Application of full-factorial design for optimization of the moisture determination in wheat flour using infrared scales

We studied the parameters that may affect the analysis of the moisture content in wheat flour using infrared scales. The parameters were studied by one-factor at a time methodology and then, by full-factorial design (2³). The best condition using infrared scales occurred at 120 °C, with a sample weight of 1.5 g and an exposure time to infrared radiation of 6 min. We observed the interaction effect between the three factors studied. The analysis time was 60 times lower than classical method. The optimized method for determination of the moisture content in wheat flour using infrared scales was validated to range between 9 and 17 %.     

THERMAL-STRESS PROBLEMS IN INDUSTRY. 2: TRANSIENT THERMAL STRESSES IN A DISK BRAKE

A general solution is given for the transient thermal stresses in a disk brake caused by constant heat generation on both plane surfaces. The solution rigorously meets the traction-free boundary condition on both the lateral and plane surfaces of the disk. Numerical results for the stress fields are given.     

Transient thermal stresses in a bonded composite hollow circular cylinder under symmetrical temperature distribution

A general treatise for the transient thermal stress problem of a composite circular cylinder made by bonding is described under a symmetrical temperature distribution. Analysis is developed by stress function method by the aid of Laplace transforms. Numerical examples are illustrated for the hollow composite cylinder with several radius-ratios made by the different materials due to transient heating at the internal surface by liquid.     

Thermal stress concentration problem in a plate with a slit

Elliptical coordinates are used for the solution of thermal stress concentration problems at slit-tips by means of the degeneration of an elliptical hole in a square plate. The stress function approach in combination with the point-matching method have been used for the computation of stress concentration factors for various configurations of slits in form of elliptical holes under uniform heat generation.     

THERMAL-STRESS PROBLEMS IN INDUSTRY. 6: TRANSIENT THERMAL STRESSES IN A PLATE DUE TO ROLLING WITH CONSIDERATION OF COUPLING EFFECT

In this paper, the transient thermal-stress problem in a plate subjected to frictional heat generation in rolling ( or welding) is theoretically analyzed with the consideration of the thermomechanical coupling effect. Numerical evaluation is carried out for the temperature distribution, thermal stresses, and thermal deformation in a flat plate heated by linear heat sources which are located symmetrically on both surfaces and which move with constant velocity.     

TRANSIENT THERMAL STRESSES OF A HOLLOW SPHERE DUE TO ROTATING HEAT SOURCE

Abstract

A three-dimensional theoretical treatment for the thermal-stress problems in spherical coordinates is developed. The first part is devoted to the relations of stress components in terms of thermoelastic displacement potential and a harmonic function. Next, a hollow sphere with a rotating heat source is considered as an illustrative example. The numerical calculations are then also carried out and the results shown graphically.     

Thermal stresses and couple-stresses in square cylinder with a circular hole

This article deals with the effect of couple-stresses on thermal stress distribution in a square cylinder with a central circular hole under steady state temperature distribution. The analysis is developed by the point-matching technique.From our calculation, it may be concluded that stress concentration around a circular hole, taking couple-stress into account, results in lower values than those accepted heretofore.     

The effects of dynamical treatment of thermal stresses on a circular region due to continuous point heat source

The investigation referring to the effects of inertia term on the plane transient thermal stress problems are treated for a solid circular cylinder under a continuous point heat source.