IGF-1 can enhance tissue formation within the pores of a non-degradable hydrogel. The increase in porosity of the IGF1-eluting hydrogels may improve implant integration with surrounding tissue.
Pore-scale modeling of transport phenomena in vanadium redox flow batteries
Authors:   , Qiu Gang , Sun Ying
Published: July 2021

The vanadium redox flow battery (VRFB) has emerged as a viable grid-scale energy storage technology that offers cost-effective energy storage solutions for renewable energy applications. In this paper, a novel methodology is introduced for modeling of the transport mechanisms of electrolyte flow, species and charge in the VRFB at the pore scale of the electrodes; that is, at the level where individual carbon fiber geometry and electrolyte flow are directly resolved. The detailed geometry of the electrode is obtained using X-ray computed tomography (XCT) and calibrated against experimentally determined pore-scale characteristics (e.g., pore and fiber diameter, porosity, and surface area). The processed XCT data is then used as geometry input for modeling of the electrochemical processes in the VRFB. The flow of electrolyte through the pore space is modeled using the lattice Boltzmann method (LBM) while the finite volume method (FVM) is used to solve the coupled species and charge transport and predict the performance of the VRFB under various conditions. An electrochemical model using the Butler-Volmer equations is used to provide species and charge coupling at the surfaces of the carbon fibers. Results are obtained for the cell potential distribution, as well as local concentration, overpotential and current density profiles under galvanostatic discharge conditions. The cell performance is investigated as a function of the electrolyte flow rate and external drawing current. The model developed here provides a useful tool for building the structure-property-performance relationship of VRFB electrodes.
Automated categorization of drosophila learning and memory behaviors using video analysis
Authors:   , Reza Md. Alimoor , Breen David E.
Published: July 2021

The ability to study learning and memory behavior in living organisms has significantly increased our understanding of what genes affect this behavior, allowing for the rational design of therapeutics in diseases that affect cognition. The fruit fly, Drosophila melanogaster, is a well established model organism used to study the mechanisms of both learning and memory in vivo. The techniques used to assess this behavior in flies, while powerful, suffer from a lack of speed and quantification. The technical goal of this project is to create an automated method for characterizing this behavior in fruit flies by analyzing video of their movements. A method is developed to replace and improve a labor-intensive, subjective evaluation process with one that is automated, consistent and reproducible; thus allowing for robust, high-throughput analysis of large quantities of video data. The method includes identifying individual flies in a video, quantifying their size (which is correlated with their gender), and tracking their motion. Once the flies are identified and tracked, various geometric measures may be computed, for example distance between flies, their relative orientation, velocities and percentage of time the flies are in contact with each other. This data is computed for numerous experimental videos and produces high-dimensional feature vectors that quantify the behavior of the flies. Clustering techniques, e.g., k-means clustering, may then be applied to the feature vectors in order to computationally group each specimen by genotype. Our results show that we are able to automatically differentiate between normal and defective flies. We also generated a Computed Courtship Index (CCI), a computational equivalent of the existing Courtship Index (CI), and compared CCI with CI. These results demonstrate that our automated analysis provides a numerical scoring of fly behavior that is similar to the scoring produced by human observers.
Generator modeling for analog emulation of large scale power systems
Authors:   , Yakaski Jeffrey L. , Nwankpa Chikaodinaka Okechi Dike
Published: July 2021

This thesis proposes an approach to modeling generators for solving large-scale power systems in analog emulation. Analog emulation is becoming a computational alternative for power system analysis without the disadvantages of traditional digital computation methods. This approach allows for fast computation independent of system size and the development of accurate models. Circuit modeling and design issues of analog hardware are presented. The proposed generator model will focus on a second order circuit with suggestions for more advanced models. The design is capable of reconfiguring system parameters and emulating load flow calculations with other circuits, i.e. transmission lines and loads. This research focuses generator modeling and its steadystate solutions in traditional load flow studies.
The Model of American Philanthropy
Authors:   , Fuges Jennifer L.
Published: July 2021

A study on national and international philanthropy and development trends for non-profit organizations. Includes a comparison of non-profit organizations and how they fund-raise nationally and internationally. The thesis shows how the United States has developed its own model of philanthropy over time, and how other countries around the world are seeking to mimic this model, as their own cultural ministries are depleted and their government funding is cut.
Quantification of Hepatitis B Surface Antigen (HBsAg) in a Haimen City, China Cohort
Authors:   , Kim John , Evans Alison A.
Published: July 2021

Background: Liver cancer is the fifth most frequently diagnosed cancer, with hepatocellular carcinoma (HCC) constituting the majority of cases. Chronic hepatitis B (CHB) can incur a 25 to 30% lifetime risk for HCC. Along with demographic factors, serum hepatitis B surface antigen (HBsAg) quantitation may aid in HCC risk prediction among those with CHB. Objectives: A method to classify quantitative levels of HBsAg was developed to evaluate the association of demographic factors and other baseline exposure variables with HBsAg levels. HBsAg levels and known HCC risk factors were assessed to predict the risk for HCC mortality. Methods: This prospective study included participants with initial serum HBsAg quantity (n = 3,917) who were followed for HCC mortality from 1992 to 2010. Tertile distributions of sAg quantity were created and ordinal logistic regression was performed to assess explanatory risk variables against polytomous sAg group outcomes. Known risk factors for HCC were assessed with sAg group to predict HCC mortality using Cox proportional hazards. Results: This study demonstrated that participants with higher sAg quantity had a decreased risk for HCC. Among males, hepatitis history, family HCC history, and HBV DNA positivity were important indicators for HCC. Among females, hepatitis history was an important indicator for HCC. Conclusions: The rising incidence of HCC indicates a need to identify risk factors for HCC mortality in clinical practice. Among those with CHB, known demographic and medical history factors are associated with an increased risk of HCC. In addition, HBsAg quantitation may help predict HCC mortality among those with established CHB.
Effect of the Broad Autism Phenotype on Physical Activity and Weight Gain in Pregnancy
Authors:   , Bauer Jessica , Newschaffer Craig J.
Published: July 2021

Objectives: This study aims to provide insight on the potential role ASD-related genetic liability might have in confounding associations between prenatal maternal lifestyle variables and autism risk in subsequent Early Autism Risk Longitudinal Investigation (EARLI) analyses. In addition to examining parental broad autism phenotype as a confounder of risk factor associations, the questions of whether and how the broad autism phenotype influences behaviors related to healthy lifestyle is of interest and has been underexplored in the literature. Methods: EARLI is a prospective study examining genetic susceptibility and environmental risk factors for autism by following pregnant women who have a child diagnosed with autism spectrum disorder throughout their pregnancy and the new babies through age three. Several biological samples and surveys are collected, including the Social Responsiveness Scale (SRS), health behaviors pregnancy questionnaire, maternal interview, and maternal interview update, which were used to determine if there was an association between the maternal broad autism phenotype and lifestyle-related variables during pregnancy. Results: Adjusted analyses, though not statistically significant, showed that both weight gain and physical activity were positively associated with SRS. However, the association between SRS and weight gain varied by BMI class, with normal weight and overweight women gaining less weight and obese women gaining more weight as SRS scores increased. In addition, there were significant differences for weight gain and SRS when stratified by BMI and pregnancy complications as well as for physical activity and SRS when stratified by pregnancy complications. Analyses also demonstrated a possible interaction between pregnancy complications and physical activity and weight gain. Conclusions: There was little evidence of a strong association between the maternal broad autism phenotype and physical activity or weight gain during pregnancy. This means that genetic liability is probably not a confounder of the association between lifestyle and autism risk in the EARLI study.
Are file review-based SAVRY ratings of violence risk reliable?
Authors:   , Burl Jeffrey D. , DeMatteo David S.
Published: July 2021

Since its publication a decade ago, the Structured Assessment for Violence Risk in Youth (SAVRY) has gained acceptance as a strong predictor of future violence in adolescent populations. Clinicians scoring the SAVRY use their professional judgment to code a structured protocol of risk and protective factors based on clinical interviews, a review of the juvenile's records, and other sources of information. Much of the SAVRY validation research, however, has relied upon retrospective ratings obtained solely through file review. To date, no study has examined the reliability of file review-based SAVRY ratings. This study examined whether file-only SAVRY ratings are comparable to expert clinical ratings obtained through standard SAVRY administration procedures. Results indicate that file-only raters were unable to provide Summary Risk Ratings for 43% of the files and were unable to rate 53% of the SAVRY's individual items. The ratings that were coded by the file-only raters had low to moderate levels of agreement with the expert ratings. These results suggest that file-only SAVRY coding is not a reliable manner in which to obtain risk assessment ratings, but the current findings conflict with low rates of missing data in previous file-only SAVRY research. Further research should therefore be undertaken to provide greater clarity as to whether file-only SAVRY ratings of violence risk are reliable.
Decentralized and centralized supply chains with trade credit option
Authors:   , Du Ruo , Banerjee Avijit , Kim Seung Lae
Published: July 2021

The notion of a trade credit period is a common business practice, where a supplier allows a buyer a specified period to make a payment in full for a purchase made. The objective of this thesis is to explore the role of such a credit payment option in supply chain management. Towards this end, a two-echelon supply chain, consisting of a single supplier (e.g. manufacturer) and the cases of both a single and multiple buyers (e.g. retailers) is examined under decentralized (independent) and centralized (coordinated) decision making scenarios. The major emphasis of this research is limited to the case of a single product with price-sensitive deterministic, as well as stochastic market demand. The conditions under which a trade credit period should be offered and its appropriate length are determined from the supplier's perspective under the decentralized case. Under the centralized decision scenario, the efficacy of a trade credit policy as a supply chain coordination mechanism is thoroughly analyzed and guidelines for pricing, production and delivery decisions are developed. The concepts developed in this study are illustrated via a number of numerical examples, in conjunction with thorough sensitivity analyses involving some selected problem parameters. The major contribution of this thesis is that we incorporate the pricing and inventory issues in supply chains with an endogenous credit payment period. This is the first study that examines the efficacy of trade credit option as a coordination mechanism. We propose a coordination mechanism that coordinates the supply chain, when a trade credit by itself is not sufficient to serve such a purpose, while preserving the benefits of a trade credit option. Also, this study is the first to examine the issues concerning trade credit under price sensitive stochastic demand. Another first for this work is the exploration of the implications of a trade credit policy in supply chains consisting of multiple competing retailers. The effects of the extent of competition and the market size on trade credit policy are evaluated. Our analyses lead to some important practical implications, to serve as managerial guidelines.
Development of a multi-functional biopolymer scaffold for neural tissue engineering
Authors:   , Francis Nicola Louise , Wheatley Margaret A.
Published: July 2021

Spinal cord injury (SCI) affects approximately 270,000 people in the U.S., with approximately 12,000 new cases occurring every year. Several strategies have been investigated to enhance axonal regeneration after SCI, however, the resulting growth can be random and disorganized. Bioengineered scaffolds provide a physical substrate for the guidance of regenerating axons towards their targets, and can be produced by freeze casting. This technique involves the controlled directional solidification of an aqueous solution or suspension, resulting in a linearly aligned porous structure caused by ice templating. In this thesis, freeze casting was used to create novel porous chitosan-alginate (C/A) scaffolds with longitudinally aligned channels and a compressive modulus (5.08 ± 0.61 kPa) comparable to that of native spinal cord tissue. These C/A scaffolds supported the viability, attachment, and directionally oriented growth of chick dorsal root ganglia (DRG) neurites in vitro, with surface adsorptions of polycations and laminin promoting significantly longer neurite growth than the uncoated scaffolds (p<0.001). In order to integrate therapeutic biomolecules within the scaffolds for sustained release, alginate and chitosan microcapsules produced by spray drying were used to encapsulate brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), and the enzyme chondroitinase ABC (chABC) prior to scaffold incorporation. BDNF and NT-3 were released from the C/A scaffolds in a sustained manner for 8 weeks in vitro, while chABC was released for up to 35 days. However, up to 85% of biomolecules remained entrapped within the scaffold walls, due to limitation of diffusion by the scaffold wall mesh size. Release of bioactive chABC and neurotrophins from the multi-functional scaffolds promoted the growth of DRG neurites through an in vitro barrier of chondroitin sulfate proteoglycans, a main inhibitory component of the growth-inhibiting glial scar in the injured spinal cord. The present data suggest these multi-functional scaffolds are suitable for use and future testing in vivo as a combination strategy for spinal cord repair due to their ability to promote the directionally oriented growth of neurites and their ability to provide the sustained release of therapeutic bioactive molecules for the stimulation of axonal growth through the glial scar.