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.
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Showing 1 to 20 of 26 for “"LWD"”.
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Design and Fatigue Analysis of an LWD Drill Tool
… from Halliburton’s previous works for the LWD drill tool to better estimate the size of the largest possible transducer. The fatigue analysis of static load cases is carried out in Ansys Mechanical Workbench 19.0 using static structural analysis. The simulation is run to obtain results for …
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A comparison of logging while drilling (LWD) and wireline acoustic measurements
… as either wireline or logging while drilling (LWD). The wireline tool measures formation speeds after the borehole is drilled, and the LWD tool measures formation speeds while the borehole is drilled. This thesis focuses on comparing the data collected by these tools and how formation …
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Numerical modeling of borehole acoustics : parallel implementation of a loggin-while-drilling (LWD) model
… The wave response to a logging-while-drilling (LWD) geometry is modeled in a fast formation. Helical waves circling the tool are shown to asymptote to the Stoneley wave velocity, giving confirmation of the fluid velocity in the borehole. Parameter studies for simpler borehole geometries show …
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A study of seismoelectric signals in measurement while drilling
An LWD acoustic wave can move the excess charge in the electric double layer along the borehole wall to generate a streaming electric field. This thesis is an experimental and theoretical investigation of the electric field induced by the multipole LWD acoustic wave. The main goal of this thesis is …
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Relations between large woody debris, physical habitat, and benthic macroinvertebrates in Appalachian mountain streams
Large woody debris (LWD) was added to North Fork Stony Creek and North Prong Barbours Creek as an experimental stream enhancement technique. The purpose of this study was to determine the stream channel responses to LWD additions at the scale of the stream reach and around individual logs, to …
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Effects of Two Backpack Weight Distributions on Perceptual and Physiological Measures During Walking
… the shoulders, and a low weight distribution (LWD) (1:1:3 ratio) placing more weight near the hips. Heart rate (HR), RPE-Overall, RPE-Legs, RPEShoulders, and RPE-Back were recorded every three minutes and compared between trials using repeated measures ANOVA. HR between HWD and LWD was similar …
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Evaluation of Red Alder Mortality in the Little Creek Watershed Following the 2009 Lockheed Fire
… An estimation of red alder large woody debris (LWD) input to Little Creek since a 2010 LWD survey (Smith, 2010) was calculated using average red alder tree dimensions applied to Smalian’s formula (MLNRO, 2011). The mean proportion of dead red alder in the non-burn zone and burn-zone was .11 and …
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Impacts of Laurel Wilt Disease on Redbay (Persea Borbonia) Population Structure and Forest Communities in the Coastal Plain of Georgia, USA
Laurel wilt disease (LWD), a fungal disease vectored by the non-native redbay ambrosia beetle (Xyleborus glabratus), has caused mortality of redbay (Persea borbonia) in the Coastal Plain of Georgia, USA, since 2003. This disease has spread 30-100 km/year and little research has evaluated its …
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Detecting Change in Central California Coast Coho Salmon Habitat in Scotts Creek, California, from 1997–2013
… junctions. Although a large woody debris (LWD) survey was not conducted as part of the 1997 survey, contrasting our results with data collected during intervening years indicated that instream LWD has become more abundant, primarily due to increases in hard-wood species (i.e., red alder …
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Himalayan Blackberry (Rubus armeniacus) Effects on Fish Habitat: Impacts from Riparian Zones Inundated with Himalayan Blackberry
… rearing habitat for fish (large woody debris (LWD) habitat and residual pool habitat). I hypothesized that each fish habitat quality indicator would show lower quality in the test sites compared to the reference sites. My findings indicate that test sites had lower canopy cover, in comparison …
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Short-term response of physical habitat and fish to the addition of large woody debris in two Appalachian Mountain streams
Large woody debris (LWD) was added to North Fork Stony Creek and North Prong Barbours Creek in southwest Virginia to inlprove fish habitat. The purposes of this study were to monitor stream channel response to the addition of LWD at a stream reach scale and at a local scale around individual logs, …
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Recovery From and Effects of a Catastrophic Flood and Debris Flow on the Brook Trout (<i>Salvelinus fontinalis</i>) Population and Instream Habitat of the Staunton River, Shenandoah National Park, VA
… substrate composition, and large woody debris (LWD) before (1993), immediately following (1995), and four years post-event (1999). Immediately following the debris flow, the stream channel was highly disordered which resulted in an increase in the total number of habitat units and a decrease in …
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Influence of riparian vegetation on near-bank flow structure and rates of erosion on a large meandering river
… the effects of near-bank large woody debris (LWD) on near-bank flow structure and boundary shear stress, and how the hydrodynamics varied during different hydrologic conditions. Data consist of time-averaged three-dimensional velocity measurements, which were obtained using a boat-mounted …
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Watershed and Streamside Management Zone Characterization in the Allegheny Plateau of West Virginia
… loss of 10.9 Mg/ha/yr. In-stream and SMZ LWD volume was approximately equal at 28 and 33 m3/ha. Large woody debris was more decayed in the SMZ than in-stream LWD.
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Predicting Multi-trophic Consequences of an Emerging Disease
… In the southeastern US, laurel wilt disease (LWD) is impacting numerous species in the Lauraceae family, with the majority of cases observed on Persea borbonia, a common sub-canopy tree found in many Coastal Plain habitats. This species is also known to be the primary larval host of the …
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Geology, surface hydrology, and fish habitat relationships in the upper Shavers Fork drainage basin, West Virginia
… relative abundance of large woody debris (LWD).;In-stream heterogeneity dominates pools and channel-unit complexes, which comprise 69 percent of the total stream area. In-stream homogeneity dominates riffles and glides which constitute 31 percent of the total stream area.
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Asymmetric radiant fields and human thermal comfort
… cold discomfort (LCD) and local warm discomfort (LWD) which are based on different physiological principles - were modelled as two separate responses. LCD was found to be a function of the sensitivity-weighted local skin temperature as related to the actual general thermal state of the human body …
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THE EFFECTIVENESS OF TROUT HABITAT RESTORATION IN EUSTACHE CREEK, A FORMERLY PLACER-MINED STREAM IN WESTERN MONTANA
… quality in this study were percent pool habitat, LWD frequency and LWD median diameter. Recommendations for future monitoring include: 1) continue monitoring for the next 15-20 years, 2) collect more pre-project data, 3) increase the number of sampling sites, 4) maintain consistency in sampling …
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THE EFFECTIVENESS OF TROUT HABITAT RESTORATION IN EUSTACHE CREEK, A FORMERLY PLACER-MINED STREAM IN WESTERN MONTANA
… quality in this study were percent pool habitat, LWD frequency and LWD median diameter. Recommendations for future monitoring include: 1) continue monitoring for the next 15-20 years, 2) collect more pre-project data, 3) increase the number of sampling sites, 4) maintain consistency in sampling …
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Time-Lapse Variations of Multi-Component Electrical Resistivity Measurements Acquired in High-Angle Wells
… anisotropy are becoming increasingly popular in LWD and open-hole environments. At the same time, field experience indicates that invasion and time of logging can have a significant effect on multi-component induction measurements acquired in high-angle wells, specifically in the presence of …
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