A Criticism of Criticism: In Re Meaning

Philosophers and literary critics have long discussed the meaning of words-or, more exactly, whether words themselves have any real meaning. The argument, Mr. Henson suggests, is relevant also to legal criticism. Words about words may generate and perpetuate arguments, but they do not solve problems involving people and things

Development, qualification, and delivery of a hydrogen burnoff igniter

The hydrogen burnoff igniter, a pyrotechnic device used to burn off excess hydrogen gas near the Space Shuttle Main Engine (SSME) nozzle, was designed, fabricated, and qualified. Characteristics of the burnoff igniter include a function time of 8 + or - 2 seconds, a minimum three foot flame length at maximum output, and hot particles projected 15 feet when fired directly into or perpendicular to a 34.5 knot wind. The three foot flame length was considered to be of questionable importance, since the hot particles are the media for igniting the hydrogen. Flame temperature is greater than 1500 F

Skylab atmospheric contamination control

The Skylab contamination removal systems, preflight analysis and testing, and flight results are described. Results indicate that the combination of materials selection, the onboard removal devices, and the offgassing tests proved to be an effective means of controlling spacecraft contaminant levels

A Lost Theorem: Definite Integrals in Asymptotic Setting

We present a simple yet rigorous theory of integration that is based on two axioms rather than on a construction involving Riemann sums. With several examples we demonstrate how to set up integrals in applications of calculus without using Riemann sums. In our axiomatic approach even the proof of the existence of the definite integral (which does use Riemann sums) becomes slightly more elegant than the conventional one. We also discuss an interesting connection between our approach and the history of calculus. The article is written for readers who teach calculus and its applications. It might be accessible to students under a teacher's supervision and suitable for senior projects on calculus, real analysis, or history of mathematics

High spin structures in the A≈40A\approx 40 mass region: from superdeformation to extreme deformation and clusterization (an example of 28^{28}Si)

The search for extremely deformed structures in the yrast and near-yrast region of $^{28}$Si has been performed within the cranked relativistic mean field theory up to spin $I=20\hbar$. The fingerprints of clusterization are seen (well pronounced) in the superdeformed (hyperdeformed) configurations.Comment: 3 pages, 2 figures (note that due to size limitations Fig. 2 has reduced resolution as compared with journal submission), contribution to the proceedings of the 11th International conference on Clustering Aspects of Nuclear Structure and Dynamics, Napoli, May 23-27, 2016, which will be published in Journal of Physics: Conference serie

Physiological Aspects of Genetics

A considerable amount of evidence indicates that desoxyribonucleic acid is capable of duplicating itself, a property also possessed by genes. (By a self-duplicating material, we mean one which plays some essential role in its own production.) Watson & Crick (1) have proposed a new structure for desoxyribonucleic acid which not only takes into account the existing analytical and x-ray diffraction data but also seems capable of explaining the mechanism of duplication. Their model consists of two helical chains coiled around the same axis, the purine and pyrimidine bases on the inside, the phosphate groups on the outside. The chains are held together by hydrogen bonds between the bases, the adenine residues of either chain being bonded specifically to thymine in the other, and similarly guanine to cytosine. The sequence of bases along one chain is not restricted, but once fixed the sequence along the other chain is determined. This complementarity, which is the most novel feature of the structure, suggests that duplication takes place by separation of the two chains, followed by the synthesis of its complement alongside each chain. The model is supported by recent x-ray diffraction studies (2, 3)