A m ethod is prese nted for preparing C'4-l abeled L-ascorbi c acid (vi tamin C) from labeled banum D-gluconate or D-glucose. The process is adapted from t he commercial synthesis of vi tamin C t hrough sorbitol, L-sorbose and potassium di-O-isopropylidene-2kelo-L-guloll.ate. In .th e cyanohydrin . synt hesis of labeled D-glucose, barium D-gluconate is used as an lI1term ed~at~ . Fo: prepanng l...

Compounds found in portland cement are diffi cul t to prepare completely free of carbon diox ide. The difficu lty is further intensified in t he case of calcium aluminate monosulfate by t he instability of t he compound in t he course of its precipi tation from solut ion a nd t he consequent need fo r prepa ring it wi thi~l a limi ted t ime. The co mpound has been preparcd 111 a large qua nt it...

The cosine-fourth-power law states that the irradiance 1 a t any point in the image formed by a photographic lens, in the absence of vignetting, is equal t o Eo cos' {3, where E o is the irradiance at the center of the fi eld , and {3 is the a ngle between the axis of the lens and the conjuga te chief ray in the object space. Although not usua ll y so st a ted , this law in volves th e addition...

The a ppli cation of cer tain power stab ili zation a nd measure men t tec hniqu es to t he problem of attenuation measurement has y ielded a measureme nt syste m wit h a stab ili ty a nd resolu t ion of t he o rder o f 0.0001 decibel. A pract ical a ppli cation fo r t his tech nique was rece nt ly provided in t he calibrat ion of a rotary vane type of varia b le microwave attenu ata I' . In or...

mong the most popular and consequential beliefs of our age is the belief in collective security. Nothing less significant than the legitimacy of the modern state rests on this belief. I will demonstrate that the idea of collective security is a myth that provides no justification for the modern state, and that all security is and must be private. Yet, before coming to the conclusion let me begi...

Historical methods have long been put to use in the making of natural knowledge. In this article, I examine historical by nineteenth-century physicists, focusing on Austrian researcher Ernst Mach particular. argue that applied characteristic then-dominant and philological disciplines his own discipline physics. He construed history as a tool for physicist. On basis study notebooks correspondenc...

T his pap er pr esents t he results of a study of the geomet ric and arit hmetic prope rt ies of t he graph of a simple cellular automaton, considered as a mapping of t he uni t inter val to it self. T he graph provides an examp le of a st rict ly self-similar figur e and exhibits some numeric pr op ert ies relating to Fermat numbers. In ad dit ion an interest ing density resul t is proved: t h...

Cover Story: WMHS 602 Study Abroad, p. 1; Articles: Wastewater Irrigation; p. 5; Irrigation Practices; p. 6; Water-Energy-Food; p. 7; Illegal Tapping oil pipelines; p. 10; The Zapotillo Dam p. 11; Guanajuato Water Gap; p. 12; WHMS News: Recent graduates p. 14; Water in the News: Texas and National News; p. 14; Water for Fun: Crossword Puzzle; p. 15; Seminars schedule; p. 16; Students Organizati...

This paper describes the status of the MIT ATIS system as of February 1992, focusing especially on the changes made to the SUMMIT recognizer. These include context-dependent phonetic modelling, the use of a bigram language model in conjunction with a probabilistic LR parser, and refinements made to the lexicon. Together with the use of a larger training set, these modifications combined to redu...

Complex contact interactions between the robot and its environment (contact between a dextrous hand and a grasped object, contact between an all-terrain vehicle and the terrain, ..) depend on physical properties such as mass, mass distribution, rigidity/elasticity factors, viscosity, and collision forces. Classical geometrical models (representing the spatial properties of an object) are obviou...