Rigidity Modulus of Lead Single Crystals (Abstract)

The isothermal rigidity modulus has been measured for lead crystals of various orientations. The reciprocal bending-torsion effect and its influence on the measurement are considered

Scattering of Electromagnetic Waves in the Troposphere and the Use of This Technique For Communications

This article is an introduction to the subject of tropospheric scatter propagation for the non-specialist. It opens with a review of various modes of propagation which may exist in a non-turbulent atmosphere, such as diffraction and ionospheric reflection. The scattering of energy in a turbulent medium is then examined, and statistical methods are introduced to describe the resultant field. Special characteristics of the signal are discussed, such as variation with distance, climatic effects, frequency dependence, fading, bandwidth, and noise level. The paper concludes with a description of methods and equipment employed in the design of a communication system operating over a distance in the range of 100 to 500 miles. It is concluded that tropospheric scatter terminals are large and costly, but that under some circumstances such a system has economic advantages over a line-of-sight relay system and can furnish comparable quality and reliability

Study of the Remediation of Deficiencies in Auditory Perception

Author Institution: Kent City Schools; Department of Counseling and Special Education, University of AkronThe screening of 243 students from 10 kindergarten classes resulted in the identification of 39 children with perceptual deficiencies in the auditory channel. Auditory training procedures dictated by Lerner's definition of auditory perception were introduced into 5 kindergarten classes. Five no-treatment classes were included as control groups. Effects of the training program reported for these 39 subjects indicated growth at the meaningful level of language usage and improvement in the ability to analyze words. The effects of the auditory training program on reading readiness and self-concept were encouraging

Semiprime locally (-1, 1) rings with minimal condition

Let L be a left ideal of a right alternative ring A with characteristic ::/=2. If L is maximal and nil, then L is a two-sided ideal. If L is minimal, then it is either a two-sided ideal, or the ideal it generates is contained in the right nucleus of A. In particular, if A is prime, then a minimal left ideal of A must be a two-sided ideal. Let A be a semiprime locally (-1, 1) ring with characteristic ::1=2, 3. Then A is isomorphic to a subdirect sum of an alternative ring, a strong (-1, 1) ring, and a locally (-1, 1) ring with a certain property, where each of these three rings is likewise semiprime with characteristic ::/=2, 3, and where each satisfies any minimal condition satisfied by A. In particular, when A satisfies the minimal condition on two-sided ideals, then A satisfies certain additional identities; and when A satisfies the minimal condition on right ideals, then it must be alternative