779results about How to "Reduce the presence of impurities" patented technology

The invention is directed to polyester processes that utilizes a pipe reactor in the esterification, polycondensation, or both esterification and polycondensation processes. Pipe reactor processes of the present invention have a multitude of advantages over prior art processes including improved heat transfer, volume control, agitation and disengagement functions. The pipe reactor processes and apparatus of the present invention are built and operated at a much lower cost than conventional polyester processes.

An SOI substrate having on the surface thereof a single crystal silicon film formed on an insulator is heat-treated in a hydrogen-containing reducing atmosphere in order to smooth the surface and reduce the boron concentration without damaging the film thickness uniformity in a single wafer and among different wafers. The method is characterized in that the single crystal silicon film is arranged opposite to a member of non-oxidized silicon for heat treatment.

A method for fabricating MOS-FET using a SOI substrate includes a process of ion implantation of an impurity into a channel region in a SOI layer; and a process of channel-annealing in a non-oxidized atmosphere. In the ion implantation process, a concentration peak of the impurity is made to exist in the SOI layer. Moreover in the channel-annealing process, the impurity is distributed with a high concentration in the vicinity of the surface of the SOI layer under the following condition with the anneal temperature as T (K) and annealing time as t (minutes):506×1000 / T−490<t<400×1000 / T−386.

The invention is directed to polyester processes that utilizes a pipe reactor in the esterification, polycondensation, or both esterification and polycondensation processes. Pipe reactor processes of the present invention have a multitude of advantages over prior art processes including improved heat transfer, volume control, agitation and disengagement functions.

Embodiments include methods for recovering petroleum products from a formation containing heavy crude oil. In one embodiment, a method includes flowing a catalytic material containing the nanocatalyst into the formation containing the heavy crude oil and exposing the heavy crude oil and the catalytic material to a reducing agent (e.g., H2). The method further includes positioning a steam generator within the formation, generating and releasing steam from the steam generator to heat the heavy crude oil containing the catalytic material, forming lighter oil products within the formation, and extracting the lighter oil products from the formation. In another embodiment, a method includes exposing the heavy crude oil and the catalytic material to an oxidizing agent (e.g., O2). The nanocatalyst may contain cobalt, iron, nickel, molybdenum, chromium, tungsten, titanium, oxides thereof, alloys thereof, or combinations thereof.

A process for producing a purified carboxylic acid having “n+1” carbon atoms comprises feeding a carboxylic acid stream containing a carboxylic acid having “n+1” carbon atoms, a hydrogen halide, a lower boiling point (bp) component, a higher bp component, and others to a first distillation column; separating a lower bp fraction containing part of the lower bp component and a higher bp fraction containing part of the higher bp component in the first column; withdrawing a side stream containing at least the carboxylic acid by side cut from the first column; feeding the side stream to a second distillation column; separating a lower bp fraction containing part of the lower bp component and a higher bp fraction containing part of the higher bp component in the second column; and withdrawing a side stream containing the carboxylic acid by side cut from the second column to recover a purified carboxylic acid; and the process further comprises feeding at least one first component (A) selected from the group consisting of an alcohol, corresponding to the carboxylic acid, having “n” carbon atom(s), and an ester of the alcohol with the carboxylic acid to the first column, and if necessary water. Such a process ensures reduction of the concentration of the hydrogen halide in the purified carboxylic acid.

A pair of undoped spacer layers are provided adjacent to, or near to, a single quantum well aluminum gallium nitride active region. In various exemplary embodiments, the undoped spacer layers are provided between the single quantum well aluminum gallium nitride active region and carrier confinement layers. The undoped spacer layers reduce the threshold current for the laser device and improve the output characteristics.

An object is to provide a semiconductor device having stable electric characteristics in which an oxide semiconductor is used. An oxide semiconductor layer is subjected to heat treatment for dehydration or dehydrogenation treatment in a nitrogen gas or an inert gas atmosphere such as a rare gas (e.g., argon or helium) or under reduced pressure and to a cooling step for treatment for supplying oxygen in an atmosphere of oxygen, an atmosphere of oxygen and nitrogen, or the air (having a dew point of preferably lower than or equal to −40° C., still preferably lower than or equal to −50° C.) atmosphere. The oxide semiconductor layer is thus highly purified, whereby an i-type oxide semiconductor layer is formed. A semiconductor device including a thin film transistor having the oxide semiconductor layer is manufactured.

A pair of undoped spacer layers are provided adjacent to, or near to, a single quantum well aluminum gallium nitride active region. In various exemplary embodiments, the undoped spacer layers are provided between the single quantum well aluminum gallium nitride active region and carrier confinement layers. The undoped spacer layers reduce the threshold current for the laser device and improve the output characteristics.

This invention discloses a soft joint of a cross-linked polythene cable including an inner semiconductive layer and metal jacket sleeves, in which, two core leads between two cables are welded to form a core connection part, the inner semiconductive layer is combined with a preserved section of the inner screen layer of the cable characterizing in setting a polythene filled vulcanized insulation layer out of the inner semiconductive layer to be fused with the polythene insulation layer of the cable, and wrapping the polythene insulation of the cable with a transition connection section and an outer semiconductive layer combining with the preserved section of the outer screen of the cable is set out of the polythene filled vulcanized insulation layer, two ends of the metal jacket sleeve are welded with the out surfaces of lead protection pipe of the cable and set with slope connection sections.

The present invention relates to the use of isomerization inhibitors in olefin metathesis reactions. The inhibitors are low molecular weight organic acids such as formic acid, acetic acid, benzoic acid, and the like.