摘要:

AbstractSyntheses suitable for large laboratory‐scale working, are described for thiocytosine, cytosine, 4‐hydroxypyrimidinc, 4‐amino‐pyrimidine, 2 : 4‐ and 4: 6‐diaminopyrimidincs, uracil, 4‐amino‐6‐hydroxypyrunidineand several of their derivatives. The majority of these syntheses start from thiouracil, which has recently become plentiful; all involve replacement of a thiol‐grou

ISSN:0368-4075    

DOI:10.1002/jctb.5000691201

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe corrosion of mild steel by sea‐water/distilled water mixtures at 25° or 60° c. can be completely inhibited by the presence of 3 percentage (w/v) of sodium nitrite greater than 1,5 of the sea‐water percentage (v/v). Similar sodium nitrite additions inhibit the corrosion of white metal by such waters and decrease the corrosion of copper (especially at 60°c. indicate they have no appreciable influence on the corrosion of brass at 25° c. Corrosion‐potential measurements at 25°c. indicate that nitrite is an anodic inhibitor. These and other results suggest that its main action is the oxidation of ferrous compounds to ferric, stannous to stannic, and cuprous to cupric, with a concomitant rise in pH, so that the very sparingly soluble higher oxides or hydrous oxides arc readily precipitated at anodic places and stifle

ISSN:0368-4075    

DOI:10.1002/jctb.5000691202

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe solubility of lead in zinc sulphate solutions was determined over the range of zinc concentration from 75 to 125 g./l., acid concentrations from OT to 75 g./l., and temperatures of 20°‐30° c. In this range of variables normally encountered in electrolytic zinc refineries the lead solubility varied from 4.3 to 6.8 mg./l. It decreased with increase in acid concentration, increased with increase of temperature, and was nearly unaffected by zinc concentrat

ISSN:0368-4075    

DOI:10.1002/jctb.5000691203

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractA large number of substances were tested for ability to destroy the foam on four(different foaming aqueous solutions. The ability or inability of the anti‐foams to spread on the foaming liquid was also studied.It is concluded that anti‐foams act by displacing from the surface the substance causing the foaming (or, in salt solutions, preventing negative adsorption). They may do this either by dissolving in the foam liquid or bespreading over its surface.) The causes of the strong, correlation (found) between foam‐killing and spreading are disc

ISSN:0368-4075    

DOI:10.1002/jctb.5000691204

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe mechanisms controlling the volume of foam formed by air bubbling continously through a liquid have been studied. Examples are given in which one—coalescence of bubbles within the foam— or another—bursting of bubblos at the top of the foam—predominates. The effect of alcohols in enhancing foaming, as well as in destroying foam is noted. The effect of the gm flow rate on foam volume has bed investigated and is found to differs from liquid to liquid. No simple relation between the two exists In the present state of our knowledge the foam volume under‐&given circumstances an be found only by e

ISSN:0368-4075    

DOI:10.1002/jctb.5000691205

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe cathodic character of painted or otherwise partially screened steel in sea‐water is explained by the retention behind the pint‐film of the products of reaction of local corrosion couples. Local anodes behind the film will be suppressed by accumulation of ferrous ions. Alkalinity produced at local cathodes renders the steel passive and so encourages passage of further current in the same direction.Experiments are described showing that an iron electrode transferred from neutral to alkaline salt solution becomes temporarily anodic, then quickly becomes cathodic as passivity devel

ISSN:0368-4075    

DOI:10.1002/jctb.5000691206

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractA range of five solids, of widely‐varying physical properties, were fluidized, as powders, by 3 heated air stream. Rates of heat transfer to a cooling coil increased in the fluidized media were measured. It is shown the hear‐transfer coefficients obtained are relatively independent of the solid conductivities, and appear to vary as the product of (surface per unit volume of the fluidized solid) and (conductivity of static powdered material). The results are compared with those published recently by other work

ISSN:0368-4075    

DOI:10.1002/jctb.5000691207

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractA new form of water‐flow gas calorimeter is described in which gas volumes are read with a soap‐film meter, and water volumes on a burete. The calorimeter is a silvered and evacuated resistance‐glass vessel. A new type of pump is used to supply air to the burner. The gross calorific value of a gas can be obtained in to minutes if the rates of flow of air, gas and water arc set correctly. The calorimeter was designed to give results correct to the nearest I3.Th.U. but an accuracy greater than this may he pos

ISSN:0368-4075    

DOI:10.1002/jctb.5000691208

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractIn various experiments in these laboratories it has become necessary to consider the effect on the energy dissipated in friction of a force acting normally to the direction of the flow‐path of a liquid. It appeared that such a case was analogous to that of a liquid constrained to flow in a coiled tube, wherein the energy dissipation is higher than in a straight tube of the same length and bore; and furthermore in the curved path a type of streamline motion persists to Reynolds' numbers which arc far greater than the lower limit of turbulence in a straight tube. The experiments described were carried out to test this analog

ISSN:0368-4075    

DOI:10.1002/jctb.5000691209

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

ISSN:0368-4075    

DOI:10.1002/jctb.5000691210

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY