Composite type record

Aylsworth (97) was the first person known to invent an IPN. In 1914 he combined the then new phenol-formaldehyde compositions with natural rubber and sulfur. Of some historical interest is that Jonas Aylsworth was Thomas Edison s chief chemist (110). Edison had just switched from the cylinder-type record to the platter, using the new phenol-formaldehyde materials. However, these phenol-formaldehyde materials were brittle, and the first phonograph records had to be made very thick to prevent breakage. 

A composite type represents a collection of objects that are defined as either composite types or scalar types. These objects can be organized in two ways as an array or as a record. The objects in a composite type caimot be defined as either access or file types if the type is to be synthesized. 

A record can consist of any synthesizeable scalar or composite type. It is declared using the syntax type dedaratfon... 

An object mtist be declared to be certain type. Integer and enumeration types are available. These can be formed from a single element - a scalar type - or multiple elements - a composite type. A composite type can be organized as an array or a record. 

It is rare to be able to observe elastic deformations (which occur for instance during earthquakes) since by definition an elastic deformation does not leave any record. However, many subsurface or surface features are related to the other two modes of deformation. The composition of the material, confining pressure, rate of deformation and temperature determine which type of deformation will be initiated. 

Your process may produce wastes that cannot be treated on-site, and so must be transported off-site for treatment and disposal. Wastes of this type are usually non-aqueous liquids, sludge, or solids. Often, wastes for off-site disposal are costly to transport and to treat, and represent a third-party liability. Therefore, minimization of these wastes yields a direct cost benefit, both present and future. Measure the quantity and note the composition of any wastes associated with your process that need to be sent for off-site disposal. Record your results in a table or an appropriate spreadsheet. 

The type of plate, chamber system, composition of mobile phase, running time and detection reagent used must naturally all be recorded The sample protocol illustrated in Figure 62 can be employed... 

Both positive and negative ions are produced during the sputtering process, and either can be recorded by an appropriate choice of instrumental parameters. Positive ions are the result of protonation, [M + H]", or cationiz-ation, [M +cation], whereas negative ions are preponderantly [M-H], but can also be formed by the addition of an anion, that is, [M+anion]". The type of pseudomolecular ion produced is governed by the chemical nature of the sample and by the composition of the matrix from which it is ionized. 

For studies involving test substance application to soil, there may be a requirement for more soil information than for studies where applications are made to foliage of established crops. The study protocol should describe any specific requirements relative to soil type selection and how to confirm the soil characteristics for the study. Most studies simply require that the soil be identified by its name (e.g., Keystone silt loam) and composition (e.g., percent sand, silt, and clay). This information can typically be acquired from farm records, a soil survey of the local area, or a typical soil analysis by a local soil analysis laboratory. In some instances, a GLP compliant soil analysis must be completed. The study protocol must clearly define what is needed and how it is to be obtained. Unless specified in the protocol, non-GLP sources are adequate to identify the soil and its characteristics. The source of the soil information should be identified in the field trial record. 

Tables 6.27 and 6.31 show the main characteristics of ToF-MS. ToF-MS shows an optimum combination of resolution and sensitivity. ToF-MS instruments provide up to 40000 spectra s-1, a mass range exceeding 100000 (in principle unlimited), a resolution of 5000, and peak widths as short as 200 ms. This is better than quadruples and most ion traps can handle. Unlike the quadrupole-type instrument, the detector is detecting every introduced ion (high duty factor). This leads to a 20- to 100-times increase in sensitivity, compared to QMS used in scan mode. The mass range increases quadratically with the time range that is recorded. Only the ion source and detector impose the limits on the mass range. Mass accuracy in ToF-MS is sufficient to gain access to the elemental composition of a molecule. A single point is sufficient for the mass calibration of the instrument. ToF mass spectra are commonly calibrated using two known species, aluminium (27 Da) and coronene (300 Da). ToF is well established in combination with quite different ion sources like in SIMS, MALDI and ESI.

Whenever a test 1s to be run, the sample composition and Instrument control parameters must be defined. This Is done with three (or more) data-entry screens. The first data-entry screen, shown In Figure 4, deals with experiment identification and base fluid composition. The operator simply types in the desired information Into unprotected fields of the screen. Information requested Includes such Items as experiment ID, submitter s name, base fluid type and base fluid additives. The base fluid pump rate and valve selection are also requested for later use by the control programs. The second data-entry screen is used to select the desired test temperatures and also to record any comments related to the experiment. The third data-entry screen Is used to input the in-line additive compositions. This screen is filled out for each set of additives to be tested with the base fluid as described on Data-Entry Screen No. 1. Also input are the pump rates for each of the three additive pumps. This information is used by the control programs when the additive set is being tested. (The pump rates are preset by the operator, but the pumps are turned on and off by the control programs as necessary during the course of an experiment.)... 

Before nitrates and particularly ammonium nitrate were readily available commercially, explosives were developed based on chlorates and perchlorates. These also are still used in some countries. In general perchlorates are considered less dangerous than chlorates and therefore preferred. They are easily sensitised, so that in addition to explosives of this type based on nitroglycerine, others have been based on various organic liquids, particularly nitrobodies. History shows that chlorates and perchlorates must be regarded as temperamental substances, liable in bulk to lead to inexplicable accidents. Particularly when mixtures of chlorates and oxidising materials are allowed to become wet and then dry out, conditions can arise in which there is an appreciable sensitiveness to friction and impact. Explosives of this type have an unfortunate record of accidents. They are used, therefore, to a limited extent only, now that safer compositions are available. 

Quite often a normal electron ionization mass spectrum appears insufficient for reliable analyte identification. In this case additional mass spectral possibilities may be engaged. For example, the absence of the molecular ion peak in the electron ionization spectrum may require recording another type of mass spectrum of this analyte by means of soft ionization (chemical ionization, field ionization). The problem of impurities interfering with the spectra recorded via a direct inlet system may be resolved using GC/MS techniques. The value of high resolution mass spectrometry is obvious as the information on the elemental composition of the molecular and fragment ions is of primary importance. 

The adduct formation can be largely controlled and directed into the formation of a single selected species by adequate choice of the ionisation mode (possibly at the expense of sensitivity), the eluent composition (buffer addition, pH adjustment, type of organic modifier) and by optimisation of the ion source parameters influencing the stability of individual (adduct) ions. In contrast to the variations in adduct or cluster formation, which principally can be diagnosed by recording more than one (adduct) ion in SIM mode, the occurrence of ion suppression requires more careful diagnosis. 

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