Ring loading of a long, thin, circular cylindrical shell enclosing a soft, solid core: A recalculation by the love function method of elasticity.

The problem is solved using the Love function and Flügge shell theory. Numerical work has been done with a computer for various values of shell geometry parameters and elastic constants.

A weighted mean square method of linearization in non-linear oscillations

The paper deals with a linearization technique in non-linear oscillations for systems which are governed by second-order non-linear ordinary differential equations. The method is based on approximation of the non-linear function by a linear function such that the error is least in the weighted mean square sense. The method has been applied to cubic, sine, hyperbolic sine, and odd polynomial types of non-linearities and the results obtained are more accurate than those given by existing linearization methods.

A new method of producing local enhancement of buoyancy in liquid flows

We describe here a novel method of generating large volumetric heating in a liquid. The method uses the principle of ohmic heating of the liquid, rendered electrically conducting by suitable additives if necessary. Electrolysis is prevented by the use of high frequency alternating voltage and chemically treated electrodes. The technique is demonstrated by producing substantial heating in an initially neutral jet of water. Simple flow visualisation studies, made by adding dye to the jet, show marked changes in the growth and development of the jet with heat addition.

Continuous-cooling method of specific heat measurement in the temperature range 100-300 K

The authors have developed a simple continuous-cooling method to determine specific heat of liquids and solids in the temperature range 100-300 K. The technique employs very simple instrumentation and continuously records the sample temperature as it cools to the bath temperature through a calibrated heat link. They have obtained specific heat values which agree with the reported data to within 3% for the samples investigated. This method also facilitates easy detection of abrupt changes in specific heat, as demonstrated in the observation of glass transition in some organic glass-forming systems. The method is sensitive to the study of relaxing heat capacity in supercooled liquids.

Contraception in Namibia : usage, methods and the impact of education

Användningen av preventivmedel har blivit en allt viktigare fraga i utvecklingsländerna idag, speciellt i Namibia dar fruktsamheten och HIV-prevalensen är höga. Kondomen är det enda allmänt tillgängliga preventivmedlet som skyddar mot könssjukdomar, medan ocksä injektioner, p-piller och andrà metoder kan användas för att förhindra graviditet. Användningen av preventivmedel har upptäckts korrelera med vissa sociodemografiska faktorer, bland annat utbildningsnivå och förmögenhet. Malet med denna undersökning var att studera användningen av preventivmedel, avsikter att använda preventivmedel samt kunskap om HIV/AIDS och andra könssjukdomar bland kvinnor i Namibia. Detta gjordes frän ett historiskt perspektiv genom att studerà användningsmönster frän 1990 till slutet av 2000-talet. Dessutom undersöktes sociodemografiska faktorers, speciellt utbildningens, inverkan på användningen av preventivmedel, likasä sambandet mellan skolningsnivå och preventivmedelsanvändning pä regionnivå. Undersökningen gjordes utgäende frän statistiska Namibia Demographic and Health Survey -material samlade 1992, 2000 och 2006-2007. Prevalenser och användningen av specifika metoder studerades skilt för olika bakgrundsvariabler 1992, 2000 och 2006-2007, och enligt utbildningsnivå och region är 2006-2007. Utbildning mattes skilt pä individ- och aggregatnivå. Sambandet mellan preventivmedelsanvändning och utbildning undersöktes med hjälp av logistisk regression, i vilken sociodemografiska bakgrundsfaktorer kontrollerades i sex modeller. Resultaten visade att användningen av preventivmedel har fördubblats sedan början av 1990-talet. Skillnader mellan kvinnor med olika utbildningsnivåer existerade redan i början av 1990-talet, likaså mellan olika yrkesgrupper. Undersökningen visade att högre utbildning ökar på reventivmedelsanvändningen, också då sociodemografisk bakgrundfaktorer, även utbildning och användning av preventivmedel på aggregatnivå, kontrollerades. Undersökningen antyder att utbildning på aggregatnivå inte ensam påverkar användningen av preventivmedel hos en individ. De sistnämnda resultaten var dock inte statistiskt signifikanta och kan inte generaliseras över namibiska kvinnor i allmänhet.

Passive immunization with an antibody to the beta-subunit of ovine luteinizing hormone as a method of early abortion--a feasibility study in monkeys (Macaca radiata)

Antiserum to the beta-subunit of ovine luteinizing hormone (oLH-beta) raised in monkeys (Macaca radiata) has been tested by a variety of criteria both in vivo and in vitro to establish its ability to neutralize oLH, hLH, and human chorionic gonadotropin (hCG). Passive administration of this antiserum caused inhibition of ovulation and termination of pregnancy in recipient monkeys as indicated by premature vaginal bleeding and a significant reduction in serum progesterone and estrogen levels. The results suggest that antiserum raised in monkeys against oLH-beta can neutralize monkey LH as well as monkey CG.

On Application Of The Method Of Kinetic Invariants To The Description Of Dissolution Accompanied By A Chemical Reaction

The dissolution, accompanied by chemical reaction, of monodisperse solid particles has been analysed. The resulting model, which accounts for the variation of mass transfer coefficient with the size of the dissolving particles, yields an approximate analytical form of a kinetic function. Rigorous numerical and approximate analytical solutions have been obtained for the governing system of nonlinear ordinary differential equations. The transient nature of the dissolution process as well as the accuracy of the analytical solution is brought out by the rigorous numerical solution. The analytical solution is fairly accurate for the major part of the range of operational times encountered in practice.

An efficient marching algorithm for waterhammer analysis by the method of characteristics

A new fast and efficient marching algorithm is introduced to solve the basic quasilinear, hyperbolic partial differential equations describing unsteady, flow in conduits by the method of characteristics. The details of the marching method are presented with an illustration of the waterhammer problem in a simple piping system both for friction and frictionless cases. It is shown that for the same accuracy the new marching method requires fewer computational steps, less computer memory and time.

Method of Analysis if Uniaxial Deformation Data

A comprehensive scheme for analysing uniaxial deformation data, taking into account the finite stiffness of the testing machine is presented. Equations relevant to tension and stress relaxation tests carried out under cross head speed control, and to creep testing under constant load, are described. For the first two cases, the implications of not using gauge length extensometry but relying upon cross head displacement for inferring specimen extension, and the role of uncertainty in machine stiffness are also examined. The final section touches upon the extension of the present scheme to account for specimen anelasticity.

Time-domain-finite-wave analysis of the engine exhaust system by means of the stationary-frame method of characteristics. Part I. Theory

Time-domain-finite-wave analysis of the engine exhaust system is usually done using the method of characteristics. This makes use of either the moving frame method, or the stationary frame method. The stationary frame method is more convenient than its counterpart inasmuch as it avoids the tedium of graphical computations. In this paper (part I), the stationary-frame computational scheme along with the boundary conditions has been implemented. The analysis of a uniform tube, cavity-pipe junction including the engine and the radiation ends, and also the simple area discontinuities has been presented. The analysis has been done accounting for wall friction and heat-transfer for a one-dimensional unsteady flow. In the process, a few inconsistencies in the formulations reported in the literature have been pointed out and corrected. In the accompanying paper (part II) results obtained from the simulation are shown to be in good agreement with the experimental observations.

Time-domain-finite-wave analysis of the engine exhaust system by means of the stationary-frame method of characteristics. Part II. Computed results and experimental corroboration thereof

Time-domain-finite-wave analysis of engine exhaust systems is usually carried out by means of the method of characteristics. The theory and the computational details of the stationary-frame method have been worked out in the accompanying paper (part I). In this paper (part II), typical computed results are given and discussed. A setup designed for experimental corroboration is described. The results obtained from the simulation are found to be in good agreement with experimental observations.