MIDAS database

Dr. Schondelmeyers report to OTA is based on data from the IMS America, Inc. MIDAS system using the United States Drugstore and United States Hospital database. That database does not include sales made directly to mail-order distributors, health maintenance organizations, or Federal Government health purchasers (such as the U.S. Department of Veterans Affairs and the military.) In 1986, IMS America claimed the database reflected 98 percent of ethical pharmaceutical sales in the United States (368), but this share may be declining as mail-order pharmacies become more important. 

Based on a comprehensive evaluation of the viscosity of 50 fluids (Stephan Lucas 1979) the MIDAS database for transport properties was founded at the institute of the authors in 1979 in order to overcome the above mentioned problems by providing users from industry, universities and other institutions with reliable, thermodynamically consistent data covering a wide range of fluid state (Laesecke et al. 1986). 

The structure of the MIDAS database system is outlined in Fig ure 17.1. The kernel of the system is built by the database blocks REFERENCES and DATASETS, each consisting of two main tables and representing the bibliographic and numerical part of the database, respectively. Both database blocks are connected by the key column RENO that represents a serial, unique reference number. The auxiliary database tables TABJOU, TABMET, TABSUB complete the MIDAS database system. 

Statistical information about the MIDAS database is given in Table 17.1, split up into information on pure fluids, binary, ternary and quaternary mixtures. The database table TABREF contains 5100 publications. More than 16,500 data sets published in them are registered in TABCON. They all have to be entered in TABSET where up to now nearly 3900 data sets are already registered. These data sets consist of more than 280,000 points. 

Table 17.2. Publications on substance properties resulting from the MIDAS database...

In view of these environmental problems the MIDAS database system was extended to thermophysical properties of environmentally acceptable refrigerants and their mixtures. 

The MIDAS database system is installed on a DEC VAX Workstation 3200. On-line access is not feasible at present, but the data may be mailed by listing, 3.5- or 5.25-inch diskettes or electronic mail. Requests should be addressed to ... 

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