Spectroscopy of comets

Observations of NH2, OI, CH, CO(+), CO2(+), H2O(+), and N2(+) in optical spectra of comets represent ionization and dissociation product abundances of N2, NH3, H2O, CH4, CO2, and CO. The primary objectives are to determine: (1) accurate production rates for the observed species, and (2) accurate relative abundances of condensates in a sample of comet nuclei. The ultimate goal is to constrain models of comet formation and chemical processing in the outer primordial solar nebula

Ground-based cometary spectroscopy

The observational problems presented by bright comets near perihelion are discussed. High and low resolution spectra (3100-800A) of the bright comets Kohoutek, Kobayashi-Berger-Milon, West and d'Arrest are presented. Digital reduction of calibrated photographic spectra to relative intensity versus wavelength, can provide useful information. The reduction of comet spectra to absolute intensities involves, however, large uncertainties and should be interpreted cautiously. Data on recent comets lead to the following results: tentative identification of a new ion in the tail of comets, namely, NH(+); spectroscopic resolution of the fragmented nucleus of comet West; and an accurate monochromatic intensity profile of the Co+ emission (4020A) in comet West

ALLOCATION PROBLEMS OF PUBLIC LANDS IN THE WEST

Increasing interest in the federally owned lands by individuals and groups representing a broad cross section of society has intensified public land management problems. Pressures for preservation, conservation, and additional non-market uses have resulted in management conflicts. Economic intelligence could contribute to improved decision making by federal agencies charged with public land management. However, inadequate past research attention related to economic problems of public lands presently precludes an optimum input from economists. Articulation of problem areas and economic issues is necessary for developing meaningful research priorities. This article identifies some elements of the problem and suggests some potentially rewarding areas for economic research.Land Economics/Use,

Employment Retention Essentials

Employment retention is one of the critical challenges facing the workforce field today. For any organization that seeks to improve retention services, "Employment Retention Essentials" is an invaluable resource. User-friendly and filled with practical ideas, this guide offers concrete tools for keeping people working, including tips on how to involve employers, build relationships and stay in contact with participants

Going to Work with a Criminal Record: Lessons from the Fathers at Work Initiative

Many of the 650,000 adults released from American prisons each year find their way to One-Stops or community-based, faith-based and other organizations that provide employment services. Yet relatively few of these organizations specifically target former prisoners. Workforce development practitioners have experience with a wide range of job seekers, but a great number of them are looking for additional guidance about the complexities of connecting formerly incarcerated people to the labor market and helping them stay on the job.Going to Work with a Criminal Record was developed to help meet this need. It is based on lessons from the Fathers at Work initiative, a three-year, six-site demonstration funded by the Charles Stewart Mott Foundation to help young, noncustodial fathers achieve increased employment and earnings, involvement in their childrens lives, and more consistent financial support of their children. The report describes seven fundamental lessons workforce organizations should consider as they help formerly incarcerated people move toward stable employment, along with a more detailed discussion of how program staff can put these lessons into practice. It outlines how to avoid mistakes and how to develop important relationships, including with employers, parole officers and the local child support enforcement agency

Revenue sharing and local public expenditure: old questions, new answers

A review of the economic literature on the impact of revenue sharing on local government expenditures, a critique of previous explanations of this pattern, and a summary of a new bureaucratic theory.Local finance ; Revenue sharing

A bureaucratic theory of flypaper effects

An analysis of two competing theories, the median voter model and the bureaucratic model, as they relate to how noncategorical grants to communities are spent.Social choice ; Local government ; Local finance

Chemical abundance of comets

Observations of NH2, (OI) and molecular ion spectra in comets represent virtually all of the volatile fraction of a comet nucleus. Their study leads to the N2, NH3, H2O, CO2, CO content of the nucleus, and thus to important constraints on models of comet formation and chemical processing in the primitive solar nebula. The observations of Comet Halley provide the opportunity for the first comprehensive determination of the abundances in a comet nucleus. The carbon isotope abundance ratio 12 C/13 C = 65 plus or minus 8 has been determined for Comet Halley from resolved rotational line structure in the CN B-X (0,0) band. The ratio is approximately 30 pct lower than the solar system value, 89, indicating either an enhancement of 13CN or a depletion of 12CN in the comet. Scenarios consistent with the observed carbon isotope ratio are: (1) formation of the comet at the periphery of the solar nebula in a fractionation-enriched 13CN region, or hidden from 12CN enrichment sources, and (2) capture of an interestellar comet. Long-slit charge coupled device (CCD) spectra obtained at the time of the spacecraft encounter of Comet Halley have also been analyzed. Scale lengths, production rates and column densities of CH, CN, C2 and NH2 were determined

Targeting Industries, Training Workers and Improving Opportunities: The Final Report from the Sectoral Employment Initiative

Over the past 30 years, American workers have faced daunting challenges, including declines in real wages and dwindling upward mobility. Paths to advance within companies have deteriorated, leaving many low-skilled workers "stuck" indefinitely in low-wage jobs -- and swelling the ranks of the working poor. As opportunities for less-educated workers to access well-paying jobs grow scarce, it is clear that our nation requires new approaches to workforce development.In a departure from traditional strategies, some workforce organizations have begun to implement services and activities that focus on the needs of specific industry sectors. By identifying local sectors that lack workers -- which might range from health care to manufacturing to construction -- these organizations can help low-income workers acquire the specific skills they need to fill available positions. To explore the potential of this approach, P/PV launched the Sectoral Employment Initiative (SEI) in 1998, with support from the Charles Stewart Mott Foundation. This final report relies on data gathered during interviews with staff members at the SEI organizations and other key players in the targeted sectors, site visits, reviews of program documentation, and baseline and follow-up interviews with program participants focusing on a range of outcomes, including employment, earnings, education, housing and household income. The report presents key findings and explores some of the challenges sectoral programs encountered

Targeting Industries, Training Workers and Improving Opportunities: The Final Report from the Sectoral Employment Initiative Executive Summary

This executive summary provides a brief look at the key findings and challenges sectoral programs encountered while participating in the Sectoral Employment Initiative (SEI). By identifying local sectors that lack workers -- which might range from health care to manufacturing to construction -- these organizations were shown, in many cases, to help low-income workers acquire the specific skills they need to fill available positions