Application of magnitude estimation scaling to the assessment of subjective loudness response to simulated sonic booms

A laboratory study was conducted for the following reasons: (1) to investigate the application of magnitude estimation scaling for evaluating the subjective loudness of sonic booms; and (2) to compare the relative merits of magnitude estimation and numerical category scaling for sonic boom loudness evaluation. The study was conducted in the NASA LeRC's sonic boom simulator and used a total of 80 test subjects (48 for magnitude estimation and 32 for numerical category scaling). Results demonstrated that magnitude estimation was a practical and effective method for quantifying subjective loudness of sonic booms. When using magnitude estimation, the subjects made valid and consistent ratio judgments of sonic boom loudness irrespective of the frequency of presentation of the standard stimulus. Presentation of the standard as every fourth stimulus was preferred by the subjects and is recommended as the standard presentation frequency to be used in future tests

A Study of the Administrators\u27 Opinions of the Difficulties Experienced by Beginning Teachers in Selected Negro High Schools in Texas, 1949-50

It was the purpose of this study (1) to discover the specific problems of beginning teachers as reported by their supervisors; (2) to seek to determine how the supervisor helps with these difficulties; (3) to attempt to find out if the beginning teacher seeks the aid of the supervisor in attempting to overcome these difficulties; and (4) to find out what quality supervisors feel that a beginning teacher should possess in order to be successful. It was felt that the major purposes of this investigation could be realized if the answers to the following questions could be found: What are the problems experienced in the classroom by beginning teachers? What type of relationship exists between these teachers and their co-workers? What difficulties did the beginning teachers have in adjusting themselves to community life? How soon after the beginning teachers started teaching did their supervisors feel it necessary to give them supervision? To what extent will the beginning teacher seek supervisory assistance? What professional journals do these supervisors provide to aid the teachers in improving instruction? What is the most desirable quality that supervisors feel that beginning teachers should possess in order to be successful? The study was limited to the difficulties encountered during the first two years of teaching because related studies and writers in the field seem to indicate that two years is the commonly recognized period that is called beginning teaching

Marshall University Music Department Presents a Faculty Recital, Flutes Past and Present, Wendell Dobbs, flutes, Wendell Dobbs, flutes

https://mds.marshall.edu/music_perf/1577/thumbnail.jp

NERVA irradiation program. GTR 23, volume 1: Combined effects of reactor radiation and cryogenic temperature on NERVA structural materials

Specimens fabricated from structural materials that were candidates for certain NERVA applications were irradiated in liquid nitrogen (LN2), liquid hydrogen (LH2), water, and air. The specimens irradiated in LN2 were stored in LN2 and finally tested in LN2, or at some higher temperature in a few instances. The specimens irradiated in LH2 underwent an unplanned warmup while in storage so this portion of the test was lost; some specimens were tested in LN2 but none were tested in LH2. The Ground Test Reactor was the radiation source. The test specimens consisted mainly of tensile and fracture toughness specimens of several different materials, but other types of specimens such as tear, flexure, springs, and lubricant were also irradiated. Materials tested include Hastelloy X, Al, Ni steel, steel, Be, ZrC, Ti-6Al-4V, CuB, and Ti-5Al-2.5Sn

Theory of imaging a photonic crystal with transmission near-field optical microscopy

While near-field scanning optical microscopy (NSOM) can provide optical images with resolution much better than the diffraction limit, analysis and interpretation of these images is often difficult. We present a theory of imaging with transmission NSOM that includes the effects of tip field, tip/sample coupling, light propagation through the sample and light collection. We apply this theory to analyze experimental NSOM images of a nanochannel glass (NCG) array obtained in transmission mode. The NCG is a triangular array of dielectric rods in a dielectric glass matrix with a two-dimensional photonic band structure. We determine the modes for the NCG photonic crystal and simulate the observed data. The calculations show large contrast at low numerical aperture (NA) of the collection optics and detailed structure at high NA consistent with the observed images. We present calculations as a function of NA to identify how the NCG photonic modes contribute to and determine the spatial structure in these images. Calculations are presented as a function of tip/sample position, sample index contrast and geometry, and aperture size to identify the factors that determine image formation with transmission NSOM in this experiment.Comment: 28 pages of ReVTex, 14 ps figures, submitted to Phys. Rev.

Morphology of Three Imported Aphthona Flea Beetles Used as Biological Control Agents of Leafy Spurge

The following morphological study of the three imported Aphtona flea beetles supplies a detailed description of selected structures that will distinguish each of the three imported species and will separate them from a common native fle beetle (Glyptina atriventris) found at South Dakota release sites