Spoken words

Chiefly tablesIncludes bibliographical referencesSupported in part by the National Institute of Education under contract no. US-NIE-C-400-76-011

\u3ci\u3eBottomfeeders\u3c/i\u3e

Bottomfeeders is a collection of short fiction. It includes stories concerning life, death, hoboes, wrestling, videogames, and cropdusters, among other things. It is both very serious and impossibly dumb, as is the way of things

Aerodynamic behaviour of bridges

For a number of years, under various contracts, the Department of Aeronautics and Fluid Mechanics has been wind-tunnel testing bridge models for static loads. A recent development has been to include dynamic testing of models to determine the stability of the bridge in winds. The interest of the writer was in applying aeroelstic techniques to the prediction of the stability of the bridge models. Tests on section models of a proposed road bridge were carried out in the low speed wind-tunnel of the Aeronautics Department. The unusual feature of the bridge under consideration was its composite arch ribs. In the classic suspension bridges, or cable-stayed bridges, the deck is suspended from cables and the stability resolved using the deck alone in the tests. In the case of the proposed bridge, the deck and the supporting arch rib would interact, and each would contribute to the dynamic behaviour of the bridge as a whole. However, because of the differing modes of motion of the parts it was thought that the aerodynamic stability of the complete structure could be determined from tests of section models of each part. Interaction between the parts would tend to reduce motion and increase stability. The size of the wind-tunnel working section usually prohibits testing of complete models at an acceptable scale. The radius of curvature of the arch rib was such that straight sections could be used for the model with very small errors. The separate section models were tested on the three-component balance to determine the steady wind forces on the bridge, which were also compared with predictions using British Standards data, and then on a dynamic mounting to examine their aerodynamic stability. Both the arch rib and the deck had a low speed resonant vibration caused by the natural frequency of the structure matching that of the shedding of vortex pairs from the top and bottom surfaces. The amplitudes of vibration of both were greatly reduced by cutting holes in the webs of the spanwise girders of the deck, and in the side plates of the arch ribs. These holes bled air from the leading edges, and reduced the strength of the vortices. The deck had a divergent pitch oscillation at high speeds, induced by a vortex phenomenon. The speed at which this occurred was increased by about 30% by adding a trapezoidal fairing to the edge of the roadway parapet. This reduced the strength of the upper surface vortex by smoothing the airflow. The low speed instability can be predicted using the Strouhal number for the structure, and amplitudes of vibration can be estimated for a number of damping levels. The pitch instability could only be determined experimentally, and as it will lead to catestrophic failure of the structure, it is essential that the critical speed is well above that likely to be experienced by the prototype. Detail changes have a very important effect on this motion and extrapolation to the full-size prototype must be done with great care. Much more dynamic experimental data are needed from full-size prototypes to allow more confident predictions to be made from model testing

Measurement of the Lifetime of the Metastable 5d\u3csub\u3e3/2\u3c/sub\u3e26d\u3csub\u3e3/2\u3c/sub\u3e, J=0 Autoionizing State of Barium

We report a measurement of the lifetime of the metastable 5d3/226d3/2, J=0 autoionizing state of barium. We have determined the lifetime to be 190(10) ns

Two-Step Stabilization of Autoionizing States

A two-step process using internal conversion and fluorescence to stabilize the 6P3/211d autoionizing state of barium has been observed. The internal conversion produces very highly excited autoionizing Rydberg states, which then emit fluorescence to produce singly excited, bound states. Inclusion of this process should bring calculations closer to agreement with recent measurements of dielectronic recombination

The Influence of Advertising to the Purchase Intention of Mobile Phone in Taiwan

Consumer purchase intention is one of the key factors affecting companies advertising strategy. Advertising is a pervasive influence in our daily lives. It is urged that, to enhance communication and persuasion, marketers should seek a cognitive, affective, brand attitude or behavioral response through the exposure of advertisement. This paper is to study how ways of advertising influence on the purchase intention of Taiwan University students. Each person couldhave different reasons and motifs (preference) in choosing brand of mobile phones. Therefore, it is interesting to explore the influence of advertising to the purchase intention of Taiwan university students. Three questions are asked; How Taiwan university students react to the advertising? What factors influence the purchase intention of Taiwan university students? And what are the students’ reactions to brand attitude

Asthma symptoms in Hispanic children and daily ambient exposures to toxic and criteria air pollutants.

Although acute adverse effects on asthma have been frequently found for the U.S. Environmental Protection Agency's principal criteria air pollutants, there is little epidemiologic information on specific hydrocarbons from toxic emission sources. We conducted a panel study of 22 Hispanic children with asthma who were 10-16 years old and living in a Los Angeles community with high traffic density. Subjects filled out symptom diaries daily for up to 3 months (November 1999 through January 2000). Pollutants included ambient hourly values of ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide and 24-hr values of volatile organic compounds (VOCs), particulate matter with aerodynamic diameter < 10 microm (PM10, and elemental carbon (EC) and organic carbon (OC) PM10 fractions. Asthma symptom severity was regressed on pollutants using generalized estimating equations, and peak expiratory flow (PEF) was regressed on pollutants using mixed models. We found positive associations of symptoms with criteria air pollutants (O3, NO2, SO2, PM10), EC-OC, and VOCs (benzene, ethylbenzene, formaldehyde, acetaldehyde, acetone, 1,3-butadiene, tetrachloroethylene, toluene, m,p-xylene, and o-xylene). Selected adjusted odds ratios for bothersome or more severe asthma symptoms from interquartile range increases in pollutants were, for 1.4 ppb 8-hr NO2, 1.27 [95% confidence interval (CI), 1.05-1.54]; 1.00 ppb benzene, 1.23 (95% CI, 1.02-1.48); 3.16 ppb formaldehyde, 1.37 (95% CI, 1.04-1.80); 37 microg/m3 PM10, 1.45 (95% CI, 1.11-1.90); 2.91 microg/m3 EC, 1.85 (95% CI, 1.11-3.08); and 4.64 microg/m3 OC, 1.88 (95% CI, 1.12-3.17). Two-pollutant models of EC or OC with PM10 showed little change in odds ratios for EC (to 1.83) or OC (to 1.89), but PM10 decreased from 1.45 to 1.0. There were no significant associations with PEF. Findings support the view that air toxins in the pollutant mix from traffic and industrial sources may have adverse effects on asthma in children

Identification of a New Blend of Apple Volatiles Attractive to the Apple Maggot, Rhagoletis pomonella

Solid-phase microextraction (SPME) and gas chromatography coupled with electroantennographic detection (GC-EAD) were used to identify a new blend of volatiles from apples as the key attractants for the apple maggot fly, Rhagoletis pomonella (Walsh). The new five-component blend contains butyl butanoate (10%), propyl hexanoate (4%), butyl hexanoate (37%), hexyl butanoate (44%), and pentyl hexanoate (5%) compared with a previously reported seven-component mix of hexyl acetate (35%), (E)-2-hexen-1-yl acetate (2%), butyl 2-methylbutanoate (8%), propyl hexanoate (12%), hexyl propanoate (5%), butyl hexanoate (28%), and hexyl butanoate (10%). Volatiles from five different varieties of apple elicited reproducible and high EAD responses from R. pomonella antennae to the same five chemicals. In flight-tunnel choice tests involving red sticky spheres with odor sources, the new five-component blend of apple volatiles showed significantly more activity than the previous seven-component blend or the single compound, butyl hexanoate. In a field trial captures with the new five-component blend were better than with butyl hexanoate, which is currently used with commercial apple maggot monitoring sphere

Tomato diseases and insect pests : identification and control

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