Abstract: Method for manufacturing a series-connected thin-film solar module of crystalline silicon upon which is formed an electrically conductive layer upon which is formed a p-doped polycrystalline silicon layer which is about 50 microns thick both being deposited on a large area of glass or ceramic substrate and a pn junction is formed in the p-doped polycrystalline silicon layer. Individual cells that have a width between one to two centimeters are formed by forming trenches so as to electrically insulate them from each other in the silicon layer and the trenches are filled with an insulator material. Front electrodes and electrodes for series interconnecting the individual cells are formed over the cells and into holes formed for that purpose and the method saves up to 80% of silicon material as compared to prior art methods.

Abstract: A centrifugal pump comprises a casing which has two volutes disposed substantially diametrically opposite each other in such a way that the end of the first volute is adjacent to the start of the second volute. The outer diameter of the casing approximates or equals the diameter of the first volute in the region of the end of the first volute. This contributes to compactness of the casing. The volutes surround a rotary impeller or a guide wheel which is installed in the casing downstream of the impeller. Each volute extends along an arc of at most 180 degrees. The casing can have one or more elongated channels extending from the end of the first volute, along the second volute, and to a common outlet nozzle for both volutes.

Abstract: The double volute casing of a centrifugal pump has a main portion which has first and second volutes extending along arcs of not more than 180 degrees. The outer diameter of the main portion equals or approximates the outer diameter of the end of the first volute, and such end is adjacent to the start of the second volute whose end communicates with an outlet nozzle of the main portion. The latter has two channels which flank the second volute and extend between the end of the first volute and the outlet nozzle. The inner sides of the channels are open and face the axial passage of the main portion. Such inner sides are sealed from the axial passage by tubular inserts which are installed in and are separably fastened to the main portion of the casing. The passage receives a single-suction or a double-suction impeller or a stationary guide wheel which is located downstream of the impeller. The main portion of the casing is a one-piece casting.