Qualitative development requirements

Qualitative Development Requirements Information (QDRI). Information concerning items of Ordnance which will require future development. This information is furnished by class II Ordnance installations having a research and development mission to civilian organizations properly qualified by Ordnance Districts Qualitative Materiel Development Objective (QMDO). A Department of the Army approved statement of a military need for development of new materiel, the feasibility of which cannot be determined sufficiently to establish a qualitative materiel requirement... 

After solvent development, the detection procedures can be either qualitative or quantitative. Qualitative procedures require that a drug product be identified on the chromtographic plate as having the identical Rf and at about equal magnitude to a reference sample. Semiquantitative estimations can be a visual comparison of the size and intensity of the spots versus various standard concentrations. Quantitative procedures require either densitometry or the extraction of the components of interest from the sorbent followed by spectrophotometric measurement. 

Thus, the majority of messenger RNA molecules or their precursors seem to be transcribed from the single copy DNA base sequences. At the same time, it was shown above that large changes in RNA transcriptional products from the repeated DNA base sequences are also detectable in developing systems and, therefore, the total picture of qualitative and quantitative changes in transcription in development requires the analysis of both the repeated and nonrepeated portions of the genome. 

Attempts have been made to place the design of packed columns on a sound theoretical basis to avoid the large amount of empirical work with which it is frequently associated. The theory is often only approximate and cannot therefore be used as the sole guide for design purposes. It does however at least allow valuable qualitative or semi-quantitative predictions to be made, which reduces the development requirement. 

At present it is common that when placing an order for developing and designing complex technical systems, it is essential to include both quantitative and qualitative reliability requirements for a specific system (lEC 2007). 

In this section, the conceptual framework of molecular orbital theory is developed. Applications are presented and problems are given and solved within qualitative and semi-empirical models of electronic structure. Ab Initio approaches to these same matters, whose solutions require the use of digital computers, are treated later in Section 6. Semi-empirical methods, most of which also require access to a computer, are treated in this section and in Appendix F. 

Mechanistic Approaches. Adequate and appropriate river-quality assessment must provide predictive information on the possible consequences of water and land development. This requires an understanding of the relevant cause and effect relationships and suitable data to develop predictive models for basin management. This understanding may be achieved through qualitative, semi-quantitative or quantitative approaches. When quantitative or semi-quantitative methods are not available the qualitative approach must be applied. Qualitative assessments involve knowledge of how basin activities may affect river quality. This requires the use of various descriptive methods. An example of this kind of assessment is laboratory evaluation of the extent to which increases in plant nutrients, temperature or flow may lead to accelerated eutrophication with consequent reduction of water quality. 

Modelling can at least facilitate the determination of the most effective scale-up program. Information from three fields is needed for modelling (1) chemical kinetics, (2) mass transfer, and (3) heat transfer. The importance of information for different processes has been qualitatively evaluated (see Table 5.3-5). Obviously, sufficiently accurate information on heat transfer is needed for batch reactors, which are of great interest for fine chemicals manufacture. Kinetic studies and modelling requires much time and effort. Therefore, the kinetics often is not known. Presently, this approach is winning in the scale-up of processes for bulk chemicals. The tools developed for scale-up of processes for bulk chemicals have been proven to be very useful. Therefore, the basics of this approach will be discussed in more detail in subsequent sections. 

However, there is still a strong need to develop new methods that will be able to quantitatively or at least qualitatively estimate the prediction accuracy of log D models. Such models will allow the computational chemist to distinguish reliable versus nonreliable predictions and to decide whether the available model is sufficiently accurate or whether experimental measurements should be provided. For example, when applying ALOGPS in the LIB RARY model it was possible to predict more than 50% and 30% compounds with an accuracy of MAE <0.35 for Pfizer and AstraZeneca collections, respectively [117]. This precision approximately corresponds to the experimental accuracy, s=0.4, of potentiometric lipophilicity determinations [15], Thus, depending on the required precision, one could skip experimental measurements for some of the accurately predicted compounds. 

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