Simplicial Chiral Models

Principal chiral models on a d-1 dimensional simplex are introduced and studied analytically in the large $N$ limit. The $d = 0, 2, 4$ and $\infty$ models are explicitly solved. Relationship with standard lattice models and with few-matrix systems in the double scaling limit are discussed.Comment: 6 pages, PHYZZ

The influence of sires used in artificial insemination on dairy cattle production traits in upper East Tennessee dairy herds

The genetic Improvement of production traits in the dairy herds necessitates the use of breeding animals that are genetically superior to the average of the population. Since approximately 60 per cent of the dairy heifers born are required for normal herd replacements, genetic improvement is largely produced by the extensive use of out-standing dairy sires through artificial insemination programs. Artificial insemination (A.I.) provides an opportunity for the selection and extensive use of dairy sires that have demonstrated their genetic superiority. The extensive use possible via artificial insemi-nation is illustrated by the following figures: In 1962 (13) the average number of first services was 3155 per sire in A. I. The average number of first services varied from 1322 to 4629 per sire for organi-zations inseminating less than 100,000 cows and over 200,000 cows, respectively. The East Tennessee Artificial Breeding Association reported 25,164 first services to dairy sires with an average of 922 per dairy sire for 1963. The acceptance of artificial insemination of dairy cows has increased in the East Tennessee area in recent years. In 1963, it was estimated that over 20 per cent of the dairy cow population was insemi-nated artificially. A majority of these inseminations were to dairy sires in service in the East Tennessee Artificial Breeding Association. Since the East Tennessee Artificial Breeding Association was organized in November, 1947, there have been 332,614 inseminations to dairy sires. The best available estimates indicate that this represents over 90 per cent of the inseminations by commercial concerns in this area. It is evident that East Tennessee Artificial Breeding Association has had major responsibility for genetic improvement in dairy cattle production traits in this area. As the acceptance of A. I. continues to increase, sire selection committees will have more responsibility for the genetic improvement in dairy cattle production traits in the East Tennessee area. Therefore, it is important to determine the genetic improvement which has resulted from the use of A. I. in the upper East Tennessee area. Some preliminary studies in a few herds have shown the A. I . progeny to be superior to their dams and the DHIA herd average. Since these studies were limited to a few herds, and involved small numbers, their conclusions are inconclusive. The results could have been influenced by uncontrolled environmental conditions. Some environmental biases which could have been introduced are: the selection of herds studied, the change in the feeding and management practices, or differences in the season of freshening. This study was conducted to evaluate critically the influence on dairy cattle production traits that has resulted from the use of artificial insemination in the East Tennessee area

Tubeflight -A Review

A survey is made of theoretical and experimental work done as part of Project Tubeflight at Rensselaer Polytechnic Institute which has been directed at the development of a novel means of highspeed ground transportation. Tubeflight involves a vehicle, shaped much like an aircraft fuselage, which is supported by air cushion devices, and propels itself by one of several possible flow induction devices through a non-evacuated tube. The principal research areas reviewed are: the guideway, propulsion and power required, support, and small-scale experimentation

High-Precision Thermodynamics and Hagedorn Density of States

We compute the entropy density of the confined phase of QCD without quarks on the lattice to very high accuracy. The results are compared to the entropy density of free glueballs, where we include all the known glueball states below the two-particle threshold. We find that an excellent, parameter-free description of the entropy density between 0.7Tc and Tc is obtained by extending the spectrum with the exponential spectrum of the closed bosonic string.Comment: 4 pages, 3 figure

Quantum Link Models with Many Rishon Flavors and with Many Colors

Quantum link models are a novel formulation of gauge theories in terms of discrete degrees of freedom. These degrees of freedom are described by quantum operators acting in a finite-dimensional Hilbert space. We show that for certain representations of the operator algebra, the usual Yang-Mills action is recovered in the continuum limit. The quantum operators can be expressed as bilinears of fermionic creation and annihilation operators called rishons. Using the rishon representation the quantum link Hamiltonian can be expressed entirely in terms of color-neutral operators. This allows us to study the large N_c limit of this model. In the 't Hooft limit we find an area law for the Wilson loop and a mass gap. Furthermore, the strong coupling expansion is a topological expansion in which graphs with handles and boundaries are suppressed.Comment: Lattice2001(theorydevelop), poster by O. Baer and talk by B. Schlittgen, 6 page

Towards a strong-coupling theory of QCD at finite density

We apply strong-coupling perturbation theory to the QCD lattice Hamiltonian. We begin with naive, nearest-neighbor fermions and subsequently break the doubling symmetry with next-nearest-neighbor terms. The effective Hamiltonian is that of an antiferromagnet with an added kinetic term for baryonic "impurities," reminiscent of the t-J model of high-T_c superconductivity. As a first step, we fix the locations of the baryons and make them static. Following analyses of the t-J model, we apply large-N methods to obtain a phase diagram in the (N_c,N_f) plane at zero temperature and baryon density. Next we study a simplified U(3) toy model, in which we add baryons to the vacuum. We use a coherent state formalism to write a path integral which we analyze with mean field theory, obtaining a phase diagram in the (n_B,T) plane.Comment: Lattice2002(nonzerot) - Parallel talk and poster presented at Lattice 2002, Cambridge, MA, USA, June 2002. 6 pages, 6 EPS figure

Lessons Learned from Organizing a Multi-County Marriage Celebration Event

It is well documented that individuals in communities need and value opportunities to engage in marital education and enrichment programs. Often individuals are interested in learning strategies that will enhance their interpersonal relationships. One way in which this can be done is through educational events that focus on specific topics. This paper focuses on specific strategies and lessons learned in hosting a collaborative relationship enrichment event, Marriage Celebration, across multiple counties

Investigation of passive shock wave-boundary layer control for transonic airfoil drag reduction

The passive drag control concept, consisting of a porous surface with a cavity beneath it, was investigated with a 12-percent-thick circular arc and a 14-percent-thick supercritical airfoil mounted on the test section bottom wall. The porous surface was positioned in the shock wave/boundary layer interaction region. The flow circulating through the porous surface, from the downstream to the upstream of the terminating shock wave location, produced a lambda shock wave system and a pressure decrease in the downstream region minimizing the flow separation. The wake impact pressure data show an appreciably drag reduction with the porous surface at transonic speeds. To determine the optimum size of porosity and cavity, tunnel tests were conducted with different airfoil porosities, cavities and flow Mach numbers. A higher drag reduction was obtained by the 2.5 percent porosity and the 1/4-inch deep cavity

Alkali oxide-tantalum, niobium and antimony oxide ionic conductors

The phase equilibrium relations of four systems were investigated in detail. These consisted of sodium and potassium antimonates with antimony oxide and tantalum and niobium oxide with rubidium oxide as far as the ratio 4Rb2O:llB2O5 (B=Nb, Ta). The ternary system NaSbO3-Sb2O4-NaF was investigated extensively to determine the actual composition of the body centered cubic sodium antimonate. Various other binary and ternary oxide systems involving alkali oxides were examined in lesser detail. The phases synthesized were screened by ion exchange methods to determine mobility of the mobility of the alkali ion within the niobium, tantalum or antimony oxide (fluoride) structural framework. Five structure types warranted further investigation; these structure types are (1) hexagonal tungsten bronze (HTB), (2) pyrochlore, (3) the hybrid HTB-pyrochlore hexagonal ordered phases, (4) body centered cubic antimonates and (5) 2K2O:3Nb2O5. Although all of these phases exhibit good ion exchange properties only the pyrochlore was prepared with Na(+) ions as an equilibrium phase and as a low porosity ceramic. Sb(+3) in the channel interferes with ionic conductivity in this case, although relatively good ionic conductivity was found for the metastable Na(+) ion exchanged analogs of RbTa2O5F and KTaWO6 pyrochlore phases