Words definitions/terminology

In this equation i represents the first eluting peak of a peak pair and j the last eluting peak. Hence, by definition a is always larger than unity. Sometimes a is called the separation factor, which is somewhat unfortunate terminology because separation is influenced by other factors than just a (see section 1.3). a is the chromatographic parameter that is most directly related to the selectivity of the phase system. In this book, therefore, the word selectivity will often be associated with a. Using eqns.(1.7) and (1.10) we can write two other equations for a, . 

Some of the examples and discussion in this chapter draw on the two-class classification problem, which here is hit versus inactive . The word active refers to a validated hit, that is, a molecule that truly does exhibit some level of the desired biological response. A key point is that an assay is itself an estimator. With this in mind, definitions and a discussion of error rates are given in the context of predictive models. Borrowing from the terminology of signal detection, the sensitivity of a model refers to the fraction of observed hits that are classified as (or predicted to be) hits by the model, and specificity refers to the fraction of observed inactives classified as inactives by the model. An observed hit is not necessarily an active molecule, but simply a molecule for which the primary screening result exceeded a decision threshold. Whether such a molecule turns out to be an active is a problem that involves the sensitivity of the assay, but the task at hand is for... 

This Handbook aims to explain terminology widely used, and sometimes misused, in analytical chemistry. It provides much more information than the definition of each term but it does not explain how to make measurements. Additionally, it does not attempt to provide comprehensive coverage of all terms concerned with chemistry, instrumentation or analytical science. The authors have addressed primarily those terms associated with the quality assurance, validation and reliability of analytical measurements. The Handbook attempts to place each term in context and put over concepts in a way which is useful to analysts in the laboratory, to students and their teachers, and to authors of scientific papers or books. This approach is particularly important because official definitions produced by many international committees and organisations responsible for developing standards are frequently confusing. In a few cases the wording of these definitions completely obscures their meaning from anyone not already familiar with the terms. 

Obviously, Baudelaire s versions both summarize and rephrase De Quincey s text, it is not, therefore, a translation in the conventional sense of the word. However, this passage conforms with Genette s definition of discours transpose , which uses terminology which can be applied to translation ( mimetique , fidelite litterale , transposer , interprete ) ... 

Concepts from many different scientific disciplines are discussed in the different chapters of this book. A glossary of terms is provided to ensure that the terminology associated with each discipline is not an impediment to the reader. Each of the words defined in the Glossary is italicized when it appears in the definition of another word also defined in the Glossary. The definitions are written to present to the reader the essential aspects of a given term in the context in which it was used. These definitions, therefore, are not intended to be comprehensive. 

Ultrafine particles have been defined as those, which are smaller than 0.1 pm. Another classification is into submicrometre particles, which are smaller than 1 pm, and supermicrometre particles, which are larger than 1 pm. The terminology that has been used in the wording of the ambient air quality standards, and also for characterisation of indoor and outdoor particle mass concentrations, includes PM2.5 and PM fractions and the total suspended particulate (TSP). PM2.5 (fine particles) and PM, are the mass concentrations of particles with aerodynamic diameters smaller than 2.5 and 10 pm, respectively (more precisely the definitions specify the inlet cutoffs for which 50% efficiency is obtained for these sizes). TSP is the mass concentration of all particles suspended in the air. There have been references made in the literature to PMj or PMq 1 fractions, which imply mass concentrations of particles smaller than 1 and 0.1 pm, respectively. These terms should be used with caution, as particles below 1 pm, and even more those below 0.1 pm, are more commonly measured in terms of their number rather than their mass concentrations, and therefore these terms could be misleading. 

It is essential to the assessment of safety measures, from a legal as well as from a societal point of view, to have a common understanding of the basic terminology used. Examples are words like hazard or safety. In this context it must be emphasized that the majority of terms expresses probabilities, which are not generally quantifiable. Day to day practice, however, requires certain safety definitions to come up with concrete measures in order to fulfil the promise of safe manufacturing processes. 

An inventory analysis compiles the flows of materials and energy into and out of the system. Necessary work consists of construction of a flow model, data collection, and calculation of results. In other words, the phase of life-cycle inventory (LCI) provides the systems model of the technical system ( product system ) under study, complying with the goal and scope definition. This model consists of certain elements, which in terminology of the ISO standards are the following ... 

We finish this section with a note on the definitions and terminology we will use for the remainder of the book. The term word will always be used for the unambiguous, underlying identity of a word, and never used to indicate its written or spoken form. Words will always be marked in a small caps font. The terms writing, orthography and text are used more... 

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