Abstract: Non-linear resistors especially suitable for assembling into a stack are disclosed herein along with the stack and its method of assembly. Each resistor has opposite end surfaces to which a certain electrically conductive bonding substance, specifically solder, will adhere and an outer circumferential side surface extending between the end surfaces. The entire side surface of each wafer is covered with a coating layer formed from a dielectric composition to which the specific bonding substance will not adhere. This composition is also one which is able to withstand coming into contact with the bonding substance when the latter is in a liquid state, that is, it is able to withstand the temperature of molten solder when solder is used as the bonding substance and it must also be able to withstand the expected voltage and current levels across the wafer without any adverse effects.

Abstract: Low-sulfur and low-ash gaseous, liquid and solid fuels are made from coal by a process which first subjects the coal to solvent extraction and hydrotreatment under hydrodesulfurizing conditions in a coal liquefaction zone to reduce the organic sulfur content of the coal. The effluent is divided into a low-solids product which contains most of the extract and a high-solids product which contains most of the remaining inorganic sulfur and other mineral matter. The low-solids product stream which contains extract and solvent is subjected to a forming step to yield low-ash and low-sulfur pellets. The high-solids product stream is subjected to gasification to yield hydrogen for use in the liquefaction step. The process is particularly adapted to supply the energy needs of a steel plant, including the required coke.