THE OXIDATION OF HYDRAZINE. II. THE EFFECT OF OXYGEN ON THE DECOMPOSITION OF HYDRAZINE. THE REACTIONS WITH FERRICYANIDE IN ALKALINE SOLUTION, AND DICHROMATE IN ACID SOLUTION

1924 ◽  
Vol 46 (8) ◽  
pp. 1786-1795 ◽  
Author(s):  
Eustace J. Cuy ◽  
William C. Bray
1926 ◽  
Vol 45 (1) ◽  
pp. 59-70 ◽  
Author(s):  
William Ogilvy Kermack ◽  
William Turner Horace Williamson

Summary1. The rates of sedimentation of a kaolin suspension in presence of varying concentrations of a salt (sodium chloride, potassium chloride, sodium sulphate, di-sodium hydrogen phosphate, sodium citrate, calcium chloride, calcium sulphate, monocalcium phosphate, “superphosphate”, aluminium chloride, ferric chloride or lanthanum chloride) have been compared at various pH values. Abnormal results are obtained with sodium chloride, monocalcium phosphate, aluminium, ferric and lanthanum chlorides.2. Sodium chloride increases the rate of sedimentation in alkaline solution, but actually inhibits it in acid solution.3. In concentrations of monocalcium phosphate above 0·06 per cent, abnormal sedimentation in alkaline solution takes place, with the result that it is much more complete than at the corresponding concentrations in acid solution.4. In acid solution the tervalent ions, aluminium, ferric and lanthanum have little effect, but a zone of very marked flocculation occurs at pH 7–8. This zone separates a region within which the unsedimented particles are negatively charged from a region within which they are positively charged.


Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Fan Zhang ◽  
Jianjian Zhao ◽  
Dawei Hu ◽  
Qian Sheng ◽  
Jianfu Shao

Fluid flow and fluid-rock interaction mainly take place in fracture network, consequently resulting in deformation and permeability variation of rock and deterioration of the wellbore performance. Mechanical-reactive flow coupling creep tests are performed on cracked granite under various confining pressures and acid and alkaline solution flows. The testing results show that the confining pressure and solution pH significantly influence the creep deformation, creep strain rate, and permeability. A primary creep stage and secondary creep stage are observed in all creep tests in this study; notably, the sample under a confining pressure of 10 MPa and acid solution injection undergoes creep failure for over 2700 hours. The acid solution has a more obvious influence on the creep behavior than that of the alkaline solution. With an increase in confining pressure, the total creep strain and creep strain rate in the samples gradually decrease during the injection of either solution. The permeability of the samples injected with either solution gradually deceases during the testing process, and this deceasing rate increases with the confining pressure. The scanning electron microscopy observations on the crack surfaces after the creep tests show that the surfaces of the fractures injected with the acid solution are smooth due to the dissolution of the matrix, while those injected with the alkaline solution include voids due to the dissolution of quartz. These experimental results could improve the understanding of the long-term transport and mechanical behaviors of wellbore.


RSC Advances ◽  
2019 ◽  
Vol 9 (46) ◽  
pp. 26559-26571 ◽  
Author(s):  
Iqbal Ahmad ◽  
Tania Mirza ◽  
Syed Ghulam Musharraf ◽  
Zubair Anwar ◽  
Muhammad Ali Sheraz ◽  
...  

Carboxymethylflavin (CMF) undergoes photolysis in acid solution to form lumichrome (LC) and in alkaline solution, LC and lumiflavin (LF) by side-chain cleavage and β-keto acid and a dioxoquinoxalaine (DQ) compound by isoalloxazine ring cleavage.


1931 ◽  
Vol 5 (5) ◽  
pp. 529-538 ◽  
Author(s):  
A. G. Lochhead ◽  
Leone Farrell

Honey was found to contain an active principle which stimulated fermentation by certain osmophilic yeasts of the genus Zygosaccharomyces in synthetic media. The substance is dialyzable, insoluble in ether and acetone, not precipitated by 85% alcohol, resistant to heating in acid solution and non-volatile. The activating effect of honey is impaired by heating in alkaline solution and by prolonged exposure to moderate dry heat. The active principle may be separated into two fractions by selective adsorption by charcoal. The adsorbed fraction, which may be recovered by elution with alcohol, and the unadsorbed fraction are relatively inert alone, the presence of both being necessary for the active stimulation of fermentation.


1982 ◽  
Vol 28 (4) ◽  
pp. 606-608 ◽  
Author(s):  
Y Hashiguchi ◽  
M Kawaguchi ◽  
M Nakanishi ◽  
Y Matsumori ◽  
Y Kaneda ◽  
...  

Abstract This relatively simple method for quantitative estimation of lipoprotein X is based on assay of phospholipids in precipitates of lipoprotein X. We first remove other lipoproteins by precipitation with phosphotungstic acid solution. Lipoprotein X is then precipitated from the supernatant fluid with an alkaline solution of magnesium ion, and phospholipid is determined in this precipitate. Results are linearly related to concentration of lipoprotein X. The CV is less than 3%. Results correlated well with those for agar gel electrophoresis.


1928 ◽  
Vol 11 (5) ◽  
pp. 613-628 ◽  
Author(s):  
Henry S. Simms

2.5 and 1.25 per cent gelatin have been titrated potentiometrically in the absence of salts and in the presence of two concentrations (0.0750 and 0.0375µ) of NaCl, MgCl2, K2SO4, and MgSO4. The data have been used to calculate values of ± S = vz – (v – 1)z, where vz = v2 – (v2 – v) rx/18. The maximum and minimum values of S with NaCl were used to calculate the mean distance (rx) between like charges in gelatin. This is found to be 18 Å.u. or over (between acid or basic groups) which agrees with the probable value and the titration index dispersion. Thus the data with NaCl are shown to be normal and to obey the equation found to hold for simple weak electrolytes; namely, pK' – pK = Sa See PDF for Equation where S is related to the valence and distance by the above equations. Using the NaCl data as a standard the deviations (ΔS) produced by the other salts are calculated and are found to agree quantitatively with the deviations calculated from equations derived for the simple weak electrolytes. This shows that in gelatin, as in the simple electrolytes, the deviations are related to the "apparent valences" (values which are a function of the true valence and the distance between the groups). The maximum "apparent valences" of gelatin are 2.4 for acid groups (in alkaline solution) and 1.8 for basic groups (in acid solution). These values correspond to the hypothetical condition of zero distance between the groups. They have no physical significance but have a practical utility first as mentioned above, and second in that they may be used in the unmodified Debye-Hückel equation to give the maximum effect of gelatin on the ionic strength. The true effect is probably even lower than these values would indicate. The data indicate that gelatin is a weak polyvalent ampholyte having distant groups and that the molecule has an arborescent structure with interstices permeated by molecules of the solvent and other solutes. The size and shape probably vary with the pH.


RSC Advances ◽  
2014 ◽  
Vol 4 (102) ◽  
pp. 58596-58607 ◽  
Author(s):  
Wen Qian Jiao ◽  
Wen Hua Fu ◽  
Xiao Min Liang ◽  
Yi Meng Wang ◽  
Ming-Yuan He

Hierarchically structured Y zeolites were prepared by a post-synthetic strategy, where the as-made NaY zeolite was sequentially treated by a lactic acid solution and an alkaline solution containing cetyltrimethyl ammonium bromide (CTAB).


2016 ◽  
Vol 39 (4) ◽  
Author(s):  
Nafiseh Zamindar ◽  
Leila Mosaffa ◽  
Moein Bashash ◽  
Mehdi Amoheidari ◽  
Maryam Golabadi

The effect of line, tempering solution, temperature, and soaking time were investigated on water absorption, splitting, and texture of two Iranian red kidney beans including Akhtar and Derakhshan to determine the best line and the best soaking conditions for industrial use. Akhtar line showed higher level of water absorption in comparison to Derakhshan line. Water absorption of unblanched red beans at 2.5 hour soaking was two times greater than water absorption of blanched ones for both lines (p<0.05). Acid solution made texture of Akhtar line softer than samples soaked in water and alkaline solution. In Derakhshan line, shear strength of samples treated with acid solution was lower than alkaline solution and water, respectively. Alkaline solution increased level of splitting in both lines (p<0.05).


1970 ◽  
Vol 48 (8) ◽  
pp. 1323-1332 ◽  
Author(s):  
David J. Stewart ◽  
Osvald Knop

A number of pyrochlore-structure antimonates MSbyOz (M = Na, Ag, K) have been prepared by dry-firing methods. Each M forms a series of compounds which adopt the pyrochlore structure up to a maximum ratio of M:Sb; the ratio depends on M. Antimony in these compounds is usually present simultaneously in trivalent and pentavalent states.The preparation of the above antimonates by wet methods was also examined. The products obtained were found to depend on the pH of the solution. In acid solution a polyantimonate ion exists which on addition of M salts leads to compounds of formula MSb3Oz, while in alkaline solution the Sb(OH)6− ion exists and MSb(OH)6 antimonates are obtained.A previous literature claim that NaSbO3 occurs with the pyrochlore structure has been disproved. It has been shown that NaSbyOz pyrochlore phases exist only for Na:Sb less than 1:1.5.The preparation of antimonates in the presence of Cl− and from hydrated reactants was carried out. It was concluded that neither Cl− nor OH− or H2O play a significant part in causing an antimonate of Na, Ag, or K to adopt the pyrochlore structure.


1994 ◽  
Vol 13 (4) ◽  
pp. 335-338 ◽  
Author(s):  
F. Barba ◽  
P. Ortega ◽  
J. Bermudo ◽  
M.I. Osendi ◽  
J.S. Moya

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