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Testing geologic and geometric effects on drilling operations using torque and drag models
Intuitively, geologic and geometric effects on torque and drag should be significant. But literature suggests otherwise. Lesage et al. (1988) wrote that friction coefficients are not affected by lithology and hole angle, among other things. And if friction coefficients are similar for all of these factors, then only inclination, azimuth, and pipe specifications affect torque and drag. My thesis looks to test this statement using Johancsikâs torque and drag model and data provided by our sponsors. Johancsikâs model was chosen to test these effects because it is the most widely used torque and drag model in industry. Johancsikâs model also only relies on surface data in order to conduct an analysis. This contributes to the widespread use of Johancsikâs model and therefore increases the applicability of this paper. Once Johancsikâs model was chosen, it became natural to choose the minimum curvature method to interpolate the wellbore trajectory because Johancsikâs model was designed using the minimum-curvature method. Also, the minimum curvature method is the most widely used wellbore-interpolation method in industry. By using the minimum curvature method, this paper increases its applicability to industry. The analyses were conducted by examining the friction coefficients of each individual formation and lithology and geometric section. Friction factors encompass all factors that are not explicitly captured by the model and any factors affecting torque and drag that are not in the model will be captured by the friction factors. This study found lithology effects to affect drag consistently, though more data is needed. Drag friction factors were consistent by lithology, though they did appeared less predictable in Dataset 1 than the Datasets 2 and 3. Lithology affected torque less consistently than it did drag, though again more data is needed. Again, the results from Dataset 1 appeared to differ from Datasets 2 and 3. Further analyses are needed to conclude if this is caused by factors unrelated to lithology or individual geologies. The geometric effects of curved versus straight sections appear to not affect torque and drag. The results from the curved sections from the analyses have little relation to each other. As for more specific geometries, more analyses are needed before conclusions can be reached.Petroleum and Geosystems Engineerin
Changes In Femoral Neck Bone Mineral Density: A Comparison Of NHANES 2005-2006, 2007-2008, And 2009-2010
Bone mass is an important component of quality of life and can be influenced by lifestyle factors, such as physical activity and diet. However the US surgeon general found a growing portion of Americans are not engaging in adequate amounts of physical activity and/or consuming less calcium and vitamin D. The purpose of this study was to compare bone mineral density (BMD) of American adults of different ethnicities and time periods to detect any differences. It was hypothesized that BMD would be lower in participants from more recent years, and African Americans would have the highest BMD. Measurements were taken at the femoral neck of volunteers between 18 and 35 years of age (n = 3578) from 2005-2006 (n = 1160), 2007-2008, (n = 1135), and 2009-2010 (n = 1283) by the National Center for Health Statistics. The data was analyzed using a three-way independent ANOVA with an alpha level of .05. Femoral neck BMD was used as the dependent variable; and year, age, and race were independent variables. The study found Hispanic women to have a significantly higher BMD from 2005-2006 (p \u3c.05) when compared to participants from later years. In addition, the study found significant differences based on age and ethnicity (p \u3c .001). African-American men (p \u3c .001) and women (p \u3c.001) had a higher BMD than any other ethnicity. Moreover, Hispanic men had a higher BMD (p \u3c.001) than Caucasian men. In men, BMD significantly decreased in each age group (p \u3c.001); whereas in women a significant decrease was detected in every other age group (p \u3c .05). However, in contradiction to literature, the results found peak BMD to occur between 18 and 19 years of age as opposed to mid-to-late twenties
Full shell model calculation of the binding energies of the nuclei
Binding energies and other global properties of nuclei in the middle of the
shell, such as M1, E2 and Gamow-Teller sum rules, have been obtained using
a new Shell Model code (NATHAN) written in quasi-spin formalism and using a
-coupled basis. An extensive comparison is made with the recently
available Shell Model Monte Carlo results using the effective interaction KB3.
The binding energies for -nearly- all the nuclei are compared with
the measured (and extrapolated) results.Comment: 7 page
Associations between incident breast cancer and ambient concentrations of nitrogen dioxide from a national land use regression model in the Canadian National Breast Screening Study
Background: Air pollution has been classified as a human carcinogen based largely on epidemiological studies of lung cancer. Recent research suggests that exposure to ambient air pollution increases the risk of female breast cancer especially in premenopausal women. Methods: Our objective was to determine the association between residential exposure to ambient nitrogen dioxide (NO2) and newly diagnosed cases of invasive breast cancer in a cohort of 89,247 women enrolled in the Canadian National Breast Screening Study between 1980 and 1985.
Isolating the Roper Resonance in Lattice QCD
We present results for the first positive parity excited state of the
nucleon, namely, the Roper resonance (=1440 MeV) from a
variational analysis technique. The analysis is performed for pion masses as
low as 224 MeV in quenched QCD with the FLIC fermion action. A wide variety of
smeared-smeared correlation functions are used to construct correlation
matrices. This is done in order to find a suitable basis of operators for the
variational analysis such that eigenstates of the QCD Hamiltonian may be
isolated. A lower lying Roper state is observed that approaches the physical
Roper state.
To the best of our knowledge, the first time this state has been identified
at light quark masses using a variational approach.Comment: 7pp, 4 figures; minor typos corrected and one Ref. adde
A-dependence of nuclear transparency in quasielastic A(e,e'p) at high Q^2
The A-dependence of the quasielastic A(e,e'p) reaction has been studied at
SLAC with H-2, C, Fe, and Au nuclei at momentum transfers Q^2 = 1, 3, 5, and
6.8 (GeV/c)^2. We extract the nuclear transparency T(A,Q^2), a measure of the
average probability that the struck proton escapes from the nucleus A without
interaction. Several calculations predict a significant increase in T with
momentum transfer, a phenomenon known as Color Transparency. No significant
rise within errors is seen for any of the nuclei studied.Comment: 5 pages incl. 2 figures, Caltech preprint OAP-73
Shadowing in Inelastic Scattering of Muons on Carbon, Calcium and Lead at Low XBj
Nuclear shadowing is observed in the per-nucleon cross-sections of positive
muons on carbon, calcium and lead as compared to deuterium. The data were taken
by Fermilab experiment E665 using inelastically scattered muons of mean
incident momentum 470 GeV/c. Cross-section ratios are presented in the
kinematic region 0.0001 < XBj <0.56 and 0.1 < Q**2 < 80 GeVc. The data are
consistent with no significant nu or Q**2 dependence at fixed XBj. As XBj
decreases, the size of the shadowing effect, as well as its A dependence, are
found to approach the corresponding measurements in photoproduction.Comment: 22 pages, incl. 6 figures, to be published in Z. Phys.
The contribution of cattle urine and dung to nitrous oxide emissions: Quantification of country specific emission factors and implications for national inventories
Publication history: Accepted - 10 April 2018; Published online - 24 April 2018.Urine patches and dung pats from grazing livestock create hotspots for production and emission of the greenhouse
gas, nitrous oxide (N2O), and represent a large proportion of total N2O emissions in many national agricultural
greenhouse gas inventories. As such, there is much interest in developing country specific N2O emission
factors (EFs) for excretal nitrogen (EF3, pasture, range and paddock) deposited during gazing. The aims of this
study were to generate separate N2O emissions data for cattle derived urine and dung, to provide an evidence
base for the generation of a country specific EF for the UK from this nitrogen source. The experiments were
also designed to determine the effects of site and timing of application on emissions, and the efficacy of the nitrification
inhibitor, dicyandiamide (DCD) on N2O losses. This co-ordinated set of 15 plot-scale, year-long field experiments
using static chambers was conducted at five grassland sites, typical of the soil and climatic zones of
grazed grassland in the UK. We show that the average urine and dung N2O EFs were 0.69% and 0.19%, respectively,
resulting in a combined excretal N2O EF (EF3), of 0.49%, which is b25% of the IPCC default EF3 for excretal
returns from grazing cattle. Regression analysis suggests that urineN2O EFs were controlledmore by composition
than was the case for dung, whilst dung N2O EFs were more related to soil and environmental factors. The urine
N2O EF was significantly greater from the site in SW England, and significantly greater from the early grazing season urine application than later applications. Dycandiamide reduced the N2O EF fromurine patches by an average
of 46%. The significantly lower excretal EF3 than the IPCC default has implications for the UK's national inventory
and for subsequent carbon footprinting of UK ruminant livestock productsThe authors are grateful to the UK Department for Environment,
Food and Rural Affairs (Defra), the Department of Agriculture and Rural
Development (now the Department of Agriculture, Environment and
Rural Affairs) in Northern Ireland, and the Scottish Government and
the Welsh Government for financial support via the InveN2Ory project
(AC0116). The work by Rothamsted Research was additionally supported
by the Biotechnology and Biological Sciences Research Council
(BBS/E/C/000I0320). We would also like to thank Jon Moorby (IBERS,
Wales, UK), Reading University, SRUC (Scotland, UK) and Conrad Ferris
(AFBI, Northern Ireland, UK), for provision of cattle urine and dung
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