A Balanced Diaphragm Type of Maximum Cylinder Pressure Indicator

A balanced diaphragm type of maximum cylinder pressure indicator was designed to give results consistent with engine operating conditions. The apparatus consists of a pressure element, a source of controlled high pressure and a neon lamp circuit. The pressure element, which is very compact, permits location of the diaphragm within 1/8 inch of the combustion chamber walls without water cooling. The neon lamp circuit used for indicating contact between the diaphragm and support facilitates the use of the apparatus with multicylinder engines

A search for layering in the oceanic crust

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution October 1988The results of numerous seismic refraction and reflection experiments have shown that the seismic structure of the oceanic crust can be usefully parameterized by a small number of locally horizontal layers within which the rates of change of velocity and impedance as a function of depth are approximately constant. Layer boundaries are defined by changes in velocity and/or impedance gradient. This dissertation discusses the structure of seismic layer boundaries within the oceanic crust, and investigates the relationships between the seismic characteristics of these boundaries and the geological structure of the crust. The seismic signature of the crust/mantle boundary (Moho) is a prominent event on multichannel seismic (MCS) reflection data. In the Western North Atlantic, the character of the Moho reflection event varies from a single well-defined phase to a more complex event consisting of two or more overlapping phases of up to 1.0 s total duration. In Chapter 1 of this dissertation, the geological structures generating Moho reflections are investigated by calculating synthetic reflection profiles for three laterally varying velocity models totaling 64 km in length. These velocity models were derived from the observed distribution of lithologies that comprise the inferred fossil crust/mantle transition found in the Bay of Islands Ophiolite. Along the synthetic profiles, the Moho reflection is characterized by both single-phase and multi-phase events, the geometry and durations of the latter being similar to those observed on MCS data from the Western North Atlantic. In addition, the lateral variation in Moho travel time, up to 0.25 s over distances of less than 10 km, is similar to that observed on MCS data. The similarities between the observed and synthetic data suggest that the complicated interlayered sequences of mafic and ultramafic rocks that comprise the inferred crust/mantle transition in ophiolites might also be characteristic of the oceanic crust. Although ophiolites provide a useful model of the lithological structure of the oceanic crust, the unambiguous correlation of geologic and seismic structures can only be achieved by conducting seismic experiments in the vicinity of deep crustal drillholes. Chapters 2 and 3 of this dissertation present analyses of the velocity and reflectivity structure of the crust in the immediate vicinity of Deep Sea Drilling Project Hole 504B in the Panama Basin, currently the deepest drillhole (1.288 km) into oceanic igneous crust. Reflectivity synthetic seismogram modeling of amplitude features common to four sonobuoy profiles collected in the immediate vicinity of Site 504B shows that crustal thickness at the drillsite is only 5 km. A critical constraint on this interpretation is the observation, on four MCS profiles passing through the drillsite, of a near-normal-incidence reflection event with a crustal travel time of 1.4-1.5 s. This event is assumed to correlate with a wide-angle reflection/refraction event observed at ranges of 16-28 km on the sonobuoy profiles. Seismic modeling demonstrates that both of these events are generated at the Moho. The crustal velocity-depth profile at Site 504B is unusual in comparison to typical oceanic profiles in having high velocity gradients (up to 0.6 km s- 1 km- 1 ) in the middle crust and a 1.8 km thick low-velocity zone (Vp=7.1-6.7 km s- 1 ) immediately above Moho. A simple explanation for this unusual profile is that the velocity of the middle crust has been increased by the addition of a high-velocity mineral component such as olivine. The olivine concentration of the middle crust need be no greater than 34-37%. Hole 504B is the only site where the volcanics/sheeted-dike boundary, predicted by the ophiolite model to Qe a fundamental feature of oceanic crust, has been drilled. The downward change in rock type coincides with changes in a variety of logged physical properties. The normal-incidence travel time to this boundary is similar to the travel times of shallow reflection events observed in other areas. Accordingly, Site 504B is an ideal location to test the hypothesis that shallow reflection events correlate with the extrusives/dike boundary. Despite extensive processing, MCS data collected 'in the immediate vicinity of Hole 504B show no conclusive evidence for a laterally coherent reflection event generated within the upper crust. The lack of a detectable reflection event from the upper crust is consistent with the results of synthetic seismogram modeling of velocity-depth profiles constructed from the logged downhole variation in physical properties. On these normal-incidence synthetic seismograms, low-amplitude reflections from the volcanic/dike contact are obscured by the high-amplitude basement reflection and by sediment-column multiples. In contrast to the synthetic reflection data, the seismic signature of the volcanics/dike boundary is readily recognizable on a synthetic wide-angle reflection/refraction profile. The change in velocity across this boundary causes focusing of refracted arrivals in the range window 6-7 km. High-amplitude arrivals are observed at similar ranges on the sonobuoy profiles collected near the drillsite, suggesting that at Site 504B, variations in depth to this layer boundary are more easily mapped with the wide-angle reflection/refraction method.The work described in this dissertation was funded by the following National Science Foundation grants: OCE-81-17210, EAR-80-26445, EAR-83-9535, OCE-80-25206, OCE-84-10658, and OCE-87-00806

Measuring transversity densities in singly polarized hadron-hadron and lepton-hadron collisions

We show how the transverse polarization of a quark initiating a jet can be probed by the azimuthal distribution of two hadrons (of large $z$) in the jet. This permits a twist 2 asymmetry in hard processes when only one of the initial particles is polarized transversely. Applications to hadron-hadron and lepton-hadron scattering are discussed.Comment: 16 pages, LaTeX + EPSF, 2 postscript figures. PSU/TH/10

An Assessment of Community Health Needs Assessment (CHNA) Data Collection Related to Building Capacity for Sexual and Gender Marginalized (SGM) Individuals in Health Care Organizations

This research examines LGBTQ+ data collection for Community Health Needs Assessments (CHNA) by Wisconsin Health care organizations as mandated by the Affordable Care Act, and whether data collection considered LGBTQ+ populations. If collected, it assesses what types of LGBTQ+ data was collected and how it was used and/or reported in the CHNA. Furthermore, a comparison by location (rural/urban) regarding whether there is a difference in likelihood that a health care organization would collect LGBTQ+ data. The results of this study indicate that data collection is collected by approximately one-quarter of Wisconsin health care organizations for the purpose of their CHNAs and there is not a significant difference by location regarding inclusion of LGBTQ+ data

Proposal for the Creation of a Subdiscipline: Education Informatics

“Education Informatics” is the name for an emerging new sub-discipline of education. We define “Education Informatics” as the application of technology to discovering and communicating education information. This article will provide an historical and theoretical foundation for the emergence of this new sub-discipline. Existing definitions of informatics, the literature on education informatics, and the evolution of academic disciplines will be examined. The authors will explore commonalities between the two disciplines from which education informatics is derived: information science and education. They will justify the foundation of the sub-discipline, grounding it within the existing discipline of education. The article will conclude with a discussion of how this new sub-discipline might impact research and practice; a plan for incorporating the new sub-discipline in the educational system; and a proposed research agenda

Millimeter-level precision in a seafloor geodesy experiment at the Discovery transform fault, East Pacific Rise

Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 14 (2013): 4392–4402, doi:10.1002/ggge.20225.Direct-path acoustic ranging is a promising seafloor geodetic technique for continuous high-resolution monitoring of geodynamical process such as fault slip and magma intrusion. Here we report on a yearlong acoustic ranging experiment conducted across the discovery transform fault at ∼4°S on the East Pacific Rise. The ranging instruments utilized a novel acoustic signal designed to enhance precision. We find that, after correcting for variations in sound speed at the path end-points, the ranging measurements have a precision of ∼1 mm over baselines approaching 1 km in length. The primary difficulty in this particular experiment was with the physical stability of the benchmarks, which were deployed free fall from a ship. Despite the stability issues, it appears that the portion of the transform fault that the array covered was locked during the year of our survey. The primary obstacle to continuous, high sample rate, high-precision geodetic monitoring of oceanic ridges and transform faults is now limited to the construction of geodetic monuments that are well anchored into bedrock.This research was funded by the National Science Foundation OCE division under award 0351143.2014-04-0

Pn anisotropy beneath the South Island of New Zealand and implications for distributed deformation in continental lithosphere

Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 119 (2014): 7745–7767, doi:10.1002/2014JB011233.Pn travel times from regional earthquakes recorded both by stations on New Zealand and by ocean bottom seismographs deployed offshore indicate anisotropy in the uppermost mantle beneath the region. The largest anisotropy of ~8% (±2%, 1σ) lies beneath the deforming part of the South Island to just off its West Coast, a zone roughly 100–200 km wide. The fastest propagation is aligned N60°E (±3°), essentially parallel to the largely strike-slip relative plate motion since 20 Ma, also ~ N60°E. The magnitude of anisotropy decreases abruptly northwest and southeast of this zone, and on the southeast side of the island, the orientation of fastest propagation is between N32°W and N-S. The ~ N60°E orientation of fast propagation is consistent with finite strain within the uppermost part of the mantle lithosphere if the measured 850 km of displacement of the Pacific plate past the Australia plate is spread over a region with a width of 100–200 km. The agreement of this orientation of fast propagation with the orientation or relative plate motion suggests the possibility of but does not require some dynamic recrystallization in rock as cold as 500–800°C, where Peierls creep seems to be the likely deformation mechanism. Such a strain distribution matches deformation of a thin viscous sheet that obeys a constitutive relationship of the form inline image, where inline image is the average strain rate and τ is the operative deviatoric stress, with an average value of n ≈ 3–10. Presumably, the NW-SE fast propagation in the region southeast of the island results from strain that precedes the Cenozoic deformation that has shaped the island.This research was supported by the National Science Foundation under grants EAR-0409564, EAR-0409609, and EAR-0409835.2015-04-2