Indian Institute of Technology Hyderabad
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Characterization and Reactivity of TiO2/SiO2 Supported Vanadium Oxide Catalysts
No full textSeveral TiO2/SiO2 supports and supported vanadium oxide (vanadia) catalysts of varying titania and vanadia content are synthesized and characterized. Titania rutile phase is not detected for the TiO2/SiO2 supports even up to a calcinations temperature of 1073 K. The supported vanadia catalysts were also studied for the ethane and propane ODH reaction and compared with TiO2 (Degussa P25) supported catalysts. Surface vanadia species are present on the titania or silica part of the TiO2/SiO2 support depending on the titania and vanadia loading of the catalyst. Depending on the vanadia loading in the V2O5/TiO2/SiO2 catalyst the anatase to rutile phase transformation may occur below 1073 K. Furthermore, the ODH activity is retained or decreases less rapidly compared to the TiO2 supported catalyst as the calcination temperature is increased. Consequently, the TiO2/SiO2 supported vanadia catalysts do provide certain advantages compared to the TiO2 (Degussa P25) supported system
Characterization and Reactivity of TiO2/SiO2 Supported Vanadium Oxide Catalysts
No full texteveral TiO2/SiO2 supports and supported vanadium oxide (vanadia) catalysts of varying titania and vanadia content are synthesized and characterized. Titania rutile phase is not detected for the TiO2/SiO2 supports even up to a calcinations temperature of 1073 K. The supported vanadia catalysts were also studied for the ethane and propane ODH reaction and compared with TiO2 (Degussa P25) supported catalysts. Surface vanadia species are present on the titania or silica part of the TiO2/SiO2 support depending on the titania and vanadia loading of the catalyst. Depending on the vanadia loading in the V2O5/TiO2/SiO2 catalyst the anatase to rutile phase transformation may occur below 1073 K. Furthermore, the ODH activity is retained or decreases less rapidly compared to the TiO2 supported catalyst as the calcination temperature is increased. Consequently, the TiO2/SiO2 supported vanadia catalysts do provide certain advantages compared to the TiO2 (Degussa P25) supported system
Auditing Inference Based Disclosures in Dynamic Databases
No full textA privacy violation in an information system could take place either through explicit access or inference over already revealed facts using domain knowledge. In a post violation scenario, an auditing framework should consider both these aspects to determine exact set of minimal suspicious queries set. Update operations in database systems add more complexity in case of auditing, as inference rule applications on different data versions may generate erroneous information in addition to the valid information. In this paper, we formalize the problem of auditing inference based disclosures in dynamic databases, and present a sound and complete algorithm to determine a suspicious query set for a given domain knowledge, a database, an audit query, updates in the database. Each element of the output set is a minimal set of past user queries made to the database system such that data revealed to these queries combined with domain knowledge can infer the valid data specified by the audit query
d-Sequence edge binomials, and regularity of powers of binomial edge ideals of trees
Full text linkIn this paper, we provide the necessary and sufficient conditions for the edge binomials of the tree forming a d-sequence in terms of the degree sequence notion of a graph. We study the regularity of powers of the binomial edge ideals of trees generated by d-sequence edge binomials