Thermodynamic treamnts of the CaO-SiO2 system

Thermodynamic data for heat capacity, enthalpy, and activity in the CaO-SiO₂ system have been analyzed using the Redlich-Kister formalism with up to six terms. This system shows both liquid-liquid immiscibility and large negative deviations from ideality due to a strong acid base interaction. We have found it necessary to use separate power series treatments for the acidic and basic regions. A number of different mathematical approaches have been previously used for this system, all giving reasonable calculated phase diagrams. Comparisons of the various treatments show major differences in the enthalpy and free energy of mixing. The known thermodynamic properties of CaSiO₃ and Ca₂SiO₄ provide a more reliable test of the accuracy of computer treatments than does the shape of the calculated phase diagram.     

A parametric design study of solar ponds

The salt stratified solar pond is found to be a reliable solar collector and storage system. This paper discusses the effect of varying certain design parameters on pond steady-state temperatures. These significant parameters are sizing parameters—pond surface area and depth of the pond; operating parameters—storage volume and the heat extraction fraction; and geo-climatic parameters3s?olar radiation, water table depth and upper convective zone thickness. Studies indicate that there is an optimum depth and storage volume of the pond for each application in terms of temperature and heat load desired.     

The polyuronides: their molecular architecture

The polyuronides (uronic acid containing polymers) are considered for the first time as a coherent group. Until now the dearth of X-ray diffraction data resulted in many questions of polyuronide structure and conformation remaining unasked. The recent success in crystallizing the polyuronides is illustrated with X-ray diffraction patterns of hyaluronic acid, dermatan and chondroitin sulphates, heparan sulphate and heparin. The influence of the chemical structure, the glycosidic linkages and the charged substituents on the molecular conformations is considered together with the marked association with water which these molecules display. Computer-drawn projections of plausible molecular conformations are shown.     

Polarized infrared spectra of crystalline glycosaminoglycans

Polarized infrared spectra have been recorded for oriented, crystalline specimens of hyaluronates, chondroitin 4-sulfate and 6-sulfate, dermatan sulfate, and a cartilage proteoglycan, having different known chain conformations as determined by X-ray diffraction. The dichroism data for the vibrational modes of the amide and carboxyl groups have been interpreted with respect to the particular molecular structures.     

A Pilot Clinical PEP Monitor

An instrument for the continuous measurement of pre-ejection period (PEP) in the human fetus using Doppler ultrasound is presented. An important feature of the instrument is its ability to track the continuously changing location of the reflections. The design includes a recently developed nonlinear filtering technique that is quite insensitive both to the large amounts of noise of biologic origin and the random dynamic amplitude variations. The efficiency of the scheme is illustrated by simulated and clinical tests.     

Monoton finite element matrices and their computed condition numbers

Certain finite element stiffness matrices appearing in the discretization of second order problems possess positive inverses (are monoton). Some classical theorems concerning such positive matrices are expediently evoked to compute numerical lower and upper bounds of any desired closeness on the maximum and spectral condition numbers of these matrices.     

Community mental health services for the Spanish-speaking/surnamed population.

Discusses reasons why the Spanish-speaking/surnamed population receives mental health care of a different kind, of a lower quality, and in lesser proportions than any other ethnically identifiable population. This underutilization cannot be explained because of the substitution of either folk medicine or faith healing. Race and social class of the therapist seem to affect the patient's response to treatment, and middle-class values are often misapplied to lower-class patients. 3 models for improved services to this population are described: a professional adaptation model, a family adaptation model, and a barrio service center model. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A gradient computational procedure for the solution of large problems arising from the finite element discretization method

A computational procedure based on gradient iterative techniques is proposed for the solution of large problems to which the finite element method is applicable. In linear problems the procedure can be used either for solving the set of algebraic equations or for the complete inversion of the matrix of coefficients. Special attention is focused on the practical aspects of the procedure concerning its realization on the digital computer.