A summary of research in elementary school social studies (1951-1955).

Thesis (Ed.M.)--Boston Universit

Analytical investigation of solid rocket nozzle failure

On April 5, 1983, an Inertial Upper Stage (IUS) spacecraft experienced loss of control during the burn of the second of two solid rocket motors. The anomaly investigation showed the cause to be a malfunction of the solid rocket motor. This paper presents a description of the IUS system, a failure analysis summary, an account of the thermal testing and computer modeling done at Marshall Space Flight Center, a comparison of analysis results with thermal data obtained from motor static tests, and describes some of the design enhancement incorporated to prevent recurrence of the anomaly

Spin-spin Correlation in Some Excited States of Transverse Ising Model

We consider the transverse Ising model in one dimension with nearest-neighbour interaction and calculate exactly the longitudinal spin-spin correlation for a class of excited states. These states are known to play an important role in the perturbative treatment of one-dimensional transverse Ising model with frustrated second-neighbour interaction. To calculate the correlation, we follow the earlier procedure of Wu, use Szego's theorem and also use Fisher-Hartwig conjecture. The result is that the correlation decays algebraically with distance ($n$) as $1/\surd n$ and is oscillatory or non-oscillatory depending on the magnitude of the transverse field.Comment: 5 pages, 1 figur

The Role of Torsion/Torsion Coupling in the Vibrational Spectrum of Cis−Cis HOONO

A three-dimensional model of the vibrational dynamics of HOONO is investigated. This model focuses on the couplings between the OH stretch vibration and the two torsions. The model is based on electronic energies, calculated at the CCSD(T)/cc-pVTZ level of theory and basis and dipole moment functions calculated at the CCSD/aug-cc-pVDZ level. The resulting points were fit to explicit functional forms, and the energies, wave functions, and intensities were evaluated using an approach in which the OH stretching motion was adiabatically separated from the torsional modes. It is found that the HOON torsion is strongly coupled to both the OONO torsion and OH stretch. Despite this, many of the conclusions that were drawn from earlier two-dimensional treatments, which did not include the OONO torsion, hold up on a semiquantitative level. In addition, we use this model to investigate the assignment of recently reported matrix isolated spectra of HOONO and DOONO. Finally, by comparing the results of this three-dimensional calculation to two-dimensional calculations and to the results of second-order perturbation theory, we investigate the question of how one determines the size of the reduced-dimensional system that is needed to describe the vibrational spectrum of molecules, like HOONO, that contain several large amplitude motions

Spin and energy correlations in the one dimensional spin 1/2 Heisenberg model

In this paper, we study the spin and energy dynamic correlations of the one dimensional spin 1/2 Heisenberg model, using mostly exact diagonalization numerical techniques. In particular, observing that the uniform spin and energy currents decay to finite values at long times, we argue for the absence of spin and energy diffusion in the easy plane anisotropic Heisenberg model.Comment: 10 pages, 3 figures, gzipped postscrip

An Empirical Examination of the Factors Affecting Remittance by Mexican Migrants in the United States

Mexico has reported workers remittances to equal $16.6 billion in 2004, which constitutes nearly 2.5 percent of Mexicos GDP, exceeding the inflows from direct foreign investment and aid. We develop a model of remittances based on a net income concept. The model is used to generate a series of testable hypotheses. We test these hypotheses using what we term a type II generalized ordered probit model based on survey data for Mexican Migrants. Our results are generally consistent with standard utility maximization theory, and more specifically are consistent with a net income hypothesis. we find, for example, that migrant income is a strong positive determinant of remittance levels except for the lowest remittance category. We also find that migrants remit more when they have more family members in Mexico and fewer in the U.S., when they own land and real estate in Mexico, and when they plan on returning to Mexico relatively soon.Labor and Human Capital,

A revision of the Morgan Test of Logical Reasoning

Do we learn to reason logically just as we learn grammar or estimating distances? Philosophers usually say we do and have taught logic as a discipline for thousands of years. They are generally not content to teach about logic, or in the history of it; they generally state their intent is to teach logic for everyday thinking . Appendix VI is a personal communication to the author from a philosopher stating this clearly and comparing the skill of logical reasoning with the skill of using grammar. Or is logical reasoning a relatively inherent trait, as intelligence is generally assumed to be? We all have the subtle feeling that some are more logical than others and usually make this judgment without knowledge of who has been educated in logic. One group of psychologists went so far as to call a reasoning test a status-free test of intelligence apparently assuming not only that logic is innate but is also virtually the whole of innate mental ability

Antarctic Meteorites: A Statistical Look at a Uniquely Valuable Resource

As of the end of the 2018-19 field season, the U.S. Antarctic meteorite program has surpassed 23,000 meteorites collected. The U.S. collection is valuable in that it is classified in its entirety. The systematic methods employed to collect the meteorites have provided meteorites of more than 40 types, many of which are the first of their type ever recognized. One of the early drivers for consistent and methodical characterization of the entire U.S. Antarctic collection was to allow statistical comparisons. Early statistical assessments of the U.S. Antarctic collection examined mass distributions and the relative frequency of meteorite types as well as comparisons to a defined set of modern falls. Using these statistics argued that the flux of H chondrites changed over time used model size distributions to deconstruct the contribution of wind movement, meteorite supply and search losses to the Antarctic collection. Mass-based statistics and size distribution comparisons were examined by investigated various aspects of the statistics, including comparison with modern falls/Saharan finds. Also discuss geospatial statistics provides a comprehensive overview of the statistics of the Antarctic collections for the first 35 seasons of U.S. collection by ANSMET. Here we build upon that assessment and that from