Robert M. St. John

Electron Excitation of the First Positive Bands of N 2 and of the First Negative and Meinel Bands of N 2

Absolute optical cross sections for the excitation from the X2∑g+ ground state of N2 by electron impact have been measured for 39 N2 first positive bands (B3Πg–A3∑u+), 12 N2+ first negative bands (B2∑u–X2∑g+), and 10 N2+ Meinel bands (A2Πu–X2∑g+). Relative excitation functions are presented for N2 first negative bands with v′ values from 0 through 9 for 0 to 50 eV, for the (0,0) and (1,0) N2+ first negative bands for 0 to 450 eV, and for the (3,0) and (4,1) N2+ Meinel bands for 0 to 450 eV. The first-positive excitation functions exhibit sharp peaks at 10–12 eV and at 14–15 eV and exhibit an S-shaped change in slope about midway between onset and the maximum of the first sharp peak. The first negative and Meinel excitation functions have broad maxima at about 120 eV and 100 eV.

Point-of-Sale Marketing of Tobacco Products: Taking Advantage of the Socially Disadvantaged?

With increasing regulation of tobacco industry marketing practices, point-of-sale advertising has become an important channel for promoting tobacco products. One hundred and ten convenience stores in Oklahoma County were surveyed for tobacco-related advertising. There were significantly more point-of-sale tobacco advertisements in low-income and minority neighborhoods than in better educated, higher-income, predominantly White neighborhoods. Storeowners or managers were also interviewed to determine who has decision-making power regarding store signage and placement, and to elicit perceptions of industry tactics. Contracts with tobacco companies leave storeowners with little or no control over promotion of tobacco products within their store, and many are unaware of the implications of the tobacco industry point-of-sale practices. Local ordinances that regulated outdoor signage reduced outdoor tobacco advertisements, as well as tobacco signage and promotions within the store. Policy change, rather than education targeting storeowners, is recommended as the most effective strategy for reducing point-of-sale tobacco advertising.

Design of a high density atomic hydrogen source and determination of Balmer cross sections

A high density beam of atomic hydrogen was obtained from a Wood discharge and utilized in the measurement of electron‐hydrogen atom collision cross sections. Balmer optical excitation cross sections were determined from observations of crossed electronic and atomic beams. In order to choose Wood discharge parameters to obtain a high degree of dissociation under conditions of a high gas throughput, the differential equations relating the production, loss, and flow of hydrogen atoms and molecules were formulated and solved. The solutions show that recombination of atoms on the metal electrodes greatly reduces the degree of dissociation in large diameter tubes. They further show that this effect can be nearly eliminated by placing short small diameter tubes, called constrictions, between the electrodes and the main tube. A Wood tube 2 cm in diameter and 2 m in length with these constrictions was constructed which produced an atomic to molecular density ratio of 11 at a throughput of 1000 mtorr · liter/sec. T...

Determinants of Health-Related Quality of Life Among Older American Indians and Alaska Natives

During the past decade, health-related quality of life (HRQoL) has been recognized in both clinical and community health research as an important health outcome and a needed supplement to conventional health outcomes. The authors provide a profile of HRQoL and examine its determinants among American Indians and Alaska Natives aged 50 or older. Multivariate analyses of cross-sectional survey data from the 1996-1998 Centers for Disease Control Behavioral Risk Factor Surveillance System were conducted. Thirty-four percent of the sample reported fair or poor self-rated health. The mean number of poor health days in the past month ranged from 4 to 6 on different measures. Age, sex, education, annual household income, employment status, hypertension, and obesity were associated with aspects of HRQoL. Further research aimed at eliminating health disparities among this population should focus on identifying additional indicators of poor HRQoL and on understanding variables that mediate the relationship between disease and HRQoL.

Collisional Transfer of Excitation Energy in Helium

Recent absolute measurements of many helium excitation functions at low pressure and of the singlet and triplet D functions at several pressures have allowed an extension and upgrading of the multiple-state-transfer process.Atoms excited to an n1P level are converted to a mixed singlet–triplet F state by an atomic collision. Low-lying singlet and triplet D levels are fed by the many F states thus populated.Apparent excitation functions were computed by machine for the 33D, 43D, and 41D states and compared with the experimental excitation functions. The computed curves best match the experimental curves when it is assumed that: (a) the transfer cross section for the nth set of 1P–F states is proportional to n1 or n2, and (b) the 1F3 and 3F3 components of the mixed state are active in the transfer–cascade processes, while the 3F2,4 states are inactive.The energy is primarily transferred through n1P–nF sets of states with n≤15.

Pyrex Demountable Photomultiplier Refrigerator

The measurement of extremely small light fluxes photoelectrically requires the use of a multiplier phototube operated at the temperature of liquid air. A refrigerator for the application is described that is easy to construct and whose plan can be simply adapted to any type and size of tube.

Erratum: Production of Excitation and Ionization in Helium by Single‐Electron Impact

The production of excited He+ ions by single‐electron impact collisions with ground‐state helium atoms has been observed by the optical method. The absolute value of the cross section for the collision process yielding the n=4→n=3 transitions (4686 A) in He+ was determined for incident electron energies ranging from 60 to 470 eV. The excitation—ionization cross section exhibited a single broad maximum at 200 eV with an onset at 75 eV. The peak value of the cross section was 4.2×10—21 cm2. Stepwise ionization and excitation was nowhere in evidence. The excitation—ionization function obtained at a number of gas pressures was independent of pressure. Light yield was proportional to the electron beam currents. Comparison with previous experimental work and with theoretical calculations were made.

Improved Pyrex Demountable Photomultiplier Refrigerator

An improved refrigerator constructed of Pyrex glass is described. This refrigerator is designed to keep a photomultiplier tube at the temperature of liquid air and in a vacuum. (N.W.R.)

Resistance to influenza vaccination: Psychographics, audience segments, and potential promotions to increase vaccination

Except for individuals 65 years of age and older, no other group in the United States has an influenza vaccination rate above one-third of the population, even among groups that the Centers for Disease Control and Prevention (CDC) recommend for priority annual seasonal influenza vaccination. To improve the vaccination rate we need to know more about influenza vaccine psychographics among indifferent or resistant individuals or the attitudes, beliefs, opinions, and values surrounding their decision not to obtain annual vaccination. This formative research project is based on eight focus group discussions with 74 individuals from groups that do not participate in influenza vaccination at rates similar to the general population and/or are members of identifiable high-risk groups about their perceptions and beliefs about the flu shot. Three audience segments were identified: Plans to Get, Needs More Information, and Makes You Sick Because they have strongly held negative views toward the product, no special intervention should be directed toward the Makes You Sick segment. Since the actual product cannot be changed (vaccine), different aspects of the marketing mix of price, place, and promotion need to be adjusted to influence the Plans to Get and Needs More Information segments to obtain a vaccination. Ideas for appropriate promotional messages are offered.

EXCITATION OF THE 4F STATES OF HELIUM.

Recent studies of the population processes of the 4F state in helium by observation of the infrared radiation from this state have given direct experimental evidence for the 41P to 4F excitation-transfer process. The behavior of the apparent cross sections of the 41P and 4F states with pressure is used to evaluate the cross section for the excitation transfer and the cross section for electronic excitation to the 4F state. Analysis of the data indicates a cross section of 1.5 × 10−14 cm2 for the 41P to 4F transfer and 1.6 × 10−19 cm2 at 100 eV for the electron excitation plus cascade of the 4F state. Apparent cross sections of the 4F state are presented at high and low pressures from onset to 450 eV. At high pressure the apparent cross section is similar to that of the 41P state. As the pressure is lowered, the shape of the excitation function approaches that of a 1D state.