摘要:
The rate of formation of carbon on the surfaces of thermal cracking tubes and the production of carbon monoxide during thermal cracking of hydrocarbons are inhibited by the use of cracking tubes treated with an antifoulant, including tin compound, silicon compound and sulfur compounds in the presence of a reducing gas such as hydrogen. Additionally, the concentration of carbon monoxide in a pyrolytic cracking process product stream is reduced by the treatment of the thermal cracking tubes of such process with a reducing gas having a concentration of a sulfur compound.
摘要:
A method is disclosed for micromachining the surface of a silicon substrate which encompasses a minimal number of processing steps. The method involves a preferential etching process in which a chlorine plasma etch is capable of laterally etching an N+ buried layer beneath the surface of the bulk substrate. Such a method is particularly suitable for forming sensing devices which include a small micromachined element, such as a bridge, cantilevered beam, membrane, suspended mass or capacitive element, which is supported over a cavity formed in a bulk silicon substrate. The method also permits the formation of such sensing devices on the same substrate as their controlling integrated circuits. This invention also provides novel methods by which such structures can be improved, such as through optimizing the dimensional characteristics of the micromachined element or by encapsulating the micromachined element.
摘要:
An extractive distillation process for separation ethers (in particular methyl t-butyl ether or ethyl t-butyl ether), aliphatic hydrocarbons (in particular isobutane and/or isobutene) and alcohols (in particular methanol or ethanol) employs as solvent sulfolane(s) and/or dialkyl sulfone(s), or N-(.beta.-mercaptoalkyl)-2-pyrrolidone(s), or a mixture of N-alkyl-2-pyrrolidone(s) and either sulfolane(s) or glycol compound(s).
摘要:
The separation of alkadienes from close-boiling alkenes by extractive distillation employes as solvent N-methyl-2-thiopyrrolidone, alone or in admixture with unsubstituted sulfolane (cyclotetramethylene sulfone), or a mixture of unsubstituted sulfone and N-methyl-2-pyrrolidone. The separation of cycloalkadienes from close-boiling alkadienes by extractive distillation employs N-methyl-2-thiopyrrolidone as solvent.
摘要:
A mixture of (a) at least one N-alkyl-2-pyrrolidone (preferably N-methyl-2-pyrrolidone) and (b) at least one glycol compound (preferably ethylene glycol or tetraethylene glycol) is used as solvent in the extractive distillation of a feed mixture of cycloalkane(s) (in particular cyclohexane) and close-boiling alkane(s).
摘要:
An extractive distillation process for separating at least one cycloalkane from at least one close-boiling alkane employs as solvent a mixture of (a) at least one saturated C5-C9 alcohol (preferably cyclohexanol) and (b) at least one glycol compound (preferably tetraethylene glycol).
摘要:
A limb protective covering is provided having a tubular sleeve of plastic and an integral hand or foot receiving member and an elongate closure strap heat sealed along a transverse line intermediate its ends to the sleeve, and having an overlying stabilizing loop over the closure strap at the heat sealed line.
摘要:
A limb protective covering is provided having a tubular sleeve of plastic and an integral hand or foot receiving member and an elongate closure strap having a panel intermediate its ends fastened to the sleeve by fastening to an inner rigidifying panel with the sleeve sandwiched between.