Decay of far flow field in trailing vortices

A finite difference machine code is used in the wake vortex problems in the quasi-cylindrical boundary layer approximation. A turbulent energy model containing new features is developed that accounts for the major effects disclosed by more advanced models in which the parameters are not yet established. Several puzzles that arose in previous theoretical investigations of wake vortices are resolved

A Pannenbergian proposal for doing religious epistemology in the light of its contemporary development in the thought of Kant, Hegel, and Kierkegaard

https://place.asburyseminary.edu/ecommonsatsdissertations/2197/thumbnail.jp

A site-specific standard for comparing dynamic solar ultraviolet protection characteristics of established tree canopies

A standardised procedure for making fair and comparable assessments of the ultraviolet protection of an established tree canopy that takes into account canopy movement and the changing position of the sun is presented for use by government, planning, and environmental health authorities. The technique utilises video image capture and replaces the need for measurement by ultraviolet radiometers for surveying shade quality characteristics of trees growing in public parks, playgrounds and urban settings. The technique improves upon tree shade assessments that may be based upon single measurements of the ultraviolet irradiance observed from a fixed point of view. The presented technique demonstrates how intelligent shade audits can be conducted without the need for specialist equipment, enabling the calculation of the Shade Protection Index (SPI) and Ultraviolet Protection Factor (UPF) for any discreet time interval and over a full calendar year

Dual-Energy X-Ray Absorptiometry for Determination of Body Composition in a Porcine Model of Obesity Development

To determine the efficacy of bioactive molecules for minimizing body fat accretion in mammals, an effective method for measuring changes in body fat must be used. In the current study, the precision and accuracy of the Dual Energy X-ray Absorptiometry (DEXA) estimates of the weight and tissue (fat, lean and bone mineral) content of two body depots (carcass and internal organs) were evaluated in heavy weight pigs (133-265 kg) serving as an obesity development model. DEXA accurately estimated carcass weight, but underestimated the fat tissue contents and overestimated the lean tissue contents of both the carcass and organ depots relative to those estimated from chemical analysis of the fat and protein contents of the depots. However, DEXA precisely detected changes in carcass and organ depot weights (R2 = .99, .99 respectively) and less precisely detected changes in the depot’s chemically determined fat (R2 = .95, .73) and protein content (R2 = .88, .84). Specifically, for each 1 kg change in carcass and organ depot weights, DEXA predicted the changes with a 95 % confidence (2 SE of estimate) within ± .008 and .026 kg, respectively. For each 1 kg change in the two depot’s chemically determined fat content, DEXA predicted the change within ± .092 and .338 kg, respectively. In conclusion, DEXA is a method that can precisely detect changes in body composition in large, heavy weight pigs being used in a model of obesity development.

Efficacy of Pantothenic Acid as a Modifier of Body Composition in a Porcine Model of Obesity Development

Our group’s previous research has shown that pantothenic acid (PA) fed in amounts above that needed to maximize body growth effectively reduce fat tissue accretion in pigs. In the current study, the efficacy of PA to minimize fatty tissue accretion in a porcine model of obesity development was determined. Heavy weight pigs (156 kg) were allotted to one of four dietary regimens consisting of a basal diet (8 ppm PA) supplemented with 0, 80, 800, 8000 ppm added PA. The basal diet contained a dietary nutrient mix representative of the American diet (34 % of calories from fat) at daily caloric intakes equivalent to 1.8 times the animal’s maintenance needs for 144 days. A state of obesity development occurred over the duration of the study. Specifically, pigs accrued 73 kg of body weight, of which 48 % was fat tissue. Whole body fat tissue content responded quadratically to increasing PA additions. Body fat percentage was reduced by .9 percentage units by the 80 ppm added PA and increased by 1.6 and 1.1 percentage units by the 800 and 8000 ppm added PA. Based on these data, PA is not an efficient modifier of body composition in a porcine model of obesity development induced by a high fat dietary regimen

On the size of the Fe II emitting region in the AGN Akn 120

We present a reverberation analysis of the strong, variable optical Fe II emission bands in the spectrum of Akn 120, a low-redshift AGN which is one of the best candidates for such a study. On time scales of several years the Fe II line strengths follow the variations in the continuum strength. However, we are unable to measure a clear reverberation lag time for these Fe II lines on any time scale. This is due to the very broad and flat-topped nature of the Fe II cross correlation functions, as compared to the H-beta response which is much more sharply localized in time. Although there is some suggestion in the light curve of a 300-day response time, our statistical analysis does not pick up such a feature. We conclude that the optical Fe II emission does not come from a photoionization-powered region similar in size to the H-beta emitting region, but we cannot say for sure where it does come from. Our results are generally consistent either with emission from a photoionized region several times larger than the H-beta zone, or with emission from gas heated by some other means, perhaps responding only indirectly to the continuum variations.Comment: Accepted for publication in the Ap

Deriving bases for Abelian functions

We present a new method to explicitly define Abelian functions associated with algebraic curves, for the purpose of finding bases for the relevant vector spaces of such functions. We demonstrate the procedure with the functions associated with a trigonal curve of genus four. The main motivation for the construction of such bases is that it allows systematic methods for the derivation of the addition formulae and differential equations satisfied by the functions. We present a new 3-term 2-variable addition formulae and a complete set of differential equations to generalise the classic Weierstrass identities for the case of the trigonal curve of genus four.Comment: 35page

Experimental study of optimal measurements for quantum state tomography

Quantum tomography is a critically important tool to evaluate quantum hardware, making it essential to develop optimized measurement strategies that are both accurate and efficient. We compare a variety of strategies using nearly pure test states. Those that are informationally complete for all states are found to be accurate and reliable even in the presence of errors in the measurements themselves, while those designed to be complete only for pure states are far more efficient but highly sensitive to such errors. Our results highlight the unavoidable tradeoffs inherent to quantum tomography.Comment: 5 pages, 3 figure

Short-Timescale monitoring of the X-ray, UV and broad double-peak emission line of the nucleus of NGC 1097

Recent studies have suggested that the short-timescale ($\lesssim7$ days) variability of the broad ($\sim$10,000 km s$^{-1}$) double-peaked H$\alpha$ profile of the LINER nucleus of NGC1097 could be driven by a variable X-ray emission from a central radiatively inefficient accretion flow (RIAF). To test this scenario, we have monitored the NGC1097 nucleus in X-ray and UV continuum with Swift and the H$\alpha$ flux and profile in the optical spectrum using SOAR and Gemini-South from 2012 August to 2013 February. During the monitoring campaign, the H$\alpha$ flux remained at a very low level --- 3 times lower than the maximum flux observed in previous campaigns and showing only limited ($\sim 20\%$) variability. The X-ray variations were small, only $\sim 13\%$ throughout the campaign, while the UV did not show significant variations. We concluded that the timescale of the H$\alpha$ profile variation is close to the sampling interval of the optical observations, which results in only marginal correlation between the X-ray and H$\alpha$ fluxes. We have caught the AGN in NGC1097 in a very low activity state, in which the ionizing source was very weak and capable of ionizing just the innermost part of the gas in the disk. Nonetheless, the data presented here still support the picture in which the gas that emits the broad double-peaked Balmer lines is illuminated/ionized by a source of high-energy photons which is located interior to the inner radius of the line-emitting part of the disk.Comment: The paper contains 14 pages, 7 figures and is accepted for publication at the Astrophysical Journa