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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

EXPERIMENTS AND MODELING ON THE STRESS RELAXATION NEAR A NOTCH IN ZR-2.5NB

Wan, SHUAI 20 September 2012 (has links)
As an important structural component in CANDU reactor, the pressure tube, made of coldworked Zr-2.5Nb, experiences a neutron flux under high pressure and elevated temperature during the reactor operation. Notches, existing as defects in the pressure tube, are usually the location where stress concentration and crack initiation happens, which seriously degrade the performance of the pressure tube. However, the concentrated stress at the notch area is expected to be relieved by thermal creep, reducing the possibility of crack occurrence. In this study, synchrotron X-ray diffraction experiments were conducted to collect the lattice strains near the notch in both irradiated and unirradiated Zr-2.5Nb samples which had experienced a thermal creep process for different time periods. Strain maps of the notch area were created for each sample. Stress relaxation over the time is discussed for both parallel and perpendicular to the loading direction and also compared between {10 -10} and {0002} orientations. A FE model was set up for the unirradiated materials, which was verified by the experimental results. This work provides an understanding of the stress relaxation near a notch in Zr-2.5Nb and the stress/strain distribution during the thermal creep, which provides valuable information on the assessment of the reactor operation. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2012-09-20 19:39:30.593
2

Influence of stress relaxation on watertight integrity of hybrid bolted joints /

Pelletier, Keith N., January 2003 (has links) (PDF)
Thesis (M.S.) in Mechanical Engineering--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 97-98).
3

Relaxation training and blood pressure reponses to experimental stress

English, Eric Harold. January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1981. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 81-91).
4

Influence of Stress Relaxation on Watertight Integrity of Hybrid Bolted Joints

Pelletier, Keith N. January 2003 (has links) (PDF)
No description available.
5

The effects of material characteristics on the compression and properties of dry coated tablets

Thomas, William Iwan January 1998 (has links)
No description available.
6

The effects of auditory subliminal psychodynamic activation on state anxiety / Auditory subliminal psychodynamic activation on state anxiety.

West, G. Norman January 1984 (has links)
Most of the recent research in the area of subliminal perception has centered on the visual mode of stimulus presentation. The preponderance of that research is concerned with a technique that is hypothesized to stimulate the activation of an unconscious symbiotic merging fantasy which is purported to have an ameliorative effect on pathology. The present study explored the possibility of a merging-like fantasy activation through auditory subliminal means utilizing a population, of 30 VA inpatients with the diagnosis of generalized anxiety disorder. In a double blind procedure, the subjects received three successive treatments with scores analyzed for significance by multivariate and trend analysis. Dependent variables consisted of Form X-1 of the State-Trait Anxiety Inventory, and the physiological measure of skin temperature. It was hypothesized that the auditory mode of psychodynamic activation would prove effective and that there would be a significant reduction in state anxiety. The results of this study did not support the specific effectiveness of auditory subliminal psychodynamic activation for the treatment of generalized anxiety disorder. Self-report of perceived state anxiety decreased significantly for both the treatment and control groups as measured by the STAI, and there was a significant trend in the temperature data for both groups. There were, however, no significant differences between the two groups.
7

Quantification of the Elastic and Relaxation Properties of Human Tunica Albuginea under Biaxial Loading

Hou, Sindy Siyuan 20 September 2019 (has links)
Peyronie's disease (PD) affects the tunica albuginea of the penis with a formation of dense and fibrous plaques. The plaques can cause a variety of symptoms in the patient such as pain during erection, erectile dysfunction, and penile disfigurement. There are many treatment options available, though none without disadvantages. Quantification of the material properties of the tunica tissue can inform potentially improved treatments. In this study tunica tissue (n=5) from donors were tested biaxially along the circumferential and longitudinal directions to a specified load magnitude and maintained at a fixed displacement for 30 minutes to allow for stress relaxation. The loading and relaxation were then repeated for a second time. Stiffness, Young's Modulus, strain at inflection point between the toe region and linear region on the stress-strain curve, as well as percent stress relaxation after 30 minutes were compared between anatomic directions and ramp number. Only stiffness and percent relaxation showed a statistically significant difference between ramps 1 and 2, regardless of direction (p = 0.012). The results from this study report the baseline data of the biaxial mechanical properties of the tunica albuginea to be used for future comparisons to the properties of PD and graft tissue. / Master of Science / Peyronie’s disease (PD) affects a layer of tissue in the penis known as the tunica albuginea. Dense and fibrous plaques form on this layer which can cause pain during erection, erectile dysfunction, and penile disfigurement. There are many treatment options available, though none without disadvantages. In this study tunica tissues from donors were tested in order to find the material properties of the tissue to improve treatments. The tissue samples were pulled in tension in two directions simultaneously to a specified load magnitude and then held at a fixed displacement for 30 minutes. This protocol was then repeated a second time. The material properties of the tissue were compared between the anatomic directions of the tissue was well as protocol number. The results from this study report the baseline data of the biaxial mechanical properties of the tunica albuginea to be used for future comparisons to the properties of PD and graft tissue.
8

Relaxation of steel cables employed in pre-stressed concrete

Dill, Harold Dean. January 1957 (has links)
Call number: LD2668 .T4 1957 D57 / Master of Science
9

Stress relaxation of Zircaloy-4.

Minar, Arthur Phillip January 1976 (has links)
Thesis. 1976. B.S.--Massachusetts Institute of Technology. Dept. of Materials Science and Engineering. / Microfiche copy available in Archives and Science. / Includes bibliographical references. / B.S.
10

Low-level birefringence methods applied to the characterization of optical fibers and interconnects

Montarou, Carole Claudette. January 2005 (has links) (PDF)
Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2005. / Phillip First, Committee Member ; Gee-Kung Chang, Committee Member ; John Buck, Committee Member ; Glenn Smith, Committee Member ; Thomas Gaylord, Committee Chair. Includes bibliographical references.

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