Preliminary investigations

The stability of both Cr species was investigated in different media, different pH and different container materials. By choosing a hydrogen carbonate buffer solution at pH 6.4 as the agent to prevent hydrolysis of Cr(lll), a matrix very close to that of real waters was achieved. Therefore initially an aqueous buffered sample, kept under a CO2 blanket in sealed quartz ampoules, was foreseen. This evolved into lyophilised samples to be reconstituted in the same buffer solution at the right pH. The optimal conditions for lyophilisation avoiding losses of material, and the reduction of Cr(VI) to Cr(Ill), the optimal sample volume and measures to avoid possible adsorption on 

A summary of the results obtained in the interlaboratory study is given in table 8.27. 

For Cr(VI), high results found by some laboratories were attributed to various causes such as e.g. high blank value of the Amberlite LA-2 used for the separation of the Cr species, or inadequate separation. Low values found by other laboratories were suspected to be due to incomplete extraction which was supported by the fact that their Cr(III) value was too high. 

The overall picture revealed that most laboratories had difficulties in determining the Cr(III) content of the A solution. The reason was mainly related to too high detection limits. High values were suspected to be due to contamination problems whereas low 

The determination of the total Cr content in the A solution did not cause many problems. 

The potential for flooding is one of the site characteristics that should be evaluated during both the regional analysis of the site selection phase for a nuclear power plant development project and the site assessment phase, according to the general procedures set out in Ref. [1], 

As the most suitable protection against flooding, the plant should be constructed at a level where it will not be affected by floods. The preliminary evaluation of the flood level is therefore extremely important and should be given due attention in selecting a site. 

At the stage of site selection, it may be evident in certain cases that there is no potential for flooding, because of location or elevation for example. In this case the preliminary assessment should be sufficiently well documented to demonstrate either that the plant would not be affected by any potential flooding or that the potential for flooding is insignificant and has a negligible affect on safety. 

It is not usually practicable to make detailed flood analyses at the site selection stage, and empirical and approximate methods are generally used to estimate roughly the extreme flood. The choice of method will depend on the data available and the characteristics of the region. The results of the 

The reference sites discussed in this Safety Guide pertain to two main 

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As reported before [Ref. 1], there are some essential parameters that influence the results of the testing, such as the thickness of the expired specimen, the quality and coarse grain of the built-in concrete, and the properties of the specimen-surface for the transducer s coupling. At the onset of testings none of tlrese parameters were available. As a result, we had to carry out preliminary investigations in order to prove the applicability of our testing-technique "in situ". 

In other applications of CT, orally administered barium sulfate or a water-soluble iodinated CM is used to opacify the GI tract. Xenon, atomic number 54, exhibits similar x-ray absorption properties to those of iodine. It rapidly diffuses across the blood brain barrier after inhalation to saturate different tissues of brain as a function of its lipid solubility. In preliminary investigations (99), xenon gas inhalation prior to brain CT has provided useful information for evaluations of local cerebral blood flow and cerebral tissue abnormalities. Xenon exhibits an anesthetic effect at high concentrations but otherwise is free of physiological effects because of its nonreactive nature. 

M. Olszewski, Preliminary Investigations of the Thermal Energy Grid Concept, ORNL/TM-5786, Oak Ridge National Laboratory, Oak Ridge, Tennessee, and National Technical Information Service, Springfield, Va., 1977. 

Primary Investigation. The basic systems engineering approach is the most suitable method for developing a solution to industrial wastewater management. The preliminary investigation includes a plant survey and the characterization of the wastewater source. 

Preliminary investigations involving a P-lactam-sensitive, bifimctional D-alanyl-carboxypeptidase—transpeptidase (C Pase—T Pase) from Streptomjces R61 have identified the three-dimensional stmcture and catalytic site of interaction with penicillins (63). 

A-C Preliminary investigation. K-L Review and approval of assembly drawings. 

During a preliminary investigation, much of the expense associated with analytical activities can be reduced by using surrogate or good indicator parameters. These are typically nonspecific. 

Preliminary investigations on the formation of carbenes from diazirines have already been made available. Frey and Stevens recently reported the photolysis of cyclic diazomethane. Cyclic diazomethane was irradiated in the gaseous phase with light of wavelength... 

Vor-untersuchung,/. preliminary investigation, -iirteil, n. prejudice, bias, -vakuum, n. preliminary vacuum, -verbrenmmg, /. precombustion. -verdampfer, m. pre-evaporator. 

If the composition of the bulk material to be sampled is unknown, it is sensible practice to perform a preliminary investigation by collecting a number of samples and determining the analyte of interest. 

The family of uniformly heated round tubes has the simplest heat flux distribution and test-section geometry for which burn-out may occur, and it was selected for the preliminary investigation to test the different sets of important properties. Now, for a uniformly heated tube, the burn-out flux for a given fluid can be represented by the equation... 

Nesmeyanov et a/.545 used a mixture of ferrocene, deuterated trifluoroacetic acid and benzene in the molar ratios 1 2 20 in a preliminary investigation of the reactivity of ferrocene and its derivatives. At 25 °C, rate coefficients were 1,620 x 10-7 (ferrocene) and 19.3 xlO-7 (acetylferrocene). In a subsequent publication by Alikhanov and Shatenshtein543 these values were altered to 1,600 x 10-7 and 1.5 x 10 7, respectively, and a value of 0.77 x 10"7 added for 1,1-diacetylferrocene. Under the same conditions, toluene gave a value of 0.3 x 10-7 so that the activating effects of these compounds relative to benzene can be approximately determined. 

A third mechanism of protodeboronation has been detected in the reaction of benzeneboronic acids with water at pH 2-6.7625. In addition to the acid-catalysed reaction described above, a reaction whose rate depended specifically on the concentration of hydroxide ion was found. In a preliminary investigation with aqueous malonate buffers (pH 6.7) at 90 °C, 2-, 4-, and 2,6-di-methoxybenzeneboronic acids underwent deboronation and followed first-order kinetics. A secondary reaction produced an impurity which catalysed the deboronation, but this was unimportant during the initial portions of the kinetic runs. 

O Connor PG, Barren CK, Rounsaville BJ, et al A preliminary investigation of the management of alcohol dependence with naltrexone by primary care providers. 

Hoechst. 1982. Preliminary investigation of the effect of endosulfan (code, HOE 02671 OI AT 209) on reproduction of the rat. Hoechst Aktiengesellschaft, Frankfurt, Germany. Huntington Research Centre, Cambridgeshire, England. HST 203/82252. [unpublished study]... 

Vissers DR, Tomczuk Z, Steunenberg RK (1974) A preliminary investigation of high temperature Lithium/lron Sulfide secondary cells. J Electrochem Soc 121 665-667... 

A considerable amount of extracellular polysaccharides is produced in the process of cultivation of certain plant suspension cultures and the spent culture medium has proved to be an accessible source for their production (1-3). The interest in investigating these extracellular polysaccharides has been quite strong over the past 10-15 years, motivated by their biological activity (4,5). Plants of the Asteraceae family, as well as their cell cultures, have been established to contain polysaccharides with immunostimulating activity (1-6). The object of our research was Helianthus annuus 1805 cell culture (Asteraceae), which according to the preliminary investigation produces a considerable amount of exopolysaccharides. 

In this paper we attempt a preliminary investigation on the feasibility of catalytic combustion of CO/ H2 mixtures over mixed oxide catalysts and a comparison in this respect of perovskite and hexaaluminate type catalysts The catalysts have been characterized and tested in the combustion of CO, H2 and CH4 (as reference fuel). The catalytic tests have been carried out on powder materials and the results have been scaled up by means of a mathematical model of the catalyst section of the Hybrid Combustor. 

Manley, E. B. (1936). A preliminary investigation into the reaction of the pulp to various filling materials. British Dental Journal, 50, 321-31. 

The present (very preliminary) investigation follows a research line closer to the true spirit of the DFT s, moving in the same direction as some recent papers where the attention is focused on the development of a formalism able to lead to the electron... 

Glennon, R.A. Titeler, M. and Lyon, R.A. A preliminary investigation of the psychoactive agent 4-bromo-2,5-dimethoxyphenethylamine A potential drug of abuse. Pharmacol Biochem Behav. in press. 

Fate. Preliminary investigations directed at adapting the method of Averell and Norris (2) to the analysis of animal tissues indicated that if precautions were taken to avoid emulsions the method could be used satisfactorily. Tissue samples of about 5 grams were most convenient, and the usual reagent and tissue blanks were run simultaneously. Following the administration of an acutely lethal intravenous dose to a dog it was found that parathion could be recovered from the urine, liver, bile, kidney, spleen, and lung. 

Preliminary Investigational Requirements-Petrochemical and Refinery Waste Treatment Facilities, 12020 EID 03/71, Mar. 1971. 

The objective of this work is to study the possible influence of the crude oil composition on the amount of coke deposit and on its ability to undergo in-situ combustion. Thus, the results would provide valuable information not only for numerical simulation of in-situ combustion but also to define better its field of application. With this aim, five crude oils with different compositions were used in specific laboratory tests that were carried out to characterize the evolution of the crude oil composition. During tests carried out in a porous medium representative of a reservoir rock, air injection was stopped to interrupt the reactions. A preliminary investigation has been described previously (8). 

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