Aggregation, performance characteristics

Among organic constituent measurements, that of aggregate properties (BOD and COD) and specific parameters (TOC for example) has been well developed for more than 20 years. Concerning BOD, a recent review on biosensors [33] has been published. BOD biofilm-based sensors as well as respirometric systems, other measuring principles, and the commercial BOD instruments are discussed and compared regarding their performance characteristics like linearity, response time, precision, agreement between BOD values obtained from the biosensors and the conventional 5-day test, as well as toxic resistance to various compounds and operational stability. 

The tinting strength of rubber-grade carbon blacks shows a linear relationship with D s shown in Figure 5. Since performance characteristics are known to depend on aggregate volume, surface area, and bulkiness, it appears that the D s values combine the effects of all these factors. As such, it is a valuable addition to carbon black characterization methodology. 

Several performance characteristics of rubber such as abrasion resistance, pendulum rebound, Mooney viscosity, modulus, Taber die swell, and rheological properties can be modeled by Eq 7.34. " A complex mathematical model, called links-nodes-blobs was also developed and experimentally tested to express the properties of a filled rubber network system. Blobs are the filler aggregates, nodes are crosslinks and links are interconnecting chains. The model not only allows for... 

Multicriteria decision making is feasible in two ways. First, the different performance characteristics are aggregated to an objective function, most easily by a weighted sum. The objective function, Z, is obtained from the p individual objective criteria, z,-, by... 

Table 4.2 Aggregation of performance characteristics to an objective function (explanation in text).

The weights are adjusted in such a way that they reflect the real influence of the performance characteristics on the total result. This is not usually easy to do. In addition, with this method, the type of aggregation has to be decided in advance and optimization is carried out with respect to a single point. 

The sweep test (ASTM D 7000 2011) can also be used to measure the performance characteristics of bituminous emulsion and aggregates by simulating the brooming of a surface dressing in the laboratory. 

The role of a surfactant in emulsion polymerisation may vary during the course of the polymerisation. Initially the surfactant contributes to the rate of polymerisation and particle formation. Once polymer is present the surfactant has to solubilise the polymer preventing precipitation and when polymerisation is complete the surfactant is required to stabilise the emulsion preventing flocculation of the polymer and the formatir. . of aggregates. Where the product is utilised in latex form the surfactant plays a major part in the performance characteristics and in particular in the areas of ... 

Some end-use applications may prefer the characteristics of foundry solid waste. For instance, spent foundry sand is a uniformly graded fine aggregate containing chemically active iron and organics. Spent foundry sand can be superior to other types of granular materials, such as compacted soils or clays, for hydraulic barriers. In this case, spent foundry sand provides better performance at lower cost. 

Despite the fact that many different cationic lipids have been synthesized and tested for transfection (25 34), relatively few systematic structure activity TE-relationship studies have been performed (35 39). As a result, no general relationship between chemical structure and TE could be drawn from these studies. One reason for this is that the chemical structure of a cationic lipid is not directly responsible for TE. TE rather depends on the biophysical characteristics of the cationic lipid aggregate (e.g., liposomes and lipoplexes), which, for its part, is dependent on the chemical structure of the lipids. In a previous study with analogs of the transfection lipid A-[l-(2,3-dioleoyloxy) propyl]-A,A,A-trimethylammoniumchloride (DOTAP) (40) which differ in their nonpolar hydrocarbon chains, it could be shown that the TE strongly depended on the biophysical properties of the resulting liposomes and lipoplexes (35). Minimal alterations of biophysical properties by using lipids with different hydrocarbon chains or by mixing the lipid with different neutral helper lipids could completely allow or prevent transfection. 

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