bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chromium hexacarbonyl. I. The preparation and stability of chromium hexacarbonyl
Authors: Cumming W. M. , Horn J. A. , Ritchie P. D. 
Published: July 2010

AbstractI. Recorded methods for preparing chromium hexacarbonyl are reviewed and critically compared. Previous theories on the mechanism of formation from carbon monoxide, chromic chloride, and a Grignard reagent are not wholly satisfactory, and an alternative mechanism is proposed, entailing the formation of an intermediate organo‐chromium‐III dibaiide.II. Hydrocarbon solutions of chromium hexacarbonyl are decomposed on exposure, in the presence of oxygen, to radiation in the near ultra‐violet, forming an insoluble gelatinous precipitate. In the presence of a molar equivalent of a long‐chain fatty acid, such as stearic acid, precipitation is inhibited, though the carbonyl still decomposes to hydrocarbon‐soluble products. The mechanism of decomposition and inhibition is still obscure.
Purification of potassium nitrate process liquors: Comparison between the filtration, froth flotation and sedimentation of insolubles
Authors: Chodkiewicz S. A. 
Published: July 2010

AbstractThe removal of kaolin, mechanical impurities and calcium, magnesium and iron ions from potassium nitrate process liquor was investigated. The addition of potassium alum and soda‐ash resulted in the removal of the soluble impurities and gave rapid settling of the solids. With the help of potassium oleate and Turkey‐red oil the solids can be removed by means of froth flotation, and this method requires only a small sized installation. The filtration using a sand filter or a filter press proved to be uneconomical owing to the unfavourable filtration characteristics of the impurities.
Physico‐chemical studies on dusts. IV. Accuracy of chemical estimation of free silica in rocks and mineral dusts
Authors: Cumming W. M. , Dempster P. B. , Ritchie P. D. 
Published: July 2010

AbstractThe method of Trostel & Wynne (1940) for the estimation of free silica has been applied to the analysis of coal‐measure rocks, and its suitability critically studied. If two fusions and alkali extractions are carried out, and if corrections are applied for the quartz lost during analysis, and for the presence of resistant minerals, the analytical accuracy is ± 2% in the absence of chalcedonic silica. In its presence the result is low, since the loss of chalcedonic silica during analysis is greater than that of quartz. The method cannot be used to estimate accurately the free silica content of mixtures containing both quartz and cristobalite, since the loss from cristobalite during analysis is again greater than that from quartz.
The preparation of 3:5‐dimethyl‐1‐phenyl‐1:2:4‐triazole
Authors: Komzak A. A. , Polya J. B. 
Published: July 2010

AbstractOptimum conditions for the laboratory‐scale preparation of 3 : 5‐dimethyl‐1‐phenyl‐1 : 2 : 4‐triazole by the Einhorn‐Brunner method have been studied. The mechanism of the reaction is different from those involved in the triazole syntheses of Pellizzari and Kaiser.
The heat treatment of dolomite. I. The ‘activity’ of lime and of magnesia in relation to their temperature of preparation
Authors: Britton H. T. S. , Gregg S. J. , Winsor G. W. 
Published: July 2010

AbstractSamples of calcium carbonate and of magnesium carbonate have been calcined for two hours at a succession of fixed temperatures in the range 600° to 1400°. The ‘activity’ of the product–assessed by measurements of the rates of dissolution, of slaking, and of bulk density–shows a maximum at about 900° for calcium oxide and at about 700° for magnesium oxide. A tentative explanation is proposed.
Polycyclic aromatic hydrocarbons as starting materials for the synthesis of dyestuffs
Authors: Holbro Th. 
Published: July 2010

AbstractThis paper is a survey of recent research on the technical use of polycyclic aromatic hydrocarbons, which are now available in large quantities, in the synthesis of dyestuffs. This work has shown that the inclusion of these hydrocarbons may have a beneficial effect on the properties of the dyestuffs. The most interesting results were obtained with the tetracyclic compounds chrysene, pyrene and fluoranthene, for which technical use could be found, particularly in the synthesis of high‐quality dyes, e.g. anthraquinone vat‐dyes.
Sodium benzoate and sodium nitrite as corrosion‐inhibitors in ethylene glycol anti‐freeze solutions. I. Laboratory investigations
Authors: Wormwell F. , Mercer A. D. 
Published: July 2010

AbstractThe addition of 1·5% sodium benzoate and 0·1% sodium nitrite to a 20% ethylene glycol anti‐freeze solution effectively prevents corrosion of cast iron and soldered joints in conditions of intermittent heating. In the absence of benzoate, sodium nitrite protects cast iron but increases the attack on soldered joints in glycol solutions, the intensity of attack increasing considerably over the range 0·1 to 1·5% sodium nitrite.A short initial period of heating is necessary to ensure complete protection of cast iron in 20% glycol solution containing 1·5% sodium benzoate + 0·1% sodium nitrite. At room temperature without initial heating, 0·3% sodium nitrite is required to protect machined cast iron in 20% glycol solution containing 1·0 or 1·5% sodium benzoate; with 30% glycol and 1·0 or 1·5% sodium benzoate, 0·1% nitrite is sufficient. With ‘as‐cast’ surfaces higher concentrations of sodium nitrite are required to prevent rusting.
The attack of metals by free radicals and atoms
Authors: Thompson F. W. , Ubbelohde A. R. 
Published: July 2010

AbstractNumerous but scattered reactions are known where the surfaces of metal containers are attacked during the chemical changes in contiguous gases or liquids. In many cases the basic physico‐chemical interpretation of such attack is incomplete. In the present paper a number of examples are discussed in terms of thermodynamics and kinetics.A consideration of the kinetics may involve atoms or free radicals, and a transient concentration of these may be established which greatly exceeds the equilibrium concentration. This can favour internal reduction of metal carbides, nitrides, sulphides and oxides and can lead to extremely high disruption‐pressures at internal voids in the metal.Other cases of enhanced attack on metal surfaces due to transient concentrations of atoms and free radicals are also discussed.
Acetylene studies. II. The condensation of acetylene with aldehydes and ketones
Authors: Bergmann Ernst D. , Sulzbacher Max , Herman Daniel F. 
Published: July 2010

AbstractThe preparation of acetylenic carbinols and glycols is described, using as condensing agent the system potassium hydroxide plus acetals (or ethylene glycol dialkyl ethers); this system has an optimum absorption of acetylene at 80°. The mechanism of the reaction is discussed.
Acetylene studies. III. Preparation and reactions of the acetyldialkylcarbinols
Authors: Bergmann Ernst D. , Herman Daniel F. 
Published: July 2010

AbstractThe hydration of the dialkylethynylcarbinols, and the reactivity of the acetyldialkylcarbinols so obtained, i.e. hydrogenation to secondary‐tertiary glycols (and the reactions of the glycols) and reductive animation, have been studied. The amino‐alcohols so prepared, which contain a tertiaryhydroxyl and a primary‐ (or secondary‐) amino group, give Schiff bases or oxazolidines with aldehydes and ketones, and 2‐mercapto‐oxazolines with carbon disulphide or thiocarbonyl chloride. They also condense easily with 1‐halogenoanthraquinones (with their amino group).
The determination of phenolic hydroxyl values (semi‐micro method)
Authors: Brunner H. , Thomas H. R. 
Published: July 2010

AbstractThe various factors affecting the accuracy and procedure of hydroxyl determination are discussed. Phenolic acetates have been found to hydrolyse fairly rapidly during the hydrolysis of anhydrides, a process which is normally carried out at the end of the acetylation reaction, and this is held to account for anomalous hydroxyl values obtained previously for phenolic substances.A satisfactory semi‐micro procedure has been developed for use with samples of phenols (20 to 80 mg.).In determining the acid values of phenols and phenolic‐resin intermediates the use of phenolphthalein as indicator is to be avoided. Neutral red is suggested as a suitable indicator.
Determination of sulphate and sulphonate anion‐active detergents in sewage
Authors: Degens P. N. , Evans H. C. , Kommer J. D. , Winsor P. A. 
Published: July 2010

AbstractVery small amounts of anionic synthetic detergents can be quickly estimated by a modification of the method originally employed by Jones. The effects of various interfering substances can usually be eliminated by a suitable choice of the volume ratio of aqueous and organic phases, and by the number of extractions. However, the effect of thiocyanate at concentrations greater than 5 p.p.m. cannot be wholly eliminated in this way, and two alternative methods of removal by chemical reaction are described. Sulphate and sulphonate detergents can be separately estimated by hydrolysing the sulphates in boiling acid solution and measuring the detergent content before and after treatment. More details of the method are given in the Appendix.
The brittle fracture of tars and bitumens
Authors: Rigden P. J. , Lee A. R. 
Published: July 2010

AbstractAs part of a study of the cracking and disintegration of bituminous road‐surfacing materials, measurements have been made of the tensile strength of tars and bitumens, of tars to which filler has been added, and of tars after exposure to the action of weather. Measurements have also been made of the Fraass brittle temperatures of the materials.Under conditions of test in which there is no flow, tars, pitches and bitumens have the same brittle tensile strength of about 6 kg./cm.2; this value, which was obtained for materials tested in moulds that imposed lateral restraint, increases to about 30 kg./cm.2 when the specimen has no support at the position of fracture. Weathering of the materials has little effect on the brittle tensile strength, but the measured tensile strength increases considerably when the cross‐sectional area of the test specimen is reduced.A mathematical analysis of the Fraass brittle test has shown that it is an equi‐viscous temperature test measuring the temperature at which the material has a viscosity of approximately 4 × 109 poises.Although the addition of filler to tar increases the brittle tensile strength, no significant change is produced in the Fraass brittle temperature because there is a corresponding increase in viscosity.
The role of tannates and phosphates in the preservation of ancient buried iron objects
Authors: Farrer T. W. , Biek L. , Wormwell F. 
Published: July 2010

AbstractArchaeological specimens of iron are occasionally found to be well preserved under conditions that would normally be regarded as highly aggressive. A striking example arose during excavations at Hungate, York, where iron articles were found in an excellent state of preservation after a period of about 2000 years. Investigation revealed that the lack of corrosion was attributable mainly to inhibition of the activity of sulphate‐reducing bacteria by tannates present in the soil. Phosphates likewise present probably assisted by reason of their known corrosion‐inhibitive properties.
Separation of phenols from coal‐tar hydrocarbons by means of glycerol and aqueous triethylene glycol: Development of a process
Authors: Cumming A. P. C. 
Published: July 2010

AbstractThe present paper is an extension of the work on the extraction of phenol from coal‐tar hydrocarbons, and deals with the separation of mixed phenols from coal‐tar hydrocarbons boiling in the range 170–201°. By subsequent treatment of the extract, a final mixed‐phenols product can be produced containing 0·1% of hydrocarbons or less. The outlines of a process for this separation are included.
The action of metallic nickel on bismuth trichloride
Authors: Cornish E. H. 
Published: July 2010

AbstractNickel reacts with dilute aqueous solutions of bismuth trichloride with deposition of elementary bismuth. There is, however, a range of concentration of the salt within which nickel has no action at 25°. At higher temperatures other factors intervene and smooth reaction occurs. The rate of reaction is increased by moderate stirring but decreases with increasing acid concentration.
Flow of concentrated suspensions
Authors: Williams P. S. 
Published: July 2010

AbstractPart I of the paper deals with the general properties of the flow of concentrated suspensions. The shear stress/rate of shear characteristics of Newtonian, non‐Newtonian, plastic and thixotropic types of flow are briefly set out. The types of suspensions encountered in the paint industry and their flow properties are described, and it is concluded that no generalization is yet possible on the effect of particle size, shape or nature of the chemical interface.In Part II some recent research on the flow of glass spheres in simple liquids is reported: glass spheres were used because they are geometrically simple and are easily made, and the methods of preparing and fractionating them into different size ranges are described. The importance and difficulty of particle‐size analysis are discussed. Results obtained with suspensions containing different concentrations of spheres with different size‐distributions are given and it is found that the particle‐size distribution very much affects the viscosities of suspensions with more than about 30% of spheres by volume. It was found that the more nearly the particle sizes are equal to each other, the lower is the concentration of spheres required for a given viscosity. It was also found that for particle sizes less than 1/μ in diameter, the smaller the size, the greater the thixotropy.
Acetylene studies. V. Diels‐alder reactions with methylchloroprene
Authors: Bergmann Ernst D. 
Published: July 2010

Abstract3‐Chloro‐2‐methylbutadiene (methylchloroprene), which can be prepared from ethynyldimethyl‐carbinol by dehydration and addition of hydrochloric acid, gives the normal Diels‐Alder reaction with butyl fumarate, maleic and chloromaleic anhydrides, p‐benzoquinone, acrylonitrile, methyl methacrylate, α‐hydroxyisopropyl vinyl ketone and ββ‐dimethylacrolein, but not with crotonaldehyde, crotonic acid, methyl isopropenyl ketone and ethynyldimethylcarbinol.
The determination of the critical constants of liquid explosives
Authors: Lewis D. T. 
Published: July 2010

AbstractThe critical constants of liquid explosives cannot be measured directly because of the intractable nature of the substances concerned. Equations are developed in this paper whereby the critical temperatures and critical densities of liquid explosives may be determined with a high degree of accuracy from measurements made in an accessible range of the densities and surface tensions of the explosives concerned.In order to illustrate the application of these equations the critical constants of 2:4:6‐trinitrotoluene (TNT), nitroglycerin and mercury have been calculated and the relationships employed are shown to be of general applicability to a wide range of chemical substances.The surface tensions of TNT have been experimentally determined, and it is shown that this explosive, when in the liquid state, has normal characteristics.
The separation and determination of mixtures of chlorinated o‐cresols
Authors: Freeman F. , Gardner K. , Pound D. W. 
Published: July 2010

AbstractMethods of separation of the products of chlorination of o‐cresol are described. The procedure adopted for preparation of the pure chloro‐o‐cresols is outlined, and the development of a rapid method for the estimation of the four cresols appearing in the chlorination product is traced. The method consists in separating, by partition chromatography on kieselguhr, the mixture into two fractions, 6‐chloro‐o‐cresol + 4 : 6‐dichloro‐o‐cresol and o‐cresol + 4‐chloro‐o‐cresol. The components of these fractions are estimated differentially by ultra‐violet spectrophotometry. Results are shown for analysis of mixtures of the pure cresols.
Simplified low‐speed rotor techniques for corrosion testing
Authors: Wormwell F. 
Published: July 2010

AbstractSeveral simplified rotor techniques are described. Corrosion is appraised by the measurement of weight‐loss or depth of pitting on specimens in round‐rod or sheet form. With single cylindrical specimens, electrode potentials have been measured under conditions of rotation. The results help to explain the influence of cathodic and anodic polarization on the corrosion of mild steel in sea‐water.
The aggregation of kaolinite
Authors: Gregg S. J. , Hill K. J. 
Published: July 2010

AbstractA series of fractions of kaolin [smaller than 0.5, 0.5–1, 1–2.5, 2.5–5, 5–10 and 10–20 μ in equivalent Stokes' diameter (E.S.D.)] separated by sedimentation have been investigated by measuring the specific surface area, SA, by gas sorption, the heat of immersion in carbon tetrachloride, the bulk volume, V, and the apparent density in various liquids; the ‘percentage floating in air after five seconds,’ f, has also been determined by dropping down a long glass tube. The value of SA agrees reasonably with the specific area, SD, calculated from the E.S.D. for the 0.5, 0.5–1, and 1–2.5‐μ fractions, but SA/SD then increases with increasing E.S.D. to nearly 4 for the 10–20‐μ fraction; moreover both V (whether measured ‘in air’ or ‘in vacuo’) and f have maximal values for the 1–2.5‐μ fraction. The results point to the existence of two types of aggregate : (a) temporary and loose aggregates in the three smallest particle sizes, and (b) ‘booklets’ in the three largest sizes.
The influence of molecular structure on the oxidation of aliphatic hydrocarbons
Authors: Small N. J. H. , Ubbelohde A. R. 
Published: July 2010

AbstractFrom a review of existing studies on the oxidation of hydrocarbons, the relationship between structure and ease of oxidation at low temperatures appears to be quite anomalous, compared with most other hydrocarbon reactions.Recent experimental results indicate that the anomalous relationship between structure and reactivity is associated particularly with the fate of the energy‐rich peroxide radical, R·*, whose formation and reaction are generally writtenFactors which may favour reaction (b) include a low energy of transfer of hydrogen from RH to RO2·, and a high energy content made available for activation by vibration coupling within the hydrocarbon molecule. Collisions of RO2· with hydrogen or mercury hinder reaction (b). In addition to possible vibrational‐energy activation it is suggested that RO2· may exist in more than one electronic state, with different energy contents.
Thermodynamics of formaldehyde manufacture from methanol
Authors: Jones Elwyn , Fowlie G. G. 
Published: July 2010

AbstractThe production of formaldehyde from methanol, either by thermal decomposition, by catalytic oxidation or by a combination of the two, is treated as an exercise in chemical thermodynamics. Simple dehydrogenation of methanol does not appear attractive because it requires temperatures which tend to produce decomposition of the formaldehyde as it is formed. Oxidation of methanol to formaldehyde and steam requires the agency of a catalyst which is active in the region of 300°, the ideal working mixture for an insulated catalyst containing roughly 5 1/2 to 8% of methanol in air. The composite process, in which dehydrogenation and oxidation occur simultaneously, offers certain advantages, and may be expected to give maximum efficiency in the range 500–700°, corresponding to methanol/air mixtures containing 45 to 37% of methanol. Addition of steam to the reacting mixture lowers the catalyst temperature and modifies the product composition accordingly. Rapid cooling of the products to about 300° is essential to avoid regeneration of methanol and decomposition of formaldehyde. An interesting feature is that the straight oxidation‐process operates with mixtures of methanol and air at or just below the lower inflammability limit, whereas the composite process requires mixtures at or above the upper inflammability limit.
The use of the Eschka method for the determination of high sulphur contents
Authors: Mott R. A. , Wilkinson H. C. 
Published: July 2010

AbstractIt is shown that the incineration period for determining sulphur in coal can be reduced, in a well ventilated muffle, to I hour at 775–800°, for a 1‐g. sample with 4 g. of Eschka mixture. The same time can be used for high sulphur contents with 0° i‐g. samples. The essential feature in obtaining complete precipitation of the sulphate ion is to ensure adequate excess of barium chloride of which 10 ml. of 10% BaCl2,2H2O is adequate for sulphur up to 0·08 g., a similar excess being obtained by using 10 ml. with 0·1‐g. samples for sulphur contents of 8–80%. For sulphur contents higher than 80%, 0·1–g. samples, with 70% excess of barium chloride, should be used.It is shown that the barium sulphate precipitate is most quickly and accurately determined by igniting the wet filter‐paper in a well ventilated muffle, with precautions to avoid shock‐heating.
Use of the membrane filter in the bacteriological examination of water
Authors: Taylor E. Windle , Burman N. P. , Oliver C. W. 
Published: July 2010

AbstractMolecular or milli‐pore filter membranes have been used for a number of years in Europe. The Goetz type, recently introduced in America, not only retains all micro‐organisms from a large volume of liquid but also can be placed in contact with an absorbent pad soaked with concentrated nutrient solution; this solution passes through the pores of the membrane to the bacteria deposited on its surface, so that they can be cultivated in situ.The work described below is a preliminary survey to assess the possibility of applying membrane‐filter technique to media and methods commonly used in Britain for the bacteriological examination of water. The chief advantages of the technique are concentration of micro‐organisms, removal of inhibitory substances and saving in glassware and in media preparation.Further investigations proposed include the examination of a series of samples, the development of a procedure for achieving a rapid result and the isolation of pathogenic organisms from sewage effluents and polluted waters.
New ω‐substituted anisoles. II. Aryloxymethanesulphonates: Reactions
Authors: Barber H. J. , Cottrell H. J. , Green M. B. 
Published: July 2010

AbstractAryloxymethanesulphonic acids, ArO·CH2·SO3H, and their salts are fairly resistant to hydrolysis and can be nitrated and chlorinated. The sulphomethoxyl group is ortho–para‐directing in the ratio of about 1:10. 4‐Nitrophenoxymethanesulphonic acid can be reduced to the sparingly water‐soluble 4‐aminophenoxymethanesulphonic acid, the amino group of which retains its aromatic character and can be diazotized and coupled. Alkyl‐substituted aryloxymethanesulphonic acids can be oxidized to the corresponding carboxylic acids. On treatment of aryloxymethanesulphonates with chlorinating agents the SO3H group is replaced by Cl, with the formation of phenoxymethyl chlorides, ArO·CH2Cl. Aryloxymethanesulphonic acid esters can be obtained by treatment of the silver salt of the sulphonic acid with an alkyl iodide.