Abstract:
The invention relates to a process for preparation, under reducing conditions, of cooking liquors having high sulphidity for sulphate pulp cooking, wherein the black liquor obtained in the cooking process is fed, after evaporation, completely or partly to a reactor operating at increased temperature which is obtained by energy supply from an external heat source and/or release of energy from the black liquor, a melt essentially consisting of sodium sulphide being formed and withdrawn to be further processed to cooking liquor. The process of the invention is characterized in that in addition there are fed to the reactor the whole or part of sulphur-containing and/or sulphur- and sodium-containing materials present in the pulp mill, including sulphur-containing and/or sodium- and sulphur-containing make-up chemicals used for the total chemicals balance of the pulp mill, in such a way that the mole ratio of sodium to sulphur in the total mixture fed to the reactor is within the range of 1.5 to 4. According to a preferred embodiment of the invention there is used an aqueous solution of the sodium sulphide melt obtained in so-called modified sulphate cooking.
Abstract:
A semiconductor chip that emits radiation includes a semiconductor body having an active zone, which emits unpolarized radiation having a first radiation component of a first polarization and having a second radiation component of a second polarization. A lattice structure acts as a waveplate or polarization filter and causes an increase in one radiation component relative to the other radiation component in the radiation emitted by the semiconductor chip through an output side. Therefore, the semiconductor chip emits polarized radiation, which has the polarization of the amplified radiation component. The attenuated radiation component remains in the semiconductor chip an optical structure, which converts the polarization of at least part of the attenuated radiation component remaining in the semiconductor chip to the polarization of the amplified radiation component, and a reflective rear side opposite the output side.
Abstract:
The present invention relates to an environmental-friendly process for reducing the content of chloride in a liquor inventory of a chemical pulp mill. According to the invention, in a recovery system for pulping chemicals containing sulphur and an alkali metal, precipitator dust formed in a recovery boiler is collected and withdrawn, dissolved in water and electrolyzed for production of chlorine or hydrochloric acid in the anolyte. Since the dust normally contains a large amount of sodium sulphate, sulphuric acid and sodium hydroxide can also be produced in the electrolysis. To reduce the content of impurities, before the electrolysis, the pH of the aqueous solution is adjusted to above about 10 to precipitate inorganic substances which are separated-off together with flocculated or undissolved substances.
Abstract:
An edge-emitting semiconductor laser includes a first waveguide layer, into which an active layer that generates laser radiation is embedded. The laser also includes a second waveguide layer, into which no active layer is embedded. The laser radiation generated in the active layer forms a standing wave, which has respective intensity maxima in the first waveguide layer and corresponding intensity minima in the second waveguide layer and respective intensity minima in the first waveguide layer and corresponding intensity maxima in the second waveguide layer at periodic intervals in a beam direction of the semiconductor laser. An at least regionally periodic contact structure is arranged at a surface of the edge-emitting semiconductor laser. A period length of the contact structure is equal to a period length of the standing wave, such that the semiconductor laser has an emission wavelength that is set by the period length of the contact structure.
Abstract:
A ball nose end mill comprises a body having a semi-spherical front surface and a plurality of indexable cutting inserts. A central one of the inserts is of generally triangular shape, and the additional inserts are of generally rectangular shape. The central insert has a generally convexly curved top surface, and the cutting edges thereof include main cutting edges which are convexly curved when the central insert is viewed from the side.
Abstract:
An edge-emitting semiconductor laser includes a first waveguide layer, into which an active layer that generates laser radiation is embedded. The laser also includes a second waveguide layer, into which no active layer is embedded. The laser radiation generated in the active layer forms a standing wave, which has respective intensity maxima in the first waveguide layer and corresponding intensity minima in the second waveguide layer and respective intensity minima in the first waveguide layer and corresponding intensity maxima in the second waveguide layer at periodic intervals in a beam direction of the semiconductor laser. An at least regionally periodic contact structure is arranged at a surface of the edge-emitting semiconductor laser. A period length of the contact structure is equal to a period length of the standing wave, such that the semiconductor laser has an emission wavelength that is set by the period length of the contact structure.
Abstract:
A semiconductor chip that emits radiation includes a semiconductor body having an active zone, which emits unpolarized radiation having a first radiation component of a first polarization and having a second radiation component of a second polarization. A lattice structure acts as a waveplate or polarization filter and causes an increase in one radiation component relative to the other radiation component in the radiation emitted by the semiconductor chip through an output side. Therefore, the semiconductor chip emits polarized radiation, which has the polarization of the amplified radiation component. The attenuated radiation component remains in the semiconductor chip an optical structure, which converts the polarization of at least part of the attenuated radiation component remaining in the semiconductor chip to the polarization of the amplified radiation component, and a reflective rear side opposite the output side.