A Chitosan/sucrose/polyurethane composite bio-membrane was prepared by the facile drop coating method. The composite bio-membrane had a porous spongy structure composed of a physical mixing of each component. The water absorbability of the composite bio-membrane increased with increasing chitosan and sucrose contents. Furthermore, the composite bio-membrane with immobilized Aspergillus sojae ex...

The review summarizes different bioinformatics tools used in studying the degradation of various xenobiotic compounds. Databases and Pathway Prediction Systems are key involved biodegradation. Several bio-degradative databases including EAWAG-BBD (Biocatalysis/Biodegradation Database), Plastics Microbial Biodegradation Database, ONDB (Organonitrogen Degradation Food risk component database (Foo...

We propose a two-pha.se algorithm for physical database design. In phase one the algorithm, for each logical query, loses rules to determine characteristics of a physical design (such as indexes) that would be beneficial to the query, and selects a physical design that yields a low cost estimate for that query. In phase two we use a notion of compromase between physical database designs. St,art...

In a high-level query language such as SQL, queries yield the same result no matter how the logical schema is physically implemented. Nevertheless, a query's cost can vary by orders of magnitude among di erent physical implementations of the same logical schema, even with the most modern query optimizers. Therefore, designing a low-cost physical implementation is an important pragmatic problem|...

Physical database design can be marked as a crucial step in the overall design process of databases. The outcome of physical database design is a physical schema which describes the storage and access structures of the stored database. The selection of an eecient physical schema is an NP-complete problem. A signiicant number of eeorts has been reported to develop tools that assist in the select...

Data warehousing has quickly evolved into a unique and popular business application class. A data warehouse stores materialized views of data from one or more remote sources, with the purpose of efficiently implementing decision support or OLAP (On-Line Analytical Processing) queries. One of more important decisions in designing data warehouse is the selection of materialized views to be mainta...

Data warehouses collect copies of information from remote sources into a single database. Since the remote data is cached at the warehouse, it appears as local relations to the users of the warehouse. To improve query response time, the warehouse administrator will often materialize views defined on the local relations to support common or complicated queries. Unfortunately, the requirement to ...

In order to extend database technology beyond traditional applications a new paradigm called \externalization of database functionality" has been proposed in research and development. Externalization of database functionality is a radical departure from traditional thinking. Traditionally, all data is loaded into and owned by the database, whereas in the new paradigm data may reside outside the...

The design of efficient physical databases is a complex activity involving the consideration of a large number of factors. Because of the complexity, mathematical programming approaches seeking to optimize the physical database have to make many simplifying assumptions; therefore, their applicability is limited. Further, the database designer may want to experiment with design preferences and f...