Path selection and generating tests for small delay faults is an important issue in the delay fault area. A novel technique for generating effective vectors for delay defects is the first issue that we have presented in the thesis. The test set achieves high path delay fault coverage to capture small-distributed delay defects and high transition fault coverage to capture gross delay defects. Furthermore, non-robust paths for ATPG are filtered (selected) carefully so that there is a minimum overlap with the already tested robust paths. A relationship between path delay fault model and transition fault model has been observed which helps us reduce the number of non-robust paths considered for test generation. To generate tests for robust and non-robust paths, a deterministic ATPG engine is developed. To deal with small delay faults, we have proposed a new transition fault model called As late As Possible Transition Fault (ALAPTF) Model. The model aims at detecting smaller delays, which will be missed by both the traditional transition fault model and the path delay model. The model makes sure that each transition is launched as late as possible at the fault site, accumulating the small delay defects along its way. Because some transition faults may require multiple paths to be launched, simple path-delay model will miss such faults. The algorithm proposed also detects robust and non-robust paths along with the transition faults and the execution time is linear to the circuit size. Results on ISCAS'85 and ISCAS'89 benchmark circuits shows that for all the cases, the new model is capable of detecting smaller gate delays and produces better results in case of process variations. Results also show that the filtered non-robust path set can be reduced to 40% smaller than the conventional path set without losing delay defect coverage. / Master of Science

Clay composition and content profoundly impacts the strength and sealing capacity of a fault zone, reducing frictional resistance to sliding and permeability by as much as 7 orders of magnitude. Previous approaches, including the Shale Gouge Ratio (SGR) and Shale Smear Potential (SSP), have been used to understand and predict the clay content of fault zones. These models are largely limited to mechanical incorporation of detrital clays. This hypothesis stems from field observations of clay gouge and the smearing and associated attenuation of clay-rich shale beds offset by the fault. Recently, diagenesis has been recognized as an additional critical mechanism of clay enrichment In fault zones. My study investigates the relative contributions of both mechanisms of clay enrichment focusing on the implications for fault permeability and strength through structural and elemental mapping of the Moab Fault in Utah. Detailed mapping at Six sites along the Moab Fault in southeast Utah, revealed distinct structural deformation zones as defined by structures and distribution of normally faulted sandstone and shale including: (1) layers of clay-rich gouge separated by slip surfaces that include isolated sandstone breccia; (2) an inner smeared shale adjacent to the gouge showing increasing bed parallel shearing and resulting boudinage closer to the fault, and an outer smear with little shearing but rotation of beds; (3) faulted sandstone hosting deformation bands, slip surfaces, and intersections, joints and veins in locations near relays. Fluid assisted alteration was revealed by a combination of high spatial resolution scan-lines on outcrops element composition and measured sections of measured with a portable X-Ray Fluorescence device. Results to date include: (1) elemental concentrations relative to immobile species (such as Ti) and by structural zone show that Ca, Sr, Rb are preferentially enriched and/or depleted in the fault core, (2) the fault core hosts the greatest alteration; (3) a progressively more extensive and greater density of bed parallel slip surfaces from protolith to gouge where slip surfaces are associated with mixing and disaggregation; (4) stable concentration of elements associated with illite such as K, occurs preferentially in the gouge; (5) localized enrichment and/or depletion reveals solution mass transfer contributed to formation of the fault core and to a lesser extent the damage zones. Elemental mapping clearly demonstrates a compositional evolution of the fault core, and in particular the clay gouge, that cannot be accounted for by mixing of protolithic formations. Thus, observations from elemental mapping show that solution mass transfer influences the formation of clay gouge in the fault zone, in addition to mechanical incorporation of detrital clays from the surrounding protoliths. / Earth and Environmental Science

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No description available.

Thesis. 1976. Sc.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences. / Microfiche copy available in Archives and Science. / Bibliography: leaves 208-213. / Sc.D.

Thesis. 1977. M.S.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences. / Microfiche copy available in Archives and Science. / Bibliography : leaves 34-39. / by Norman C. Burr. / M.S.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1981. / Microfiche copy available in Archives and Science. / Vita. / Bibliography: leaves 91-93. / by Lucile Merrill Jones. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Science, 1982. / Microfiche copy available in Archives and Science. / Two maps and one illustration on 3 folded leaves in pocket. / Includes bibliographies. / by Brian Philip Wernicke. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1979. / Microfiche copy available in Archives and Science. / Bibliography: leaves 73-75. / by Steven J. Hellinger. / Ph.D.

Folding prior to thrust-sheet emplacement is proposed to explain presence of overturned synclines in the footwalls of many thrust-faults in the Appalachian foreland fold- and thrust-belt of southwest Virginia. Investigation of relations in the footwalls of the Saltville and St. Clair thrust-sheets near the Southern-Central Appalachian juncture indicates presence of at least two distinct types of footwall structures: 1)isolated forelimbs of thrust-truncated asymmetric ramp-generated anticlines, and 2)areally extensive overturned subthrust synclines. Mesoscopic fabric data and strain states indicate rotation of bedding by folding prior to thrust-sheet emplacement rather than drag folding during thrusting. Low angles between bedding and cleavage planes and low strain values on the back limbs of folds at thrust terminations (Sinking Creek anticline) and in hangingwall strata seems to indicate folding was largely accomplished by flexural flow in units of relatively low mechanical strength. / M.S.