Verification and Validation Studies for the KATS Aerothermodynamics and Material Response Solver

Modeling the atmospheric entry of spacecraft is challenging because of the large number of physical phenomena that occur during the process. In order to study thermal protection systems, engineers rely on high fidelity solvers to provide accurate predictions of both the thermochemical environment surrounding the heat shield, and its material response. Therefore, it is necessary to guarantee that the numerical models are correctly implemented and thoroughly validated. In recent years, a high-fidelity modeling tool has been developed at the University of Kentucky for the purpose of studying atmospheric entry. The objective of this work is to verify and validate this code. The verification consists of the development of an automated regression testing utility. It is intended to both aid code developers in the debugging process, as well as verify the correct implementation of the numerical models as these are developed. The validation process will be performed through comparison to relevant ablation experiments, namely arc-jet tests. Two modules of the code are used: fluid dynamics, and material response. First the fluid dynamics module is verified against both computational and experimental data on two distinct arc-jet tests. The material response module is then validated against arc-jet test data using PICA

Comparison of Trace Mineral Repletion Strategies in Beef Cattle to Overcome a High Antagonist Diet

It was observed that diets with high sulfur and molybdenum decreased markers of copper, selenium, and manganese after 90 d. In a 62-d trace mineral repletion period, steers receiving an injection of Multimin90 had the most rapid improvement of copper and selenium status by d 14, while it took 28 d and 42 d for copper and selenium status to improve in steers supplemented with 150% of national recommended concentrations from either an inorganic and organic blend, or only inorganic trace minerals. Further research is needed to understand the optimal trace mineral supplementation strategy to overcome dietary antagonisms without creating economic loss for producers

The Influence of Supplemental Zinc and Ractopamine Hydrochloride on Mineral and Nitrogen Retention of Beef Steers

The objective of this study was to ascertain how ractopamine hydrochloride supplementation and Zn supplementation affects N retention and Zn absorption in beef steers. No interaction was detected between ractopamine hydrochloride supplementation and Zn supplementation (MIN x BA strategies). There was no effect of ractopamine hydrochloride inclusion on Zn absorption. However, there was an increase of Zn retention with increasing concentrations of supplemental Zn. Additionally, N retention was increased by supranutritional Zn supplementation and also by ractopamine supplementation. Increased N retention may help explain previously noted improvements in cattle performance when fed ractopamine hydrochloride and supranutritional concentrations of Zn

Reproductive Justice

https://digitalcommons.chapman.edu/feminist_zines/1057/thumbnail.jp

Effect of Varying Trace Mineral Supplementation of Steers with or without Hormone Implants on Growth and Carcass Characteristics

The utilization of hormone implants and the supplementation of trace minerals have become well adopted management strategies in the feedlot industry. When hormone implants increase rates of growth in feedlot cattle, this could increase the demand for trace minerals to support those rapid rates of growth. In this study, an aggressive implant strategy dramatically increased growth rates and HCW, without having negative effects on marbling score. It was also observed, regardless of hormone implant, trace mineral supplementation tended to increase overall ADG and steers supplemented at industry consultants recommended concentrations had a 33 lb increase in HCW compared to cattle that received no trace mineral supplementation. This would suggest that hormone implants remain a good return on investment and the current national trace mineral recommendations may not be adequate to support the optimum growth finishing beef steers

Effects of Original XPC on Newly Weaned Beef Steer Nutrient Digestibility and Response to a Vaccination Challenge

The study was designed to determine the effects of Diamond V Original XPC, a yeast fermentation product, in the diets of newly weaned beef steers on nutrient digestibility and response to a vaccination challenge. Although no overall performance benefit was noted, XPC improved total tract CP digestibility. Steers fed XPC at 14 g/d exhibited lesser concentrations of APP, greater DMI, and more efficient rumination post-vaccination. Further research is needed to determine the optimal supplementation rate of XPC to newly received beef cattle

Effects of Original XPC on Newly Weaned Beef Steer Growth Performance and Antioxidant Defense

The objective of this study was to determine the effects of increasing inclusions of Diamond V Original XPC, a yeast fermentation product, on newly weaned beef steer performance and antioxidant defense. There was no effect of Original XPC on growth performance in the current study; however, blood measures indicated greater antioxidant capacity and lesser oxidative stress for steers fed XPC at 14 g/d. Further research is needed to better understand how oxidative stress impacts animal performance and health as well as the optimum supplementation dose of XPC for newly received beef cattle

Development of a Three-Dimensional, Unstructured Material Response Design Tool

A preliminary verification and validation of a new material response model is presented. This model, Icarus, is intended to serve as a design tool for the thermal protection systems of re-entry vehicles. Currently, the capability of the model is limited to simulating the pyrolysis of a material as a result of the radiative and convective surface heating imposed on the material from the surrounding high enthalpy gas. Since the major focus behind the development of Icarus has been model extensibility, the hope is that additional physics can be quickly added. This extensibility is critical since thermal protection systems are becoming increasing complex, e.g. woven carbon polymers. Additionally, as a three-dimensional, unstructured, finite-volume model, Icarus is capable of modeling complex geometries. In this paper, the mathematical and numerical formulation is presented followed by a discussion of the software architecture and some preliminary verification and validation studies