Abstract: Water heater relief valves intended to safeguard against overpressure and overtemperature emergencies are frequently rendered inoperative by corrosion or calcification. These problems are ameliorated by enclosing all or part of the valve mechanism in a sealed chamber containing a corrosion inhibiting medium, which may be an oil.

Abstract: Water heater relief valves intended to safeguard against overpressure and overtemperature emergencies are frequently rendered inoperative by corrosion or calcification. These problems are ameliorated by enclosing all or part of the valve mechanism in a sealed chamber containing a corrosion inhibiting medium, which may be an oil.

Abstract: The present invention is a writing apparatus that is capable of producing a calligraphic line of varying thickness but at a low cost and without requiring the user to have specialized training. The core components of the invention are a hollow tube, a stopper means, a hollow nib, and a roller.

Abstract: A bicycle has both manual drive and pedal drive assemblies which may be operated simultaneously or independently. The manual drive assembly is connected to the front wheel and the pedal drive assembly is connected to the rear wheel. Both the manual and pedal drive assemblies incorporate chain drive mechanisms as well as crank assemblies. The manual crank assembly is mounted at the top of the front fork journal and also serves as a handlebar assembly for steering the bicycle. In order to provide sufficient clearance between the chain which extends alongside the front forks and the frame, the frame is bent laterally (just behind the steering sleeve) to accommodate the chain during steering movements. In a first embodiment, the frame member extends generally downwardly and rearwardly from the steering sleeve to a sufficient degree to provide sufficient clearance between the crank assembly to allow the bicycle to be steered while the front wheel is being manually driven.

Abstract: A process for treating heavy crude oil feedstocks to reduce the asphaltenes, metals and sulfur content thereof while maintaining a high conversion thereof comprising: subjecting the feedstock to an asphaltene separation stage and thereafter subjecting the deasphaltene crude to a first hydrotreatment stage employing a first macroporous catalyst so as to produce an intermediate partially demetallized and desulfurized product and thereafter treating said intermediate product in a second hydrotreatment stage using a microporous catalyst wherein the microporous catalyst exhibits extended life period.

Abstract: A natural active stable catalyst for use in the hydrodemetallization (HDM) and the hydroconversion (HC) of heavy crudes and residues and, in particular, a method for the preparation of the catalyst from natural clay and a process for the treatment of heavy crudes and residues with the catalyst. The catalyst is free of hydrogenating metals of Groups VIB and VIII of the Periodic Table and comprises primarily iron, silica and alumina derived from the composition of the natural clay. The catalyst possesses a surface area of between 20 to 100 m.sup.2 /g, a total pore volume of between 0.20 to 0.90 cc/g, where 50 to 100% of the total pore volume contains pores of diameter greater than 400 .ANG.. The catalyst has a ratio I(Fe)/I(Si+Al) of between 0.2 to 0.9 as determined by XPS.

Abstract: A natural active stable catalyst for use in the hydrodemetallization (HDM) and the hydroconversion (HC) of heavy crudes and residues and, in particular, a method for the preparation of the catalyst from natural clay and a process for the treatment of heavy crudes and residues with the catalyst. The catalyst is free of hydrogenating metals of Groups VIB and VIII of the Periodic Table and comprises primarily iron, silica and alumina derived from the composition of the natural clay. The catalyst possesses a surface area of between 20 to 100 m.sup.2 /g, a total pore volume of between 0.20 to 0.90 cc/g, where 50 to 100% of the total pore volume contains pores of diameter greater than 400 .ANG.. The catalyst has a ratio I(Fe)/I(Si+Al) of between 0.2 to 0.9 as determined by XPS.