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Characterization And Enhancement Of Fatigue And Fracture Properties In Thermoplastic Fff Parts Using In-Situ Annealing, Manjarik Mrinal

Mechanical and Aerospace Engineering Dissertations

Fused filament fabrication (FFF) show high anisotropy and reduced mechanical properties as compared to conventional manufacturing techniques. This happens due to the poor interlaminar bonding between the layers, as a result of premature halt of bond healing process. Previous research works show multiple approaches to improve the bond quality to enhance the mechanical properties of FFF parts, however these are complex and expensive techniques. In this work a novel print head assembly is presented to offer a simple and effective solution by applying a thermal field to the part as it is being printed to preheat the previously deposited layer, …

Prediction Of Solder Joint Fatigue Life Of Photonic Package Using ?-? Materials, Ojas Tyagi

Mechanical and Aerospace Engineering Theses

Fatigue life prediction has become very important factor in reliability of any electronic components to withstand extreme thermal stresses in industrial standard. Hence, photonic packages are widely used in telecommunication and computer applications. The primary focus of this study is to determine the thermal cycles to crack initiation of solder bump used in laser array waferboard for telecommunication applications. This includes GaAs Laser chip on waferboard and Si substrate with pure Indium solder balls in between. Indium has proved higher fatigue life in various experimental studies in the field of reliability and lead-free material. Therefore, a solder ball was designed …

Assessing Mechanical Performance Of Dissimilar Steel Systems Made Via Wire-Arc Additive Manufacturing, Obed Daniel Acevedo

Masters Theses

Hot stamping is part of a specific type of metalworking procedure widely used in the automotive industry. This research seeks to help make hot stamp tooling component production more cost-effective by using large-scale additive manufacturing. Additive manufacturing can produce dissimilar steel components that can be more cost-effective and time-efficient and allow for complex geometries to be made. A dissimilar steel system consisting of 410 martensitic stainless steel and AWS ER70S-6 mild steel is proposed to make hot stamps, making them more cost-efficient. However, the material interface's mechanical behavior in 410SS-mild steel additively manufactured material systems is not well understood. This …

Significance Of The Neck In Concussive Head Impacts – A Computational Approach, Sakib Ul Islam

Electronic Thesis and Dissertation Repository

With the rising concern of concussions in contact sports, it is believed that cervical muscles could play a vital role in attenuating force to the head. However, the biomechanical effect of cervical muscles on head and brain response is not clearly understood. This study adopted a finite element head and neck model to replicate football impacts under various loading conditions to study the effect of neck muscles on head kinematics. Our results indicate that neck muscles have the highest amount of internal energy absorption in early impact, particularly at the time when peak head kinematics develop. Both deep and superficial …

Investigating Physiological Determinants Of Mental Health In Children With Cerebral Palsy, Daniela A. Testani

Electronic Thesis and Dissertation Repository

Background

Fifty-seven percent of children with cerebral palsy (CP) experience mental health symptoms including symptoms of anxiety and depression. Although CP is non progressive, secondary conditions can have progressive effects on an individuals’ functional abilities. Particularly, untreated mental health symptoms can negatively affect a child’s quality of life. Children with CP also experience fatigue, pain, poor physical activity, and sleep disturbances. The presence of these physiological symptoms, separate and in combination, may impact mental health; however, it has not been systematically examined. Identifying factors that contribute to mental health symptoms may prevent the maintenance of these issues into adulthood.

Objectives …

Test-Retest Of The 5-Minute Psychomotor Vigilance Test, Katharine Dennison

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The purpose of this study was to evaluate the reliability of many variables in the 5-minute Psychomotor Vigilance Test (PVT). Many studies have looked at the validity of a 5-minute PVT, but few so far have looked at reliability. For this study, 13 adult females who worked 12-hr shifts were recruited to complete a two trial day study. The first trial day, the subjects submitted health questionnaire followed by a self-reported sleepiness scale and then a 5-minute PVT. The second trial session the subjects only competed the sleepiness scale followed by the 5-minute PVT. After analyzing the data, it was …

Use Of Compassion Fatigue Education And Guided Imagery To Reduce Compassion Fatigue In The Oncology Nurse, Laura Mahoney

Graduate Theses, Dissertations, and Capstones

Abstract

Background: Oncology nurses are exposed to their patients’ extreme suffering and death. This exposure places them at risk of developing Compassion Fatigue. Compassion Fatigue is often described as trauma that results from caring for those that are suffering. Its sequelae are like post-traumatic stress syndrome, including emotional and physical conditions. Nurses experiencing Compassion Fatigue could jeopardize their health, as well as their patients’ health. Evidence-based interventions may reduce the risk or presence of Compassion Fatigue.

Objectives: The objective of this project was to test an intervention that could prevent or reduce Compassion Fatigue in the oncology nurse. Based on …

Effect Of Obesity On Knee Joint During Walking And Squatting, Simon Vasquez Iii

Theses and Dissertations

This paper analyzes the effect of obesity on the knee joints during squats. This was performed on 2 different subjects by having each squat 30 times at their decided comfortable depth to display some fatigue and effects on the knee joints. Using the VICON NEXUS and AMTI force plates equipment at The University of Texas at Rio Grande Valley Biomechanics Lab, the center of pressure, knee flexion angles, velocity, and ground reaction forces were calculated. The subjects performed the exercises with and without additional weight using a body vest and kettlebell. The ground reaction forces showed a significant increase in …

Evaluation Of Fine And Coarse Graded Asphalt Mixes, Md Mehedi Hasan

Civil Engineering ETDs

During the last 20 years, asphalt pavements were built in New Mexico (NM) and around the country using mostly Superpave coarse graded mixes as opposed to fine graded mixes. This is because coarse mix uses larger aggregates with good interlocking and requires less asphalt binder than a fine mix, while both mixes fulfill the Superpave criteria. Recently, it was observed nationally that the Superpave coarse graded mixes have good field rutting performances but poor cracking performances. It is hypothesized that fine graded mix can help improve pavement cracking performances. The idea is, the fine mixes would have less air voids …

In Vitro Study To Analyze Reverse Torque Values Of Prosthetic Screws With Multiple Loosening/Tightening Preload Cycles, Amira Alhameed

Master's Theses (2009 -)

Purpose: To determine the number of loosening/tightening preload cycles prosthetic retaining screws can withstand before fracture, and to record the reverse torque values on each of the 10 applications of screw tightening and loosening. Materials and methods: The testing assemblies consisted of 30 temporary cylinder/multiunit abutment/internal connection implants, 10 each from Biohorizons, Zimmer Biomet Dental, and Dentsply Sirona Astra; the specimens were inserted into resin blocks. Temporary cylinders were connected to the abutments with new prosthetic screws and torqued to the appropriate preloads. The first tests of repeated tightening/loosening preload cycles were applied using a Digital ® torque gauge instrument …

The Effect Of An On Body Personal Lift Assist Device (Jaipur Belt) On Trunk Muscle Fatiguability During A Repetitive Lifting Task In Manual Material Handlers – A Non-Randomized Single-Group Trial., Betty Thomas

Kasturba Medical College, Mangalore Theses and Dissertations

No abstract provided.

Perspectives Of Indian Elderly Women About Fatigue In Daily Occupations: An Exploratory Study, Nilakshi Subhash Shirodkar

Manipal College of Health Professions, Manipal Theses and Dissertations

Fatigue is one of the most common complaint reported by the elderly. The daily functioning and independence of the elderly may be compromised due to fatigue. It is also studied that fatigue is more prevalent in elderly women than elderly men. Hence, our study aimed to explore the perspectives of Indian elderly women about fatigue in daily occupations. A qualitative study using phenomenological approach was used to explore the experiences of elderly women with fatigue. 12 elderly women were recruited and were interviewed either via telephone or in-person. A semi-structured interview guide was used to elicit information related to fatigue …

Human Fatigue Predictions In Complex Aviation Crew Operational Impact Conditions, Suresh Rangan

Doctoral Dissertations

In this last decade, several regulatory frameworks across the world in all modes of transportation had brought fatigue and its risk management in operations to the forefront. Of all transportation modes air travel has been the safest means of transportation. Still as part of continuous improvement efforts, regulators are insisting the operators to adopt strong fatigue science and its foundational principles to reinforce safety risk assessment and management. Fatigue risk management is a data driven system that finds a realistic balance between safety and productivity in an organization. This work discusses the effects of mathematical modeling of fatigue and its …

Kopos: A Framework To Study And Detect Physical And Cognitive Fatigue Concurrently, Varun Ajay Kanal

Computer Science and Engineering Dissertations

Fatigue is one of the most prevalent phenomena in human beings, and yet its detection is highly subjective and poorly understood. The phenomenon of fatigue has a huge impact on performance, the ability to execute tasks safely and correctly, and the ability to retain or secure a job. Fatigue can be classified into two types: physical and cognitive fatigue. Physical fatigue may occur due to excessive physical exertion, while cognitive fatigue may occur due to excessive mental exertion. Historically, these two types of fatigue have been studied independently. However, in the real world, although these often occur at the same …

Stress Management For Student-Athletes: Stress Levels And Mitigation Strategies For Athletes And Coaches At A Faith-Based University, Caleb Herman

Master of Education Program Theses

Research demonstrates that college is a stressful time of life, especially for student-athletes who are involved in both athletics and academics (Lopes Dos Santos et al., 2020). While research exists that proposes strategies for helping either students or athletes cope with the stress that they face, very little research specifically addresses the needs of student-athletes. The purpose of this study was to determine effective ways in which coaches can mitigate stress for student-athletes at faith-based universities. Through a measurement of the anxiety and depression levels that student-athletes at Dordt University experience, correlations were made between exhaustion levels, a reduced sense …

Behaviour Of Wrinkled Energy Pipes Subjected To Axial Cyclic Induced Fatigue Failure, Habeeb Boluwatife Sobanke

Electronic Theses and Dissertations

The energy industry has since been faced with the issue of development of wrinkle defect on buried pipelines located in vicious environment. Although, there have been different literatures on how to assess the integrity of pipelines with structural defects such as; corrosion, dents, buckles and welds, limited research data or guideline(s) are available on how to assess the severity of small wrinkle defects. Failure to assess the severity of these wrinkle defects, especially in buried pipelines located in the regions prone to geotechnical movement and extreme seasonal temperature variation, may lead to shutdown of the pipeline operations, and as result …

Relationships Among Nursing Presence, Openness, And Fatigue In Acute Care Nurses, Barbara Therese Pudelek

Dissertations

Nursing presence was first identified when Florence Nightingale established a physical nursing presence or "being" and providing compassionate care or "doing" in the military hospitals during the Crimean War (Watson, 1998; Boeck, 2014; Dossey, 2000). Nursing presence has been a central focus in nursing throughout the past several decades (Turpin, 2014) and has been positively linked to the development of nurse-patient relationships. Nursing presence has been hypothesized to transpire when a joint relationship develops between the patient and the nurse. The patient allows the nurse into a relationship in which the nurse recognizes the patient as a unique being and …

Parenting A Child With Autism: Predictors Of Parental Self-Efficacy, Robert Milton Guy

Walden Dissertations and Doctoral Studies

As the rate of children being diagnosed with autism spectrum disorder (ASD) increases, so too does the number of parents learning to cope with their child’s disability and its effects on their own health, well-being, and parental self-efficacy. The purpose of this study was to determine the extent to which subjective social status, parental social supports, and fatigue were factors predicting parental self-efficacy in parents of children diagnosed with ASD residing in the state of Oregon. Bandura’s social cognitive theory was used to frame this study. The sample for this study consisted of 120 parents of children diagnosed with ASD …

Comparison Of The Times To Exhaustion, Physiological, Perceptual, And Neuromusuclar Responses During Constant Heart Rate, Constant Vo2, And Constant Power Exercise, Pasquale Jiovanni Succi

Theses and Dissertations--Kinesiology and Health Promotion

The purposes of this study were to: 1) Determine if there are differences in the sustainability of exercise when anchored at critical heart rate (CHR), the VO₂ associated with CHR (VO₂CHR), or the power output associated with CHR (PCHR); 2) examine the patterns of responses in power output, metabolic (heart rate [HR], VO₂, respiration rate [RR]), neuromuscular (electromyographic [EMG] amplitude [AMP], mean power frequency [MPF], mechanomyographic [MMG] AMP and MPF, perceptual (rating of perceived exertion [RPE]), and muscle oxygenation responses (%SmO₂) during exercise anchored by HR, VO₂, and power output; and …

The Relationship Of Fatigue And Parental Disability In Mothers With Inflammatory Arthritic Conditions In Comparison To Mothers Without Chronic Diagnoses., Chrystina Maria Bonelli, Victoria Priganc, Susan Kasser, Kris Winston

UVM Patrick Leahy Honors College Senior Theses

Research suggests there is limited information surrounding how fatigue and parental disability impact the occupation of mothering. A woman’s dual role of mother and patient is rarely addressed, presenting unique parenting challenges and greater disability. The primary objective of this study was to explore the relationship between fatigue and mothers with inflammatory arthritic conditions comparatively to mothers without chronic conditions. Secondarily, the purpose of the study was to utilize the parental disability index and qualitative questions to examine further the impact of being a mother with an inflammatory rheumatological condition. Seventy-one mothers between the ages of 22-48 participated in the …

Examination Of Sex- And Limb-Specific Fatigue During Unilateral, Isometric Forearm Exercise, Caleb Christian Voskuil

Theses and Dissertations--Kinesiology and Health Promotion

The purpose of this study was to examine the effects of unilateral, isometric handgrip holds to failure for the dominant (Dm) and non-dominant (NDm) limb on ipsilateral ([IPS] exercised side) and contralateral ([CON] non-exercised side) performance fatigability. Twenty individuals participated in this study (Men [n =10]; Women [n = 10; Composite Demographics: Age: 22.2 years; Height: 174.4 cm; Body Mass: 75.0 kg) and completed three visits. Two, 6 s maximal voluntary isometric contractions (MVICs) for the Dm and NDm limb were performed during visit 1, followed by a familiarization of the fatigue test. Visits 2 and 3 included an isometric, …

The Acute Effect Of High Intensity Resistance Training On Subsequent Firefighter Performance, Mark Ryan Mason

Theses and Dissertations--Kinesiology and Health Promotion

High intensity resistance training (HIRT) is commonly performed by structural firefighters to enhance preparedness for occupational demands. Despite the potential for HIRT to induce beneficial adaptations over time, it is important to determine if a single on-duty HIRT session is detrimental to subsequent occupational physical ability due to exercise-induced fatigue. Therefore, the primary purpose of this study was to assess the acute effect of HIRT on occupational physical ability in structural firefighters and to determine the time course of recovery. The secondary purpose was to determine if timed completion of a standardized bout of HIRT was correlated to occupational performance …

Electromyographic And Mechanomyogrpahic Signal Changes With Fatigue In Adults, Rehana Koilpillai

Honors Undergraduate Theses

Surface electromyography (sEMG) and mechanomyography (MMG) are well-studied signals that can reveal information about the physiological behavior of muscles during contraction. The purpose of this study was to quantify, characterize, and analyze the electrical and mechanical muscle responses to submaximal, isometric contractions in the rectus femoris in adults. Previous studies have investigated the use of EMG to monitor muscle fatigue. However, more information appears to be needed about the use of MMG to measure muscle fatigue during submaximal isometric contraction in the rectus femoris. In this study, the utility of MMG as a measure of muscle fatigue or muscle state …

Long-Term Disability Following A Hamstring Injury, Savannah Mclain

Electronic Theses and Dissertations

PURPOSE: Injuries to the hamstring complex are one of the most commonly seen lower extremity injuries in athletic populations. It is currently unknown how psychological or sociological factors affect an athlete after the recovery process has ended and if these factors play a role in re-injury rates relating to the hamstring. It is also unknown if athlete confidence level changes while in a fatigued state after an athlete returns to play from a hamstring injury. METHODS: Twenty-six physically active adults with and without a previous hamstring injury were recruited for this study. Participants completed a Qualtrics survey that …

The Effect Of Microstructural Defect Evolution During Elastic Fatigue Loading On Subsequent Mechanical Properties, Joseph Indeck

Dissertations

Evolution of mechanical properties due to fatigue loading is often overlooked in the design process. Material properties in the as-received condition from a vendor are characterized and then these properties become the basis of design considerations. The effect of expected fatigue loading during operation and its potential to degrade mechanical performance is frequently accounted for with appropriate safety factors. Most notably, the aerospace industry does not have the luxury of large safety factors due to the detrimental effect of weight on cost and performance. Therefore, it becomes necessary to quantify not only the change in mechanical properties as a function …

Mechanisms And Therapeutic Interventions For Breast Cancer-Induced Fatigue And Mitochondrial Dysfunction, David Andrew Stanton

Graduate Theses, Dissertations, and Problem Reports

According to the latest statistics from the National Cancer Institute (NCI), about 1 in 8 U.S. women (~13%) will develop invasive breast cancer over the course of their lifetime. This translates to an estimated 268,600 new cases of breast cancer for the year 2019, and these diagnoses will collectively make up 15% of all new cancer cases across all cancer types. The majority of these women will experience the often-debilitating symptom of breast cancer-induced fatigue. these patients often have difficulty performing normal activities of daily living, have decreased tolerance to traditional tumor-directed therapies, and have higher rates of cancer recurrence. …