bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raney cobalt hydrogenation catalysts. III. Applications and promoter effects
Authors: Aller B. V. 
Published: July 2010

AbstractA description is given of the use of Raney cobalt for the hydrogenation of unsaturated and carbonyl linkages under mild conditions. The results are compared with those obtained with Raney nickel catalysts.A study has also been made of the promoter effects of triethylamine, chloroplatinic acid and combinations of these, on the activity of the Raney cobalt catalyst for the hydrogenation of carbonyl compounds. As in the case of Raney nickel, such effects are highly specific for the compound under investigation. The most notable effect occurred in the hydrogenation of benzaldehyde, where the use of triethylamine chloroplatinate as promoter resulted in a cobalt catalyst having an activity several times greater than an unpromoted catalyst.
The dealkylation of alkyl aromatic hydrocarbons. III. The dealkylation of polynuclear aromatics
Authors: Betts W. D. , Popper F. 
Published: July 2010

AbstractThe studies of thermal dealkylation1, 2 have been extended to the polycyclic hydrocarbons. In the temperature interval of 560 to 660°, at a pressure of 100 atm. and with a large excess of hydrogen, α‐ and β‐methylnaphthalene, a methylnaphthalene oil and a number of coal‐tar fractions were studied. On the assumption of the same mechanism as for toluene dealkylation1 the results were fitted to a 1.5‐order reaction mechanism. The energies of activation for α‐ and β‐methylnaphthalenes agree well with the proposed mechanism.Naphthalene oils of coke‐oven origin should be capable of giving quantitative yields of naphthalene. Oils of vertical‐retort origin are too rich in paraffin content. Little dealkylation was obtained with a coke‐oven anthracene oil.
Low‐temperature explosions of mixtures of potassium perchlorate with some combustible substances
Authors: Grodzinski J. 
Published: July 2010

AbstractMixtures of potassium perchlorate with some combustible substances have been heated in sealed test‐tubes and their ‘explosion temperatures’, time‐lag' of explosion and ‘critical’ mass/volume ratio ‘determined’. The relation between the explosion temperature and the chemical character of the substance mixed with potassium perchlorate was investigated. Influence of other factors on the ‘explosion temperature’ and on the ‘time lag’ of explosion was also examined.The possible mechanism of the observed low‐temperature explosions has been discussed.
Zinc Alloy Anodes
Authors: Crennell J. T. , Wheeler W. C. G. 
Published: July 2010

AbstractLaboratory and full‐scale trials of zinc anodes have shown that the presence of small amounts of aluminium (0.5–1.0%) gives improved performance and that addition also of 0.25–0.5% of silicon is more effective. The detrimental effect of iron is overcome by these additions.
Fractionation studies on the proteins of the groundnut (arachis hypogaea)
Authors: Naismith W. E. F. , Mcdavid Helen M. R. 
Published: July 2010

AbstractAttempts to prepare pure samples of the conarachin I and II fractions of groundnut protein by fractional precipitation are described. Although pure conarachin I has been prepared, all attempts to purify conarachin II have so far been unsuccessful. Methods for isolating pure arachin without the use of ammonium sulphate are also outlined. It has been shown that the precipitation limits of a protein with ammonium sulphate are modified by the presence of other proteins.
The determination of trace elements in pulverized‐fuel ash
Authors: Smith A. C. 
Published: July 2010

AbstractIn connexion with work on the utilization of pulverized‐fuel ash, spectrographic methods are described for the determination of 30 trace elements.Determinations of these elements in 18 ashes were carried out, but none was present in concentrations sufficient for economic recovery. Apart from titanium, where the concentration is of the order of 1%, only manganese exceeds 0.mD1%, while copper, lead, zinc, nickel and chromium fall in the range 0.mD01–0.mD1%. Concentrations of other elements are much below 0.mD01%, while thallium, cadmium, mercury, rubidium, tungsten, silver, zirconium, platinum, indium, palladium, lanthanum and gold were not detected.
The microstructures of some amatols
Authors: Williamson W. O. 
Published: July 2010

AbstractFusion‐cast amatols contained ammonium nitrate grains included in TNT crystals. Some TNT crystals were prisms elongated on [c] and approximately perpendicular to the wall of the mould. Ammonium nitrate grains were mono‐ or poly‐crystalline and some showed evidence of aggregation prior to incorporation with fused TNT; aggregation during fusion casting was rarely indicated. Segregation of the grains by pressure from growing TNT prisms was seen in a few castings unusually poor in ammonium nitrate.At least some proportion of added wax appeared as segregations in TNT. Added aluminium grains were found in or between TNT crystals. Parallel layers of ammonium nitrate and TNT occurred in parts of test‐pieces of pressed amatol.Completely fused mixtures of TNT with eutectic proportions of ammonium, calcium and sodium nitrates, were simple or multiple emulsions; the structures of these emulsions became ‘frozen’ when the melt solidified.
Effects of additives on ignition delay of the system, white fuming nitric acid ‐ turpentine
Authors: Makovky A. , Salmon A. 
Published: July 2010

AbstractThe ignition delay of turpentine is not affected by the proportion of oxidizing agent added. The delay is reduced by addition to the nitric acid of oleum up to a certain concentration or by addition of catalysts in the order Fe Cl3 > NH4VO3 > Cu Cl2, but is increased by dilution with petroleum.
Reactivity of lime and related oxides. III. Sorption of liquid water on calcium oxide (‘wet’ hydration)
Authors: Glasson D. R. 
Published: July 2010

AbstractCalcium oxide samples differing widely in surface activity (5–100m.2 g.‐1) have been ‘wet’ hydrated at room temperature using water, pure or diluted with acetone as an inert liquid.Rates of hydration and changes in surface area and lattice structure indicate that ‘wet’ hydration proceeds by a mechanism similar to that found earlier for ‘dry’ hydration by water vapour, i.e., hydration proceeds inwards from the outside of each calcium oxide particle by an advancing interface mechanism. In each case, the more active limes become aged (agglomerated) rapidly, but when the less active limes are ‘wet’ hydrated the number of crystallites generally increases much more than for ‘dry’ hydration; cleavage of the calcium hydroxide formed on the surface of the oxide is therefore more extensive, in keeping with the faster hydration. Slow ‘wet’ hydrations using 1% water more closely resemble ‘dry’ hydrations in that the number of crystallites increases only over their later stages. Ultimately, all the ‘wet’ hydrated samples age on prolonged contact with water, their crystallite growth showing some relationship to that of calcium hydroxide precipitated from solution by double decomposition.
Adsorption of methylene blue in the determination of surface areas
Authors: Kipling J. J. , Wilson R. B. 
Published: July 2010

AbstractData are presented for adsorption of methylene blue from aqueous solutions on two non‐porous carbons and on a porous activated charcoal. From the specific surface areas of the non‐porous carbons (determined by low‐temperature adsorption of nitrogen) it is calculated that the adsorbed methylene blue occupies an area of between 102 and 108 sq. Å/molecule. These values are compared with those derived from a structural model and with those reported in the literature. It is concluded that this type of adsorption cannot yet be used for accurate determination of surface areas of carbons, nor can it give more than semi‐quantitative information when used as a ‘molecular probe’ to investigate the pore structure of porous charcoals.
Combustion of fuel in the bomb calorimeter as indicated by changes in the pressure system. II
Authors: Patterson W. S. , Parr‐Burman H. B. A. 
Published: July 2010

AbstractResults are recorded for the combustion behaviour (rate of combustion and maximum pressure pressure developed) in the bomb calorimeter of peat and coal samples of different rank. The effects on combustion behaviour are determined for cokes obtained at various carbonisation temperatures and of different reactivities (as determined by the C.A.B. test), for carbon blacks of different particle sizes, and for peat of various moisture contents, are examined and discussed.
Krypton adsorption and the surface area of silica
Authors: Sing K. S. W. , Swallow D. 
Published: July 2010

AbstractDetails are given of the apparatus used for measuring adsorption isotherms of krypton at −196°, which allowed a rapid and precise measurement of pressure.Surface areas have been calculated, by the B.E.T. method, from the krypton adsorption isotherms on samples of ground quartz and a silica gel. The surface areas of the quartz samples determined by other workers, using B.E.T. nitrogen adsorption and electron microscopy, agreed well with the krypton values, provided that the atomic cross‐sectional area of krypton was taken as 19·5Ǎ2.It was not possible to obtain a ‘standard’ curve from the krypton adsorption isotherms on the non‐porous silicas, but when these isotherms were plotted in logarithmic form, all gave a substantial linear region with the same slope. The logarithmic plot of the isotherm on the silica gel had a different slope; it would seem likely, therefore, that capillary condensation occurred on this sample at low pressure and that the B.E.T. area is invalid here.
X‐ray scattering intensities of coals treated with lithium in ethylenediamine
Authors: Ergun S. , Wender I. 
Published: July 2010

AbstractX‐ray scattering intensities have been obtained of seven vitrinites of different rank and a natural graphite before and after treatment with lithium in ethylenediamine. Scattering intensities showed extensive changes in the arrangement of carbon atoms. The major apparent change occurred at low and moderately low scattering angles. The peaks attributed to parallel packing of aromatic layers were displaced to lower angles corresponding to increase in d‐spacings from about 3·6 to 4·6Å. These findings suggest that conversion of planar aromatic layers to buckled hydrogenated rings has occurred. Graphite was partly hydrogenated and showed a distinct new peak at a d‐spacing of 4·8Å, in addition to the (002) peak at 3·35Å.The treated vitrinites showed less small‐angle scattering, the decrease probably being caused by expansion of the layers at the expense of small pores, that is, inhomogeneities. For medium‐ and high‐rank coals, the scattering intensities at high angles showed only minor changes consistent with conversion of aromatic to alicyclic structures and not to open chain structures.
Catalytic hydrogenation of sugars
Authors: Boelhouwer C. , Korf D. , Waterman H. I. 
Published: July 2010

AbstractIn a number of comparative hydrogenation experiments with sucrose as a raw material it is demonstrated that high yields (up to 75%) of distillable polyalcohols (mainly glycerol and 1,2‐propanediol) can be obtained at moderate temperatures (200‐250°) with copper chromite catalysts activated with beryllium oxide. Nickel catalysts are active even at still lower temperatures, especially in the presence of Ca(OH)2; thus 70% of distillable polyalcohols were obtained by hydrogenating sucrose in methanol in the presence of 3·5 wt.‐% of Ca(OH)2 and 15% of a nickel‐onkieselguhr catalyst during 105 min. at 195°.The product distribution analysis according to Weber allowed an easy comparison of the experimental results, particularly in regard to the selectivity of the applied catalysts.
Weathering of road tar in open‐textured surfacings
Authors: Tingle E. D. , Wright N. 
Published: July 2010

AbstractExperiments are described in which tars have been oxidised in the laboratory under controlled conditions, or weathered in tarmacadam on the road. The tars were analysed at intervals during the oxidation and during the weathering, into fractions according to solubility in a series of solvents of increasing solvent power. Changes in the value of the ratio of certain of the resin fractions have been used for estimating the contribution of oxidation to the hardening of tar under road conditions. The results show that in a tarmacadam made with a low‐aromatic tar the hardening of the binder that occurs on the road is entirely due to oxidation. Oxidation accounts for about half of the hardening of high‐aromatic tars.
Aspects of the crystal structures of calcium silicates and aluminates
Authors: Taylor H. F. W. 
Published: July 2010

AbstractKnowledge of the crystal structures of both anhydrous and hydrated compounds is briefly reviewed, and the problem of relating crystallographic and chemical results is discussed. One approach lies in the study of oriented transformations, i.e., reactions in which the structure of a crystalline starting material is to a considerable extent preserved in that of the product. These include many dehydration reactions, such as those of xonotlite and afwillite, and also some typical hydrothermal processes such as the formation of xonotlite from tobermorite. Studies on oriented transformations at 650‐800° indicate that some reactions in this temperature range proceed through breaking of Si‐O rather than Ca‐O bonds. For dehydration reactions at lower temperatures, in contrast, there are indications that Si‐O bonds may be more stable than Ca‐O bonds. The feature common to all the types of transformations discussed is probably a tendency for the oxygen atoms or ions to move as little as possible.
An X‐ray study of pulverised fuel ash
Authors: Simons H. S. , Jeffery J. W. 
Published: July 2010

AbstractPulverised fuel ash has been subjected to X‐ray examination and chemical analysis and the main mineralogical and physical characteristics have been determined. It is shown that the ash is a very complex material in which the overall chemical composition varies from particle to particle.It is tentatively concluded that there is a positive correlation between pozzolanic activity and glass content. The types of combination of iron present in the ash have been determined and the effect of hydration examined.
Kinetics of oxidation of coal. II. Comparison of the reactivities of four coals
Authors: Wood T. 
Published: July 2010

AbstractAn attempt has been made to measure the reactivities of four coals using the Warburg technique. Temperature is shown to be a significant factor; the precision of the method is insufficient to determine the influence of particle size. The method would be well suited for a large‐scale statistical survey to investigate the influence of pyrites, or any other constituent, on the reactivity of a coal.
Oxidation of hydrazine in aqueous solution
Authors: Ellis S. R. M. , Jeffreys G. V. , Hill P. 
Published: July 2010

AbstractA description is given of the batch reactor employed to investigate the chemical reaction between hydrazine and oxygen in slightly alkaline aqueous solution. The results of the investigation are presented in graphical form, and an attempt has been made to interpret the data kinetically. It has been shown that the reaction is complex and is best described by an empirical rate equation.
Reaction with hydrofluoric acid of oxygen‐ and hydrogen‐containing zirconium and the structure of the alloy
Authors: Straumanis M. E. , James W. J. , Lin C. S. 
Published: July 2010

AbstractFrom dissolution experiments of the respective zirconium alloys in HF it is shown that oxygen is not occluded in zirconium, but is bound to form domains of ionised ZrO2, which may agglomerate to ZrO2 grains, sparingly soluble in HF while the alloy is soluble in dilute HF. Conversely, hydrogen is occluded or dissolved in zirconium (forming ZrHx), but probably only in those parts of the metal which are free of Zr4+ and O2‐ ions (of ZrO2). Thus the solubility of H2 in this free Zr should be higher than that usually reported by various authors who consider only the weight of oxygen.When ZrHx is dissolved in HF, the Hx is quantitatively liberated as a gas; ZrO2 when present in the samples and especially when present as a surface film remains as a residue.
Inhibitors of the corrosion of iron. II. Efficiency of the sodium, calcium and lead salts of long chain fatty acids
Authors: Mayne J. E. O. , Ramshaw E. H. 
Published: July 2010

AbstractThe inhibitive properties of the sodium, calcium and lead salts of caproic, oenanthic, caprylic, pelargonic, capric, suberic, azelaic and sebacic acids have been examined in the pH range 4·0–6·0 at concentrations 10−5 to 10−2 N.The inhibitive efficiency increased with the length of the carbon chain up to a maximum at 8–9 carbon atoms. For a given acid the lead salt was more efficient than either the sodium or the calcium salt. The most inhibitive salts examined were lead suberate and azelate.
Adhesion in bitumen macadam
Authors: Hughes R. I. , Lamb D. R. , Pordes O. 
Published: July 2010

AbstractLoss of adhesion between a bituminous binder and stone in the presence of water may take place by the retraction of the binder. It is suggested that this mechanism only operates when the viscosity of the binder is low. When loss of cohesion occurs in a carpet it more normally originates from the accumulation of water at the binder/stone interface leading to a condition in which the binder may be peeled cleanly away from the stone surface. This detachment occurs equally with bitumens and tars and, under traffic stresses, may lead to the loss of cohesion which, although comparatively rarely, sometimes leads to surface disintegration.Pretreatment of the mineral surface with certain metal salts may delay for several months the initial state of detachment, whereas this state cannot be prevented or delayed for more than a few days by the addition of wetting additives to the binder. Such additives, however, may modify the subsequent degree of detachment and very much reduce the loss of cohesion which may follow under the action of traffic. Loss of cohesion in these circumstances can also be reduced by the presence in the binder of components which have no possitive wetting tendency but confer a certain interfacial rigidity.It is tentatively suggested that the condition of detachment is due to the absorption of water into the silicate lattice to give a weakened gel‐like structure and cause a rise in pH value at the surface of the mineral. This rise in pH value is thought to be responsible for the inability of wetting additives to prevent the initial state of detachment being reached.Liability to detach is determined by the chemical nature of the aggregate and may not occur with minerals containing high proportions of more basic components particularly those containing iron. Under most conditions of stressing, the bond strength in the detached state is equivalent to that in the dry state although after prolonged immersion the resistance to tangential stresses may be relatively small. When the system dries out, reattachment may occur. These factors may help to explain why there is no direct relationship between the initial state of detachment and behaviour in practice.
Influence of solvent viscosity on the kinetics of the exchange of sodium for hydrogen ions in fixed beds of dowex‐50
Authors: Nutt C. W. , Sharifi S. , Tonge F. 
Published: July 2010

AbstractBreak‐through curves for the exchange of Na+ ions in 0·1 n‐NaCl in glycerol‐water mixtures for H+ ions in a fixed bed of Dowex‐50‐resin have been determined for Reynolds numbers from 0·01 to 2. Solutions containing up to 75% by vol. of glycerol and having viscosities up to 30 centipoise at 25° were used. Some measurements were also made on 0·1 n‐NaCl in ‘Polycell’ solutions in water. Small concentrations of this substance increase the viscosity of the system considerably with little effect on the ionic diffusivity. Effluent compositions and ionic diffusivities were determined by electrical conductivity. The total resistances to mass‐transfer were calculated from the slopes of the break‐through curves and values of the liquid film resistance estimated by the method of Gilliland & Baddour.2 The observed values of the liquid film coefficient could be correlated with flow rate, solution viscosity, and ionic diffusivity by the equation: kLD2/DL = 0·5 × Re0·83 × Sc0·75
Sucrose monoacetate
Authors: Kononenko O. K. , Kestenbaum I. L. 
Published: July 2010

AbstractSucrose monoacetate was prepared by acetylation of sucrose in pyridine solution. Recrystallization from isopropyl alcohol gave a product in pure form, as was shown by paper chromatography, while some higher acetates were detected in mother liquors. The properties of the new compound suggest possible application in two fields: as a humectant similar to sorbitol, but twice as effective as the latter, and as a potential nutritious carrier for food flavours with most properties of sucrose but the sweetness greatly reduced.
Reactivity of lime and related oxides. VI. crystal changes in carbonatated lime at different temperatures
Authors: Glasson D. R. 
Published: July 2010

AbstractThe ‘wet’ carbonatation of calcium hydroxide has been compared at 22° and 95° to determine the effect of temperature on the rate of formation, solubility and subsequent rate of ageing of the products, as indicated by changes in lattice structure and in surface area and average crystallite size. Direct precipitation of calcium carbonate from solution by double decomposition has been similarly compared, the conversion of the aragonitic and vateritic products to calcite being studied in solution at 95° and 22°, and in the solid state at temperatures up to 450°. Partly‐carbonatated lime has been hydrated to assess the extent to which the carbonate layer around each lime crystal inhibits further hydration.In ‘wet’ carbonatation at lower pH levels (8–12), especially in the presence of bicarbonate ions, the calcium carbonate layer developed around each lime particle ages more rapidly at the higher temperature, becoming almost non‐porous before carbonatation is complete; at higher pH levels, the carbonate is more porous, and splits off more readily. Similar ageing of calcite inhibits the conversion of aragonite to calcite. In highly alkaline media, at pH 13–14, the conversion of both aragonite and of vaterite to calcite are inhibited at 95°, but occurs readily in the solid state above 400° with considerable loss of surface area, vaterite also sintering extensively at 300°. When partly‐carbonatated lime is hydrated, the presence even of thin carbonate layers reduces the splitting of the lime particles, and the capacity of the carbonate to age afterwards partly restores their stability.
(II) Zinc
Authors: Allbutt M. , Tolley G. 
Published: July 2010

AbstractRates of solution of zinc in aqueous and dioxan solutions of hydrochloric acid are determined by weight loss and hydrogen evolution measurements. It is shown that the reaction between zinc and HCl in aqueous solutions is partly controlled by diffusion processes. With stirring sufficiently vigorous to eliminate this effect the rate is proportional to the mean ionic activity of HCl, and this is consistent with direct participation of chloride ions in the anodic reaction. Dioxan causes a change of reaction mechanism due, it is suggested, to its adsorption on the metal surface, inhibition of normal electrode processes, and promotion of a direct reaction between zinc and HCl molecules.
Organic constituents of gelatins and animal glues. III. Survey of the occurence of mucosubstances in gelatins and glues
Authors: Williams A. P. 
Published: July 2010

AbstractA survey of the occurrence of the mucosubstances reported in the first two papers of this series1,2 is reported. Certain modifications of the isolation techniques necessary for use with high‐grade gelatins and glues are described.