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1.
A.Y. El-Etre 《Applied Surface Science》2006,252(24):8521-8525
The inhibitive effect of the extract of khillah (Ammi visnaga) seeds, on the corrosion of SX 316 steel in HCl solution was determined using weight loss measurements as well as potentiostatic technique. It was found that the presence of the extract reduces markedly the corrosion rate of steel in the acid solution. The inhibition efficiency increases as the extract concentration is increased. The inhibitive effect of khillah extract was discussed on the basis of adsorption of its components on the metal surface. Negative values were calculated for the energy of adsorption indicating the spontaneity of the adsorption process. The formation of insoluble complexes as a result of interaction between iron cations and khellin, which present in the extract, was also discussed. 相似文献
2.
T. Drglin 《Accreditation and quality assurance》2003,8(3-4):130-133
A validation procedure based on the ISO/IEC 17025 standard was used to demonstrate the long-term stability of a calibration
process and to assess the measurement uncertainty of a standard test method for optical emission vacuum spectrometric analysis
of carbon and low-alloy steel (ASTM E 415–99a). The validation was used to provide documented evidence that the selected method
fulfils the requirements and that the method is ”fit for purpose”. A test for drift was applied to determine statistically
whether the analytical results vary systematically with time. The accuracy and traceability of the optimised method were tested
by an analysis of closely matched matrix certified reference materials (CRMs). The measurement uncertainty estimations took
account of the precision study, the bias and its uncertainty, and the qualification of uncertainties not considered in the
overall performance studies.
Received: 2 November 2002 Accepted: 2 January 2003
Acknowledgement The author expresses gratitude to Dr. Aleš Fajgelj for helpful discussions during the 3rd Central European Conference on Reference Materials and Measurements.
Presented at CERMM-3, Central European Reference Materials and Measurements Conference: The function of reference materials
in the measurement process, May 30–June 1, 2002, Rogaška Slatina, Slovenia
Correspondence to T. Drglin 相似文献
3.
本文介绍概率抽样法在钢球生产过程中的应用,通过此法确定钢球生产中各工序质量监测的最佳抽检方案,以确保产品被接受的概率最大。 相似文献
4.
A coulometric method was developed for the determination of microamounts of sulphur in iron and steel. Hydrogen sulphide is quantitatively evolved by reduction with iron(II) in strong phosphoric acid medium and is titrated with electrolytically generated silver ion from a silver anode. Microamounts of sulphide (2.96–224.3 μg) in sodium sulphide standard solutions could be determined with an error of only a few percent. Sulphur in a potassium sulphate standard solution is quantitatively reduced to hydrogen sulphide and could be separated from the solution by heating and determined accurately. Trace amounts of sulphur (7–100 μg g?1) in iron and steels could be determined with a standard deviation of 0.7–2.1 μg g?1. 相似文献
5.
Extraction-spectrophotometric determination of iron with 2-(2′-benzothiazolylazo)-4,6-dimethylphenol
Pérez Pont M. L. Sánchez M. J. Francisco A. García Montelongo F. 《Mikrochimica acta》1986,88(3-4):183-190
An extraction-spectrophotometric method for the determination of trace amounts of iron based on its extraction into chloroform with 2-(2-benzothiazolylazo)-4,6-dimethylphenol (BTADMP) from a pH 6.5 medium has been developed. The extracted 12 FeBTADMP complex species allow the determination of 4–30gmg of iron (=3.92×1041·mol–1·cm–1 at 790 nm). The method is highly selective and has been applied to the determination of iron in polymineral-polyvitamin pharmaceutical products. 相似文献
6.
The way to measure quantitatively full dissolution and crystallization of polyamides in water up to 200 °C and above by DSC is described. Stainless-steel high-pressure pans enable research on fully dissolving polyamides in water under vapor pressure. The results show clearly that polyamide 6 (PA6) is soluble in water under vapor pressure in the whole concentration range and that water acts as a crystallization and melting point suppressor. The maximum temperature depression is approximately 60 °C. This depression of the transitions is independent of concentration over a large range (10-70 mass% PA6 in water). When PA6 dissolves in water during heating, the polymer often sets to the sides of the DSC sample pan. Because of this the contact between the sample and the bottom of the pan reduces during measurement and therefore DSC heating curves are frequently curved. Adding steel wool to these stainless-steel high-pressure pans improves the measurements by increasing the thermal conductivity between the sample and pan bottom, and as a result the DSC curves become less curved. The interpretation of the measurements improves and the possibility of reproducible peak area calculations also in heating comes in sight. 相似文献
7.
T. Jeanmaire C. Brondino Y. Hervaud B. Boutevin 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2331-2343
Ce mémoire décrit la synthèse de phosphonates comportant une chaîne perfluorée. Ces composés sont obtenus par la télomérisation d'allylphosphonates de dialkyle en présence d'un agent de transfert fluoré de type mercaptan. Ensuite, nous employons deux méthodes de déalkylation menant sélectivement soit au monoacide soit au diacide phosphonique. Tous ces produits comprenant une extrémité de chaîne phosphonée, sous forme acide ou ester, ont été caractérisés et leur adhésion respective sur des plaques d'acier est étudiée. Ces tests montrent que le monoacide phosphonique est un excellent promoteur d'adhésion et qu'il est aussi efficace que le diacide. This article describes the synthesis of phosphonic derivatives bearing a perfluorinated chain. These compounds have been synthetized by telomerization of dialkyl allylphosphonate with a fluorinated transfer agent type mercaptan. Then two methods of dealkylation leading selectively were used to mono or to diacid phosphonic moieties. All the products bearing phosphonic end-groups, more or less acidic, have been characterized and their own adhesion on steel plates is studied. These tests show that phosphonic monoacid is an excellent adhesion promoter on steel, as efficient as the diacid compound. 相似文献
8.
9.
Ferritic/martensitic (F/M) steels are good candidate structural materials for the future fusion reactors and spallation sources. However, irradiation of steels is known to produce hardening, loss of ductility, shift in ductile to brittle transition temperature (DBTT) and reduction of fracture toughness and creep resistance starting at low doses. Helium (He), produced by transmutation during the irradiation, also impacts mechanical properties. Numerous experimental and theoretical studies on the evolution of the microstructure of steels under irradiation have been conducted until now. We review the effect of irradiation-induced point defects and in particular of He on the mechanical properties of F/M steels. To cite this article: R. Schäublin et al., C. R. Physique 9 (2008). 相似文献
10.