Cleanliness data

There are no official specifications for obtaining a minimum level of engine cleanliness from a fuel. However, all additives in France are subject to approval by the Direction des Carburants (DHYCA), with the objective of having data that prove, first of all, the product to be harmless, and second, the product s effectiveness. Likewise, the automotive manufacturers, in establishing their specifications, set the minimum performance to be obtained by the fuel with regard to engine cleanliness. 

Always check on metallurgy compatibility and cleanliness of the shellside fluid (Data provided by Bos-Hatten and ITT-Standard.)... 

From the above, it would be expected that, except for metal-metal contacts, charging can be very sensitive to the method of contacting and to the surface condition (or state of contamination) of the material. This is, in general, borne out by the seeming contradiction of available data, which are based on widely different methods of contacting and degrees of cleanliness. 

The value of any analysis is judged by the characteristics of the sample as determined by laboratory tests. The sample used for the test(s) must be representative of the bulk material, or data will be produced that are not representative of the material and will be incorrect no matter how accurate or precise the test method. In addition, the type and cleanliness of sample containers are important if the container is contaminated or is made of material that either reacts with the product or is a catalyst, as the test results may be wrong. 

In the first set of measurements the rate of carbon build-up on a Ni(lOO) surface was measured at various temperatures as follows (1) surface cleanliness was established by AES (2) the sample was retracted into the reaction chamber and exposed to several torr of CO for various times at a given temperature (3) after evacuation the sample was transferred to the analysis chamber and (4) the AES spectra of C and Ni were measured. Two features of this study are noteworthy. First, two kinds of carbon forms are evident - a carbidic type which occurs at temperatures < 650 K and a graphite type at temperatures > 650 K. The carbide form saturates at 0.5 monolayers. Second, the carbon formation data from CO disproportionation indicates a rate equivalent to that observed for methane formation in a H2/CO mixture. Therefore, the surface carbon route to product is sufficiently rapid to account for methane production with the assumption that kinetic limitations are not imposed by the hydrogenation of this surface carbon. 

Several elements from the multielement suite are associated with alteration and clay chemistry. Due to the relative cleanliness of the Athabasca Group sandstones, anomalous contents of aluminium, magnesium, potassium, lithium, and boron, along with loss-on-ignition, provide measures of the amount and type of alteration present. These data... 

Many arguments have been adduced for the cleanliness of the metal surface obtained by evaporation (31). In particular, it is found that (a) Robert s heat of adsorption data for W filaments agree with those of Beeck... 

Monthly data shall be collected for each cleanliness class and summarized for the management review. 

In addition, the reliability of the stripping data strongly depends on the degree to which contamination can be minimized. Hence, as in other trace analytical methods, all principles of good laboratory practice (glassware cleanliness, sample collection and storage, etc.) must be observed to obtain high accuracy and low detection limits. 

Continuous automatic air monitoring for multipoints can provide much more information about the environment. Using the statistical analysis of the data obtained by the continuous multipoints monitoring is the best method to monitor the air cleanliness and to take necessary actions before the data exceed an alert level or an action level. The method has many advantages over the data obtained by discrete monitoring methods. 

On the basis of the combined HP-XPS/SFG data, a quantitative analysis of CO coverages at various pressures and temperatures was carried out (253). Figure 27d displays the CO coverage on Pd(l 1 1) as a function of the CO background pressure. It is emphasized again that gas cleanliness is crucial to the success of such experiments. When CO was used as received (purity 99.997%), iron and nickel impurities were detected on the surface, and these caused dissociation of CO and produced various carbon species (cf. Fig. 13d) (253). 

In this report, these concepts are applied to real proteins to collagen, an important structural material in tendons, bones, teeth, and skin, and to gelatin, the denatured product of collagen that is so important industrially. These materials are complex because of their 18 different, component amino acid side chains in addition, they present experimental difficulties because of their water solubility— they cannot be washed (e.g., with an aqueous detergent) to assure surface cleanliness. Furthermore, they are often of unknown purity. They do have the common polyamide backbone, and it is possible to transform the molecular configuration. The data are indicative of the potential utility of contact angle measurements of important, natural materials. No claim is made for adequate attention to the complex biochemistry of these materials. 

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