Data storage systems

In general, the commercially used optical data storage media deposit the information on disks or cards (two-dimensional data deposition. Table 1). Data storage systems, which store data in three and more dimensions are being developed. 

Fig. 16. Maximum achievable signal-to-noise ratio (SNR) on read-out of different writable optical data storage systems as a function of the writing energy (laser power) (121). SQS = Organic dye system (WORM) PC = phase change system (TeSeSb) MO = magnetooptical system (GbTbFe). See text.

The rapid development of microelectronics has enabled many similar measurements to be made with data collecting systems and then stored electronically. The raw data can then be downloaded to the data processing installation, where they can be plotted and evaluated at any time [1]. This applies particularly to monitoring measurements on pipelines for intensive measurements, see Section 3.7. Figure 3-1 shows an example of a computer-aided data storage system. 

Fig. 3-1 Computer-aided data storage system for monitoring the cathodic protection of a long-distance pipeline.

Provide data storage systems which enable rapid retrieval of records by product identification. 

Hunt, P. A. Optical Data-Storage Systems. In Chemistry and Technology of Printing and Imaging Systems Gregory, P., Ed. Blackie London, 1996. 

The purple membrane is harvested semiindustrially from halobacteria mutants which are bred in fermenters. The BR is then embedded into a polymeric matrix of poly(vinyl alcohol) or polyacrylamide. The BR films manufactured in this way are used for different applications, preferably in holography, for example, as a reversible transient data storage system for optical information processing (159). Another example is real-time interferometry by using the property of BR films to integrate over time (160). BR has been proposed also as a two-photon memory material because of its unusually large two-photon cross section. 

P. Hunt, Optical Data Storage Systems in Chemistry and Technologyof Printing and Imaging Systems, P. Gregory (ed.), Blackie, London, 1996. 

Scheme 4 Proposed optical data storage system based on optical switching of enantiomers, a) Writing with circularly polarized light (CPL), b) reading with linear polarized light (LPL) and erasing with unpolarized light (UPL).

Another interesting possible application of photochromic materials is in the construction of new data storage systems for computers. For some time, researchers have been considering the possibility of... 

Myung S. Jhon, Department of Chemical Engineering and Data Storage Systems Center, Carnegie Mellon University, Pittsburgh, PA 15213-3890, U.S.A. 

Iron-platinum alloy nanoparticles are very promising candidates for future data storage systems. They become available by simultaneous reduction of platinum acetylacetonate and the decomposition of Fe(CO)5 in oleic acid and oleyl amine.The composition of FexPti x can be varied between X = 0.48 and x = 0.7. The particles exhibit disordered fee structure. They are superparamagnetic at room temperature. Aimealing at 550-600 °C transforms the fee structure into a face-centered tetragonal (fet) one. These have been shown to be suited for storage devices owing to their room temperature coercivity. The exact transition temperature depends on the stoichiometry. 

Failure to establish appropriate procedures to assure that computerized processing control systems and data storage systems are secure and managed to assure integrity of processes and data that could affect conformance to specifications. [FDA, 2001]... 

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