335 research outputs found
Validation of the use of SHARC Hydrocode to predict explosion effects in vented chambers
Computational Fluid Dynamics (CFD) models were created and analyzed using the commercially available hydrocode SHARC to determine if SHARC can accurately predict the behavior of explosions in enclosed vented chambers. Axisymmetric two-dimensional models were generated using the same physical parameters used in similar model tests performed by the US Army. Three different chamber/vent configurations were investigated with three charge sizes per configuration in order to compare the SHARC results to the data obtained from the model tests. The time of arrival of shocks and the peak over-pressure were compared. The calculations were then analyzed using several graphical tools currently available. It was found that SHARC is able to produce valid results, but with some limitations. One such limitation stems from the nature of computational fluid dynamics calculations in that some information is lost due to the discrete time steps used for calculating the various flow field parameters. Another limitation was introduced by the utility program necessary for restarting the code due to the interpolating process it uses to generate data for input to future executions of SHARC. As with any software used as an engineering aid, SHARC must be used with caution. Plots of flow parameters are recommended to analyze physical trends. Comparison plots are presented here for trend information only in the absence of highly expensive benchmark-quality data
History of education in Florida
History of Education in Florida authored by George Gary Bush and published by the Government Printing Office, Washington D.C. Contains prints of educational institutions in Florida. Contents for the book include: Florida Education Society, Early Legislation Affecting Primary Education, Taxation for the Support of Schools, New School Law, Time Needed to Devellp the New System, Statistics, Present Outlook, School Officers and their Duties, The Education of the Freedmen, Cookman Institute: A Normal and Biblical School for Colored Students, Teacher\u27s Institues, Nornal Schools, Academies and High Schools, Public School Lands, History of the Seminaries and Colleges, East Florida Seminary, West Florida Seminary, The State Agriculture College, Florida University, Rollins College, De Land University, The Florida Conference College, The St. John\u27s Conference College
Plato on Well-Being
Plato's dialogues use several terms for the concept of well-being, which concept plays a central ethical role as the ultimate goal for action and a central political role as the proper aim for states. But the dialogues also reveal sharp debate about what human well-being is. I argue that they endorse a Socratic conception of well-being as virtuous activity, by considering and rejecting several alternatives, including an ordinary conception that lists a variety of goods, a Protagorean conception that identifies one's well-being with what appears one to be one's well-being, and hedonistic conceptions
A novel analytical ultracentrifugation based approach to the low resolution structure of gum arabic
Under investigation are the structural properties of gum arabic, an industrially important biopolymer for use as a stabilizer or in drug delivery, using Analytical Ultracentrifugation—a well-established, matrix-free probe for macromolecular size and shape. These results are combined with chromatographically-coupled methods (multi-angle light scattering, differential press imbalance viscometry) to provide a global analysis of its structure in varying ionic strength conditions. This analysis indicates that gum Arabic may have a compact, elliptical structure in solution, the significance of which for biotechnological use is indicated. This modelling method can be applied to other biopolymers and synthetic polymers
Self-Reported Low Vitality, Poor Mental Health, and Low Dietary Restraint Are Associated with Overperception of Physical Exertion
Objective. We investigated whether perceived exertion, in comparison to the physiological response to exercise, was associated with self-reported vitality, mental health, and physical function during daily activities, or weight control behaviors.
Design. Weight-reduced, formerly overweight women (n = 126, aged 22–46 years), completed health and dietary control questionnaires, and underwent a treadmill-walking task while heart rate, ventilation, respiratory exchange ratio, and ratings of perceived exertion were recorded.
Results. Overperception of exertion (perceived exertion physiological exertion) was inversely associated with vitality (r = −0.190, P < .05), mental health (r = −0.188, P < .05), and dietary control (r values range −0.231 to −0.317, P < .05). In linear regression modeling, vitality or mental health, and cognitive dietary restraint were independently associated with accuracy of perceived exertion, independent of age, ethnicity, and engagement in exercise during weight loss. Each model explained 7%-8% of the variance in accuracy of perceived exertion.
Conclusion. Women with low vitality or poor mental health, and poor dietary control may overperceive exertion. Such overperception may be a barrier to engage in physical activity and thus increase susceptibility to weight gain
Vitamin D intake is associated with insulin sensitivity in African American, but not European American, women
<p>Abstract</p> <p>Background</p> <p>The prevalence of type 2 diabetes is higher among African Americans (AA) vs European Americans (EA), independent of obesity and other known confounders. Although the reason for this disparity is not known, it is possible that relatively low levels of vitamin D among AA may contribute, as vitamin D has been positively associated with insulin sensitivity in some studies. The objective of this study was to test the hypothesis that dietary vitamin D would be associated with a robust measure of insulin sensitivity in AA and EA women.</p> <p>Methods</p> <p>Subjects were 115 African American (AA) and 137 European American (EA) healthy, premenopausal women. Dietary intake was determined with 4-day food records; the insulin sensitivity index (S<sub>I</sub>) with a frequently-sampled intravenous glucose tolerance test and minimal modeling; the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) with fasting insulin and glucose; and body composition with dual-energy X-ray absorptiometry.</p> <p>Results</p> <p>Vitamin D intake was positively associated with S<sub>I </sub>(standardized β = 0.18, <it>P </it>= 0.05) and inversely associated with HOMA-IR (standardized β = -0.26, <it>P </it>= 0.007) in AA, and the relationships were independent of age, total body fat, energy intake, and % kcal from fat. Vitamin D intake was not significantly associated with indices of insulin sensitivity/resistance in EA (standardized β = 0.03, <it>P </it>= 0.74 and standardized β = 0.02, <it>P </it>= 0.85 for S<sub>I </sub>and HOMA-IR, respectively). Similar to vitamin D, dietary calcium was associated with S<sub>I </sub>and HOMA-IR among AA but not EA.</p> <p>Conclusions</p> <p>This study provides novel findings that dietary vitamin D and calcium were independently associated with insulin sensitivity in AA, but not EA. Promotion of these nutrients in the diet may reduce health disparities in type 2 diabetes risk among AA, although longitudinal and intervention studies are required.</p
Theology, News and Notes - Vol. 47, No. 01
Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1139/thumbnail.jp
Ferritin Levels in the Cerebrospinal Fluid Predict Alzheimer\u27s Disease Outcomes and Are Regulated by APOE
Brain iron elevation is implicated in Alzheimer\u27s disease (AD) pathogenesis, but the impact of iron on disease outcomes has not been previously explored in a longitudinal study. Ferritin is the major iron storage protein of the body; by using cerebrospinal fluid (CSF) levels of ferritin as an index, we explored whether brain iron status impacts longitudinal outcomes in the Alzheimer\u27s Disease Neuroimaging Initiative (ADNI) cohort. We show that baseline CSF ferritin levels were negatively associated with cognitive performance over 7 years in 91 cognitively normal, 144 mild cognitive impairment (MCI) and 67 AD subjects, and predicted MCI conversion to AD. Ferritin was strongly associated with CSF apolipoprotein E levels and was elevated by the Alzheimer\u27s risk allele, APOE-ɛ4. These findings reveal that elevated brain iron adversely impacts on AD progression, and introduce brain iron elevation as a possible mechanism for APOE-ɛ4 being the major genetic risk factor for AD
A Petal of the Sunflower: Photometry of the Stellar Tidal Stream in the Halo of Messier 63 (NGC 5055)
We present surface photometry of a very faint, giant arc feature in the halo
of the nearby spiral galaxy NGC 5055 (M63) that is consistent with being a part
of a stellar stream resulting from the disruption of a dwarf satellite galaxy.
This faint feature was first detected in early photographic studies by van der
Kruit (1979); more recently by Mart\'inez-Delgado et al. (2010) and as
presented in this work, the loop has been realized to be the result of a recent
minor merger through evidence obtained by deep images taken with a telescope of
only 0.16 m aperture. The stellar stream is confirmed in additional images
taken with the 0.5 m of the BlackBird Remote Observatory and the 0.8 m of the
McDonald Observatory. This low surface brightness structure around the disk of
the galaxy extends ~29 kpc from its center, with a projected width of 3.3 kpc.
The stream's morphology is consistent with that of the visible part of a
"great-circle" stellar stream originating from the accretion of a ~10^8 M_sun
dwarf satellite in the last few Gyr. The progenitor satellite's current
position and fate are not conclusive from our data. The color of the stream's
stars is consistent with Local Group dwarfs and is similar to the outer regions
of M63's disk and stellar halo. We detect other low surface brightness
"plumes"; some of these may be extended spiral features related to the galaxy's
complex spiral structure and others may be tidal debris associated with the
disruption of the galaxy's outer stellar disk as a result of the accretion
event. We differentiate between features related to the tidal stream and faint,
blue features in the outskirts of the galaxy's disk previously detected by the
GALEX satellite. With its highly warped HI gaseous disk (~20 deg), M63
represents one of several examples of an isolated spiral galaxy with a warped
disk showing strong evidence of an ongoing minor merger.Comment: 16 pages, 10 figures, 3 tables, Accepted for publication in The
Astronomical Journa
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