Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 265 for “"seals"”.
-
Soil ingestion by elastomeric seals
… ingestion precede seal erosion, and that seals designed to interfere with each stage exhibit substantially longer operational life. The three stages of failure preceding seal erosion are as follows. The first stage occurs when small soil particles creep into the contact gap. These …
-
Mechanics of swellable elastomeric seals
… the mechanics of swellable elastomeric seals for the purpose of hydraulic fracturing in oil and gas applications. The first component of the thesis is the development of a laboratory-scale apparatus for the visualization of swellable seals in situ up to the point of leakage. Experiments …
-
Investigation of reverse plumbing in rotary seals
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2003.
-
Glass-ceramics for solid oxide fuel cell seals
<p>"This dissertation is comprised of five sections. The first section includes a review of the literature on the development of glass and glass-ceramic sealants for solid oxide fuel cells (SOFC), including the critical issues for sealant design. Section two describes a quantitative approach to …
-
Numerical Modeling of Air Cushion Vehicle Flexible Seals
Air cushion vehicle flexible seals operate in a complex and chaotic environment dominated by fluid-structure interaction. An efficient means to explore interdependencies between various governing parameters that affect performance is through high fidelity numerical simulation. As previous numerical …
-
Vocal communications among Harbor Seals (Phoca vitulina) on land
… types being used in haul outs by harbor seals in Iceland and how vocalization parameters and rates may be influenced by the surroundings using data collected in the summer of 2022. Six vocalization types were determined across the three biological periods (pupping, feeding, …
-
Temperature and microbial destruction conditions in flexible package seals
Thesis (M.S.)--Michigan State University. Dept. of Food Science, 1966
-
Quality Assurance for Chip Seals Using Mean Profile Depth
… metric for the quality assurance of chip seals. Field data were collected using state-of-the-art equipment from the Virginia Department of Transportation (VDOT) area. Considering both qualitative (visual assessment) and quantitative (MPD analysis) approaches, this study delineates …
-
Navy SEALS - Crossing Cultures: Cross-Cultural Competence and Decision Styles
… of experienced Navy Sea, Air, and Land Forces (SEALs) to distinguish between cross-cultural superior and substandard scorers. Logistic regression analysis was then used to estimate relationships between several demographic and decision-style factors and individual scores in cross-cultural …
-
Dispersal and dispersion of southern elephant seals at Marion Island
… dispersal and dispersion of southern elephant seals, Mirounga leonina, at Marion Island in relation to their natal site, and to their site of first reproduction. Movements from the natal site to terrestrial haulouts used for reproduction, and between successive reproductive sites, were defined …
-
Trophic role of small cetaceans and seals in Irish waters
… sympatric species might occur. Both species of seals were found to have a high overlap (more than 80%) in their diet composition, but while grey seals feed on large fish (>110mm), harbour seals feed mostly on smaller fish (<110mm), suggesting some spatial segregation in foraging. Harbour …
-
The performance of high speed reciprocating polymer seals in water
… lubrication of polymeric piston seals in a water powered rockdrill has been modelled in this thesis. Current seal designs, consist of an Ultra High Molecular Weight Polyethylene (UHMWPE) ring, energised to remain in contact with the reciprocating piston, using a nitrile rubber …
-
Experimental evaluation of effective friction coefficient for liquid ring seals
Rotor dynamic analysis of liquid ring seals depends upon the correct specification of seal dynamic stiffness and damping characteristics. These are in turn dependent upon several parameters, including the friction holding force between the sealing face and the mating retaining ring. Designers …
-
Exploring the Social Lives of Cylinder Seals in Late Cypriot Society
This thesis examines how cylinder seals became socially embedded in Late Bronze Age Cyprus. Although these objects appear throughout the Near East and Mesopotamia at the time, their use in Cyprus appears unique. To explore this, cylinder seals are studied according to funerary, sanctuary and …
-
Becoming Artifacts: Medieval Seals, Passports and the Future of Digital Identity
… digital identity token have to do with medieval seals? Is the history of passports of any use for enabling the discovery of Internet users' identity when crossing virtual domain boundaries during their digital browsing and transactions? The agility of the Internet architecture and its simplicity …
-
Considering behaviour in genetic sampling – a case study with grey seals
… Buccal swabs were tested in a group of grey seals in a rehabilitation centre. The swabs showed potential for being able to carry out individual genotype analysis to identify polymorphisms; a SNP in the grey seal DRD4 gene not previously reported in any other studies was found. However, some …
-
Entanglement of Cape Fur Seals (Arctocephalus pusillus pusillus) in South Africa
… 1997 onwards. Overall, 314 cases of entangled seals were identified. As calculated from the systematic surveys, Baboon Point in Elands Bay (0.24% ± 0.78%, n = 7, with a 95% confidence interval) had the highest entanglement incidence. Seal Island in False Bay had the highest overall number of …
-
Lifetime Prediction and Durability of Elastomeric Seals for Fuel Cell Applications
… of the FC. The elastomeric gaskets used as FC seals are exposed to a range of environmental conditions, and concurrently, subjected to mechanical compression between the bipolar plates forming the cell. The combination of mechanical stress and environmental exposure may result in degradation of …
-
Analysis of tilting-pad oil seals for high pressure centrifugal compressors
Oil ring seals are one major source of instability in high pressure centrifugal compressors. This thesis presents a method for analysis of an improved seal concept that has been used in very high pressure designs (900 PSI). The improved design uses a combination of ring seals and tilting pad …
Page 1 of 14