Abstract: A pneumatic dredger bulk conveyor of the type wherein a conveyor line is formed by a first circular outer tube and a first inner tube telescopically slidable therein and a pressure line is formed by a second outer tube fixed to the first outer tube and a second inner tube telescopically slidable in the second outer tube in coordinated movement with the first inner tube, the improvement which comprises an upper circular guide member formed at the upper end of the first inner tube and closely spaced from the first outer tube defining a first circular interspace therewith, the first inner tube having below the upper guide member a polygonal profile forming a second interspace with the first outer tube having a greater cross sectional area than the first interspace and constituted by a plurality of first segmented passages of greater width than the first interspace and each of which is bounded by an arc of the first outer tube and a plane of the polygonal profile.

Abstract: A compressed air dredge for removing gravel, sand, mud or the like from the sea floor is provided of the type including a compressor which is installed on a dredging ship having a vertically-disposed feed pipe and which, via a compressed air line, blows compressed air into the bottom end of the feed pipe so as to provide the required suction force. The dredge is characterized by the provision of at least two vertically disposed feed pipes, each of which is coupled to a separate compressor and each of which is provided with a separate compressed air line. The compressed air lines are coupled together via a coupling line having shut-off means for establishing and closing-off communication between the two compressed air lines.

Abstract: In a method and system for adjustment of a specimen supported by a specimen upport able to be changed over from one clutch state to another, the specimen is on a specimen table of an electronmicroscope or other corpuscular beam apparatus, and adjustment of the specimen table normal to a longitudinal axis of the apparatus is possible in two coordinate directions. The specimen support is first coupled to the specimen table which is then adjusted such that the specimen is put into a desired position in relation to the apparatus axis. The specimen support then is coupled up with a holding member, which, as long as the specimen support is joined to it, is generally fixed in position. The specimen table is then readjusted into a certain desired position and the specimen support is then again coupled with the specimen table.

Abstract: A corpuscular beam microscope for ring segment focusing is provided with a ondenser and an objective magnetic lens system which is disposed substantially axially symmetrically about the microscope axis for the purpose of generating two field maxima separated by a distance not exceeding five times the arithmetic means of half the half height widths of the component magnetic fields forming the maxima. The provision of such a magnetic lens system facilitates the elimination of aperture aberrations of the first and second order and the elimination of chromatic aberrations of zero order and partly of the first order as well as certain extra-axial defects.

Abstract: A transmission-type charged particle beam apparatus comprising a vacuum elope enclosing, first means, having at least ten individual charged particle sources to separately produce at least ten individual charged particle beams, second means to supporting a specimen to be investigated; third means to project each of the beams along a different beam path through a predetermined region of the specimen, the beam paths collectively converging about a rotational axis of symmetry at equal angles of at least 30.degree.

Abstract: A composition comprising a granular inorganic oxidic material other than glass powder and 1 to 30 weight percent, based on the weight of said material, of glass powder, especially a composition additionally containing a hardenable thermo- or cold-setting phenolic resin, which composition does not disintegrate at high temperatures and retains compressive strength.

Abstract: A metallurgical vessel having a tap hole containing a plug comprised of a hardened composition comprising a granular inorganic oxidic material other than glass powder and 1 to 30 weight percent, based on the weight of said material, of glass powder, especially a composition additionally containing a hardenable thermo- or cold-setting phenolic resin, which composition does not disintegrate at high temperatures and retains compressive strength.

Abstract: A composition comprising a granular inorganic oxidic material other than glass powder and 1 to 30 weight percent, based on the weight of said material, of glass powder, especially a composition additionally containing a hardenable thermo- or cold-setting phenolic resin, which composition does not disintegrate at high temperatures and retains compressive strength.

Abstract: A corpuscular beam microscope, specifically an electron microscope, inclug means for adjusting the position of the object image in the microscope, and means, coupled to said adjusting means, for determining and correcting drift of the object image by means of a control signal which controls the adjusting means and is derived from a convolution of an actual object image with a stored reference object image. The improvement of the invention comprises the provision of means for deriving the convolution by imaging the actual object image directly on the reference object image.A method for determining the convolution of the actual and reference object images in which the brightness values of the images are reduced to two values and the images are subsequently brought into coincidence is also disclosed.

Abstract: The determination and correction of the image drift in an electron microse is accomplished using a correction signal obtained by forming the convolution product of an actual object image (instantaneous microscope image) and a reference object image (microscope image at an earlier point in time) whose change in position is proportional to the image drift. The convolution product preferably is formed using an optical analog computer. To correct the image drift, the correlation signal is used as the controlled variable which acts on the image adjusting means.

Abstract: Object positioning apparatus for positioning the object to be observed in a orpuscular beam apparatus such as an electron microscope or the like having both lateral or rotational degrees of freedom in which means are provided to mechanically separate the lateral motion and rotational or tilting motion of the object whereby a point on the object can be laterally positioned on the rotational axis and after separation from the lateral moving means may then be rotated or tilted without wandering out of the field of view of the microscope.

Abstract: For dark-field imaging of the specimen, a scanning corpuscular-beam micrope is equipped with multiple annular apertures located between the beam source and the specimen on the one hand and between the specimen and the detector on the other hand. The areas of the multiple annular apertures conjointly i.e. complementarily cover the ray path. The aperture situated in front of the detector is surrounded by a wide, radiation-transmitting region. The invention affords utilizing for the generation of the image not only the rays scattered outside of the aperture cone but also a large part of the rays scattered within this cone.