This study estimated soybean yield responses to K fertilizer using trials data from 18 sites in Mississippi from 2011-2016. Eight response functions were fitted, including linear, linear plateau, quadratic, quadratic-plateau, square root quadratic, spherical plateau, exponential, and exponential-plateau functions. The ratio of high responsive, low responsive, and no responsive sites to K rates is 3:3:12 respectively. The response functions led to different predicted optimal K rates, and the best response function for each site was determined by the Vuong closeness test and economic loss analysis. The predicted economically optimal K rates are 157, 73, and 0 lb/acre for high, low, and no response sites respectively, and the average optimal K rate is 55 lb/acre. Compared to the currently used regional uniform K fertilizer rate of 80 lb/acre, the response-based K rates are expected to generate soybean production gain of about $14 per acre for Mississippi soybean producers.

The oxidation of Pd single crystals: Pd(111), Pd(100) and Pd(110) was studied using Temperature Programmed Desorption (TPD), X-ray Photoelectron Spectroscopy (XPS), Auger Electron Spectroscopy (AES), Low Electron Energy Diffraction (LEED) and Scanning Tunneling Microscopy (STM) as they were subjected to O2 in the pressure range between 1 and 150 Torr at temperatures 600-900 K. The oxygen species formed during oxidation, the oxygen uptake dependence on the sample history, the Pd single crystal surface morphology transformations, and the catalytic methane combustion over Pd single crystals were investigated in detail. The Pd single crystal oxidation proceeded through a three-step mechanism. Namely, (1) oxygen dissociatively adsorbed on Pd surface, forming chemisorbed oxygen and then surface oxide; (2) atomic oxygen diffused through a thin surface oxide layer into Pd metal, forming near surface and bulk oxygen; (3) bulk PdO formed when a critical oxygen concentration was reached in the near surface region. The diffusion of oxygen through thin surface oxide layer into Pd metal decreased in the order: Pd(110)>Pd(100)>Pd(111). The oxygen diffusion coefficient was estimated to be around 10-16 cm2 s-1 at 600 K, with an activation energy of 80 kJ mol-1. Once bulk PdO was formed, the diffusion of oxygen through the bulk oxide layer was the rate-determining step for the palladium oxidation. The diffusion coefficient was equal to 10-18 cm2 s-1 at 600 K and the activation energy was approximately 120 kJ mol-1. The oxygen diffusion through thin surface oxide layer and bulk PdO followed the Mott-Cabrera parabolic diffusion law. The oxygen uptake on Pd single crystals depended on the sample history. The uptake amount increased with the population of the bulk oxygen species, which was achieved by high oxygen exposure at elevated temperatures, for example in 1 Torr O2 at above 820 K. Ar+ sputtering or annealing in vacuum at 1300 K depleted the bulk oxygen. The Pd single crystal surface morphology was determined by the oxidation conditions: O2 pressure, treatment temperature and exposure time. When bulk PdO was formed, the single crystal surface was covered with semi-spherical agglomerates 2-4 nm in size, which tended to aggregate to form a“cauliflower-like" superstructure. The single crystal surface area during oxidation, determined by integrating the STM image, experienced three major expansions in consistent with a three-step oxidation mechanism. The surface area on the oxidized single crystals increased in the order: Pd(110)

The aim of this study is to form a theoretical model for simulation of glass forming ability of Fe &amp / #65533 / Based bulk amorphous alloys, to synthesize Fe &amp / #65533 / based multicomponent glassy alloys by using the predictions of the theoretical study, and to analyze the influence of crystallization and solidification kinetics on the microstructural features of this amorphous alloys. For this purpose, first, glass forming ability of Fe &amp / #65533 / (Mo, B, Cr, Nb, C) &amp / #65533 / X ( X = various alloying elements, selected from the periodic table) ternary alloy systems were simulated for twenty different alloy compositions by using the electronic theory of alloys in pseudopotential approximation and regular solution theory. Then, by using the results of the theoretical study, systematic casting experiments were performed by using centrifugal casting method. The alloying elements were melted with induction under argon atmosphere in alumina crucibles and casted into copper molds of different shapes. Characterization of the cast specimens were performed by using DSC, XRD, SEM, and optical microscopy. Comparison of equilibrium and nonequilibrium solidification structures of cast specimens were also performed so as to verify the existence of the amorphous phase. Good agreement of the results of experimental work, with the predictions of the theoretical study, and the related literature was obtained.