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Table of Contents
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Next: Numerical methods m3b Up: Methods (m3) Previous: Methods (m3)

  
Experimental methods m3a

The modularisation process
The Experimental methods module is certainly feasible, as it is easy to identify and group the information concerning the experimental set-up and the way it is used in measurements. In the linear versions of A05 and A08, the information concerning the experimental methods is predominantly presented in the sections Experimental, which also hardly contain any information of another type. Therefore, the modules Experimental methods A05-m3a and A08-m3a correspond rather closely to the original sections. In the modularisation process, we only had to decide what information to present in a microscopic module, and what to group in a mesoscopic module Experimental methods.

Both the general scheme of the experimental set-up and the individual components are presented at the mesoscopic level. The microscopic modules Experimental methods specify, for example, the size of the slit, the type of atom in the primary beam and the pressure in the collision chamber, which are parameters that vary in the course of the research project.

This module is also concerned with the measurement procedure used to generate experimental results with the set-up. In the domain of biochemistry, for example, measurements are performed following highly standardised protocols, which are explicitly given in journals like Bioorganic & Medicinal Chemistry. In that case, the measurement protocol and the apparatus could be reported in two separate constituent modules. This is not the case in experimental molecular dynamics. In the examples, the accounts of the set-up itself and of the way to use it are intertwined. The information on the way how the set-up is used in measurements is mostly microscopic : what were the pressure and temperature during these particular measurements, how long did the measurements take and how many runs were made?

The resulting module
The sections Experimental in the original versions of A05 and A08 do not make all necessary details available, neither by including them directly, nor by referring explicitly to a publication in which they are given. For example, the original version of A08 mentions a surface-ionisation detector for the measurement of the relative intensity of the primary beam, without providing further details (A08, p.168). In A05 the same or a similar detector is mentioned, and it is specified that the detector consists of a 0.1 mm hot iridium wire and that its efficiency is expected to be energy dependent, which is supported by a reference to an article published in a journal devoted to instrumentation (A05, p.65). The previous articles A03 (A03, p.426) and A04 (A04, p.473) describe in greater detail how the iridium wire had to be treated in order to yield a stable detector, but the two articles give different, complementary details.

In the modular version, we have gathered all information concerning this type of surface ionisation detector in the mesoscopic Experimental methods module MESO-m3a-Ir and made them available to the readers of A05-m3a and A08-m3a by means of a link that expresses the following relations: MESO-m3a-Ir provides a detailed and focused clarification of a particular component of the general set-up of which a particular instance is used in A05-m3a and A08-m3a; furthermore, the mesoscopic module has a wider range than the microscopic modules, and the modules report on the same research project. These explicit links to a complete mesoscopic module make the modular versions of A05 and A08 clearer and more efficient than the linear versions: all details are made available to the readers of the articles, without bogging down the flow of the microscopic modules.

In this particular domain, the set-up consists of standardised components: a source, velocity selection, interaction, analysis and detection. Both in the original and in the modularised version, a schematic overview of the set-up is given. In some of the corpus articles, the structure of the set-up is reflected explicitly in the structure of the text by means of headings, although in A05 and A08 only a few components are thus set apart typographically. The  microscopic modules Experimental methods do not contain constituent modules that represent these components of the molecular beam experiment. Since at the microscopic level the general set-up is only sketched, such constituent modules would not be self-contained. However, we have made the structure of the set-up explicit by means of paragraphs and by linking different components in the graphical representation to their description in the text. The mesoscopic module Experimental methods MESO-m3a, in which a full account is provided, does contain such constituent modules.



Next: Numerical methods m3b Up: Methods (m3) Previous: Methods (m3)