The radioactivity contributions of several daughter products of the 235,238 U and 232Th isotope decay chains within geological matrices can be assumed to be in equilibrium due to their age if they have remained undisturbed for an extended period of time. Similarly, one can assume that the isotopic mass proportions are equal to natural isotopic abundance. Current methods used to ascertain activity in these decay chains involve alpha particle spectrometry or ICP-MS, both of which can be laborious and time consuming. In this research, thermal and epithermal neutron activation analysis of small samples of various geological materials is used in order to ascertain activities. Through the use of NAA, cumbersome sample preparation and the need for large sample size and extended counting time are obviated. In addition to the decay chains of uranium and thorium, 40K, another large contributor to naturally occurring radioactivity, is determined using epithermal neutron activation analysis to determine total potassium content, and then calculating its isotopic contribution based on its natural isotopic abundance. / text

Spontaneous imbibition plays a very important role in the displacement mechanism of non-wetting fluid in naturally fractured reservoirs. We developed a new 2D two-phase finite element numerical model, as available commercial simulators cannot be used to model small-scale experiments with different boundary conditions as well as complex boundary conditions such as fractures and vugs. Starting with the basic equation of fluid flow, we derived the non-linear diffusion saturation equation. This equation cannot be put in weighted-integral weak variational form and hence Rayleigh-Ritz finite element method (FEM) cannot be applied. Traditionally, the way around it is to use higher order interpolation functions and use Galerkin FEM or reduce the differentiability requirement and use Mixed FEM formulation. Other FEM methods can also be used, but iterative nature of those methods makes them unsuitable for solving large-scale field problems. But if we truncate the non-linear terms and decouple the dependent variables, from the spatial as well as the temporal domains of the primary variable to solve them analytically, the non-linear FEM problem reduces to a simple weighted integral form, which can be put into its corresponding weak form. The advantage of using Rayleigh-Ritz method is that it has immediate effect on the computation time required to solve a particular problem apart from incorporating complex boundary conditions. We compared our numerical models with the analytical solution of this diffusion equation. We validated the FDM numerical model using X-Ray Tomography (CT) experimental data from the single-phase spontaneous imbibition experiment, where two simultaneously varying parameters of weight gain and CT water saturation were used and then went ahead and compared the results of FEM model to that of FDM model. A two-phase field size example was taken and results from a commercial simulator were compared to the FEM model to bring out the limitations of this approach.

No description available.

Two experiments were conducted to determine the effect of feeding diets with a 2009 and 2010 naturally-contaminated corn to weaning pigs. For both experiments three diets were blended to contain 100% 2010 naturally-contaminated corn (control), 50-50% blend of the 2009 naturally-contaminated corn and 2010 corn (Diet 2), and 100% 2009 naturally-contaminated corn (Diet 3). In Exp. 1, 24 crossbred pigs with an average body weight of 7.64 ± 0.70 kg were allotted to 4 replicates of 3 treatments with 2 pigs per pen, on the basis of gender, litter mate, and BW in a randomized complete block design. Fecal and urine samples were collected and dry matter, energy, and nitrogen apparent digestibility were determined. Dry matter, energy, and nitrogen digestibility were not affected by either Diet 3 or Diet 2 compared to the control diet. In Exp. 2, 30 crossbred pigs with an average body weight of 7.98 ± 1.15 kg were allotted to 3 replicates of 2 comparisons with 5 pigs per pen. Comparisons consisted of: 1) Control vs Diet 3, and 2) Control vs Diet 2. Two feeders were located in each pen containing one of the two diets. Feed preference and growth performance were determined. A preference for the feed containing 2010 corn feed was observed; pigs showed the ability to discriminate mycotoxin-contaminated feed (95.34 vs. 4.66%; P< 0.01). Nutrient digestibility was not affected by these diets, but a clear decrease in feed intake was observed in the pigs.

Chiral structure formation is ubiquitous in surface self-assembly. Molecules that do not undergo chiral recognition in solution or fluid phases can do so when their configurational freedom is restricted in the two-dimensional field of a substrate. The process holds promise in the manufacture of functional materials for chiral catalysis, sensing or nonlinear optics. In this thesis, we investigate the influence of surface attraction and geometry on adsorption-induced chiral separation in several model molecules, as well as the relationships between molecular features, specifically molecular geometry and charge distribution, and chiral recognition at surface self-assembly. Simple model molecules embody the fundamental interactions involved in supramolecular structure formation in experimental systems, and allow the in-depth investigation of key parameters. Chiral pattern formation at the surface self-assembly is a complex problem, even in cases where very small organic molecules are considered. Even though the adsorption behaviour of small organic molecules on gold surfaces has been investigated extensively so far experimentally and theoretically, much of their chiral behaviour is yet to be understood at a molecular level. Theoretical investigations of chiral self-assembly of sulfur containing amino acids onto achiral and chiral gold surfaces is also presented in this thesis. By understanding chiral self-assembly on solid surfaces, one may control and direct it towards creating materials with desired functionality. / Graduate / 0494 / tp.popa@gmail.com

Thesis (M.Arch.)--University of Detroit Mercy, 2009. / "April 24th, 2009." Includes bibliographical references (p. 118).

Thesis (M.S.)--Minot State University, 2005. / Includes bibliographical references (leaves 40-42).

Master of Science / Department of Animal Sciences and Industry / Terry Houser / Two studies were conducted to determine the effectiveness of naturally smoked sugar in a conventional and natural curing brines to inhibit lipid oxidation in frozen, aerobically packaged, layout style bacon. Commercial pork bellies were trimmed and cut in half creating anterior and posterior sections. Each section was randomly assigned to one of two treatments targeted 12% injection: control brine or a brine containing naturally smoked sugar (n =15/treatment). In the first study a conventional control brine consisted of 76.4% water, 11.8% salt, 8.00% sugar, 1.70% sodium phosphate, 1.60% sodium nitrite, and 0.450% sodium erythorbate. The treatment brine contained the same ingredients with the addition of 5.00% naturally smoked sugar. In the second study a natural control curing brine was utilized and contained 72.0% water, 13.4% sea salt, 8.00% cane sugar, and 6.67% celery juice. While treatment brine had the same ingredients as the natural control brine with the addition 5.00% smoked sugar. Bacon slices were randomly assigned to four sensory and GCMS frozen storage periods (0, 40, 80, and 120 day) or seven thiobarbituric acid reactive substances (TBARS) frozen storage times (0, 20, 40, 60, 80, 100, and 120 day). To measure lipid oxidation trained sensory evaluation, TBARS, and gas chromatography mass spectrometry (GCMS) was conducted after the assigned frozen storage periods. All bacon slices were stored aerobically at -18 ± 2 °C for their designated storage period. The first study panelist scores for oxidized flavor of the conventional control bacon increased from day 0 to 120; whereas the naturally smoked sugar treatment had decreased panelist scores (P > 0.16) for oxidized flavor intensity compared to the control bacon. Also, TBARS results values for the conventional control bacon increased (P < 0.01) from day 20 to day 120; while the conventional naturally smoked sugar treatment remained constant (P > 0.99). Hexanal content for conventional control increased (P < 0.003) during frozen storage; but naturally smoked sugar TBARS values were not different from day 0 of storage (P > 0.734). Concentration of heptanal in conventional control bacon was the highest (P < 0.003) at day 80 and 120 of frozen storage. Heptanal content in conventional bacon with naturally smoked sugar was not different from day 0 of frozen storage (P > 0.846). Conventional bacon formulated with naturally smoked sugar had greater concentrations of creosol and syringol than control bacon (P < 0.003). In the second study, naturally cured bacon had increased panelist scores for oxidized flavor from day 0 to 120 of frozen storage (P < 0.001). Natural bacon with smoked sugar had oxidized flavor scores that remained constant during frozen storage (P > 0.936). Naturally cured bacon displayed increased TBARS values from day 20 to 120 of frozen storage (P < 0.001). Naturally cured bacon with smoked sugar exhibited static TBARS values throughout the frozen storage period (P > 0.196). Thus, smoked sugar is an effective antioxidant in frozen sliced, aerobically packaged, conventionally cured and naturally cured bacon.

Methods of collecting, concentrating, separating, and identifying organic compounds in natural water systems are presented. These methods were applied to a eutrophic reservoir (Hyrum Reservoir, Utah) and resulted in the identification of the following 27 volatile, organic compounds: Alcohols: methanol, ethanol, 1-propanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-methyl-l-butanol, methyl-1- butanol, 3-methyl-2-butanol, 2-methyl-2-butanol, 2-methyl-3-buten-2-ol, 1-penten-3-ol, 2-methyl-2-pentanol Ketones: acetone, methyl ethyl ketone, 4-methyl-3-penten-2-one Aldehydes: acetaldehyde, propanal, 2-buten-1-al Others: acetonitrile, ethyl acetate, pyridine, 3-methylpyridine, diethyl ether The concentration level of the following 13 compounds was established in the reservoir from October 1974 to January 1976: Alcohols: methanol, ethanol, propanol, isopropyl alcohol, 1-butanol, isobutyl alcohol, tert-butyl alcohol 2-methyl-2-butanol, 2-methyl-3-buten-2-ol Ketones: acetone, methyl ethyl ketone Others: acetonitrile, acetaldehyde The highest concentrations of organics were found in the late summer or early fall as the bloom of Aphanizomenon flos-aquae died and the level of bacterial fermentation increased. Other sources of organic compounds in the reservoir (besides fermentation) included compounds (acetonitrile and ethanol) at least partially produced by active algal growth and associated bacteria. Melting snowpack and mountain streams that feed the reservoir also contained organic compounds similar to those found in the reservoir, however at lower levels. Most of the compounds at low concentrations had no effect on the growth of certain algae tested, however there was some indication that certain organics may have increased the net growth of Aphanizomenon flos-aquae.

A set of equations describing the motion of a naturally curved and twisted slender elastic rod is determined in this thesis. In particular, a study of the vibration of a helical spring is made, and the natural frequencies from the theory presented are compared with those from a simpler theory. Comparison of the two theories shows that the simpler theory is valid for most springs. The simpler theory is then used to show how the natural frequencies for a helical spring can be obtained when the spring is subjected to any boundary conditions. Finally, an analytical and experimental study of the vibration of a helical spring clamped at both ends is made in order to investigate the validity of the theory presented. / Thesis / Master of Engineering (MEngr)