Chemical Environment Selectivity in Mössbauer Diffraction from 57Fe3Al

Mössbauer diffraction was used to measure different autocorrelation functions for 57Fe atoms in different chemical environments. The sample was polycrystalline 57Fe3Al with the ordered DO3 structure. Diffraction peaks from a fcc structure with a doubled unit cell were detected when the incident radiation was tuned to the Mössbauer resonance of the Wyckoff 4(b) Fe site, but not for tuning to the 8(c) site, thereby distinguishing the spatial arrangements of these two Fe sites

Vibrational state dependence of ionic rotational branching ratios in resonance enhanced multiphoton ionization of CH

We show that rapid evolution of a Rydberg orbital with internuclear distance in a resonance enhanced multiphoton ionization (REMPI) process can have a profound influence on the production of molecular ions in alternative rotational states. This is illustrated by calculations of ionic rotational branching ratios for (2+1′) REMPI via the O11 (20.5) branch of the E′ ^2Σ^+(3pσ) Rydberg state of CH. The rotational propensity rule for ionization changes from ΔN=odd (ΔN=N_+−N_i) at lower vibrational excitation, as expected from the ΔN+l=odd selection rule, to ΔN=even at higher vibrational levels. This effect is expected to be quite general and should be most readily observable in diatomic hydrides

Studies related to the design of a magnetic suspension and balance system Interim technical report, Dec. 1964 - Jan. 1966

Magnetic suspension and balance system for use in hypersonic flow apparatu

Local Chemical Environments and the Phonon Partial Densities of States of 57Fe in 57Fe3Al

Inelastic nuclear resonant scattering spectra were measured on alloys of Fe3Al that were chemically disordered, partially ordered, and D03 ordered. The features in the phonon partial density of states of 57Fe were found to change systematically with chemical short-range order in the alloy. Changes in the phonon partial density of states were modeled successfully by assigning vibrational spectra to 57Fe atoms in different first-nearest-neighbor chemical environments

Mössbauer diffractometry on polycrystalline (57)Fe3Al

A Mossbauer powder diffractometer was used to measure diffraction patterns from polycrystalline foils of (Fe3Al)-Fe-57. The intensities of Bragg diffractions were measured as a function of the energy of the incident photon. The bee fundamental diffractions showed large changes in intensity as the incident energy was tuned through the nuclear resonances. These variations of diffraction intensity with incident energy were calculated with reasonable success using a kinematical theory of diffraction that included effects of coherent interference between x-ray Rayleigh scattering and, more importantly for these samples, Mossbauer scattering from nuclei having different hyperfine magnetic fields

A hierarchical Bayesian model for predicting ecological interactions using scaled evolutionary relationships

Identifying undocumented or potential future interactions among species is a challenge facing modern ecologists. Recent link prediction methods rely on trait data, however large species interaction databases are typically sparse and covariates are limited to only a fraction of species. On the other hand, evolutionary relationships, encoded as phylogenetic trees, can act as proxies for underlying traits and historical patterns of parasite sharing among hosts. We show that using a network-based conditional model, phylogenetic information provides strong predictive power in a recently published global database of host-parasite interactions. By scaling the phylogeny using an evolutionary model, our method allows for biological interpretation often missing from latent variable models. To further improve on the phylogeny-only model, we combine a hierarchical Bayesian latent score framework for bipartite graphs that accounts for the number of interactions per species with the host dependence informed by phylogeny. Combining the two information sources yields significant improvement in predictive accuracy over each of the submodels alone. As many interaction networks are constructed from presence-only data, we extend the model by integrating a correction mechanism for missing interactions, which proves valuable in reducing uncertainty in unobserved interactions.Comment: To appear in the Annals of Applied Statistic

Ride quality meter

A ride quality meter is disclosed that automatically transforms vibration and noise measurements into a single number index of passenger discomfort. The noise measurements are converted into a noise discomfort value. The vibrations are converted into single axis discomfort values which are then converted into a combined axis discomfort value. The combined axis discomfort value is corrected for time duration and then summed with the noise discomfort value to obtain a total discomfort value

Asia region population projections : 1989-90 edition

Of the 90 million people added to world population this year, half live in the Asia region. Asia's contribution to world population growth is proportional to its size and dwarfs the contribution of every other region. The scale of this contribution may be illustrated by the fact that India is adding to its population every year as many people as live in Australia. This paper studies population projections, covering almost two centuries from 1985 to 2150. The length of the projection period was chosen to allow populations to approach stability, which for several takes essentially the entire period. The paper begins with an introduction which explains what projection results are provided in the detailed tables, describes the projection methodology, and summarizes and interprets the main results.Health Monitoring&Evaluation,Health Indicators,Health Information&Communications Technologies,,Demographics

Africa region population projections : 1989-90 edition

The majority of populations in the Sub Saharan Africa region are growing rapidly. In some countries, where the average woman continues to have seven or more births, growth is as rapid as 4 percent a year. The population of the region as a whole is likely to double in slightly more than two decades, and after that, the region will be contributing more to annual world population growth than the far larger Asia region. The projections in this paper cover almost two centuries, from 1985 to 2150. The length of the projection period was chosen to allow populations to approach stability, which for several takes essentially the entire period. The paper begins with an introduction which explains what projection results are provided in the detailed tables, describes the projection methodology, and summarizes and interprets the main results.Health Information&Communications Technologies,,Demographics,Health Monitoring&Evaluation,Health Indicators

Africa region population projections : 1990-91

As recently as the mid-1970s, the Africa region had a smaller population than the Asia, the Latin American and the Caribbean, or the Europe, Middle East, and North Africa regions. Explosive population growth of more than 3 percent per year, projected to decline only gradually, will make Africa the second largest region by 2005. Its share of the world's population will increase from less than 10 percent now to 20 percent in the middle of the next century and to 25 percent when stationarity is finally reached. Vital rates vary relatively little among the subregions of sub-Saharan Africa. Fertility is uniformly high, with the total fertility rate higher than 6 children per woman. Linked with high fertility are high infant mortality rates, which are above 100 per thousand births for subregions. A few countries - Botswana, Zimbabwe, and Kenya - are leading the way in the African fertility transition. Recent fertility surveys in these countries show an increase in the use of contraceptives and the first evidence of fertility decline. It is assumed in the projections that this trend will spread to other countries. Most African governments now report their country's population growth rates as too high.Demographics,Health Indicators,Health Information&Communications Technologies,,Earth Sciences&GIS