Development of low cost ablative nozzles for solid propellant rocket motors, volume 1 Final report

Evaluating low cost ablative materials for use in large solid propellant rocket motor

Fast scan infrared detection and measuring instrument monthly progress report, oct. 1-31, 1964

Optics, scan, detector, and product design of fast scan infrared detection and measuring instrumen

Reconstruction of primordial density fields

The Monge-Ampere-Kantorovich (MAK) reconstruction is tested against cosmological N-body simulations. Using only the present mass distribution sampled with particles, and the assumption of homogeneity of the primordial distribution, MAK recovers for each particle the non-linear displacement field between its present position and its Lagrangian position on a primordial uniform grid. To test the method, we examine a standard LCDM N-body simulation with Gaussian initial conditions and 6 models with non-Gaussian initial conditions: a chi-squared model, a model with primordial voids and four weakly non-Gaussian models. Our extensive analyses of the Gaussian simulation show that the level of accuracy of the reconstruction of the nonlinear displacement field achieved by MAK is unprecedented, at scales as small as about 3 Mpc. In particular, it captures in a nontrivial way the nonlinear contribution from gravitational instability, well beyond the Zel'dovich approximation. This is also confirmed by our analyses of the non-Gaussian samples. Applying the spherical collapse model to the probability distribution function of the divergence of the displacement field, we also show that from a well-reconstructed displacement field, such as that given by MAK, it is possible to accurately disentangle dynamical contributions induced by gravitational clustering from possible initial non-Gaussianities, allowing one to efficiently test the non-Gaussian nature of the primordial fluctuations. In addition, a simple application of MAK using the Zel'dovich approximation allows one to also recover accurately the present-day peculiar velocity field on scales of about 8 Mpc.Comment: Version to appear in MNRAS, 24 pages, 21 figures appearing (uses 35 figure files), 1 tabl

A Guide to Disability Statistics from the Panel Study of Income Dynamics

This User Guide provides information on the Panel Study of Income Dynamics (PSID). The 2003 PSID is a nationally representative sample of over 7,000 families. The PSID began in 1968 with a sample of 4,800 families and re-interviewed these families on an annual basis from 1968-1997. Since then, it has re-interviewed them biennially. Following the same families and individuals since 1968, the PSID collects data on economic, health, and social behavior. (See http://psidonline.isr.umich.edu/ for detailed information on the PSID). Initially, the PSID identified disability by asking the head of the household whether he, or she when no adult male is present, had a physical or nervous condition that limits his or her ability to work. In 1981 the PSID began asking the head this question with respect to his spouse. Additional questions that provide an opportunity to expand this definition of disability were included in 2003. The User Guide makes use of these new questions to estimate the size of the population with disabilities and the prevalence rate of disability in the population, as well as the employment rate and level of economic well-being. The major strength of the PSID for those interested in disability research is its long-running information on families. No other nationally representative survey has captured such detailed information on the same families over such a long time. Such longitudinal data allows researchers to better understand the dynamics of the disability process and its consequences. Here we demonstrate the comparative advantage of the PSID over traditional cross-sectional data sets. Using the PSID, we identify persons with disabilities of various lengths and show the sensitivity of alternative definitions of the population with disabilities based on the duration of a disability. We also measure how the employment and economic well-being of individuals changes following the onset of a disability. Finally, we provide examples of how the PSID has been used with the German Socio-Economic Panel (GSOEP) to compare the employment and economic well-being of working-age people with disabilities in the United States and Germany. This analysis uses the equivalized data from these longitudinal datasets contained in the Cornell University Cross-National Equivalent File (CNEF)

Understanding angular momentum transport in red giants: the case of KIC 7341231

Context. Thanks to recent asteroseismic observations, it has been possible to infer the radial differential rotation profile of subgiants and red giants. Aims. We want to reproduce through modeling the observed rotation profile of the early red giant KIC 7341231 and constrain the physical mechanisms responsible for angular momentum transport in stellar interiors. Methods. We compute models of KIC 7341231 including a treatment of shellular rotation and we compare the rotation profiles obtained with the one derived by Deheuvels et al. (2012). We then modify some modeling parameters in order to quantify their effect on the obtained rotation profile. Moreover, we mimic a powerful angular momentum transport during the Main Sequence and study its effect on the evolution of the rotation profile during the subgiant and red giant phases. Results. We show that meridional circulation and shear mixing alone produce a rotation profile for KIC 7341231 too steep compared to the observed one. An additional mechanism is then needed to increase the internal transport of angular momentum. We find that this undetermined mechanism has to be efficient not only during the Main Sequence but also during the much quicker subgiant phase. Moreover, we point out the importance of studying the whole rotational history of a star in order to explain its rotation profile during the red giant evolution.Comment: 8 pages, 8 figures, 5 table

The Effects of a Vegetarian Diet

The purpose of this paper is to equip individuals with knowledge of the effects of a vegetarian diet. This paper will provide factual research for a group of individuals willing to investigate how certain dietary choices can provide benefits for current and future generations in all aspects of life. The consumption of a vegetarian diet impacts a person’s health, the environment, the economy, and society. This concept is examined through the idea of nutrition ecology. Exploring concepts related to these four components will provide insight into the food consumption choices that people make while also understanding the effect it may play. Many individuals choose to consume a vegetarian diet for health reasons, such as weight loss, cholesterol issues or diabetes. Other individuals choose to eat a vegetarian diet for animal welfare reasons or environmental issues, such as sustainability concerns. Whatever the decision-making factor may be, the effects of a vegetarian diet possess positive outcomes for the individual, the environment, the economy, and society while maintaining an ecological balance

EVALUATING INCENTIVE PAYMENT PROGRAMS THROUGH AGGREGATE PRODUCTION RESPONSE: THE CASE OF MOHAIR

Production Economics,

Characterizing the propagation of gravity waves in 3D nonlinear simulations of solar-like stars

The revolution of helio- and asteroseismology provides access to the detailed properties of stellar interiors by studying the star's oscillation modes. Among them, gravity (g) modes are formed by constructive interferences between progressive internal gravity waves (IGWs), propagating in stellar radiative zones. Our new 3D nonlinear simulations of the interior of a solar-like star allows us to study the excitation, propagation, and dissipation of these waves. The aim of this article is to clarify our understanding of the behavior of IGWs in a 3D radiative zone and to provide a clear overview of their properties. We use a method of frequency filtering that reveals the path of {individual} gravity waves of different frequencies in the radiative zone. We are able to identify the region of propagation of different waves in 2D and 3D, to compare them to the linear raytracing theory and to distinguish between propagative and standing waves (g modes). We also show that the energy carried by waves is distributed in different planes in the sphere, depending on their azimuthal wave number. We are able to isolate individual IGWs from a complex spectrum and to study their propagation in space and time. In particular, we highlight in this paper the necessity of studying the propagation of waves in 3D spherical geometry, since the distribution of their energy is not equipartitioned in the sphere.Comment: 14 pages, 12 figues, accepted by Astronomy & Astrophysic

CP and related phenomena in the context of Stellar Evolution

We review the interaction in intermediate and high mass stars between their evolution and magnetic and chemical properties. We describe the theory of Ap-star `fossil' fields, before touching on the expected secular diffusive processes which give rise to evolution of the field. We then present recent results from a spectropolarimetric survey of Herbig Ae/Be stars, showing that magnetic fields of the kind seen on the main-sequence already exist during the pre-main sequence phase, in agreement with fossil field theory, and that the origin of the slow rotation of Ap/Bp stars also lies early in the pre-main sequence evolution; we also present results confirming a lack of stars with fields below a few hundred gauss. We then seek which macroscopic motions compete with atomic diffusion in determining the surface abundances of AmFm stars. While turbulent transport and mass loss, in competition with atomic diffusion, are both able to explain observed surface abundances, the interior abundance distribution is different enough to potentially lead to a test using asterosismology. Finally we review progress on the turbulence-driving and mixing processes in stellar radiative zones.Comment: Proceedings of IAU GA in Rio, JD4 on Ap stars; 10 pages, 7 figure