NASA Langley Research Center HBCU/OMU program: 1990 student support survey

The results of a survey of students who are receiving support through the Historically Black Colleges and Universities and Other Minority Universities are given. Information is given on the race, sex, ethnic distribution, grade point average distribution, and target degree distribution

Recognition as a Measure of Learning from Television Commercials.

This is the published version. Copyright 1983 American Marketing Association.Recognition has not received extensive acceptance by practitioners as a response variable for learning of television commercials. The authors review some of the distinctions between recoil and recognition, and some of the problems associated with each. In a laboratory experiment they developed and tested a measure of recognition useful for low involvement situations in which a recall level of learning may not be necessary. Data and implications about the usefulness and limitations of the measure are presented

Predation of Neozygites tanajoae-infected cassava green mites by the predatory mite, Typhlodromalus aripo (Acari: Phytoseiidae)

Typhlodromalus aripo is the most successful of the Neotropical predatory mites released for the classical biological control of the cassava green mite, Mononychellus tanajoa, in Africa. A few isolates of the entomopthoralean fungus, Neozygites tanajoae, which causes epizootics in M. tanajoa populations in Brazil, were imported to be released in Africa for the control of M. tanajoa. The present study evaluated the feeding preference of T. aripo for M. tanajoa infected by N. tanajoae in a preliminary attempt to determine the interaction between the two biological control agents. The feeding preferences of normal and starved, for 24 and 48 h, T. aripo for the healthy M. tanajoa and for those exposed to N. tanajoe were compared in choice and no choice tests. In general, T. aripo consumed significant quantities of infected M. tanajoa along with the healthy ones. Although, they appeared to have a slight preference for healthy M. tanajoa, significant difference (P < 0.05) was seen only in a no choice test when the predators that were starved for 24 h were used. The consumption of pathogen-infected pest mites by the predatory mites can reduce the effectiveness of the microbial control agent

A Comparison Between Growth Morphology of Eutectic Cells/Dendrites and Single-Phase Cells/Dendrites

Directionally solidified (DS) intermetallic and ceramicbased eutectic alloys with an in-situ composite microstructure microstructure containing finely distributed, long aspect ratio, fiber, or plate reinforcements are being seriously examined for several advanced aero-propulsion applications. In designing these alloys, additional solutes need to be added to the base eutectic composition in order to improve their high temperature strength, and provide for adequate toughness and resistance to environmental degradation. Solute addition, however, promotes instability at the planar liquid-solid interface resulting in the formation of two-phase eutectic “colonies.”[1–4] Because morphology of eutectic colonies is very similar to the single-phase cells and dendrites, the stability analysis of Mullins and Sekerka[5] has been extended to describe their formation.[6,7,8] Onset of their formation shows a good agreement with this approach;[9] however, unlike the single-phase cells and dendrites, there is limited examination of their growth speed dependence of spacing, morphology, and spatial distribution.[4,10–11] The purpose of this study is to compare the growth speed dependence of the morphology, spacing, and spatial distribution of eutectic cells and dendrites with that for the single-phase cells and dendrites

On-line analysis of ash containing slurries

The ash content of coal suspended in a slurry is determined by bombarding a sample of the slurry flowing past a window of a measuring chamber with radiation from an annular nucleonic source, such as Cm-244, for emitting radiation within the range of about 7 to about 30 KeV and causing the sample to emit both backscat- tered and iron fluorescent x-rays. These x-rays are detected by a radiation detector which produces first and second electrical signals representative of the intensity of each. The density of the sample flowing from the measuring chamber is measured, such as by a nucelonic density gauge, to produce an electrical signal representative of the density and the ash content is determined from the detected intensities of the backscattered and iron fluorescent x-rays and the sample density.https://digitalcommons.mtu.edu/patents/1093/thumbnail.jp

Cell/Dendrite Distribution in Directionally Solidified Hypoeutectic Pb-Sb Alloys

The alloys Pb-2.2 wt pet Sb and Pb-5.8 wt pet Sb were directionally solidified with three different thermal gradients of 40, 86, and 140 K cm(-1) at growth rates ranging from 0.6 to 30 mu m s(-1). A Gaussian peak amplitude analysis of the cell/dendrite spacing distribution shows a distinct peak corresponding to the nearest neighbors. The peaks corresponding to the second and the third nearest neighbor spacings are also brought out by this technique. The ratios of the second to the first nearest neighbor spacings and that of the third to the first neighbor spacings are 1.85 +/-: 0.11 and 2.70 +/- 0.25, respectively. This indicates that the cells and dendrites both have a hexagonal distribution with a significant amount of superimposed noise. This is also confirmed by the frequency distribution of their number of nearest neighbors\u27 (coordination number)

Cellular/Dendritic Array Tip Morphology During Directional Solidification of Pb-5.8 Wt Pct Sb Alloy

Cellular/dendritic array tip morphology has been examined in directionally solidified and quenched Pb-5.8 wt pet Sb alloy by a serial sectioning and three-dimensional image reconstruction technique. There is a large scatter in the tip radius, the nearest neighbor spacing, and the mushy zone length, even among the immediately neighboring cells and dendrites. This scatter may be caused by the natural convection (in the mushy zone and in the bulk melt at the array tip), which also produces macrosegregation along the length of the directionally solidified samples. Even in the presence of convection, however, the tip radii are observed to be approximately proportional to the square of the primary spacings, and the radii are in a good quantitative agreement with the predictions from the model due to Hunt-Lu