Dynamical instability of differentially rotating stars

We study the dynamical instability against bar-mode deformation of differentially rotating stars. We performed numerical simulation and linear perturbation analysis adopting polytropic equations of state with the polytropic index $n=1$. It is found that rotating stars of a high degree of differential rotation are dynamically unstable even for the ratio of the kinetic energy to the gravitational potential energy of $O(0.01)$. Gravitational waves from the final nonaxisymmetric quasistationary states are calculated in the quadrupole formula. For rotating stars of mass $1.4M_{\odot}$ and radius several 10 km, gravitational waves have frequency several 100 Hz and effective amplitude $\sim 5 \times 10^{-22}$ at a distance of $\sim 100$ Mpc.Comment: 5 pages, 7 figures, accepted for publication in MNRA

Fuel injector characterization studies

The atomization of several general aviation piston engine manifold port fuel injectors was investigated. The injectors were installed in a test rig and operated under simulated conditions. Laser interferometric techniques were used to optically probe the spray droplet fields for droplet size and velocity at numerous spatial locations throughout the field

Analysis and testing of a new method for drop size measurement using laser scatter interferometry

Research was conducted on a laser light scatter detection method for measuring the size and velocity of spherical particles. The method is based upon the measurement of the interference fringe pattern produced by spheres passing through the intersection of two laser beams. A theoretical analysis of the method was carried out using the geometrical optics theory. Experimental verification of the theory was obtained by using monodisperse droplet streams. Several optical configurations were tested to identify all of the parametric effects upon the size measurements. Both off-axis forward and backscatter light detection were utilized. Simulated spray environments and fuel spray nozzles were used in the evaluation of the method. The measurements of the monodisperse drops showed complete agreement with the theoretical predictions. The method was demonstrated to be independent of the beam intensity and extinction resulting from the surrounding drops. Signal processing concepts were considered and a method was selected for development

The Origin and Development of the Italian Aria in the Baroque Period

The purpose of this paper is to study and identify the pertinent factors that established the operatic aria as a vocal solo form, to discover how these factors were applied and developed by the various composers of the Baroque period, and to gain a perspective of its historical value in music

Requirements for Air Force Cost Analysis

This research effort intends on identifying the knowledge, skills, abilities necessary for cost analysts to be effective decision support members. The purpose of this research is to determine what levels of education, training, and knowledge are needed by cost analysts in the current career field and in the foreseeable future. It also assesses whether cost analysts associate the levels of knowledge, skills, and abilities as requirements in fulfilling cost analyst duties. From this analysis, a suggested undergraduate education, master’s degree program, and certifications were created for current and future cost analysts to strive to achieve. To accomplish this objective, personal interviews were conducted and utilized. The recommendations of this study are intended to assist cost analysts in attaining knowledge, skills, and abilities necessary in contributing and supporting as a decision support member

NEW DEAL EXPERIMENTATION AND THE POLITICAL ECONOMY OF THE YANKTON SIOUX, 1930-1934

Franklin Delano Roosevelt\u27s election to the presidency in 1932 signaled a mandate for sweeping reform at the federal level to lift the nation out of the economic turbulence of the Great Depression. Under Commissioner of Indian Affairs John Collier, the Bureau of Indian Affairs (BIA) joined other agencies in launching policies to rebuild economic stability. Much of the scholarship on the Indian New Deal to date necessarily focuses on the centerpiece of Collier\u27s reform efforts: the Indian Reorganization Act (IRA). But prior to tribal consideration of the IRA, the Roosevelt administration undertook a series of steps in an attempt to mitigate the most dramatic losses experienced by individuals in rural America. These early short-term relief measures played an important role in Native American perception of Collier\u27s larger efforts. Study of these measures also provides important lessons for scholars to use in evaluating the positive and negative effects of the Indian New Deal in its entirety

NEW DEAL EXPERIMENTATION AND THE POLITICAL ECONOMY OF THE YANKTON SIOUX, 1930-1934

Franklin Delano Roosevelt\u27s election to the presidency in 1932 signaled a mandate for sweeping reform at the federal level to lift the nation out of the economic turbulence of the Great Depression. Under Commissioner of Indian Affairs John Collier, the Bureau of Indian Affairs (BIA) joined other agencies in launching policies to rebuild economic stability. Much of the scholarship on the Indian New Deal to date necessarily focuses on the centerpiece of Collier\u27s reform efforts: the Indian Reorganization Act (IRA). But prior to tribal consideration of the IRA, the Roosevelt administration undertook a series of steps in an attempt to mitigate the most dramatic losses experienced by individuals in rural America. These early short-term relief measures played an important role in Native American perception of Collier\u27s larger efforts. Study of these measures also provides important lessons for scholars to use in evaluating the positive and negative effects of the Indian New Deal in its entirety

Angiotensin II and Aldosterone Increase with Fasting in Breeding Adult Male Northern Elephant Seals (Mirounga angustirostris)

The renin‐angiotensin‐aldosterone system (RAAS) appears to contribute significantly to osmoregulation of fasting northern elephant seal (Mirounga angustirostris) pups; however, RAAS has not been characterized in fasting adult seals. Therefore, this study examined the contribution of RAAS to water turnover rates in fasting adult male northern elephant seals. Blood samples were obtained twice during their breeding fast at an interval of 6.5 wk, and water efflux rate was estimated by isotopic dilution during the same period. Serum electrolytes (Na+, K+, Cl−) and osmolality were unaltered between the two sampling periods, indicating ionic and osmotic homeostasis during the fast. Despite the lack of an increase in vasopressin, serum angiotensin II and aldosterone were increased and were significantly and positively correlated. Changes in aldosterone concentration and water efflux rate were significantly and negatively correlated, suggesting that the greater the increase in aldosterone, the smaller the loss of water. Adult male seals maintain ionic and osmotic homeostasis similar to that of fasting weaned pups, and this homeostasis appears to be mediated, at least in part, by RAAS, which probably contributes to increased water retention as well. The hormonal mechanisms by which northern elephant seals maintain water and electrolyte balance during fasting conditions appear to be similar regardless of age