Influences of Arsenic on the Analysis of Iron and Steel. III : Determination of Titanium and Molybdenum in Iron and Steel

When titanium was reduced directly by liquid zinc amalgam and titrated with standard ferric solution immediately after the dissolution of steel sample, the presence of 0.15 per cent of arsenic caused about 0.03 per cent high result for titanium. So the removal of arsenic as arsenic tribromide with bromine in hydrochloric acid solution was recommended. In the gravimetric or volumetric determination after the separation of titanium with sodium thiosulfate or ammonium phosphate, there was no interference by arsenic. For the determination of molybdenum in the volumetric method, it was necessary to remove arsenic as tribromide. In the gravimetric method with α-benzoin oxime, however, arsenic had no influence

Electron Diffraction Study on Nickel Surfaces Tarnished in the Course of Heat-Treatment in Hydrogen

When nickel plates for vacuum tubes are annealed in hydrogen gas at 900～1000℃ in the process of production, their surfaces often tarnish and show milk-white appearance, which considerably lowers their commercial value. In order to infer the cause of this tarnishing, six kinds of plates were selected and their surfaces were examined by electron diffraction after heat-treatment. Milk-white surfaces generally gave diffuse rings which were entirely different from the nickel pattern. Three specimens did not alter their appearances after the treatment. One of them gave a few diffuse rings and elongated spots, while the other two, one of which was made in U.S.A., yielded many comparatively sharp rings. According to our analyses, the rings obtained from the two milk-white surfaces were due to (Mg, Ca) SiO_3 and NiO, and those from the two lustrous surfaces beloriged to nickel and Mg_2SiO_4 in one case and to nickel, MnO, MnS and NiO or to nickel, Mg_2SiO_4, MnO and NiO in the other case. From the fact that a greater part of diffraction rings of the milk-white surfaces could be explained as being due to (Mg, Ca) SiO_3, It was concluded that the tarnishing was due to silicates of light metals. Silicates like (Mg, Ca) SiO_3 and Mg_2SiO_4 must be removed during melting, and if a small quantity of them remains and even though disperses over the whole material, it may gradually aggregate in grain boundaries at the heat-treatment, which finally causes the tarnishing of surfaces

Cattle Bile Aggravates Diclofenac Sodium-Induced Small Intestinal Injury in Mice

Cattle bile (CB) has long been used in Japan as an ingredient of digestive medicines. Bile acids are major chemical constituents of CB, and CB ingestion is assumed to affect small intestinal injury induced by nonsteroidal anti-inflammatory drugs (NSAIDs). Mice were fed a diet supplemented with or without CB for 7 days and treated with diclofenac sodium (DIF) to induce small intestinal injury. Lesion formation was enhanced, and PGE2 content and COX expression levels were elevated in the small intestine of DIF-treated mice fed the CB diet compared with those fed the control diet. The administration of a reconstituted mixture of bile acids found in CB enhanced lesion formation in DIF-treated mice. CB administration elevated the contents of CB-derived bile acids in the small intestine, some of which exhibited a high cytotoxicity to cultured intestinal epithelial cells. These results suggest that the elevated levels of CB-derived cytotoxic bile acids in the small intestine contribute to the aggravation of DIF-induced small intestinal injury. The use of CB may be limited during the therapy of inflammatory diseases with NSAIDs

Electron Diffraction Study on Titanium Attacked by Various Acids

Titanium immersed in various acids were examined by electron diffraction. Surfaces attacked by hydrofluoric, hydrochloric, sulphuric or phosphoric acid suffered considerable corrosion and yielded Debye rings of a face-centred cubic lattice, which was deduced as belong to titanium hydride (TiH_2) formed in the course of corrosion. At the surfaces immersed in nitric acid at room temperature for a long period, however, hexagonal rings of titanium alone were observed, and these surfaces were taken as the standard for further corrosion tests. In the following cases the surfaces became passive, and protective films were formed : When the specimens were attacked by boiling nitric acid or aqua regia, anatase was formed, while a mixture of this and a rutile was seen after immersion in boiling 10 per cent solution of chromic acid. The surfaces immersed in boiling 10 per cent solution of ferric chloride for 1 hour yielded many sharp rings, which, however, could not be assigned to any known compound of titanium at the present stage

Influence of Arsenic on the Analysis of Iron and Steel. II : The Determination of Copper and Manganese in Iron and Steel

The influence of arsenic on the determination of copper and mangnese in iron and steel was studied. On the determination of copper, there was no direct influence of arsenic in the sodium thiosulfate separation method and hydrogen sulfide separation method. But in the separating procedure of copper from iron with hydrogen sulfide, the amount of iron coprecipitated with sulfides became larger by the presence of arsenic, and so the reprecipitation of ferric hydroxide was necessary for the perfect separation of copper. It was found also that arsenic had no effect on the determination of manganese by any of the usual methods

Determination of Manganese in Iron, Steel and Ferromanganese. I : Determination of Manganese in Iron and Steel

The suitable concentration of acids and other conditions in ferrous-permanganate method after the oxidation with persulfate were studied for the determination of manganese in Iron and steel and the following results were obtained : (1) Acid concentration : using 2g of ammonium persulfate in total volume of 200ml, manganese was determined in the concentration range 1.2～2.4N sulfuric acid, 0.53～1.20N nitric acid and 0.6～1.2N mixed acid of sulfuric acid and nitric acid (3:1) but manganese could not be determined in acidic solution with perchloric acid. (2) Boiling time : the time of boiling of the solution for the oxidation of manganese by ammonium persulfate using silver nitrate was 5 min, during which the decomposition of permanganic acid occurred. (3) Influence of phosphoric acid : when 1g of iron and 10mg of manganese were present, the existence of 4ml of phosphoric acid (sp. gr. 1.7) was advisable. (4) The suitable procedure for the determination of manganese in iron and steel was established and the analysis was carried out with several samples and reliable results were obtained

Anti-Phase Domains in Gold-Copper-Zinc Ordered Alloys Revealed by Electron Microscope

Using thin evaporated films of gold-copper-zinc ternary ordered alloys, the line-up of anti-phase domains has been observed as parallel lines on transmission electron micrographs of bright field, down to a domain size of about 8A. The lattice modulation accompanying anti-phase domains, i. e. the periodic error of lattice spacing or scattering factor with the same period as a domain size, has again been verified to play an important role in forming the satellites around the direct spot on a diffraction pattern, and hence, in forming the parallel lines on electron-microscopic images. Two-thirds of the intensity of the satellites have been estimated in the present alloy films to arise from the modulation, and the rest probably from double diffraction

Electron Diffraction Study on CuAu at Temperatures Above the Transition Point of Order-Disorder

Using a high temperature electron diffraction camera and thin oriented, evaporated films, the structure of CuAu has been investigated mainly at temperatures above the transition point of order-disorder. When the temperature exceeds the transition point, strong superlattice reflections of CuAu (II) vanish and weak, diffuse maxima appear at superlattice reflection positions, those at {110} positions showing peculiar shape characteristic of anti-phase domains, over the temperature range of about 50℃ above the transition point. It is inferred that short chains of domains with the anti-phase character which is the same as the character in CuAu (II) but much more degenerate than this are present sporadically in the lattice in the equilibrium state in this temperature range