Margie and Bill Klesse College of Engineering and Integrated Design
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Browsing Margie and Bill Klesse College of Engineering and Integrated Design by Department "Biomedical Engineering and Chemical Engineering"
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Item A Review of Biomaterials and Associated Performance Metrics Analysis in Pre-Clinical Finite Element Model and in Implementation Stages for Total Hip Implant System(2022-10-13) Soliman, Md Mohiuddin; Chowdhury, Muhammad E. H.; Islam, Mohammad Tariqul; Musharavati, Farayi; Nabil, Mohammad; Hafizh, Muhammad; Khandakar, Amith; Mahmud, Sakib; Nezhad, Erfan Zal; Shuzan, Md Nazmul Islam; Abir, Farhan FuadTotal hip replacement (THR) is a common orthopedic surgery technique that helps thousands of individuals to live normal lives each year. A hip replacement replaces the shattered cartilage and bone with an implant. Most hip implants fail after 10–15 years. The material selection for the total hip implant systems is a major research field since it affects the mechanical and clinical performance of it. Stress shielding due to excessive contact stress, implant dislocation due to a large deformation, aseptic implant loosening due to the particle propagation of wear debris, decreased bone remodeling density due to the stress shielding, and adverse tissue responses due to material wear debris all contribute to the failure of hip implants. Recent research shows that pre-clinical computational finite element analysis (FEA) can be used to estimate four mechanical performance parameters of hip implants which are connected with distinct biomaterials: von Mises stress and deformation, micromotion, wear estimates, and implant fatigue. In vitro, in vivo, and clinical stages are utilized to determine the hip implant biocompatibility and the unfavorable local tissue reactions to different biomaterials during the implementation phase. This research summarizes and analyses the performance of the different biomaterials that are employed in total hip implant systems in the pre-clinical stage using FEA, as well as their performances in in vitro, in vivo, and in clinical studies, which will help researchers in gaining a better understanding of the prospects and challenges in this field.Item Antibacterial Layer-by-Layer Coatings for Medical Implants(2020-12-24) Escobar, Ane; Muzzio, Nicolas; Moya, Sergio EnriqueThe widespread occurrence of nosocomial infections and the emergence of new bacterial strands calls for the development of antibacterial coatings with localized antibacterial action that are capable of facing the challenges posed by increasing bacterial resistance to antibiotics. The Layer-by-Layer (LbL) technique, based on the alternating assembly of oppositely charged polyelectrolytes, can be applied for the non-covalent modification of multiple substrates, including medical implants. Polyelectrolyte multilayers fabricated by the LbL technique have been extensively researched for the development of antibacterial coatings as they can be loaded with antibiotics, antibacterial peptides, nanoparticles with bactericide action, in addition to being capable of restricting adhesion of bacteria to surfaces. In this review, the different approaches that apply LbL for antibacterial coatings, emphasizing those that can be applied for implant modification are presented.Item Assessing the Effectiveness of Problem-Based Learning Across Two Concrete Construction Courses(Gate Association for Teaching and Education, 2022-07-30) Torres, Anthony; Hu, Jiong; Sriraman, Vedaraman; Martinez Ortiz, Araceli; Membrillo-Hernández, JorgeThe goal of this study is to assess the effectiveness of a Problem-Based Learning (PBL) pedagogy that was implemented in two different concrete construction courses. Both courses are a part of an industry focused four-year undergraduate concrete degree program. One of the classes focused on concrete problems, diagnosis, and repair of existing concrete, while the other class focused on handling and management methods of various concrete mixtures. In both courses, a PBL pedagogy was implemented such that students were self-learning and discovering the knowledge through an action-research case study. The action-research case study was specific to the course outcomes relevant to each course, but were assessed similarly. A total of eight different assessment methods were implemented across both courses’ multiple times from 2012 – 2019. The results showed that the students are highly benefiting from the PBL pedagogy, which was indicated across all assessment methods. Each assessment technique provided a unique insight into student comprehension or benefits of the PBL pedagogy. The most beneficial assessment techniques were; pre- and post-student assessment, level of understanding and confidence, pre- and post-objective student assessment, and report assessment. These four assessment techniques provide both direct (objective) and indirect (subjective) assessment, while only requiring four total surveys.Item Assessing the Impact of Indiana Public Law 194 on Curbing the Concurrent Opioid Prescribing for Indiana Medicaid Enrollees(SAGE Publications, 2023-04-20) Vivas-Valencia, Carolina; Adams, Nicole; Griffin, Paul; Kong, NanBackground: Several US states have introduced legislation to support the legitimate medical use of opioids while limiting misuse and diversion. One concern which has been addressed through legislation is preventing individuals from seeking opioid prescriptions concurrently from multiple providers. However, the impact of this legislation on the incidence of patients receiving concurrent prescriptions remains relatively unexplored. This study examines this phenomenon based on claims data from Medicaid enrollees and the enactment of legislation in Indiana. Methods: Indiana Medicaid claims data over the period of January 2014 to December 2019 were used to determine the changes in the percentage of individuals receiving opioid prescriptions from multiple providers within a 30-day period, that is, concurrent opioid prescription (COP) individuals. Indiana Medicaid enrollees with a diagnosis of opioid use disorder (OUD) receiving opioid prescriptions, that is, the OUD-group, were identified and separated from the enrollees without a diagnosis but receiving opioid prescriptions, that is, the non-OUD group. The mean percentages of COP individuals (with or without an OUD diagnosis) within the subset of individuals that received opioid prescriptions were compared before and after the passage of Indiana Public Law 194. Results: There were 5336 who met the criteria of COP individuals, and 2050 of those were in the OUD-group. In either group, there was a significant difference in the change in percentages (slope) before and after Indiana Public Law 194 passed. In addition, there was a significant decrease in the mean percentage of COP individuals in the non-OUD group, while the difference was not significant in the OUD group. Conclusion: Our study suggests that Indiana Public Law 194 had a positive impact on curbing COP. This study is limited by the level of details available from claims data and suggests additional studies to evaluate prescription use and prescribing practices are warranted.Item Biomechanical Restoration Potential of Pentagalloyl Glucose after Arterial Extracellular Matrix Degeneration(2019-07-03) Patnaik, Sourav S.; Piskin, Senol; Pillalamarri, Narasimha Rao; Romero, Gabriela; Escobar, G. Patricia; Sprague, Eugene; Finol, Ender A.The objective of this study was to quantify pentagalloyl glucose (PGG) mediated biomechanical restoration of degenerated extracellular matrix (ECM). Planar biaxial tensile testing was performed for native (N), enzyme-treated (collagenase and elastase) (E), and PGG (P) treated porcine abdominal aorta specimens (n = 6 per group). An Ogden material model was fitted to the stress–strain data and finite element computational analyses of simulated native aorta and aneurysmal abdominal aorta were performed. The maximum tensile stress of the N group was higher than that in both E and P groups for both circumferential (43.78 ± 14.18 kPa vs. 10.03 ± 2.68 kPa vs. 13.85 ± 3.02 kPa; p = 0.0226) and longitudinal directions (33.89 ± 8.98 kPa vs. 9.04 ± 2.68 kPa vs. 14.69 ± 5.88 kPa; p = 0.0441). Tensile moduli in the circumferential direction was found to be in descending order as N > P > E (195.6 ± 58.72 kPa > 81.8 ± 22.76 kPa > 46.51 ± 15.04 kPa; p = 0.0314), whereas no significant differences were found in the longitudinal direction (p = 0.1607). PGG binds to the hydrophobic core of arterial tissues and the crosslinking of ECM fibers is one of the possible explanations for the recovery of biomechanical properties observed in this study. PGG is a beneficial polyphenol that can be potentially translated to clinical practice for preventing rupture of the aneurysmal arterial wall.Item Characterizing Conformational Change of a Thermoresponsive Polymeric Nanoparticle with Raman Spectroscopy(2023-06-19) Trabucco, Luis; Heath, Savannah; Shaw, Jonathan; McFadden, Sean; Wang, Xiaodu; Ye, Jing YongMolecular conformational changes in the collapsing and reswelling processes occurring during the phase transition at the lower critical solution temperature (LCST) of the polymer are not well understood. In this study, we characterized the conformational change of Poly(oligo(Ethylene Glycol) Methyl Ether Methacrylate)-144 (POEGMA-144) synthesized on silica nanoparticles using Raman spectroscopy and zeta potential measurements. Changes in distinct Raman peaks associated with the oligo(Ethylene Glycol) (OEG) side chains (1023, 1320, and 1499 cm−1) with respect to the methyl methacrylate (MMA) backbone (1608 cm−1) were observed and investigated under increasing and decreasing temperature profiles (34 ◦C to 50 ◦C) to evaluate the polymer collapse and reswelling around its LCST (42 ◦C). In contrast to the zeta potential measurements that monitor the change in surface charges as a whole during the phase transition, Raman spectroscopy provided more detailed information on vibrational modes of individual molecular moieties of the polymer in responding to the conformational change.Item CO2 Hydrogenation: Na Doping Promotes CO and Hydrocarbon Formation over Ru/m-ZrO2 at Elevated Pressures in Gas Phase Media(2023-03-24) Seuser, Grant; Staffel, Raechel; Hocaoglu, Yagmur; Upton, Gabriel F.; Garcia, Elijah S.; Cronauer, Donald C.; Kropf, A. Jeremy; Martinelli, Michela; Jacobs, GarySodium-promoted monoclinic zirconia supported ruthenium catalysts were tested for CO2 hydrogenation at 20 bar and a H2:CO2 ratio of 3:1. Although increasing sodium promotion, from 2.5% to 5% by weight, slightly decreased CO2 conversion (14% to 10%), it doubled the selectivity to both CO (~36% to ~71%) and chain growth products (~4% to ~8%) remarkably and reduced the methane selectivity by two-thirds (~60% to ~21%). For CO2 hydrogenation during in situ DRIFTS under atmospheric pressure, it was revealed that Na increases the catalyst basicity and suppresses the reactivity of Ru sites. Higher basicity facilitates CO2 adsorption, weakens the C–H bond of the formate intermediate promoting CO formation, and inhibits methanation occurring on ruthenium nanoparticle surfaces. The suppression of excessive hydrogenation increases the chain growth probability. Decelerated reduction during H2-TPR/TPR-MS and H2-TPR-EXAFS/XANES at the K-edge of ruthenium indicates that sodium is in contact with ruthenium. A comparison of the XANES spectra of unpromoted and Na-promoted catalysts after H2 reduction showed no evidence of a promoting effect involving electron charge transfer.Item Comprehensive Assessment of a Project Based Learning Application in a Project Management Course(Gate Association for Teaching and Education, 2021-05-22) Torres, Anthony; Sriraman, Vedaraman; Martinez Ortiz, AraceliThe focus of this study is to implement multiple assessment methods in order to comprehensively assess the impact of a Project Based Learning (PrBL) application in construction project management course. The assessment methods include various direct (objective) and indirect (subjective) evaluations methods. These methods included a pre and post questionnaire of student opinions, homework grades, in-class “clicker” quiz grades, overall project grades, embedded test question grades, a video lecture project, and short answer case study questions on exams from the Fall 2017 to Fall 2019 semesters. The data for this study was taken from the past six offerings of the same course, which was compared to a similar course in the same department. The analysis demonstrated that the students preferred both the use of an actual real-world project and the PrBL delivery method. The particular assessment methods that provided the most beneficial assessment were the embedded test questions and the case study section of the exam. The overall grade assessment method demonstrated an average of four percentage point increase in grades from previous offerings of the course and a similar course that does not include the PrBL pedagogy.Item A Comprehensive Model for Motivating and Preparing Under-represented Students, Educators and Parents in Science, Engineering, and Technology(American Society for Engineering Education, 2014-06-18) Martinez Ortiz, AraceliA comprehensive informal learning STEM outreach program for kindergarten through grade 4 (K-4) students is described along with the program’s theory of change and findings based on the participation of more than 200 urban minority students and their parents over a four-year period. This NSF-funded informal learning program was grounded in parental engagement theory of planned behavior and integrated both active-learning pedagogies and in-situ professional development for teachers. A unique age-appropriate science, engineering and technology integrated curriculum was delivered as a series of Saturday workshops set in a community science museum. Each year, cohorts of K‐3 African American and Hispanic students and their parents participated in eight 3-hour workshops comprised of student/parent sessions of hands-on science and engineering activities as well as separate parent awareness and development sessions in STEM education and technology skill development. The aim of this program has been to increase the participation of underrepresented groups in the science, technology, engineering, and mathematics (STEM) fields by attending to students early in the educational process. To accomplish this, the program has been guided by the following goals: to increase the knowledge, skills, and interest of K–3 students from underrepresented population groups in STEM fields; to increase parents’ knowledge and skills in science and engineering and their capacity to support their children in pursuing education and careers in these fields; and to increase the effectiveness of teachers in engaging students and parents in the Saturday science-related learning activities. Mixed methods research methodology has been used to measure the program’s contribution to the advancement of the program goals. Learning, motivational, and efficacy outcomes have been measured with pre and post student, teacher and parent survey instruments. This program has incorporated major findings of more than 10-years of research that suggests that improving children’s academic outcomes are much more effective when the family is actively engaged. This program has offered opportunities for parents to work along side their children; provided strategies promoting positive parental/child engagement; and provided ongoing training and professional development for project teachers. Young minority children have been exposed to African American, Latino, and women scientists and engineers through personal contact at special events, and via a featured program website section. Preliminary evaluation findings based on pre and post surveys, interviews, and observational data will be presented that indicate this program is helping parents and students persist in the program for multiple years and is motivating positive changes in student content understanding and career motivation.Item Considering the Effectiveness of Comprehensive Assessment and the Impact of PBL Implementation in a Concrete Industry Project Management Course(American Society for Engineering Education, 2016-06-26) Torres, Anthony; Sriraman, Vedaraman; Martinez Ortiz, AraceliThe objectives of this study were two-fold: first, to assess the effectiveness of using Project Based Learning (PrBL) pedagogy and second, to determine the efficacy of a comprehensive set of assessment methods from the standpoint of assessing learning in a PrBL implementation. The project used in this study incorporates actual, in-the-field projects that represent real-life scenarios that the students will encounter once they graduate. Various direct assessment methods were implemented in this study. These assessment methods included a pre and post questionnaire of student beliefs and opinions, homework grades, in-class ‘clicker’ quiz grades, overall project grades, embedded test question grades, a video lecture project, and short answer case study questions on exams. The data sets collected with these assessment methods were compared to data taken from the past two offerings of the same course and with data from a similar course taught by the same professor in the same department. The analysis reshowed that the students favored both the actual concrete construction project and the milestone deliverable method. The particular assessment methods that provided the most feedback were the embedded test questions and the case study section of the exam. Since students had to work with an individual real-world case study on the exam, the individual student’s effort, understanding, and ability to solve technical problems from the milestone project were quantified through the exam. The overall grade assessment method revealed an average of 4.5 percentage point increase in grades from past offerings of the course and a similar course that does not include the PrBL pedagogy.Item Design and Development of Augmented Reality Engineering Expeditions - Innovations in Online Engineering Education(American Society for Engineering Education, 2021-03-24) Martinez Ortiz, Araceli; Spencer, Bobbi J.; Rojas, CindyThis paper presents a framework for the design of augmented reality expeditions in engineering education settings to motivate student learning of engineering fundamentals and careers. The impact of social distancing has been significant for students of all ages and there is a great need for additional and creative online learning resources. The engineering field has an opportunity to not only motivate and support student learning, but to do so by featuring the very innovative nature of engineering as a tool to develop those experiences. A case study regarding the development of NASA-themed aeronautics virtual tours and virtual field trips highlights the capabilities of various software technologies and offers design considerations. The three developed virtual expeditions serve as an opportunity to engage and educate high school and university students. A research plan to collect student feedback on these experiences is also presented.Item Design and Performance Evaluation of a Novel Spiral Head-Stem Trunnion for Hip Implants Using Finite Element Analysis(2023-02-09) Soliman, Md Mohiuddin; Chowdhury, Muhammad E. H.; Islam, Mohammad Tariqul; Musharavati, Farayi; Mahmud, Sakib; Hafizh, Muhammad; Ayari, Mohamed Arselene; Khandakar, Amith; Alam, Mohammad Kaosar; Nezhad, Erfan ZalWith an expectation of an increased number of revision surgeries and patients receiving orthopedic implants in the coming years, the focus of joint replacement research needs to be on improving the mechanical properties of implants. Head-stem trunnion fixation provides superior load support and implant stability. Fretting wear is formed at the trunnion because of the dynamic load activities of patients, and this eventually causes the total hip implant system to fail. To optimize the design, multiple experiments with various trunnion geometries have been performed by researchers to examine the wear rate and associated mechanical performance characteristics of the existing head-stem trunnion. The objective of this work is to quantify and evaluate the performance parameters of smooth and novel spiral head-stem trunnion types under dynamic loading situations. This study proposes a finite element method for estimating head-stem trunnion performance characteristics, namely contact pressure and sliding distance, for both trunnion types under walking and jogging dynamic loading conditions. The wear rate for both trunnion types was computed using the Archard wear model for a standard number of gait cycles. The experimental results indicated that the spiral trunnion with a uniform contact pressure distribution achieved more fixation than the smooth trunnion. However, the average contact pressure distribution was nearly the same for both trunnion types. The maximum and average sliding distances were both shorter for the spiral trunnion; hence, the summed sliding distance was approximately 10% shorter for spiral trunnions than that of the smooth trunnion over a complete gait cycle. Owing to a lower sliding ability, hip implants with spiral trunnions achieved more stability than those with smooth trunnions. The anticipated wear rate for spiral trunnions was 0.039 mm3, which was approximately 10% lower than the smooth trunnion wear rate of 0.048 mm3 per million loading cycles. The spiral trunnion achieved superior fixation stability with a shorter sliding distance and a lower wear rate than the smooth trunnion; therefore, the spiral trunnion can be recommended for future hip implant systems.Item Development And Implementation Of Challenge Based Instruction In Statics And Dynamics(American Society for Engineering Education, 2010-06-20) Freeman, Robert; Vasquez, Horacio; Knecht, Martin; Martin, Taylor; Fuentes, Arturo; Walker, Joan; Martinez Ortiz, AraceliThis paper discusses challenge-based instructional (CBI) materials developed for courses in Statics and Dynamics. This effort is a component of a funded College Cost Reduction and Access Act (CCRAA) grant from the Department of Education, and focuses on student retention and development of adaptive expertise. Studies have shown that minority science, technology, engineering, and math (STEM) students leave STEM undergraduate fields in part due to lack of real world connections to their classroom learning experiences. Furthermore, in STEM fields the conventional approach is to teach for efficiency first and for innovation only in the latter years of the curriculum. This focus on efficiency first can actually stifle attempts at innovation in later courses. Our response to these issues is to change the way we teach. CBI, a form of inquiry based learning, can be simply thought of as teaching backwards. In this approach, a challenge is presented first, and the supporting theory (required to solve the challenge) second. Our implementation of CBI is built around the How People Learn (HPL) framework for effective learning environments and is realized and anchored by the STAR Legacy Cycle, as developed and fostered by the VaNTH NSF ERC for Bioengineering Educational Technologies. The developed materials are a result of collaboration between faculty members at the University of Texas-Pan American (UTPA) and South Texas College (STC), a two year Hispanic Serving Institution (HSI).Item Early Internships for Engineering Technology Student Retention: A Pilot Study(American Society for Engineering Education, 2016-06-26) Sriraman, Vedaraman; Spencer, Bobbi J.; Talley, Kimberly Grau; Martinez Ortiz, AraceliResearch in engineering technology major retention suggests that early internships present an outstanding opportunity for freshman and sophomore students to engage, socialize and learn in communities of practice and to “discover” the link between theory and practice early in their academic tenure, leading to a consequent improvement in retention rates. At xxxx State University, the traditional senior level capstone internship program was reengineered and converted into a sophomore level program with minimal prerequisites so as to enable sophomore level engineering technology students to participate early in the internships, explore their majors and undergo experiential learning in the world of practice in their chosen disciplines. The motivation for this project came from onsite internship industry interviews and our industrial advisory boards which strongly suggested that early, “immersion” type industrial experiences would prepare students to become better learners. This conversion coincided with the strategic imperatives that stemmed from a university wide second year STEM major retention effort. This latter effort culminated in a four year NSF funded project, of which the early internships are a module. This paper describes the internship program reengineering effort, the details of the early internship program implementation and aspects of how the program is facilitating the assessment of student learning outcomes for ABET and other accreditation processes. The paper concludes with preliminary results that were harvested from the pilot implementation in Summer 2015 and with directions for future work.Item Editorial: Cobalt and Iron Catalysis(2019-12-27) Shafer, Wilson D.; Jacobs, GaryCobalt and iron have long history of importance in the field of catalysis that continues to this day. Currently, both are prevalent metals in a multitude of catalytic processes: [...]Item Effect of the Interactions between Oppositely Charged Cellulose Nanocrystals (CNCs) and Chitin Nanocrystals (ChNCs) on the Enhanced Stability of Soybean Oil-in-Water Emulsions(2022-09-26) Parajuli, Sanjiv; Hasan, Mohammad Jahid; Ureña-Benavides, Esteban E.Chitin nanocrystals (ChNCs) and cellulose nanocrystals (CNCs) have been recently used to stabilize emulsions; however, they generally require significant amounts of salt, limiting their applicability in food products. In this study, we developed nanoconjugates by mixing positively charged ChNCs and negatively charged CNCs at various ChNC:CNC mass ratios (2:1, 1:1, and 1:2), and utilized them in stabilizing soybean oil–water Pickering emulsions with minimal use of NaCl salt (20 mM) and nanoparticle (NP) concentrations below 1 wt%. The nanoconjugates stabilized the emulsions better than individual CNC or ChNC in terms of a reduced drop growth and less creaming. Oppositely charged CNC and ChNC neutralized each other when their mass ratio was 1:1, leading to significant flocculation in the absence of salt at pH 6. Raman spectroscopy provided evidence for electrostatic interactions between the ChNCs and CNCs, and generated maps suggesting an assembly of ChNC bundles of micron-scale lengths intercalated by similar-size areas predominantly composed of CNC. The previous measurements, in combination with contact angles on nanoparticle films, suggested that the conjugates preferentially exposed the hydrophobic crystalline planes of CNCs and ChNCs at a 1:1 mass ratio, which was also the best ratio at stabilizing soybean oil–water Pickering emulsions.Item Engaging Students in Sustainability Education and Awareness of Green Engineering Design and Careers through a Pre-Engineering Program(American Society for Engineering Education, 2015-06-17) Martinez Ortiz, Araceli; Asiabanpour, Bahram; Aslan, Semih; Jimenez, Jesus Alejandro; Kim, Yoo-Jae; Salamy, HassanA framework for an active learning summer program for middle school students is presented along with survey instruments and pre and post program data regarding student attitudes and awareness of sustainable design issues and career motivation in the field. This summer program was designed to attract students, especially from underrepresented groups, into early motivating experiences in the engineering fields and to increase their awareness of concepts and careers in renewable energy, and green engineering design principles and technologies. Twenty-four students from a low social economic school district were provided the opportunity to experience many state of the art engineering technologies at the university’s school of engineering and to learn from a diverse group of knowledgeable mentoring faculty. In the week-long program, students were involved in hands-on engineering and renewable energy activities appropriate to their age and knowledge. Topics covered included: the engineering design process, CAD solid modeling, 3D Printing and water jet cutting, hands-on assembly, renewable energy resources for homes, sustainable site selection, and water efficiency principles. Using project-based learning, student teams participated as designers of their own green home models by integrating their learning of renewable energy use, conservation practices, and appropriate design and material selection. Pre and post surveys revealed increases in student awareness of general engineering and renewable energy concepts as well as increased interest in pursuing engineering careers.Item Engineering Functional Vascularized Beige Adipose Tissue from Microvascular Fragments of Models of Healthy and Type II Diabetes Conditions(SAGE Publications, 2022-06-24) Acosta, Francisca M.; Stojkova, Katerina; Zhang, Jingruo; Garcia Huitron, Eric Ivan; Jiang, Jean X.; Rathbone, Christopher R.; Brey, Eric M.Engineered beige adipose tissues could be used for screening therapeutic strategies or as a direct treatment for obesity and metabolic disease. Microvascular fragments are vessel structures that can be directly isolated from adipose tissue and may contain cells capable of differentiation into thermogenic, or beige, adipocytes. In this study, culture conditions were investigated to engineer three-dimensional, vascularized functional beige adipose tissue using microvascular fragments isolated from both healthy animals and a model of type II diabetes (T2D). Vascularized beige adipose tissues were engineered and exhibited increased expression of beige adipose markers, enhanced function, and improved cellular respiration. While microvascular fragments isolated from both lean and diabetic models were able to generate functional tissues, differences were observed in regard to vessel assembly and tissue function. This study introduces an approach that could be employed to engineer vascularized beige adipose tissues from a single, potentially autologous source of cells.Item Engineering Outreach: Ambassador Girls Empowering Girls in the Field(American Society for Engineering Education, 2020-06-22) Hug, Sarah; Eyerman, Suzanne; Fletcher, Trina L.; Martinez Ortiz, Araceli; Soltys, Michael A.The EngineerGirl Ambassadors program is designed to recognize, support, and promote high school girls who intend to give back to their community through youth outreach activities. In its second year, the program is an extension of the National Academy of Engineering’s “EngineerGirl” online community, established in 2001. EngineerGirl Ambassadors apply in the spring for acceptance to the program in the fall and attend the Society of Women in Engineers (SWE) conference with a local adult sponsor to participate in professional development. The Ambassadors program emphasizes the “Five Cs” of youth development: confidence, connection, competence, character, and caring/compassion. Trainings for the Ambassadors relate to multiple aspects of informal STEM education, including recruitment, activity selection, problem based learning, and effective questioning. Ambassadors also attend the traditional SWE events, such as keynote talks, the outreach expo, and programming centered on developing leadership qualities. High school Ambassadors develop programming, partner with community leaders such as school administrators, librarians, and nonprofit leaders to secure venues for their youth-focused activities and receive a modest sum to purchase materials for programs. The Ambassadors recruit participants with an emphasis on middle school students who are underrepresented in engineering (female students, as well as students who identify as Native American/Pacific Islander, African American/black, and LatinX/Hispanic), utilizing school and community connections to reach middle school students (e.g., asking former middle school science teachers if they can recruit in their classrooms). Upon the completion of their programs, they assist in survey data collection for the evaluation team, and a selection of participants are observed. Ambassadors are encouraged to return to the SWE conference the following year through SWE-funded awards, so they can serve as role models to newly selected Ambassadors. Program evaluation includes participant observation, survey data collection and analysis of Ambassador’s participants, interviews with Ambassadors and sponsors, and (in year two) surveys of sponsors and Ambassadors directly following the SWE conference experience. Ambassadors described increased confidence in engineering, and stronger connection to a network of like-minded young women. Results indicate youth attending outreach activities run by Ambassadors increased their interest in engineering (88%), know more about what engineers do (91%), know the engineering design process (84%), and feel increased belonging to a group interested in the field (87%). Program formative and summative evaluation uncovered multiple challenges and worked with the program director, staff, and the steering committee to address challenges, such as coordinating travel with youth participants, selecting with equity and diversity in mind, balancing innovation with “field tested” outreach programs, and coaching at a distance throughout the academic year. Challenges and successes will be addressed at length in the full paper, for example, the authors will describe the rubric development and refinement process in detail, including how changes may have supported a focus on equity in the selection process.Item Evaluating the Performance of a Nonelectronic, Versatile Oxygenating Perfusion System across Viscosities Representative of Clinical Perfusion Solutions Used for Organ Preservation(2022-12-20) Gonzalez, Jose M.; Villarreal, Carorina; Fasci, Anjelyka; Di Rocco, David; Salazar, Sophia; Khalil, Anis; Wearden, Brandt; Oseghale, Jessica; Garcia, Mariana; Portillo, Daniel J.; Hood, R. LyleIntroduction: On the United States' Organ Transplantation Waitlist, approximately 17 people die each day waiting for an organ. The situation continues to deteriorate as the discrepancy between harvested organs and the number of patients in need is increasing. Static cold storage is the clinical standard method for preserving a harvested organ but is associated with several drawbacks. Machine perfusion of an organ has been shown to improve preservation quality as well as preservation time over static cold storage. While there are machine perfusion devices clinically available, they are costly and limited to specific organs and preservation solutions. This study presents a versatile oxygenating perfusion system (VOPS) that supplies oxygen and pulsatile perfusion. Materials and Methods: Experiments evaluated the system's performance with a human kidney mimicking hydraulic analog using multiple compressed oxygen supply pressures and aqueous solutions with viscosities ranging from 1 to 6.5 cP, which simulated viscosities of commonly used organ preservation solutions. Results and Conclusions: The VOPS produced mean flow rates ranging from 0.6 to 28.2 mL/min and perfusion pressures from 4.8 to 96.8 mmHg, which successfully achieved the desired perfusion parameters for human kidneys. This work provides evidence that the VOPS described herein has the versatility to perfuse organs using many of the clinically available preservation solutions.