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Tung, David C.Welding Metallurgy of Nickel-Based Superalloys for Power Plant Construction
Doctor of Philosophy, The Ohio State University, 2015, Welding Engineering
Abstract Increasing the steam temperature and pressure in coal-fired power plants is a perpetual goal driven by the pursuit of increasing thermal cycle efficiency and reducing fuel consumption and emissions. The next target steam operating conditions, which are 760°C (1400°F) and 35 MPa (5000 psi) are known as Advanced Ultra Supercritical (AUSC), and can reduce CO2 emissions up to 13% but this cannot be achieved with traditional power plant construction materials. The use of precipitation-strengthened Nickel-based alloys (superalloys) is required for components which will experience the highest operating temperatures. The leading candidate superalloys for power plant construction are alloys 740H, 282, and 617. Superalloys have excellent elevated temperature properties due to careful microstructural design which is achieved through very specific heat treatments, often requiring solution annealing or homogenization at temperatures of 1100 °C or higher. A series of postweld heat treatments was investigated and it was found that homogenization steps before aging had no noticeable effect on weld metal microhardness, however; there were clear improvements in weld metal homogeneity. The full abstract can be viewed in the document itself.

Committee:

John Lippold (Advisor); Boian Alexandrov (Committee Member); Antonio Ramirez (Committee Member)

Subjects:

Materials Science; Metallurgy

Keywords:

Welding Metallurgy; Stress Relaxation Cracking; Stress Relief Cracking; 740; 282; 617; AUSC; Advanced Ultra Supercritical; PWHT; Stress Relaxation Testing; Stress Relief Testing; Compact Tension Samples; Residual Stress; Pre-Compression; Superalloy;

Franceschelli, Anthony AlbertSex Differences in the Rapid and the Sustained Antidepressant-like Effects of Ketamine in Stress-naive and “Depressed” Mice Exposed to Chronic Mild Stress
Master of Science (M.S.), University of Dayton, 2015, Biology
During the past decade, one of the most striking discoveries in the treatment of major depression was the clinical finding that a single infusion of a sub-anesthetic dose of the N-methyl-D-aspartate receptor antagonist ketamine produces a rapid (i.e. within a few hours) and long-lasting (i.e. up to two weeks) antidepressant effect in both treatment-resistant depressed patients and in animal models of depression. Notably, converging clinical and preclinical evidence support that responsiveness to antidepressant drugs is sex-differentiated. Strikingly, research regarding the antidepressant-like effects of ketamine has focused almost exclusively on the male sex. Herein we report that female C57BL/6J stress-naive mice are more sensitive to the rapid and the sustained antidepressant-like effects of ketamine in the forced swim test (FST). In particular, female mice responded to lower doses of ketamine (i.e. 3 mg/kg at 30 min and 5 mg/kg at 24h post-injection), doses that were not effective in their male counterparts. Moreover, tissue levels of the excitatory amino acids glutamate and aspartate, as well as serotonergic activity, were affected in a sex-dependent manner in the prefrontal cortex and the hippocampus, at the same time-points. Most importantly, a single injection of ketamine (10 mg/kg) induced sex-dependent behavioral effects in mice subjected to the chronic mild stress (CMS) model of depression. Intriguingly, female mice were more reactive to the earlier effects of ketamine, as assessed in the open field and the FST (at 30 min and 24 h post-treatment, respectively) but the antidepressant potential of the drug proved to be longer-lasting in males, as assessed in the splash test and the FST (days 5 and 7 post-treatment, respectively). Taken together, present data revealed that ketamine treatment induces sex-dependent rapid and sustained neurochemical and behavioral antidepressant-like effects in stress-naive and CMS-exposed C57BL/6J mice.

Committee:

Pothitos Pitychoutis, Dr. (Advisor); Carissa Krane, Dr. (Committee Member); Amit Singh, Dr. (Committee Member)

Subjects:

Behavioral Sciences; Biochemistry; Biology; Biomedical Research; Gender Studies; Neurobiology; Neurosciences; Pharmacology

Keywords:

Ketamine; sex; gender; sex differences; chronic mild stress; mice; female; nmda; antidepressant; stress; chronic stress; chronic unpredictable stress; nmdar; gender differences; depression; major depression; major depressive disorder;

Kotian, KunalDetection of in-plane stress waves with Polyvinylidene Fluoride (PVDF) sensors
Master of Science, The Ohio State University, 2013, Mechanical Engineering

Polyvinylidene Fluoride (PVDF), a piezoelectric polymer, is an excellent stress sensor. The objective of this research is to investigate the application of the PVDF sensors for detection of in-plane stress waves in 31 and 32 modes. This was achieved by focusing on aspects of PVDF sensing related to determination of impact force, detection of stress wave propagation, and the stress averaging effect of PVDF sensors.

An experimental method was developed for calculating a proportionality constant between a PVDF sensor's voltage and the impact force, on a solid bar and a hollow beam. This was used to demonstrate that impact force on a structure can be determined using PVDF sensors. Finite element models were also created using the software LS-DYNA to simulate the impact tests. The speed of sound for longitudinal wave propagation in a slender rod was determined experimentally, using two PVDF sensors. The results demonstrate that PVDF sensors can detect high speed stress wave propagation in a structure. Finally, the stress averaging effect of the PVDF sensor was analyzed to investigate its influence on the generated voltage during stress wave detection. Equations modeling the stress averaging effect were derived for periodic applied stress waves and impact-induced stress waves. Numerical simulations were conducted to study the influence of sensor length, applied wave frequency, and structure's material on the stress averaged PVDF response.

Committee:

Marcelo Dapino, PhD (Advisor); Daniel Mendelsohn, PhD (Committee Member)

Subjects:

Mechanical Engineering

Keywords:

PVDF sensor; in-plane stress; impact testing; stress wave detection; stress averaging; LS-DYNA impact simulation

Backus, LisaSanctification of Work: A Potential Moderator of the Relationship between Work Stress and Health
Doctor of Philosophy (Ph.D.), Bowling Green State University, 2013, Psychology/Clinical
Work stress has long been a topic of interest in both the academic world and popular culture. Work stress has been linked to a number of negative outcomes, including both mental and physical health. Religiosity, on the other hand, has been shown to increase well being. Research has shown that the sanctification of work may be linked to higher levels of positive outcomes such as job satisfaction. However, links between work stress in human services work and health outcomes, and how the sanctification of work may affect this relationship, have not been directly examined. The purpose of the current study was to address this gap in the research. This study examined links between work stress, health outcomes, and the sanctification of work. 104 employees living in either the Northeast or the Midwest and working in the human services field completed a series of measures designed to address these constructs. It was hypothesized that work stress would be linked to poor outcomes, sanctification would be linked to positive outcomes, and that sanctification would buffer the relationship between work stress and poor outcomes. Results were mixed in regards to confirming current hypotheses. With some exceptions, main analyses revealed that work stress was linked to poorer health outcomes and sanctification was linked to positive outcomes. Moderation analyses provided mixed support regarding the role of sanctification as a moderator. These findings are discussed along with implications, limitations, and future directions.

Committee:

Steve Jex, PhD (Committee Chair); Kenneth Pargament, PhD (Committee Member); Robert Carels, PhD (Committee Member); Gregory Rich, PhD (Committee Member)

Subjects:

Clinical Psychology; Health; Mental Health; Organizational Behavior; Psychology; Religion; Spirituality

Keywords:

Work Stress; Job Stress; Stress; Human Services; Social Services; Sanctification; Religion; Spirituality; Health; Mental Health; Physical Health; Adverse Outcomes

Cheung, Michael BrianImmune System mModulation in Victims of Intimate Partner Violence
Master of Science, University of Akron, 2009, Biology
The immune system is responsible for protecting the body from disease by identifying by destroying pathogenic microorganisms, materials and even dangerous self-cells. This protection is carried out by specialized cells which are found in the bone marrow, circulating blood, thymus, lymph nodes, spleen, as well as other lymphatic tissues. These cells each carry out specific functions and convey different types of protection. Modulation of the balance of either the number or functionality of these immune cells can lead to immune deficiency, susceptibility to disease, or autoimmune disorders such as chronic inflammation. A number of studies have shown that the immune system can be affected by both physical and psychological stresses, such as depression and post-traumatic stress disorder (PTSD). In the present study we examined immune status in women victims of intimate partner violence (IPV). Immune system parameters measured included both immune cell counts as well as functionality of the cells. The results indicated that victims of IPV who suffered from depression and PTSD showed significantly higher baseline activity of natural killer (NK) cells and decreased change in NK cell activity when stimulated with heat shock protein 60 (HSP60). This drop in reactivity to a typical cellular stress signal could put PTSD positive IPV victims at risk for a number of diseases, including cancer development and viral infection. Also, an increased basal activity of NK cells could indicate an autoimmune pathology. These results may lead to a better understanding of the health issues associated with IPV, PTSD, and depression, and will hopefully assist in the development of better and more complete therapies.

Committee:

James Holda, PhD (Advisor)

Subjects:

Biology; Health; Immunology; Psychobiology; Womens Studies

Keywords:

IPV; intimate partner violence; PTSD; Post-Traumatic Stress Disorder; Posttraumatic Stress; Immune System; Natural Killer Cells; Psychoneuroimmunology; Immune System Modulation; Stress and the Immune System

Saul, Alison NicolePsycho-physiological stress and its effects on ultraviolet light induced inflammation, DNA damage, and skin carcinogenesis
Doctor of Philosophy, The Ohio State University, 2007, Integrated Biomedical Science
Skin cancer is the most common type of cancer in the United States and it is primarily caused by the exposure to ultraviolet-B radiation. Non-melanoma skin cancers, such as basal cell carcinoma and squamous cell carcinoma comprise the majority of skin cancer cases. Ultraviolet-B radiation induces a host of changes in the skin, the primary target of UVB, including inflammation, DNA damage, and eventually skin carcinogenesis. UVB radiation can also induce immunosuppression. This immunosuppression makes it less likely that the immune system will be able to respond efficiently to immunogenic tumors such as squamous cell carcinomas. Therefore, we would predict that factors that can affect cell-mediated immunity would also have a high likelihood of affecting SCC tumor development as well. Psycho-physiological stress is powerful modulator of immune system function as well. While short-term (acute) stress enhances cell-mediated immunity long-term (chronic) stress suppresses cell-mediated immunity. We have used these stressors in combination with UVB radiation to understand the effects of psychological stress on UVB induced inflammation, DNA damage, and ultimately SCC skin carcinogenesis. Using techniques such as immunohistochemistry, real-time PCR, flow cytometry, and ELISA, we found that acute stress reduced DNA damage, enhanced gene expression of Th1 cytokines and chemokines in the skin, and enhanced leukocyte traffic, primarily T cell, into the skin and sites of tumor formation. As a result of this, acute stress reduced SCC tumor development. In contrast to these results, we found that chronic stress increased DNA damage, decreased the gene expression of Th1 cytokines and chemokines in the skin, and decreased T cell infiltration into the skin and sites of tumor formation. As a result of this, chronic stress increased SCC tumor development. Finally, we examined anxiety levels in our mice and because we considered high anxiety as a type of innate chronic stress, we predicted that anxiety would produce the same types of effects in response to UVB as chronic stress. This was, in fact, the case as the high anxiety mice had reduced levels of Th1 cytokines and chemokines and also reduced T cell infiltration which caused increased SCC tumor development.

Committee:

Tatiana Oberyszyn (Advisor)

Keywords:

psychological stress; chronic stress; acute stress; skin cancer; UVB radiation; Th1 cytokines; T cells

Roush, Laura E.Impact of Life Event and Cancer-related Traumatic Stress on the Degree of Global Perceived Stress in Women with Breast Cancer
PhD, University of Cincinnati, 2008, Arts and Sciences : Psychology
As the second leading cause of cancer death for women in the United States (American Cancer Society, 2007), a breast cancer diagnosis strongly implies a threat on a woman’s life. A number of studies demonstrate the stressful nature of a breast cancer diagnosis and subsequent treatment for the disease (e.g., Baider & Kaplan De-Nour, 1997; Golden-Kreutz et al., 2005). Life event, global perceived, and traumatic stress represent three of the most frequent lines of stress research. Little research has been done to compare the three types of stress in the same sample, making it difficult to separate the contribution of each type. The few studies that have been done with all three types find that each is uniquely related to psychological distress or physical and psychological quality of life (Golden-Kreutz et al., 2005). Although research finds that life event stress is related to initial traumatic stress levels (Butler, Koopman, Classen, & Spiegel, 1999), no known studies have examined the impact of cancer-related traumatic stress and life event stress on these women’s sense of being globally overwhelmed in their lives. This longitudinal study hypothesized that higher levels of stress specifically related to the cancer diagnosis, and/or higher levels of stress related to life events in the year leading up to diagnosis, would predict the degree that women felt overwhelmed by life in general. Data from 72 women with early stage (0/I/II) breast cancer were followed from shortly after diagnosis to one year after chemotherapy treatment concluded, or 24 months after the start of hormonal therapy. Results show that cancer-specific stress significantly predicted global stress levels around the time of diagnosis. However, cancer-specific stress did not explain variance in later levels of perceived stress beyond that of initial perceived stress levels. In contrast, life event stress did not contribute significantly to the prediction of initial stress levels, but did explain a significant amount of variance in long-term perceived stress levels. Thus, life event stress and perceived stress measures may be the best screening tools for long-term risk for heightened global stress, while cancer-related stress may provide unique predictive power closer to diagnosis.

Committee:

Christine Hovanitz, Ph.D. (Committee Chair); Laura Nabors, Ph.D. (Committee Member); Robert Stutz, Ph.D. (Committee Member)

Subjects:

Psychology

Keywords:

breast cancer; perceived stress; traumatic stress; life event stress

Lorah, Ashley MEffects of Aerobic and Mental Exercises on College Students' Stress
Bachelor of Science, Ashland University, 2016, Sport Sciences
The goal of this study was to determine whether aerobic and mental exercise would have a statistically significant effect on reducing stress in college-aged non-athlete students. The data were collected from 25 undergraduate students at a private university in Ohio. The results were analyzed to determine if significant differences existed between the aerobic, mental and control groups. The study found that there were no statistically significant differences among the three groups.

Committee:

Glen Fincher, II, Ph.D. (Advisor); Beth Patton, Ph.D. (Committee Member)

Subjects:

Kinesiology

Keywords:

stress; stress reduction; exercise; physical activity; aerobic exercise; mental exercise; college students; Perceived Stress Questionnaire

Julian, Michael RobertMaterial characterization of viscoelastic polymeric molding compounds
Master of Science, The Ohio State University, 1994, Engineering Mechanics

Committee:

Vernal Kenner (Advisor)

Keywords:

STRAIN-RATE; Strains; Master Curve; STRESS-STRAIN; Log E versus Log; Stress versus Strain for Strain-Rate; STRESS-RELAXATION

Darvesh, Altaf SultanStudies on the 3,4-methylenedioxymethamphetamine (MDMA)-induced dysregulation of energy metabolism and its neurochemical consequences
PhD, University of Cincinnati, 2005, Pharmacy : Pharmaceutical Sciences
3,4-Methylenedioxymethamphetamine (MDMA), an analog of the amphetamine class, is a psychostimulant and a popular drug of abuse. MDMA is considered to be selectively neurotoxic to serotonergic nerve terminals in different brain regions, however the exact mechanisms through which MDMA produces serotonin (5-HT) neurotoxicity remain unknown. Oxidative stress has been reported to play an important role in mediating this process. In addition to the potential role of oxidative stress in MDMA neurotoxicity, there is evidence that bioenergetic stress may play an important role in the toxicity produced by amphetamine analogs. The overall hypothesis, which provides the basis for the current proposal is that MDMA produces dysregulation of brain energy metabolism and this plays an important role in MDMA-induced neurotoxicity.The effect of MDMA on brain energy metabolism was investigated by examining the effect of MDMA on brain glycogen. MDMA produced a time and dose-dependent decrease in brain glycogen. Maintenance of rats at a cool ambient temperature of 17 0C or pretreatment with 5-HT2 antagonists, significantly attenuated the MDMA-induced hyperthermia and glycogenolysis. However, MDMA-induced hyperthermia, as well as glycogenolysis, was found to be neither sufficient nor necessary for the MDMA-induced long-term 5-HT depletion.Administration of substrates of energy metabolism, e.g., nicotinamide, ubiquinone, attenuated the MDMA-induced long-term 5-HT depletion. Nicotinamide also attenuated the long-term DA and 5-HT depletion produced by coperfusion of MDMA and the mitochondrial inhibitor malonate. A neurotoxic regimen of MDMA produced a significant depletion of ATP in the striatum and hippocampus. Dysregulation of energy metabolism and energy depletion results in increased intracellular Ca2+ levels in the mitochondria, which results in activation of nitric oxide synthase (NOS) and generation of nitric oxide (NO). A neurotoxic regimen of MDMA produced an increase in NO in the striatum. The MDMA and malonate-induced long-term DA and 5-HT depletion were attenuated by administration of NOS inhibitors, as well as a peroxynitrite decomposition catalyst. The neuronal NOS inhibitor S-methyl-L-thiocitrulline (S-MTC) attenuated the MDMA-induced long-term 5-HT depletion without attenuating the MDMA-induced hyperthermia.These results support the conclusion that MDMA produces dysregulation of energy metabolism and this bioenergetic stress contributes to MDMA-induced neurotoxicity.

Committee:

Dr. Gary Gudelsky (Advisor)

Subjects:

Health Sciences, Pharmacy

Keywords:

3,4-Methylenedioxymethamphetamine; Neurotoxicity; Serotonin; Oxidative stress; Bioenergetic stress; Energy metabolism

Rochette, Lynne M.Gender Differences in Cardiovascular Reactivity to Stress between Friends, Acquaintances, and Strangers
Doctor of Philosophy (PhD), Ohio University, 2010, Psychology (Arts and Sciences)
The purpose of this study was to assess the association between gender and closeness of the support provider on cardiovascular reactivity to acute stress. Volunteers were randomly assigned to undergo a laboratory visit with a close friend, acquaintance, or stranger. During the testing session, systolic blood pressure, diastolic blood pressure, mean arterial blood pressure (MAP) and impedance cardiography assessments of heart rate (HR), stroke volume, cardiac output, pre-ejection period, and total peripheral resistance were assessed during a fixed order protocol: baseline, adaptation baseline, math task, intermediate baseline, speech preparation period, speech task, and recovery. The support provider was present from adaptation baseline throughout the remainder of the protocol. During speech preparation stress, support from acquaintances produced the lowest HR reactivity for male individuals and support from strangers produced the lowest HR reactivity for female individuals. Also, individuals receiving support from a female support provider displayed less MAP reactivity than individuals receiving support from a male support provider. No significant effects for support provider type or gender were found during the math or speech stressor. Unexpectedly, assigned support provider type group differences were found for resting cardiovascular function at baseline, even though the support provider was not physically present during the cardiovascular assessments. Resting MAP was higher for the friend condition compared to the stranger condition, but no differences were observed with the acquaintance condition. Also, an interaction of support provider type by participant gender was found for resting HR, which illustrated that HR was lowest among males who were assigned to receive support from an acquaintance, but highest among females who were assigned to receive acquaintance support. Although these differences in resting cardiovascular function may be merely coincidence, it is plausible that asking participants to think about quality elements of their relationship with the support provider mentally activated thoughts of the provider, which influenced resting cardiovascular function. Altogether, the limited support of study hypotheses appear to indicate the type of person providing support is not an important element of the social support interaction when actual support provision is standardized among three types of relationships (close friends, acquaintances, strangers).

Committee:

Stephen M. Patterson, PhD (Advisor); Christopher France, PhD (Committee Member); Bruce Carlson, PhD (Committee Member); Kathi Heffner, PhD (Committee Member); Robert Shelly, PhD (Committee Member)

Subjects:

Health; Physiological Psychology; Social Psychology

Keywords:

Social Support; Friendship; Psychological Stress; Health Psychology; Relationships; Cardiovascular Reactivity; Stress-Reactivity; Coping; Gender; Closeness

Petersen, Trevor JEvaluation of a Stress Management Program for Newly Matriculated First-Generation College Students: A Randomized Controlled Trial
Doctor of Philosophy (PhD), Ohio University, 2013, Clinical Psychology (Arts and Sciences)
National surveys indicate that approximately 15.9 percent of full-time students attending 4-year universities in the U.S. for the first time come from families where neither of their parents attended college (Pryor et al. 2006). These "first-generation college students" have been deemed an at-risk group based on evidence that they experience extensive stressors, both those related to adjusting to being a college student generally as well as unique disadvantages and heightened stressors related to factors associated with their first-generation status (Choy, 2001; Pryor et al., 2006; Thayer, 2000). Although previous studies have examined the outcomes of stress management programs for college students, these studies have methodological limitations and no known study has examined the areas of impact of such an intervention for first-generation college students specifically. Accordingly, the present project examined important adjustment outcomes of a stress management program designed to help first-generation freshman effectively cope with the demands of college life. Using a RCT design, 56 incoming first-generation college students were randomly assigned to either a control or an intervention group. Participants in the intervention group participated in a weekly 7-session mind/body stress management and support group. All participants completed a pre- and post-intervention assessment that included measures of distress/impaired functioning, social support, health promoting behaviors, adaptive coping, and academic performance. Using MANCOVA, controlling for pre-intervention differences between groups, there was a significant difference at post-intervention between the intervention and control group on the combined dependent variables. Specifically, the intervention group reported significantly lower distress and impaired functioning, significantly greater social support, marginally greater health promoting behaviors, and no significant difference in perceived stress and adaptive coping. Independent samples t-tests revealed no difference between intervention participants and controls in GPA at either post-intervention or 16 week follow-up. Participant satisfaction with the intervention was high. These results indicate that university personnel may improve important areas of short-term adjustment to college in first-generation freshman by providing them with stress management programs to complement extant support services offered them.

Committee:

Bernadette Heckman, Ph.D. (Committee Chair); Garske John, Ph.D. (Committee Member); Anderson Timothy , Ph.D. (Committee Member); Marcks Brook, Ph.D. (Committee Member); Meyer Hans, Ph.D. (Committee Member)

Subjects:

Counseling Education; Counseling Psychology; Psychology

Keywords:

First Generation College Students; Freshman College Students; Adjustment to College; Stress; Stress Management; Support Group; Randomized Controlled Trial; RCT

Panganiban, April RoseTask load and evaluative stress in a multiple UAV control simulation: The protective effect of executive functioning ability
PhD, University of Cincinnati, Arts and Sciences: Psychology
Abstract The use of unmanned aerial vehicles (UAVs) is increasing worldwide and in the U.S. will include federal and commercial sectors as well as the military. Although a demand for suitable operators is growing, surprisingly, there exist no precise criteria for operator selection of remote piloted aircraft. Due to the transition from operator control of a single UAV to multiple UAVs, factors related to attentional control will be important for pilot selection. The current study examined the potential benefit high executive functioning (EF) played in UAV simulation where high task load and evaluative stress were present. Basic cognitive control elements of EF (i.e., inhibition, switching and the updating and monitoring of working memory) were assessed. Participants (N = 92) were recruited into either an evaluative stress (negative feedback) or control group. Two practice trials were performed prior to the two experimental trials; task load was counterbalanced across participants. State measures were taken at baseline and following each trial using the Positive and Negative Affect Schedule (PANAS) and Dundee Stress State Questionnaire (DSSQ).Additionally, workload was assessed after each trial using the NASA-Task Load Index (NASA-TLX). The results of the study showed that UAV performance was more sensitive to task related stress compared to evaluative stress. All UAV performance measures showed a decline with high task load except search accuracy. Evaluative stress interacted with task load revealing that individuals receiving negative feedback in the high task load condition did not increase waypoint usage, a compensatory behavior. Evaluative stress effectively increased reported stress seen as increases in distress, negative affect and frustration, measured by the NASA-TLX. The manipulations of stress caused differential responses across the various state and workload measures. Surprisingly performance on the EF tasks was related more strongly to subjective stress than to performance. Specifically, high inhibitory ability, as measured by the Stop-Signal task, seemed to play some part in protecting operators from experiencing negative results of stress such as worry, distress, threat appraisal and feelings of situational uncontrollability. Contrastingly, the Letter Memory task (Updating) showed a positive relationship with these same subjective stress factors. As letter memory scores improve more stress experiences are reported. Though this finding is surprising, it is interpreted as a sign of resource availability for processing one’s own stress response. The findings presented are helpful in understanding how the stressors intrinsic to UAV operation impact both subjective stress and performance. Although current findings cannot be generalized to all UAVs, they reveal that caution must be exercised in the implementation of multi-UAV control. Additionally, these findings highlight the benefit of using a metric such as the DSSQ to understand the various forms of operator stress, both task load and evaluative stress. These findings suggest the DSSQ may be useful in understanding how changes in task load, in addition to evaluative stress responses, may arise as UAV job design changes. Lastly, executive functioning, specifically inhibitory ability, may be a key operator trait necessary to preserve mental well-being and protect against stress, although replication of the present findings is required.

Committee:

Gerald Matthews, Ph.D. (Committee Chair); Chung-Yiu Chiu, Ph.D. (Committee Member); Michael Richardson, Ph.D. (Committee Member)

Subjects:

Experiments

Keywords:

multi-UAV;executive functioning;task load;evaluative stress;subjective stress;workload

Strader, Katherine CPhase Transformation Behavior and Stress Relief Cracking Susceptibility in Creep Resistant Steels
Master of Science, The Ohio State University, 2014, Welding Engineering
Cracking has been reported in newly constructed water wall panels of fossil power plants during startup testing. Both high hardness (exceeding 350 HV) and high levels of welding residual stress have been reported in welds of waterwall panels made of T23 and T24 steels. Stress-relief cracking (SRC) is being considered as a possible failure mechanism during high temperature exposure such as PWHT. High temperature exposure of non PWHT-ed welds of Grade T23 and T24 steels leads to hardening in the weld and coarse-grained heat-affected zone (CGHAZ). It has been suggested that such a hardening mechanism can lead to stress-relief cracking (SRC). One of the objectives in this study was to investigate the phase transformation behavior and develop continuous cooling transformation (CCT) diagrams in the CGHAZ of Grade T12, T22, T23, and T24 steels. The GleebleTM thermo-mechanical simulator and a dilatometer were utilized in this study. The CGHAZ microstructure in Grade T23 and T24 steels was a mixture of bainite and martensite with hardness higher than 340 HV in the studied range of t8/5 cooling time from 2 to 50 seconds. The CGHAZ microstructure in Grade T22 gradually changed from a mixture of martensite and bainite to predominantly bainitic with allotriomorphic ferrite. This corresponded to a moderate reduction in hardness from 340 to 300 HV. In Grade T12 steel, the microstructure of the CGHAZ gradually changed from predominantly martensitic with hardness of 340 HV to bainitic and a mixture of bainite with idiomorphic and allotriomorphic ferrite with hardness lower than 230 HV. The other objective of this study was to evaluate the susceptibility to SRC in the CGHAZ of T24 steel and in 3-pass welds of Grade T12, T22, T23, and T24 steel tubes. A GleebleTM-based strain-age cracking test developed at The Ohio State University was modified to better replicate the conditions of PWHT in highly restrained welds and quantify the stress-relief cracking susceptibility in creep resistant steels. In addition to reduction in area and time to failure, the modified test allowed quantification of the stress and strain that cause failure during SRC testing. The SRC testing of the simulated CGHAZ in Grade T24 HC steel revealed ductile failure for samples tested at 600°C and SRC failure mechanism for samples tested at 650°C and higher temperatures. The SRC susceptibility in the tested welds was evaluated based on the maximum PWHT temperature sustained without failure, on the time-to-failure, and on the stress, elongation, and reduction in area at failure. Overall, the welds in Grade T24 and T23 steel had similar resistance to SRC that was higher than in the T22 welds. In terms of time-to-failure and strain at failure, the T12 welds performed better than or equal to the T23 and T24 welds, but failed at significantly lower stress. It was concluded that highly restrained welds in Grade T22, T23, and T24 steels that are loaded with high residual stresses may be susceptible to SRC during PWHT

Committee:

Boian Alexandrov (Advisor); John Lippold (Committee Member)

Subjects:

Materials Science; Metallurgy

Keywords:

stress-relief cracking; stress relief cracking; SRC; creep resistant steel; welds; gas tungsten arc welding; GTAW; reheat cracking; phase transformation; CCT; continuous cooling transformation; fossil power plants; T23; T24; T12; T22; CGHAZ; Gleeble

Scott, Karen A.Alterations in adult behavior as a result of early life manipulations
PhD, University of Cincinnati, 2012, Medicine: Neuroscience/Medical Science Scholars Interdisciplinary

Approximately 20% of people experience at least one depressive episode during their lifetime. Furthermore, a majority of these individuals do not experience full remission of symptoms following current treatment protocols. Drug development has been slow, as the etiology of mood disorders is multifactorial and poorly understood; individual susceptibility is influenced by complex gene-environment interactions. Stress is often reported to precede or exacerbate depressive illness, and is therefore used to model depressive-like symptomatology in laboratory animals. While existing paradigms have been useful, few take into account the cumulative effects of genetics and/or experiences that underlie stress-sensitivity. Naturalistic paradigms that utilize multiple risk factors may better model the development of affective disorders.

These studies examined the effects of prenatal stress on the hypothalamic-pituitary-adrenal (HPA) axis, central serotonergic markers and social status of male rats. As adults, prenatal stress was not associated with altered basal corticosterone (CORT) or CORT response to acute restraint. However, fewer serotonergic neurons were observed within specific subregions of the dorsal raphé nucleus (DRN) of prenatally stressed males. The number of c-Fos immunoreactive serotonergic neurons did not differ in response to acute restraint, suggesting similar levels of activation, and therefore similar CORT response. However, the overall reduction in the number of serotonergic neurons suggests that the potential for differential activation exists. We hypothesized that a different type of challenge in adulthood, like chronic stress, may reveal differences in serotonergic and HPA activity.

As adults, males were housed in the visible burrow system (VBS), a unique housing system designed to reflect the natural environment of rats. The VBS utilizes social stress, which is ethologically relevant to rats and has clear translational value to humans. Chronic social stress, in particular, is associated with the development of mood disorders, and the phenotype of socially subordinate male rats shares many similarities with human depressive symptomatology.

These studies were performed to determine if prenatal stress, a putative risk factor, would increase the likelihood of social subordination. We hypothesized that adult prenatally stressed males would be more susceptible to subordination, and that the combination of prenatal and subordination stress would augment depressive-like symptoms observed in subordinate males. As adults, 2 males, (1 prenatally stressed and 1 non-prenatally stressed male) were housed with 4 females in each VBS. Consistent with our prediction, prenatal stress biased social status; these males became subordinate in 75% of burrows. However, there was no exacerbation of subordinate phenotype in these males; rather, they appeared better adapted to subordinate status. They lost less weight, engaged in fewer agonistic interactions and had fewer wounds than subordinate males in prior studies. Prenatally stressed subordinates also had lower basal CORT than non-prenatally stressed subordinates at the end of VBS housing.

These findings are consistent with the stress match/mismatch hypothesis; adverse prenatal environment may prepare offspring for adversity in adulthood. The mechanisms underlying this effect are unclear, but the observed reduction of serotonergic neurons in the DRN suggests serotonin-mediated alterations in coping strategy. Future studies should address this possibility.

Committee:

Randall Sakai, Ph.D. (Committee Chair); James Eliassen, Ph.D. (Committee Member); James Herman, Ph.D. (Committee Member); Silvana Obici, M.D. (Committee Member); Neil Richtand, M.D. (Committee Member); Stephen Woods, Ph.D. (Committee Member)

Subjects:

Neurology

Keywords:

prenatal stress;HPA axis;serotonin;social stress;mood disorders;corticosterone;

Ross, Genesis R.Teacher Stress, Burnout and NCLB: The U.S. Educational Ecosystem and the Adaptation of Teachers
Master of Science, Miami University, 2010, Family and Child Studies
Teacher stress and burnout (TSB) studies have revealed that TBS has become progressively worse. Researchers have offered explanations as to why TSB has persisted and provided suggestions to manage and cope with TBS. Seemingly, even with the magnitude of attention dedicated to TSB; the prevalence is growing faster than solutions work. In response, this study took a holistic approach that included TSB within the context of influences (e.g., federal policy, individual districts and schools). This study is guided by Ecological Theory and builds on existing explanations and prevailing suggestions for coping with and managing TBS. Finally, this study is timely because of its specific exploration of TSB within the context of No Child Left Behind (NCLB). In this study, regular and special education teachers were interviewed regarding their observations and experiences with TSB. These interviews were analyzed for themes related to Ecological Theory and the Ecosystem of Education.

Committee:

Elisa Radina, PhD (Advisor); Paula Saine, PhD (Committee Member); Joseph Alfred, PhD (Committee Member)

Subjects:

Education; Educational Evaluation; Educational Psychology; Educational Sociology; Educational Theory; Elementary Education; Higher Education; Law; School Administration; Social Research; Social Structure; Social Work; Sociology; Teacher Education; Teaching

Keywords:

Teacher; Teacher Stress; Burnout; NCLB; U.S. Education; Educational Ecosystem; Adaptation of Teachers; Teacher Adaptation; Teacher Stress and Burnout; TSB

Musolin, Kristin M.Evaluating the Effects of Heat Stress on the Cardiovascular System and Psychophysical Response of Firefighters
MS, University of Cincinnati, 2011, Medicine: Occupational Medicine
Limited studies have documented the cardiovascular strain of firefighting. Cardiovascular disease causes nearly 50% of on-duty deaths among U.S. firefighters each year. The study examined the effects of live-and non-live fire drills on cardiovascular and psychophysical responses of 12 male firefighters and 1 female firefighter. In this experimental pre- and post-scenario study design, participants performed three standardized tasks while inside a steel building during their regularly scheduled training drill. Fire training sessions involved a set of three tasks including: hose advancement, search and rescue, and backup, each performed for three to four scenarios. Scenarios included first floor fire, second floor fire for which firefighters had to climb a flight of stairs and basement fire for which firefighters had to descend a flight of stairs. Data on vital signs were collected before training and then pre- and post-scenario. Heat stress is an important contributory risk factor for cardiovascular disease in firefighters. During the training, continuous core body temperature (CT) and heart rate (HR) data were collected using a FDA-regulated radio pill and a Polar heart rate belt, respectively. The radio pill and heart rate belt transmitted data to a receiver that was placed in the inside pocket of the firefighter’s turnout coat. Psychophysical data were collected pre- and post-scenarios, which included perceptions of thermal distress, physical exertion, and respiratory distress. Our hypothesis was that there would be a significant increase from pre-scenario to post-scenario values of cardiovascular and psychophysical parameters. Results showed that there was a significant increase in average heart rate (23%) with a p<0.05 for pre-to post-scenario 2 and a p<0.05 for pre- to post-scenario 3. Percent maximum oxygen consumption resulted in maximal heart rates and reductions from pre- to post-scenarios. Pre-scenario mean was: lower limit=58% and upper limit=69% (n=6). Post-scenario 3 mean % max oxygen consumption reduced to: lower limit=17-26% (n=5). Average core body temperature increase throughout the training also proved to be significant with a p<0.05 pre-to post-scenario 2 and p<0.05 pre- to post-scenario 3. Psychophysical parameter results also showed a significant increase as the training progressed; perceived exertion rating (107%) with a p<0.05, and respiratory distress (150%) with a p<0.05, perception of thermal distress (56%) with a p<0.05. This study addressed the firefighter community’s concerns related to the monitoring of the potential health effects such as a cardiovascular event. The firefighters will be able to use this information to improve self-assessment choice, change emergency response relating to safety, and help them understand the importance of protecting themselves against the detrimental effects of heat stress. The end goal is to develop early signs of effects of heat stress that can be used in a real-time remote monitoring system.

Committee:

Amit Bhattacharya, PhD (Committee Chair); Clara Ross, MD (Committee Member); Paul Succop, PhD (Committee Member)

Subjects:

Occupational Safety

Keywords:

heat stress;core body temperature;radio pill;firefighters;CorTemp;effects of heat stress

Telang, AbhishekA Study of the Effects of Mechanical Surface Treatments on Residual Stresses, Microstructure and Stress Corrosion Cracking Behavior of Alloy 600
PhD, University of Cincinnati, 2015, Engineering and Applied Science: Materials Science
Stress corrosion cracking (SCC) of Alloy 600 has been a major problem in commercial light water reactor (LWR) nuclear power plants. Localized corrosion and intergranular SCC (IGSCC) have been observed in Alloy 600 in the high temperature (288-340 °C) pure water environment of LWRs. Additionally, IGSCC of Alloy 600 has been reported even at room temperature under certain conditions in thiosulfate and tetrathionate solutions. In general, SCC can be attributed to the presence of tensile stress, an aggressive environment and a susceptible microstructure. Therefore, SCC mitigation techniques address these factors by modifying the environment, metallurgical processing treatments and alleviating the tensile stresses by mechanical surface treatments/stress relief. This study investigated the application of laser shock peening (LSP) as a technique to mitigate SCC in Alloy 600. LSP induced large compressive residual stresses (-550 MPa) that decreases gradually through depth. The pressure pulse generated during the LSP treatment causes plastic deformation, resulting in high dislocation density, twins and formation of misoriented sub-grains/crystallites that have sizes in the range of 50-300 nm in the near-surface region. Slow strain rate tests (SSRTs) and constant load tests performed in tetrathionate solution at room temperature were used to evaluate the effect of LSP on the SCC behavior. LSP treated samples had a significantly longer time to failure and reduced susceptibility to SCC as compared with untreated sensitized Alloy 600. These improvements were attributed to LSP induced compressive residual stresses, increased yield strength (YS) and hardening caused by near-surface microstructural changes. SSRTs in simulated PWR environment also show similar results with higher YS, tensile strength and strain to failure. Additionally, the gage section shows fewer cracks and smaller crack lengths in the LSP treated samples as compared with the untreated samples. The other approach involved using mechanical surface treatments/cold work followed by annealing to engineer the Alloy 600 microstructure for increased resistance to corrosion and IGSCC. We demonstrated a novel method of surface grain boundary engineering (SGBE) in Alloy 600 using iterative cycles of ultrasonic nanocrystalline surface modification (UNSM) treatment and strain annealing. Three cycles of UNSM and strain annealing at 900-1000 °C were used to modify the microstructure to a depth of 250 µm from the surface. This surface treatment based method increased the fraction of low coincident site lattice (CSL) grain boundaries whilst decreasing the fraction and connectivity of random high angle boundaries (HABs) in the near surface region. Similar results were achieved using thermo-mechanical processing (TMP) with iterative cycles of 10% cold work and strain annealing in Alloy 600. A disrupted random HAB network and large fraction (70%) of CSL boundaries (Σ3-Σ27) reduced the propensity to sensitization. SSRTs in tetrathionate solutions at room temperature show that SGBE and TMP lowered the susceptibility to intergranular SCC. Detailed analysis using EBSD showed cracks arrested at J1 (1-CSL) and J2 (2-CSL) type of triple junctions. The probability of crack arrest, calculated using percolative models, was higher after SGBE and TMP in Alloy 600 and explains the improved IGSCC resistance.

Committee:

Vijay Vasudevan, Ph.D. (Committee Chair); Seetha Ramaiah Mannava, Ph.D. (Committee Member); Dong Qian, Ph.D. (Committee Member); Rodney Roseman, Ph.D. (Committee Member); Vesselin Shanov, Ph.D. (Committee Member)

Subjects:

Materials Science

Keywords:

Stress Corrosion Cracking;Microstructure;Laser Shock Peening;Microstructure;Grain boundary;Residual Stress

Pearce, Emily AnnaThe Stress-Buffering Model of Social Support in Post-Acute Brain Injury Rehabilitation
Psy. D., Antioch University, 2016, Antioch New England: Clinical Psychology
Currently, 3.2-5.3 million Americans (1.1-1.7%) live with long-term disability resulting from acquired brain injury (ABI). Despite two to three million more being treated yearly for milder injuries and released without further services, those with enduring problems often require ongoing rehabilitation and support. The immediate and long-term costs of ABI are substantial, as are the burdens associated with lifelong sequelae. A clear understanding of prognostic indicators—only some of which have been identified—could assist in reducing these costs and burdens. Social support, which has been linked with physical health and function in populations across the world, is one likely indicator. Family stress, which may influence the availability of social support and which has been independently linked to functional outcomes in various populations, is another. Somewhat surprisingly, the relationship of either with functional outcomes in ABI has yet to be firmly established. Framed by the Stress-Buffering Model of social support, this study examined the extent to which family stress predicts physical function following ABI and whether and how social support moderates this relationship. Data for this study was obtained from a national brain injury database (OutcomeInfo). OutcomeInfo houses demographic, injury, medical, service, and administrative information, as well as ratings and scores from the Mayo-Portland Adaptability Inventory—Fourth Edition (MPAI-4). The MPAI-4 is a questionnaire designed for use in post-acute rehabilitation and support programs, intended to allow facilities to track outcomes and changes throughout treatment. Bivariate Pearson and partial correlation were used in this study to gather preliminary information about the Stress-Buffering Model’s applicability within these post-acute services. Bivariate Pearson correlations revealed no significant relationships between family stress or friend support and physical function. Partial correlations revealed no significant relationships when controlling for several personal and contextual variables both individually and concurrently. This study had several limitations, and results should not be generalized at this point. Despite the lack of significant results, this study presents a coherent conceptual framework within which to examine these relationships further and provides a research design upon which future investigators may build.

Committee:

George Tremblay, PhD (Committee Chair); William Slammon, PhD (Committee Member); Nicholas Cioe, PhD (Committee Member)

Subjects:

Clinical Psychology

Keywords:

brain injury; rehabilitation; outcome; family stress; social support; friend support; physical function; Stress-Buffering; Mayo-Portland; MPAI-4

Anzulovic, BorisAnalysis of vibrational stress relieving
Master of Science, The Ohio State University, 1976, Welding Engineering

Committee:

Roy McCauley (Advisor)

Keywords:

VIBRATIONAL STRESS; STRESS RELIEVING; Residual Stresses; RELIEVING; welding

Flinner, Victor J.The analysis and synthesis of stepped shafts using an interactive approach
Master of Science, The Ohio State University, 1982, Mechanical Engineering

The thesis involves two major parts. The first is to develop a procedure for the general interactive analysis of machine shafts. This includes both deflection and stress calculations with consideration of stress concentrations for arbitrary cross sections. The procedure is programmed to use graphics to help the engineer visualize the problem and results as they are obtained. The procedure is based on linear transfer matrix methods using the fundamental equations of motion for the bending of a beam.

The second major effort in the thesis is to develop an automatic design procedure for round, stepped shafts. This procedure takes into account stress concentrations and failure due to yielding and fatigue. The objective of the design is to determine the lightest shaft satisfying all the strength and deflection conditions specified. This is essentially an optimization problem with the analysis program developed in the first part of the thesis being used in the objective function evaluation. Box's Complex method is the optimization procedure incorporated into the synthesis program.

Committee:

Gary Kinzel (Advisor)

Keywords:

SHAFTS; stress concentrations; Shear Stress; Span supports; Fillets

Berdugo, ClaudiaCell Damage Mechanisms and Stress Response in Animal Cell Culture
Doctor of Philosophy, The Ohio State University, 2010, Chemical Engineering

Animal cell culture is a widely used technology for producing recombinant proteins. The ability to make post-translational modifications and secrete the active forms of the protein into the culture medium represents major advantages over other processes. The growing market demand for pharmaceuticals has created a need for increased production capacity; however, achieving productivity gains in both the upstream stage and downstream processes can subject cells to aggressive environments such as those involving hydrodynamic stresses. Although numerous studies have explored the consequences of cell damage due to hydrodynamic stress, there has been a lack of understanding of the mechanism of such damage at a cellular level. Cell damage can also influence biomedical applications. Cells manipulated in instruments such as diagnosis and analysis devices can experience hydrodynamic forces.

The level of cell damage is influenced by the hydrodynamic conditions in the bioprocess or biomedical equipment as well as the cell line sensitivity. To evaluate and compare cell sensitivity among different cell lines, a flow contraction device, previously designed by our group was used. Cells were exposed to well defined and controlled hydrodynamic forces and cell damage was estimated as a function of energy dissipation rate (EDR). EDR is a scalar value that represents the rate of dissipation of kinetic energy per unit of mass or volume. Using this methodology we found human cell lines highly sensitive to hydrodynamic forces.

Hydrodynamic evaluations were performed in ten different bioreactor configurations Impeller-Sparger. The best configurations were chosen based on kLa response surface model for testing in cell culture experiments. The configurations chosen were used to evaluate the expression of stress proteins under moderate hydrodynamic stress in bioreactors as well as cell cycle profile and its relationship to recombinant protein production. The results suggest that for a clonal cell line evaluated G1 phase of the cell cycle may be more conducive to producing the recombinant protein. In addition, a relationship between hydrodynamic stress and expression of stress proteins was observed. The type of stress protein and the level of expression seem to be dependent on cell type and differences could even be observed between clones of the same cell line.

Cell damage was also evaluated in a fluorescent activated cell sorter (FACS) models Vantage and Aria. Cells can be exposed to very high hydrodynamic forces when flowing through channels and nozzle in the sorting process. Results indicate that not only are cells damaged in a flow cytometer, but that this damage can vary from cell line to cell line as well as from specific conditions/type of flow cytometer and flow conditions. In addition, studies were conducted to evaluate cell growth behavior after stress as well as the effect of sorting on cell cycle. Extended growth lag phase was observed in cells exposed to hydrodynamic stress, and the sensitivity of any specific cell line can be a function of the growth phase of the cell

Committee:

Jeffrey Chalmers (Advisor); Jessica Winter (Committee Member); Andre Palmer (Committee Member); Lisa Libby (Committee Member)

Subjects:

Chemical Engineering

Keywords:

Mammalian cell culture; hydrodynamic stress; cell damage; shear stress; flow cytometry; CHO; THP1; bioreactors

Rahimi, Mohammad RezaDistributed Stress Sensing And Non-Destructive Tests Using Mechanoluminescence Materials
Doctor of Philosophy, University of Akron, 2015, Civil Engineering
Rapid aging of infrastructure systems is currently pervasive in the US and the anticipated cost until 2020 for rehabilitation of aging lifeline will reach 3.6 trillion US dollars (ASCE 2013). Reliable condition or serviceability assessment is critically important in decision-making for economic and timely maintenance of the infrastructure systems. Advanced sensors and nondestructive test (NDT) methods are the key technologies for structural health monitoring (SHM) applications that can provide information on the current state of structures. There are many traditional sensors and NDT methods, for examples, strain gauges, ultrasound, radiography and other X-ray, etc. to detect any defect on the infrastructure. Considering that civil infrastructure is typically large-scale and exhibits complex behavior, estimation of structural conditions by the local sensing and NDT methods is a challenging task. Non-contact and distributed (or full-field) sensing and NDT method are desirable that can provide rich information on the civil infrastructure’s state. Materials with the ability of emitting light, especially in the visible range, are named as luminescent materials. Mechanoluminescence (ML) phenomenon is the light emission from luminescent materials as a response of an induced mechanical stress. ML materials offer new opportunities for SHM that can directly visualize the stress and crack distributions on the surface of structures through ML light emission. Although material research for ML phenomena have been made substantially, applications of the ML sensors to full-field stress and crack visualization are still at infant stage and have yet to be full-fledged. Moreover, practical applications of the ML sensors for SHM of civil infrastructure have difficulties since numerous challenging problems (e.g. environmental effect) arise in actual applications. In order to realize a practical SHM system employing ML sensors, more research needs to be conducted, for examples, fundamental understandings of physics of ML phenomenon, method for quantitative stress measurements, calibration method for ML sensors, improvement of sensitivity, optimal manufacturing and design of ML sensors, environmental effects of ML phenomenon (e.g. temperature), image processing and analysis, etc. In this research, fundamental ML phenomena of two most promising ML sensing materials were experimentally studied and a methodology for full-field quantitative strain measurements, for the first time, was proposed along with a standardized calibration method. Characteristics and behavior of ML composites and thin films coated on the structure have been studied under various material tests including compression, tension, pure shear, bending, etc. In addition, ML emission sensitivity to the manufacturing parameters and experimental conditions was addressed in order to find optimal design the ML sensor. A phenomenological stress-optics transduction model for predicting the ML light intensity from a thin-film ML coating sensor subjected to in-plane stresses was proposed. A new full-field quantitative strain measuring methodology by ML thin film sensor was developed, for the first time, in order to visualize and measure the strain field. The results from the ML sensor were compared and verified by finite element simulation results. For NDT applications of ML sensors, experimental tests were conducted to visualize the cracks on structural surfaces and detect damages on structural components. In summary, this research proposes and realizes a new distributed stress sensor and NDT method using ML sensing materials. The proposed method is experimentally validated to be effective for stress measurement and crack visualizations. Successful completion of this research provides a leap toward a commercial light intensity-based optic sensor to be used as a new full-field stress measurement technology and NDT method.

Committee:

Gunjin Yun, Dr. (Advisor); Wieslaw Binienda, Dr. (Committee Member); Anil Patnaik, Dr. (Committee Member); Gary Doll, Dr. (Committee Member); Jianhua Zhu, Dr. (Committee Member); Ali Hajjafar, Dr. (Committee Member)

Subjects:

Civil Engineering; Materials Science; Mechanical Engineering; Mechanics; Optics; Physics

Keywords:

Mechanoluminescnece, Non-Destructive Test, Image Processing, Health Monitoring, Full-Field Stress Sensor, Stress Optic Sensor

Chong, AlexandraHome and Work Stress Spillover: The Roles of Social Support and Positive Reappraisals
PHD, Kent State University, 2016, College of Arts and Sciences / Department of Psychology
Prior work has shown that stress from home and work domains can spill over onto one another (Bolger, DeLongis, Kessler, & Wethington, 1989). Although the stress spillover relationship has been established, it is unknown what may moderate this association. Two potential moderators that have been shown to be helpful in buffering the potentially harmful effects of stress are social support (Cohen & Wills, 1985) and positive reappraisals (Jamieson, Berry Mendes, & Nock, 2013). To test the moderating roles of social support and positive reappraisals in stress spillover, two studies were conducted. In Study 1, data from a national daily diary data set, the National Survey of Daily Experiences (NSDE II; Ryff & Almeida, 2004) was utilized. Based on daily telephone interviews from 330 participants, results provided evidence for home-to-work spillover, but not work-to-home spillover. However, on days when family support was received, greater work stress was related to less home stress, but overall perceived family support exacerbated home-to-work spillover effects. Study 2 tested how experimental manipulations of reappraisals of home and work spillover affect daily spillover effects. In Study 2, 127 participants recruited from an online surveying site (Amazon’s Mechanical Turk) were instructed to reappraise home and work spillover as positive, negative, or were placed in a control condition and completed a 10 daily diaries assessing their home and work stressors. Results indicated that only for individuals in the control condition, greater work stress was related to less home stress. For individuals in the negative and positive reappraisal conditions, work stress was not related to home stress. The control condition and the positive reappraisal condition did not significantly differ from one another in work-to-home spillover. Together, findings from Study 1 and 2 suggest that individuals may experience less home stress on days when they have high work stress, and that receiving family support could contribute to this form of domain compensation.

Committee:

Judith Gere, PhD (Advisor); John Updegraff, PhD (Committee Member); Jeffrey Ciesla, PhD (Committee Member); Mary Ann Stephens, PhD (Committee Member); Kristin Mickelson, PhD (Committee Member); Kristen Marcussen, PhD (Committee Member)

Subjects:

Experimental Psychology; Families and Family Life; Psychology

Keywords:

stress; stress spillover; social support; positive reappraisals

Figueiredo, Helmer FeitosaThe Effects of a Brief Mindfulness Induction on Affective and Behavioral Responses to Psychosocial Stress
Doctor of Psychology (Psy.D.), Xavier University, 2016, Psychology
This study proposed to examine whether a brief, 15-minute focused breathing induction, a model of mindfulness, significantly impacted the affective and behavioral responses to a social stressor. To address this question, 43 undergraduate students from a Midwestern university participated in this study. These participants were randomly assigned to one of the following three experimental groups: focused breathing induction, worry induction, and unfocused attention (control) groups. Each participant listened to only one of the three inductions for 15 minutes, according to their assigned group. Following exposure to their induction, participants were then exposed to the Trier Social Stress Test (TSST), a model of psychosocial stressor. Throughout the study, participants completed measures of affect at different time-points. Speech and math performance data were also collected as behavioral measures during the TSST. In contrast to findings from the literature, results from this study indicated that there were no statistically significant differences in emotional and behavioral responses to the psychosocial stress among the induction groups. The present findings are discussed in the context of its limitations and future studies are proposed.

Committee:

Nicholas Salsman, Ph.D. (Committee Chair); Kathleen Hart, Ph.D. (Committee Member); John Barrett, Ph.D. (Committee Member)

Subjects:

Psychology

Keywords:

mindfulness, worry, stress, affect, emotion, PANAS, Trier Social Stress Test, induction

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