Fertilizer effects on soil pH, soil nutrients, and nutrient uptake in swamp white and pin oak seedlings on an alkaline Missouri River bottomland

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Title from PDF of title page (University of Missouri--Columbia, viewed on September 25, 2009).Thesis advisors: Dr. John Dwyer, Dr. Felix Ponder, Jr.M.S. University of Missouri--Columbia 2008.There is growing interest among forest and wildlife managers in the reforestation of bottomlands with mast producing hardwoods in the Lower Missouri River and Mississippi River Alluvial valleys. However, it is common for bottomland hardwood plantings to experience high failure rates due to reasons such as improper soil pH, low nutrient availability, and poor drainage. In this study, fertilizer treatments containing combinations of S, Fe, and N were applied to pin and swamp white oak seedlings planted in a bedded and non-bedded calcareous (pH 8.29) soil in a Missouri River bottomland. Objectives were to evaluate the effects of these fertilizers on seedling foliar nutrient content, soil pH, and soil nutrient concentration at two depths throughout the growing season. The availability of nine nutrients was improved, mainly due to reductions in pH with the application of S, but many of the essential nutrient elements remain below sufficiency levels in the seedling foliage. The sandy soil at the Plowboy Bend Conservation Area study site did not benefit significantly from soil bedding. Overall, the growth of the trees at Plowboy Bend Conservation Area could not be accurately measured because of the greater herbivory by rabbits and white-tail deer on trees in some fertilizer treatments compared to others.Includes bibliographical references

Order-disorder transformations in Sm–Co and Sm–Co–ZrC systems with 2-17 stoichiometry

This work investigates the order-disorder transformations utilizing time-resolved x-ray diffraction at the Advanced Photon Source. The metastable phases that can form during the order-disorder transformations in the Sm–Co intermetallics have the potential to produce materials with enhanced permanent magnetic properties. The high-temperature experiments transformed the disordered alloys with the TbCu7-type structure obtained by rapid solidification into the mixture of the hexagonal and rhombohedral ordered structures at 1375 K. The ordering process and the role of the ZrC alloying on the phase formation and ordering transformations were examined. The results showed the formation of shoulders of the fundamental peaks and superlattice peak broadening prior to complete ordering. The lattice parameters expanded linearly up to the onset of ordering, after which an abrupt change of slope was observed. The change in slope suggests a nucleation and growth mechanism for the ordering transformation. The effect of ZrC alloying promoted the formation of the disordered structure in the as-solidified state and lowered the onset of the ordering temperature

ESTIMATING THE SUBJECT BY TREATMENT INTERACTION IN NON-REPLICATED CROSSOVER DIET STUDIES

Researchers in human nutrition commonly refer to the ‘consistent’ diet effect (i.e. the main effect of diet) and an ‘inconsistent’ diet effect (i.e. a subject by diet interaction). However, due to the non-replicated designs of most studies, one can only estimate the first part using ANOVA; the latter (interaction) is confounded with the residual noise. In many diet studies, it appears that subjects do respond differently to the same diet, so the subject by diet interaction may be large. In a search of over 40,000 published human nutrition studies, most using a crossover design, we found that in none was a subject by diet interaction effect estimated. For this paper, we examined LDL-cholesterol data from a non-replicated crossover study with four diets, the typical American diet, with and without added plant sterols, and a cholesterol-lowering Step-1 diet, with and without sterols. We also examined LDL-cholesterol data from a second crossover study with some replications with three diets, representing the daily supplement of 0, 1 or 2 servings of pistachio nuts. These two data sets were chosen because experience suggested that LDLcholesterol responses to diet tend to be subject-specific. The second data set, with some replication, allowed us to estimate the subject by diet interaction term in a traditional ANOVA framework. One approach to estimating an interaction effect in non-replicated studies is through the use of a multiplicative decomposition of the interaction (sometimes called AMMI―additive main effects, multiplicative interaction). In this type of analysis, residuals, formed after estimated main effects are subtracted from the data, are arrayed in a matrix with diets as columns and subjects as rows. A singular value decomposition of the matrix is performed and the first, or first and second, principal component(s) are used as estimates of the interaction, and can be tested for significance using approximate F-tests. Using the R gnm package, we found large and significant subject by diet interaction effects in both data sets; estimates of the interaction in the second data set were similar to interaction estimates from traditional ANOVA. Of an additional 26 dependent variables from the first and a third data set (the latter investigating the effect of mild alcohol consumption on blood variables), 19 had significant subject by diet interactions, based on the AMMI methodology. These results suggest that the subject by diet interaction is often important and should not be ignored when analyzing data obtained from non-replicated crossover designs―the AMMI methodology works well and is readily available in statistical software packages

Simulation of alnico coercivity

Micromagnetic simulations of alnico show substantial deviations from Stoner-Wohlfarth behavior due to the unique size and spatial distribution of the rod-like Fe-Co phase formed during spinodal decomposition in an external magnetic field. The maximum coercivity is limited by single-rod effects, especially deviations from ellipsoidal shape, and by interactions between the rods. Both the exchange interaction between connected rods and magnetostatic interaction between rods are considered, and the results of our calculations show good agreement with recent experiments. Unlike systems dominated by magnetocrystalline anisotropy, coercivity in alnico is highly dependent on size, shape, and geometric distribution of the Fe-Co phase, all factors that can be tuned with appropriate chemistry and thermal-magnetic annealing