Since the fluid flow, heat transfer, and the resulting weld properties are significantly affected by interfacial tension driven flow, the variation of interfacial tension in dilute binary solutions is studied as a function of both composition and temperature. Entropy and enthalpy of adsorption of surface active components such as oxygen, sulfur, selenium, and tellurium in Fe-O, Fe-S, Fe-Se, Cu-O, Cu-S, Cu-Se, Cu-Te, Ag-O, and Sn-Te systems were calculated from the analysis of the published data on interfacial tension of these systems. For these calculations, a formalism based on the combination of Gibbs and Langmuir adsorption isotherms was used. Interfacial tensions in Cr-O, Co-S, and Ni-S systems, where the data are scarce, were predicted by using certain approximations. The computed values were found to be in reasonable agreement with the data available in the literature. Temperature coefficients of interfacial tensions were calculated for several binary systems. It was demonstrated that in dilute solutions, the temperature coefficient of interfacial tension is strongly influenced by the heat of adsorption which, in turn, is influenced by the difference in electronegativity between the solute and solvent ions.

Surface tension of binary metal—surface active solute systems under conditions relevant to welding metallurgy

The invention relates to gel-coated microcapsules which have improved mechanical stress- and flame-resistance. A method for making the gel coated microcapsules is also provided. Phase change materials can be included in the microcapsules to provide thermal control in a wide variety of environments.

Gel-coated microcapsules

An instrument employs a projector which projects a moving pattern of heat onto a test object. An exemplary pattern is formed of bars or lines of infrared radiation separated by unheated areas, or areas of shadow. An infrared camera which is not sensitive to the wavelength of the projected light is used to detect the heat emitted by the test object. The projected bands of thermal radiation heat the surface of the test object. Some of the energy in the form of heat sinks into the structure, while some of the heat energy flows laterally from the heated band to the unheated bands between the projected bands. The lateral flow of heat between bands is resisted by cracks in the surface. This resistance causes heat energy to build up on one side of each crack. The downward flow of heat energy is resisted by less conductive material such as a debonding between layers which traps the heat, causing it to build up laterally. Thus, flaws caused by cracks normal to the surface and delaminations or cracks parallel to the surface may be detected by the same device.

Structure analysis method using time-varying thermal signal

The surface tensions of liquid Fe, Co, Ni, Cu, Ag, Zn, Pb, Cd, and Sn have been measured by the sessile droplet method and/or the levitated droplet method over wide ranges of temperature. The values of surface tension obtained by the levitated droplet method have always been found to be higher than those measured by the sessile droplet method, a result which is attributed to decreased droplet contamination with the containerless levitation method. Negative temperature coefficients of surface tension have been obtained for all of the metals investigated in this work. Based on a literature survey of the available experimental data, it is shown that the values of both surface tension and the temperature coefficient are influenced in a systematic manner by the presence of surface active impurities. On this basis, positive values of the temperature coefficient of surface tension for liquid Zn and Cd found in the literature may be explained in terms of impurity effects which tend to be particularly pronounced in volatile metals.

The temperature coefficient of the surface tension of pure liquid metals

Disclosed herein is a system for generating energy, comprising a first heat exchanger in communication with a first heat source; wherein the first heat exchanger contacts a transfer fluid that comprises a working fluid and an associating composition; and a first energy conversion device comprising a moving surface, wherein the first heat exchanger is in communication with the moveable surface of the first energy conversion device; and wherein a dissociation of the transfer fluid in the first heat exchanger generates a vapor of the working fluid that contacts the moving surface of the first energy conversion device.

Method and system for thermochemical heat energy storage and recovery

A method of storing energy at ambient temperature and recovering same at an elevated temperature which comprises decomposition of a chemical compound at high temperature with a decomposition product being used to form another compound at low temperature. Upon regeneration of the decomposition product from the other compound there is a release of the originally absorbed high temperature thermal energy.

Chemical storage of energy

Thermal degradation under vacuum, as measured by weight loss of polymer, has been studied for a variety of polymers and composites. Small-sample (∼10 mg) TGA studies have been made on polymeric materials. Isothermal studies, at much lower temperatures, have been made on the same materials of much larger size and weight (4–6 g). Comparison of the results shows that TGA can accurately predict the isothermal kinetics.

Prediction of polymer degradation kinetics at moderate temperatures from tga measurements

An infrared scene projector has a cathode ray tube with a display screen coated with a luminescent phosphor material that produces radiation in the infrared spectrum when excited by the electron beam. The desired screen images are generated electronically, the screen is scanned by the cathode ray beam, and the intensity of the beam is modulated by the signal from the image generator.

Infrared scene projector

The present invention resides in a white thermal control surface resistant to darkening due to exposure to X-rays and ultraviolet radiation. The surface comprises a substrate and a ceramic zirconium orthosilicate coating on said substrate. The zirconium orthosilicate coating is obtained by plasma-spray applying particles of zirconium orthosilicate onto the substrate. The particles of zirconium orthosilicate are doped with an oxide of a +3 valent metal. The metal ions of said +3 valent metal oxide are dispersed substantially uniformly throughout said particles.

Harold A. Papazian

Papers

Chemical storage of energy

Prediction of polymer degradation kinetics at moderate temperatures from tga measurements

Infrared scene projector

White thermal control surfaces

Calculation of surface tension temperature coefficients