Reference files

Drawing and Print Fiie. A good print file is a vital tool for any maintenance organization. Reference files in a large or multi-plant company can be particularly burdensome for several reasons ... 

If reviewers of completed forms are not the preparer, they need to be trained in procedures to audit the quality of the collected information and documentation files. This training may include means to check the completeness and credibility of the collected data by cross checking the data against other reference files, such as maintenance files or operating logs. 

Fair if unknown has limited fragmentation and is in the reference file. 

Excellent if unknown is in reference file. Compounds of closest match may have similar structure to un3cnown. 

Excellent if unJutown is in reference file. Poor if unknown spectrum contains contaminant peaks. Better than whole spectrum search for Impure spectra. 

Slow, efficient progreuaing required and large data storage for reference files. Identification of multiple components of mixtures can lie achieved by using residual spectrum. 

The SAS IMPORT procedure (PROC IMPORT) provides a quick way to read an ASCII text file into SAS. You can call PROC IMPORT by typing in the SAS code, or you can use the convenient SAS Import Wizard to build the PROC IMPORT code for you. Let s start by looking at using the SAS Import Wizard to import the following pipe-delimited (using the character ) laboratory normal range reference file ... 

Because of the number of standards in the PDF, it is not possible, in general, to search each entry individually. However, in many situations the analyst either knows or can make an educated guess as to the probable identity of the unknown. In this intuitive case, the PDF can be consulted directly and the cards for the suspected compounds can be consulted quickly. In fact, when a specific phase diagram is being investigated it is common practice to obtain powder diffraction patterns of all known phases in the system. If the 20 axis of these "reference" patterns is the same as that for unknown patterns, an unknown pattern can be compared directly to these relatively few standards on an illuminated viewing table and the diffraction lines from the known phases can be identified on the unknown pattern. As new phases are discovered and identified, their patterns may then be added to this reference file. 

A mass spectrum of a calibration solution is acquired (calibration file) and matched against a table of the expected masses of the peaks in the calibration solution that are stored in a reference file. 

Each peak in the reference file is matched to a corresponding peak in the calibration file. 

Peak maximum standard deviation or maximum difference between the predicted and actual mass. During calibration the difference between the measured mass in the acquired calibration file and the true mass in the reference file is taken for each pair of matched peaks. If this value exceeds the set value, the calibration will fail. Reducing the value of the standard deviation gives a more stringent limit, while increasing the standard deviation means that the requirement is easier to meet, but this may allow incorrect peak matching. 

Failed calibration. There are number of reasons for a calibration to fail. If an automated calibration method is used, it is possible that the reference peaks are not recognized when the reference file and calibration file are compared. This can be due to the following reasons ... 

Now load the expanded H spectrum of glucose D NMRDATA GLUCOSE 1D H GH 002999.1R and calibrate this spectrum with respect to the spectrum stored above. Use the Select Compare File button in the Calibration dialog box and use the calibrated spectrum D NMRDATA GLUCOSE 1D H GH 001999.1R as the reference file. Activate the File Compare Mode for x box. Check the shift value of the anomeric proton before and after the calibration process initialized by clicking the OK button. Store the calibrated spectrum under its original name. 

Nuclear Science Reference File — a bibliographic computer file of nuclear science references continually updated and maintained by the National Nuclear Data Center, Brookhaven National Laboratory, Recent literature is scanned by D. Winchefl. 

Standard reference collections. The Law Enforcement Standards Laboratory of NBS has been investigating the needs and uses of standard reference files or collections of select groups of forensic materials. 

In the substructure search the query (input) is small compared to the reference structures. The goal is to find all structures from the reference file that contain the query as a substructure. In the superstructure search the investigated (input) structure is large compared to structures in the reference file which is usually much shorter than in the case of substructure search. The purpose of the superstructure search is to identify all structures (skeletons, substituents, parts) from the reference file that fit into the query structure (Fig. 4.4). 

Superstructure search consists of a number of substructure searches in each of which the reference file contains only one structure, namely, the query. The number of substructure searches is equal to the number of structures in the reference file of the superstructure search. 

As already mentioned, the comparison of structures is a tedious and time consuming procedure. Therefore, the part where atom-by-atom and bond-by-bod comparisons are made should be executed on a file containing only a number of structures as small as possible. To achieve this, a fast scan of a long reference file should be made to select only the structures that possibly contain the query. 

Fig. 4.4 A substructure (left) and superstructure (right) search. In the substructure search the query is usually smaller compared with the structures in the reference file, while in the case of superstructure search the reference file is much shorter and containes only small fragments and/or skeletons.

There are no comprehensive data files for CD spectra for SRM s that compare with the many exhaustive files for absorbance data, either electronic or vibrational. Nor is there a plan in place to compile such a compendium. Analysts are required therefore to prepare their own reference files using whatever SRM s might be available from the usual manufacturers of fine chemicals. An obvious difficulty associated with this endeavor is the fact that although these materials are certified to be chemically pure few are ever certified to be 100% enantiomerically pure. More likely than not, these few materials have natural, rather than synthetic, origins. In actuality such materials probably do not exist. If they do, proof of their absolute enantiomeric purity is beyond the capabilities of currently available analytical methods [31]. Tn addition enantiomeric purity can be a time dependent transient state for materials that are prone to racemization, a process that is most likely for chiral liquids and chiral solutes in solution. It is not possible therefore to speak with conviction about exact molar ellipticity values. 

However, almost any unknown will contain some substructures which are well-represented in the reference file. Because of this, useful substructural information can be obtained from retrieval program results, as the best-matching compounds often show structural features similar to those of the unknown. For example, SISCOM (which recognizes structural Similarity COding Multiple matching factors) provides such substructural information as well as a matching capability (4). "Pattern recognition" (19J is a... 

When complex software is installed on a computer, the correctness and completeness of the installed program and data files should be verified. Vendors can assist this process by supplying installation reference files and automated validated verification procedures. 

Abstract [typescript] of Jack Dayton Key, An Analysis of the U.S. Army Supply Tables Used During the Civil War Period, master s thesis, 1960, Kremers Reference Files, C46 (B)I, Madison, WI American Institute of the History of Pharmacy. 

Complete list of volunteers (anticholinesterase chemicals) with volunteer numbers (not names), agents, doses, and dates-of exposure Identified contains master file and reference file of Edgewood reports... 

---