Activity coefficients of aqueous methanol solutions

The methods employed in determination of vapor pressures of liquids have been reviewed. The gas saturation method has been used to determine the partial and total vapor pressures of water-methanol solutions at 0°C. From the vapor pressure data thus obtained, activities and activity coefficients of water and methanol have been calculated and the results have been plotted against the mole fraction composition. The data obtained showed a positive deviation from Raoult\u27 s law for the solution. The activity coefficient curves have been analyzed and found to satisfy the requirements of the Duhem-Margules equation. These curves have also been fitted with an empirical equation which has made possible extrapolation of the curves to infinite dilution. A discrepancy between the data obtained and the data for higher temperatures has also been discussed

Some synchrotron produced radioactivities of tantalum

X-ray irradiation of wolfram by a synchrotron beam have produced three radioactive isotopes of tantalum with half-lives of 48 m. (TA-185), 8.0 hr. (TA-180) and 6.0d (TA-183) Characteristics of the activities have been studied by absorption and coincidence measurements. Separated W-182 was used for the identification of the TA-180. Relative yields of the three isotopes were measured for beam energies of 30 Mev. and 68 Mev. In addition, the yields for 68 Mev. have been compared to the yield of the reaction C-12(y,n) C-11. TA-180 can not form by a (y, p) reaction; however its yield was comparable to the yield of isotopes formed by such a reaction

Calculation of acid dissociation constants

A computational method has been developed for the determination of dissociation constants of acids (and bases). The method is applicable to mono or polybasic acids and, in certain cases, to mixtures of acids. A least-squares treatment is employed, and no simplifying assumptions are made in any of the equations or factors involved. All the available data are utilized, and provision is made for including or calculating activity coefficients. Utilization of the method requires a medium to large size digital computer

High specific radioactivites of cobalt, platinum, and iridium from photonuclear reactions

The attainment of high specific activities is an important requirement for the detect i on and utilization of radioactivities produced by photonuclear reactions. If an element different from the target element is produced suitable chemical procedures for the separation of the radioactive atoms from the target atoms can usually be found. However, finding rapid and efficient methods for separating isotopes of the target element formed by the (y,n) reaction presents a more difficult problem. To facilitate the study of the properties of cobalt and platinum actiities produced in the synchrotron by (y,n) reactions, an attempt was made to find complexes of these elements which would undergo Szilard-Chalmers type reactions. A portion of the study was also devoted to the investigation of the activities formed by photonuclear reactions in platinum when PtCl-4.xH-2O is irradiated in the x-ray beam of the synchrotron

The kinetics of the hydrogen peroxide oxidation of selenious acid

The rates of disappearance of selenious acid and hydrogen peroxide have been measured in aqueous acidic solutions containing the two species. Temperature variation of these rates has been observed between 67.7°C and 82.3°C

Iodato-silver complexing equilibria

Solubilities of silver iodate in aqueous solutions containing various concentrations of lithium iodate have been measured for 25.0°C., 35.0°C. and 50.0°C. by means of an improved radioassay technique for silver activity. They have also been measured for the same temperatures in aqueous solutions containing various proportions of lithium iodate and lithium perchlorate. In the latter experiments, the ionic strengths of all equilibrium solutions were fixed at a value of 1.00 M

Kinetics of chloride exchange in aqueous chloride-tetrachloroplatinate (II) system

The investigation described in this thesis has included a study of the kinetics of the exchange of chlorine between chloride and tetrachloroplatinate (II) in aqueous solution. As the case in any exchange study it has been necessary to develop a radioactive tracer technique and separation procedure so that the extent of the exchange could be ascertained. By the determination of the extent of exchange as a function of time, the dependence of the rate of exchange upon a number of concentration variables was demonstrated. It was to be expected that the experimental exchange rate law would elucidate features of the mechanism of the process and the species which were involved

Solubility of the rare earth oxalates and complex ion formation in oxalate solution II. Neodynium and cerium (III)

Previous studies with ytterbium in oxalate solutions have demonstrated that the determination of concentrations by radioassay would permit the evaluation of equilibrium constants for the system. The present paper describes results of similar experiments with neodymium and cerium. Since the lighter rare earths have greater ionic radii, it was expected that the degree of complexing would be less and a lower solubility in oxalate would result. The data presented in this paper for neodymium and cerium confirmed the lower solubility but indicated that the complexes were not substantially weaker. The behavior of cerium was markedly different from that of ytterbium and neodymium in that definite evidence was found for the formation of a trioxalate complex

Non-linear Pattern Matching with Backtracking for Non-free Data Types

Non-free data types are data types whose data have no canonical forms. For example, multisets are non-free data types because the multiset $\{a,b,b\}$ has two other equivalent but literally different forms $\{b,a,b\}$ and $\{b,b,a\}$. Pattern matching is known to provide a handy tool set to treat such data types. Although many studies on pattern matching and implementations for practical programming languages have been proposed so far, we observe that none of these studies satisfy all the criteria of practical pattern matching, which are as follows: i) efficiency of the backtracking algorithm for non-linear patterns, ii) extensibility of matching process, and iii) polymorphism in patterns. This paper aims to design a new pattern-matching-oriented programming language that satisfies all the above three criteria. The proposed language features clean Scheme-like syntax and efficient and extensible pattern matching semantics. This programming language is especially useful for the processing of complex non-free data types that not only include multisets and sets but also graphs and symbolic mathematical expressions. We discuss the importance of our criteria of practical pattern matching and how our language design naturally arises from the criteria. The proposed language has been already implemented and open-sourced as the Egison programming language