Basic characterisation tests

Basic characterisation tests that are used to obtain information on the short and long-term leaching behaviour and characteristic properties of materials. 

Compliance tests that are used to determine whether the material complies with specific reference values such as soil screening levels for remediation purposes, or waste acceptance criteria for landfill disposal. These tests focus on key variables and aspects of leaching behaviour identified by basic characterisation tests. 

Verification tests that are used as a rapid check to confirm that the material is the same as that which has been subjected to the compliance tests. 

Multiple batch tests comprise the leaching of a single sample of material sequentially with fresh leachant, to identify the changes in leaching over time rather than the average rate of release of contaminants as in a single batch test. A low liquid to solid ratio (L/S ratio) such as 0.1 or 0.21/kg generally is used for each extraction in multiple batch tests. The low liquid to solid ratio for each extraction is commonly referred to as a bed volume. This is effectively the minimum L/S ratio necessary to conduct a shake test. 

Basic characterisation tests include tests designed to assess the effect of a single variable on the leaching behaviour of a material. Such tests commonly comprise tests to establish the effect of leaching at different pH values and at different redox potentials. 

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Additional characterisation tests are performed to examine the population of data. They do not lead to decisions on whether or not a parameters should be certified or a set of data should be excluded e.g. normality of distribution of means and individual data (Kolmogorov-Smirnov-Lilliefors), consistency between laboratories of variances (Bartlett), etc. Many other tests could be performed before calculating the certified value. No definitive rules are given in the various guides of ISO [1,7]. The basic principle should remain as follows ... 

ANS 16.1 Tank leach test NEN 7345 Swedish MULP Compliance and basic characterisation tank tests are being developed by CEN TC/292 ... 

Dynamic leaching tests for both basic characterisation and compliance tests. 

Incoming raw materials, specifically the matrix constituents and the fibre rovings and mats, should be inspected. Basic inspection includes checking the delivery notes and the labels of containers when the materials arrive. Visual inspection of raw materials is also recommended resins can be inspected for colour and the presence of contamination and gel particles (Evans, 2000) reinforcements can be checked for the presence of knots in the rovings, while simple mass measurements can be made for mats or fabrics. Some pultrusion companies have quality control and/or research and development laboratories where material characterisation tests can be performed (most often such control is executed by raw material suppliers). Fibre reinforcements can be subjected to tensile tests. The moisture content of the constituents (particularly the reinforcements and the fillers) can also be determined. The quality of incoming resins can be tested by means of thermal analysers (resin reactivity) and viscometers (resin viscosity and thixotropic index) (Owens Coming, 2003). 

All such animal procedures suffer from the obvious and basic problem that laboratory animals do not behave like humans and that humans cannot reliably interpret their reactions and behaviour. Thus we know that Parkinson s disease is caused by a degeneration of the dopaminergic nigrostriatal tract but its lesion in animals does not produce any condition which resembles human Parkinsonism, except in primates, even though there are functional tests (e.g. rotational movements) which readily establish that loss of dopamine function and also respond to its augmentation (Chapter 15). By contrast, there are many ways, e.g. electrical stimulation and the administration of certain chemicals, to induce convulsions in animals and a number of effective antiepileptic drugs have been introduced as a result of their ability to control such activity. Indeed there are some tests, as well as animals with varied spontaneous seizures, that are even predictive of particular forms of epilepsy. But then convulsions are a very basic form of activity common to most species and epileptic seizures that are characterised by behavioural rather than motor symptoms are more difficult to reproduce in animals. 

A basic use of a process model is to analyse experimental data and to use this to characterise the process, by assigning numerical values to the important process variables. The model can then also be solved with appropriate numerical data values and the model predictions compared with actual practical results. This procedure is known as simulation and may be used to confirm that the model and the appropriate parameter values are "correct". Simulations, however, can also be used in a predictive manner to test probable behaviour under varying conditions, leading to process optimisation and advanced control strategies. 

Principles and Characteristics A first step in additive analysis is the identification of the matrix. In this respect the objective for most polymer analyses for R D purposes is merely the definition of the most appropriate extraction conditions (solvent choice), whereas in rubber or coatings analysis usually the simultaneous characterisation of the polymeric components and the additives is at stake. In fact, one of the most basic tests to carry out on a rubber sample is to determine the base polymer. Figure 2.1 shows the broad variety of additive containing polymeric matrices. 

Center for Healthcare Technologies at Lawrence Livermore National Laboratory in Livermore, potentially capable to measure pH at or near the stroke site29. The probe is the distal end of a 125 pm fibre tapered up to a diameter of 50 pm. A fluorescent pH-indicator, seminaphthorhodamine-1-carboxylate, is embedded inside a silica sol-gel matrix which is fixed to the fibre tip. Excitation of the dye takes place at 533 nm and the emission in correspondence of the acid (580 nm) and basic (640 nm) bands are separately detected. The use of this ratiometric technique obviates worrying about source fluctuations, which have the same effects on the two detected signals. The pH sensor developed was first characterised in the laboratory, where it showed fast response time (of the order of tens of seconds) and an accuracy of 0.05 pH units, well below the limit of detection necessary for this clinical application (0.1 pH units). The pH sensor was also tested in vivo on rats, by placing the pH sensor in the brain of a Spraque-Dawley rat at a depth of approximately 5 mm30. 

The techniques developed cover various fields, including textural characterisation, elementary and structural analysis and the analysis of composition and surface sites. The book describes the major phases of the technique s development and industrial application, presents its basic concepts and provides a general deKription of industrial equipment, all in a manner that is fully accessible to the non specialist. There is a particular focus on measurement (sample handling, test duration, calibration procedures, etc.) and performance (precision, application limits, possible errors and artefacts), illustrated by concrete examples of catalyst analysis. 

A wide variety of commercial LFIA kits for the detection of antibiotic residues is available and the most well-characterised of these are summarized in Table 5.4, including the rapid one-step assay (ROSA) range from Charm Sciences Inc., and the Tetrasensor, Twinsensor, Trisensor, and Sulfasensor from Unisensor SA and the Betastar from Neogen Corporation. Other LFIA assays have been reported in the scientific literature for the detection of antimicrobial residues, including a lateral-flow device for nicarbazin detection in animal feedstuffs. However, at present these are not commercially available. These LFIA tests incorporate either a receptor protein or an antibody as the specific capture molecule and operate in the competitive assay format (most applicable for small-molecule detection). The sample preparation protocols are based on either direct analysis of the liquid sample (e.g., milk) or a simple extraction step for solid or complex matrices using buffer(s) supplied in the test kit. In general, the time required to perform these tests is less than 30 min with only basic laboratory equipment, if any, required. 

The detailed description of the above methods is not matter of the present paper. The characterisation of the active nature of a catalyst can be split into two main types basic textures of active sites and reactivity tests. In Table 2 a general overview of the methods involved in catalyst characterisation is represented. 

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