Evaluation of Ankom F58 Filter Bags Compared to Dacron Bags and Beakers for Analysis of Acid Detergent Fiber

Feed and fecal samples were analyzed to compare three methods of determining acid detergent fiber. Each sample was weighed into both Dacron and Ankom F58 fiber bags and then analyzed using an Ankom fiber analyzer. Results were then compared to the Van Soest beaker method. Ankom F58 bags helped reduce washout of small particles associated with Dacron bags, but fecal samples needed to be incubated in detergent for an extended amount of time to isolate acid detergent fiber material. Utilizing a technique that produces correct acid detergent fiber values is important for producers because these values are used as a proxy for calculating total digestible nutrients of feedstuffs

Constraining cosmological ultra-large scale structure using numerical relativity

Cosmic inflation, a period of accelerated expansion in the early universe, can give rise to large amplitude ultra-large scale inhomogeneities on distance scales comparable to or larger than the observable universe. The cosmic microwave background (CMB) anisotropy on the largest angular scales is sensitive to such inhomogeneities and can be used to constrain the presence of ultra-large scale structure (ULSS). We numerically evolve nonlinear inhomogeneities present at the beginning of inflation in full General Relativity to assess the CMB quadrupole constraint on the amplitude of the initial fluctuations and the size of the observable universe relative to a length scale characterizing the ULSS. To obtain a statistically significant number of simulations, we adopt a toy model in which inhomogeneities are injected along a preferred direction. We compute the likelihood function for the CMB quadrupole including both ULSS and the standard quantum fluctuations produced during inflation. We compute the posterior given the observed CMB quadrupole, finding that when including gravitational nonlinearities, ULSS curvature perturbations of order unity are allowed by the data, even on length scales not too much larger than the size of the observable universe. Our results illustrate the utility and importance of numerical relativity for constraining early universe cosmology.Comment: 14 pages, 6 figures v3: Clarifications added regarding the generality of results - conclusions unchanged, version accepted for publication in PRD, v2: updated with minor clarifications, submitte

Improvements in physics "Advanced Laboratory Courses"

Issued as Final project report, Project no. G-41-53

Evaluation of Protein Utilization in Low and High Protein Forage Sources and the Economic Value of Supplementing Field Peas (pisum sativum) to Growing Cattle Grazing Crested Wheatgrass Pastures

Field peas are widely grown in the panhandle of Nebraska; however, markets quickly become saturated. A two year experiment was conducted comparing field peas to dry distillers grains with solubles (DDGS) as a protein supplement. The objective was to establish a price producers could pay for field peas relative to DDGS. There was a significant difference in ADG due to type of supplement (P = 0.02). Field pea supplemented heifers had 10% lower ADG compared to DDGS supplemented heifers. Economically, this means if DDGS is priced at or $124.58/ 909 kg DM a producer could pay$2.89/ 27 kg, for field peas. Variable sources of grazed forages are used in cattle backgrounding systems, but in most systems metabolizable protein (MP) is limiting and rumen undegradable protein (RUP) supplement can meet this deficiency. The first objective was to determine if RUP is limiting and the second objective was to determine if highly digestible forages with rapid passage rate allow some rumen degradable protein (RDP) to bypass the rumen. A pooled analysis of growing cattle grazing forages demonstrated that average daily gain (ADG) increased with increased RUP supplement received, with the exception of animals grazing forages that were 17% crude protein (CP) or greater. A metabolism study evaluating high and low quality forages showed lower intakes and digestibility values for the lower quality forages. Rapid liquid passage rates suggest some degradable protein could be leaving the rumen before degradation. Numerous digestibility markers were used to evaluate markers in forage based diets. Advisor: Andrea K. Watso

On Charge-3 Cyclic Monopoles

We determine the spectral curve of charge 3 BPS su(2) monopoles with C_3 cyclic symmetry. The symmetry means that the genus 4 spectral curve covers a (Toda) spectral curve of genus 2. A well adapted homology basis is presented enabling the theta functions and monopole data of the genus 4 curve to be given in terms of genus 2 data. The Richelot correspondence, a generalization of the arithmetic mean, is used to solve for this genus 2 curve. Results of other approaches are compared.Comment: 34 pages, 16 figures. Revision: Abstract added and a few small change

Dispersion of the high-energy phonon modes in Nd1.85_{1.85}Ce0.15_{0.15}CuO4_4

The dispersion of the high-energy phonon modes in the electron doped high-temperature superconductor Nd$_{1.85}$Ce$_{0.15}$CuO$_4$ has been studied by inelastic neutron scattering. The frequencies of phonon modes with Cu-O bond-stretching character drop abruptly when going from the Brillouin zone center along the [100]-direction; this dispersion is qualitatively similar to observations in the hole-doped cuprates. We also find a softening of the bond-stretching modes along the [110]-direction but which is weaker and exhibits a sinusoidal dispersion. The phonon anomalies are discussed in comparison to hole-doped cuprate superconductors and other metallic perovskites

Origin and roles of a strong electron-phonon interaction in cuprate oxide superconductors

A strong electron-phonon interaction arises from the modulation of the superexchange interaction by phonons. As is studied in Phys. Rev. B 70, 184514 (2004), Cu-O bond stretching modes can be soft around (pm pi/a, 0) and (0, pm pi/a), with a the lattice constant of CuO_2 planes. In the critical region of SDW, where antiferromagnetic spin fluctuations are developed around nesting wave numbers Q of the Fermi surface, the stretching modes can also be soft around 2Q. Almost symmetric energy dependences of the 2Q component of the density of states, which are observed in the so called stripe and checker-board states, cannot be explained by CDW with 2Q following the complete softening of the 2Q modes, but they can be explained by a second-harmonic effect of SDW with Q. The strong electron-phonon interaction can play no or only a minor role in the occurrence of superconductivity.Comment: 5 pages, 1 fugur

Comparison blocks

"File: Human Relations, 3/79/5M""Playing with blocks is extremely important activity in the life of a preschool child. It is considered by educators to be one of the most important activities in which preschoolers can engage."--First paragraph.Ginny Braden (Area Child and Family Development Specialist), Marilyn C. Blossom (Child and Family Development Department Chairman