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With the increasing focus on developing environmentally benign electronic packages, lead-free solder alloys have received a great deal of attention. Mishandling of packages, during manufacture, assembly, or by the user may cause failure of solder joint. A fundamental understanding of the behavior of lead-free solders under mechanical shock conditions is

With the increasing focus on developing environmentally benign electronic packages, lead-free solder alloys have received a great deal of attention. Mishandling of packages, during manufacture, assembly, or by the user may cause failure of solder joint. A fundamental understanding of the behavior of lead-free solders under mechanical shock conditions is lacking. Reliable experimental and numerical analysis of lead-free solder joints in the intermediate strain rate regime need to be investigated. This dissertation mainly focuses on exploring the mechanical shock behavior of lead-free tin-rich solder alloys via multiscale modeling and numerical simulations. First, the macroscopic stress/strain behaviors of three bulk lead-free tin-rich solders were tested over a range of strain rates from 0.001/s to 30/s. Finite element analysis was conducted to determine appropriate specimen geometry that could reach a homogeneous stress/strain field and a relatively high strain rate. A novel self-consistent true stress correction method is developed to compensate the inaccuracy caused by the triaxial stress state at the post-necking stage. Then the material property of micron-scale intermetallic was examined by micro-compression test. The accuracy of this measure is systematically validated by finite element analysis, and empirical adjustments are provided. Moreover, the interfacial property of the solder/intermetallic interface is investigated, and a continuum traction-separation law of this interface is developed from an atomistic-based cohesive element method. The macroscopic stress/strain relation and microstructural properties are combined together to form a multiscale material behavior via a stochastic approach for both solder and intermetallic. As a result, solder is modeled by porous plasticity with random voids, and intermetallic is characterized as brittle material with random vulnerable region. Thereafter, the porous plasticity fracture of the solders and the brittle fracture of the intermetallics are coupled together in one finite element model. Finally, this study yields a multiscale model to understand and predict the mechanical shock behavior of lead-free tin-rich solder joints. Different fracture patterns are observed for various strain rates and/or intermetallic thicknesses. The predictions have a good agreement with the theory and experiments.
ContributorsFei, Huiyang (Author) / Jiang, Hanqing (Thesis advisor) / Chawla, Nikhilesh (Thesis advisor) / Tasooji, Amaneh (Committee member) / Mobasher, Barzin (Committee member) / Rajan, Subramaniam D. (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Concrete columns constitute the fundamental supports of buildings, bridges, and various other infrastructures, and their failure could lead to the collapse of the entire structure. As such, great effort goes into improving the fire resistance of such columns. In a time sensitive fire situation, a delay in the failure of

Concrete columns constitute the fundamental supports of buildings, bridges, and various other infrastructures, and their failure could lead to the collapse of the entire structure. As such, great effort goes into improving the fire resistance of such columns. In a time sensitive fire situation, a delay in the failure of critical load bearing structures can lead to an increase in time allowed for the evacuation of occupants, recovery of property, and access to the fire. Much work has been done in improving the structural performance of concrete including reducing column sizes and providing a safer structure. As a result, high-strength (HS) concrete has been developed to fulfill the needs of such improvements. HS concrete varies from normal-strength (NS) concrete in that it has a higher stiffness, lower permeability and larger durability. This, unfortunately, has resulted in poor performance under fire. The lower permeability allows for water vapor to build up causing HS concrete to suffer from explosive spalling under rapid heating. In addition, the coefficient of thermal expansion (CTE) of HS concrete is lower than that of NS concrete. In this study, the effects of introducing a region of crumb rubber concrete into a steel-reinforced concrete column were analyzed. The inclusion of crumb rubber concrete into a column will greatly increase the thermal resistivity of the overall column, leading to a reduction in core temperature as well as the rate at which the column is heated. Different cases were analyzed while varying the positioning of the crumb-rubber region to characterize the effect of position on the improvement of fire resistance. Computer simulated finite element analysis was used to calculate the temperature and strain distribution with time across the column's cross-sectional area with specific interest in the steel - concrete region. Of the several cases which were investigated, it was found that the improvement of time before failure ranged between 32 to 45 minutes.
ContributorsZiadeh, Bassam Mohammed (Author) / Phelan, Patrick (Thesis advisor) / Kaloush, Kamil (Thesis advisor) / Jiang, Hanqing (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Pb-free solders are used as interconnects in various levels of micro-electronic packaging. Reliability of these interconnects is very critical for the performance of the package. One of the main factors affecting the reliability of solder joints is the presence of porosity which is introduced during processing of the joints. In

Pb-free solders are used as interconnects in various levels of micro-electronic packaging. Reliability of these interconnects is very critical for the performance of the package. One of the main factors affecting the reliability of solder joints is the presence of porosity which is introduced during processing of the joints. In this thesis, the effect of such porosity on the deformation behavior and eventual failure of the joints is studied using Finite Element (FE) modeling technique. A 3D model obtained by reconstruction of x-ray tomographic image data is used as input for FE analysis to simulate shear deformation and eventual failure of the joint using ductile damage model. The modeling was done in ABAQUS (v 6.10). The FE model predictions are validated with experimental results by comparing the deformation of the pores and the crack path as predicted by the model with the experimentally observed deformation and failure pattern. To understand the influence of size, shape, and distribution of pores on the mechanical behavior of the joint four different solder joints with varying degrees of porosity are modeled using the validated FE model. The validation technique mentioned above enables comparison of the simulated and actual deformation only. A more robust way of validating the FE model would be to compare the strain distribution in the joint as predicted by the model and as observed experimentally. In this study, to enable visualization of the experimental strain for the 3D microstructure obtained from tomography, a three dimensional digital image correlation (3D DIC) code has been implemented in MATLAB (MathWorks Inc). This developed 3D DIC code can be used as another tool to verify the numerical model predictions. The capability of the developed code in measuring local displacement and strain is demonstrated by considering a test case.
ContributorsJakkali, Vaidehi (Author) / Chawla, Nikhilesh K (Thesis advisor) / Jiang, Hanqing (Committee member) / Solanki, Kiran (Committee member) / Arizona State University (Publisher)
Created2011
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Description

This case study describes an adult patient whose brachial plexus injury was treated with various modalities and exercise. The participant of this study was a 76 year old female who sustained a brachial plexus injury during an elective reverse total shoulder arthroplasty. The initial evaluation reported only passive range of

This case study describes an adult patient whose brachial plexus injury was treated with various modalities and exercise. The participant of this study was a 76 year old female who sustained a brachial plexus injury during an elective reverse total shoulder arthroplasty. The initial evaluation reported only passive range of motion with 90 degrees shoulder flexion, 85 degrees abduction, and 30 degrees external rotation. Muscle testing yielded significantly limited wrist and digit extension strength. Testing of sensation found diminished protective sensation along the median nerve distribution, including the thumb, index finger, and middle finger. Occupational therapy was initiated for postoperative treatment of the shoulder as well as treatment of the brachial plexus palsy. Therapy consisted of static splinting for healing structures and sensory reeducation through massage, finding objects with the eyes occluded, and fluidotherapy. Additionally, various exercises and modalities for improving motion and strength were initiated, including proprioceptive neuromuscular reeducation, passive/active assist/active exercises, dynamic splinting, muscle stimulation, kinesio tape, functional activities, and tendon glides. After five months, active range of motion in the shoulder, elbow, and wrist was finally achieved and median nerve sensation had improved. After nine months, elbow motion was within normal limits and wrist motion had significantly improved. Upon muscle testing, the elbow, forearm, wrist, and hand had made significant gains in strength. However, shoulder strength and motion was still limited. Overall, treatment made a significant improvement in the patient’s functionality.

ContributorsMorlock, Callista (Author) / Ramos, Christopher (Thesis director) / Thomas, Karen (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Within the pediatric hospitalization experience, fear and anxiety are two emotions commonly felt by children of all ages. Hospitalized children can greatly benefit from interventions designed to help them cope with these emotions throughout their medical experiences. This study draws on each of our clinical experiences as volunteers at Phoenix

Within the pediatric hospitalization experience, fear and anxiety are two emotions commonly felt by children of all ages. Hospitalized children can greatly benefit from interventions designed to help them cope with these emotions throughout their medical experiences. This study draws on each of our clinical experiences as volunteers at Phoenix Children’s Hospital, and uses a qualitative analysis of three semi-structured interviews with currently employed Child Life Specialists to understand and analyze the use of medical play, a form of play intervention with a medical theme or medical equipment. We explore the goals and benefits of medical play for hospitalized pediatric patients, the process of using medical play as an intervention, including the activity design process, the assessments and adjustments made throughout the child’s hospitalization, and the considerations and limitations to implementing medical play activities. Ultimately, we found that the element of fun that defines play can be channeled into medical play activities implemented by skilled Child Life Specialists, who are experts in their field, in clinical settings to promote several different and beneficial goals, including pediatric patient coping.

ContributorsGarciapena, Danae (Co-author) / Aguiar, Lara (Co-author) / Loebenberg, Abby (Thesis director) / Swanson, Jodi (Committee member) / College of Health Solutions (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Background: The purpose of this study was to assess the efficacy of a lifestyle intervention on cardiorespiratory fitness in Latino youth with obesity and prediabetes. <br/>Methods: Participants (n=50) in this study were taken from a larger randomized controlled trial (n=180, BMI ≥ 95th percentile). Youth participated in a 6-month lifestyle

Background: The purpose of this study was to assess the efficacy of a lifestyle intervention on cardiorespiratory fitness in Latino youth with obesity and prediabetes. <br/>Methods: Participants (n=50) in this study were taken from a larger randomized controlled trial (n=180, BMI ≥ 95th percentile). Youth participated in a 6-month lifestyle intervention that included physical activity (60 minutes, 3x/week) and nutrition and wellness classes (60 minutes, 1x/week) delivered to families at the Lincoln Family YMCA in Downtown Phoenix. The primary outcome was cardiorespiratory fitness measured at baseline and post-intervention.<br/>Results: The mean BMI for the sample was 33.17 ± 4.54 kg/m2, which put the participants in the 98.4th percentile. At baseline, the mean VO2max was 2737.02 ± 488.89 mL/min. The mean relative VO2max was 30.65 ± 3.87 mL/kg/min. VO2max values significantly increased from baseline to post-intervention (2737.022 ± 483.977 mL/min vs 2932.654 ± 96.062 mL/min, p<0.001). <br/>Conclusion: Culturally-grounded, family-focused lifestyle interventions are a promising approach for improving cardiorespiratory fitness in high-risk youth at risk for diabetes.

ContributorsEstrada, Lourdes Alexa (Author) / Shaibi, Gabriel (Thesis director) / Peña, Armando (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

The following paper explores the various effects of stress on the endocrine system. Many understand that being stressed can jeopardize maintaining adequate health, but what specifically happens when humans are stressed? Why does stress affect human health? This paper delves into background information, previous research, and the depths to which

The following paper explores the various effects of stress on the endocrine system. Many understand that being stressed can jeopardize maintaining adequate health, but what specifically happens when humans are stressed? Why does stress affect human health? This paper delves into background information, previous research, and the depths to which stress negatively affects the body. The effects stress has on the endocrine system, specifically on the hypothalamic-pituitary-thyroid axis (HPT) and hypothalamic-pituitary-adrenal axis (HPA), is discussed, and additionally, at home de-stressing methods are researched. The study included a set of participants at Arizona State University. The method took place over the course of 2 weeks: one normal week, and the other with the implementation of a de-stressing method. The normal week involved the participants living their daily lives with the addition of a stress-measuring survey, while the second week involved implementing a de-stressing method and stress-measuring survey. The purpose of this study was to discover if there was a correlation between performing these relaxation activities and decreasing stress levels in ASU students. The results found that students reported they felt more relaxed and calm after the activities. Overall, this thesis provides information and first hand research on the effects of stress and stress-reducing activities and discusses the importance of maintaining lower stress levels throughout everyday life.

ContributorsWeissmann, Megan Diane (Co-author) / Gebara, Nayla (Co-author) / Don, Rachael (Thesis director) / Irving, Andrea (Committee member) / Kizer, Elizabeth (Committee member) / College of Health Solutions (Contributor) / Edson College of Nursing and Health Innovation (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

The purpose of this Barrett Thesis Project is to review the existing literature on ACL injuries specifically regarding their risk factors, prevention, and recovery options. The content of the review has been placed into four sections: physiological factors, biomechanical factors, surgery and recovery factors, as well as training factors.

The purpose of this Barrett Thesis Project is to review the existing literature on ACL injuries specifically regarding their risk factors, prevention, and recovery options. The content of the review has been placed into four sections: physiological factors, biomechanical factors, surgery and recovery factors, as well as training factors. Physiological factors look at static structures and their impact on ACL injuries, more specifically, the role that variations on physical structure values can have on injury incidence. Biomechanical factors focus on the ways that movement can contribute to injury and the ways that incorrect movement or unanticipated movement can have on the structures of the knee. Surgery and recovery factors look at surgical techniques that have been used to correct ACL injuries and the details of their function as well as certain surgical techniques that have differing rates of success and how they can impact re-injury and rehabilitation rates. Finally, training factors analyze techniques that can be used in both pre-injury or post-injury situations therefore, this section looks at the ways that training can minimize re-injury as well as work towards preventing the initial injury. Overall, this research review looks at how these factors come together to contribute to an ACL injury and the ways that injury incidence can be minimized. Risk factors come together in order to create an undesirable situation in which the ACL ligament ruptures. These risk factors are either physiological or biomechanical in nature. As a result of injury, certain surgical techniques can be used that impact the success of a patient. Evidence for the benefit of training factors can then be applied in order to reduce injury risk or prevent future injuries.

ContributorsIsrael, Kyle (Co-author) / Fang, Charles (Co-author) / Ramos, Christopher (Thesis director) / Larson, David (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Background: The US population faces a continual increase in obesity prevalence, raising health concerns due to associated comorbidities ranked as leading causes of preventable, premature death world-wide. Scientists have found a link between obesity-associated conditions and oxidative stress (OS). To date, renewed interest in the effectiveness of dietary regimens in

Background: The US population faces a continual increase in obesity prevalence, raising health concerns due to associated comorbidities ranked as leading causes of preventable, premature death world-wide. Scientists have found a link between obesity-associated conditions and oxidative stress (OS). To date, renewed interest in the effectiveness of dietary regimens in decreasing body weight is a popular research topic. Intermittent fasting (IF) is a popular and promising weight management strategy. To date, there have been no systematic reviews examining whether IF can reduce oxidative stress in overweight/obese adults. <br/><br/>Objective: Conduct a systematic review to evaluate the effects of intermittent fasting (IF) regimens on circulating markers of oxidative stress in overweight/obese adults compared to continuous calorie restriction (CR). <br/><br/>Methods: Databases PubMed, SCOPUS, ProQuest, and Cochrane were searched on February 21, 2021 for eligible articles limiting selection to those in the English language. Predefined search terms and restrictions were applied by two of the authors conducting the search. References from articles generated were also considered. Selected articles were limited to randomized controlled trials (RCTs) and human trials evaluating the effects of intermittent fasting (IF) dietary regimens in comparison to continuous calorie restriction (CR). Study populations considered were limited to those within the range of 18-65 years having a body mass index (BMI) of ≥25 kg/m2 and in otherwise generally good health with the absence of pre-existing acute or chronic conditions. The Academy of Nutrition and Dietetics Evidence Analysis Library Quality Rating Worksheet was used to assess the methodological quality of each of the studies and the Academy of Nutrition and Dietetics Grade Definitions and Conclusion Grading Table were used to appraise the quality of evidence.<br/><br/>Results: Six articles met eligibility criteria and were included in this review. Cumulatively 355 overweight/obese participants were assessed. Quality ratings performed by two of the authors revealed a high-quality rating for all six of the articles. One of the articles reported a significant IF associated difference in circulating 8-isoprostane concentrations and another article reported a significant decrease in circulating oxidative lipoproteins concentrations. The remaining articles showed no significant difference on OS markers following IF. <br/><br/>Conclusions: Based on the six articles included in this systematic review, IF was concluded to have limited impact on reducing circulating markers of OS in overweight/obese adults. Overall, the evidence was heterogeneous in relation to IF interventions and outcomes precluding a meta-analysis. Consequently, evidence to make dietary recommendations for reducing oxidative stress with IF interventions is insufficient at this point.

ContributorsMcevoy, Carissa Nicole (Author) / Sweazea, Karen (Thesis director) / Sears, Dorothy (Committee member) / Mohr, Alex (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

In my undergraduate honors thesis, I strive to convey my idea that dance is more than just movement, it’s one of the many artistic tools used to express emotions; which therefore has the power to storytell without words. It is my hope to create a captivating form of art that

In my undergraduate honors thesis, I strive to convey my idea that dance is more than just movement, it’s one of the many artistic tools used to express emotions; which therefore has the power to storytell without words. It is my hope to create a captivating form of art that you not only view, but can interact and interpret.

ContributorsSawant, Sarika (Author) / Roses-Thema, Cynthia (Thesis director) / Sulikowski, James (Committee member) / College of Health Solutions (Contributor) / School of Music, Dance and Theatre (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05