摘要:
Provided is a method for the synthesis of N-protected bis-3,6-[4-aminobutyl]-2,5-diketopiperazine including the step of heating a solution of c-amino protected lysine in the presence of a catalyst selected from the group consisting of sulfuric acid, phosphoric acid, and phosphorus pentoxide.
摘要:
A binder composition for producing articles of bonded particulate material such as foundry moulds or cores comprises an alkaline aqueous solution of a resol phenol-aldehyde resin and an oxyanion capable of forming a stable complex with the resin the amount of alkali present in the solution being sufficient to substantially prevent stable complex formation. Bonded articles are produced from mixtures of particulate material and the binder composition by passing carbon dioxide gas through the formed articles whereby the oxyanion forms a stable complex with the resin and the resin is cured. The oxyanion may be for example borate, stannate or aluminate.
摘要:
A binder composition for producing articles of bonded particulate material such as foundry moulds or cones comprises an alkaline aqueous solution of a resol phenol-aldehyde resin and an oxyanion capable of forming a stable complex with the resin the amount of alkali present in the solution being sufficient to substantially prevent stable complex formation. Bonded articles are produced from mixtures of particulate material and the binder composition by passing carbon dioxide gas through the formed articles whereby the oxyanion forms a stable complex with the resin and the resin is cured. The oxyanion may be for example borate, stannate or aluminate.
摘要:
A binder composition in aqueous solution, suitable for use in the production of foundry sand moulds and cores is obtained by mixing(i) an alkali silicate(ii) a substantially water soluble carbohydrate selected from monosaccharides, disaccharides, polysaccharides and derivatives thereof and(iii) a phenolic compound selected from monohydric phenols, dihydric phenols, trihydric phenols, phenols of polynuclear hydrocarbons and phenolic acids, which is miscible with or soluble in an aqueous solution of an alkali metal silicate.The composition may also contain an oxyanion such as a borate which is capable of forming a water soluble complex with the carbohydrate.A mixture of phenolic compounds, such as a mixture consisting predominantly of isomers of di- and trihydroxy diphenyl obtained in the distillation of crude resorcinol, may be used.The preferred carbohydrate is a stabilized starch hydrolysate whose reducing power has been removed by a process such as hydrogenation.
摘要:
A heater comprises a combustion tube connected to receive gaseous fuel or liquid fuel dispersed within a gaseous carrier gas from a source. The combustion tube communicates with an expansion chamber whose surface is provided with a plurality of openings. The expansion chamber is housed within a perforated container, the internal surface of which is spaced from the external surface of the expansion chamber to receive heating blocks.
摘要:
A binder composition in aqueous solution, suitable for use in the production of foundry sand moulds and cores is obtained by mixing an alkali metal silicate, glycosylated polyhydric alcohols produced by acid catalyzed condensation of a carbohydrate having a reducing group and an alcohol having two or more hydroxyl groups, and optionally an oxyanion salt such as a borate.
摘要:
Various systems and methods for computer memory management are described herein. A system for computer memory management includes a first memory device including a mapping table; a second memory device including a staging area; a third memory device including a dedup data region; and a controller operable to: receive a memory access request, the memory access request including an address and data; write the data to the staging area; and update the mapping table with the address.
摘要:
Disclosed is a method to safely terminate a runaway reaction within a reaction vessel, comprising: sensing an increase in pressure in the reaction vessel, opening a barrier blocking a flow path into the reactor, wherein the barrier opening is achieved via a mechanical response to the sensed increase in pressure, and injecting a kill agent into the reaction vessel via the opened flow path, thereby terminating the reaction. Also disclosed is a system for performing the method. The system functions without an external electrical source and is therefore compliant with ASME standards.
摘要:
A new cultivar of Corokia plant named ‘Phantom’ that is characterized by narrow leaves that are colored dark brown on the upper surface and vigorous growth.
摘要:
A new cultivar of Corokia plant named ‘Phantom’ that is characterized by narrow leaves that are colored dark brown on the upper surface and vigorous growth.