摘要:
According to the method for rastering half-tone images, grey values of the image are reproduced by modifying the structure density of a base raster structure selected according to the form. The attribution of the field of grey values of the half-tone image to the raster structural density reproducing said field of grey values may be fixed appropriately. In a phototechnical version of the method (Fig. 1), there is obtained a selected base raster structure (1) and from the latter enlarged raster structures are produced as negative films (9, 11). From the image to be rastered (13), there is produced, as negative films, a same number of extracts of tone values (20, 22), each of them reproducing a predetermined field of grey values of the half-tone image, fixed by means of the exposure time. The extracts of tone values (22, 20) are exposed on a support (24), with the raster structures (9, 11) of the series to which they are attributed. The support then reproduces the rastered image in a form such that the grey values portions determined by the extract of tone value are locally reproduced by the raster structural density attributed to them. There are a plurality of alternatives in the photographic technics and in the laser technics, implementing said method, which are appropriate for the rastering of half-tone images, for the production of half-tone blocks and for printing reproduction supports with images thus rastered.
摘要:
A process is disclosed for reducing the carbon content of a melt (8,36) of metal or metal alloy, carbon, and at least one oxide forming metallic alloying element from an initial value of about .1 wt % carbon to a final value of not less than about .003 wt % carbon. The process consists of contacting the melt (8,36) with a reactive oxide (18,40) of the metallic alloying element and simultaneously stirring the melt with an inert gas.
摘要:
A container for liquids, semi-liquids, powders and similar flowable fluids comprises a substantially airtight body (10) for storing the fluid, a means for varying the pressure of gas above the level of the fluid in the body of the container, e.g. resilient flexible container walls such as a squeeze bottle, an air pocket structure (22) disposed at the lower end of the container, and in free fluid communication with the body of the container so as to allow entry of fluid from the body of the container into the air pocket structure. Air resides in the air pocket structure when the container is disposed with its lower end downwardly. An outlet passageway (20) has an upper end (24) which communicates near the top of the air pocket structure to be disposed in air retained in the air pocket and a lower end open to atmosphere exteriorly of the container and the air pocket. Such a container holds liquids therein without dripping. To discharge the liquid or other fluid the pressure on the body (10) is increased, so as to cause liquid to rise through the air pocket (22) into the outlet passageway (20), and to issue therefrom. Upon release of the applied pressure, air is sucked back in through the passageway so as to have a cleaning effect thereon. The structure allows storage of liquid ready for dispensing, but without risk of leakage or dripping, even when exposed to fluctuations in temperature of considerable magnitude.
摘要:
(57) The present direct invention is directed to a sealing glass composite comprising a low melting point sealing glass matrix mixed with a particulate additive to increase the effective coefficient of thermal expansion of the resulting sealing glass composite. The sealing glass matrix is in the lead borate family and the particulate additive is preferably calcium fluoride.
摘要:
A corrosion-resistant pipe coupling made of carbon steel has on its inner surface an intermediate annular projection directed radially inward. At least an innermost part of the annular projection is formed of corrosion-resistant material such as stainless steel. The annular projection is covered by a corrosion-resistant annular member which is secured by friction welding, electron beam welding, an adhesive or mechanical engagement. The annular member prevents corrosion of the coupling by corrosive fluids flowing in pipes.
摘要:
In the method of producing a double-wall composite tube by the steps of 1) applying heat to an outer tube (2), and 2) applying expanding pressure to an inner tube (3) inserted into the outer tube (2) so that the inner tube (3) expands in diameter into tight contact with the outer tube, at least one of the steps 1) and 2) is carried out with respect to a local zone of the tubes 2) and 3) which travels progressively from one end to the other of the tubes thereby to cause the outer tube (3) to sucessively expand locally in the travelling local zone and the inner tube (2) to undergo deformation in expansion to fit tightly against the outer tube (2), and the expanding pressure acting on the inner tube (3) is thereafter removed, the two tubes being left to attain the ambient temperature, whereby a tight interference fit is obtained therebetween. Radially-inward constrictive pressure is applied to the outer surface of the outer tube (2) which has been heated in said travelling local zone a die (32) which encircles the outer tube (2) and travels progressively from one end to the other end of the outer tube. Expansion pressure is applied to the inner tube (3) mechanically by mandrel (17a) which is drawn forcibly through the inner tube (3) from one end to the other end.